Embodiments include methods and apparatus for detecting a phase angle between an incident signal and a reflected signal. The apparatus comprises a plurality of phase shifters and additional circuitry. The plurality of phase shifters is adapted to apply first phase shifts to a representation of the incident signal and to apply second phase shifts to a representation of the reflected signal. The additional circuitry, which is operatively coupled to the plurality of phase shifters, is adapted to produce a first indication of a location of a relative phase difference between the incident signal and the reflected signal within a first region of a first reference circle, and to produce a second indication of the location of the relative phase difference within a second region of a second reference circle, wherein the second reference circle is rotated with respect to the first reference circle.