import numpy as np import math import cmath import matplotlib.pyplot as plt im = complex(0.0,1.0) # Si ka = 150.0 ca = 710.0 ra = 2330.0 ta = 150.0e-12 CCa = math.sqrt(ka/(ra*ca*ta)) #Ge kb = 60.0 cb = 310.0 rb = 5300.0 tb = 200.0e-12 CCb = math.sqrt(kb/(rb*cb*tb)) Nf = 1000 fi = 0 ff = 800.0e9 df = (ff-fi)/Nf f = np.zeros(Nf) aux = np.zeros(Nf,dtype=complex) l = 2.0e-9 ###################### fa = 0.5 la = fa*l lb = l-la for cf in range(1,Nf): f[cf]= fi+cf*df w = 2.0*math.pi*f[cf] ga = cmath.sqrt((w*w+im*(w/ta))/(CCa*CCa)) gb = cmath.sqrt((w*w+im*(w/tb))/(CCb*CCb)) na = ka/(1-im*w*ta) nb = kb/(1-im*w*tb) aux1 = cmath.cosh(im*ga*la)*cmath.cosh(im*gb*lb) aux2 = ( (na*ga)/(nb*gb) + (nb*gb)/(na*ga) ) aux3 = cmath.sinh(im*ga*la)*cmath.sinh(im*gb*lb) aux4 = aux1+0.5*aux2*aux3 aux[cf] = cmath.acos(aux4) ######################

Esta es la Fig 3 de este paper
10.1007@s41683-020-00061-2plt.grid() plt.plot(aux.real,f/1e12,'royalblue',3.14+abs(aux.imag),f/1e12,'royalblue') plt.show()