def test_alpha_warning(self):
"""
Test if alpha_conductor warns when t < 3 * skin_depth
"""
# cpw line on 1.5mm FR-4 substrate
freq = Frequency(1, 1, 1, 'MHz')
with self.assertWarns(RuntimeWarning) as context:
cpw = CPW(frequency = freq, z0 = 50., w = 3.0e-3, s = 0.3e-3, t = 35e-6,
ep_r = 4.5, rho = 1.7e-8)
line = cpw.line(d = 25e-3, unit = 'm', embed = True, z0 = cpw.Z0)
def test_qucs_network(self):
"""
Test against the Qucs project results
TODO : finalize
"""
# create an equivalent skrf network
cpw = CPW(frequency=self.freq,
w=75e-6,
s=50e-6,
ep_r=12.9,
rho=0.22e-6)
ntw = self.cpw2.thru(z0=50)**cpw.line(d=1,
unit='m')**self.cpw2.thru(z0=50)
def setUp(self):
'''
this also tests the ability to read touchstone files
without an error
'''
setup_pylab()
self.test_dir = os.path.dirname(os.path.abspath(__file__)) + '/'
self.ntwk1 = rf.Network(os.path.join(self.test_dir, 'ntwk1.s2p'))
self.ntwk2 = rf.Network(os.path.join(self.test_dir, 'ntwk2.s2p'))
self.ntwk3 = rf.Network(os.path.join(self.test_dir, 'ntwk3.s2p'))
self.freq = rf.Frequency(75, 110, 101, 'ghz')
self.cpw = CPW(self.freq, w=10e-6, s=5e-6, ep_r=10.6)
l1 = self.cpw.line(0.20, 'm', z0=50)
l2 = self.cpw.line(0.07, 'm', z0=50)
l3 = self.cpw.line(0.47, 'm', z0=50)
self.Fix = rf.concat_ports([l1, l1, l1, l1])
self.DUT = rf.concat_ports([l2, l2, l2, l2])
self.Meas = rf.concat_ports([l3, l3, l3, l3])
def setUp(self):
self.frequency = rf.Frequency(75, 110, 101, 'ghz')
self.media = CPW(\
frequency=self.frequency,
w=10e-6,
s=5e-6,
ep_r=11.7,
t=1e-6,
rho=22e-9)
def setUp(self):
self.files_dir = os.path.join(
os.path.dirname(os.path.abspath(__file__)), 'qucs_prj')
fname = os.path.join(self.files_dir, 'cpw.s2p')
self.qucs_ntwk = rf.Network(fname)
# create various examples
self.freq = rf.Frequency(start=1, stop=20, npoints=21, unit='GHz')
# infinite dielectric substrate, infinitely thin metal
self.cpw1 = CPW(frequency=self.freq, w=40e-6, s=20e-6, ep_r=3)
# infinite GaAs substrate, infinitely thin metal
self.cpw2 = CPW(frequency=self.freq, w=75e-6, s=50e-6, ep_r=12.9)
# infinite GaAs substrate, finite metal thickness
# TODO: not used yet
self.cpw3 = CPW(frequency=self.freq,
w=75e-6,
s=50e-6,
ep_r=12.9,
t=1e-6)
def test_Z0_vs_f(self):
"""
Test the CPW Characteristic Impedance vs frequency.
Reference data comes from Qucs Documentation (Fig 12.2)
"""
w_over_s_qucs, Z0_qucs = npy.loadtxt(
os.path.join(self.data_dir_qucs, 'cpw_qucs_ep_r9dot5.csv'),
delimiter=';', unpack=True)
w = 1
Z0 = []
for w_o_s in w_over_s_qucs:
# simulate infinite thickness by providing h >> w
_cpw = CPW(frequency=self.freq[0], w=w, s=w/w_o_s, h=1e9, ep_r=9.5)
Z0.append(_cpw.Z0[0].real)
# all to a 3% relative difference
# this is quite a large discrepancy, but I extracted the ref values from the plot
# one could do better eventually by extracting values from Qucs directly
rel_diff = (Z0_qucs-npy.array(Z0))/Z0_qucs
self.assertTrue(npy.all(npy.abs(rel_diff) < 0.03))
def test_Z0_vs_f(self):
"""
Test the CPW Characteristic Impedance vs frequency.
Reference data comes from Qucs Documentation (Fig 12.2)
"""
w_over_s_qucs, Z0_qucs = npy.loadtxt(os.path.join(
self.files_dir, 'cpw_qucs_ep_r9dot5.csv'),
delimiter=';',
unpack=True)
w = 1
Z0 = []
for w_o_s in w_over_s_qucs:
_cpw = CPW(frequency=self.freq[0], w=w, s=w / w_o_s, ep_r=9.5)
Z0.append(_cpw.Z0[0].real)
# all to a 3% relative difference
# this is quite a large discrepancy, but I extracted the ref values from the plot
# one could do better eventually by extracting values from Qucs directly
rel_diff = (Z0_qucs - npy.array(Z0)) / Z0_qucs
assert_allclose(rel_diff - 3 / 100, 0, atol=0.1)
class NetworkTestCase(unittest.TestCase):
'''
Network class operation test case.
The following is true, as tested by lihan in ADS,
test3 == test1 ** test2
To test for 2N-port deembeding Meas, Fix and DUT are created such as:
::
Meas == Fix ** DUT
Meas Fix DUT
+---------+ +---------+ +---------+
-|0 4|- -|0 4|---|0 4|-
-|1 5|- = -|1 5|---|1 5|-
-|2 6|- -|2 6|---|2 6|-
-|3 7|- -|3 7|---|3 7|-
+---------+ +---------+ +---------+
Note:
-----
due to the complexity of inv computations, there will be an unavoidable
precision loss. thus Fix.inv ** Meas will show a small difference with DUT.
'''
def setUp(self):
'''
this also tests the ability to read touchstone files
without an error
'''
setup_pylab()
self.test_dir = os.path.dirname(os.path.abspath(__file__)) + '/'
self.ntwk1 = rf.Network(os.path.join(self.test_dir, 'ntwk1.s2p'))
self.ntwk2 = rf.Network(os.path.join(self.test_dir, 'ntwk2.s2p'))
self.ntwk3 = rf.Network(os.path.join(self.test_dir, 'ntwk3.s2p'))
self.freq = rf.Frequency(75, 110, 101, 'ghz')
self.cpw = CPW(self.freq, w=10e-6, s=5e-6, ep_r=10.6)
l1 = self.cpw.line(0.20, 'm', z0=50)
l2 = self.cpw.line(0.07, 'm', z0=50)
l3 = self.cpw.line(0.47, 'm', z0=50)
self.Fix = rf.concat_ports([l1, l1, l1, l1])
self.DUT = rf.concat_ports([l2, l2, l2, l2])
self.Meas = rf.concat_ports([l3, l3, l3, l3])
def test_timedomain(self):
t = self.ntwk1.s11.s_time
s = self.ntwk1.s11.s
self.assertTrue(len(t) == len(s))
def test_time_gate(self):
ntwk = self.ntwk1
gated = self.ntwk1.s11.time_gate(0, .2)
self.assertTrue(len(gated) == len(ntwk))
def test_time_transform(self):
spb = (4, 5)
data_rate = 5e9
num_taps = (100, 101)
for i in range(2):
tps = 1. / spb[i] / data_rate
num_points = spb[i] * num_taps[i]
# Frequency terms should NOT contain Nyquist frequency if number of points is odd
inc_nyq = True if num_points % 2 == 0 else False
freq = npy.linspace(0,
1. / 2 / tps,
num_points // 2 + 1,
endpoint=inc_nyq)
dut = self.ntwk1.copy()
freq_valid = freq[npy.logical_and(freq >= dut.f[0],
freq <= dut.f[-1])]
dut.interpolate_self(rf.Frequency.from_f(freq_valid, unit='hz'))
dut_dc = dut.extrapolate_to_dc()
t, y = dut_dc.s21.impulse_response(n=num_points)
self.assertEqual(len(t), num_points)
self.assertEqual(len(y), num_points)
self.assertTrue(npy.isclose(t[1] - t[0], tps))
t, y = dut_dc.s21.step_response(n=num_points)
self.assertEqual(len(t), num_points)
self.assertEqual(len(y), num_points)
self.assertTrue(npy.isclose(t[1] - t[0], tps))
def test_constructor_empty(self):
rf.Network()
def test_constructor_from_values(self):
rf.Network(f=[1, 2], s=[1, 2], z0=[1, 2])
def test_constructor_from_touchstone(self):
rf.Network(os.path.join(self.test_dir, 'ntwk1.s2p'))
def test_constructor_from_hfss_touchstone(self):
# HFSS can provide the port characteric impedances in its generated touchstone file.
# Check if reading a HFSS touchstone file with non-50Ohm impedances
ntwk_hfss = rf.Network(
os.path.join(self.test_dir, 'hfss_threeport_DB.s3p'))
self.assertFalse(npy.isclose(ntwk_hfss.z0[0, 0], 50))
def test_constructor_from_pathlib(self):
if sys.version_info.major == 3 and sys.version_info.minor >= 4: # pathlib added in 3.4
from pathlib import Path
rf.Network(Path(self.test_dir) / 'ntwk1.ntwk')
def test_constructor_from_pickle(self):
rf.Network(os.path.join(self.test_dir, 'ntwk1.ntwk'))
def test_constructor_from_fid_touchstone(self):
filename = os.path.join(self.test_dir, 'ntwk1.s2p')
with open(filename, 'rb') as fid:
rf.Network(fid)
def test_open_saved_touchstone(self):
self.ntwk1.write_touchstone('ntwk1Saved', dir=self.test_dir)
ntwk1Saved = rf.Network(os.path.join(self.test_dir, 'ntwk1Saved.s2p'))
self.assertEqual(self.ntwk1, ntwk1Saved)
os.remove(os.path.join(self.test_dir, 'ntwk1Saved.s2p'))
def test_pickling(self):
original_ntwk = self.ntwk1
with tempfile.NamedTemporaryFile(dir=self.test_dir,
suffix='ntwk') as fid:
pickle.dump(original_ntwk, fid,
protocol=2) # Default Python2: 0, Python3: 3
fid.seek(0)
unpickled = pickle.load(fid)
self.assertEqual(original_ntwk, unpickled)
def test_stitch(self):
tmp = self.ntwk1.copy()
tmp.f = tmp.f + tmp.f[0]
c = rf.stitch(self.ntwk1, tmp)
def test_cascade(self):
self.assertEqual(self.ntwk1**self.ntwk2, self.ntwk3)
self.assertEqual(self.Fix**self.DUT**self.Fix.flipped(), self.Meas)
def test_connect(self):
self.assertEqual(rf.connect(self.ntwk1, 1, self.ntwk2, 0) , \
self.ntwk3)
xformer = rf.Network()
xformer.frequency = (1, )
xformer.s = ((0, 1), (1, 0)) # connects thru
xformer.z0 = (50, 25) # transforms 50 ohm to 25 ohm
c = rf.connect(xformer, 0, xformer,
1) # connect 50 ohm port to 25 ohm port
self.assertTrue(
npy.all(npy.abs(c.s - rf.impedance_mismatch(50, 25)) < 1e-6))
def test_connect_multiports(self):
a = rf.Network()
a.frequency = (1, )
a.s = npy.arange(16).reshape(4, 4)
a.z0 = npy.arange(4) + 1 # Z0 should never be zero
b = rf.Network()
b.frequency = (1, )
b.s = npy.arange(16).reshape(4, 4)
b.z0 = npy.arange(4) + 10
c = rf.connect(a, 2, b, 0, 2)
self.assertTrue((c.z0 == [1, 2, 12, 13]).all())
d = rf.connect(a, 0, b, 0, 3)
self.assertTrue((d.z0 == [4, 13]).all())
def test_connect_fast(self):
raise SkipTest('not supporting this function currently ')
self.assertEqual(rf.connect_fast(self.ntwk1, 1, self.ntwk2, 0) , \
self.ntwk3)
xformer = rf.Network()
xformer.frequency = (1, )
xformer.s = ((0, 1), (1, 0)) # connects thru
xformer.z0 = (50, 25) # transforms 50 ohm to 25 ohm
c = rf.connect_fast(xformer, 0, xformer,
1) # connect 50 ohm port to 25 ohm port
self.assertTrue(
npy.all(npy.abs(c.s - rf.impedance_mismatch(50, 25)) < 1e-6))
def test_flip(self):
self.assertEqual(rf.connect(self.ntwk1, 1, self.ntwk2, 0) , \
self.ntwk3)
gain = rf.Network()
gain.frequency = (1, )
gain.s = ((0, 2), (0.5, 0)) # connects thru with gain of 2.0
gain.z0 = (37, 82)
flipped = gain.copy()
flipped.flip()
c = rf.connect(gain, 1, flipped, 0)
self.assertTrue(
npy.all(npy.abs(c.s - npy.array([[0, 1], [1, 0]])) < 1e-6))
def test_de_embed_by_inv(self):
self.assertEqual(self.ntwk1.inv**self.ntwk3, self.ntwk2)
self.assertEqual(self.ntwk3**self.ntwk2.inv, self.ntwk1)
self.assertEqual(self.Fix.inv**self.Meas**self.Fix.flipped().inv,
self.DUT)
def test_plot_one_port_db(self):
self.ntwk1.plot_s_db(0, 0)
def test_plot_one_port_deg(self):
self.ntwk1.plot_s_deg(0, 0)
def test_plot_one_port_smith(self):
self.ntwk1.plot_s_smith(0, 0)
def test_plot_two_port_db(self):
self.ntwk1.plot_s_db()
def test_plot_two_port_deg(self):
self.ntwk1.plot_s_deg()
def test_plot_two_port_smith(self):
self.ntwk1.plot_s_smith()
def test_zy_singularities(self):
open = rf.N(f=[1], s=[1], z0=[50])
short = rf.N(f=[1], s=[-1], z0=[50])
react = rf.N(f=[1], s=[[0, 1], [1, 0]], z0=50)
z = open.z
y = short.y
a = react.y
def test_conversions(self):
#Converting to other format and back to S-parameters should return the original network
s_random = npy.random.uniform(
-10, 10, (self.freq.npoints, 2,
2)) + 1j * npy.random.uniform(-10, 10,
(self.freq.npoints, 2, 2))
ntwk_random = rf.Network(s=s_random, frequency=self.freq)
for test_z0 in (50, 10, 90 + 10j, 4 - 100j):
for test_ntwk in (self.ntwk1, self.ntwk2, self.ntwk3, ntwk_random):
ntwk = rf.Network(s=test_ntwk.s, f=test_ntwk.f, z0=test_z0)
npy.testing.assert_allclose(
rf.a2s(rf.s2a(ntwk.s, test_z0), test_z0), ntwk.s)
npy.testing.assert_allclose(
rf.z2s(rf.s2z(ntwk.s, test_z0), test_z0), ntwk.s)
npy.testing.assert_allclose(
rf.y2s(rf.s2y(ntwk.s, test_z0), test_z0), ntwk.s)
npy.testing.assert_allclose(
rf.h2s(rf.s2h(ntwk.s, test_z0), test_z0), ntwk.s)
npy.testing.assert_allclose(rf.t2s(rf.s2t(ntwk.s)), ntwk.s)
npy.testing.assert_allclose(rf.t2s(rf.s2t(self.Fix.s)), self.Fix.s)
def test_sparam_conversion_with_complex_char_impedance(self):
'''
Renormalize a 2-port network wrt to complex characteristic impedances
using power-waves definition of s-param
Example based on scikit-rf issue #313
'''
f0 = rf.Frequency(75.8, npoints=1, unit='GHz')
s0 = npy.array([[-0.194 - 0.228j, -0.721 + 0.160j],
[-0.721 + 0.160j, +0.071 - 0.204j]])
ntw = rf.Network(frequency=f0, s=s0, z0=50, name='dut')
# complex characteristic impedance to renormalize to
zdut = 100 + 10j
# reference solutions obtained from ANSYS Circuit or ADS (same res)
# case 1: z0=[50, zdut]
s_ref = npy.array(
[[[-0.01629813 - 0.29764199j, -0.6726785 + 0.24747539j],
[-0.6726785 + 0.24747539j, -0.30104687 - 0.10693578j]]])
npy.testing.assert_allclose(rf.z2s(ntw.z, z0=[50, zdut]), s_ref)
npy.testing.assert_allclose(
rf.renormalize_s(ntw.s, [50, 50], [50, zdut]), s_ref)
# case 2: z0=[zdut, zdut]
s_ref = npy.array([[[
-0.402829859501534 - 0.165007172677339j,
-0.586542065592524 + 0.336098534178339j
],
[
-0.586542065592524 + 0.336098534178339j,
-0.164707376748782 - 0.21617153431756j
]]])
npy.testing.assert_allclose(rf.z2s(ntw.z, z0=[zdut, zdut]), s_ref)
npy.testing.assert_allclose(
rf.renormalize_s(ntw.s, [50, 50], [zdut, zdut]), s_ref)
