A 71–76GHz Four-Element Phased-Array Receiver with Compact Footprint in 65-nm CMOS

This paper presents a 71–76 GHz four-element receiver in 65-nm CMOS for highly integrated phased-array applications. A novel magnetic-coupling-based Wilkinson combiner is proposed to reduce the size and improve power combining efficiency. The receiver also features an active phase shifter with a phase-adjustable I/Q signal generator to improve phase resolution under various process, voltage, and temperature (PVT) conditions. Each receiver channel occupies a 0.76 mm² area with a 57-mW power consumption, achieving a 360° phase-shifting range with a 6-bit resolution and a 12-dB attenuation range with a 1-dB step. The measured rms phase and gain errors at 0-dB attenuation are 0.95–1.05° and 0.14–0.23 dB, respectively. The receiver offers a compact and low-power solution for phased-array applications.