Novel Topology of Reversed Wave Attenuation in Microstrip Ferrite Edge-Guided Mode Isolator

This letter reports a novel ferrite isolator topology based on the edge-guided mode principle with an asymmetrical stub perturbation that achieves nonreciprocal behavior without absorbers, shorted strips, or vias. Implemented on a single metallized ferrite substrate, the design offers a clean, low-cost, and highly reproducible solution compatible with planar fabrication processes. Unlike prior edge-guided mode implementations, the proposed topology enables reverse-wave suppression using only geometrical perturbations, significantly simplifying fabrication and improving integrability. A prototype operating at 2.4 GHz was designed using combined electromagnetic (EM)–magnetostatic (MS) simulations and then fabricated for experimental validation. Measurements confirm a worst case insertion loss of 1.5 dB and a 6.6% fractional bandwidth where both reflection and isolation exceed 20 dB. The compact, via-free structure and its compatibility with planar antennas make this isolator a suitable building block for front-end modules in wireless communication systems, particularly where size and manufacturability constraints dominate.