Chapter 10: Travelling Wave and Broadband Antennas

Example 10.1, Page no. 573

In [1]:
#Given example parameters have to be found in terms of lambda, we assume lamda = 50
lamda0=50
N=10.0

C=lamda0
print "Circumference:",C

alpha=13
print "Optimum pitch angle:",alpha

S=C*tan(alpha*pi/180)
print "Seperation between turns:",S

L0=sqrt(S**2+C**2)
print "Length of single turn:",L0

vh=L0/lamda0
v0=(S/lamda0)+1
p_end=vh/v0
print "Relative wave velocity of ordinary end-fire antenna:",p_end

p_wood=vh/((S/lamda0)+((2*N+1)/(2*N)))
print "Relative wave velocity of Hansen-Woodyard end-fire antenna:",p_wood

HPBW=((52*lamda0)**(1.5))/(C*sqrt(N*S))
print "Half-power Beamwidth:",HPBW

D0=15*N*C**2*S/lamda0**3
print "Directivity:",10*log10(D0),"dB"

AR=(2*N+1)/(2*N)
print "Axial Ratio:",10*log10(AR)
Circumference: 50
Optimum pitch angle: 13
Seperation between turns: 11.5434095563
Length of single turn: 51.3152053897
Relative wave velocity of ordinary end-fire antenna: 0.833805045246
Relative wave velocity of Hansen-Woodyard end-fire antenna: 0.801256612432
Half-power Beamwidth: 246.787390223
Directivity: 15.3945535927 dB
Axial Ratio: 0.211892990699