# Chapter 11 : Ac analysis of FEt circuits¶

## Example 11.2, Page No 443¶

In [1]:
import math
#initialisation of variables

Yos=10.0*10**-6
Yfs=3000.0*10**-6
R1=1.0*10**6
R2=5.6*10**6
Rd=2.7*10**3
Rl=Rd

#Calculations
rd=1.0/Yos
Zi=((R1*R2)/(R1+R2))*10**-3
print("input impedance is %dKohm " %Zi)
Zo=(Rd*rd)/(Rd+rd)
print(" output inpedance is %dohm " %Zo)
Av=-Yfs*((Rl*rd)/(Rl+rd))

#Results
print('The value of Av= %.2f ' %(Av))

input impedance is 848Kohm
output inpedance is 2629ohm
The value of Av= -7.89


## Example 11.03, Page No 447¶

In [2]:
import math

#initialisation of variables

Yos=10.0*10**-6
Yfs=4000.0*10**-6
Ig=1.0*10**-9
Vgs=15.0
Rs=3.3*10**3
Rg=1.0*10**6
Rd=4.7*10**3
Rl=33*10**3

#Calculations
rd=1.0/Yos
Rgs=(Vgs/Ig)
Zg=(Rgs*(1+Yfs*Rs))
Zi=Rg
Zd=rd+Rs+(Yfs*Rs*rd)
Zo=(Rd*Zd)/(Rd+Zd)
Av=-(Yfs*((Rd*Rl)/(Rd+Rl)))/(1+Yfs*Rs)
Av=-((Rd*Rl)/(Rd+Rl))/Rs

#Results
print('The value of Av= %.2f ' %(Av))

The value of Av= -1.25


## Example 11.4 Page No 451¶

In [3]:
import math

#initialisation of variables

Yfs=3000.0*10**-6
Rgs=100.0*10**6
rd=50.0*10**3
Rs=5.6*10**3
Rl=12.0*10**3
R1=1.5*10**6
R2=1.0*10**6

#Calculations
Zg=Rgs*(1+Yfs*((Rs*Rl)/(Rs+Rl)))
Zi=(R1*R2)/(R1+R2)
Zs=((1/Yfs)*rd)/((1/Yfs)+rd)
Zo=(Rs*Rl*(1/Yfs))/(Rs*Rl+Rs*(1/Yfs)+Rl*(1/Yfs))
Av=-(Yfs*((Rs*Rl)/(Rs+Rl)))/(1+Yfs*((Rs*Rl)/(Rs+Rl)))

#Results
print('The value of Av= %.2f ' %(Av))

The value of Av= -0.92


## Example 11.5, Page No 456¶

In [4]:
import math
#initialisation of variables

Yfs=3000.0*10**-6
rd=50.0*10**3
Rs=3.3*10**3
Rd=4.7*10**3
Rl=50.0*10**3
rs=600.0

#Calculations
Zs=1/Yfs
Zi=((1/Yfs)*Rs)/((1/Yfs)+Rs)
Zd=rd
Zo=(Rd*rd)/(Rd+rd)
Av=Yfs*((Rd*Rl)/(Rd+Rl))
print("overall volateg gain")
Av=(Yfs*((Rd*Rl)/(Rd+Rl))*Zi)/(rs+Zi)

#Results
print('The value of Av= %.2f ' %(Av))

overall volateg gain
The value of Av= 4.32


## Example 11.6 Page No 459¶

In [5]:
import math
#initialisation of variables
Id=3.0*10**-3
Vds=10.0
Vdd=25.0
Vgs=2.3

#Calculations
Rs=Vgs/Id
Rd=((Vdd-Vds)/Id)-Rs

#Results
print('The value of Rd= %.2f ' %(Rd))

The value of Rd= 4233.33


## Example 11.7 Page No 462¶

In [6]:
import math

#initialisation of variables

Ciss=5.0*10**-12
Yfs=2500.0*10**-6
Yos=75.0*10**-6
Rd=5.6*10**3
Rl=100.0*10**3
R1=3.3*10**6
R2=1.0*10**6
rs=600.0

#Calculations

The input capicitance limited = 18.34