Planar lens using mixed-order spatial elliptic filter

This paper presents a novel design approach to simplify thin planar lens structure maintaining overall capability of phase shift. It is introduced that constructively utilizing inter-layer coupling between metal layers renders Elliptic filter response and this can control electrical dimensions of the lens for thin configuration while inter-layer couplings between metal layers has been commonly ignored or considered as a factor to cause an error between simulation and measurement results. Furthermore, it is presented that combining different-order of this-type spatial filter response can significantly reduce the required number of metal and substrate layers providing the same level of tunable range of phase shift of the prior lens requiring larger number of metal and substrate layers.