Circularly Polarized Slot Antenna Array Based on Metal-Integrated Suspended Line at mm- Wave Band

This paper presents a circularly polarized slot antenna array applied in millimeter waves based on Metal-Integrated Suspended Line (MISL). The array is composed of four basic antenna units, and each unit has a pair of transverse and longitudinal slots. The feeding part of the antenna is a bent suspended line, which reduces the array area via its bending structure and generates circularly polarized waves through slot coupling. The use of MISL structure eliminates the dielectric loss in traditional antennas. The proposed antenna has a simple and compact structure with a low profile. The simulation results show that the -10 dB impedance bandwidth of the antenna is 27.77-31.99 GHz, the 3 dB axial ratio bandwidth is 28.51-30.98 GHz, and the axial ratio of the antenna is only 0.067 dB at 30 GHz, indicating excellent circular polarization performance.