Arbitrary and Rigorous Aperture Illumination Synthesis in Huygens’ Metasurface-Based Leaky Wave Antennas

Abstract

Omega-type bianisotropic Huygens’ metasurfaces (HMSs) offer a novel approach for controlling the aperture field distribution of leaky wave antennas (LWAs). This article presents a methodology utilizing a parallel-plate waveguide with an MS as its top plate. Previous limitations on constant leakage factor are addressed using a slowly varying amplitude approximation (SVAA) in order to satisfy Maxwell’s wave equation, enabling the design of the radiation pattern. A semi-analytical algorithm is employed to obtain the required multilayer unit-cell geometries. Here, the interlayer coupling is taken into account, enabling an efficient synthesis of these antennas. Several designs presenting different pointing angles and aperture field distributions are carried out, showing very good agreement between theory and realistic simulations without further full-wave optimization. Finally, the design process is experimentally validated through several prototypes, whose measurements are shown and discussed. These results, demonstrating straightforward semi-analytical synthesis of versatile aperture profiles, would significantly broaden the applicability of such antennas in next-generation wireless systems.