Need help on choosing antenna parameters

Hi to all,
I am presently working on a research project in my university in India. I need to design a antenna for 2.4 GHz band. My aim is to make a rectenna (rectifier+ antenna).. I have read many IEEE papers on the same, but each paper seems to advocate different sorts of antennas as being the best. So my question is--
For 2.4 GHz, which is the best antenna in terms of gain and small size (and offcourse impedance matching) - 1) circularly polarized planar antenna
2) patch antenna
I would be grateful if anyone could provide some links related to antenna design at 2.4 GHz - something that considers size as crucial as I am designing for mobile/portable devices and applications...
Thanking you all in advance..
Pheonix.

The cicular polarized antenna just get the half of the power and if you need more power you should use linear pol. antenna. Circular polaried ones are for mobile applications. You can use the "Circular sector"antenna proposed by Itoh. It has 7 dBi in probe fed. It can be found in IEEExplorer website.

Regards

normally, we use linear polarization for antenna due to loss .

the antenna for mobile is often used PIFA or monopole ,

if you want to design the multiband antenna , you may combine

the PIFA and monopole .

another factor to use the PIFA is that it has stable efficiency and low SAR .