Loaded Q-Factors of Partial-Height and Full-Height Triangular Resonators for Use in Waveguide Circulators

Except for some data on single and coupled, quarter-wave long, disk resonators operating in the waveguide turnstile mode, very little information is available on the loaded Q-factor of directly coupled resonators for use in the design of waveguide circulators. This paper investigates the dependence of the loaded Q-factor of resonators with triangular configuration on the orientation of its side dimension with respect to the output waveguide of the circulator. Coupling to the apex of the resonator corresponds to a lower value for the loaded Q-factor than is the case for coupling midway along its side. However, the difference is not as pronounced as in the case of stripline circuits. This work suggests that the apex coupled partial-height triangular rather than disk resonator may be the preferred geometry for use in the design of quarter-wave coupled waveguide circulators using single quarter-wave long resonators.