# Compararing Z and Y matrices from reference ones (from ADS)
# Z or Y matrices do not depend of characteristic impedances.
# Precision is 1e-4 due to rounded results in ADS export files
z_ref = npy.array([[[34.1507 - 65.6786j, -37.7994 + 73.7669j],
[-37.7994 + 73.7669j, 55.2001 - 86.8618j]]])
npy.testing.assert_allclose(ntw.z, z_ref, atol=1e-4)
y_ref = npy.array([[[0.0926 + 0.0368j, 0.0770 + 0.0226j],
[0.0770 + 0.0226j, 0.0686 + 0.0206j]]])
npy.testing.assert_allclose(ntw.y, y_ref, atol=1e-4)
def test_sparam_conversion_vs_sdefinition(self):
'''
Check that power-wave or pseudo-waves scattering parameters definitions
give same results for real characteristic impedances
'''
f0 = rf.Frequency(75.8, npoints=1, unit='GHz')
s_ref = npy.array([[ # random values
[-0.1000 - 0.2000j, -0.3000 + 0.4000j],
[-0.3000 + 0.4000j, 0.5000 - 0.6000j]
]])
ntw = rf.Network(frequency=f0, s=s_ref, z0=50, name='dut')
# renormalize s parameter according one of the definition.
# As characteristic impedances are all real, should be all equal
npy.testing.assert_allclose(ntw.s, s_ref)
npy.testing.assert_allclose(
rf.renormalize_s(ntw.s, 50, 50, s_def='power'), s_ref)
npy.testing.assert_allclose(
rf.renormalize_s(ntw.s, 50, 50, s_def='pseudo'), s_ref)
npy.testing.assert_allclose(
rf.renormalize_s(ntw.s, 50, 50, s_def='traveling'), s_ref)
# also check Z and Y matrices, just in case
z_ref = npy.array([[[18.0000 - 16.0000j, 20.0000 + 40.0000j],
[20.0000 + 40.0000j, 10.0000 - 80.0000j]]])
npy.testing.assert_allclose(ntw.z, z_ref, atol=1e-4)
y_ref = npy.array([[[0.0251 + 0.0023j, 0.0123 - 0.0066j],
[0.0123 - 0.0066j, 0.0052 + 0.0055j]]])
npy.testing.assert_allclose(ntw.y, y_ref, atol=1e-4)
# creating network by specifying s-params definition
ntw_power = rf.Network(frequency=f0, s=s_ref, z0=50, s_def='power')
ntw_pseudo = rf.Network(frequency=f0, s=s_ref, z0=50, s_def='pseudo')
ntw_legacy = rf.Network(frequency=f0,
s=s_ref,
z0=50,
s_def='traveling')
self.assertTrue(ntw_power == ntw_pseudo)
self.assertTrue(ntw_power == ntw_legacy)
def test_network_from_z_or_y(self):
' Construct a network from its z or y parameters '
# test for both real and complex char. impedance
# and for 2 frequencies
z0 = [npy.random.rand(), npy.random.rand() + 1j * npy.random.rand()]
freqs = npy.array([1, 2])
# generate arbitrary complex z and y
z_ref = npy.random.rand(2, 3, 3) + 1j * npy.random.rand(2, 3, 3)
y_ref = npy.random.rand(2, 3, 3) + 1j * npy.random.rand(2, 3, 3)
# create networks from z or y and compare ntw.z to the reference
# check that the conversions work for all s-param definitions
for s_def in S_DEFINITIONS:
ntwk = rf.Network(s_def=s_def)
ntwk.z0 = rf.fix_z0_shape(z0, 2, 3)
ntwk.f = freqs
# test #1: define the network directly from z
ntwk.z = z_ref
npy.testing.assert_allclose(ntwk.z, z_ref)
# test #2: define the network from s, after z -> s (s_def is important)
ntwk.s = rf.z2s(z_ref, z0, s_def=s_def)
npy.testing.assert_allclose(ntwk.z, z_ref)
# test #3: define the network directly from y
ntwk.y = y_ref
npy.testing.assert_allclose(ntwk.y, y_ref)
# test #4: define the network from s, after y -> s (s_def is important)
ntwk.s = rf.y2s(y_ref, z0, s_def=s_def)
npy.testing.assert_allclose(ntwk.y, y_ref)
def test_z0_pure_imaginary(self):
' Test cases where z0 is pure imaginary '
# test that conversion to Z or Y does not give NaN for pure imag z0
for s_def in S_DEFINITIONS:
ntwk = rf.Network(s_def=s_def)
ntwk.z0 = npy.array([50j, -50j])
ntwk.f = npy.array([1000])
ntwk.s = npy.random.rand(1, 2, 2) + npy.random.rand(1, 2, 2) * 1j
self.assertFalse(npy.any(npy.isnan(ntwk.z)))
self.assertFalse(npy.any(npy.isnan(ntwk.y)))
def test_yz(self):
tinyfloat = 1e-12
ntwk = rf.Network()
ntwk.z0 = npy.array([28, 75 + 3j])
ntwk.f = npy.array([1000, 2000])
ntwk.s = rf.z2s(
npy.array([[[1 + 1j, 5, 11], [40, 5, 3], [16, 8, 9 + 8j]],
[[1, 20, 3], [14, 10, 16], [27, 18, -19 - 2j]]]))
self.assertTrue((abs(rf.y2z(ntwk.y) - ntwk.z) < tinyfloat).all())
self.assertTrue(
(abs(rf.y2s(ntwk.y, ntwk.z0) - ntwk.s) < tinyfloat).all())
self.assertTrue((abs(rf.z2y(ntwk.z) - ntwk.y) < tinyfloat).all())
self.assertTrue(
(abs(rf.z2s(ntwk.z, ntwk.z0) - ntwk.s) < tinyfloat).all())
def test_mul(self):
a = rf.N(f=[1, 2], s=[1 + 2j, 3 + 4j], z0=1)
# operating on networks
self.assertTrue(((a * a).s == npy.array([[[-3 + 4j]],
[[-7 + 24j]]])).all())
# operating on numbers
self.assertTrue(((2 * a * 2).s == npy.array([[[4 + 8j]],
[[12 + 16j]]])).all())
# operating on list
self.assertTrue(((a * [1, 2]).s == npy.array([[[1 + 2j]],
[[6 + 8j]]])).all())
self.assertTrue((([1, 2] * a).s == npy.array([[[1 + 2j]],
[[6 + 8j]]])).all())
def test_sub(self):
a = rf.N(f=[1, 2], s=[1 + 2j, 3 + 4j], z0=1)
# operating on networks
self.assertTrue(((a - a).s == npy.array([[[0 + 0j]],
[[0 + 0j]]])).all())
# operating on numbers
self.assertTrue(((a - (2 + 2j)).s == npy.array([[[-1 + 0j]],
[[1 + 2j]]])).all())
# operating on list
self.assertTrue(
((a - [1 + 1j, 2 + 2j]).s == npy.array([[[0 + 1j]],
[[1 + 2j]]])).all())
def test_div(self):
a = rf.N(f=[1, 2], s=[1 + 2j, 3 + 4j], z0=1)
# operating on networks
self.assertTrue(((a / a).s == npy.array([[[1 + 0j]],
[[1 + 0j]]])).all())
# operating on numbers
self.assertTrue(((a / 2.).s == npy.array([[[.5 + 1j]],
[[3 / 2. + 2j]]])).all())
# operating on list
self.assertTrue(((a / [1, 2]).s == npy.array([[[1 + 2j]],
[[3 / 2. + 2j]]])).all())
def test_add(self):
a = rf.N(f=[1, 2], s=[1 + 2j, 3 + 4j], z0=1)
# operating on networks
self.assertTrue(((a + a).s == npy.array([[[2 + 4j]],
[[6 + 8j]]])).all())
# operating on numbers
self.assertTrue(((a + 2 + 2j).s == npy.array([[[3 + 4j]],
[[5 + 6j]]])).all())
# operating on list
self.assertTrue(
((a + [1 + 1j, 2 + 2j]).s == npy.array([[[2 + 3j]],
[[5 + 6j]]])).all())
def test_interpolate(self):
a = rf.N(f=[1, 2], s=[1 + 2j, 3 + 4j], z0=1)
freq = rf.F.from_f(npy.linspace(1, 2, 4), unit='ghz')
b = a.interpolate(freq)
# TODO: numerically test for correct interpolation
def test_interpolate_rational(self):
a = rf.N(f=[1, 2], s=[1 + 2j, 3 + 4j], z0=1)
freq = rf.F.from_f(npy.linspace(1, 2, 4), unit='ghz')
b = a.interpolate(freq, kind='rational')
# TODO: numerically test for correct interpolation
def test_interpolate_self_npoints(self):
a = rf.N(f=[1, 2], s=[1 + 2j, 3 + 4j], z0=1)
a.interpolate_self_npoints(4)
# TODO: numerically test for correct interpolation
def test_interpolate_from_f(self):
a = rf.N(f=[1, 2], s=[1 + 2j, 3 + 4j], z0=1)
a.interpolate_from_f(npy.linspace(1, 2, 4), unit='ghz')
# TODO: numerically test for correct interpolation
def test_slicer(self):
a = rf.Network(f=[1, 2, 4, 5, 6], s=[1, 1, 1, 1, 1], z0=50)
b = a['2-5ghz']
tinyfloat = 1e-12
self.assertTrue(
(abs(b.frequency.f - [2e9, 4e9, 5e9]) < tinyfloat).all())
# Network classifiers
def test_is_reciprocal(self):
a = rf.Network(f=[1, 2], s=[[0, 1, 0], [0, 0, 1], [1, 0, 0]], z0=50)
self.assertFalse(a.is_reciprocal(), 'A circulator is not reciprocal.')
b = rf.Network(f=[1, 2],
s=[[0, 0.5, 0.5], [0.5, 0, 0.5], [0.5, 0.5, 0]],
z0=50)
self.assertTrue(b.is_reciprocal(), 'This power divider is reciprocal.')
return
def test_is_symmetric(self):
# 2-port
a = rf.Network(f=[1, 2], s=[[-1, 0], [0, -1]], z0=50)
self.assertTrue(a.is_symmetric(), 'A short is symmetric.')
self.assertRaises(ValueError, a.is_symmetric,
port_order={1: 2}) # error raised by renumber()
a.s[0, 0, 0] = 1
self.assertFalse(a.is_symmetric(), 'non-symmetrical')
# 3-port
b = rf.Network(f=[1, 2],
s=[[0, 0.5, 0.5], [0.5, 0, 0.5], [0.5, 0.5, 0]],
z0=50)
with self.assertRaises(ValueError) as context:
b.is_symmetric()
self.assertEqual(
str(context.exception),
'test of symmetric is only valid for a 2N-port network')
# 4-port
c = rf.Network(f=[1, 2],
s=[[0, 1j, 1, 0], [1j, 0, 0, 1], [1, 0, 0, 1j],
[0, 1, 1j, 0]],
z0=50)
self.assertTrue(c.is_symmetric(n=2),
'This quadrature hybrid coupler is symmetric.')
self.assertTrue(
c.is_symmetric(n=2, port_order={
0: 1,
1: 2,
2: 3,
3: 0
}),
'This quadrature hybrid coupler is symmetric even after rotation.')
with self.assertRaises(ValueError) as context:
c.is_symmetric(n=3)
self.assertEqual(
str(context.exception),
'specified order n = 3 must be between 1 and N = 2, inclusive')
d = rf.Network(f=[1, 2],
s=[[1, 0, 0, 0], [1, 0, 0, 0], [1, 0, 0, 1],
[0, 1, 0, 1]],
z0=50)
self.assertTrue(
d.is_symmetric(n=1),
'This contrived non-reciprocal device has a line of symmetry.')
self.assertFalse(d.is_symmetric(n=2),
'This device only has first-order line symmetry.')
self.assertFalse(
d.is_symmetric(port_order={
0: 1,
1: 0
}),
'This device is no longer symmetric after reordering ports 1 and 2.'
)
self.assertTrue(
d.is_symmetric(port_order={
0: 1,
1: 0,
2: 3,
3: 2
}),
'This device is symmetric after swapping ports 1 with 2 and 3 with 4.'
