Power coupling

TL;DR

This paper provides an overview of power coupler design principles, addressing various RF structures, design criteria, and challenges such as field distortion and multipacting, with illustrative techniques using electromagnetic codes.

Contribution

It offers a comprehensive summary of power coupler design concepts, including techniques for normal-conducting and superconducting structures, and discusses common problems and solutions.

Findings

Comparison of normal-conducting and superconducting couplers

Analysis of field distortion and multipacting issues

Electromagnetic code-based design techniques

Abstract

Power coupling is the subject of a huge amount of literature and material since for each particular RF structure it is necessary to design a coupler that satisfies some requirements, and several approaches are in principle possible. The choice of one coupler with respect to another depends on the particular RF design expertise. Nevertheless some 'design criteria' can be adopted and the scope of this paper is to give an overview of the basic concepts in power coupler design and techniques. We illustrate both the cases of normal-conducting and superconducting structures as well as the cases of standing-wave and travelling-wave structures. Problems related to field distortion induced by couplers, pulsed heating, and multipacting are also addressed. Finally a couple of design techniques using electromagnetic codes are illustrated. The paper brings together pictures, data, and information from several works reported in the references and I would like to thank all the authors of the papers.