140 GHz Wide Scan Lens Antenna Design

Abstract

We introduce the design of an array-fed dielectric lens antenna that enables electronic beam steering within a large Field of View (FoV). The feed array consists of eight cavity-backed double-slot antenna elements, fed by a microstrip feed structure that tilts the beam of each double slot toward the lens center. The slots are loaded with a two Artificial Dielectric Layers (ADL) to increase the front-to-back ratio. The elements are placed closer to the lens surface with respect to the nominal focal plane and are combined with proper weights to reduce the scan loss. Metallic reflectors are positioned along the sides of the array edges to further improve the scanning performance, especially at large scan angles. Full-wave simulations show that the designed antenna realizes a stable gain around 20 dBi within a ±50° FoV coverage, for a lens diameter of 5 wavelengths.