A Wideband Millimeter-Wave Endfire Antenna Fed by Substrate Integrated Coaxial Line

This paper presents a wideband endfire antenna fed by substrate integrated coaxial line (SICL) for millimeter-wave applications. Endfire radiation is obtained by combining an arc metallic tapered slot radiator and a compact open-ended parallel plate waveguide. Through a blind via and a metallic radiating wedge, broadband excitation is provided for the radiating part. The presented antenna owns an impedance bandwidth of more than 85% (20–50 GHz) and a maximum gain of 7.9 dBi at 35 GHz. For the sake of wideband performance and easy integration, the endfire antenna presented here is a candidate with great promise for mmW wireless applications.