High-gain planar lens antennas based on transformation optics and substrate-integrated waveguide (SIW) technology

Abstract

Transformation of space coordinates is a tool to synthesize material properties in view of obtaining a controlled electromagnetic field pattern. Also, substrate-integrated waveguide (SIW) technology can well be exploited to develop microwave and millimeter-wave components. In this paper, by combining these features, high-gain SIW planar lens antennas are proposed. Using the embedded transformation-optics lenses, both narrow beamwidth of 12◦ and low sidelobe levels of −23 dB are achieved for the H-plane radiation patterns by a single antenna. The designed transformation-optics lenses can be realized by drilling spatially varying cylindrical holes in an ordinary dielectric substrate. The E-plane radiation patterns can also be improved through the dielectric slabs in front of the antenna aperture integrated in the same substrate. Therefore, using SIW technology, the lens antennas can be fabricated on a single substrate. An H-plane sectoral horn and a Maxwell-fisheye-based lens antenna are designed using the proposed method. Simulation results confirm the validity of the proposed idea and the advantages of these lens antennas.