Research On V-band Portable Reflectivity Measurement Technology

V-band has great significance in radar,communication and medical treatment,and has great potential in the application of biological tissue reflectivity test.Reflectivity is a key microwave parameter that reflects the absorbing properties of materials.At present,the V-band reflectance is mostly tested in the laboratory environment by vector network analyzer.In the process of using,the equipment is required to adapt to the field environment,and there are few test technologies that can be portable for near-field test.Therefore,the development of this subject is of great significance.This thesis firstly analyzes the theory of reflectivity laboratory test technology and portable reflectivity test technology,and analyzes the antenna near-field test technology and the measurement principle of single reflection method.and designs a portable nearfield reflectance measurement system for V-band(57?64 GHz)based on these theories.According to the antenna principle and system performance,under the premise of ensuring small system volume,the simulation and measurement results of the horn antenna and the lens antenna are compared,and the antenna with narrower near-field radiation beam is designed and selected.Important microwave devices in the system were developed,including a rectangular-circular transition,a coaxial-waveguide transition,and a directional coupler.Then,a test system consisting of a lens horn antenna,the abovementioned microwave devices and a portable reflectivity detection instrument was designed and integrated.The portable reflectivity detection instrument is integrated by the KC901 Q vector network low-frequency vector sweeping module and the spread spectrum module.The reflectance detection instrument obtains data through the antenna and the data is fed back to the single-chip microcomputer.After reading the relevant data,the single chip microcomputer stores and displays the data.After evaluating the test dynamic range and consistency of the system,based on the biological electromagnetic effect that V-band electromagnetic wave penetrates the skin but does not significantly penetration of subcutaneous tissue,the test system is applied to skin burn detection,which takes advantage of the high sensitivity of the interaction between V-band electromagnetic wave and skin.This is a new functional detection method.After testing some samples,the test results are shown and analyze the errors existing in the testing process.The millimeter-wave portable test system developed in this thesis has the characteristics of accurate test results,convenient and simple test process,good system stability and wide application potential.