I. Awai et Ac. Kundu, Distributed coupling of dual-modes in a circular resonator and low-profiledielectric disk resonator BPF, IEICE TR EL, E82C(2), 1999, pp. 393-401
A novel method is proposed to calculate the distributed coupling of dual-mo
des in a circular resonator. New theoretical expressions are devised to acc
umulate the infinitesimal coupling between orthogonal modes and their valid
ity is justified by the FD-TD analysis and experiments. The distributed cou
pling concept of a circular disk resonator is applied to a square disk reso
nator to calculate its resonant frequency. We have fabricated two types of
low-profile dual-mode square dielectric disk resonator BPF, using high diel
ectric constant material (epsilon(r) = 93) having a dimension of 5 mm x 5 m
m x 1 mm. The filter characteristics are explained by the transmission line
circuit model.