Risley Scanner Using a Metasurface Source and a Single Deflector for SATCOM Applications

This paper presents a 2D-beam-steering antenna for Satcom applications based on a simplified Risley scanner, which consists of a leaky-wave feed and a single deflector fabricated by additive manufacturing. Such a configuration simplifies classical Risley scanners, where a source illuminates a combination of two prisms. The pointing direction of the radiated beam is controlled by the relative azimuthal positions between the leaky-wave feed and the deflector. The leaky-wave feed comprises a modulated metasurface antenna fed by a quasi-optical system to maximize its aperture efficiency. The angular dispersion of the metasurface is engineered to reduce the beam squint in the frequency band of interest while preserving the efficiency and compactness of the structure. In turn, the deflector is composed of partially dielectric-loaded metallic waveguides, achieved through the combination of two additively manufactured parts. A prototype validates the concept showing a field of view of 360° in azimuth and 50° in elevation with a maximum realized gain of 25.4 dBi at broadside at 20.2 GHz.