A Wideband Low-Profile Phase Correcting Metasurface to Improve Directive Radiation Characteristics of Resonant Cavity Antennas

In this paper, we report the design of a planar phase-correcting metasurface (PCMS), constructed by true-time-delay (TTD) unit cells, that transform the nonuniform aperture phase of the conventional resonant cavity antenna (RCA) to a uniform one, producing highly directive radiation with improved aperture efficiency. We show full-wave simulation results demonstrating the successful generation of uniform phases even when the RCA cavity operates at the non-resonant frequencies. We show that the proposed RCA with the PCMS achieves a 3 dB gain bandwidth of around 35% with a peak gain of 20.2 dBi and an aperture efficiency of 23%. To the author's knowledge, the achieved bandwidth of 35% is the widest bandwidth reported for a class of RCA designed with planar PCMSs. We envision the proposed RCA to find applications in modern communication systems for long-distance communication or satellite connectivity.