噪声系数测试仪的原理及毫米波扩频测试技术

Principle and Millimeter Wave Frequency Expanding Measurement Technology of Noise Figure Meter

Agilent8970B噪声系数测试仪是低噪声、高灵敏度接收机,与Agilent8971C扩频装置、本振一起使用,可以将测试频率扩展到26.5GHz。介绍了其原理及测试方法,该方法通过外加变频器将频率扩展到毫米波(40GHz),实现了毫米波组件的噪声系数测量,并且对该毫米波系统噪声系数进行了测量结果不确定度分析,噪声系数测量不确定度为0.55dB。噪声系数测量不确定度与被测件的噪声系数及输入、输出驻波比关系密切,因此在工作中对仪器的选择,连接件的连接显得至关重要。对毫米波噪声系数测量系统进行了大量测试,很好地满足了毫米波噪声系数的测试需要。

HP8970B noise figure meter is a low noise, high sensitivity receiver. It can be used with HP8971C noise figure test set and local oscillator （LO）, expanding measurement frequency to 26.5 GHz. The principle and measuring method of the noise figure meter were described, with a second external LO, measurement frequency can be extended to 40 GHz. It realized noise figure measurement of millimeter wave, measurement uncertainty of the millimeter wave system was also analyzed. The calculated noise figure measurement uncertainty is 0.55 dB. The measurement uncertainty of noise figure is related to the noise figure of DUT, input ＆ output standing wave ratio, so the choice of instrument, connectors is very important. Lots of measurements can be down with this millimeter wave measurement system, it can well meet the need of millimeter wave noise figure measurement.