)
Mesh(
sim=sim,
metal_res=1 / 80,
nonmetal_res=1 / 10,
min_lines=9,
expand_bounds=((0, 0), (0, 0), (10, 40)),
)
sim.run(csx=False)
return np.abs(sim.ports[0].impedance(freq=ref_freq))
# res = optimize_parameter(
# func,
# start=0.25 * trace_width,
# step=0.25 * trace_width,
# tol=0.2,
# max_steps=20,
# display_progress=True,
# )
# print("Minimum ground gap: {}".format(res))
gaps = np.arange(0.5 * trace_width, 3 * trace_width, 0.1 * trace_width)
sim_vals = sweep(func, gaps, processes=11)
norm_gaps = gaps / trace_width
print_table(data=[norm_gaps, sim_vals], col_names=["gap", "z0"], prec=[4, 4])
radius=coax_rad,
core_radius=core_rad,
shield_thickness=mil_to_mm(5),
dielectric=coax_dielectric,
propagation_axis=Axis("x", direction=-1),
port_number=2,
ref_impedance=50,
)
mesh = Mesh(
sim=sim,
metal_res=1 / 120,
nonmetal_res=1 / 10,
min_lines=5,
expand_bounds=((0, 0), (0, 0), (20, 20)),
)
box = mesh.sim_box(include_pml=False)
field = FieldDump(sim=sim, box=box, dump_type=DumpType.efield_time)
sim.run()
sim.view_field()
s11 = sim.s_param(1, 1)
s21 = sim.s_param(2, 1)
print_table(
data=[sim.freq / 1e9, s11, s21],
col_names=["freq", "s11", "s21"],
prec=[4, 4, 4],
)
dump = FieldDump(
sim=sim,
box=Box3(
Coordinate3(-pcb_len / 2, -pcb_width / 2, 0),
Coordinate3(pcb_len / 2, pcb_width / 2, 0),
),
)
mesh = Mesh(
sim=sim,
metal_res=1 / 120,
nonmetal_res=1 / 40,
smooth=(1.1, 1.5, 1.5),
min_lines=25,
expand_bounds=((0, 0), (24, 24), (24, 24)),
)
if os.getenv("_PYEMS_PYTEST"):
sys.exit(0)
sim.run()
sim.view_field()
print_table(
data=[sim.freq / 1e9,
np.abs(sim.ports[0].impedance()),
sim.s_param(1, 1)],
col_names=["freq", "z0", "s11"],
prec=[4, 4, 4],
)
layers=range(3),
)
Microstrip(
pcb=pcb,
position=Coordinate2(0, 0),
length=pcb_len,
width=trace_width,
propagation_axis=Axis("x"),
gnd_gap=(gnd_gap, gnd_gap),
port_number=1,
excite=True,
ref_impedance=50,
)
Mesh(
sim=sim,
metal_res=1 / 80,
nonmetal_res=1 / 10,
min_lines=9,
expand_bounds=((0, 0), (0, 0), (10, 40)),
)
sim.run()
print_table(
data=[freq / 1e9, np.abs(sim.ports[0].impedance())],
col_names=["freq", "z0"],
prec=[2, 4],
)
def func(params: List[float]):
"""
"""
cutout_width = params[0]
sim = Simulation(freq=freq, unit=unit, sim_dir=None)
pcb = PCB(
sim=sim,
pcb_prop=pcb_prop,
length=pcb_len,
width=pcb_width,
layers=range(3),
omit_copper=[0],
)
box = Box2(
Coordinate2(-pcb_len / 2, -trace_width / 2),
Coordinate2(-(cap_dim.length / 2) - (pad_length / 2), trace_width / 2),
)
Microstrip(
pcb=pcb,
position=box.center(),
length=box.length(),
width=box.width(),
propagation_axis=Axis("x"),
trace_layer=0,
gnd_layer=1,
port_number=1,
excite=True,
feed_shift=0.35,
ref_impedance=z0_ref,
)
SMDPassive(
pcb=pcb,
position=Coordinate2(0, 0),
