Axisymmetric Resonant Lens Antenna With Improved Directivity in Ka-Band

A compact-size shaped dielectric lens antenna (DLA) is designed and optimized in Kα-band (29.5 GHz) using a new synthesis tool based on the combination of a genetic algorithm and BoR-FDTD solver. The antenna is fabricated in Rexolite and fed by a circular waveguide with a flange and an optimized integrated dielectric taper. As demonstrated, the proposed antenna combines features intrinsic to lens, resonant, and reflector antennas. The attractive performance of the antenna (in terms of directivity and sidelobe level) is demonstrated numerically and experimentally by comparison to a conventional extended hemispherical DLA.