Low-Profile circularly polarized substrate integrated array antenna

In this paper, a novel low-profile circular polarization (CP) substrate integrated array antenna is proposed which is designed as a multilayer printed circuit board (PCB) structure, consisting of a lower feeding part-substrate integrated waveguide (SIW) and an upper radiating element - sixteen hollow square patches (HSP) evenly distributed in a square array and divided into four groups. The circular polarization (CP) characteristic is realized by chamfering each HSP in the left and right corners, and the greatest common bandwidth of the return loss and the axial ratio (AR) is obtained by adjusting the top chamfer size of each HSP. Simulation results show that the overall usable CP bandwidth is 41.2 GHz-42.1 GHz, the gain in the operating frequency band and the radiation efficiency (RE) are up to 16.1dBic and 91%, respectively, and the low-profile of antenna is less than 0.1 & lambda; (0).