Research And Design Of Low-Scattering Planar Antenna

The stealth technology has received extensive attention because of its key position in military field.With the development and maturity of stealth technology,the scattering issue of antenna,which is a kind of special scatter,becomes the key problem of its carrier.To ensure the normal communication between different equipment and to avoid being detected by the enemy's radars,the antennas of these equipment require to reduce their radar cross section(RCS)as much as possible while their radiation characteristics to be well kept.Microstrip patch antenna,which is low profile,light weight and easy conformal,is widely used on high-speed aircraft.Take rectangular patch antenna as an example,RCS reductions of antenna and antenna array are realized by loading CSRRs on the ground or around the radiation patch of the antenna.The research provides guiding significance for the other planar antennas such as slot antenna.The main work of this thesis is concluded as follows:1.Utilizing the deflective characteristics of the scattering wave and the polarization selectivity of the incident wave while the CSRR is resonant,two CSRRs are loaded on the ground of the microstrip antenna.The CSRRs are placed perpendicularly to each other,which achieve scattering reduction in both x-polarization and y-polarization,and the result of measurement is consistent with that of simulation.2.Using the relationship between the resonant frequency of CSRR and its circumference,two CSRRs with different stem lengths are loaded on the non-radiation side of the microstrip antenna,which can achieve a wideband scattering reduction.The frequency band of the RCS reduction is 2.48GHz-3.32GHz.3.Based on the previous study of CSRR,a kind of double stems internally-extended in CSRR(DSI-CSRR)structure is designed.The new structure increases one resonant frequency in x-polarization and y-polarization separately,which makes it equals to two CSRRs.An orthogonal chessboard reflection screen is designed by the principle of reflective phase difference.The RCS reduction frequency band of the screen is 7.5GHz-14.5GHz,among that,in 9.4GHz-9.9GHz,10.5GHz-11.2GHz and 13.8-14.1GHz,the RCS reduction is more than 10dB.Simlation and measurement get the same results.4.Load the chessboard structure of the above-mentioned DSI-CSRR around radiation patch of the microstrip antenna array,and the RCS of the antenna array will be reduced in multiband.