Scattering Performance Optimization Of Microstrip Antenna Based On Chessboard-like Artificial Magnetic Conductor Array

Stealth,which is usually appears at the fiction film,is trying to lurk in people's lives.Lower scattering echo was achieved for the aircraft based on stealth technology,but the antenna in aircraft,as an essential combination of scattering and radiation source,is a great contributor to the overall scattering,result in the bottleneck of anti-radar stealth technology.Besides,differ from the other scattering target,the tradeoff between radiation features and radar cross section(RCS)reduction should be taken into consideration,which brings up many challenges.RCS reduction is reached by integrating metamaterial with antenna,followed by the diffraction or absorbing the incident electromagnetic wave.Stealth are achieved on the basis of radiation retention,even enhanced the radiation performance.Metamaterials are the structures artificially engineered to realize unusual effective electromagnetic macroscopic properties not yet found in nature.In addition to the metamaterial antenna,nowadays,electromagnetic metamaterials have been widely infiltrated into aerospace,wireless communication,military equipment and other related fields.The ultra-band RCS reduction within entire frequency band is hard to realize because of the bandwidth limitation of artificial magnetic conductor(AMC),here we propose a new method that out-of-band characteristic of AMC and effective reflection phase difference are integrated into a chessboard-like reflector to extend the RCS reduction bandwidth.First,the feasibility of out-of-band RCS reduction and effective reflection phase are described in theory,and the electromagnetic simulation software HFSS is applied to optimize the behavior of AMC,with which the tight junction of effective reflection phase difference and out-of-band frequency are achieved.The 10 dB RCS reduction of chessboard-like AMC reflecting screen,composed of different square patches AMCs blocks,is extended from 12.1 GHz ~ 20.5 GHz(51.5%)to 13.7 GHz ~ 27.6 GHz(67.3%)compared with the same sized perfect electric conductor(PEC).Besides,the improvements of reflection magnitude,oblique incidence stability and arrangement of AMC units are completed.Furthermore,the chessboard-like configuration,consists of 3 × 3 AMCs block arrays,is loaded around the microstrip patch.The composite antenna realizes a dramatic 10 dB RCS reduction in-band and out-of-band over the entire band of 13.4 GHz ~ 26.9 GHz(67.0%),covers the K band and Ku band.Moreover,the relative bandwidth is kept by change of surface current path,as well as the impedance matching,and the radiation efficiency of the composite antenna is enhanced due to property of approximately parasitic patch.The proposed low-RCS microstrip antenna and conventional patch antenna are manufactured and measured.The measured monostatic RCS of the reference antenna is obviously reduced by more than 10 dB within 13.5 GHz ~ 28.1 GHz(70.2%),except for a few points,coincide well with the simulated counterpart,the validity of out-of-band reduction are proved in theory and experiment.Finally,main work and innovations of this paper are summarized,and the inadequacy and development are also described and expected.