Low-profile microwave lens antenna based on isotropic Huygens' metasurfaces

An isotropic electromagnetic (EM) lens based on Huygens' metasurface is proposed for 28.0 GHz lens antenna design. The lens consists of a series of non-resonant and subwavelength metallic patterns etched on both sides of an ultrathin dielectric substrate. Both electric and magnetic responses are introduced to realize desired abrupt phase change and high-efficiency transmission for the secondary wavelets in the incident wavefront. Then, a substrate-integrated waveguide (SIW) fed patch antenna is combined with the lens as the primary feed to form a low-profile lens antenna system. The simulated and measured results coincide with each other, and demonstrate that the prototype realizes 8.8 dB∼12.6 dB gain increment and low side-lobe levels over the bandwidth of 26.7 GHz∼30.0 GHz. The novel design leads to a low-profile, light weight, and low-cost antenna solution in a wireless communication system.