Single Layer Dual Circularly Polarized Antenna Elements for Automotive Radar at 77 GHz

In this paper, two different configurations of dual circularly polarized antenna elements in single layer gap waveguide (GW) are presented for 77GHz automotive radar systems. Both of the antenna configurations utilize slot element to radiate and generate circular polarizations. The right-hand circular polarization (RHCP) and the left-hand circular polarization (LHCP) are generated at the same working frequency with different input ports. The simulated results show that both two antenna elements could cover the proposed impedance bandwidth (75-80 GHz) with an axial ratio lower than 2 dB.