Study Of A Conformal Dual-polarization Antenna Array

In recent years,with the continuous improvement of aircraft radar systems and the continuous development and improvement of microelectronic technology,the requirements for the functions of aircraft radar systems have become higher and higher.Thus,the antennas in the radar system need to develop in the direction of multi-polarization,large airspace,and conformal arrays to increase anti-jamming performance and combat multipath fading.Therefore,the research on the characteristics of the conformal dual-polarized antenna array has very far-reaching significance.Combining the development needs of aircraft radar systems,this paper takes dual-polarized antennas,wide-angle scanning and conformal antennas together as the research objects.The paper studied antenna dual-polarization technology and conformal phased array technology,we comprehensively design a conformal phased array with dual-polarization performance.The paper takes the point,line and plane as the overall research idea,starting from the antenna element design,to the linear array design,and then to the conformal array design to complete the research work.The main contents of the paper include:Frist,based on the principle of the Yagi antenna and combining the design principles of dualpolarization antennas,two antenna elements suitable for wide-angle scanning were designed.The two antenna elements were simulated and analyzed.Then,antennas is fabricated and measured.Measured results shows that both dual-polarized antenna elements can meet the established performance indicators.Comparing the two antenna elements,it can be found that the single-layer dual-polarization antenna element has a better performance in isolation and dual-polarization.Compared with the double-layer antenna,the bandwidth is 2.25 times that of the double-layer antenna element,with higher port isolation,lower cross-polarization level,wider 3d B beam width,and the radiation performance of the two orthogonal polarizations has good consistency.Second,the single-layer microstrip Yagi dual-polarized antenna is arranged in a special rotating array and the one-dimensional 16-element wide-angle scanning linear array is designed.When two groups of orthogonally polarized elements are fed separately,the active return loss of each array element is good.Its main beam can achieve wide-angle scanning of-65°-65° in one-dimensional plane.Its 3d B beam coverage is basically the same,and the maximum coverage is-76.19°-73.53°,which can basically cover the upper half of the antenna array.What's more,the antenna array has small gain fluctuation and good polarization performance is maintained during the scanning process.Third,based on the improved array method aligned along the bus bar of the frustum,a 40-element double-layer frustum conformal dual-polarized antenna array is designed.When two groups of orthogonally polarized elements are fed separately,the main beam can achieve a wide-angle scan of 10°-140° in the elevation plane.Its 3d B beam coverage is basically the same and the maximum coverage is 2.17°-148.60°,which can completely cover the upper space of the frustum conformal array.At the same time,the two groups of orthogonally polarized main beams all reach the maximum gain when scanning to 75° and the maximum gain is 21.23 d Bi.On the whole,the conformal antenna array has low sidelobe level,relatively high gain,small gain fluctuation,and good polarization performance is maintained during the entire scanning process.