Broadband Low-noise Testing And Noise Source Calibration System

The RF and microwave noise consist in the all wireless system. It is very important that pricisly test noise parameters and research the noise metrolonogy techniques. This article presents the development of the wide-band noise test and noise source calibrate system of CETC10.The project adopt the method that integrate the system by the primary standard noise source which based on the thermodynamics principle ,LNA, isolators,and wide-band noise receivers.The system finally constituted successful and the frequency range covered 10MHz to 40GHz. The system has two main functions that is low noise figure test and the solid noise source ENR parameter calibrate. The system can test low noise temperature from 20K, and the measurement uncertainty is 15% . And that the system calibrate noise source ENR value uncertainty is less than 0.4dB for the whole frequency band .The article first explained the basic theory of the microwave noise. Summarized and analysised the noise test methods. Then introduced process of developed the system by the basic test theory. In the project, the research group also developed the controller and remote interface, wrote the auto test program and designed the system structure.All the techniques ensured the system's accuracy, stabilization and repetition. Through in-depth research and experiment, the project solved the two key questions that standard noise source efficial output noise temperature measurement and reducing the receiver linearity influence. At last, through the comparison of testing , the result of the experiment, and the uncertainty analysis, the article evaluated the system's performance.