Research On Microwave Radiometer Characterization Testing System

In this dissertation, general research situation of both domestic and international microwave radiometer calibration and characterization testing technologies are introduced. Deep theoretical analyses are carried on several key questions like radiation characteristic of calibration load, near-field pattern of horn antenna and so on. Calculations are done on the base of analysis. Detailed and intuitionistic results are given. Based on the definitions of microwave radiometer characterization parameters and the test methods presented in this paper, tests have been done. Structure of calibration load with temperature naturally varying is studied in the research of radiation characterizations of calibration load. Using coherent and incoherent methods of radiation output brightness temperature, relationships between the load output and the thickness of insulated foam layer, output brightness temperature and angle of incidence are found. Using FDTD and aperture field integral methods, near-field radiation pattern of horn antenna is derivate. It is helpful to the precision research of radiation characterization testing. Ameliorations are done to the ground base small antenna aperture MWR calibration system and a complete MWR characterization testing system is designed. Using the system, 8 mm radiometer characterization testing experiments are done. Calibration equation and characterizations of the radiometer such as linearity, sensitivity, stability and integration time are obtained.