I am designing a receiver antenna for a wireless power transfer application.
The transmitter is a 2m x 2m horn antenna array that transmits a power signal at a frequency of 35 GHz from 100 meters away until it reaches my receiver. The radiation pattern of the transmitter is such that it focuses most of the energy on a 1m^2 area at the receiver such that I can assume a 1kW/1m^2 power density at my receiver. The transmitter is linearly polarized and the transmitter and receiver are straight looking at each other and are stationary.
I have to design the receiver antenna. For that, I have read a lot of literature books regarding antennas (Cheng, Pozar, Balanis etc.)
I don't know how to I determine what kind of a radiation pattern my receiver antenna must show in order to maximize the received power. From that how would I know how many antenna elements I will need at my receiver and what their inter-element distance should be?
Is it correct to assume that I simply need an antenna with maximum gain in the direction of the transmitter and everywhere else I don't need a high gain? How do I determine what beamwidth this must be, though?