A research for millimeter wave patch antenna and array synthesis

Millimeter-wave antennas are one of the key parts in 5G systems due to its useful properties such as ultra wideband and high transmission rate. In this paper, the research of microstrip millimeter wave patch antenna at 28 GHz is proposed. The resonant frequency of microstrip antenna is shifted to the expanding bandwidth through slotting the patch. Meanwhile, adding punish function to fitness function is proposed to develop the bandwidth and improve the resonant frequency to desired frequency. The slot position is obtained by the genetic algorithm (GA). Furthermore, by using the numerical array synthesis, a linear uniformly spaced array model with feed network is obtained. The array with better radiation pattern is obtained through GA. The simulation results show that the bandwidth is improved from 0.9 to 1.25 GHz while the resonant frequency is remained at 28 GHz with the help of the proposed punish function. The side-lobe level is lowered by 4 dB and the maximum antenna gain is improved to 0.4 dB at the cost of 1° wider of half-power (HP) beamwidth.