Design of an X-band 4-channel circulator phase shifter based on silicon MEMS technology

To overcome the persistent challenges of excessive insertion loss and miniaturization limitations in conventional power-division phase-shifting networks for active phased-array radar front-ends, this work presents a silicon MEMS-based four-channel circulator phase-shifter integrating a ferrite circulator, directional coupler, four-way power divider, four 2-bit modified loaded-line phase shifters, and negative-voltage regulation circuits into a compact 24mm×15.5mm×2.7mm module weighing under 1.4g. Comprehensive characterization demonstrates excellent performance across the 9-10.2 GHz operational band, with <2.6 dB average insertion loss (excluding the inherent 6 dB power division), 95° maximum phase shift, 20±1 dB directional coupler coupling, better than -10 dB return loss, and robust 38.5 dBm input P1dB power handling. This highly integrated solution achieves unprecedented functional density while maintaining compact dimensions, lightweight construction, and low-loss characteristics, offering significant advantages for next-generation compact, high-performance, and cost-effective active phased-array radar systems.