)
# 6-port
x = rf.Network(f=[1, 2],
s=[[0, 0, 0, 0, 0, 0], [0, 1, 9, 0, 0, 0],
[0, 0, 2, 0, 0, 0], [0, 0, 0, 2, 0, 0],
[0, 0, 0, 9, 1, 0], [0, 0, 0, 0, 0, 0]],
z0=50)
self.assertFalse(x.is_symmetric(n=3))
self.assertFalse(x.is_symmetric(n=2))
self.assertTrue(x.is_symmetric(n=1))
self.assertTrue(
x.is_symmetric(n=1, port_order={
-3: -1,
-1: -3,
0: 2,
2: 0
}))
# 8-port
s8p_diag = [1j, -1j, -1j, 1j, 1j, -1j, -1j, 1j]
s8p_mat = npy.identity(8, dtype=complex)
for row in range(8):
s8p_mat[row, :] *= s8p_diag[row]
y = rf.Network(f=[1, 2], s=s8p_mat, z0=50)
self.assertTrue(y.is_symmetric())
self.assertTrue(y.is_symmetric(n=2))
self.assertFalse(y.is_symmetric(n=4))
return
def test_is_passive(self):
a = rf.Network(f=[1, 2],
s=[[0, 0.5, 0.5], [0.5, 0, 0.5], [0.5, 0.5, 0]],
z0=50)
self.assertTrue(a.is_passive(), 'This power divider is passive.')
b = rf.Network(f=[1, 2], s=[[0, 0], [10, 0]], z0=50)
self.assertFalse(b.is_passive(),
'A unilateral amplifier is not passive.')
return
def test_is_lossless(self):
a = rf.Network(f=[1, 2],
s=[[0, 0.5, 0.5], [0.5, 0, 0.5], [0.5, 0.5, 0]],
z0=50)
self.assertFalse(a.is_lossless(),
'A resistive power divider is lossy.')
b = rf.Network(f=[1, 2],
s=[[0, -1j / npy.sqrt(2), -1j / npy.sqrt(2)],
[-1j / npy.sqrt(2), 1. / 2, -1. / 2],
[-1j / npy.sqrt(2), -1. / 2, 1. / 2]],
z0=50)
self.assertTrue(b.is_lossless(),
'This unmatched power divider is lossless.')
return
def test_noise(self):
a = rf.Network(os.path.join(self.test_dir, 'ntwk_noise.s2p'))
nf = 10**(0.05)
self.assertTrue(a.noisy)
self.assertTrue(
abs(a.nfmin[0] - nf) < 1.e-6,
'noise figure does not match original spec')
self.assertTrue(
abs(a.z_opt[0] - 50.) < 1.e-6,
'optimal resistance does not match original spec')
self.assertTrue(
abs(a.rn[0] - 0.1159 * 50.) < 1.e-6,
'equivalent resistance does not match original spec')
self.assertTrue(
npy.all(abs(a.g_opt) < 1.e-6),
'calculated optimal reflection coefficient does not match original coefficients'
)
b = rf.Network(f=[1, 2], s=[[[0, 1], [1, 0]], [[0, 1], [1, 0]]],
z0=50).interpolate(a.frequency)
with self.assertRaises(ValueError) as context:
b.n
with self.assertRaises(ValueError) as context:
b.f_noise
self.assertEqual(str(context.exception), 'network does not have noise')
c = a**b
self.assertTrue(a.noisy)
self.assertTrue(
abs(c.nfmin[0] - nf) < 1.e-6,
'noise figure does not match original spec')
self.assertTrue(
abs(c.z_opt[0] - 50.) < 1.e-6,
'optimal resistance does not match original spec')
self.assertTrue(
abs(c.rn[0] - 0.1159 * 50.) < 1.e-6,
'equivalent resistance does not match original spec')
d = b**a
self.assertTrue(d.noisy)
self.assertTrue(
abs(d.nfmin[0] - nf) < 1.e-6,
'noise figure does not match original spec')
self.assertTrue(
abs(d.z_opt[0] - 50.) < 1.e-6,
'optimal resistance does not match original spec')
self.assertTrue(
abs(d.rn[0] - 0.1159 * 50.) < 1.e-6,
'equivalent resistance does not match original spec')
e = a**a
self.assertTrue(
abs(e.nfmin[0] - (nf + (nf - 1) / (10**2))) < 1.e-6,
'noise figure does not match Friis formula')
self.assertTrue(a.noisy)
self.assertTrue(
abs(a.nfmin[0] - nf) < 1.e-6, 'noise figure was altered')
self.assertTrue(
abs(a.z_opt[0] - 50.) < 1.e-6, 'optimal resistance was altered')
self.assertTrue(
abs(a.rn[0] - 0.1159 * 50.) < 1.e-6,
'equivalent resistance was altered')
tem = DistributedCircuit(z0=50)
inductor = tem.inductor(1e-9).interpolate(a.frequency)
f = inductor**a
expected_zopt = 50 - 2j * npy.pi * 1e+9 * 1e-9
self.assertTrue(
abs(f.z_opt[0] - expected_zopt) < 1.e-6,
'optimal resistance was not 50 ohms - inductor')
return
def test_noise_deembed(self):
f1_ = [75.5, 75.5]
f2_ = [75.5, 75.6]
npt_ = [1, 2] # single freq and multifreq
for f1, f2, npt in zip(f1_, f2_, npt_):
freq = rf.Frequency(f1, f2, npt, 'ghz')
ntwk4_n = rf.Network(os.path.join(self.test_dir, 'ntwk4_n.s2p'),
f_unit='GHz').interpolate(freq)
ntwk4 = rf.Network(os.path.join(self.test_dir, 'ntwk4.s2p'),
f_unit='GHz').interpolate(freq)
thru = rf.Network(os.path.join(self.test_dir, 'thru.s2p'),
f_unit='GHz').interpolate(freq)
ntwk4_thru = ntwk4**thru
ntwk4_thru.name = 'ntwk4_thru'
retrieve_thru = ntwk4.inv**ntwk4_thru
retrieve_thru.name = 'retrieve_thru'
self.assertEqual(retrieve_thru, thru)
self.assertTrue(ntwk4_thru.noisy)
self.assertTrue(retrieve_thru.noisy)
self.assertTrue(
(abs(thru.nfmin - retrieve_thru.nfmin) < 1.e-6).all(),
'nf not retrieved by noise deembed')
self.assertTrue((abs(thru.rn - retrieve_thru.rn) < 1.e-6).all(),
'rn not retrieved by noise deembed')
self.assertTrue(
(abs(thru.z_opt - retrieve_thru.z_opt) < 1.e-6).all(),
'noise figure does not match original spec')
ntwk4_n_thru = ntwk4_n**thru
ntwk4_n_thru.name = 'ntwk4_n_thru'
retrieve_n_thru = ntwk4_n.inv**ntwk4_n_thru
retrieve_n_thru.name = 'retrieve_n_thru'
self.assertTrue(ntwk4_n_thru.noisy)
self.assertEqual(retrieve_n_thru, thru)
self.assertTrue(ntwk4_n_thru.noisy)
self.assertTrue(retrieve_n_thru.noisy)
self.assertTrue(
(abs(thru.nfmin - retrieve_n_thru.nfmin) < 1.e-6).all(),
'nf not retrieved by noise deembed')
self.assertTrue((abs(thru.rn - retrieve_n_thru.rn) < 1.e-6).all(),
'rn not retrieved by noise deembed')
self.assertTrue(
(abs(thru.z_opt - retrieve_n_thru.z_opt) < 1.e-6).all(),
'noise figure does not match original spec')
tuner, x, y, g = tuner_constellation()
newnetw = thru.copy()
nfmin_set = 4.5
gamma_opt_set = complex(.7, -0.2)
rn_set = 1
newnetw.set_noise_a(thru.noise_freq,
nfmin_db=nfmin_set,
gamma_opt=gamma_opt_set,
rn=rn_set)
z = newnetw.nfdb_gs(g)[:, 0]
freq = thru.noise_freq.f[0]
gamma_opt_rb, nfmin_rb = plot_contour(freq,
x,
y,
z,
min0max1=0,
graph=False)
self.assertTrue(
abs(nfmin_set - nfmin_rb) < 1.e-2,
'nf not retrieved by noise deembed')
self.assertTrue(
abs(gamma_opt_rb.s[0, 0, 0] - gamma_opt_set) < 1.e-1,
'nf not retrieved by noise deembed')
def test_se2gmm2se_mag(self):
ntwk4 = rf.Network(
os.path.join(self.test_dir, 'cst_example_4ports.s4p'))
ntwk4t = deepcopy(ntwk4)
ntwk4t.se2gmm(p=2)
ntwk4t.gmm2se(p=2)
self.assertTrue(
npy.allclose(abs(ntwk4.s), abs(ntwk4t.s), rtol=1E-7, atol=0))
# phase testing does not pass - see #367
#self.assertTrue(npy.allclose(npy.angle(ntwk4.s), npy.angle(ntwk4t.s), rtol=1E-7, atol=1E-10))
def test_s_active(self):
'''
Test the active s-parameters of a 2-ports network
'''
s_ref = self.ntwk1.s
# s_act should be equal to s11 if a = [1,0]
npy.testing.assert_array_almost_equal(
rf.s2s_active(s_ref, [1, 0])[:, 0], s_ref[:, 0, 0])
# s_act should be equal to s22 if a = [0,1]
npy.testing.assert_array_almost_equal(
rf.s2s_active(s_ref, [0, 1])[:, 1], s_ref[:, 1, 1])
# s_act should be equal to s11 if a = [1,0]
npy.testing.assert_array_almost_equal(
self.ntwk1.s_active([1, 0])[:, 0], s_ref[:, 0, 0])
# s_act should be equal to s22 if a = [0,1]
npy.testing.assert_array_almost_equal(
self.ntwk1.s_active([0, 1])[:, 1], s_ref[:, 1, 1])
def test_vswr_active(self):
'''
Test the active vswr-parameters of a 2-ports network
'''
s_ref = self.ntwk1.s
vswr_ref = self.ntwk1.s_vswr
# vswr_act should be equal to vswr11 if a = [1,0]
npy.testing.assert_array_almost_equal(
rf.s2vswr_active(s_ref, [1, 0])[:, 0], vswr_ref[:, 0, 0])
# vswr_act should be equal to vswr22 if a = [0,1]
npy.testing.assert_array_almost_equal(
rf.s2vswr_active(s_ref, [0, 1])[:, 1], vswr_ref[:, 1, 1])
# vswr_act should be equal to vswr11 if a = [1,0]
npy.testing.assert_array_almost_equal(
self.ntwk1.vswr_active([1, 0])[:, 0], vswr_ref[:, 0, 0])
# vswr_act should be equal to vswr22 if a = [0,1]
npy.testing.assert_array_almost_equal(
self.ntwk1.vswr_active([0, 1])[:, 1], vswr_ref[:, 1, 1])
def test_subnetwork(self):
''' Test subnetwork creation and recombination '''
tee = rf.data.tee # 3 port Network
# modify the z0 to dummy values just to check it works for any z0
tee.z0 = npy.random.rand(3) + 1j * npy.random.rand(3)
# Using rf.subnetwork()
# 2 port Networks as if one measures the tee with a 2 ports VNA
tee12 = rf.subnetwork(
tee, [0, 1]) # 2 port Network from ports 1 & 2, port 3 matched
tee23 = rf.subnetwork(
tee, [1, 2]) # 2 port Network from ports 2 & 3, port 1 matched
tee13 = rf.subnetwork(
tee, [0, 2]) # 2 port Network from ports 1 & 3, port 2 matched
# recreate the original 3 ports Network from the thee 2-port sub-Networks
ntw_list = [tee12, tee23, tee13]
tee2 = rf.n_twoports_2_nport(ntw_list, nports=3)
self.assertTrue(tee2 == tee)
# Same from the subnetwork() method.
tee12 = tee.subnetwork([0, 1])
tee23 = tee.subnetwork([1, 2])
tee13 = tee.subnetwork([0, 2])
ntw_list = [tee12, tee23, tee13]
tee2 = rf.n_twoports_2_nport(ntw_list, nports=3)
self.assertTrue(tee2 == tee)
def test_qucs_network(self):
"""
Test against the Qucs project results
"""
if self.verbose:
fig, axs = plt.subplots(2, 2, figsize = (8,6))
fig.suptitle('qucs/skrf')
fig2, axs2 = plt.subplots(2, 2, figsize = (8,6))
fig2.suptitle('qucs/skrf residuals')
fig3, ax3 = plt.subplots(1, 1, figsize = (8,3))
limit = 2e-3
for ref in self.ref_qucs:
cpw = CPW(frequency = ref['n'].frequency, z0 = 50.,
w = ref['w'], s = ref['s'], t = ref['t'],
h = ref['h'],
has_metal_backside = ref['has_metal_backside'],
ep_r = self.ep_r, rho = self.rho,
tand = self.tand,
compatibility_mode = 'qucs',
diel = 'frequencyinvariant')
line = cpw.line(d=self.l, unit='m', embed = True, z0=cpw.Z0)
line.name = '`Media.CPW` skrf,qucs'
# residuals
res = line - ref['n']
# test if within limit
self.assertTrue(npy.all(npy.abs(res.s) < limit))
if self.verbose:
ax3.plot(npy.abs(res.s[0,0]))
ax3.plot(npy.abs(res.s[0,1]))
ax3.plot(npy.abs(res.s[1,0]))
ax3.plot(npy.abs(res.s[1,1]))
res = line / ref['n']
res.name = 'residuals ' + ref['n'].name
line.plot_s_db(0, 0, ax = axs[0, 0], color = ref['color'],
linestyle = 'none', marker = 'x')
ref['n'].plot_s_db(0, 0, ax = axs[0, 0], color = ref['color'])
res.plot_s_db(0, 0, ax = axs2[0, 0], linestyle = 'dashed',
color = ref['color'])
line.plot_s_deg(0, 0, ax = axs[0, 1], color = ref['color'],
linestyle = 'none', marker = 'x')
ref['n'].plot_s_deg(0, 0, ax = axs[0, 1], color = ref['color'])
res.plot_s_deg(0, 0, ax = axs2[0, 1], linestyle = 'dashed',
color = ref['color'])
line.plot_s_db(1, 0, ax = axs[1, 0], color = ref['color'],
linestyle = 'none', marker = 'x')
ref['n'].plot_s_db(1, 0, ax = axs[1, 0], color = ref['color'])
res.plot_s_db(1, 0, ax = axs2[1, 0], linestyle = 'dashed',
color = ref['color'])
line.plot_s_deg(1, 0, ax = axs[1, 1], color = ref['color'],
linestyle = 'none', marker = 'x')
ref['n'].plot_s_deg(1, 0, ax = axs[1, 1], color = ref['color'])
res.plot_s_deg(1, 0, ax = axs2[1, 1], linestyle = 'dashed',
color = ref['color'])
if self.verbose:
axs[1, 0].legend(prop={'size': 6})
axs[0, 0].get_legend().remove()
axs[0, 1].get_legend().remove()
axs[1, 1].get_legend().remove()
fig.tight_layout()
axs2[1, 0].legend(prop={'size': 6})
axs2[0, 0].get_legend().remove()
axs2[0, 1].get_legend().remove()
axs2[1, 1].get_legend().remove()
fig2.tight_layout()
def setUp(self):
self.data_dir_qucs = os.path.join(
os.path.dirname(os.path.abspath(__file__)),
'qucs_prj')
self.data_dir_ads = os.path.join(
os.path.dirname(os.path.abspath(__file__)),
'ads')
fname = os.path.join(self.data_dir_qucs, 'cpw.s2p')
self.qucs_ntwk = rf.Network(fname)
# create various examples
self.freq = rf.Frequency(start=1, stop=20, npoints=21, unit='GHz')
# infinite quarz substrate, infinitely thin metal
self.cpw1 = CPW(frequency=self.freq, w=40e-6, s=20e-6, h = 100e-3, ep_r=3.78)
# infinite GaAs substrate, infinitely thin metal
self.cpw2 = CPW(frequency=self.freq, w=75e-6, s=50e-6, h = 100e-3, ep_r=12.9)
# coplanar on FR-4 printed circuit board without conductor backing
# with zero thickness strip
self.cpw4 = CPW(frequency = self.freq, w = 3.0e-3, s = 0.3e-3,
t = None, ep_r = 4.5, rho = None, z0 = 50.)
self.cpw5 = CPW(frequency = self.freq, w = 3.0e-3, s = 0.3e-3,
t = 0., ep_r = 4.5, rho = None, z0 = 50.)
