Distributed coupling in a circular dielectric disk resonator and its application to a square dielectric disk resonator to fabricate a low-profile dual-mode BPF

A novel method is proposed to calculate the distributed coupling of a circular disk resonator. New theoretical expressions are devised to calculate it and its validity is justified by FD-TD analysis and experiments. This coupling concept is applied to square disk resonator to calculate its resonant frequency. We have fabricated two types of low-profile dual-mode bandpass filter using square dielectric disk resonator.