Millimeter-Wave Wideband Circularly Polarized Magnetic-Electric Dipole Antenna for Endfire Radiation

A circularly polarized (CP) magnetic-electric-dipole (ME-dipole) antenna with wideband endfire radiation is presented for millimeter wave communications. The antenna comprises substrate integrated waveguide (SIW) with an open end in the middle substrate, two top and bottom substrates with via-shorted triangle patches, and an offset parallel line. The via-shorted triangle patch exciting by the offset parallel line is regarded as an electric dipole and the open ended SIW line serves as an efficient magnetic dipole. Two dipoles are simultaneously excited by an SIW feeding line for wideband CP endfire radiation. Lastly, we measured and verified the scheme by an antenna prototype. The proposed CP endfire antenna also has gain scalability and potential multibeam applications.