Quasi-Optical Excitation of a Circularly-Polarized Metasurface Antenna at K-band

Abstract

This paper presents a new concept of modulated metasurface (MTS) antenna for satellite communications. As opposed to using cylindrical surface waves (SW) to excite circular apertures, we employ a quasi-optical beamformer to launch a plane SW. This architecture enables an efficient illumination of rectangular apertures. In addition, the use of anisotropic MTS elements allows us to obtain circularly-polarized beams with excellent characteristics in terms of cross-polarization discrimination. We present the design process of a prototype at K-band and the obtained simulation results, which prove the suitability of this antenna for satellite data links.

Reflecting Luneburg Lens: Analytical Solution and Applications

“…The latter behavior is the one sought for the RLL. Applying Snell's law at the circumference (n 0 sin α = n 1 sin ϕ out ) and using (7) and (5), one can write…”

“…Both PPWs are connected through a 180 o bend with parabolic profile, so a source in the focus of the parabola generates a plane-wave in the top PPW. This plane wave can be gradually radiated using a slotted array [5], [6] or a modulated metasurface [7]. Despite the elegance of this approach, the scanning performance of the parabolic reflector degrades (deterioration in side-lobe levels arising from coma phase errors) when the source is displaced from the focal point to steer the beam.…”