"""
Adapter models that store static RF network data.
"""
import skrf
import jax.numpy as jnp
from pmrf.models.adapters.base import Model
from pmrf.frequency import Frequency
from pmrf.field import field
[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.
"""
network: skrf.Network = field(static=True)
def __post_init__(self):
self.network.renormalize(self.z0, 'power')
[docs]
def s(self, freq: Frequency) -> jnp.ndarray:
S_old = jnp.array(self.network.s)
f_old = jnp.array(self.network.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