Design of reconfigurable UHB Antenna with miniaturization for Wireless Applications

Abstract

Recently, the demand of multi-functionality for mobile devices with different newlinestandards of wireless communication is increased. In this scenario reconfigurable newlineantennas have received a great deal of attention because future wireless communication newlinesystems such as cognitive radio required reconfigurable antennas to perform its newlineabilities either for spectrum sensing or communication. Reconfigurable antennas are newlinecapable of reconfiguration of certain antenna parameters such as operating newlinefrequency, radiation pattern and polarization in order to satisfy the requirement of newlinemultiple functions. Many frequency band reconfigurable antennas have been newlinedesigned that combine the narrowband and wideband functionality by using newlineswitching elements. newlineSecond chapter of this thesis is focuses on realization of a compact novel newlinefrequency-band reconfigurable antenna with five switching modes; UWB mode, two newlinenarrowband and two dual-band modes. The proposed structure is intended for use in newlinecognitive radio and multi-radio wireless applications. Prototype uses switchable newlineslotted ground plane with five p-i-n diodes that provides the band-reconfigurable newlinecapability. The effect of parametric analysis and optimization by using simulator is newlinepresented. The antenna is simulated by using CST Microwave Studio (CST MWS) newlinesoftware, consequent to which it is fabricated and experimentally validated. Beside newlinethis by implementing the circular loop FSS (frequency selective surface) with newlineproposed antenna provide the average gain improved about 4-5 dB. The E-plane newline(XZ plane) patterns are quasi omnidirectional in nature whereas the H-plane newlineradiation patterns resemble dumbbell shape. newline