A 28-GHz Low-Power Phased-Array Receiver Front-End With 360° RTPS Phase Shift Range

• Published in: IEEE transactions on microwave theory and techniques Vol. 65; no. 11; pp. 4703 - 4714
• Main Authors: Garg, Robin, Natarajan, Arun S.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.11.2017; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: 5G cellular communications; <italic xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">Ka -band; Beamforming; CMOS; complete 360° phase shifter; Couplers; Design optimization; Extremely high frequencies; Gain; gate–drain capacitance can-cellation; Impedance; Insertion loss; low insertion loss and rms phase error; low power; low-noise amplifier (LNA); millimeter-wave reflection-type phase shifter (RTPS); neutralization LNA; Noise levels; passive phase shifter; Phase error; Phase shift; Phase shifters; Phased arrays; phased-array receiver (RX); Power consumption; scalable arrays; State of the art; switched transmission-line phase shifter; Varactors; π-load
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2017.2707414

A low-power 28-GHz phased-array receiver (RX) front end is presented that incorporates a low-power low-noise amplifier (LNA) and a passive reflection-type phase shifter (RTPS) capable of 360° phase shift with 5-b phase resolution and low gain variation. Passive phase shifters are limited by tradeoffs between phase resolution, insertion loss, and phase shift range. The proposed RTPS load design and optimization approach leads to a 28-GHz RTPS achieving the state-of-the-art insertion loss with 360° phase shift range and low loss variation across the phase shift. The LNA adopts a transformer-coupled neutralization architecture that increases available gain, enabling lower power consumption. The phased-array front end is designed for Ka-band applications and has been implemented in 65-nm CMOS. The measured RTPS achieves 360° phase shift with 7.75 ± 0.3 dB insertion loss and an rms phase error of 0.3° at 28 GHz. The low-power phased-array RX front end has an overall gain of 9.5 ± 0.4 dB and noise figure <;5.5 dB at 28 GHz. The RX front end consumes 10 mW from a 0.9-V supply with phase shifter and an LNA active area of 0.16 and 0.32 mm 2 , respectively, in 65-nm CMOS, demonstrating its suitability for low-power phased-array RX for emerging wireless links.