Miniaturization And Broadband Wire Antenna Research

The miniature and wide band of equipment become more important than before as the development of communication technology. On the other hand, the UWB (Ultra-wide band) communication system which have the characteristics with large communication capacity, small average power density and good anti-interference capability and need miniature and wide band components, is a development direction in 21st century. At this background, the miniature and wide band technology of antenna become more and more important.This dissertation mainly researches the ultra-wide band communication antennas and electrically small antennas. Many technologies of electrically small antennas and wide band antennas are discussed in theory, simulation and experiment. And some novel electrically small or wide band antennas are proposed. The loaded monopole is analyzed in depth integrating the genetic algorithm (GA) with the method of moments (MoM) in order to increase the gain and decrease the VSWR of antennas used at HF/VHF band. Some novel electrically small antennas and wide band antennas such as hybrid loaded monopole, open-circuited transmission line loaded antenna and wire-taper antenna are designed according to these effective technologies found before.Moreover, the matching circuit of electrically small antennas using transmission line is studied in this dissertation. A model is presented. And some theory analyses and the measure result are given.