# more newtorks to test against Qucs with air or metal backing
self.ref_qucs = [
{'has_metal_backside': True, 'w': 1.6e-3, 's': 0.3e-3, 't': 35e-6,
'h': 1.55e-3, 'color': 'b',
'n': rf.Network(os.path.join(self.data_dir_qucs,
'cpw,t=35um,w=1.6mm,s=0.3mm,l=25mm,backside=metal.s2p'))},
{'has_metal_backside': False, 'w': 3.0e-3, 's': 0.3e-3, 't': 35e-6,
'h': 1.55e-3, 'color': 'g',
'n': rf.Network(os.path.join(self.data_dir_qucs,
'cpw,t=35um,w=3mm,s=0.3mm,l=25mm,backside=air.s2p'))},
{'has_metal_backside': False, 'w': 3.0e-3, 's': 0.3e-3, 't': 0,
'h': 100e-3, 'color': 'r',
'n': rf.Network(os.path.join(self.data_dir_qucs,
'cpw,t=0,h=100mm,w=3mm,s=0.3mm,l=25mm,backside=air.s2p'))},
]
self.ref_ads = [
{'has_metal_backside': False, 'w': 3.0e-3, 's': 0.3e-3, 't': 0.,
'h': 1.55e-3, 'color': 'C0',
'n': rf.Network(os.path.join(self.data_dir_ads,
'cpw,t=0um.s2p'))},
{'has_metal_backside': True, 'w': 1.6e-3, 's': 0.3e-3, 't': 0.,
'h': 1.55e-3, 'color': 'C1',
'n': rf.Network(os.path.join(self.data_dir_ads,
'cpwg,t=0um.s2p'))},
]
# these would fail comparison because ADS use another strip thickness
# correction. Kept for reference in case of future work.
self.ref_ads_failling = [
{'has_metal_backside': False, 'w': 3.0e-3, 's': 0.3e-3, 't': 35e-6,
'h': 1.55e-3, 'color': 'C2',
'n': rf.Network(os.path.join(self.data_dir_ads,
'cpw,t=35um.s2p'))},
{'has_metal_backside': True, 'w': 1.6e-3, 's': 0.3e-3, 't': 35e-6,
'h': 1.55e-3, 'color': 'C3',
'n': rf.Network(os.path.join(self.data_dir_ads,
'cpwg,t=35um.s2p'))},
]
# default parameter set for tests
self.verbose = False # output comparison plots if True
self.l = 25e-3
self.ep_r = 4.5
self.tand = 0.018
self.rho = 1.7e-8
class NetworkTestCase(unittest.TestCase):
"""
Network class operation test case.
The following is true, as tested by lihan in ADS,
test3 == test1 ** test2
To test for 2N-port deembeding Meas, Fix and DUT are created such as:
::
Meas == Fix ** DUT
Meas Fix DUT
+---------+ +---------+ +---------+
-|0 4|- -|0 4|---|0 4|-
-|1 5|- = -|1 5|---|1 5|-
-|2 6|- -|2 6|---|2 6|-
-|3 7|- -|3 7|---|3 7|-
+---------+ +---------+ +---------+
Note:
-----
due to the complexity of inv computations, there will be an unavoidable
precision loss. thus Fix.inv ** Meas will show a small difference with DUT.
"""
def setUp(self):
"""
this also tests the ability to read touchstone files
without an error
"""
setup_pylab()
self.test_dir = os.path.dirname(os.path.abspath(__file__))+'/'
self.ntwk1 = rf.Network(os.path.join(self.test_dir, 'ntwk1.s2p'))
self.ntwk2 = rf.Network(os.path.join(self.test_dir, 'ntwk2.s2p'))
self.ntwk3 = rf.Network(os.path.join(self.test_dir, 'ntwk3.s2p'))
self.freq = rf.Frequency(75,110,101,'ghz')
self.cpw = CPW(self.freq, w=10e-6, s=5e-6, ep_r=10.6)
l1 = self.cpw.line(0.20, 'm', z0=50)
l2 = self.cpw.line(0.07, 'm', z0=50)
l3 = self.cpw.line(0.47, 'm', z0=50)
self.Fix = rf.concat_ports([l1, l1, l1, l1])
self.DUT = rf.concat_ports([l2, l2, l2, l2])
self.Meas = rf.concat_ports([l3, l3, l3, l3])
def test_timedomain(self):
t = self.ntwk1.s11.s_time
s = self.ntwk1.s11.s
self.assertTrue(len(t)== len(s))
def test_time_gate(self):
ntwk = self.ntwk1
gated = self.ntwk1.s11.time_gate(0,.2)
self.assertTrue(len(gated)== len(ntwk))
def test_time_transform(self):
spb = (4, 5)
data_rate = 5e9
num_taps = (100, 101)
for i in range(2):
tps = 1. / spb[i] / data_rate
num_points = spb[i] * num_taps[i]
# Frequency terms should NOT contain Nyquist frequency if number of points is odd
inc_nyq = True if num_points % 2 == 0 else False
freq = npy.linspace(0, 1. / 2 / tps, num_points // 2 + 1, endpoint=inc_nyq)
dut = self.ntwk1.copy()
freq_valid = freq[npy.logical_and(freq >= dut.f[0], freq <= dut.f[-1])]
dut.interpolate_self(rf.Frequency.from_f(freq_valid, unit='hz'))
dut_dc = dut.extrapolate_to_dc()
t, y = dut_dc.s21.impulse_response(n=num_points)
self.assertEqual(len(t), num_points)
self.assertEqual(len(y), num_points)
self.assertTrue(npy.isclose(t[1] - t[0], tps))
t, y = dut_dc.s21.step_response(n=num_points)
self.assertEqual(len(t), num_points)
self.assertEqual(len(y), num_points)
self.assertTrue(npy.isclose(t[1] - t[0], tps))
def test_impulse_response_dirac(self):
"""
Test if the impulse response of a perfect transmission line is pure Dirac
"""
f_points = 10
freq = rf.Frequency.from_f(npy.arange(f_points), unit='Hz')
s = npy.ones(10)
netw = rf.Network(frequency=freq, s=s)
n_lst = npy.arange(-1,2) + 2 * (f_points) - 2
for n in n_lst:
t,y = netw.impulse_response('boxcar', n=n)
y_true = npy.zeros_like(y)
y_true[t == 0] = 1
npy.testing.assert_almost_equal(y, y_true)
def test_time_transform_nonlinear_f(self):
netw_nonlinear_f = rf.Network(os.path.join(self.test_dir, 'ntwk_arbitrary_frequency.s2p'))
with self.assertRaises(NotImplementedError):
netw_nonlinear_f.s11.step_response()
def test_time_transform(self):
with self.assertWarns(RuntimeWarning):
self.ntwk1.s11.step_response()
def test_time_transform_multiport(self):
dut_dc = self.ntwk1.extrapolate_to_dc()
y1 = npy.zeros((1000, dut_dc.nports, dut_dc.nports))
for (i,j) in dut_dc.port_tuples:
oneport = getattr(dut_dc, f's{i+1}{j+1}')
t1, y1[:,i,j] = oneport.step_response(n=1000)
t2, y2 = dut_dc.step_response(n=1000)
npy.testing.assert_almost_equal(t1, t2)
npy.testing.assert_almost_equal(y1, y2)
def test_time_transform_squeeze(self):
dut_dc = self.ntwk1.extrapolate_to_dc()
assert dut_dc.s11.step_response()[1].ndim == 1
assert dut_dc.s11.step_response(squeeze=False)[1].ndim == 3
assert dut_dc.step_response()[1].ndim == 3
assert dut_dc.step_response(squeeze=False)[1].ndim == 3
def test_constructor_empty(self):
rf.Network()
def test_constructor_from_values(self):
rf.Network(f=[1,2],s=[1,2],z0=[1,2] )
def test_constructor_from_touchstone(self):
rf.Network(os.path.join(self.test_dir, 'ntwk1.s2p'))
def test_constructor_from_touchstone_special_encoding(self):
" Test creating Network from Touchstone file with various file encodings."
filename_latin1 = os.path.join(self.test_dir, '../io/tests/test_encoding_ISO-8859-1.s2p')
filename_utf8 = os.path.join(self.test_dir, '../io/tests/test_encoding_UTF-8-SIG.s2p')
ntwk1 = rf.Network(filename_latin1)
ntwk1_ = rf.Network(filename_latin1, encoding='latin_1')
self.assertEqual(ntwk1.comments, ntwk1_.comments)
ntwk2 = rf.Network(filename_utf8, encoding='utf_8_sig')
self.assertEqual(ntwk1.comments, ntwk2.comments)
def test_constructor_from_hfss_touchstone(self):
# HFSS can provide the port characteristic impedances in its generated touchstone file.
# Check if reading a HFSS touchstone file with non-50Ohm impedances
ntwk_hfss = rf.Network(os.path.join(self.test_dir, 'hfss_threeport_DB.s3p'))
self.assertFalse(npy.isclose(ntwk_hfss.z0[0,0], 50))
def test_constructor_from_pathlib(self):
rf.Network(Path(self.test_dir) / 'ntwk1.ntwk')
def test_constructor_from_pickle(self):
rf.Network(os.path.join(self.test_dir, 'ntwk1.ntwk'))
def test_constructor_from_fid_touchstone(self):
filename= os.path.join(self.test_dir, 'ntwk1.s2p')
with open(filename,'rb') as fid:
rf.Network(fid)
with open(filename) as fid:
rf.Network(fid)
def test_constructor_from_stringio(self):
filename= os.path.join(self.test_dir, 'ntwk1.s2p')
with open(filename) as fid:
data = fid.read()
sio = io.StringIO(data)
sio.name = os.path.basename(filename) # hack a bug to touchstone reader
rf.Network(sio)
filename = os.path.join(self.test_dir, 'hfss_oneport.s1p')
with open(filename) as fid:
data = fid.read()
sio = io.StringIO(data)
sio.name = os.path.basename(filename) # hack a bug to touchstone reader
rf.Network(sio)
def test_zipped_touchstone(self):
zippath = os.path.join(self.test_dir, 'ntwks.zip')
fname = 'ntwk1.s2p'
rf.Network.zipped_touchstone(fname, zipfile.ZipFile(zippath))
def test_open_saved_touchstone(self):
self.ntwk1.write_touchstone('ntwk1Saved',dir=self.test_dir)
ntwk1Saved = rf.Network(os.path.join(self.test_dir, 'ntwk1Saved.s2p'))
self.assertEqual(self.ntwk1, ntwk1Saved)
os.remove(os.path.join(self.test_dir, 'ntwk1Saved.s2p'))
def test_pickling(self):
original_ntwk = self.ntwk1
with tempfile.NamedTemporaryFile(dir=self.test_dir, suffix='ntwk') as fid:
pickle.dump(original_ntwk, fid, protocol=2) # Default Python2: 0, Python3: 3
fid.seek(0)
unpickled = pickle.load(fid)
self.assertEqual(original_ntwk, unpickled)
def test_stitch(self):
tmp = self.ntwk1.copy()
tmp.f = tmp.f+ tmp.f[0]
c = rf.stitch(self.ntwk1, tmp)
def test_cascade(self):
self.assertEqual(self.ntwk1 ** self.ntwk2, self.ntwk3)
self.assertEqual(self.Fix ** self.DUT ** self.Fix.flipped(), self.Meas)
def test_connect(self):
self.assertEqual(rf.connect(self.ntwk1, 1, self.ntwk2, 0) , \
self.ntwk3)
xformer = rf.Network()
xformer.frequency=(1,)
xformer.s = ((0,1),(1,0)) # connects thru
xformer.z0 = (50,25) # transforms 50 ohm to 25 ohm
c = rf.connect(xformer,0,xformer,1) # connect 50 ohm port to 25 ohm port
self.assertTrue(npy.all(npy.abs(c.s-rf.impedance_mismatch(50, 25)) < 1e-6))
def test_connect_nport_2port(self):
freq = rf.Frequency(1, 10, npoints=10, unit='GHz')
# create a line which can be connected to each port
med = rf.DefinedGammaZ0(freq)
line = med.line(1, unit='m')
line.z0 = [10, 20]
for nport_portnum in [3,4,5,6,7,8]:
# create a Nport network with port impedance i at port i
nport = rf.Network()
nport.frequency = freq
nport.s = npy.zeros((10, nport_portnum, nport_portnum))
nport.z0 = npy.arange(nport_portnum)
# Connect the line to each port and check for port impedance
for port in range(nport_portnum):
nport_line = rf.connect(nport, port, line, 0)
z0_expected = nport.z0
z0_expected[:,port] = line.z0[:,1]
npy.testing.assert_allclose(
nport_line.z0,
z0_expected
)
def test_connect_no_frequency(self):
""" Connecting 2 networks defined without frequency returns Error
"""
# try to connect two networks defined without their frequency properties
s = npy.random.rand(10, 2, 2)
ntwk1 = rf.Network(s=s)
ntwk2 = rf.Network(s=s)
with self.assertRaises(ValueError):
ntwk1**ntwk2
def test_delay(self):
ntwk1_delayed = self.ntwk1.delay(1,'ns',port=0)
self.assertTrue(
npy.all(
self.ntwk1.group_delay[:,:,:]
-ntwk1_delayed.group_delay[:,:,:]
-npy.array(
[[-1.e-09+0.j, -5.e-10+0.j],
[-5.e-10+0.j, 0.e+00+0.j]]
) < 1e-9
)
)
ntwk2_delayed = self.ntwk2.delay(1,'ps',port=1)
self.assertTrue(
npy.all(
self.ntwk2.group_delay[:,:,:]
-ntwk2_delayed.group_delay[:,:,:]
-npy.array(
[[ 0.e+00+0.j, -5.e-13+0.j],
[-5.e-13+0.j, -1.e-12+0.j]]
) < 1e-9
)
)
def test_connect_multiports(self):
a = rf.Network()
a.frequency=(1,)
a.s = npy.arange(16).reshape(4,4)
a.z0 = npy.arange(4) + 1 # Z0 should never be zero
b = rf.Network()
b.frequency=(1,)
b.s = npy.arange(16).reshape(4,4)
b.z0 = npy.arange(4)+10
c=rf.connect(a,2,b,0,2)
self.assertTrue((c.z0==[1,2,12,13]).all())
d=rf.connect(a,0,b,0,3)
self.assertTrue((d.z0==[4,13]).all())
@pytest.mark.skip(reason="not supporting this function currently ")
def test_connect_fast(self):
self.assertEqual(rf.connect_fast(self.ntwk1, 1, self.ntwk2, 0) , \
self.ntwk3)
xformer = rf.Network()
xformer.frequency=(1,)
xformer.s = ((0,1),(1,0)) # connects thru
xformer.z0 = (50,25) # transforms 50 ohm to 25 ohm
c = rf.connect_fast(xformer,0,xformer,1) # connect 50 ohm port to 25 ohm port
self.assertTrue(npy.all(npy.abs(c.s-rf.impedance_mismatch(50, 25)) < 1e-6))
def test_flip(self):
self.assertEqual(rf.connect(self.ntwk1, 1, self.ntwk2, 0) , \
self.ntwk3)
gain = rf.Network()
gain.frequency=(1,)
gain.s = ((0,2),(0.5,0)) # connects thru with gain of 2.0
gain.z0 = (37,82)
flipped = gain.copy()
flipped.flip()
c = rf.connect(gain,1,flipped,0)
self.assertTrue(npy.all(npy.abs(c.s - npy.array([[0,1],[1,0]])) < 1e-6))
def test_de_embed_by_inv(self):
self.assertEqual(self.ntwk1.inv ** self.ntwk3, self.ntwk2)
self.assertEqual(self.ntwk3 ** self.ntwk2.inv, self.ntwk1)
self.assertEqual(self.Fix.inv ** self.Meas ** self.Fix.flipped().inv,
self.DUT)
def test_plot_one_port_db(self):
self.ntwk1.plot_s_db(0,0)
def test_plot_one_port_deg(self):
self.ntwk1.plot_s_deg(0,0)
def test_plot_one_port_smith(self):
self.ntwk1.plot_s_smith(0,0)
def test_plot_two_port_db(self):
self.ntwk1.plot_s_db()
def test_plot_two_port_deg(self):
self.ntwk1.plot_s_deg()
def test_plot_two_port_smith(self):
self.ntwk1.plot_s_smith()
def test_zy_singularities(self):
open = rf.N(f=[1], s=[1], z0=[50])
short = rf.N(f=[1], s=[-1], z0=[50])
react = rf.N(f=[1],s=[[0,1],[1,0]],z0=50)
z = open.z
y = short.y
a = react.y
def test_conversions(self):
#Converting to other format and back to S-parameters should return the original network
s_random = npy.random.uniform(-10, 10, (self.freq.npoints, 2, 2)) + 1j * npy.random.uniform(-10, 10, (self.freq.npoints, 2, 2))
ntwk_random = rf.Network(s=s_random, frequency=self.freq)
for test_z0 in (50, 10, 90+10j, 4-100j):
for test_ntwk in (self.ntwk1, self.ntwk2, self.ntwk3, ntwk_random):
ntwk = rf.Network(s=test_ntwk.s, f=test_ntwk.f, z0=test_z0)
npy.testing.assert_allclose(rf.a2s(rf.s2a(ntwk.s, test_z0), test_z0), ntwk.s)
npy.testing.assert_allclose(rf.z2s(rf.s2z(ntwk.s, test_z0), test_z0), ntwk.s)
npy.testing.assert_allclose(rf.y2s(rf.s2y(ntwk.s, test_z0), test_z0), ntwk.s)
npy.testing.assert_allclose(rf.h2s(rf.s2h(ntwk.s, test_z0), test_z0), ntwk.s)
npy.testing.assert_allclose(rf.t2s(rf.s2t(ntwk.s)), ntwk.s)
npy.testing.assert_allclose(rf.t2s(rf.s2t(self.Fix.s)), self.Fix.s)
def test_setters(self):
s_random = npy.random.uniform(-10, 10, (self.freq.npoints, 2, 2)) + 1j * npy.random.uniform(-10, 10, (self.freq.npoints, 2, 2))
ntwk = rf.Network(s=s_random, frequency=self.freq)
ntwk.z0 = npy.random.uniform(1, 100, len(ntwk.z0)) + 1j*npy.random.uniform(-100, 100, len(ntwk.z0))
ntwk.s = ntwk.s
npy.testing.assert_allclose(ntwk.s, s_random)
ntwk.a = ntwk.a
npy.testing.assert_allclose(ntwk.s, s_random)
ntwk.z = ntwk.z
npy.testing.assert_allclose(ntwk.s, s_random)
ntwk.y = ntwk.y
npy.testing.assert_allclose(ntwk.s, s_random)
ntwk.t = ntwk.t
npy.testing.assert_allclose(ntwk.s, s_random)
ntwk.h = ntwk.h
npy.testing.assert_allclose(ntwk.s, s_random)
def test_sparam_conversion_with_complex_char_impedance(self):
"""
Renormalize a 2-port network wrt to complex characteristic impedances
using power-waves definition of s-param
Example based on scikit-rf issue #313
"""
f0 = rf.Frequency(75.8, npoints=1, unit='GHz')
s0 = npy.array([
[-0.194 - 0.228j, -0.721 + 0.160j],
[-0.721 + 0.160j, +0.071 - 0.204j]])
ntw = rf.Network(frequency=f0, s=s0, z0=50, name='dut')
# complex characteristic impedance to renormalize to
zdut = 100 + 10j
# reference solutions obtained from ANSYS Circuit or ADS (same res)
# case 1: z0=[50, zdut]
s_ref = npy.array([[
[-0.01629813-0.29764199j, -0.6726785 +0.24747539j],
[-0.6726785 +0.24747539j, -0.30104687-0.10693578j]]])
npy.testing.assert_allclose(rf.z2s(ntw.z, z0=[50, zdut]), s_ref)
npy.testing.assert_allclose(rf.renormalize_s(ntw.s, [50,50], [50,zdut]), s_ref)
# case 2: z0=[zdut, zdut]
s_ref = npy.array([[
[-0.402829859501534 - 0.165007172677339j,-0.586542065592524 + 0.336098534178339j],
[-0.586542065592524 + 0.336098534178339j,-0.164707376748782 - 0.21617153431756j]]])
npy.testing.assert_allclose(rf.z2s(ntw.z, z0=[zdut, zdut]), s_ref)
npy.testing.assert_allclose(rf.renormalize_s(ntw.s, [50,50], [zdut,zdut]), s_ref)
