  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 drastic increase in
the data acquisition rate for hard-to-measure thin films that otherwise would
require long integration times.
