TABLE OF CONTENTS Microwave amplifiers are designed using mathematical techniques that require the use of network parameters. These network parameters describe how a circuit responds to certain input stimuli. Most amplifiers are designed by determining the circuit's function and then creating a circuit to accomplish something very close to what is required. For example, the circuit might be an amplifier with a specified gain and input and output impedance. This circuit is designed by forming an electronic network of various components. Using calculations, we can predict the circuit's gain and impedance match. To make these predictions, we must have a uniform method of describing circuits or networks of components and the circuit descriptions must be characterized mathematically. Circuit parameters are defined to represent the actions and responses of a circuit in mathematical terms. When we postulate a stimulus, e.g., when a television signal is being sent down a coaxial cable, we can calculate the likely circuit response to that signal.
This chapter introduces three types of circuit parameters describing electronic networks. These parameters, called the Z-, Y-, and chain parameters, are common in designing circuits up to two gigahertz but are not often used in microwave circuit design. We begin with these parameters because they are easy to understand and used in most computer-aided design (CAD) programs.
A circuit, or network, is defined by identifying pairs of terminals that will be used as an input or output. Often one of the terminals in a pair is a ground and may not...
