Fully Analytical Design of Dual-Wire PCB Metagratings for Beam Steering and Splitting

Abstract

The printed circuit board (PCB) type metagrating (MG), a periodic microstrip planar structure with discrete distribution of polarization currents, can realize high-angle wavefront shaping with near-unity efficiency for potential application in high beam-steering antennas or reflectors. For large angle deflection, only a small number of meta-atoms are required in the metagrating’s period. As such, here we focus on a reflective PCB MG in the presence of only two meta-atoms, whose complex load impedance densities is explicitly derived from fully analytical expressions. The passive and lossless conditional equations as well as the equations for the power ratio control of the diffraction modes are given, which allows avoiding numerical optimization procedure. Three practical prototypes, including anomalous reflector and beam splitters are designed, simulated and measured. The measurement results agree well with the simulation results and are consistent with the theoretical predictions.