Techniques to increase the beamwidth for patch antennas

Hi

I am looking for methods to increase the beamwidth for a patch antenna. I am currently looking into the stacked patch because I also need bandwidth and low cross-pol.

I need a beamwidth of 60 degrees or +/- 30 degrees of zenith where I have more or less constant gain. Currently the gain falls of approximately 2.5 dB at 30 degrees.

Hope it makes sense and somebody can help.

Thank you.

guess Beamwidth can be increased by reducing the patch width and also by having an appropriate reflector if size is not a criterion !

Hi

OK so reducing the patch width could help. In my case I need circular polarization and I use two feeds to acieve this. So wont this affect my radiation pattern when one side is change only.
Sorry but I am not that much into antennas.

Well size is definitely of matters, but some extra height could be tolerated.

Regards

yup .. u wil hv to sacrifice the bandwidth and ur pattern too cud get distorted ... if u got enuf height, y dont u try designin and simulating some kind of corner reflector ?

Dear tyassin,
see attached files.For increase bandwith you must use dual-offset feedline for slot feed patch.For increase bandwith you must use thick material for patch substrates like 0,81mm RO4003 for example.

other very interest atricle who I recomended is:
Design of Wide-Band Aperture-Stacked Patch Microstrip Antennas
S. D. Targonski, R. B. Waterhouse, Member, IEEE, and D. M. Pozar, Fellow,
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 46, NO. 9, SEPTEMBER 1998

Hi

Thank you for the info material.
Actually I have studied these papers, but as you state, it is for increased bandwidth. I am more interested in increased beamwidth or some measures to have some control over it.

I know the ground-plane is one parameter, but besides that I am not really sure.

Regards

There are other ways of obtaining circular polarization using only one feed if i'm not wrong.

Added after 5 minutes:

Am i right to say these for patch antennas :

1) Beamwidth is related to Directivity which is related to Gain and thus Area (Width). Assuming that wavelength is constant.

2) Bandwidth is inversely related to Q factor which is related to Volume.