The Research Of Wideband Omnidirectional Dielectric Resonator Antenna

As one of crucial parts in the wireless communication system,the performance of the antenna directly affects the performance for the whole system.With the rapid developments of mobile communication systems,the transmission rate is more and more fast,which means the communication band turns more and more wide,which demands multi-band or broadband antenna.On the other hand,the existing communication band resource has been unable to meet the expansion of the communication system,so ultra wideband(UWB,3.1-10.6GHz)is also developed for the communication system.In modern communication system,the size and radiation efficiency of antennas play important roles and antenna miniaturization,broadband,high efficiency have become a research trend.The main research contents are as follows:1.Two vertical polarized omnidirectional antennas for indoor distribution system are designed.In first one,hybrid antenna technology has been used,a dielectric resonator around the monopole antenna is shaped by inverted cone and column,and the bandwidth of the antenna antenna can operate at 1.48?2.96GHz,peak gain over5dBi,efficiency over 94.5%.In second one,a stack of cone shaped DR which the inner layer of the antenna is a invertcone,as the outer one is a cone has been used around monopole antenna.Second one also using hybrid antenna technology can cover GSM800/GSM900/GSM 1800-1900/3G/LTE/Wifi2.4G/Bluetooth band,and the antenna size is beneath 0.34Ao x 0.34Ao x 0.23Ao(?o is wavelength of minimum operating frequency),and the peak gain is more than 4.5dbi,and the antenna efficiency is higher than 87%.2.A new UWB planar omnidirectional dielectric resonator antenna has been proposed.This antenna is fed by CPW,and a slot and the appropriate extension have been used on gnd.The radiators of antenna are printed monopole and DRA by using hybrid technique.To extend the bandwidth,a rectangular groove is digged for eliminating the higher harmonic at DRA center,and DRA is embedded in the substrate to make the feeding position flexiable.Antenna size is 0.15Aox0.28Aox 0.03 ?0,and relative bandwidth is 110%(center frequency at 6.59GHz),the radiation pattern is stable with omnidirectional characteristics over operating band,and antenna efficiency is up to 99%.In this thesis,two antennas for indoor distribution system and an antenna for UWB communication system have been proposed.Miniaturization,broadband and high efficiency have been considered into antennas design,and radiation patterns of antennas are stable with omnidirectional characteristics over operating band.