Chapter8 Amplitude Modulation

Example 8.3.1,Pg.no.257

In [5]:
import math
from math import pi,sqrt
vpp=11.0    #peak to peak voltage of modulating signal
vcp=10.0    #carrier peak voltage
#Determination of modulation index
E_max=vcp+(vpp/2)
E_min=vcp-(vpp/2)
m=(E_max -E_min)/(E_max+E_min)
print 'The modulation index is',m
#determination of k ratio of side lengths
L1_L2=E_max/E_min
L1_L2=round(L1_L2,2)
print 'The ratio of side lengths L1/L2 is',L1_L2

The modulation index is 0.55
The ratio of side lengths L1/L2 is 3.44

Example 8.5.1,Pg.no.260

In [6]:
import math
fc=10*10**6      #Carrier freq
fm=5*10**3       #Modullating freq
vp=10.0
vm=6.0          #Determination of modulation index
m=vm/vp
m=round(m,1)
print 'The modulation index is',m

The modulation index is 0.6

Example 8.7.1,Pg.no.263

In [7]:
import math
from math import sqrt
I=12.0
Ic=10.0     
#Determination of modulation index
m=sqrt(2*(((I/Ic)**2) -1))
m=round(m,1)
print 'The modulation index is',m

The modulation index is 0.9

Example 8.11.1,Pg.no.274

In [8]:
import math
from math import sqrt,pi
fm=10*10**3           #modulation freq
c=1000*10**-12
R=10*10**3
Yp=complex((1/R),(2*(pi)*fm*c))   #admittance of RC load
Ypi=Yp.imag*10**5
Ypi=round(Ypi,2)*10**-5
print 'Yp=',Ypi,'j'
Zp=1/sqrt(((Yp.real)**2)+((Yp.imag)**2))
Zp=round(Zp,1)
print 'Zp=',Zp
#Determination of max modulation index
m=Zp/R
m=round(m,2)
print 'The max modulation index is',m

Yp= 6.28e-05 j
Zp= 15915.5
The max modulation index is 1.59