An accurate tuning method for dual-mode cavity filters

摘要

An accurate tuning method using a short-ended dummy cavity is presented for dual-mode cavity filters. Tuning is based on the match of the computed and measured phase responses of the reflection coefficient. An equivalent circuit model is adopted for computing the required phase response of the reflection coefficient. This method is applied to a 4-pole longitudinal dual-mode filter for demonstration. Good agreement is found between the experimental and computed responses.