Research On New Generation Communication Radome Based On Artificial Electromagnetic Frequency Selective Structure

Communication technology plays an important role in modern information industry.With the high-speed development of communication device,the antenna system tends to work in millimeter wave and has features of miniaturization,multi-band,and large band ratio.Since traditional radome has limited ability in controlling the electromagnetic wave,the development of new generation antenna systems is facing severe challenges.In order to meet the high performance requirement of the novel antenna system,it is necessary to explore the application of artificial electromagnetic frequency selective structure(FSS)in radome design.However,there are still many technical challenges in the study of radome based on FSS:1)Most of the traditional FSS radome works in a relatively low frequency band below 20 GHz,and rarely has all the characteristics of wide bandwidth,deep out-of-band suppression and sharp roll-off.2)For the 2-D FSS radome,the response degradation is observed when the incident angle is larger than 40 degrees.3)The metal line elongation of the traditional 2.5-D miniaturized FSS radome does not increase significantly.4)The t:raditional dual-band,transmission FSS radome cannot provide a large band ratio(BR)performance.5)For the 2-D dual-band and large BR FSS radome,the response begins to degrade when the incident angle exceeds 30 degrees.For the first challenge,a radome based on 2-D FSS is proposed for 5G communication.Measured results show that the-3 dB bandwidth covers 24.96 GHz to 30.90 GHz,and the out of band suppression is larger than 25 dB.In the meanwhile,the corresponding equivalent circuit model and analytical formulas are presented.The transmission poles derived from full-wave simulation and circuit model have a maximum deviation of less than 1.0%when compared with the measured resultsFor the second challenge,a radome based on 2.5-D FSS is designed.Measured results show that the-3 dB bandwidth covers 26.42 GHz to 29.08 GHz,and the out of band suppression is larger than 20 dB.It is worth to mention that the frequency response is still stable when the incident angle changes up to 60 degrees.Then,the corresponding equivalent circuit model and analytical formulas are presented.The transmission poles derived from full-wave simulation and circuit model have a maximum deviation of only 0.30%when compared with the measured resultsFor the third challenge,a miniaturized radome based on 2.5-D FSS is proposed.Measured results show that the unit cell size of single-band and dual-band FSSs is only ?0/34 and ?0/27.Stable frequency response under various angles up to 60 degrees is obtained.In addition,the equivalent circuit nodel of single-band FSS is presented.Favourable agreement is achieved between sinulation and measurementFor the fourth challenge,a radome based on 2-D dual-band and large BR FSS is proposed.Simulated results show that the design example can provide two transmission windows with center frequencies of 1.0 GHz and 15.0 GHz,and the BR value is achieved up to 15.0.The-10 dB fractional bandwidth of 167.8%is realized The corresponding equivalent circuit model and analytical formulas are also presented.Moreover,the measured BR value is 15.3 and the-10 dB fractional bandwidth is obtained as 164.3%.For the fifth challenge a radome based on 3-D dual-band and large BR FSS is proposed.Simulated results show that this design can provide two transmission windows with center frequencies of 1.2 GHz and 15.0 GHz,and the BR value is acmeved as large as 12.5,At the same time,stable frequency response under various angles up to 60 degrees is obtained.Then,a corresponding equivalent circuit model is presented.Finally,a dual passband,large band ratio and absorptive radome is realized by the hybrid 2-D and 3-D FSSs.A wide absorption band with a fractional bandwidth of 102.9%is created between two transmission windows.