44 lines
1.1 KiB
Python
44 lines
1.1 KiB
Python
#!/usr/bin/pyhton3
|
|
|
|
### 11. 2. 21 - v izpeljavo (14) vstavim meritev
|
|
# P0 pomerjen na fotodiodi???
|
|
# N0 na fotodiodi
|
|
|
|
import numpy as np
|
|
import matplotlib.pyplot as plt
|
|
|
|
|
|
|
|
db2lin = lambda x: 10**(x/10)
|
|
# nepotrebne velicine
|
|
#T0 = 290 # sobna temperatura [K]
|
|
#Tel = 3.55e7 # pomerjena elektricna temperatura [K]
|
|
#kB = 1.38e-23 #boltzmannova konstanta
|
|
#F = 10**(2.5/10) # sumno stevilo v linearnih enotah
|
|
Q = 2100 # kvaliteta resonatorja
|
|
#Toe = 1e5 #temperatura linije [K] - vzel iz Matjazeve skripte
|
|
f0 = 10.5e9 # frekvenca nosilca [Hz]
|
|
tau = 1022*1.4676/3e8 #zakasnitev linije [s]
|
|
|
|
Pc = db2lin(-3.6-25)
|
|
N0 = db2lin(-120.41)
|
|
|
|
|
|
def L(df, Pc, N0):
|
|
# prva izpeljava: enacba (14)
|
|
L = 0.5 * N0/Pc
|
|
L *= np.abs(1-np.exp(-2j*np.pi*tau*df)/(1+2j*Q*df/f0))**-2
|
|
return 10*np.log10(L)
|
|
|
|
df = np.linspace(1e2, 1e5, 1e5)
|
|
plt.figure()
|
|
plt.semilogx(df,L(df,Pc, N0),'c') # Pc = -30 dBm izhod za fotodiode
|
|
plt.xlabel("Frekvenčni odmik [Hz]")
|
|
plt.ylabel("Spektralna gostota šuma [dBc/Hz]")
|
|
plt.grid(True)
|
|
#plt.savefig("dve-enacbi.png")
|
|
plt.show()
|
|
|
|
data = np.column_stack((df, L(df,Pc,N0)))
|
|
np.savetxt("analitika.csv", data, delimiter=',')
|