An Automatic Microwave Phase Comparator

A method for passively measuring the phase angle between two signals of the same frequency is described. While simple in concept, the system has no ambiguities throughout 360° and is independent of relative signal amplitudes because phase angle is displayed orthogonally to amplitude. Consisting principally of two hybrids with detectors and an X-Y indicator, the system contains no moving parts or active phasing devices. In addition to making routine phase measurements, it can be readily applied to automatic direction finders, polarization analyzers, and impedance plotters.