Improvement of the radiation and impedence performance for the SIW H-plane horn antenna

In this paper, the impedance matching and radiation performance of the SIW H-plane horn antenna is improved by the modification of the probe and the adoption of a capacitive post in the feeding structure. The simulation results show that using the capacitive post and the modified probe, the reflection coefficient can be reduced, and the gain of the design can be improved in H-plane in the operation bandwidth from 27 GHz to 35.5 GHz as a result of the more uniform phase distribution at the radiation aperture.