A Hybrid Supply Modulator for 10-MHz LTE Power Amplifier with 17.3% PAE Improvement
Journal
2021 International Symposium on VLSI Design, Automation and Test, VLSI-DAT 2021 - Proceedings
Date Issued
2021
Author(s)
Abstract
A hybrid supply modulator (HSM) is proposed for the envelope-tracking power amplifier (ET-PA) to improve its power- added efficiency (PAE). The proposed HSM consists of a linear amplifier (LA) and a switching amplifier (SA). The LA adopts a current-recycling OTA (CROTA) followed by an IQ-controlled class- AB output stage. The CROTA enhances gain and slew rate of the LA first stage. In the class-AB output stage, the quiescent current (IQ) is regulated to reduce its sensitivity to process and supply variations. The SA employs a zero-peaked hysteresis comparator for switching control, which reduces the time delay of the SA control loop, and leads to better power efficiency. Measurement results shows that the HSM reaches 75.2% efficiency at 29.3-dBm output power. When tested with a commercial PA, the PAE improves by 17.3% at 22-dBm RF output power with 34.9-dB power gain. ? 2021 IEEE.
Subjects
current-recycling OTA; envelope-tracking power amplifier; Hybrid supply modulator; IQ-controlled class-AB output; power-added efficiency; zero-peaked comparator
Other Subjects
Delay control systems; Efficiency; Operational amplifiers; Sensitivity analysis; VLSI circuits; Envelope tracking power amplifiers; Hysteresis comparator; Linear amplifiers; Power efficiency; Power-added efficiency; Quiescent currents; Switching amplifiers; Switching Control; Power amplifiers
Type
conference paper