Rapid Prototyping of Ultrawideband Compact Resonant Cavity Antennas Using 3D Printing

The Far-field radiation performance of classical RCAs is compromised because of even transmission through uniform superstrate resulting in non-uniform aperture phase distribution. Permittivity gradient superstrate (PGS) can be used to improve uniformity in aperture phase distribution and hence better directive radiation characteristics. The paper presents a technique to rapidly prototype lowcost PGS for the ultrawideband high-gain RCAs using 3D printing. The PGS has nine dielectric sections with distinct permittivity, which can be realized by the 3D printing infill method. The predicted build time of PGS using low-cost Acrylonitrile butadiene styrene (ABS) filament is 2:02 hours. The synthesis is performed in a single step, without using traditional multistep milling and machining of dielectrics. With an equivalent material cost of US$ 1.63, the PGS has cost and prototyping superiority over the recently presented counterparts. Simulation results of 3D printed PGS based RCA indicate peak directivity of 15.5 dB, 3-dB directivity bandwidth of 50.7% and sidelobe levels less than -12.5 dB throughout the operating frequency band, which is comparable to all recently reported expensive RCAs.