Study On Measurement Technology Of Radiation Characteristics Of 3mm Band In Fiber Fabric

As an important aspect of the invisibility and security technology research, the study on fabric’s radiation characteristics of Microwave radiometry provides theoretical basis for the development of camouflage coating and target detecting and recognition. Based on the millimeter-wave radiation metrology, this paper studies the fabric’s radiation characteristics in 3 mm wave band measurement.Firstly, the paper expounds the measuring principles and methods of the fabric’s radiation characteristics in 3mm wave band measurement. Radiation metrology and the basic theory of millimeter-wave radiation characteristics are introduced, which provides the basis for fabric millimeter-wave radiation characteristic measurement; noise-adding millimeter-wave radiometer is studied, and the setting time of the radiometer system’s output reached the ADC’s resolution is analyized. Models are established for the millimeter-wave radiation characteristics of single and double fabric; measurement and calculation methods of the fabric’s radiation characteristics in 3mm wave band measurement are given.Secondly, the fabric’s radiation characteristics in 3mm wave band measurement hardware and software are designed. Every part of the noise-adding millimeter wave radiometer is designed, including the radiometer antenna, the RF front-end for radiometer, intermediate frequency amplifier, square law detection, low frequency circuit, and simulations by software are done for the radiometer antenna, intermediate frequency amplifier, square law detection and low frequency circuit. The main indices of each part are given, and each module such as data acquisition and stepper motor control is designed. Software testing is done and data measurement and motor control of the upper machine are designed.Finally, experiment on the fabric’s radiation characteristics in 3mm wave band measurement are carried out on and indices of the radiometer system are tested. Two sets of experiment platform which respectively test intermediate frequency amplifier stability test and the fabric’s radiation characteristics in 3mm wave band measurement are set. Analysis of the performance of millimeter-wave radiometer indices, including the stability of the intermediate frequency amplifier and radiometer system, integration time, sensitivity and the absolute accuracy and so on, are all given, Also, integration time in both software and hardware system for the radiometer is analyzed. On this basis, the fabric’s radiation characteristics in 3mm wave band measurement experiment are carried out. The experimental results are calculated, and analysis on the influence of millimeter-wave radiation measurement for fabrics affected by observation error of the light temperature radiometer is presented.