A Multi-Beam Antenna Based on Modulated Metasurface

In this paper, modulated metasurface based multibeam antenna is presented. The impedance superposition method of all impedance modulations for different beams is utilized in the design. The current reported multi-beam modulated metasurface has a very small number of beams due to the mutual interference of different impedance modulations. It is found that the source locations for each beam play a key role in interference suppression. Instead of using the time consuming full-wave simulation-based optimization, in this paper, the optimal source locations are obtained by using the aperture fields calculated from the zeroth-order approximation of the currents on the metasurface. A five-beam modulated metasurface antenna has been designed, providing an angular coverage up to +/- 30 degrees. The peak realized gain for the broadside beam is 21.3 dBi at 14.30 GHz.