A Novel Reversed T-Match Antenna With Compact Size and Low Profile for Ultrawideband Applications

A new unidirectional antenna composed of a reversed T-match dipole, a microstrip feeding line and a ground plane is presented for low-profile ultra-wideband (UWB) applications. This antenna is an improvement over the folded dipole antenna, as it achieves a compact size and a low profile through the introduction of shorting branches on the opposite layer. Detailed descriptions of the structure and design are presented. The antenna occupies an area of 23 mm × 32 mm, and the height above the ground plane is 18 mm (about a quarter of a wavelength at mid-band). Simulated and measured results are studied and compared, which show that the proposed antenna has stable directional radiation patterns, a wide bandwidth from 2.89 GHz to 6.50 GHz, and a gain of 6.0 dBi to 9.4 dBi.