Millimeter-wave End-Fire Circular-Polarized ME Dipole Antenna

This paper presents a three-dimension (3D) wideband 45 GHz circular-polarized ME (Magneto-Electric) dipole antenna with end-fire radiation property. It consists of a circular-polarized ME dipole radiator and a feeding SIW (Substrate Integrated Wave-guide). In addition, these two components are mutually vertical in space and the open end of the feeding SIW is employed to work as a coupling window for electromagnetic energy. Besides, two parallel metal baffles are loaded onto this coupling window to adjust the impedance matching between the ME dipole radiator and the feeding SIW. Therefore, the simulated impedance band-width of the proposed antenna for |S11|<-10dB can reach up to 22.2% from 40GHz to 50GHz. Furthermore, a stable LHCP gain which variation range is 8.5 +/- 0.25 dBic over the operating band and a 3 dB AR (Axial Ratio) bandwidth of 16.7% are achieved.