A Wideband Dumbbell-Shaped Magnetoelectric Dipole Antenna Array for Ka-Band Applications

This letter presents a novel wideband, high-efficiency dumbbell-shaped magneto-electric dipole (DS-MED) antenna array utilizing ridge gap waveguide (RGW) technology for Kaband applications. The array features three metal layers: a radiation layer with 8 × 8 DS-MED antenna elements, a hornshaped coupling cavity layer acting as a 1 × 4 power divider and enhancing bandwidth, and a contactless ridge gap waveguide feeding network. The proposed DS-MED antenna element exhibits wideband characteristics, and has a scalable geometrical structure suitable for large planar arrays, while the horn-shaped cavity collimates the electromagnetic waves more effectively to the DS-MED elements and optimizes impedance bandwidth with additional parameters. For validation, an 8 × 8 antenna array prototype is fabricated and tested. The measurement results demonstrate a -10dB wide impedance bandwidth of 30.3%, crosspolarization below -40 dB, and peak realized gain of 28.5 dBi. The proposed DS-MED array offers wideband operation, high efficiency, and scalability to large antenna arrays for Ka-band applications.