极低噪声测试系统的方法研究

Research of the methods for the ultra-low-noise test-system

介绍了可变负载温度法和低温衰减器法。两种方法都应用了所谓的Y因子测量技术。当前S波段致冷放大器的噪声温度已达到小于7K的水平。测量如此低的噪声温度,对于电缆的损失、衰减器和接头以及仪器和传感器的校准,必须给予极大的关注。两种方法噪声温度的测量已经被应用并作了比较,整个测量的估值精确度小于1K。

This paper introduced the variable load temperature method and the cold attenuator method.Both employ so called Y-factor measurement technique.At present,the noise temperatures of S-band cooled amplifiers have reached less than 7K.When we measure such a low noise temperature,great care has to be taken in order to measure cable losses,attenuators,connectors,calibration of instruments and sensors.Two methods of noise measurement have been used and compared and the overall accuracy of the measurement estimated is less than 1K.