Nonreciprocal microwave devices based on magnetic nanowires

Abstract

We use magnetic nanowires in an alumina matrix as the active element in microwave nonreciprocal resonance isolators. The design is related to waveguide E-plane isolators but is planar and much smaller than typical waveguide isolators. There is a nonreciprocal attenuation of the wave in forward and reverse directions. The isolation is about 6 dB/cm at 23 GHz. The bandwidth of the device is relatively large (5–7 GHz) in comparison to ferrite-based devices. The central frequency of the device can be tuned with the application of magnetic field.