Dielectric-Slab-Loaded Hollow Substrate-Integrated Waveguide $H$-Plane Horn Antenna Array at $Ka$-Band

A dielectric-slab-loaded hollow substrate-integrated waveguide (HSIW) H-plane horn antenna with improved impedance matching is proposed based on printed circuit board material FR-4. HSIW is utilized to avoid high dielectric loss. Apart from that, a dielectric slab is added by directly extending the substrates for gain improvement. Moreover, two coupling lines are added above and below the horn aperture for better impedance matching. The proposed HSIW H-plane horn antenna shows a maximum realized gain of 11.2 dBi with 77.6% radiation efficiency and 32.9% bandwidth (27.7-38.6 GHz). Based on the antenna element, a 1 × 4 HSIW H-plane horn antenna array is proposed. The array shows a maximum realized gain of 17.2 dBi with 66.5% radiation efficiency and 31.9% bandwidth (27.6-38.1 GHz). Good agreements of the measured and simulated results are achieved for both designs. The proposed antenna and array can be good candidates for low-cost millimeter-wave wireless communication systems.