Research On Multi-octave Broadband Antenna And Its Array

At present,the research on multi-octave broadband antenna and its array in the antenna field are more and more thorough.Vivaldi antenna is a kind of tapered groove line-type end-emitting traveling wave antenna,with wide frequency band,directional radiation characteristics and relatively stable phase center,and simple structure,easy to process and integrate,suitable for ultra-wideband wireless communication system.In this paper,the Vivaldi antenna and its array are analyzed and studied.In this paper,the main work can be divided into the following several aspects:First of all,based on the three loading techniques of rectangular slot line loading,resistance loading,resistance and parasitic conductor hybrid loading,three miniaturized Vivaldi antenna units working in the frequency band of 6-18 GHz are designed,and their radiation characteristics are analyzed and discussed in detail.The Vivaldi antenna based on rectangular slot line loading can be reduced by about 20% compared to the Vivaldi antenna size in other literatures.And the size of two types of Vivaldi antenna units based on resistance loading and resistance and parasitic conductor hybrid loading can be further reduced by more than 40%.Then a high-gain Vivaldi antenna unit is designed based on the artificial electromagnetic material loading of the parallel line structure,with a maximum gain of 11.2 d Bi and a minimum gain of 6.2 d Bi.Then,the rectangular slot loaded Vivaldi antenna unit is processed and tested,the test results show that the VSWR of the antenna is substantially less than 2 in the whole working frequency band.In the azimuth plane,the gain of the antenna in the normal direction is greater than 5d Bi,and the gain of ±45° from the normal direction is greater than 3d Bi,and the front-to-back ratio of the antenna is greater than 10 d B.The antenna has good ultra-wideband characteristics and good cross polarization and good directional radiation characteristics in a wideband.Finally,based on the Vivaldi antenna unit loaded with rectangular slot lines,different forms of ultra-wideband array antennas are designed.Firstly,a 12-element Vivaldi array antenna with equal array spacing is designed,and then a 12-element Vivaldi array antenna with unequal spacing between array elements is designed under the same antenna aperture.Compare the radiation characteristics of array antennas in two different arrays.Finally,a 19-element sparse array antenna with a "ten" shape structure with two-dimensional scanning ability is designed.In order to better receive electromagnetic energy,the array elements are tilted at 45°.And the array is processed and tested,the simulation results are consistent with the test results.The results show that in the range of 6-18 GHz,the active standing wave ratio of the array is less than 2.5,and it has a better beam scanning characteristics in the azimuth plane and the pitching plane.