Chen Y.-TChiu M.-LTeng H.-WTSUNG-HSIEN LIN2021-09-022021-09-022021https://www.scopus.com/inward/record.uri?eid=2-s2.0-85106557624&doi=10.1109%2fVLSI-DAT52063.2021.9427340&partnerID=40&md5=268f9af66d0f1d1692553678676eb13dhttps://scholars.lib.ntu.edu.tw/handle/123456789/581171A 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.current-recycling OTA; envelope-tracking power amplifier; Hybrid supply modulator; IQ-controlled class-AB output; power-added efficiency; zero-peaked comparator[SDGs]SDG7Delay 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 amplifiersconference paper10.1109/VLSI-DAT52063.2021.94273402-s2.0-85106557624