Parametric Analysis of Reltron Modulation Cavity and Q-factor Calculation from S-parameter

Abstract

Resonant mode frequencies, S parameters and quality factors of reltron modulation cavity are obtained through computer simulation. CST Microwave Studio and MAGIC are used to find out the mode frequencies and the results are found to be in good agreement. A parametric study is performed to observe the change in mode frequencies with cavity dimensions and to identify proper cavity parameters for achieving good mode separation. S parameters are obtained in CST frequency domain solver by using probe coupled wave ports and the quality factors are calculated thereafter from S11. Impedance locus of S11 on the Smith chart shows critical coupling near resonance.