Design and Analysis of Directional Ultra Wideband Antennas with Multiband Applications

Abstract

Recently, all-embracing efforts have been made by researchers to design an antenna that newlinecan fulfill the current needs of wireless communication systems such as multiband, directional newlineand omnidirectional characteristics integrated into a single antenna. This approach is focused newlineon reducing the size of the antenna, low power consumption, wide operating band-width and newlinesupport for modern applications in the field of wireless communication such as WCDMA, Wi- newlineMax, Bluetooth and WLAN. Ultra-wideband (UWB) antenna plays a significant role in newlinecontemporary communication systems. An appropriate UWB antenna should have the ability newlineto operate over an ultra-wide bandwidth as per the allocation proposed by the Federal newlineCommunications Commission (FCC). UWB system features make antenna design challenging newlinein terms of radiation pattern, directional characteristics, wide-ranging impedance bandwidth, newlinedirectivity and gain and also it should be compact. In portable devices, proper isolation of the newlineantenna is a challenging issue. This thesis focuses on the design and modeling analysis of an newlineUWB antenna with directional characteristics and further integration of multiband is done to newlinemake the antenna suitable for modern wireless communication systems. Investigations are newlinebeing conducted on three compact antenna structures. These designs comprise circular newlinedirectional UWB antenna with a folded strip resonator, quad dumbbell shaped directive UWB newlineantenna with meander strip resonators and a directional UWB antenna having a semi-circular newlinepatch with capacitive folded strip resonators and also floral-shaped slots inserted in the patch. newlineDetailed investigations are conducted into the development processes of designed antennas to newlineensure thorough understanding of their application as a multiband antenna with the integration newlineof lower wireless band applications along with directional and ultra-wideband characteristics. newlineThe antennas being proposed are created based on the Defected Ground structure (DGS) newlineconcept, which can support multiple resonances.