axis=Axis("x"),
dimensions=cap_dim,
pad_width=pad_width,
pad_length=pad_length,
c=10e-12,
pcb_layer=0,
gnd_cutout_width=cutout_width,
gnd_cutout_length=1,
)
box = Box2(
Coordinate2(pcb_len / 2, trace_width / 2),
Coordinate2((cap_dim.length / 2) + (pad_length / 2), -trace_width / 2),
)
Microstrip(
pcb=pcb,
position=box.center(),
length=box.length(),
width=box.width(),
propagation_axis=Axis("x", direction=-1),
trace_layer=0,
gnd_layer=1,
port_number=2,
excite=False,
ref_impedance=z0_ref,
)
Mesh(
sim=sim,
metal_res=1 / 120,
nonmetal_res=1 / 40,
smooth=(1.2, 1.2, 1.2),
min_lines=5,
expand_bounds=((0, 0), (0, 0), (10, 20)),
)
sim.run(csx=False)
print_table(
data=[sim.freq / 1e9, sim.s_param(1, 1), sim.s_param(2, 1)],
col_names=["freq", "s11", "s21"],
prec=[4, 4, 4],
)
return np.sum(sim.s_param(1, 1))
min_lines=5,
expand_bounds=((16, 16), (16, 16), (8, 24)),
)
field_dump = FieldDump(sim=sim, box=mesh.sim_box(include_pml=False))
nf2ff = NF2FF(sim=sim)
if os.getenv("_PYEMS_PYTEST"):
sys.exit(0)
sim.run()
sim.view_field()
s11 = sim.s_param(1, 1)
print_table(
np.concatenate(([sim.freq / 1e9], [s11])),
col_names=["freq", "s11"],
prec=[4, 4],
)
theta = np.arange(-90, 90, 1)
phi = np.arange(0, 360, 1)
nf2ff.calc(theta=theta, phi=phi)
horn_width = 109.9e-3
horn_height = 80e-3
effective_aperture = horn_height * horn_width
print(nf2ff.directivity(effective_aperture))
print("gain: {:.2f} dB".format(nf2ff.gain()))
rad_phi0 = nf2ff.radiation_pattern(phi=0)
mesh = Mesh(
sim=sim,
metal_res=1 / 80,
nonmetal_res=1 / 40,
smooth=(1.1, 1.5, 1.5),
min_lines=5,
expand_bounds=((0, 0), (8, 8), (8, 8)),
)
# mesh.add_line_manual(0, -cap_dim.length / 2)
# mesh.add_line_manual(0, cap_dim.length / 2)
FieldDump(
sim=sim,
box=Box3(
Coordinate3(-pcb_len / 2, -pcb_width / 2, 0),
Coordinate3(pcb_len / 2, pcb_width / 2, 0),
),
dump_type=DumpType.current_density_time,
)
sim.run()
sim.view_field()
print_table(
data=[sim.freq / 1e9, sim.s_param(1, 1), sim.s_param(2, 1)],
col_names=["freq", "s11", "s21"],
prec=[2, 4, 4],
)
propagation_axis=Axis("x", direction=-1),
trace_layer=0,
gnd_layer=1,
port_number=2,
ref_impedance=50,
)
Mesh(
sim=sim,
metal_res=1 / 120,
nonmetal_res=1 / 40,
min_lines=5,
expand_bounds=((0, 0), (0, 0), (10, 40)),
)
# sim.run(csx=False)
sim.run()
return sim.s_param(1, 1)
angles = np.arange(10, 90, 10)
angles = [10]
res = sweep(sim_func, angles, processes=5)
str_angles = [str(angle) for angle in angles]
print_table(
data=np.concatenate(([freq / 1e9], res)),
col_names=["freq"] + str_angles,
prec=[2] + [4 for _ in angles],
)
def optimize_parameter(func,
start,
step,
tol,
max_steps,
display_progress=False):
"""
Compute the lowest-cost value of a parameter that still produces
accurate results.
