Periodically non-uniform coupled microstrip lines on longitudinally-magnetised ferrite

Non-uniform coupled lines, which corrugate periodically not only on the inner edges but also on the inner and outer edges of the conductors, are proposed on longitudinally-magnetised ferrite for the first time. Compared with the conventional parallel ferrite-coupled-line (FCL) section, the corrugated structure can modify the operating frequency for non-reciprocity without changing the physical length of the conventional one. In addition, the simulated performance of a periodically non-uniform FCL section indicates a significant performance improvement of broader bandwidth.