A 24 to 30-GHz Phased Array Transceiver Front End With 2.8 to 3.1-dB RX NF and 22 to 24% TX Peak Efficiency

Abstract

This article presents a compact 24-30-GHz phased array transceiver (TRX) front end (FE) with high transmitter (TX) power efficiency and low receiver (RX) noise figure (NF) in a 130-nm bipolar CMOS (BiCMOS) technology supporting different 5th generation mobile network (5G) frequency range 2 (FR2) bands (n257, n258, and n261). We introduce an embedded antenna TX/RX (T/R) switch (SW) topology to co-optimize the performances of the power amplifier (PA) and the low-noise amplifier (LNA) while minimizing insertion loss and die area. The proposed TRX integrated circuits (ICs) also integrates a transmission line-based passive phase shifter and 1-bit phase inverter for phase control and a phase-invariant variable gain amplifier (VGA) for gain control, enabling orthogonal phase and gain control in the FE. On-wafer measurements of the TRX FE IC at 25 °C demonstrate TX mode peak power efficiency of 22%-24% and RX-mode NF of 2.8-3.1 dB, including the impact of the antenna T/R switch. The measured OP1dB and PSAT in the TX mode are 15.6-16.2 and 17.8-18.8 dBm, respectively. RF phase shifting measurements demonstrate < 5.6° phase resolution with gain variation lower than ±0.5 dB without the need for calibration. We implement phase-invariant gain tunability for orthogonal tapering and beam steering control; the measured phase variation is <± 1.5° for 8-dB gain tuning over 24-30 GHz. The IC was measured at a temperature up to 105 °C and maintains TX peak power efficiency > 19% with PSAT degradation < 1 dB and RX NF < 5.1 dB. The IC has an active area of 2.1 × 0.6 mm.