Geometrical Concepts for Phase-Shifting in Circularly-Polarized Reflector Antennas

This paper attempts to present a survey on techniques for beam scanning with circularly-polarized reflector antennas, concentrating on the ones that keep each reflector antenna element focused, including a new technique previously introduced by the author [1]–[3]. High gain reflector antennas are of main concern in this work (≽ 50 dBi), and possible scanning techniques are reviewed in light of geometrical concepts in conjunction with phased array methodology and notions of interferometry. It is not claimed that the work represents the state-of-the-art in phase-shifting control, but it does explore concepts and geometries involving intrinsic properties of circularly-polarized reflector antennas, explained in a straightforward manner, highlighting the educational aspect of the contribution. The concepts herein discussed are a work in progress and only preliminary results are discussed to illustrate the proposed configurations, without loss of generality.