A Wideband Energy-Efficient Multi-Mode CMOS Digital Transmitter

Beikmirza, M.R.; Shen, Y.; de Vreede, L.C.N.; Alavi, S.M.

doi:10.1109/JSSC.2022.3222028

A Wideband Energy-Efficient Multi-Mode CMOS Digital Transmitter

Title

A Wideband Energy-Efficient Multi-Mode CMOS Digital Transmitter

Author

Beikmirza, M.R. (TU Delft Electronics)
Shen, Y. (TU Delft Electronics)
de Vreede, L.C.N. (TU Delft Electronics)
Alavi, S.M. (TU Delft Electronics)

Date

2023

Abstract

This article presents a wideband, energy-efficient digital transmitter (DTX) suitable for multi-mode/multi-band wireless communication applications. It features various operation modes comprising Cartesian (Modes-1/-2) and multi-phase (Modes-3/-4) configurations utilizing LO clocks with different duty cycle in the interleaving/non-interleaving configurations. The multi-phase operation compromises polar and Cartesian features by mapping the I/Q signals into two non-orthogonal basis vectors with a 45° relative phase difference and a 3-bit phase selector scheme. The different operation modes are extensively analyzed and compared. Fabricated in a 40-nm CMOS process with an off-chip matching network, the proposed DTX occupies a core area of 0.72 mm2 and delivers 23.18-dBm RF peak power at 2.1 GHz from a 0.95-V supply voltage with drain/system efficiencies of 66.26%/52.59%, respectively. Utilizing a simple memory-less digital pre-distortion (DPD) for a 160-MHz four-channel 64-quadrature amplitude modulation (QAM) orthogonal frequency-division multiplexing (OFDM) signal, the DTX delivers an average P Out of 13.5/11.4/7.7/9.4 dBm, achieving an adjacent channel (power) ratio (ACL(P)R) of better than -42/-40/-40/-38 dBc and an average error vector magnitude (EVM) of -36/-34/-34/-32 dB, operating in Modes-1/-2/-3/-4, respectively. While transmitting a 200-MHz single-channel 256 (1024)-QAM OFDM signal at 2.4 GHz in Modes-1/-4, the average delivered output power is 14.11/9.29 (12.23/7.32) dBm with average drain and system efficiencies of 33.17%/26.3% (23.82%/22.83%) and 24.81%/22.85% (19.34%/18.81%), while the ACLR and EVM are better than -42/-41 (-43/-43) dBc and -34.6/-33.1 (-33.5/-33.9) dB, respectively.

Subject

Balun
Cartesian
CMOS
digital power amplifier (DPA)
digital pre-distortion (DPD)
digital transmitter (DTX)
efficient
load insensitive class-E
Marchand
multi-phase
radio frequency digital-to-analog converter (RF-DAC)
reactance compensation
re-entrant
wideband