2000 W mean-power X-band waveguide junction circulator using a composite turnstile resonator

A description is presented of a forced-air cooled 2000 W mean power WR90 waveguide circulator at 8.4 GHz using a directly coupled composite turnstile resonator. Waveguide circulators using composite turnstile resonators are discussed. It is pointed out that microwave ferrite and garnet materials have relatively low values of thermal conductivities compared to some dielectric ones such as alumina, beryllia, and quartz. It is, therefore, difficult to design heat sinks in the case of ferrite resonators employed in the construction of high-mean-power junction circulators. One approach for improving the thermal capacity of ferrite resonators involves the replacement of a part of the ferrite or garnet material with a dielectric substance. An example of such a resonator is the composite turnstile resonator considered by Helszajn (1981).