A Novel UWB And Miniaturized Antenna

With the rapid development of ultra-wideband wireless communication technology and software wireless radio (SWR), wide band, multi frequency and ultra wide band has become research hotspots in antenna field. A novel antenna , wideband monopole antenna with parasitic monopoles is proposed in the paper., and the antenna is studied and researched in detail.The wideband monopole antenna with parasitic monopoles is a kind of simple-structure and easy-feed wideband antenna. The wideband monopole antenna with parasitic monopoles has not only very wide impedance bandwidth, omnidirectional pattern in horizontal direction, stable gain, but also the ability of radiating and receiving time signal without distortion. The application prospect of wideband monopole antenna with parasitic monopoles will be fully broad, because it has simple structure and good electromagnetic characteristics. So it is suitable for mobile communication terminal device, especially, in handheld terminal and vehicle.Firstly, characteristic parameters of wideband antenna are introduced, and the definitions of characteristic parameters in time domain are presented. The bandwidth of wideband antenna is discussed. The structure and working principle of LPDA are briefly introduced for the next paragraphs.Secondly, the origin of the wideband monopole antenna with parasitic monopoles is presented; the reason of the antenna achieving wide band is qualitatively analyzed. The relation between the dimension parameters and impedance property is investigated by strict electromagnetic theoretical analysis. And so the design method of the monopole antenna with parasitic monopoles is presented. Through the electromagnetic simulation, the impedance property, radiation properties and ability of radiating and receiving time signal without distortion of the monopole antenna with parasitic monopoles are thoroughly analyzed, and then the influences of the dimension parameters on the impedance property and radiation property are studied. On the basis of former studies, the miniaturization structure of the wideband monopole antenna with parasitic monopoles is respectively analyzed and three feasible schemes are presented. At last, a handheld terminal antenna is made. By experiments, the return loss, radiation pattern and gain of the antenna are respectively measure to testify the theory and simulation studies.