New Design for Transmitted Phase of Reflectionless Metasurfaces With 2 $\pi$ Coverage

Huygens' equivalent principle suggests that surface electric currents can be combined with magnetic currents to tailor electromagnetic (EM) wavefronts. Usually, the passive strategy is evolved into the concepts of sheet admittance and impedance. This paper attempts to resume the concepts of passive electric and magnetic currents and propose a novel design strategy for the transmitted phase of reflectionless meta surfaces with complete 2π phase coverage. Split meander lines, plus spiral rings, are carefully adjusted to accommodate complex equivalent currents for generating the required transmitted phase. Both experimental and theoretical results verify that meta cells proposed in this paper can be integrated to control the EM wave flexibly and efficiently. Furthermore, the concepts of combined passive electric and magnetic currents can be easily extended to design optical antennas and other plasmonic devices.