book

Doherty Power Amplifiers

by Bumman Kim

March 2018

Beginner

184 pages

5h 38m

English

Academic Press

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Abstract1.1 Historical Survey1.2 Basic Operation Principle1.3 Offset Line Technique1.4 Other Load Modulation Methods
Abstract2.1 Correction for Lower Current of Peaking Amplifier2.2 Knee Voltage Effect on Doherty Amplifier Operation2.3 Offset Line Design for Compensation of Peaking Amplifier Phase Variation
Abstract3.1 Doherty Amplifier With Asymmetric Vds3.2 Optimized Design of GaN HEMT Doherty Power Amplifier With High Gain and High Efficiency3.3 Optimized Peaking Amplifier Design for Doherty Amplifier3.4 Saturated Doherty Amplifier3.5 Average Power Tracking Operation of Basestation Doherty Amplifier
Abstract4.1 N-Way Doherty Amplifier4.2 Three-Stage Doherty Amplifier
Abstract5.1 Introduction5.2 Design of Linear Doherty Power Amplifier5.3 Compact Design for Handset Application5.4 Implementation and Measurement5.5 Doherty Power Amplifier Based on CMOS Process5.6 Average Power Tracking Operation of the Handset Doherty Amplifier

Content preview from Doherty Power Amplifiers

Chapter Two

Realization of Proper Load Modulation Using a Real Transistor

Abstract

Various techniques for compensating the nonideal operation of the Doherty amplifier related to the transistor characteristics are discussed. For the proper load modulation of the Doherty amplifier, the transconductance of the peaking amplifier should be two times larger than that of the carrier amplifier. This problem can be solved by the uneven input power drive, 6 dB more input drive to the peaking amplifier. For the same purpose, the gate bias of the peaking amplifier can be adapted. The load modulation can be deviated from the ideal operation due to the knee voltage effect of a transistor and the large input capacitance variation of the class-C-biased peaking ...