Hello, I am trying to plot radiation intensity of antenna using the following code but i am not getting polar plots with theta axis and polar, grids please help me. help me

i resolved the problem but i am not getting polar plots in degree co-orditanates. can any body please help me . I have attached the graph and here is my code. PI = 4.0*atan(1.0); E = 120.0*PI;

L=1/4; A = L*PI; Io = 1; r=2;

k=2*pi;

THETA=0:0.01:2*pi; U =((cos(k/2*L.*cos(THETA))-cos(k/2*L))./sin(THETA)).^2*(E./(8.0*PI^2));

polar(THETA,U);

Answer 1

[Sandip Ghosal]

Hi,

The following code works fine.

PI = 4.0*atan(1.0); 
E = 120.0*PI;
L=1/4; 
A = L*PI; 
Io = 1; 
r=2;
k=2*pi;
THETA=0:0.01:2*pi; 
U =((cos(k/2*L.*cos(THETA))-cos(k/2*L))./sin(THETA)).^2*(E./(8.0*PI^2));
polar(THETA,U);

polar(THETA, RHO) makes a plot using polar coordinates of the angle THETA, in radians, versus the radius RHO. For more details of polar plot, please run:

help polar

Answer 2

[Michael]

Hmm.

PI isn't the same as pi. Use "pi". what is "E"? Is it "exp(1)"? if you fix this it gives a two-lobed polar plot

Answer 3

[Youssef Khmou]

hi, its working if you define PI and E :

 L=0.25;
 A=L*pi;
 lo=1;r=2;
 k=2*pi;
 E=1;
 THETA=0:0.01:2*pi;
 U =((cos(k/2*L.*cos(THETA))-cos(k/2*L))./sin(THETA)).^2*(E./(8.0*pi^2));
 polar(THETA,U); %  DIPOLE?