Coupled-Resonator Slow-Wave Structures for Travelling-Wave Tubes
TWT amplifiers remain the microwave power amplifiers of choice for high power microwave and mm-wave systems for land and aerospace applications. This book aims at advancing the present technology of TWTs with coupled resonator SWSs by enhanced analytical (quasi-TEM and equivalent circuit analysis) and the field analysis codes, improved modelling, simulations and experimentations.
Using these techniques, new variants of coupled resonator SWSs like ladder-core inverted slot mode SWS and the inductively loaded interdigital SWS have been investigated. The possibility of achieving both coalesced mode design that gives wide bandwidth and multi beam design that improves the peak power and gain is presented.
An improved modelling and simulation technique using 3D electromagnetic codes has been proposed. A field analysis model for corrugated wave-guidee SWS, based on Coupled Integral Equation Technique (CIET), which is a combination of Mode Matching Technique (MMT) and Method of Moments is presented. The analysis will be very useful, especially to microwave engineers aiming to improve the TWT design for higher levels in power, efficiency and bandwidth.
Electromagnetic Modeling of Waveguide Discontinuities
The accurate analysis of waveguide discontinuities is an important problem in microwave communications. The objective of this three part work is to analyze the scattering properties of various types of waveguide discontinuities.
In the first part, the general theory of rectangular waveguide, and the various numerical methods for computing scattering parameters of both the E-plane and H-plane waveguide discontinuities asr discussed. The second part of the work presents the method of obtaining the scattering parameters of H-plane discontinuities and cascaded H-plane discontinuities using Mode Matching Technique (MMT) and Equivalent Circuit approach.
In the third part of the work, MMT is extended to a new field analysis code based on a combination of MMT and Method of Moments called the Coupled Integral Equation Technique (CIET). CIET is applied to analyse circular corrugated waveguide discontinuities. It was found that CIET plays a major role in improving the performance by its efficient handling of singularities and in achieving accuracy.