# Comparing Z and Y matrices from reference ones (from ADS)
# Z or Y matrices do not depend of characteristic impedances.
# Precision is 1e-4 due to rounded results in ADS export files
z_ref = npy.array([[
[34.1507 -65.6786j, -37.7994 +73.7669j],
[-37.7994 +73.7669j, 55.2001 -86.8618j]]])
npy.testing.assert_allclose(ntw.z, z_ref, atol=1e-4)
y_ref = npy.array([[
[0.0926 +0.0368j, 0.0770 +0.0226j],
[0.0770 +0.0226j, 0.0686 +0.0206j]]])
npy.testing.assert_allclose(ntw.y, y_ref, atol=1e-4)
def test_sparam_conversion_vs_sdefinition(self):
"""
Check that power-wave or pseudo-waves scattering parameters definitions
give same results for real characteristic impedances
"""
f0 = rf.Frequency(75.8, npoints=1, unit='GHz')
s_ref = npy.array([[ # random values
[-0.1000 -0.2000j, -0.3000 +0.4000j],
[-0.3000 +0.4000j, 0.5000 -0.6000j]]])
ntw = rf.Network(frequency=f0, s=s_ref, z0=50, name='dut')
# renormalize s parameter according one of the definition.
# As characteristic impedances are all real, should be all equal
npy.testing.assert_allclose(ntw.s, s_ref)
npy.testing.assert_allclose(rf.renormalize_s(ntw.s, 50, 50, s_def='power'), s_ref)
npy.testing.assert_allclose(rf.renormalize_s(ntw.s, 50, 50, s_def='pseudo'), s_ref)
npy.testing.assert_allclose(rf.renormalize_s(ntw.s, 50, 50, s_def='traveling'), s_ref)
# also check Z and Y matrices, just in case
z_ref = npy.array([[
[18.0000 -16.0000j, 20.0000 + 40.0000j],
[20.0000 +40.0000j, 10.0000 -80.0000j]]])
npy.testing.assert_allclose(ntw.z, z_ref, atol=1e-4)
y_ref = npy.array([[
[0.0251 +0.0023j, 0.0123 -0.0066j],
[0.0123 -0.0066j, 0.0052 +0.0055j]]])
npy.testing.assert_allclose(ntw.y, y_ref, atol=1e-4)
# creating network by specifying s-params definition
ntw_power = rf.Network(frequency=f0, s=s_ref, z0=50, s_def='power')
ntw_pseudo = rf.Network(frequency=f0, s=s_ref, z0=50, s_def='pseudo')
ntw_legacy = rf.Network(frequency=f0, s=s_ref, z0=50, s_def='traveling')
self.assertTrue(ntw_power == ntw_pseudo)
self.assertTrue(ntw_power == ntw_legacy)
def test_network_from_z_or_y(self):
' Construct a network from its z or y parameters '
# test for both real and complex char. impedance
# and for 2 frequencies
z0 = [npy.random.rand(), npy.random.rand()+1j*npy.random.rand()]
freqs = npy.array([1, 2])
# generate arbitrary complex z and y
z_ref = npy.random.rand(2,3,3) + 1j*npy.random.rand(2,3,3)
y_ref = npy.random.rand(2,3,3) + 1j*npy.random.rand(2,3,3)
# create networks from z or y and compare ntw.z to the reference
# check that the conversions work for all s-param definitions
for s_def in S_DEFINITIONS:
ntwk = rf.Network(s_def=s_def)
ntwk.z0 = rf.fix_z0_shape(z0, 2, 3)
ntwk.f = freqs
# test #1: define the network directly from z
ntwk.z = z_ref
npy.testing.assert_allclose(ntwk.z, z_ref)
# test #2: define the network from s, after z -> s (s_def is important)
ntwk.s = rf.z2s(z_ref, z0, s_def=s_def)
npy.testing.assert_allclose(ntwk.z, z_ref)
# test #3: define the network directly from y
ntwk.y = y_ref
npy.testing.assert_allclose(ntwk.y, y_ref)
# test #4: define the network from s, after y -> s (s_def is important)
ntwk.s = rf.y2s(y_ref, z0, s_def=s_def)
npy.testing.assert_allclose(ntwk.y, y_ref)
def test_z0_pure_imaginary(self):
' Test cases where z0 is pure imaginary '
# test that conversion to Z or Y does not give NaN for pure imag z0
for s_def in S_DEFINITIONS:
ntwk = rf.Network(s_def=s_def)
ntwk.z0 = npy.array([50j, -50j])
ntwk.f = npy.array([1000])
ntwk.s = npy.random.rand(1,2,2) + npy.random.rand(1,2,2)*1j
self.assertFalse(npy.any(npy.isnan(ntwk.z)))
self.assertFalse(npy.any(npy.isnan(ntwk.y)))
def test_z0_scalar(self):
'Test a scalar z0'
ntwk = rf.Network()
ntwk.z0 = 1
# Test setting the z0 before and after setting the s shape
self.assertEqual(ntwk.z0, 1)
ntwk.s = npy.random.rand(1,2,2)
ntwk.z0 = 10
self.assertTrue(npy.allclose(ntwk.z0, npy.full((1,2), 10)))
def test_z0_vector(self):
'Test a 1 dimensional z0'
ntwk = rf.Network()
z0 = [1,2]
# Test setting the z0 before and after setting the s shape
ntwk.z0 = [1,2] # Passing as List
self.assertTrue(npy.allclose(ntwk.z0, npy.array(z0, dtype=complex)))
ntwk.z0 = npy.array(z0[::-1]) # Passing as npy.array
self.assertTrue(npy.allclose(ntwk.z0, npy.array(z0[::-1], dtype=complex)))
# If the s-array has been set, the z0 value should broadcast to the required shape
ntwk.s = npy.random.rand(3,2,2)
ntwk.z0 = z0
self.assertTrue(npy.allclose(ntwk.z0, npy.array([z0, z0, z0], dtype=complex)))
# If the s-array has been set and we want to set z0 along the frequency axis,
# wer require the frequency vector to be set too.
# Unfortunately the frequency vector and the s shape can distinguish
z0 = [1,2,3]
ntwk.s = npy.random.rand(3,2,2)
with self.assertRaises(AttributeError):
ntwk.z0 = z0
ntwk.f = [1,2,3]
ntwk.z0 = z0[::-1]
self.assertTrue(npy.allclose(ntwk.z0, npy.array([z0[::-1], z0[::-1]], dtype=complex).T))
def test_z0_matrix(self):
ntwk = rf.Network()
z0 = [[1,2]]
ntwk.z0 = z0
self.assertTrue(npy.allclose(ntwk.z0, npy.array(z0, dtype=complex)))
ntwk.z0 = npy.array(z0) + 1 # Passing as npy.array
self.assertTrue(npy.allclose(ntwk.z0, npy.array(z0, dtype=complex)+1))
# Setting the frequency is required to be set, as the matrix size is checked against the
# frequency vector
ntwk.s = npy.random.rand(1,2,2)
ntwk.f = [1]
ntwk.z0 = z0
self.assertTrue(npy.allclose(ntwk.z0, npy.array(z0, dtype=complex)))
def test_yz(self):
tinyfloat = 1e-12
ntwk = rf.Network()
ntwk.z0 = npy.array([28,75+3j])
ntwk.f = npy.array([1000, 2000])
ntwk.s = rf.z2s(npy.array([[[1+1j,5,11],[40,5,3],[16,8,9+8j]],
[[1,20,3],[14,10,16],[27,18,-19-2j]]]))
self.assertTrue((abs(rf.y2z(ntwk.y)-ntwk.z) < tinyfloat).all())
self.assertTrue((abs(rf.y2s(ntwk.y, ntwk.z0)-ntwk.s) < tinyfloat).all())
self.assertTrue((abs(rf.z2y(ntwk.z)-ntwk.y) < tinyfloat).all())
self.assertTrue((abs(rf.z2s(ntwk.z, ntwk.z0)-ntwk.s) < tinyfloat).all())
def test_mul(self):
a = rf.N(f=[1,2],s=[1+2j, 3+4j],z0=1)
# operating on networks
self.assertTrue( ((a*a).s == npy.array([[[-3+4j]],[[-7+24j]]])).all())
# operating on numbers
self.assertTrue( ((2*a*2).s == npy.array([[[4+8j]],[[12+16j]]])).all())
# operating on list
self.assertTrue( ((a*[1,2]).s == npy.array([[[1+2j]],[[6+8j]]])).all())
self.assertTrue( (([1,2]*a).s == npy.array([[[1+2j]],[[6+8j]]])).all())
def test_sub(self):
a = rf.N(f=[1,2],s=[1+2j, 3+4j],z0=1)
# operating on networks
self.assertTrue( ((a-a).s == npy.array([[[0+0j]],[[0+0j]]])).all())
# operating on numbers
self.assertTrue( ((a-(2+2j)).s == npy.array([[[-1+0j]],[[1+2j]]])).all())
# operating on list
self.assertTrue( ((a-[1+1j,2+2j]).s == npy.array([[[0+1j]],[[1+2j]]])).all())
def test_div(self):
a = rf.N(f=[1,2],s=[1+2j, 3+4j],z0=1)
# operating on networks
self.assertTrue( ((a/a).s == npy.array([[[1+0j]],[[1+0j]]])).all())
# operating on numbers
self.assertTrue( ((a/2.).s == npy.array([[[.5+1j]],[[3/2.+2j]]])).all())
# operating on list
self.assertTrue( ((a/[1,2]).s == npy.array([[[1+2j]],[[3/2.+2j]]])).all())
def test_add(self):
a = rf.N(f=[1,2],s=[1+2j, 3+4j],z0=1)
# operating on networks
self.assertTrue( ((a+a).s == npy.array([[[2+4j]],[[6+8j]]])).all())
# operating on numbers
self.assertTrue( ((a+2+2j).s == npy.array([[[3+4j]],[[5+6j]]])).all())
# operating on list
self.assertTrue( ((a+[1+1j,2+2j]).s == npy.array([[[2+3j]],[[5+6j]]])).all())
def test_interpolate(self):
a = rf.N(f=[1,2],s=[1+2j, 3+4j],z0=1)
freq = rf.F.from_f(npy.linspace(1,2,4), unit='ghz')
b = a.interpolate(freq)
# TODO: numerically test for correct interpolation
def test_interpolate_rational(self):
a = rf.N(f=npy.linspace(1,2,5),s=npy.linspace(0,1,5)*(1+1j),z0=1)
freq = rf.F.from_f(npy.linspace(1,2,6,endpoint=True))
b = a.interpolate(freq, kind='rational')
self.assertFalse(any(npy.isnan(b.s)))
# Test that the endpoints are the equal
self.assertTrue(b.s[0] == a.s[0])
self.assertTrue(b.s[-1] == a.s[-1])
# Check that abs(S) is increasing
self.assertTrue(all(npy.diff(npy.abs(b.s.flatten())) > 0))
self.assertTrue(b.z0[0] == a.z0[0])
def test_interpolate_linear(self):
a = rf.N(f=[1,2],s=[1+2j, 3+4j],z0=[1,2])
freq = rf.F.from_f(npy.linspace(1,2,3,endpoint=True))
b = a.interpolate(freq, kind='linear')
self.assertFalse(any(npy.isnan(b.s)))
# Test that the endpoints are the equal
# Middle point can also be calculated in this case
self.assertTrue(b.s[0] == a.s[0])
self.assertTrue(b.s[1] == 0.5*(a.s[0] + a.s[1]))
self.assertTrue(b.s[-1] == a.s[-1])
# Check Z0 interpolation
self.assertTrue(b.z0[0] == a.z0[0])
self.assertTrue(b.z0[1] == 0.5*(a.z0[0] + a.z0[1]))
self.assertTrue(b.z0[-1] == a.z0[-1])
def test_interpolate_self_npoints(self):
a = rf.N(f=[1,2],s=[1+2j, 3+4j],z0=1)
a.interpolate_self_npoints(4)
# TODO: numerically test for correct interpolation
def test_interpolate_from_f(self):
a = rf.N(f=[1,2],s=[1+2j, 3+4j],z0=1)
a.interpolate_from_f(npy.linspace(1,2,4), unit='ghz')
# TODO: numerically test for correct interpolation
def test_slicer(self):
a = rf.Network(f=[1,2,4,5,6],
s=[1,1,1,1,1],
z0=50 )
b = a['2-5ghz']
tinyfloat = 1e-12
self.assertTrue((abs(b.frequency.f - [2e9,4e9,5e9]) < tinyfloat).all())
# Network classifiers
def test_is_reciprocal(self):
a = rf.Network(f=[1],
s=[[0, 1, 0],
[0, 0, 1],
[1, 0, 0]],
z0=50)
self.assertFalse(a.is_reciprocal(), 'A circulator is not reciprocal.')
