A Review Study on Dual Band Notched Antenna for UWB Applications
A Review Study on Dual Band Notched Antenna for UWB Applications
Abstract: Ultra-wideband applications have grabbed much attention in the field of antenna because of it’s extremely wideband for high data rate applications. Since UWB antennas may transmit baseband signal without a carrier, the RF front end can be simplified and become inexpensive
Keywords: UWB, Dual Band Notched Antenna, Multi Band Antenna, Bandwidth Enhancement.
- INTRODUCTION
Ultra-wideband (UWB) signals are commonly defined as signals that have a large bandwidth (bandwidth divided by the carrier frequency) or a large absolute bandwidth. The use of large transmission bandwidth offers a number of benefits, including accurate ranging, robustness to propagation fading, superior obstacle penetration, resistance to jamming, interference rejection and coexistence with narrow bandwidth systems. On the other hand generating, receiving and processing UWB signals poses significant challenges that require new research in signal generation, transmission, propagation, processing and system engineering [1]. The first UWB signals were generated in experiments by Hertz in 1887, in which he generated sparks and radiated them via wide-band loaded dipoles. As time went on, emphasis of communication systems shifted to narrow band carrier-based (tuned) systems, which were easier to multiplex with the technology available at that time. It was only in 1990’s that the improvements in digital signal, processing, invention and investigation of time hopping (TH) impulse radio revived interest [2],[3]. This interest was greatly magnified by the decision of the U.S.frequency regulator, the Federal communications commission’s, to make the frequency band between 3.1 to 10.6 GHz available for unlicensed operation of UWB devices, subject to certain restrictions on the spectral emission mask. The initial applications of UWB technology were primarily radar related, driven by the promise of fine range resolution that comes with large bandwidth [4].
- ANTENNA DESIGN FOR UWB SYSTEM
Some of the desirable antenna characteristics for UWB radio systems are as follows: (i) Wide impedance bandwidth (ii) Fixed –phase centre over frequency (iii) High radiation efficiency.