A Microwave Interferometer of the Michelson-Type to Improve the Dynamic Range of Broadband Ferromagnetic Resonance Measurements

We present a Michelson-type microwave interferometer for use in ferromagnetic resonance experiments. The interferometer is capable of broadband operation without manual adjustment of phase delay or amplitude attenuation. A prototype of the design shows significant improvement of the signal-to-noise ratio when compared to non-interferometric ferromagnetic resonance experiments. We demonstrate that this increase in sensitivity can lead to a dramatic increase in the data acquisition rate for hard-to-measure thin films that otherwise would require long integration times.