3D directional antenna pattern

Hi All, I have been struggling for 2 day with problem I mentioned in title. I would like to visualize the 3D antenna pattern with 70 degrees beamwidth (half power angle) for horizontal plane and 15 degrees for vertical plane. I would like to see directivity (shape) and gain (as color of shape). I got some result but it is not what I wanted to see. I'm using standard approach with meshgrind and sph2cart functions, maybe I make mistake somewhere. I attached the code and image presenting the beam. Link to beam plot: http://speedy.sh/PwYen/an.png

clear all
close all

AntennaGain = 14; % typical gain for below angles
hangle3db = 70;
vangle3db = 15;

[phi theta] = meshgrid(-180:180,-90:90);
Zin =  - (12*(phi/hangle3db).^2 + 12*(theta/vangle3db).^2);
Zin = Zin + AntennaGain; % total gain 

mnz = min(min(Zin));
mxz = max(max(Zin));

shape = Zin;

[x y z] = sph2cart(phi*pi/180,theta*pi/180,shape);
surf(x,y,z,'EdgeColor','none')
daspect([1 1 1])

I would be so grateful for any comments and remarks.

Regards Maciek

Answer 1

[Honglei Chen]

I couldn't really comment on the pattern itself but I think part of the issue is that your color is not appropriately applied. You can try to replace your surf with the following command

   surf(x,y,z,'EdgeColor','none','CData',Zin)

[Maciej]

Thanks for your comment, but unfortunetaly it dosen't solve my problem at all. BTW I would like add something, namely how can I take into account the distance, is it possible, I'm afraid not, but maybe I'm wrong ?

Cheers

Maciek

[Honglei Chen]

Could you explain then what the issue is? What is the result you want to see?