Study On Theory And Realization Scheme Of Metric Wave Ultra-wideband Dual-polarization Plasma Antenna

In modern warfare,traditional radar is facing new threats such as stealth technology,anti-radiation missile?ARM?and low-altitude penetration,the new type of metric wave antenna with wideband,multi-polarization and agility becomes a new requirement in modern radar confrontation.In this paper,a new type of metric wave antenna theory and implementation scheme is studied based on plasma antenna technology and reconfigurable antenna technology,and some theoretical and engineering achievements are obtained.Based on design index of the metric wave ultra-wideband vertical polarization plasma antenna proposed by our project team,combined with the thought of double sleeve broadband and transmission line step impedance conversion broadband,a prototype of the vertical polarized antenna with the UWB impedance characteristics is designed.Then,the scheme of adding ground plane and the scheme of pattern reconfiguration based on the plasma are proposed,to solve the low-angle performance deterioration because of non-ideal earth reflection and pattern crack since the antenna is working in ultra-wideband,respectively.The simulation results of designed metric wave UWB vertical polarization plasma antenna satisfies the requirements of S₁₁<-10dB in 30¹00MHz,and performs well at low elevation.Based on design index of the metric wave horizontal polarization plasma antenna proposed by our project team,referring the design of waveguide slot antenna,metric wave horizontal polarization plasma antenna resonating at 118.5MHz is designed by slotting over the sleeve of the existing vertically polarization antenna and adopting probe feed structure,and good isolation between the vertical polarization operation mode and horizontal polarization operation mode is got in theoretically.In view of the narrow band characteristics of the horizontally polarized radiation,two broadband schemes are proposed:one is reactively loaded,and the simulation relative impedance bandwidth can be increased to20.7%;the other is sweep-band broadband method based on dielectric filling and plasma reconstruction,and the simulation antenna band can be extended to 44¹10MHz.Moreover,the radiation mechanism of the horizontal polarization is theoretically analyzed,and the equivalent circuit model of the transmission line is established.The full-scale metric wave vertical polarization antenna is processed and measured,and the measurement results show that the antenna basically accorded with the project requirements.In addition,the scaled metric wave vertical polarization in 1:10 ratio antenna is processed and measured,and the measurement results prove the rationality of horizontal polarization radiation implementation scheme.In summary,a kind of metric wave ultra-wideband dual-polarization plasma antenna which may be used in modern radar is presented and realized in this paper;the vertical polarization operation mode and horizontal polarization operation mode share the same radiator structure,and good isolation between two modes is got.In addition,the radiation theory of the horizontal polarization is analyzed,and the equivalent circuit model of the transmission line is established.It has certain theoretical and practical value.