Design And Research Of Frequency-selection Radome Based On Rasorber

In recent years,as the radar technology plays an increasingly important role in modern warfare,the electromagnetic stealth technology is becoming the hotpot of the electromagnetic fields in the world.As we know bandpass frequency selective surface is often used in the research and design of radome.However,the traditional FSS radome can only reduce the mono-static RCS of the antenna.In other directions,it still has a strong out-of-band reflection,which results in an increased RCS.Hence,the traditional FSSs may be detected by bistatic or multi-static radars.Therefore,a new ideal radome was proposed to compensate for this deficiency,which is nearly transparent at the passband while the wave can be absorbed by the structure out of the passband.This new structure is denoted the frequency-selective rasorber(FSR).The word “rasorber” is the combination of “radome” and “absorber,” and is a type of radome that functions as an absorber.The FSR is a rasorber that has a transmission and an absorption band,retaining the advantages of the FSS and the absorber,while the FSS only shows the characteristics of spatial filter and cannot absorb out-of-band total reflection of the incident wave.This paper presents a miniaturized frequency selective rasorber(FSR)with both wide absorption and transmission bands.The proposed FSR consists of a resistive sheet and a band-pass frequency-selective surface(FSS)with non-resonant constituting elements.The unit cell structure of the resistive sheet is a meander line loaded with four lumped resistors,which generate a wide absorption band from 2.4 to 6.2 GHz,while the layers of FSS are coupled resonator spatial filters(CRSFs)that generate a wide transmission band from 7.5 to 10.2 GHz.Furthermore,there is a 9.5mm air spacer between the resistive and FSS layers.The period of the FSR structure,which maintains its passband and absorption band performance,is only 10 mm(0.08 ?L).Simulated and measured results are compared and found to show good agreement.Finally,in order to validate the correctness of the simulated results,a prototype was fabricated using printed circuit board(PCB)manufacturing process.Besides,the comparison with the recently published work is shown to demonstrate the performance of the proposed FSR.