Design of couplers for traveling wave RF structures using 3D electromagnetic codes in the frequency domain

In this paper, a simple equivalent circuit model of a traveling wave RF structure with input and output couplers is introduced. A few properties related to evaluating the reflection coefficient of the single coupler are then obtained and discussed. From these properties, a general procedure to design couplers for traveling wave structures using 3D electromagnetic codes in the frequency domain is derived. Finally, an example of coupler design for a 2 pi/3 X band accelerating structure is illustrated. (C) 2007 Elsevier B.V. All rights reserved.