Low-Profile Highly Directive 2D-Beam-Steering Antenna in K_a-band with 3D-printed All-dielectric Sub-wavelength Deflectors

An elegant combination of a large-aperture planar radiating panel and a 2D-scanning part, implemented through a pair of 3D-printed sub-wavelength deflectors, is presented in this paper to demonstrate a low-profile 2D-scanning antenna system in K-alpha-band. A 28-cm-diameter prototype was manufactured, with in particular the dielectric deflectors fabricated by 3D printing of a high-permittivity and low-loss composite. The total height of the antenna system is only 4 cm, corresponding to 3.8 wavelengths at 29 GHz. The antenna system demonstrates a steering capacity up to 66 degrees in elevation and 360 degrees in azimuth, with a measured realized gain of 33 dBi at 0 degrees and 27.4 dBi at 66 degrees scan angle at 29 GHz. The 3dB-bandwidth is 6.5%, covering the 27.75-29.6 GHz range. The measured results validate the simulated steering performance of the system with good agreement and confirm the advantage of using this concept for achieving low-cost, low-profile, lightweight, and simple-configuration 2D-beam-scanning antenna.