Design and Implementation of a Dual Frequency and Bidirectional Phase Gradient Metasurface for Beam Convergence

A phase gradient metasurface (PGM) array with beam converge characteristic in reflection direction at 15 GHz and transmission direction at 5.6 GHz is proposed in this letter. Compared with the traditional unidirectional PGM, the proposed PGM can achieve bidirectional radiation at two frequencies. A horn is used as the feed placing at a focal length of 200 mm of PGM array. Simulation results show that the horn has a peak gain enhancement of 11.9 dB at 15 GHz with a -3 dB beamwidth reduction of 33 degrees in reflection direction and a peak gain enhancement of 7.9 dB at 5.6 GHz with a -3 dB beamwidth reduction of 30 degrees in transmission direction. The proposed PGM array achieves a beam convergence in two directions at two different frequencies and has a potential use for communication system consisting of receivers with multifrequency and multilocation characteristic.