b = rf.Network(f=[1],
s=[[0, 0.5, 0.5],
[0.5, 0, 0.5],
[0.5, 0.5, 0]],
z0=50)
self.assertTrue(b.is_reciprocal(), 'This power divider is reciprocal.')
return
def test_is_symmetric(self):
# 2-port
a = rf.Network(f=[1, 2, 3],
s=[[[-1, 0], [0, -1]],
[[-2, 0], [0, -2]],
[[1, 0], [0, 1]]],
z0=50)
self.assertTrue(a.is_symmetric(), 'A short is symmetric.')
self.assertRaises(ValueError, a.is_symmetric, port_order={1: 2}) # error raised by renumber()
a.s[0, 0, 0] = 1
self.assertFalse(a.is_symmetric(), 'non-symmetrical')
# another 2-port (transmission line with 201 frequency samples)
nw_line = rf.data.line
self.assertTrue(nw_line.is_symmetric())
# another 2-port (ring slot with 201 frequency samples)
nw_ringslot = rf.data.ring_slot
self.assertFalse(nw_ringslot.is_symmetric())
# 3-port
b = rf.Network(f=[1, 3],
s=[[[0, 0.5, 0.5], [0.5, 0, 0.5], [0.5, 0.5, 0]],
[[0, 0.2, 0.2], [0.2, 0, 0.2], [0.2, 0.2, 0]]],
z0=50)
with self.assertRaises(ValueError) as context:
b.is_symmetric()
self.assertEqual(str(context.exception),
'Using is_symmetric() is only valid for a 2N-port network (N=2,4,6,8,...)')
# 4-port
c = rf.Network(f=[1, 3, 5, 6],
s=[[[0, 1j, 1, 0], [1j, 0, 0, 1], [1, 0, 0, 1j], [0, 1, 1j, 0]],
[[0, 0.8j, 0.7, 0], [0.8j, 0, 0, 0.7], [0.7, 0, 0, 0.8j], [0, 0.7, 0.8j, 0]],
[[0, 0.3j, 1, 0], [0.3j, 0, 0, 1], [1, 0, 0, 0.3j], [0, 1, 0.3j, 0]],
[[0, -1j, -1, 0], [-1j, 0, 0, -1], [-1, 0, 0, -1j], [0, -1, -1j, 0]]],
z0=50)
self.assertTrue(c.is_symmetric(n=2), 'This quadrature hybrid coupler is symmetric.')
self.assertTrue(c.is_symmetric(n=2, port_order={0: 1, 1: 2, 2: 3, 3: 0}),
'This quadrature hybrid coupler is symmetric even after rotation.')
with self.assertRaises(ValueError) as context:
c.is_symmetric(n=3)
self.assertEqual(str(context.exception), 'specified order n = 3 must be between 1 and N = 2, inclusive')
d = rf.Network(f=[1],
s=[[1, 0, 0, 0],
[1, 0, 0, 0],
[1, 0, 0, 1],
[0, 1, 0, 1]],
z0=50)
self.assertTrue(d.is_symmetric(n=1), 'This contrived non-reciprocal device has a line of symmetry.')
self.assertFalse(d.is_symmetric(n=2), 'This device only has first-order line symmetry.')
self.assertFalse(d.is_symmetric(port_order={0: 1, 1: 0}),
'This device is no longer symmetric after reordering ports 1 and 2.')
self.assertTrue(d.is_symmetric(port_order={0: 1, 1: 0, 2: 3, 3: 2}),
'This device is symmetric after swapping ports 1 with 2 and 3 with 4.')
# 6-port
x = rf.Network(f=[1],
s=[[0, 0, 0, 0, 0, 0],
[0, 1, 9, 0, 0, 0],
[0, 0, 2, 0, 0, 0],
[0, 0, 0, 2, 0, 0],
[0, 0, 0, 9, 1, 0],
[0, 0, 0, 0, 0, 0]],
z0=50)
self.assertFalse(x.is_symmetric(n=3))
self.assertFalse(x.is_symmetric(n=2))
self.assertTrue(x.is_symmetric(n=1))
self.assertTrue(x.is_symmetric(n=1, port_order={-3: -1, -1: -3, 0: 2, 2: 0}))
# 8-port
s8p_diag = [1j, -1j, -1j, 1j, 1j, -1j, -1j, 1j]
s8p_mat = npy.identity(8, dtype=complex)
for row in range(8):
s8p_mat[row, :] *= s8p_diag[row]
y = rf.Network(f=[1],
s=s8p_mat,
z0=50)
self.assertTrue(y.is_symmetric())
self.assertTrue(y.is_symmetric(n=2))
self.assertFalse(y.is_symmetric(n=4))
return
def test_is_passive(self):
a = rf.Network(f=[1],
s=[[0, 0.5, 0.5],
[0.5, 0, 0.5],
[0.5, 0.5, 0]],
z0=50)
self.assertTrue(a.is_passive(), 'This power divider is passive.')
b = rf.Network(f=[1],
s=[[0, 0],
[10, 0]],
z0=50)
self.assertFalse(b.is_passive(), 'A unilateral amplifier is not passive.')
return
def test_is_lossless(self):
a = rf.Network(f=[1],
s=[[0, 0.5, 0.5],
[0.5, 0, 0.5],
[0.5, 0.5, 0]],
z0=50)
self.assertFalse(a.is_lossless(), 'A resistive power divider is lossy.')
b = rf.Network(f=[1],
s=[[0, -1j/npy.sqrt(2), -1j/npy.sqrt(2)],
[-1j/npy.sqrt(2), 1./2, -1./2],
[-1j/npy.sqrt(2), -1./2, 1./2]],
z0=50)
self.assertTrue(b.is_lossless(), 'This unmatched power divider is lossless.')
return
def test_noise(self):
a = rf.Network(os.path.join(self.test_dir,'ntwk_noise.s2p'))
nf = 10**(0.05)
self.assertTrue(a.noisy)
self.assertTrue(abs(a.nfmin[0] - nf) < 1.e-6, 'noise figure does not match original spec')
self.assertTrue(abs(a.z_opt[0] - 50.) < 1.e-6, 'optimal resistance does not match original spec')
self.assertTrue(abs(a.rn[0] - 0.1159*50.) < 1.e-6, 'equivalent resistance does not match original spec')
self.assertTrue(npy.all(abs(a.g_opt) < 1.e-6), 'calculated optimal reflection coefficient does not match original coefficients')
b = rf.Network(f=[1, 2],
s=[[[0, 1], [1, 0]], [[0, 1], [1, 0]]],
z0=50).interpolate(a.frequency)
with self.assertRaises(ValueError) as context:
b.n
with self.assertRaises(ValueError) as context:
b.f_noise
self.assertEqual(str(context.exception), 'network does not have noise')
c = a ** b
self.assertTrue(a.noisy)
self.assertTrue(abs(c.nfmin[0] - nf) < 1.e-6, 'noise figure does not match original spec')
self.assertTrue(abs(c.z_opt[0] - 50.) < 1.e-6, 'optimal resistance does not match original spec')
self.assertTrue(abs(c.rn[0] - 0.1159*50.) < 1.e-6, 'equivalent resistance does not match original spec')
d = b ** a
self.assertTrue(d.noisy)
self.assertTrue(abs(d.nfmin[0] - nf) < 1.e-6, 'noise figure does not match original spec')
self.assertTrue(abs(d.z_opt[0] - 50.) < 1.e-6, 'optimal resistance does not match original spec')
self.assertTrue(abs(d.rn[0] - 0.1159*50.) < 1.e-6, 'equivalent resistance does not match original spec')
e = a ** a
self.assertTrue(abs(e.nfmin[0] - (nf + (nf-1)/(10**2))) < 1.e-6, 'noise figure does not match Friis formula')
self.assertTrue(a.noisy)
self.assertTrue(abs(a.nfmin[0] - nf) < 1.e-6, 'noise figure was altered')
self.assertTrue(abs(a.z_opt[0] - 50.) < 1.e-6, 'optimal resistance was altered')
self.assertTrue(abs(a.rn[0] - 0.1159*50.) < 1.e-6, 'equivalent resistance was altered')
tem = DistributedCircuit(z0=50)
inductor = tem.inductor(1e-9).interpolate(a.frequency)
f = inductor ** a
expected_zopt = 50 - 2j*npy.pi*1e+9*1e-9
self.assertTrue(abs(f.z_opt[0] - expected_zopt) < 1.e-6, 'optimal resistance was not 50 ohms - inductor')
return
def test_noise_dc_extrapolation(self):
ntwk = rf.Network(os.path.join(self.test_dir,'ntwk_noise.s2p'))
ntwk = ntwk["0-1.5GHz"] # using only the first samples, as ntwk_noise has duplicate x value
s11 = ntwk.s11
s11_dc = s11.extrapolate_to_dc(kind='cubic')
def test_dc_extrapolation_dc_sparam(self):
zeros = npy.zeros((self.ntwk1.nports, self.ntwk1.nports))
net_dc = self.ntwk1.extrapolate_to_dc(dc_sparam=zeros)
net_dc = self.ntwk1.extrapolate_to_dc(dc_sparam=zeros.tolist())
def test_noise_deembed(self):
f1_ =[75.5, 75.5] ; f2_=[75.5, 75.6] ; npt_ = [1,2] # single freq and multifreq
for f1,f2,npt in zip (f1_,f2_,npt_) :
freq=rf.Frequency(f1,f2,npt,'ghz')
ntwk4_n = rf.Network(os.path.join(self.test_dir,'ntwk4_n.s2p'), f_unit='GHz').interpolate(freq)
ntwk4 = rf.Network(os.path.join(self.test_dir,'ntwk4.s2p'),f_unit='GHz').interpolate(freq)
thru = rf.Network(os.path.join(self.test_dir,'thru.s2p'),f_unit='GHz').interpolate(freq)
ntwk4_thru = ntwk4 ** thru ;ntwk4_thru.name ='ntwk4_thru'
retrieve_thru = ntwk4.inv ** ntwk4_thru ;retrieve_thru.name ='retrieve_thru'
self.assertEqual(retrieve_thru, thru)
self.assertTrue(ntwk4_thru.noisy)
self.assertTrue(retrieve_thru.noisy)
self.assertTrue((abs(thru.nfmin - retrieve_thru.nfmin) < 1.e-6).all(), 'nf not retrieved by noise deembed')
self.assertTrue((abs(thru.rn - retrieve_thru.rn) < 1.e-6).all(), 'rn not retrieved by noise deembed')
self.assertTrue((abs(thru.z_opt - retrieve_thru.z_opt) < 1.e-6).all(), 'noise figure does not match original spec')
ntwk4_n_thru = ntwk4_n ** thru ;ntwk4_n_thru.name ='ntwk4_n_thru'
retrieve_n_thru = ntwk4_n.inv ** ntwk4_n_thru ;retrieve_n_thru.name ='retrieve_n_thru'
self.assertTrue(ntwk4_n_thru.noisy)
self.assertEqual(retrieve_n_thru, thru)
self.assertTrue(ntwk4_n_thru.noisy)
self.assertTrue(retrieve_n_thru.noisy)
self.assertTrue((abs(thru.nfmin - retrieve_n_thru.nfmin) < 1.e-6).all(), 'nf not retrieved by noise deembed')
self.assertTrue((abs(thru.rn - retrieve_n_thru.rn) < 1.e-6).all(), 'rn not retrieved by noise deembed')
self.assertTrue((abs(thru.z_opt - retrieve_n_thru.z_opt) < 1.e-6).all(), 'noise figure does not match original spec')
tuner, x,y,g = tuner_constellation()
newnetw = thru.copy()
nfmin_set=4.5; gamma_opt_set=complex(.7,-0.2); rn_set=1
newnetw.set_noise_a(thru.noise_freq, nfmin_db=nfmin_set, gamma_opt=gamma_opt_set, rn=rn_set )
z = newnetw.nfdb_gs(g)[:,0]
freq = thru.noise_freq.f[0]
gamma_opt_rb, nfmin_rb = plot_contour(freq,x,y,z, min0max1=0, graph=False)
self.assertTrue(abs(nfmin_set - nfmin_rb) < 1.e-2, 'nf not retrieved by noise deembed')
self.assertTrue(abs(gamma_opt_rb.s[0,0,0] - gamma_opt_set) < 1.e-1, 'nf not retrieved by noise deembed')
def test_se2gmm2se_mag(self):
for z0 in [None, 45, 75]:
ntwk4 = rf.Network(os.path.join(self.test_dir, 'cst_example_4ports.s4p'))
if z0 is not None:
ntwk4.z0 = z0
ntwk4t = deepcopy(ntwk4)
ntwk4t.se2gmm(p=2)
ntwk4t.gmm2se(p=2)
self.assertTrue(npy.allclose(abs(ntwk4.s), abs(ntwk4t.s), rtol=1E-7, atol=0))
self.assertTrue(npy.allclose(ntwk4.z0, ntwk4t.z0))
# phase testing does not pass - see #367
#self.assertTrue(npy.allclose(npy.angle(ntwk4.s), npy.angle(ntwk4t.s), rtol=1E-7, atol=1E-10))
def test_s_active(self):
"""
Test the active s-parameters of a 2-ports network
"""
s_ref = self.ntwk1.s
# s_act should be equal to s11 if a = [1,0]
npy.testing.assert_array_almost_equal(rf.s2s_active(s_ref, [1, 0])[:,0], s_ref[:,0,0])
# s_act should be equal to s22 if a = [0,1]
npy.testing.assert_array_almost_equal(rf.s2s_active(s_ref, [0, 1])[:,1], s_ref[:,1,1])
# s_act should be equal to s11 if a = [1,0]
npy.testing.assert_array_almost_equal(self.ntwk1.s_active([1, 0])[:,0], s_ref[:,0,0])
# s_act should be equal to s22 if a = [0,1]
npy.testing.assert_array_almost_equal(self.ntwk1.s_active([0, 1])[:,1], s_ref[:,1,1])
def test_vswr_active(self):
"""
Test the active vswr-parameters of a 2-ports network
"""
s_ref = self.ntwk1.s
vswr_ref = self.ntwk1.s_vswr
# vswr_act should be equal to vswr11 if a = [1,0]
npy.testing.assert_array_almost_equal(rf.s2vswr_active(s_ref, [1, 0])[:,0], vswr_ref[:,0,0])
# vswr_act should be equal to vswr22 if a = [0,1]
npy.testing.assert_array_almost_equal(rf.s2vswr_active(s_ref, [0, 1])[:,1], vswr_ref[:,1,1])
# vswr_act should be equal to vswr11 if a = [1,0]
npy.testing.assert_array_almost_equal(self.ntwk1.vswr_active([1, 0])[:,0], vswr_ref[:,0,0])
# vswr_act should be equal to vswr22 if a = [0,1]
npy.testing.assert_array_almost_equal(self.ntwk1.vswr_active([0, 1])[:,1], vswr_ref[:,1,1])
def test_generate_subnetworks_nportsbelow10(self):
"""
Testing generation of one-port subnetworks for ports below 10
"""
ntwk = rf.Network(os.path.join(self.test_dir,'ntwk.s32p'))
npy.testing.assert_array_almost_equal(
ntwk.s[:,4,5],
ntwk.s5_6.s[:,0,0]
)
def test_generate_subnetworks_nportsabove10(self):
"""
Testing generation of one-port subnetworks for ports above 10
"""
ntwk = rf.Network(os.path.join(self.test_dir,'ntwk.s32p'))
npy.testing.assert_array_almost_equal(
ntwk.s[:,1,15],
ntwk.s2_16.s[:,0,0]
)
def test_generate_subnetwork_nounderscore(self):
"""
Testing no underscore alias of one-port subnetworks for ports below 10.
