Saved in:
Bibliographic Details
Main Authors: Bai, Zhidong, Yuan, Wen, Azam, Ali, Walling, Jeffrey S.
Format: Preprint
Published: 2020
Subjects:
Online Access:https://arxiv.org/abs/2002.04152
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914316092964864
author Bai, Zhidong
Yuan, Wen
Azam, Ali
Walling, Jeffrey S.
author_facet Bai, Zhidong
Yuan, Wen
Azam, Ali
Walling, Jeffrey S.
contents This paper presents a 4-channel beamforming TX implemented in 65nm CMOS. Each beamforming TX is comprised of a C-2C split-array multiphase switched-capacitor power amplifier (SAMP-SCPA). This is the first use of multiphase interpolation (MPI) for beam-steering. This technique is ideal for low-frequency beamforming and MIMO, as it does not require passive or LO based phase shifters. The SCPA is ideal to use as the core element since it can perform frequency translation, data conversion and drive an output at high power and efficiency in a compact die area. A prototype 4-element beamforming TX, occupying 2 mm X 2.5 mm, can achieve peak output power of 24.4 dBm with a peak system efficiency (SE) of 24%, while achieving < 1° phase resolution and <1 dB gain error. When transmitting a 15 MHz, 64 QAM long-term evolution (LTE) signal it outputs 18.4 dBm at 14% SE with a measured adjacent channel leakage ratio (ACLR) < -30 dBc and error vector magnitude (EVM) of 3.27 %-rms at 1.75 GHz. A synthesized beam pattern based on measured results from a single die achieves <0.32°-rms beam angle error and <0.15 dB rms beam amplitude error.
format Preprint
id arxiv_https___arxiv_org_abs_2002_04152
institution arXiv
publishDate 2020
record_format arxiv
spellingShingle Multiphase interpolating digital power amplifiers for TX beamforming
Bai, Zhidong
Yuan, Wen
Azam, Ali
Walling, Jeffrey S.
Signal Processing
This paper presents a 4-channel beamforming TX implemented in 65nm CMOS. Each beamforming TX is comprised of a C-2C split-array multiphase switched-capacitor power amplifier (SAMP-SCPA). This is the first use of multiphase interpolation (MPI) for beam-steering. This technique is ideal for low-frequency beamforming and MIMO, as it does not require passive or LO based phase shifters. The SCPA is ideal to use as the core element since it can perform frequency translation, data conversion and drive an output at high power and efficiency in a compact die area. A prototype 4-element beamforming TX, occupying 2 mm X 2.5 mm, can achieve peak output power of 24.4 dBm with a peak system efficiency (SE) of 24%, while achieving < 1° phase resolution and <1 dB gain error. When transmitting a 15 MHz, 64 QAM long-term evolution (LTE) signal it outputs 18.4 dBm at 14% SE with a measured adjacent channel leakage ratio (ACLR) < -30 dBc and error vector magnitude (EVM) of 3.27 %-rms at 1.75 GHz. A synthesized beam pattern based on measured results from a single die achieves <0.32°-rms beam angle error and <0.15 dB rms beam amplitude error.
title Multiphase interpolating digital power amplifiers for TX beamforming
topic Signal Processing
url https://arxiv.org/abs/2002.04152