A 140 GHz Scalable On-Grid 8×8-Element Transmit-Receive Phased-Array with Up/Down Converters and 64QAM/24 Gbps Data Rates

Abstract

This paper presents a scalable wafer-scale transmit-receive phased array at 140 GHz. The chip is composed of 2-D 8x8 140 GHz channels employing radio-frequency (RF) beamforming with 4-bit phase and gain controls at 135–145 GHz. An up/down-converter (UDC) channel with a x6 LO chain and an IF of 9–14 GHz is also integrated on the chip. The on-chip RF distribution network is composed of Wilkinson divider/combiner networks, along with line amplifiers (LAs) to provide signal amplification. The chip is fabricated in GlobalFoundries CMOS 45RFSOI technology with an area of 9.84*8.27 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and is flipped on a low-cost organic RF PCB containing 8x8 patch antenna array placed at 1.07xl.22 mm grid (0.5A x 0.57A at 140 GHz). The array can scan ±60° for both transmit and receive operations. The measured TX EIRP is 37.5 dBm at 140 GHz. The measured RX array input 1-dB compression point is -11 dBm with an electronic gain of 20 dB at 140 GHz. The array supports 16/64 QAM operation with up to 24 Gb/s with <4% EVM <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rms</inf> for both transmit and receive operations. This work presents the first phased-array at 140 GHz with wide-angle scanning and full scalability in the X and Y directions.