This is for backward compatibility with old code.
"""
ntwk = rf.Network(os.path.join(self.test_dir,'ntwk.s32p'))
npy.testing.assert_array_almost_equal(
ntwk.s[:, 8, 8],
ntwk.s99.s[:,0,0]
)
def test_generate_subnetworks_allports(self):
"""
Testing generation of all one-port subnetworks in case of edge problems.
"""
ntwk = rf.Network(os.path.join(self.test_dir,'ntwk.s32p'))
for m in range(ntwk.nports):
for n in range(ntwk.nports):
npy.testing.assert_array_almost_equal(
ntwk.s[:,m,n],
ntwk.__getattribute__(f's{m+1}_{n+1}').s[:,0,0]
)
def test_subnetwork(self):
""" Test subnetwork creation and recombination """
tee = rf.data.tee # 3 port Network
# modify the z0 to dummy values just to check it works for any z0
tee.z0 = npy.random.rand(3) + 1j*npy.random.rand(3)
# Using rf.subnetwork()
# 2 port Networks as if one measures the tee with a 2 ports VNA
tee12 = rf.subnetwork(tee, [0, 1]) # 2 port Network from ports 1 & 2, port 3 matched
tee23 = rf.subnetwork(tee, [1, 2]) # 2 port Network from ports 2 & 3, port 1 matched
tee13 = rf.subnetwork(tee, [0, 2]) # 2 port Network from ports 1 & 3, port 2 matched
# recreate the original 3 ports Network from the thee 2-port sub-Networks
ntw_list = [tee12, tee23, tee13]
tee2 = rf.n_twoports_2_nport(ntw_list, nports=3)
self.assertTrue(tee2 == tee)
# Same from the subnetwork() method.
tee12 = tee.subnetwork([0, 1])
tee23 = tee.subnetwork([1, 2])
tee13 = tee.subnetwork([0, 2])
ntw_list = [tee12, tee23, tee13]
tee2 = rf.n_twoports_2_nport(ntw_list, nports=3)
self.assertTrue(tee2 == tee)
def test_invalid_freq(self):
dat = npy.arange(5)
dat[4] = 3
with self.assertWarns(InvalidFrequencyWarning):
freq = rf.Frequency.from_f(dat, unit='Hz')
s = npy.tile(dat,4).reshape(2,2,-1).T
with self.assertWarns(InvalidFrequencyWarning):
net = rf.Network(s=s, frequency=freq, z0=dat)
net.drop_non_monotonic_increasing()
self.assertTrue(npy.allclose(net.f, freq.f[:4]))
self.assertTrue(npy.allclose(net.s, s[:4]))
self.assertFalse(npy.allclose(net.s.shape, s.shape))
class NetworkTestCase(unittest.TestCase):
'''
Network class operation test case.
The following is true, as tested by lihan in ADS,
test3 == test1 ** test2
To test for 2N-port deembeding Meas, Fix and DUT are created such as:
::
Meas == Fix ** DUT
Meas Fix DUT
+---------+ +---------+ +---------+
-|0 4|- -|0 4|---|0 4|-
-|1 5|- = -|1 5|---|1 5|-
-|2 6|- -|2 6|---|2 6|-
-|3 7|- -|3 7|---|3 7|-
+---------+ +---------+ +---------+
Note:
-----
due to the complexity of inv computations, there will be an unavoidable
precision loss. thus Fix.inv ** Meas will show a small difference with DUT.
'''
def setUp(self):
'''
this also tests the ability to read touchstone files
without an error
'''
setup_pylab()
self.test_dir = os.path.dirname(os.path.abspath(__file__)) + '/'
self.ntwk1 = rf.Network(os.path.join(self.test_dir, 'ntwk1.s2p'))
self.ntwk2 = rf.Network(os.path.join(self.test_dir, 'ntwk2.s2p'))
self.ntwk3 = rf.Network(os.path.join(self.test_dir, 'ntwk3.s2p'))
self.freq = rf.Frequency(75, 110, 101, 'ghz')
self.cpw = CPW(self.freq, w=10e-6, s=5e-6, ep_r=10.6)
l1 = self.cpw.line(0.20, 'm', z0=50)
l2 = self.cpw.line(0.07, 'm', z0=50)
l3 = self.cpw.line(0.47, 'm', z0=50)
self.Fix = rf.concat_ports([l1, l1, l1, l1])
self.DUT = rf.concat_ports([l2, l2, l2, l2])
self.Meas = rf.concat_ports([l3, l3, l3, l3])
def test_timedomain(self):
t = self.ntwk1.s11.s_time
s = self.ntwk1.s11.s
self.assertTrue(len(t) == len(s))
def test_time_gate(self):
ntwk = self.ntwk1
gated = self.ntwk1.s11.time_gate(0, .2)
self.assertTrue(len(gated) == len(ntwk))
def test_time_transform(self):
spb = (4, 5)
data_rate = 5e9
num_taps = (100, 101)
for i in range(2):
tps = 1. / spb[i] / data_rate
num_points = spb[i] * num_taps[i]
# Frequency terms should NOT contain Nyquist frequency if number of points is odd
inc_nyq = True if num_points % 2 == 0 else False
freq = npy.linspace(0,
1. / 2 / tps,
num_points // 2 + 1,
endpoint=inc_nyq)
dut = self.ntwk1.copy()
freq_valid = freq[npy.logical_and(freq >= dut.f[0],
freq <= dut.f[-1])]
dut.interpolate_self(rf.Frequency.from_f(freq_valid, unit='hz'))
dut_dc = dut.extrapolate_to_dc()
t, y = dut_dc.s21.impulse_response(n=num_points)
self.assertEqual(len(t), num_points)
self.assertEqual(len(y), num_points)
self.assertTrue(npy.isclose(t[1] - t[0], tps))
t, y = dut_dc.s21.step_response(n=num_points)
self.assertEqual(len(t), num_points)
self.assertEqual(len(y), num_points)
self.assertTrue(npy.isclose(t[1] - t[0], tps))
def test_constructor_empty(self):
rf.Network()
def test_constructor_from_values(self):
rf.Network(f=[1, 2], s=[1, 2], z0=[1, 2])
def test_constructor_from_touchstone(self):
rf.Network(os.path.join(self.test_dir, 'ntwk1.s2p'))
def test_constructor_from_hfss_touchstone(self):
# HFSS can provide the port characteric impedances in its generated touchstone file.
# Check if reading a HFSS touchstone file with non-50Ohm impedances
ntwk_hfss = rf.Network(
os.path.join(self.test_dir, 'hfss_threeport_DB.s3p'))
self.assertFalse(npy.isclose(ntwk_hfss.z0[0, 0], 50))
def test_constructor_from_pickle(self):
rf.Network(os.path.join(self.test_dir, 'ntwk1.ntwk'))
def test_constructor_from_fid_touchstone(self):
filename = os.path.join(self.test_dir, 'ntwk1.s2p')
with open(filename, 'rb') as fid:
rf.Network(fid)
def test_open_saved_touchstone(self):
self.ntwk1.write_touchstone('ntwk1Saved', dir=self.test_dir)
ntwk1Saved = rf.Network(os.path.join(self.test_dir, 'ntwk1Saved.s2p'))
self.assertEqual(self.ntwk1, ntwk1Saved)
os.remove(os.path.join(self.test_dir, 'ntwk1Saved.s2p'))
def test_pickling(self):
original_ntwk = self.ntwk1
with tempfile.NamedTemporaryFile(dir=self.test_dir,
suffix='ntwk') as fid:
pickle.dump(original_ntwk, fid,
protocol=2) # Default Python2: 0, Python3: 3
fid.seek(0)
unpickled = pickle.load(fid)
self.assertEqual(original_ntwk, unpickled)
def test_stitch(self):
tmp = self.ntwk1.copy()
tmp.f = tmp.f + tmp.f[0]
c = rf.stitch(self.ntwk1, tmp)
def test_cascade(self):
self.assertEqual(self.ntwk1**self.ntwk2, self.ntwk3)
self.assertEqual(self.Fix**self.DUT**self.Fix.flipped(), self.Meas)
def test_connect(self):
self.assertEqual(rf.connect(self.ntwk1, 1, self.ntwk2, 0) , \
self.ntwk3)
xformer = rf.Network()
xformer.frequency = (1, )
xformer.s = ((0, 1), (1, 0)) # connects thru
xformer.z0 = (50, 25) # transforms 50 ohm to 25 ohm
c = rf.connect(xformer, 0, xformer,
1) # connect 50 ohm port to 25 ohm port
self.assertTrue(
npy.all(npy.abs(c.s - rf.impedance_mismatch(50, 25)) < 1e-6))
def test_connect_multiports(self):
a = rf.Network()
a.frequency = (1, )
a.s = npy.arange(16).reshape(4, 4)
a.z0 = npy.arange(4) + 1 # Z0 should never be zero
b = rf.Network()
b.frequency = (1, )
b.s = npy.arange(16).reshape(4, 4)
b.z0 = npy.arange(4) + 10
c = rf.connect(a, 2, b, 0, 2)
self.assertTrue((c.z0 == [1, 2, 12, 13]).all())
d = rf.connect(a, 0, b, 0, 3)
self.assertTrue((d.z0 == [4, 13]).all())
def test_connect_fast(self):
raise SkipTest('not supporting this function currently ')
self.assertEqual(rf.connect_fast(self.ntwk1, 1, self.ntwk2, 0) , \
self.ntwk3)
xformer = rf.Network()
xformer.frequency = (1, )
xformer.s = ((0, 1), (1, 0)) # connects thru
xformer.z0 = (50, 25) # transforms 50 ohm to 25 ohm
c = rf.connect_fast(xformer, 0, xformer,
1) # connect 50 ohm port to 25 ohm port
self.assertTrue(
npy.all(npy.abs(c.s - rf.impedance_mismatch(50, 25)) < 1e-6))
def test_flip(self):
self.assertEqual(rf.connect(self.ntwk1, 1, self.ntwk2, 0) , \
self.ntwk3)
gain = rf.Network()
gain.frequency = (1, )
gain.s = ((0, 2), (0.5, 0)) # connects thru with gain of 2.0
gain.z0 = (37, 82)
flipped = gain.copy()
flipped.flip()
c = rf.connect(gain, 1, flipped, 0)
self.assertTrue(
npy.all(npy.abs(c.s - npy.array([[0, 1], [1, 0]])) < 1e-6))
def test_de_embed_by_inv(self):
self.assertEqual(self.ntwk1.inv**self.ntwk3, self.ntwk2)
self.assertEqual(self.ntwk3**self.ntwk2.inv, self.ntwk1)
self.assertEqual(self.Fix.inv**self.Meas**self.Fix.flipped().inv,
self.DUT)
def test_plot_one_port_db(self):
self.ntwk1.plot_s_db(0, 0)
def test_plot_one_port_deg(self):
self.ntwk1.plot_s_deg(0, 0)
def test_plot_one_port_smith(self):
self.ntwk1.plot_s_smith(0, 0)
def test_plot_two_port_db(self):
self.ntwk1.plot_s_db()
def test_plot_two_port_deg(self):
self.ntwk1.plot_s_deg()
def test_plot_two_port_smith(self):
self.ntwk1.plot_s_smith()
def test_zy_singularities(self):
open = rf.N(f=[1], s=[1], z0=[50])
short = rf.N(f=[1], s=[-1], z0=[50])
react = rf.N(f=[1], s=[[0, 1], [1, 0]], z0=50)
z = open.z
y = short.y
a = react.y
def test_conversions(self):
#Converting to other format and back to S-parameters should return the original network
tinyfloat = 1e-11
for test_z0 in (50, 10, 90 + 10j, 4 - 100j):
for test_ntwk in (self.ntwk1, self.ntwk2, self.ntwk3):
ntwk = rf.Network(s=test_ntwk.s, f=test_ntwk.f, z0=test_z0)
self.assertTrue(
(abs(rf.a2s(rf.s2a(ntwk.s, test_z0), test_z0) - ntwk.s) <
tinyfloat).all())
self.assertTrue(
(abs(rf.z2s(rf.s2z(ntwk.s, test_z0), test_z0) - ntwk.s) <
tinyfloat).all())
self.assertTrue(
(abs(rf.y2s(rf.s2y(ntwk.s, test_z0), test_z0) - ntwk.s) <
tinyfloat).all())
self.assertTrue(
(abs(rf.h2s(rf.s2h(ntwk.s, test_z0), test_z0) - ntwk.s) <
tinyfloat).all())
self.assertTrue(
(abs(rf.t2s(rf.s2t(ntwk.s)) - ntwk.s) < tinyfloat).all())
self.assertTrue(
(abs(rf.t2s(rf.s2t(self.Fix.s)) - self.Fix.s) < tinyfloat).all())
def test_yz(self):
tinyfloat = 1e-12
ntwk = rf.Network()
ntwk.z0 = npy.array([28, 75 + 3j])
ntwk.f = npy.array([1000, 2000])
ntwk.s = rf.z2s(
npy.array([[[1 + 1j, 5, 11], [40, 5, 3], [16, 8, 9 + 8j]],
[[1, 20, 3], [14, 10, 16], [27, 18, -19 - 2j]]]))
self.assertTrue((abs(rf.y2z(ntwk.y) - ntwk.z) < tinyfloat).all())
self.assertTrue(
(abs(rf.y2s(ntwk.y, ntwk.z0) - ntwk.s) < tinyfloat).all())
self.assertTrue((abs(rf.z2y(ntwk.z) - ntwk.y) < tinyfloat).all())
self.assertTrue(
(abs(rf.z2s(ntwk.z, ntwk.z0) - ntwk.s) < tinyfloat).all())
def test_mul(self):
a = rf.N(f=[1, 2], s=[1 + 2j, 3 + 4j], z0=1)
# operating on networks
self.assertTrue(((a * a).s == npy.array([[[-3 + 4j]],
[[-7 + 24j]]])).all())
# operating on numbers
self.assertTrue(((2 * a * 2).s == npy.array([[[4 + 8j]],
[[12 + 16j]]])).all())
# operating on list
self.assertTrue(((a * [1, 2]).s == npy.array([[[1 + 2j]],
[[6 + 8j]]])).all())
self.assertTrue((([1, 2] * a).s == npy.array([[[1 + 2j]],
[[6 + 8j]]])).all())
def test_sub(self):
a = rf.N(f=[1, 2], s=[1 + 2j, 3 + 4j], z0=1)
# operating on networks
self.assertTrue(((a - a).s == npy.array([[[0 + 0j]],
[[0 + 0j]]])).all())
# operating on numbers
self.assertTrue(((a - (2 + 2j)).s == npy.array([[[-1 + 0j]],
[[1 + 2j]]])).all())
# operating on list
self.assertTrue(
((a - [1 + 1j, 2 + 2j]).s == npy.array([[[0 + 1j]],
[[1 + 2j]]])).all())
def test_div(self):
a = rf.N(f=[1, 2], s=[1 + 2j, 3 + 4j], z0=1)
# operating on networks
self.assertTrue(((a / a).s == npy.array([[[1 + 0j]],
[[1 + 0j]]])).all())
# operating on numbers
self.assertTrue(((a / 2.).s == npy.array([[[.5 + 1j]],
[[3 / 2. + 2j]]])).all())
# operating on list
self.assertTrue(((a / [1, 2]).s == npy.array([[[1 + 2j]],
[[3 / 2. + 2j]]])).all())
def test_add(self):
a = rf.N(f=[1, 2], s=[1 + 2j, 3 + 4j], z0=1)
# operating on networks
self.assertTrue(((a + a).s == npy.array([[[2 + 4j]],
[[6 + 8j]]])).all())
# operating on numbers
self.assertTrue(((a + 2 + 2j).s == npy.array([[[3 + 4j]],
[[5 + 6j]]])).all())
# operating on list
self.assertTrue(
((a + [1 + 1j, 2 + 2j]).s == npy.array([[[2 + 3j]],
[[5 + 6j]]])).all())
def test_interpolate(self):
a = rf.N(f=[1, 2], s=[1 + 2j, 3 + 4j], z0=1)
freq = rf.F.from_f(npy.linspace(1, 2, 4), unit='ghz')
b = a.interpolate(freq)
# TODO: numerically test for correct interpolation
def test_interpolate_rational(self):
a = rf.N(f=[1, 2], s=[1 + 2j, 3 + 4j], z0=1)
freq = rf.F.from_f(npy.linspace(1, 2, 4), unit='ghz')
b = a.interpolate(freq, kind='rational')
# TODO: numerically test for correct interpolation
def test_interpolate_self_npoints(self):
a = rf.N(f=[1, 2], s=[1 + 2j, 3 + 4j], z0=1)
a.interpolate_self_npoints(4)
# TODO: numerically test for correct interpolation
def test_interpolate_from_f(self):
a = rf.N(f=[1, 2], s=[1 + 2j, 3 + 4j], z0=1)
a.interpolate_from_f(npy.linspace(1, 2, 4), unit='ghz')
# TODO: numerically test for correct interpolation
def test_slicer(self):
a = rf.Network(f=[1, 2, 4, 5, 6], s=[1, 1, 1, 1, 1], z0=50)
b = a['2-5ghz']
tinyfloat = 1e-12
self.assertTrue(
(abs(b.frequency.f - [2e9, 4e9, 5e9]) < tinyfloat).all())
# Network classifiers
def test_is_reciprocal(self):
a = rf.Network(f=[1, 2], s=[[0, 1, 0], [0, 0, 1], [1, 0, 0]], z0=50)
self.assertFalse(a.is_reciprocal(), 'A circulator is not reciprocal.')
