Single-layer phase transforming surfaces for performance enhancement of resonant cavity antennas

<p dir="ltr">Resonant cavity antennas (RCAs) have a great potential to substitute reflectors and arrays due to their simple feedings, directive radiation patterns, and planar structures. However, conventional RCAs suffer severely from non-uniform near-field phase distribution, adversely impacting their far-field performance. There have been some attempts to rectify RCAs’ phase distribution errors, primarily relying on multi-layered dielectric prototyping. Such methods contribute to higher fabrication costs, greater loss, and heavier superstructures. This thesis proposes a new generation of phase transforming surface (PTS) for RCAs that uses only a single dielectric laminate, unlike the previous counterparts. The PTS is composed of unit cells arranged in semi-circular patterns inspired by the actual phase distribution of the RCA to compensate for the aperture phase error. Two single-layer PTS were designed to improve the near-field uniformity of the RCA based on the presented methodology. As a result, the peak directivity of the antenna systems is significantly increased by 5.5 and 8.5 dB, reaching 18 and 18.5 dBi, respectively. These improvements introduce RCAs as a real candidate for fixed beam communications and pave the way for modern applications such as communication on the move.</p>