Chapter 9 : Analyzers

Example9_1,pg 501

In [2]:
# variable frequency oscillator

import math
#Variable declaration
fc=1.3*10**6                          #centre frequency
fsignal=1*10**6                       #frequency of the signal
fvfo=0.3*10**6                        #frequency of variable frequency oscillator

#Calculations
per=(fvfo/fc)*100

#Result
print("percent variation:")
print("per = %.2f%%"%(math.floor(per*100)/100))

percent variation:
per = 23.07%

Example9_2,pg 502

In [1]:
# DFT coefficients

import math
#Variable declaration
N=22.0                           #no. of acquistioned data
delt=2*10**-3                    #time period
n=4.0                            #4th DFT coeff.
q=3.0                            #no. of discrete points

#Calculations
#An=(2/N)*V(n)*cos((2*%pi*n*q)/N)
#Bn=(2/N)*V(n)*sin((2*%pi*n*q)/N)

#Result
print("A4=(1/11)V(4)cos(12pi/11)\n")
print("B4=(1/11)V(4)sin(12pi/11)\n")

A4=(1/11)V(4)cos(12pi/11)

B4=(1/11)V(4)sin(12pi/11)

Example9_3,pg 502

In [3]:
# find improvement ratio

import math
#Variable declaration
N=64.0                         #data units
#implimentation steps for DFT=64^2

#Calculations
#for FFT
r= math.log(N,2)/N              #implimentation ratio

#Result
print("implimentation ratio:")
print("r = %.5f or (3/32)"%r)

implimentation ratio:
r = 0.09375 or (3/32)

Example9_4,pg 502

In [8]:
# find distortion factor

import math
#Variable declaration
D3=1.3*10**-2                  #3rd harmonic(unit value)
D5=0.31*10**-2                 #5th harmonic(unit value)
D7=0.04*10**-2                 #7th harmonic(unit value)

#Calculations
Dt=math.sqrt((D3**2)+(D5**2)+(D7**2))

#Result
print("distortion ratio:")
print("Dt = %.5f "%Dt)

distortion ratio:
Dt = 0.01337

Example9_5,pg 502

In [4]:
# find percentage change in feedback
import math
#Variable declaration
Q=10.0                    #Q-factor
m=5.0                     #improvement factor
a=(1.0/((3*Q)-1))         #filter factor


#Calculations
Qr=Q*m                    #rejection Q-factor
ar=(1.0/((3*Qr)-1))       #rejection filter factor
perf=((a-ar)/a)*100       #percent change in feedback

#Result
print("percent change in feedback:")
print("perf = %.2f "%perf)

percent change in feedback:
perf = 80.54

Example9_6,pg 503

In [7]:
# time uncertainity and measurable time

import math
#Variable declaration
fc=100.0*10**6                 #clock frequency
Nm=4.0*10**6                   #memory size

#Calculations
Te=(1.0/fc)                  #timing uncertainity
Tm=(Nm/fc)                   #measurable time

#Result
print("timing uncertainity:")
print("Te = %.f ns\n"%(Te*10**9))
print("measurable time:")
print("Tm = %.f m"%(Tm*10**3))

timing uncertainity:
Te = 10 ns

measurable time:
Tm = 40 m