Optimization by Excitation Shaping of a Transmitting Subarray Radiation Parameters With a Constrained Receiver Leakage

This paper describes a method of finding a constrained optimum excitation of a generic transmitting antenna subarray. Constraint of a maximum power coupled from the transmitting to the receiving subarray is discussed. Optimum realized gain, optimum gain, and optimum directivity goals are covered. The proposed method can operate on any generic multi-port antenna, with no assumptions taken on the geometry, the constituent elements construction, or the interelement coupling. This paper in particular investigates dense linear arrays and analyses the applicability of several typical transmitter/receiver partitionings to the proposed method. Achieving a below -30 dB TX-to-RX total coupling with less than 1 dB realized gain penalty over a 135° scanning angle is demonstrated for below-half-wavelength spaced 73 GHz E-band PCB-based linear arrays.