Research And Design Of Frequency Absorption And Selection Radom Based On Broadband Wave Penetration

With the development of radar detection technology,the traditional stealth radome can not meet the requirements of the current communication environment.More and more fields are in urgent need of new comprehensive stealth radome.The traditional stealthy radome(with pass-frequency selection)can allow the electromagnetic wave to pass through in the working frequency,and reflect the electromagnetic wave outside the working frequency to other directions,so as to realize the single station stealthy radar antenna system.However,the omnidirectional stealth function is lost for dual-station or multi-station radar scenarios.And once the traditional radome is made,its working band can no longer be adjusted and changed,so it does not have flexibility and can not better adapt to today’s complex communication environment.In this paper,Frequency Selective Absorptive Surface(FSAS)structure is proposed.The structure can not only transmit the electromagnetic wave in the passband,but also show great advantages in absorbing the electromagnetic energy reflection outside the passband.It can absorb the electromagnetic signal outside the passband,realize the weak reflection outside the passband,and reduce the scattering cross section(RCS)of the antenna radar.This topic is mainly designed from the following research points:This topic is mainly designed from the following research points:Research point 1:A single frequency transmittance low RCS radome based on absorbing frequency selection unit structure is designed.The principle of passband transmission in absorbing band and its equivalent circuit are analyzed,and a three-layer cell structure model is designed.Finally,it realizes wave transmission in 3.3GHz～3.9GHz band and wave absorption in 2.8GHz～6.4GHz band.The effect of single frequency band transmission in absorbing band is achieved.Research point 2:A dual-frequency transmittance low RCS radome based on absorbing frequency selection unit structure is designed.This paper mainly studies how to construct the double-pass band frequency selective surface(FSS)and how to improve it based on the first model.Finally,the wave penetration effect is realized in 5.7GHz～7.8GHz and 10.7GHz～11.9GHz,and the wave absorption is realized in the band range of 5.6GHz～12GHz,which covers the whole transmission band and the frequency band on both sides of the transmission band,effectively reducing the reflection of electromagnetic wave outside the passband.Research point 3:A passband reconfigurable cell structure is designed.This paper mainly introduces the function of PIN diode and varactric diode,through the joint modulation of PIN diode and varactric diode,under the premise of ensuring low reflection effect,the adjustment of the wave transmitting frequency band is realized,and finally realizes the wave transmitting adjustable in 1GHz～1.4GHz,and 3.2GHz～4.17GHz.