A PRINTED ANTENNA WITH CONSTANT GAIN OVER A WIDE BANDWIDTH FOR ULTRA-WIDEBAND APPLICATIONS

A constant-gain printed circular monopoly antenna (PCMA) is presented that operates from 4 to 12 GHz. The gain of the PCMA is enhanced with the use of surface-wave excited. proximity-coupled (SW-PC), conductor-backed. twin-slot radiators. A significant improvement in 2 and 3 dB peak gain bandwidth in the XY plane (Theta = 90) is achieved, and the peak measured gain of the antenna is nearly constant (5.5 dBi +/- 1.5 dB) front 3 to 10 GHz. It has a very broad radiation pattern in the azimuth plane and a typical figure of eight pattern in the elevation plane. The antenna is also compact, robust. and easy to fabricate. (C) 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1261-1264,2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25157