Research For Radar Cross Section In Terahertz Of Two Calibrators

Radar cross section(RCS),as an important radar characteristic parameter,is of great significance for target detection,recognition and classification.The traditional radar cross section measurements mainly use the centimeter wave as radiation source,its corresponding frequency is GHz,belonging to the microwave band.According to the scaling principle,the electric sizes of the target and the scaled models should be same,so that the physical sizes of the models should be reduced according to the same scale,and the measuring wavelength should be reduced and the frequency should be broaden according to the same scale.So the terahertz RCS should be studied.In this paper,the measurements of terahertz radar cross section has been discussed mainly from the following aspects.(1)Based on the basic knowledge,classifications and applications of the radar,the concept of radar cross section is introduced as well as the resent research conditions,the basic principle of RCS,prediction methods and measurement methods.(2)This paper analyzes two kinds of measurement methods to get the terahertz radar cross section.One is full-scale measurement and the other one is compact radar range of scalemodel tactical targets.We discuss the advantages and disadvantages of two measuring methods,and according to the principle of scaled measurement,the 0.1 THz continuous wave measurement system for Radar cross section has been built.In this paper the Gunn diode oscillator is used as the terahertz radiation source,and we have introduced the process of building this system.(3)Taking the metal plates and metal reflectors as an example,the metal plates,the dihedral corner reflectors,the square trihedral corner reflectors and the triangle trihedral corner reflectors in different sizes are studied.We have done some theoretical calculations and simulations to obtain the theoretical values which are compared with the experimental values.By analyzing the errors and the reasons for the errors,we can verify the performance of the system.What is more,the scattering mechanism of metal plates and metal reflectors are researched as well as the scattering patterns,which provide theoretical guidance for the followup study of terahertz radar cross section.(4)The radar cross section of F22 model is measured,and the experimental result are in good agreement with the physical model of aircraft and the validity of the system is verified.