Enhanced Broadside Gain of an Ultrawideband Diamond Dipole Antenna Using a Hybrid Reflector

This communication studies the effect of a hybrid reflector on the radiation pattern of an ultrawideband diamond dipole antenna. The cause of a split radiation pattern in the broadside direction appearing when using a uniform artificial-magnetic-conductor-based reflector is investigated and is found to be due to destructive interference in the broadside direction produced by surface currents localized in certain areas of the reflector. A hybrid reflector is then proposed to mitigate this problem using both electrical and magnetic conductors. This solution enhances the gain in the broadside direction of the ultrawideband antenna. A complete antenna with a feeding system and a hybrid reflector has been fabricated and the measurement results are presented.