Millimeter-Wave Continuous-Mode Power Amplifier for 5G MIMO Applications

Abstract

This paper presents three millimeter-wave (mm-wave) continuous-mode power amplifiers (PAs) for fifth-generation (5G) MIMO applications, including a two-stage differential continuous-mode Class-F−1 PA in 130-nm SiGe process, a single-stage differential continuous-mode hybrid Class-F/F−1 PA in 45-nm SOI CMOS process, and a two-stage differential continuous-mode hybrid Class-F/F−1 PA in 45-nm SOI CMOS process. The first PA design covers 19–29.5 GHz, while the other two designs cover 23–41 GHz, all covering multiple 5G bands (24/28/37/39 GHz). All the presented PA designs are based on a proposed transformer-based continuous-mode harmonically tuned PA output network. This network provides proper harmonic impedance terminations for the fundamental, second-order, and third-order harmonic impedances, which supports continuous-mode Class-F−1 or hybrid Class-F/F−1 PA operations to achieve ultrawide bandwidth yet high efficiency. The first PA design achieves a wide $P_{\mathrm {sat}}~1$ -dB bandwidth of 19–29.5 GHz (43.3%) and high peak power-added efficiency (PAE) (43.5%). The second design achieves an ultrawide $P_{\mathrm {sat}}~1$ -dB bandwidth of 23.5–41 GHz (53.3%) and high peak PAE (46%). Moreover, it achieves 43.4% PAE and 18.6-dBm $P_{\mathrm {sat}}$ at 27 GHz, 40.2% PAE and 18.6-dBm $P_{\mathrm {sat}}$ at 37 GHz, and 41.2% PAE and 18.5-dBm $P_{\mathrm {sat}}$ at 39 GHz, respectively. The third PA design also achieves an ultrawide $P_{\mathrm {sat}}~1$ -dB bandwidth of 23.5–41 GHz (53.3%) and high peak PAE (43.2%). It achieves 43% PAE and 18.9-dBm $P_{\mathrm {sat}}$ at 27 GHz, 37% PAE and 19-dBm $P_{\mathrm {sat}}$ at 37 GHz, and 36% PAE and 18.9-dBm $P_{\mathrm {sat}}$ at 39 GHz, respectively. Extensive 64-/256-QAM modulation tests demonstrate the high PA linearity. Our proposed PA designs outperform the reported mm-wave silicon-based 5G PAs in terms of high efficiency over an ultrawide bandwidth.