Complex gyrator circuit of a waveguide junction circulator using an Okada resonator

Abstract

Conventional waveguide junction circulators usually consist of either a single or a pair of coupled quarter-wave long gyromagnetic resonators in a turnstile arrangement, or a planar post one in contact with the top and bottom walls of the junction of three H-plane waveguides. Another geometry that has much to commend it is that obtained by suppressing the axial resonance in the geometry, using either the single or the pair of coupled quarter-wave long resonators. The complex gyrator circuit of a junction circulator using such a weakly magnetised resonator is approximately developed in terms of effective constitutive parameters and is experimentally verified. The construction of a quarter-wave coupled device is separately described. Circulators using such resonators have been tested at 6000 W-CW at S-band, 1500 W-CW at X-band and 400 W-CW at J-band.