FIELD: physics, radio.
SUBSTANCE: invention relates to radio-measuring techniques, specifically to measurement of nonlinear distortions. A first operational amplifier at any frequency shifts a sinusoidal signal by 90 degrees which, using a second operational amplifier and potentiometres enables to obtain signals with phase varying in the -90…+90 degree interval at the output of the measuring device at any frequency. Amplitude of the signal is regulated using a third and a fourth operational amplifier. The signal amplified by the fourth operational amplifier from the output of the measurement object is smoothed by selecting amplitude and phase with the signal at the output of a differential amplifier, and minimal readings are obtained at the device for measuring effective values, where the said readings are nonlinear distortions caused by the object and essentially by the measuring device and can also be measured separately by connecting its input to the output.
EFFECT: preventing dependency of the value of phase shift on frequency in an amplifier - phase shifter.
