Some Design Considerations for High-Frequency Transistor Amplifiers

A survey of the mass of available literature on high-frequency transistor amplifier design discloses the constantly present problem of amplifier sensitivity and even instability, especially when so-called maximum available gain amplifier designs are attempted. This problem is the result of the internal positive feedback inherent in all known transistors. This paper is particularly directed toward a better understanding of transistor internal feedback and its relationship to transistor amplifier design and performance. A fresh and practical engineering approach to the problem of transistor amplifier sensitivity and stability evaluation is presented. The presentation is largely concerned with basic design principles.* Specific amplifier design discussion is limited to that needed * The material in the paper covers the basic design principles presented in a talk on "The Design of RF and Video Amplifiers" given by the author as one of a series of six lectures on Transistors -- Their Circuits and Applications, sponsored by the Dallas, Texas, Section of the Institute of Radio Engineers. 1551