"""
res1 = func(start)
n = len(res1)
res_matrix = np.zeros((max_steps, n), dtype=np.clongdouble)
res_matrix[0] = np.array(res1)
# compute the root mean square differences from the previous results array.
rms = np.zeros((max_steps - 1, ))
# If the first few RMS values don't show a clear trend, ignore
# them, since this may have been the result of poor start value
# choice.
rms_trend_down = False
rms_valid_index = 0
i = 1
orig_start = start
start += step
while i < max_steps:
res_matrix[i] = np.array(func(start))
diff = np.subtract(res_matrix[i], res_matrix[i - 1])
rms[i - 1] = np.sqrt(
np.sum(np.real(np.multiply(diff, np.conj(diff)))) / n)
if display_progress:
num_steps = int(np.round((start - orig_start) / step) + 1)
print_table(
np.abs(res_matrix[:i + 1]),
[
"{:.4f}".format(val)
for val in np.linspace(orig_start, start, num=num_steps)
],
[4 for _ in range(num_steps)],
)
print("parameter: {}".format(start))
print("RMS: {:.10f}".format(rms[i - 1]))
if not rms_trend_down and i > 1 and rms[i - 1] > rms[i - 2]:
rms_valid_index = i - 1
if i - rms_valid_index > 2:
if (not rms_trend_down and rms[i - 1] < rms[i - 2]
and rms[i - 2] < rms[i - 3]):
rms_trend_down = True
valid_start = orig_start + (rms_valid_index * step)
num_valid_steps = int(
np.round((start - step - valid_start) / step) + 1)
try:
print(
np.linspace(valid_start, start - step,
num=num_valid_steps))
print(rms[rms_valid_index:i])
fit = curve_fit(
rms_fit,
np.linspace(valid_start, start - step,
num=num_valid_steps),
rms[rms_valid_index:i],
)
a = fit[0][0]
b = fit[0][1]
error_estimate = rms_remaining_sum(a, b, start + 1)
if display_progress:
print("Error estimate: {:.10f}".format(error_estimate))
if error_estimate < tol:
return start
except RuntimeError:
# If curve fitting fails, ignore the oldest RMS value
# and try again on the next iteration.
print(
"Failed to fit curve to RMS values, ignoring oldest value."
)
rms_valid_index += 1
i += 1
start += step
raise RuntimeError("Failed to optimize parameter. Consider increasing "
"the tolerance or max number of steps.")
shield_thickness=mil_to_mm(5),
dielectric=dielectric,
propagation_axis=Axis("x"),
port_number=1,
excite=True,
feed_shift=0.3,
ref_impedance=50,
)
mesh = Mesh(
sim=sim,
metal_res=1 / 40,
nonmetal_res=1 / 10,
min_lines=9,
expand_bounds=((0, 0), (8, 8), (8, 8)),
)
box = mesh.sim_box(include_pml=False)
field = FieldDump(sim=sim, box=box, dump_type=DumpType.efield_time)
sim.run()
sim.view_field()
z0 = sim.ports[0].impedance()
s11 = sim.s_param(1, 1)
print_table(
data=[sim.freq / 1e9, np.abs(z0), s11],
col_names=["freq", "z0", "s11"],
prec=[4, 4, 4],
)
Mesh(
sim=sim,
metal_res=1 / 80,
nonmetal_res=1 / 10,
min_lines=9,
expand_bounds=((0, 0), (0, 0), (10, 40)),
)
FieldDump(
sim=sim,
box=Box3(
Coordinate3(-pcb_len / 2, -pcb_width / 2, 0),
Coordinate3(pcb_len / 2, pcb_width / 2, 0),
),
dump_type=DumpType.current_density_time,
)
sim.run(csx=False)
return np.abs(sim.ports[0].impedance(freq=ref_freq))
widths = np.arange(0.75 * mid_width, 1.25 * mid_width, 0.05 * mid_width)
sim_vals = sweep(func, widths, processes=11)
print_table(
data=[widths, sim_vals],
col_names=["width", "z0"],
prec=[4, 4],
)
def sim_func(cutout_width: float):
"""
"""
sim = Simulation(freq=freq, unit=unit, reference_frequency=ref_freq)
core_rad = (coax_core_diameter(
2 * coax_rad, coax_dielectric.epsr_at_freq(sim.reference_frequency)) /
