A broadband planar patch antenna fed by a short probe feed

This paper presents a novel design of a broadband probe-fed planar patch antenna. The proposed antenna has a thick air-layer substrate, and bandwidth enhancement is achieved by cutting a small portion of the ground plane and adding an inverted U-shaped ground plane to be close to the radiating patch, and then feeding the antenna at the inverted U-shaped ground-plane portion using a 50-/spl Omega/ coax feed with a short probe pin. Prototypes have been successfully implemented, and experimental results show that an impedance bandwidth (1:1.5 VSWR) greater than 20% can be achieved for the proposed antenna. Radiation characteristics of a prototype suitable for application in a DCS cellular system (1710-1880 MHz) base station are also presented.