Pythonで回路計算(7)

import numpy as np
import skrf as rf
import matplotlib.pyplot as plt
import scipy

def Calc_Network(FIL1,C11,C21,L11,L12,L21,L22,gnd,port1,port2):
    cnx = [
        [(port1, 0), (L11, 0), (C11, 0)],
        [(C11, 1), (L12, 0), (FIL1, 0)],
        [(FIL1, 1), (L21, 0), (C21, 0)],
        [(C21, 1), (L22, 0), (port2, 0)],
        [(gnd, 0), (L11, 1), (L12, 1), (L21, 1), (L22, 1)]
    ]
    cir = rf.Circuit(cnx)
    ntw = cir.network
    return ntw

FIL1 = rf.Network('out.s2p')
FIL1.name='FIL1'

freq=FIL1.frequency
tl_media = rf.DefinedGammaZ0(freq, z0=50)
gnd = rf.Circuit.Ground(freq, name='gnd')
port1 = rf.Circuit.Port(freq, name='port1', z0=75+75j)
port2 = rf.Circuit.Port(freq, name='port2', z0=50)

C11_def=9e-12
C21_def=9e-12
L11_def=100e-9
L12_def=25e-9
L21_def=25e-9
L22_def=100e-9
x0=(C11_def,C21_def,L11_def,L12_def,L21_def,L22_def)

f_range_lower=314.9e6
f_range_upper=315.1e6
vswr_max=1.5

def matching_network(C11_val,C21_val,L11_val,L12_val,L21_val,L22_val):
    C11 = tl_media.capacitor(C11_val, name='C11')
    C21 = tl_media.capacitor(C21_val, name='C21')
    L11 = tl_media.inductor(L11_val, name='L11')
    L12 = tl_media.inductor(L12_val, name='L12')
    L21 = tl_media.inductor(L21_val, name='L21')
    L22 = tl_media.inductor(L22_val, name='L22')
    ntw=Calc_Network(FIL1,C11,C21,L11,L12,L21,L22,gnd,port1,port2)
    return ntw

def get_err(x):
    ntw=matching_network(*x)
    irange=np.where((ntw.f>=f_range_lower)&(ntw.f<=f_range_upper))
    vswr1=ntw.s_vswr[irange,0,0]
    vswr2=ntw.s_vswr[irange,1,1]
    tgt=np.ones_like(vswr1)*vswr_max
    eval1=vswr1-tgt
    eval2=vswr2-tgt
    err1=np.where(eval1<0,0,eval1)
    err2=np.where(eval2<0,0,eval2)
    return (np.sum(err1)+np.sum(err2))

res=scipy.optimize.fmin(get_err,x0)
print(res)
res=scipy.optimize.fmin(get_err,res)
print(res)
res=scipy.optimize.fmin(get_err,res)
print(res)

#ntw=matching_network(*x0)
ntw=matching_network(*res)

fig=plt.figure()

ax1=fig.add_subplot(2,2,1)
ntw.plot_s_smith(ax=ax1,m=0, n=0, lw=2)

ax2_1=fig.add_subplot(2,2,2)
ax2_2=ax2_1.twinx()
ntw.plot_s_db(ax=ax2_1,m=1, n=0, lw=2, show_legend=False)
ntw.plot_s_vswr(ax=ax2_2,m=0, n=0, lw=2, show_legend=False, color='orangered')
ax2_2.set_ylim(1,6)
handler1, label1 = ax2_1.get_legend_handles_labels()
handler2, label2 = ax2_2.get_legend_handles_labels()
ax2_1.legend(handler1 + handler2, label1 + label2, loc=2, borderaxespad=0.)

ax3=fig.add_subplot(2,2,3)
ntw.plot_s_db(ax=ax3,m=0, n=1, lw=2)

ax4=fig.add_subplot(2,2,4)
ntw.plot_s_smith(ax=ax4,m=1, n=1, lw=2)

fig.tight_layout()
plt.show()