2)
pcb_prop = common_pcbs["oshpark4"]
pcb = PCB(
sim=sim,
pcb_prop=pcb_prop,
length=pcb_len,
width=pcb_width,
layers=range(3),
omit_copper=[0],
)
Microstrip(
pcb=pcb,
position=Coordinate2(0, 0),
length=pcb_len,
width=trace_width,
propagation_axis=Axis("x"),
trace_layer=0,
gnd_layer=1,
port_number=1,
ref_impedance=50,
excite=True,
)
# Mueller BU-1420701851 edge mount SMA
pad = sim.csx.AddConductingSheet(
"pad",
conductivity=pcb_prop.metal_conductivity(),
thickness=pcb_prop.copper_thickness(0),
)
pad.AddBox(
priority=priorities["trace"],
start=[pcb_len / 2 - sma_lead_len / 2, -sma_lead_width / 2, 0],
stop=[pcb_len / 2, sma_lead_width / 2, 0],
)
pad_cutout = sim.csx.AddMaterial(
"gnd_cutout",
epsilon=pcb_prop.substrate.epsr_at_freq(ref_freq),
kappa=pcb_prop.substrate.kappa_at_freq(ref_freq),
)
pad_cutout.AddBox(
priority=priorities["keepout"],
start=[
pcb_len / 2 - sma_lead_len / 2,
-cutout_width / 2,
pcb.copper_layer_elevation(1),
],
stop=[pcb_len / 2, cutout_width / 2,
pcb.copper_layer_elevation(1)],
)
sma_box = sim.csx.AddMetal("sma_box")
sma_box.AddBox(
priority=priorities["ground"],
start=[
pcb_len / 2,
-sma_rect_width / 2,
-sma_rect_height / 2 + sma_lead_height / 2,
],
stop=[
pcb_len / 2 + sma_rect_length,
sma_rect_width / 2,
sma_rect_height / 2 + sma_lead_height / 2,
],
)
sma_keepout = sim.csx.AddMaterial(
"sma_keepout",
epsilon=coax_dielectric.epsr_at_freq(ref_freq),
kappa=coax_dielectric.kappa_at_freq(ref_freq),
)
sma_keepout.AddCylinder(
priority=priorities["keepout"],
start=[pcb_len / 2, 0, sma_lead_height / 2],
stop=[pcb_len / 2 + sma_rect_length, 0, sma_lead_height / 2],
radius=coax_rad,
)
for ypos in [
-sma_rect_width / 2,
sma_rect_width / 2 - sma_gnd_prong_width,
]:
# sma_box.AddBox(
# priority=priorities["ground"],
# start=[pcb_len / 2 - sma_gnd_prong_len, ypos, 0],
# stop=[
# pcb_len / 2,
# ypos + sma_gnd_prong_width,
# sma_gnd_prong_height
# ],
# )
# sma_box.AddBox(
# priority=priorities["ground"],
# start=[
# pcb_len / 2 - sma_gnd_prong_len,
# ypos,
# pcb.copper_layer_elevation(1)
# ],
# stop=[
# pcb_len / 2,
# ypos + sma_gnd_prong_width,
# pcb.copper_layer_elevation(1) - sma_gnd_prong_height,
# ],
# )
sma_box.AddBox(
priority=priorities["ground"],
start=[
pcb_len / 2 - sma_gnd_prong_len,
ypos,
pcb.copper_layer_elevation(1) - sma_gnd_prong_height,
],
stop=[
pcb_len / 2,
ypos + sma_gnd_prong_width,
sma_gnd_prong_height,
],
)
lead = sim.csx.AddMetal("lead")
lead.AddBox(
priority=priorities["trace"],
start=[pcb_len / 2 - sma_lead_len / 2, -sma_lead_width / 2, 0],
stop=[
pcb_len / 2 + sma_rect_length,
sma_lead_width / 2,
sma_lead_height,
],
)
# coax port
Coax(
sim=sim,
position=Coordinate3(
pcb_len / 2 + sma_rect_length + coax_len / 2,
0,
sma_lead_height / 2,
),
length=coax_len,
radius=coax_rad,
core_radius=core_rad,
shield_thickness=mil_to_mm(5),
dielectric=coax_dielectric,
propagation_axis=Axis("x", direction=-1),
port_number=2,
ref_impedance=50,
)
mesh = Mesh(
sim=sim,
metal_res=1 / 120,
nonmetal_res=1 / 10,
min_lines=5,
expand_bounds=((0, 0), (0, 0), (10, 10)),
)
box = mesh.sim_box(include_pml=False)
sim.run(csx=False)
s11 = sim.s_param(1, 1)
s21 = sim.s_param(2, 1)
print("cutout width: {}".format(cutout_width))
print_table(
data=[sim.freq / 1e9, s11, s21],
col_names=["freq", "s11", "s21"],
prec=[4, 4, 4],
)
return np.sum(s11)
