Research on Beamforming Antenna with Cosecant Squared Pattern by Independently Adjusting the Amplitude and Phase of Each Unit on SIW

In this paper, a 12-element substrate integrated waveguide beamforming antenna for mm-wave band is proposed. The antenna structure consists of transverse slots, matching vias, and phase shifters. By optimizing the geometry of the slots and phase shifters, the excitation amplitude and phase of each unit can be controlled flexibly. The slot length and the width of the phase shifter are designed based on the excitation coefficient obtained by the genetic algorithm, and the cosecant squared pattern is realized successfully. The simulated results show that the impedance bandwidth ($\left\vert S_{11}\right\vert <-10 ~\text{dB}$) of the antenna array is between 22.7 24 GHz and the peak gain is 13.6 dBi. The designed radiation pattern is consistent with expected cosecant squared pattern very well, and an angular beamforming range of 44° can be achieved at 24 GHz, which prove the effectiveness of the beamforming antenna design in this paper.