Method for measuring ultralow distortion degree

Abstract

The invention provides a method for measuring an ultralow distortion degree. The method comprises the following steps: attenuating a fundamental component of a sine signal before accessing the signalto a frequency spectrum analyzer, namely adding a primary fundamental wave network before the sine signal enters the frequency spectrum analyzer and enabling a harmonic signal to pass through withoutattenuation, so as to measure the ultralow distortion degree. The method is a fundamental wave inhibition and frequency spectrum analysis method; and according to the method, the advantages of a fundamental wave inhibition method and a frequency spectrum analysis method are synthesized, the measurement lower limit of the ultralow distortion degree can be effectively reduced to minus 130 dB, and the problem that the ultralow distortion degree cannot be measured accurately is solved.

Description

technical field [0001] The invention relates to the field of distortion measurement of radio electronics, in particular to an ultra-low distortion measurement method. Background technique [0002] Among radio parameters, nonlinear distortion is a very important parameter. At present, the instruments for measuring distortion can be roughly divided into two categories according to the measurement principle: fundamental wave suppression method and spectrum analysis method. When the fundamental wave suppression method is used to measure the distortion degree, due to the influence of the depth of the fundamental wave suppression of the distortion meter and the distortion introduced into the machine, the lower limit of the measurement of the distortion meter is limited, usually it can only reach -60dB~-80dB. When the spectrum analysis method is used to measure the distortion, due to the limitation of the spectrum analyzer's own distortion and dynamic range, the measurement lower ...

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Problems solved by technology

When measuring the distortion by the fundamental wave suppression method, due to the influence of the fundamental wave suppression depth of the distortion meter and the distortion introduced into the machine, the lower limit of the measurement of the distortion meter is limited, usually only -60dB ~ -80dB

When measuring the distortion by the spectrum analysis method, due to the limitation of the spectrum analyzer's own distortion and dynamic range, the measurement lower limit usually only reaches -70dB~-80dB

Therefore, neither of these two methods can be used for ultra-low distortion measurement

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