In Ref. [1]

we have established a new noise circuit theory

its advantages make the accuracy and efficiency of noise performance analysis and low-noise design to be greatly improved. In this paper

the experimental study on this noise circuit theory is described and its advantages are verified. Compared with other noise measurements

the noise spectrum measurement system given in this paper has the advantages of measurement overall low-frequency noise spectrum

accuracy higher than 4% and automatic operation. Moreover

the extracting problem of noise parameters of active devices or circuits is easily solved. Lastly

a pratical example of theoretical and testing results is given and compared with each other.