A CPW-FED UWB MONOPOLE ANTENNA AND BIFURCATED ANTENNA WITH A VARIABLE NOTCHING FREQUENCY

A small and compact ultra-wideband (UWB) monopole antenna with variable frequency band-notched characteristic is presented. The antenna consists of a coplanar wave guide fed triangular shaped radiating patch with a parasitic resonant structure in the conductor backed-plane. It is shown that the when the antenna is bisected, the bifurcated antenna exhibits virtually identical characteristics as the original UWB antenna, including variable frequency band-notched characteristics. It is also shown that the antenna's VSWR characteristics can be enhanced by deforming the ground-plane with periodic open end-slits. The fabricated antenna has a small size of 21.5 x 21 mm(2), and the bifurcated antenna has a size of 10.75 X 21 mm(2). The bifurcated antenna is substantially reduced in size by 50%. Both antennas operate over the frequency band between 2.7 and 11 GHz for VSWR <2, whereas showing the band-rejection performance in the frequency band of 5.1-5.9 GHz. The proposed planar coplanar waveguide fed antennas are easily integrated with radio-frequency/microwave circuitry for low-manufacturing cost. (C) 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1545-1549, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25262