Ultra-wideband Tem Horn Antenna Array Radiation Characteristics Of A Preliminary Study

This dissertation is mainly concerned about the radiation of the TEM-horn arrays which radiate UWB(ultra wideband) pulse, It mainly involves three parts: theory, numerical stimulation and experiment.The UWB antenna is a new research field in the world which has many differences from NB(narrow band) antenna. The most difference is that the UWB antenna such as TEM-horn radiates nanosecond pulse which has wide frequency spectrum, but the NB antenna radiates single frequency signal. The research of NB antenna array is mature, but the research of UWB antenna array is only beginning. With the developing of new switches such as photoconductive switch and SOS(solid opening switch), both high power and high gain can be got by the UWB antenna array.Firstly, we review the history of UWB antenna, and introduce the background of UWB antenna array research.Then, Using the opening transmission line model, the deduction of the TEM-horn antenna far-field radiation formula is introduced .Comparing with the traditional NB antenna array, The brief theory of UWB antenna is analyzed.Thirdly, one numerical stimulation method-FDTD(fmite-Difference Time-Domain) and the transformation of near zone to far zone are introduced, and then the program is verified. Using the simulation program, far zone radiation of TEM-horn array is analyzed. The result of analysis proved that the mutual coupling between elements of array did not affect the main radiation wave of very much. When the element of array is near enough, the stacked TEM-horn array can improve the radiation of lower frequency. Just as NB antenna array the pattern of UWB TEM-horn antenna array is concern with the number and distance of elements at which the pattern lie in. Changing the feeding time delay of element can controlled beam steering.Finally, the experiment research has been done. Four TEM-horn antennas have been made. Using these antennas two-element rain gutter TEM-horn array, two -element stacked TEM-horn array, four-element rain gutter TEM-horn array and four-element stacked TEM-horn array are been mades up of. The results of experiment accord with theory and numerical stimulation.