Integrated Broadband Edge-Guided Mode Isolator With Antiparallel Biasing of the Ferrite Slabs

In this letter, a novel configuration of the integrated waveguide edge-guide (EG) isolator, containing two antiparallelly biased ferrite slabs separated by a dielectric gap (DG), is reported. It is found that in this configuration the transmission losses are significantly lower than the ones observed in an EG mode isolator completely filled with ferrite (without a DG). The principle of operation of the proposed isolator is analyzed numerically and the obtained low losses originate from the wave transmitted in the gap. This behavior is also demonstrated using the prototype of this type of isolator working at 6.25 GHz, where simulated and measured results show isolation of 48 dB and insertion losses of 1.3 dB.