Hunter Ian. Theory and Design of Microwave Filters

The Institution of Engineering and Technology, 2001. — 353 p.Microwave filters are vital components in a huge variety of electronic systems, including cellular radio, satellite communications and radar. The specifications on these devices are usually severe, often approaching the limit of what is theoretically achievable in terms of frequency selectivity and phase linearity. Consequently an enormous amount of published material on this topic is available and anyone new to the subject is in danger of being overwhelmed with information. The design of filters is unusual in that it uses network synthesis, with which it is possible to apply systematic procedures to work forward from a specification to a final theoretical design. This is the converse of most engineering disciplines which tend to use design rules based on analysis. A pre-requisite to skills in network synthesis is a thorough grounding in the circuit theory of passive networks, a subject often treated superficially in modern electrical engineering degree courses. However, a knowledge of network synthesis is not the only tool needed in order to design filters. Synthesis provides the designer with a prototype network which can then be transformed into a variety of microwave networks including TEM transmission lines, waveguides and dielectric resonator realisations. Thus the designer also has to have a reasonable knowledge of the properties of the electromagnetics of these devices. This book evolved from a series of lectures on filter design which the author gave to engineers at Filtronic pIc and MSc students at Leeds and Bradford Universities. The purpose of the book is to provide a single source for filter design which includes basic circuit theory, network synthesis and the design of a variety of microwave filter structures. The philosophy throughout the book is to present design theories, followed by specific examples with numerical simulations of the designs. Where possible pictures of real devices have been used to illustrate the theory. It is expected that the book will be useful to final year undergraduate, MSc and PhD students. It should also form a useful reference for research workers and engineers who are designing and/or specifying filters for commercial systems.