High-Power Ridge Waveguide Four-Port Junction Circulator Based on Composite Post Resonators

An X-band high-power ridge waveguide (RW) four-port junction circulator is proposed in this article. It adopts two three-port RW junction circulators connected by a compact RW-to- coaxial-line transition in series with a parallel configuration topology. The composite post resonators are utilized in the three-port circulators. The theoretical analysis of composite post resonator and the design methods of the circulator have been demonstrated in detail. The RW transmission line, parallel configuration topology structure, and compact transition form make the cross-sectional size of the four-port circulator less than
$0.9\lambda \times 0.95\lambda $
at the central frequency of 10 GHz. Measurements show that the 12-dB isolation bandwidths of the circulator are 40% with an insertion loss of 0.2–0.7 dB. High-power tests show that its peak power capacity can reach about 7 kW.