# Chapter 6 Aperture and Lens Antenna¶

## 6.1 Directive gain calculation¶

In [3]:
from __future__ import division
import math

#horn antenna
Ae=10;
del_a=0.2;
p=Ae**2/(8*del_a);
del1=0.375;
Thetae=2*math.atan((Ae/(2*p)))*180/(math.pi); #flare angle
Thetah=2*math.acos(p/(p+del1))*180/(math.pi);
Ah=2*p*math.tan(((Thetah*(math.pi)/180)/2));
print("The length is %g m"%p);
print("The angle ThetaE is %g degree"%Thetae);
print("The angle ThetaH is %g degree"%Thetah);
print("The H plane aperture is %g"%Ah);
HPBWH=67/Ah;
HPBWE=56/Ae;
Ddb=10*math.log10((7.5*Ae*Ah));
print('\n')
print("The HPBWE is %g degree"%HPBWE);
print("The HPBWH is %g degree"%HPBWH);
print("The Directive gain in db is %g db"%Ddb);

The length is 62.5 m
The angle ThetaE is 9.14784 degree
The angle ThetaH is 12.5216 degree
The H plane aperture is 13.7136

The HPBWE is 5.6 degree
The HPBWH is 4.88567 degree
The Directive gain in db is 30.1221 db


## 6.2 Effective aperture calculation¶

In [4]:
from __future__ import division
import math

#parabolic reflector antenna
BWFN=10;
f=3*10**9;
c=3*10**8;
lamda=c/f;
d=140*lamda/(BWFN);
print("The diameter d is %g m"%d);
#For circular parabolidal antenna
Ae=((math.pi)*(d**2))/4;
print("The effective aperture is %g m^2"%Ae);

The diameter d is 1.4 m
The effective aperture is 1.53938 m^2