def test_abcd_lossy_line(self):
'''
Lossy transmission line of characteristic impedance Z0, length l
and propagation constant gamma = alpha + j beta
○---------○
○---------○
has ABCD matrix of the form:
[ cosh(gamma l) Z0 sinh(gamma l) ]
[ 1/Z0 sinh(gamma l) cosh(gamma l) ]
'''
l = 5.0
z0 = 30.0
alpha = 0.5
beta = 2.0
lossy_media = DefinedGammaZ0(frequency=Frequency(1, 100, 21, 'GHz'),
gamma=alpha + 1j * beta,
z0=z0)
ntw = lossy_media.line(d=l, unit='m', z0=z0)
gamma = lossy_media.gamma
npy.testing.assert_array_almost_equal(ntw.a[:, 0, 0],
npy.cosh(gamma * l))
npy.testing.assert_array_almost_equal(ntw.a[:, 0, 1],
z0 * npy.sinh(gamma * l))
npy.testing.assert_array_almost_equal(ntw.a[:, 1, 0],
1.0 / z0 * npy.sinh(gamma * l))
npy.testing.assert_array_almost_equal(ntw.a[:, 1, 1],
npy.cosh(gamma * l))
def setUp(self):
self.files_dir = os.path.join(
os.path.dirname(os.path.abspath(__file__)), 'qucs_prj')
self.dummy_media = DefinedGammaZ0(
frequency=Frequency(1, 100, 21, 'ghz'),
gamma=1j,
z0=50,
)
def test_complex_ports(self):
m = DefinedGammaZ0(
frequency=Frequency(1, 1, 1, 'ghz'),
gamma=1j,
z0=50,
Z0=10 + 20j,
)
self.assertTrue(m.Z0.imag != 0)
# Powerwave short is -Z0.conj()/Z0
short = m.short(z0=m.Z0, s_def='power')
self.assertTrue(short.s != -1)
# Should be -1 when converted to traveling s_def
npy.testing.assert_allclose(short.s_traveling, -1)
short = m.short(z0=m.Z0, s_def='traveling')
npy.testing.assert_allclose(short.s, -1)
short = m.short(z0=m.Z0, s_def='pseudo')
npy.testing.assert_allclose(short.s, -1)
# Mismatches agree with real port impedances
mismatch_traveling = m.impedance_mismatch(z1=10,
z2=50,
s_def='traveling')
mismatch_pseudo = m.impedance_mismatch(z1=10, z2=50, s_def='pseudo')
mismatch_power = m.impedance_mismatch(z1=10, z2=50, s_def='power')
npy.testing.assert_allclose(mismatch_traveling.s, mismatch_pseudo.s)
npy.testing.assert_allclose(mismatch_traveling.s, mismatch_power.s)
mismatch_traveling = m.impedance_mismatch(z1=10 + 10j,
z2=50 - 20j,
s_def='traveling')
mismatch_pseudo = m.impedance_mismatch(z1=10 + 10j,
z2=50 - 20j,
s_def='pseudo')
mismatch_power = m.impedance_mismatch(z1=10 + 10j,
z2=50 - 20j,
s_def='power')
