Design of Multi-beam Antenna Array Based on Phase Coding

An innovative multi-beam antenna is proposed, whose novelty is achieved by adjusting the phase relationship between antenna elements and performing encoding operations on them. Two types of broadband bidirectional radiating microstrip antennas are designed in this paper, with a phase difference of approximate 180 ° between them, corresponding to the "0" element and "1" element in digital coding. According to the principle of digital coding metasurface, a periodic coding arrangement of "01010101" is adopted to achieve dual-beam splitting in the +z and -z directions. This encoding method not only ensures the effectiveness of beam splitting, but also makes it possible to realize multiple beams. To verify the correctness of the theory, a 1 × 8 linear array is further designed. Full wave simulation results show that the antenna array obtains four beams pointing at approximate ± 50 ° and ± 130 ° at 13 GHz, with a relative bandwidth of 44.6 % and a maximum gain of 9.4 dBi. To achieve higher gain, a 3 × 8 planar array is constructed, with a relative bandwidth of over 30 % and a maximum gain of 13.4 dBi while maintaining the same number and direction of beams. The designed encoding antenna not only achieves broadband and high gain performance, but also exhibits good multi-beam characteristics.