Leaf-shaped bowtie antenna backed by a periodic patch-loaded grounded slab

As a planar-type wideband antenna being useful for UWB radio systems, the authors have previously proposed a leaf-shaped bowtie antenna. In this paper, we present a design of a leaf-shaped bowtie antenna in which a periodic patch-loaded grounded slab is used in order to realize a unidirectional beam over a wide frequency range while maintaining a low-profile configuration. In order to demonstrate effective performance of the presented configuration, fundamental characteristics of the antenna are investigated and revealed by the finite-difference time domain (FDTD) analysis and measurements.