A relatively simple automatic Noise Figure (NF) meter was developed which is using a spectrum analyser as the receiver and logarithmic power detector.
The circuit makes use of the X and Y output signals available on most spectrum analysers. It processes these signals to control a noise head and obtain Y, Gain and NF values that are displayed on digital or analogue meters.
This simple instrument will enable easy real time alignment and optimization of preamplifiers and converters for best performance, on the full range of the noise head and spectrum analyser.
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