Focal Plane Array Receiver for Deep-Space Communication

Typical ground antennas intended for use in space communication require large apertures operating at high frequencies. The challenges involved with these applications include achieving the required antenna performance in terms of antenna aperture efficiency and pointing accuracy. The utilization of a focal plane array in place of a standard single mode feed minimizes these problems. This paper discusses the key elements required to implement a focal plane array on a large high frequency antenna. It is shown that adaptive "least mean-square" (LMS) algorithms applied to the output of the array elements obtain the optimum combining weights in realtime, even in the presence of dynamic interference such as nearby spacecraft in array\´s field-of-view, or planetary radiation. This adaptive optimization capability maximizes the combined output SNR in real time, ensuring maximum data throughput in the communications link when operating in the presence of receiver noise and external interference generally present during planetary encounters.