Wideband circularly polarized magnetic‐electric dipole antenna using shorted stub for millimeter wave endfire radiation

A wideband circularly polarized (CP) planar endfire magnetic‐electric dipole antenna with single‐layer substrate integrated waveguide (SIW) is presented for millimeter‐wave (mm‐wave) communications. The antenna consists of an SIW feeding line, an electric dipole formed by two tilted shorted stubs and a magnetic dipole produced by an open‐ended SIW. Wideband CP radiation is implemented by simultaneously excited electric and magnetic dipoles in orthogonal phase, and its working principle is analyzed in detail by employing the traveling wave mode along the shorted stubs. The antenna prototype is fabricated and measured as a demonstration, which clearly demonstrates wide impedance bandwidth over 48.9%, wide axial ratio (AR) bandwidth of 46%, novel electric dipole structure, cost‐effective fabrication, and easy integration performance.