Chapter 4. Linear Wire Antennas

Example 4.1, Page 156

#lambda is very small
lamda=0.0001

#Length of infinitesimal dipole
l=lamda/50

#Calculation of radiation resistance
R_r=80*(pi**2)*(l/lamda)**2

print 'Radiation resisitance:',R_r,'Ohms'

Radiation resisitance: 0.315827340835

Example 4.3, Page 168

#Lamda is a variable value in this example and therefore we will write a function to calculate the differences by passing different values of lambda

def phase_diff(z,r,lamda):
    R1=sqrt(z**2+r**2)
    R2=r
    phase_diff=(2*pi/lamda)*(R1-R2)
    print 'The phase difference is:',phase_diff,'radians.'
    
    
def amp_diff(z,r,lamda):
    R1=sqrt(z**2+r**2)
    R2=r
    amp_diff=(1/R1)-(1/R2)
    print 'The amplitude difference is:',amp_diff
    
#We will assume lamda = 50
lamda=50

#Given
l=5*lamda
r=60*lamda

#z=2.5lamda at 90 degree
z=2.5*lamda

phase_diff(z,r,lamda)
amp_diff(z,r,lamda)

The phase difference is: 0.327107322652 radians.
The amplitude difference is: 0.000333044357697

Example 4.4, Page 194

#Given is the input resistance of dipole
R=50

#Calculation of gain G
G=pow(float(R)/24.7,1/2.5)

print G

1.32589526731