Measuring Amplifiers
Joel P. Dunsmore · 2020
Amplifiers are often considered in the system design as a unilateral gain block use to boost signals, and for the inexperienced system designer, that is often as far as the amplifier characteristics are considered. They can be roughly split into two categories: low-noise amplifiers used in receiver applications, and power amplifiers used in transmitter applications. This chapter explores most of the attributes of amplifier measurements important to an radio frequency or microwave designer or test engineer, with the exception of noise figure. The most basic attributes of an amplifier are often considered as purely linear; thus, the fundamental description of most amplifiers is the S-parameter matrix of the amplifier. However, amplifiers differ from passive linear circuits in that the power scattered from an amplifier will always be greater than the power incident on the amplifier.