Tapered slot antenna using photonic bandgap structure to reduce substrate effects

A simple and novel method is proposed to overcome the main beam splitting of a tapered slot antenna fabricated on a thick, high dielectric constant substrate. It employs a photonic bandgap structure comprising slots on the ground plane and conductor strips on the back of the substrate. Measured results at 35 GHz show a dramatic improvement in the radiation pattern and a measured front-to-back ratio of approximately 20 dB for both the H- and E-planes.