b = rf.Network(f=[1, 2],
s=[[0, 0.5, 0.5], [0.5, 0, 0.5], [0.5, 0.5, 0]],
z0=50)
self.assertTrue(b.is_reciprocal(), 'This power divider is reciprocal.')
return
def test_is_symmetric(self):
# 2-port
a = rf.Network(f=[1, 2], s=[[-1, 0], [0, -1]], z0=50)
self.assertTrue(a.is_symmetric(), 'A short is symmetric.')
self.assertRaises(ValueError, a.is_symmetric,
port_order={1: 2}) # error raised by renumber()
a.s[0, 0, 0] = 1
self.assertFalse(a.is_symmetric(), 'non-symmetrical')
# 3-port
b = rf.Network(f=[1, 2],
s=[[0, 0.5, 0.5], [0.5, 0, 0.5], [0.5, 0.5, 0]],
z0=50)
with self.assertRaises(ValueError) as context:
b.is_symmetric()
self.assertEqual(
str(context.exception),
'test of symmetric is only valid for a 2N-port network')
# 4-port
c = rf.Network(f=[1, 2],
s=[[0, 1j, 1, 0], [1j, 0, 0, 1], [1, 0, 0, 1j],
[0, 1, 1j, 0]],
z0=50)
self.assertTrue(c.is_symmetric(n=2),
'This quadrature hybrid coupler is symmetric.')
self.assertTrue(
c.is_symmetric(n=2, port_order={
0: 1,
1: 2,
2: 3,
3: 0
}),
'This quadrature hybrid coupler is symmetric even after rotation.')
with self.assertRaises(ValueError) as context:
c.is_symmetric(n=3)
self.assertEqual(
str(context.exception),
'specified order n = 3 must be between 1 and N = 2, inclusive')
d = rf.Network(f=[1, 2],
s=[[1, 0, 0, 0], [1, 0, 0, 0], [1, 0, 0, 1],
[0, 1, 0, 1]],
z0=50)
self.assertTrue(
d.is_symmetric(n=1),
'This contrived non-reciprocal device has a line of symmetry.')
self.assertFalse(d.is_symmetric(n=2),
'This device only has first-order line symmetry.')
self.assertFalse(
d.is_symmetric(port_order={
0: 1,
1: 0
}),
'This device is no longer symmetric after reordering ports 1 and 2.'
)
self.assertTrue(
d.is_symmetric(port_order={
0: 1,
1: 0,
2: 3,
3: 2
}),
'This device is symmetric after swapping ports 1 with 2 and 3 with 4.'
)
# 6-port
x = rf.Network(f=[1, 2],
s=[[0, 0, 0, 0, 0, 0], [0, 1, 9, 0, 0, 0],
[0, 0, 2, 0, 0, 0], [0, 0, 0, 2, 0, 0],
[0, 0, 0, 9, 1, 0], [0, 0, 0, 0, 0, 0]],
z0=50)
self.assertFalse(x.is_symmetric(n=3))
self.assertFalse(x.is_symmetric(n=2))
self.assertTrue(x.is_symmetric(n=1))
self.assertTrue(
x.is_symmetric(n=1, port_order={
-3: -1,
-1: -3,
0: 2,
2: 0
}))
# 8-port
s8p_diag = [1j, -1j, -1j, 1j, 1j, -1j, -1j, 1j]
s8p_mat = npy.identity(8, dtype=complex)
for row in range(8):
s8p_mat[row, :] *= s8p_diag[row]
y = rf.Network(f=[1, 2], s=s8p_mat, z0=50)
self.assertTrue(y.is_symmetric())
self.assertTrue(y.is_symmetric(n=2))
self.assertFalse(y.is_symmetric(n=4))
return
def test_is_passive(self):
a = rf.Network(f=[1, 2],
s=[[0, 0.5, 0.5], [0.5, 0, 0.5], [0.5, 0.5, 0]],
z0=50)
self.assertTrue(a.is_passive(), 'This power divider is passive.')
b = rf.Network(f=[1, 2], s=[[0, 0], [10, 0]], z0=50)
self.assertFalse(b.is_passive(),
'A unilateral amplifier is not passive.')
return
def test_is_lossless(self):
a = rf.Network(f=[1, 2],
s=[[0, 0.5, 0.5], [0.5, 0, 0.5], [0.5, 0.5, 0]],
z0=50)
self.assertFalse(a.is_lossless(),
'A resistive power divider is lossy.')
b = rf.Network(f=[1, 2],
s=[[0, -1j / npy.sqrt(2), -1j / npy.sqrt(2)],
[-1j / npy.sqrt(2), 1. / 2, -1. / 2],
[-1j / npy.sqrt(2), -1. / 2, 1. / 2]],
z0=50)
self.assertTrue(b.is_lossless(),
'This unmatched power divider is lossless.')
return
def test_noise(self):
a = rf.Network(os.path.join(self.test_dir, 'ntwk_noise.s2p'))
nf = 10**(0.05)
self.assertTrue(a.noisy)
self.assertTrue(
abs(a.nfmin[0] - nf) < 1.e-6,
'noise figure does not match original spec')
self.assertTrue(
abs(a.z_opt[0] - 50.) < 1.e-6,
'optimal resistance does not match original spec')
self.assertTrue(
abs(a.rn[0] - 0.1159 * 50.) < 1.e-6,
'equivalent resistance does not match original spec')
self.assertTrue(
npy.all(abs(a.g_opt) < 1.e-6),
'calculated optimal reflection coefficient does not match original coefficients'
)
b = rf.Network(f=[1, 2], s=[[[0, 1], [1, 0]], [[0, 1], [1, 0]]],
z0=50).interpolate(a.frequency)
with self.assertRaises(ValueError) as context:
b.n
with self.assertRaises(ValueError) as context:
b.f_noise
self.assertEqual(str(context.exception), 'network does not have noise')
c = a**b
self.assertTrue(a.noisy)
self.assertTrue(
abs(c.nfmin[0] - nf) < 1.e-6,
'noise figure does not match original spec')
self.assertTrue(
abs(c.z_opt[0] - 50.) < 1.e-6,
'optimal resistance does not match original spec')
self.assertTrue(
abs(c.rn[0] - 0.1159 * 50.) < 1.e-6,
'equivalent resistance does not match original spec')
d = b**a
self.assertTrue(d.noisy)
self.assertTrue(
abs(d.nfmin[0] - nf) < 1.e-6,
'noise figure does not match original spec')
self.assertTrue(
abs(d.z_opt[0] - 50.) < 1.e-6,
'optimal resistance does not match original spec')
self.assertTrue(
abs(d.rn[0] - 0.1159 * 50.) < 1.e-6,
'equivalent resistance does not match original spec')
e = a**a
self.assertTrue(
abs(e.nfmin[0] - (nf + (nf - 1) / (10**2))) < 1.e-6,
'noise figure does not match Friis formula')
self.assertTrue(a.noisy)
self.assertTrue(
abs(a.nfmin[0] - nf) < 1.e-6, 'noise figure was altered')
self.assertTrue(
abs(a.z_opt[0] - 50.) < 1.e-6, 'optimal resistance was altered')
self.assertTrue(
abs(a.rn[0] - 0.1159 * 50.) < 1.e-6,
'equivalent resistance was altered')
tem = DistributedCircuit(z0=50)
inductor = tem.inductor(1e-9).interpolate(a.frequency)
f = inductor**a
expected_zopt = 50 - 2j * npy.pi * 1e+9 * 1e-9
self.assertTrue(
abs(f.z_opt[0] - expected_zopt) < 1.e-6,
'optimal resistance was not 50 ohms - inductor')
return
def test_s_active(self):
'''
Test the active s-parameters of a 2-ports network
'''
s_ref = self.ntwk1.s
# s_act should be equal to s11 if a = [1,0]
npy.testing.assert_array_almost_equal(
rf.s2s_active(s_ref, [1, 0])[:, 0], s_ref[:, 0, 0])
# s_act should be equal to s22 if a = [0,1]
npy.testing.assert_array_almost_equal(
rf.s2s_active(s_ref, [0, 1])[:, 1], s_ref[:, 1, 1])
# s_act should be equal to s11 if a = [1,0]
npy.testing.assert_array_almost_equal(
self.ntwk1.s_active([1, 0])[:, 0], s_ref[:, 0, 0])
# s_act should be equal to s22 if a = [0,1]
npy.testing.assert_array_almost_equal(
self.ntwk1.s_active([0, 1])[:, 1], s_ref[:, 1, 1])
def test_vswr_active(self):
'''
Test the active vswr-parameters of a 2-ports network
'''
s_ref = self.ntwk1.s
vswr_ref = self.ntwk1.s_vswr
# vswr_act should be equal to vswr11 if a = [1,0]
npy.testing.assert_array_almost_equal(
rf.s2vswr_active(s_ref, [1, 0])[:, 0], vswr_ref[:, 0, 0])
# vswr_act should be equal to vswr22 if a = [0,1]
npy.testing.assert_array_almost_equal(
rf.s2vswr_active(s_ref, [0, 1])[:, 1], vswr_ref[:, 1, 1])
# vswr_act should be equal to vswr11 if a = [1,0]
npy.testing.assert_array_almost_equal(
self.ntwk1.vswr_active([1, 0])[:, 0], vswr_ref[:, 0, 0])
# vswr_act should be equal to vswr22 if a = [0,1]
npy.testing.assert_array_almost_equal(
self.ntwk1.vswr_active([0, 1])[:, 1], vswr_ref[:, 1, 1])
class CPWTestCase(unittest.TestCase):
def setUp(self):
self.files_dir = os.path.join(
os.path.dirname(os.path.abspath(__file__)), 'qucs_prj')
fname = os.path.join(self.files_dir, 'cpw.s2p')
self.qucs_ntwk = rf.Network(fname)
# create various examples
self.freq = rf.Frequency(start=1, stop=20, npoints=21, unit='GHz')
# infinite dielectric substrate, infinitely thin metal
self.cpw1 = CPW(frequency=self.freq, w=40e-6, s=20e-6, ep_r=3)
# infinite GaAs substrate, infinitely thin metal
self.cpw2 = CPW(frequency=self.freq, w=75e-6, s=50e-6, ep_r=12.9)
# infinite GaAs substrate, finite metal thickness
# TODO: not used yet
self.cpw3 = CPW(frequency=self.freq,
w=75e-6,
s=50e-6,
ep_r=12.9,
t=1e-6)
def test_qucs_network(self):
"""
Test against the Qucs project results
TODO : finalize
"""
# create an equivalent skrf network
cpw = CPW(frequency=self.freq,
w=75e-6,
s=50e-6,
ep_r=12.9,
rho=0.22e-6)
ntw = self.cpw2.thru(z0=50)**cpw.line(d=1,
unit='m')**self.cpw2.thru(z0=50)
# self.qucs_ntwk.plot_s_db()
# ntw.plot_s_db()
def test_Z0(self):
"""
Test the CPW Characteristic Impedances
"""
assert_array_almost_equal(self.cpw1.Z0, 85.25, decimal=3)
def test_eps_eff(self):
"""
Test the effective permittivity of CPW
"""
assert_array_almost_equal(self.cpw1.ep_re, 2.00, decimal=3)
assert_array_almost_equal(self.cpw2.ep_re, 6.95, decimal=3)
def test_Z0_vs_f(self):
"""
Test the CPW Characteristic Impedance vs frequency.
Reference data comes from Qucs Documentation (Fig 12.2)
"""
w_over_s_qucs, Z0_qucs = npy.loadtxt(os.path.join(
self.files_dir, 'cpw_qucs_ep_r9dot5.csv'),
delimiter=';',
unpack=True)
w = 1
Z0 = []
for w_o_s in w_over_s_qucs:
_cpw = CPW(frequency=self.freq[0], w=w, s=w / w_o_s, ep_r=9.5)
Z0.append(_cpw.Z0[0].real)
# all to a 3% relative difference
# this is quite a large discrepancy, but I extracted the ref values from the plot
# one could do better eventually by extracting values from Qucs directly
rel_diff = (Z0_qucs - npy.array(Z0)) / Z0_qucs
assert_allclose(rel_diff - 3 / 100, 0, atol=0.1)
