"""
Adapter models that store static RF network data.
"""
import skrf
import jax.numpy as jnp
import parax as prx
from pmrf.core import Model, Frequency
from pmrf.network_collection import NetworkCollection
[docs]
class Measured(Model):
"""
A model wrapping a static Measured Network (e.g., from a Touchstone file).
This model takes a `skrf.Network` and interpolates its S-parameters to the
frequency grid requested during simulation.
Attributes
----------
network : skrf.Network
The static network data containing S-parameters and frequency information.
Marked as static to avoid tracing overhead in JAX.
"""
data: skrf.Network | NetworkCollection = prx.field(static=True)
def __getattr__(self, name: str) -> 'Measured':
data = self.__getattribute__('data')
if isinstance(data, NetworkCollection) and name in data.to_dict():
return Measured(data[name])
return super().__getattr__(name)
def __post_init__(self):
self.data.renormalize(self.z0, 'power')
[docs]
def s(self, freq: Frequency) -> jnp.ndarray:
if isinstance(self.data, NetworkCollection):
raise Exception("Cannot call s() on a Measured model that contains a NetworkCollection")
S_old = jnp.array(self.data.s)
f_old = jnp.array(self.data.f)
f_new = freq.f
n_ports = S_old.shape[1]
# Split into real and imaginary parts
S_real = jnp.real(S_old)
S_imag = jnp.imag(S_old)
# Interpolate each real/imag component independently
def interp_component(S_comp):
return jnp.stack([
jnp.stack([
jnp.interp(f_new, f_old, S_comp[:, i, j], left=jnp.nan, right=jnp.nan)
for j in range(n_ports)
], axis=0)
for i in range(n_ports)
], axis=0) # shape: (n_ports, n_ports, n_freqs_new)
S_real_new = interp_component(S_real)
S_imag_new = interp_component(S_imag)
# Combine and transpose back to (n_freqs_new, n_ports, n_ports)
S_new = (S_real_new + 1j * S_imag_new).transpose(2, 0, 1)
return S_new