A Novel Cost-Efficient Linear and Rectangular Planar Phased Array Design With Low-Sidelobe Levels Using Two-Way Array Factor

The design of a radar phased array two-way radiation pattern, which is the product of transmit and receive array factors, typically suffers from undesired minor lobes near the main beam, along with the hardware cost and complexities associated with transmit/receive (T/R) modules and beamforming network design. This paper presents a systematic approach for reducing the peak sidelobe level (PSLL) in two-way radiation patterns of phased arrays with both linear and rectangular planar geometries. Specifically, for a given linear or planar transmit array with all elements active, we propose a receive array configuration that employs only a limited number of active elements. This approach reduces cost, complexity, and power consumption while maintaining a low PSLL in the two-way radiation pattern. The proposed receiving array is based on a Quasi-Uniform Sparse Receive Array (Q-USRA) configuration, whose aperture can be either smaller or larger than that of the transmit array. This configuration aligns the receive nulls (SLL peaks) with the SLL peaks (nulls) of the transmit array pattern, thereby achieving a low PSLL in both linear and planar two-way radiation patterns. The design parameters of the Q-USRA configuration (i.e., the number of active elements and the receive aperture length relative to the transmit array) are obtained via an exhaustive search and are independent of transmit array size for both linear and rectangular planar array geometries. This approach enables flexible array design while overcoming the computational challenges associated with methods based on genetic algorithms (GAs), combinatorial traversal algorithms (CTAs), and mixed-integer programming (MIPs). The theoretical findings are further validated through full-wave simulations with microstrip patches and dipoles as radiating elements, thereby confirming the suitability of the proposed array design framework for realistic implementations.