Multibeam 1-Bit Coding Programmable Metasurface Based on Superposition Method

Abstract

This letter proposed an algorithm utilizing the continuous phase superposition method to efficiently code multibeam 1-bit programable metasurface array. This method enables rapid metasurface array multibeam coding, which involves first calculating and superimposing the continuous phase matrix, and then the resulting code matrix is discretized. Additionally, an optimized algorithm is presented to lower the complexity of the overall procedure. The proposed algorithm enables the direct calculation of a maximum of 32 beam codes. The proposed algorithm exhibits high computational speed, low hardware resource consumption, and achieves high accuracy in generating beam pointing. The proposed algorithm addresses the issue of combining the number of beams, processing speed, and accuracy in the calculation of metasurface coding, which is not possible with standard algorithms. The algorithm is tested and validated using a 64 × 64 scale 1-bit metasurface array with meta-element full-wave simulation. During the test, 32 independent beams with arbitrary pointing directions are generated by the proposed algorithm. A maximum off-axis angle of 45° for the scanning range is supported by the proposed algorithm. Generated beams are both independent and clear, and the beam pointing error is limited to a maximum of 0.25%. The proposed algorithm for dual-beam coding achieves an average computation time of 1.18 ms, which is about 30 000 times faster than the typical nonlinear iterative optimization algorithm that takes 38 s.