HF-guiding structures: Technology and applications

This article addresses a fundamental point of view that alone justifies the development of the digital techniques already discussed in the article [E 1 170] and the fundamental theory of guiding structures in general, discussed in the article [E 1 171] . Indeed, it should be remembered that the overall objective of these two articles is to lead to the effective implementation of microwave and millimeter wave devices. This leaves an important aspect concerning the practical and technological aspects of these structures. It has been emphasized that the shape of the guides depends on several factors such as the operating frequency, the power carried, and the application and/or implementation on substrates dedicated to integration with other components for greater compactness. This is why, in a first step, the material aspects of the technology (materials and physico-chemical manufacturing techniques) are presented. In a second step, we focus on circuit design support techniques. Indeed, a waveguide or any other component can be represented by a distribution matrix linking the transmitted and reflected powers to the different accesses. When these are connected to other modules, it is possible to represent the overall distribution matrix that takes internal connections into account. Next, performance in terms of attenuation due mainly to losses in dielectrics and conduction is discussed, with other types of losses being briefly discussed. In addition, we look at power limitations due to heating and breakdown phenomena, briefly describing their mechanisms and giving some numerical examples. Finally, the areas of application and prospects for microwave and millimeter wave circuits are presented.

At the end of the article, readers will find a glossary and a table of ratings and symbols used.