Chapter 7. Class A Amplifiers

  1. W. Alan Davis PhD1 and
  2. Krishna K. Agarwal PhD2

Published Online: 9 OCT 2001

DOI: 10.1002/0471200689.ch7

Radio Frequency Circuit Design

Radio Frequency Circuit Design

How to Cite

Davis, W. A. and Agarwal, K. K. (2001) Class A Amplifiers, in Radio Frequency Circuit Design, John Wiley & Sons, Inc., New York, USA. doi: 10.1002/0471200689.ch7

Author Information

  1. 1

    University of Texas at Arlington

  2. 2

    Raytheon Systems Company

Publication History

  1. Published Online: 9 OCT 2001

Book Series:

  1. Wiley Series in Microwave and Optical Engineering

Book Series Editors:

  1. Kai Chang

Series Editor Information

  1. Texas A&M University

ISBN Information

Print ISBN: 9780471350521

Online ISBN: 9780471200680



  • class A amplifiers;
  • gain;
  • transducer power gain;
  • two-port circuit;
  • S parameter;
  • simultaneous match;
  • maximum power gain;
  • stability;
  • power combining;
  • problems


The class A amplifier is typically used as the first amplification stage of a receiver or transmitter where minimum distortion is desired. This comes with a cost of relatively low efficiency. Since the first stages in an amplifier chain handle low-power levels, the low efficiency of these amplifiers actually wastes little power. The variety of amplifier classes are described in cited references and are covered more extensively in a later chapter. The primary properties of importance to class A amplifier design are gain, bandwidth control, stability, and noise figure. These are the topics that will be considered here.