A Broadband High-Gain H-plane SIW Horn Antenna

In this paper, a novel H-plane substrate integrated waveguide (SIW) horn antenna loaded with tapered periodic leaky-wave strips (TPLS) and a dielectric slab is proposed. The mismatching between the horn aperture and free space caused by the thinness of the substrate, leads to narrow impedance bandwidth and poor radiation performance for SIW horns. To enhance the bandwidth and gain performances, the TPLS are printed in front of the horn aperture, which guide and leak the electromagnetic waves gradually along the dielectric slab. Moreover, an extended dielectric slab placed in front of the TPLS further enhances the realized gain by more than 5 dBi. Simulated results illustrate that an impedance bandwidth of 60.8% is obtained from 20.6 GHz to 38.6 GHz with the return loss |S
₁₁
| below -10 dB. Meanwhile, a peak realized gain of 19.1 dBi is achieved at the frequency of 29 GHz, with the realized gain more than 9 dBi across the whole operating band. In addition, stable radiation patterns in both E-plane and H-plane are observed over the entire operating band.