Hi!

I am sending some reference to steer up your research.

1) Microstrip Antenna -design and analysis - D M POZER and D H SHAUBERT, page no 119. relation is b/a, b and a are the dimensions of the patch.

Thanks,

All The Best,

Thanks smrity for the answer.

But i am afraid you misunderstood the question.

I was interested in knowing if there is any mathematical relation between antenna feed and polarisation(axial ratio) to be specific.

The above reference just defines the axial ratio of an antenna.

Check this paper out "A novel simple and compact microstrip fed circularly polarized wide slot antenna with wide axial ratio for C-band application"

thanks Mubarak

Welcome. If you have any comments on it. you may share.

Typically a patch antenna is not circularly polarized. A secondary mode has to be excited in order for the polarization vector to be circular. Ways to do this include dual feeding, truncating the patch or adding stubs. The feed location determines the input impedance

Thanks Maree.

Due to narrow return loss bandwidth in my antenna,the frequency of 3db axial ratio and return loss are not at the same point.

I am having a hard time matching both of them.

Any suggestions??

One solution would be to operate the antenna (change your port impedance) at the impedance where you have good axial ratio

Dear Siddhant, Please refer K C Gupta's microstrip antenna book. Very useful.

Thanks maree sounds  a good idea to change the port mpedence