Superstrate-Based Beam Scanning of a Fabry-Perot Cavity Antenna

Incorporating phased array technique to scan the main beam of a Fabry-Perot cavity (FPC) antenna produces sidelobes proportional to the scan angle. An alternative dielectric-ferrite superstrate-based scan mechanism with controlled sidelobe level is presented in this letter. A beam scan of 24 ° is demonstrated by axially magnetizing the ferrite part of the superstrate with ΔH = 0.25 T. Stepped dielectric part of the superstrate is optimized to reduce the sidelobe level of the FPC antenna by 4.49 dB. The fabricated antenna is tested to verify the simulated radiation patterns and reflection responses. The requirement of magnetic biasing can be considerably reduced using LTCC technology, where biasing coils are embedded within the ferrite superstrate.