Good morning, I'm planning to build a planar phased array, the purpose of which is to perform near-field focusing (beamforming) in the non-radiating near-field (Fresnel zone), therefore in an area in front of the array. I decided to use a carrier frequency of 800 MHz, and use cavity patch antennas, and divide the antennas into two groups, the first group having a carrier frequency of 800 MHz and amplitude modulated (pulses) at 200 Hz, and the second group also having a carrier frequency of 800 MHz, and amplitude modulated at 300 Hz, to create a difference beat in the target area. My problem concerns the size of the patches, I'm undecided between half-wave or quarter-wave, the half-wave patches have greater gain and less beam distortion, but are large, while the quarter-wave patches have greater asymmetry, less gain but are smaller, so for my project which of the two options is best???

