import numpy as np
import matplotlib.pyplot as plt

##
f = np.array([...])
U_e = np.array([...])
U_s = np.array([...])
Delta_t = np.array([...])


##
G_dB = 20*np.log10(U_s/U_e)
phi = -2*np.pi*Delta_t*f

##
plt.close('all')
plt.figure('Diagramme de Bode', figsize = [16/2.54, 20/2.54])
plt.axes([0.18, 0.55, 0.8, 0.44])
plt.semilogx(f, G_dB, 'rs', markeredgecolor = 'k', ms = 6 )
plt.ylabel(r'$G_dB}$', fontsize = 12)
plt.xlim([np.min(f), np.max(f)])

plt.axes([0.18, 0.1, 0.8, 0.44])
plt.semilogx(f, phi, 'rs', markeredgecolor = 'k', ms = 6 )
plt.ylabel(r'$\arg(\varphi)\,{(\rm rad)}$', fontsize = 12)
plt.xlabel(r'$F,{\rm (Hz)}$')
plt.xlim([np.min(f), np.max(f)])
plt.show()