# Converting thru to new impedance should give impedance mismatch.
# The problem is that thru Z-parameters have infinities
# and renormalization goes through Z-parameters making
# it very inaccurate.
thru_traveling = m.thru(s_def='traveling')
thru_traveling.renormalize(z_new=[10 + 10j, 50 - 20j])
thru_pseudo = m.thru(s_def='pseudo')
thru_pseudo.renormalize(z_new=[10 + 10j, 50 - 20j])
thru_power = m.thru(s_def='power')
thru_power.renormalize(z_new=[10 + 10j, 50 - 20j])
npy.testing.assert_allclose(thru_traveling.s,
mismatch_traveling.s,
rtol=1e-3)
npy.testing.assert_allclose(thru_pseudo.s,
mismatch_pseudo.s,
rtol=1e-3)
npy.testing.assert_allclose(thru_power.s, mismatch_power.s, rtol=1e-3)
def test_scalar_gamma_z0_media(self):
"""
test ability to create a Media from scalar quantities for gamma/z0
"""
freq = Frequency(1, 10, 101)
a = DefinedGammaZ0(freq, gamma=1j, z0=50)
self.assertEqual(len(freq), len(a))
self.assertEqual(len(freq), len(a.gamma))
self.assertEqual(len(freq), len(a.z0))
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_alpha_warning(self):
"""
Test if warns when t < 3 * skin_depth
"""
freq = Frequency(1, 1, 1, 'MHz')
with self.assertWarns(RuntimeWarning) as context:
mline = MLine(frequency = freq, z0 = 50.,
w = self.w, h = self.h, t = self.t,
ep_r = self.ep_r, rho = self.rho,
tand = self.tand, rough = self.d,
diel = 'frequencyinvariant', disp = 'hammerstadjensen')
def test_scalar_gamma_z0_media(self):
'''
test ability to create a Media from scalar quanties for gamma/z0
and change frequency resolution
'''
a = DefinedGammaZ0(Frequency(1, 10, 101), gamma=1j, z0=50)
self.assertEqual(a.line(1), a.line(1))
# we should be able to re-sample the media
a.npoints = 21
self.assertEqual(len(a.gamma), len(a))
self.assertEqual(len(a.z0), len(a))
self.assertEqual(len(a.z0), len(a))
def test_vector_gamma_z0_media(self):
"""
test ability to create a Media from vector quantities for gamma/z0
"""
freq = Frequency(1, 10, 101)
a = DefinedGammaZ0(
freq,
gamma=1j * npy.ones(len(freq)),
z0=50 * npy.ones(len(freq)),
)
self.assertEqual(len(freq), len(a))
self.assertEqual(len(freq), len(a.gamma))
self.assertEqual(len(freq), len(a.z0))
def test_vector_gamma_z0_media(self):
'''
test ability to create a Media from vector quanties for gamma/z0
'''
freq = Frequency(1, 10, 101)
a = DefinedGammaZ0(
freq,
gamma=1j * npy.ones(len(freq)),
z0=50 * npy.ones(len(freq)),
)
self.assertEqual(a.line(1), a.line(1))
with self.assertRaises(NotImplementedError):
a.npoints = 4
def test_Z0_ep_reff(self):
"""
Test against characterisitc impedance from another calculator using
Hammerstadt-Jensen model
http://web.mit.edu/~geda/arch/i386_rhel3/versions/20050830/html/mcalc-1.5/
"""
freq = Frequency(1, 1, 1, 'GHz')
mline1 = MLine(frequency = freq, z0 = 50.,
w = self.w, h = self.h, t = self.t,
ep_r = self.ep_r, rho = self.rho,
tand = self.tand, rough = self.d,
diel = 'frequencyinvariant', disp = 'hammerstadjensen',
compatibility_mode = 'qucs')
# without t (t = None)
mline2 = MLine(frequency = freq, z0 = 50.,
w = self.w, h = self.h,
ep_r = self.ep_r, rho = self.rho,
tand = self.tand, rough = self.d,
diel = 'frequencyinvariant', disp = 'hammerstadjensen',
compatibility_mode = 'qucs')
# with t = 0
mline3 = MLine(frequency = freq, z0 = 50.,
w = self.w, h = self.h, t = 0,
ep_r = self.ep_r, rho = self.rho,
tand = self.tand, rough = self.d,
diel = 'frequencyinvariant', disp = 'hammerstadjensen',
compatibility_mode = 'qucs')
self.assertTrue(npy.abs((mline1.Z0[0] - 49.142) / 49.142) < 0.01)
self.assertTrue(npy.abs((mline1.ep_reff_f[0] - 3.324) / 3.324) < 0.01)
self.assertTrue(npy.abs(mline2.w_eff - mline2.w) < 1e-16)
self.assertTrue(npy.abs(mline2.alpha_conductor) < 1e-16)
self.assertTrue(npy.abs(mline3.w_eff - mline3.w) < 1e-16)
self.assertTrue(npy.abs(mline3.alpha_conductor) < 1e-16)
def setUp(self):
self.dummy_media = DefinedGammaZ0(
frequency=Frequency(1, 100, 21, 'GHz'),
gamma=1j,
z0=50,
)