A Broadband 360° Distributed Vector-Summing Phase Shifter Achieving <1.99°/0.22-dB RMS Gain and Phase Error over 8-to-110-GHz Bandwidth

This paper presents an ultra-broadband distributed vector-summing phase shifter with fine resolution over 8-100 GHz. The design consists of optimally weighted distributed variable gain amplifiers and a three-stage polyphase quadrature hybrid network. An optimal weighting distribution is introduced, where larger VGA cores are divided into smaller units to improve gain and phase matching without increasing area. This approach enhances robustness against PVT and further extends bandwidth. The impedance-invariant VGA maintains constant input/output impedances across all 1024 states up to beyond 100 GHz. Furthermore, the load-invariant property of the I/Q hybrid tolerates large load variations while maintaining phase and amplitude mismatches within 3° and 1 dB, respectively, across an entire decade of bandwidth. Fabricated in 22-nm FDSOI CMOS, it achieves phase shifting from 8 to 110 GHz, with a fine phase resolution of 3°, low RMS gain and phase errors of <0.22 dB and <1.99°, and power consumption of 13 mW.