Sequential Hybrid Synthesis for Thinned Prephased Electronically Steered Phased Array Using Low-Resolution Phase Shifters and RF Switches

To reduce the complexity of large-scale electronically steered phased arrays (ESPAs) that use high-resolution attenuators and phase shifters, this letter proposes a sequential hybrid method. The method can synthesize a thinned prephased ESPA (TPESPA) that uses low-resolution phase shifters and 1-bit RF switches, while maintaining low sidelobe levels (SLLs) and high gains. The approach sequentially synthesizes the high-dimensional 0-1 amplitude vector, the prephase vector, and the one-dimensional reference phase. It thereby overcomes challenges such as slow computation, the unstable results of existing 0-1 amplitude algorithms, and the large storage demands of existing phasing methods. Simulations and measurements show that the synthesized$32\times 32$-unit TPESPA controlled by 2-bit phase shifters and 1-bit RF switches demonstrates SLLs between$-20.0$dB and$-18.0$dB, with an average increase in active gain of 1.1dB for a sparsity of 26.6% compared to a Taylor array using 6-bit phase-amplitude control.