Impact of Receiver Bandwidth and Nonlinearity on Noise Measurement Methods [Application Note]

The article has dealt with problems of noise measurement located on the receiver side. The influence of noise bandwidth B and receiver gain GREC on the measured power level FNwas discussed. The digital realization of B enables a revival of the signal generator method. The need for a calibrated noise generator is eliminated and a VNA can be used a receiver. A transistor measurement shows that the linearity of the receiver is extremely important. Through the application of the cold-source method, this influence can be significantly reduced.