64-Element 16–52-GHz Transmit and Receive Phased Arrays for Multiband 5G-NR FR2 Operation

This article presents 16–52-GHz multiband transmit and receive phased arrays designed to support multistandard 5G communications. The 64-element arrays are built using $16\,\times \, 1$ linear arrays, and each has four $4\,\times \, 1$ beamformer chips on a six-layer printed circuit board (PCB) with a Wilkinson combiner/divider network and tapered slot antennas. The wideband beamformer chips are designed in a SiGe BiCMOS process and use the RF beamforming architecture. The arrays have ±60° scanning capability in the azimuth plane and ±30° in the elevation plane with low sidelobes. The 64-element Tx array achieves an effective isotropic radiated power (EIRP) of 50–51.7 and 47.6–49 dBm at $P_{\mathrm{ sat}}$ and $P_{1\,{\mathrm{ dB}}}$ , respectively, at 24.5–48 GHz. The 5G-NR-compliant waveforms with 400 MHz and up to 256-quadrature amplitude modulation (QAM) are transmitted with <2.98% EVMrms and 34–36 dBm average EIRP. Single-carrier (SC) 400-MHz 64-QAM waveforms are also transmitted achieving <3% EVMrms with 39–40.3 dBm average EIRP and 2.4 Gb/s data rate. The 64-element Rx array achieves a system NF of 5.3–6.9 dB and a measured $G/T$ of −19.3 to −14.4 dB (with ${T} _{\mathrm{ ant}} = 295$ K) at 20–50 GHz, and < 2.6% error vector magnitude (EVM) performance when tested with 400-MHz 256-QAM 5G-NR-complaint packets. To the author’s knowledge, this work achieves the highest bandwidth Tx and Rx phased array systems suitable for multiband 5G operation.

I. Introduction

High data rate demands are driving the development of mm-wave communication systems. 5G networks are being deployed worldwide to support ultrareliable low-latency communications (uRLLC) serving applications such as autonomous vehicles, remote surgery, and virtual reality (VR). Therefore, regulatory bodies have auctioned multiple bands in the 5G new radio frequency range 2 (NR FR2) which spans 24.25–52.5 GHz. As a result, the development of mm-wave wideband communication systems is getting more attention to address the challenges of covering a widespread spectrum with a low-cost multiband/multistandard solution.