Conformal SIW H-Plane Horn Antenna on a Conducting Cylinder

This letter presents a conformal wide-band substrate integrated waveguide (SIW) H-plane horn antenna mounted on a large conducting cylinder. The effect of a curved low-profile SIW H-plane horn is examined when it is mounted on a conducting cylinder of varying radius. In order to compensate the deterioration of the voltage standing wave ratio (VSWR) of the H-plane horn antenna, two air slots along the sides of the flare part of the antenna are cut. With the utilization of the slots, the matching between the feed line and the horn antenna is improved and the working frequency bandwidth is broadened simultaneously. Measured VSWR of the fabricated antenna is below 2.5 from 6.1 GHz to 19 GHz. The antenna also exhibits stable radiation beam over the same frequency range. It is observed that measured results agree well with simulated ones.