Noble Publishing is pleased to continue its series of design guides with the release of Power Amplifier Design. Amplification is fundamental in all electronic systems. In the past, the mathematics of amplifier design was simpler. Bandwidth and power efficiency were the primary challenges. Classic AM and FM systems were distortion tolerant. This is not so for modern data and communication systems where amplifier distortion limits performance. This collection from previous issues of Applied Microwave & Wireless includes articles of timeless interest and articles that cover the latest techniques.

The first five articles discuss the specification, analysis and measurement of distortion from different perspectives. The article by Staudinger studies the relationships between intermodulation distortion (IMD) and adjacent channel power ratio (ACPR or ACP). The article by McCune and Bayruns proposes the use of the effective output intercept point as a transmitter figure of merit. Amoroso and Monzingo suggest the use of the parasignal to analyze spectral regrowth. In their first article in the guide, Heutmaker, Welch and Wu propose using BPSK as a practical method of characterizing amplifier distortion and in their second article they reveal that distortion hysteresis requires memory in distortion models to improve accuracy. The next three articles by Amoroso and Monzingo and by Stapelton discuss the use of various predistortion techniques to reduce spectral regrowth.

The article by William Brown, The Magnetron A Low-Noise, Long-Life Amplifier, is a fascinating example of a technology transfer in reverse. Technologies developed for space, defense and other high-end applications often migrate to...