A zero-level stabilization and baseline restoration device

Abstract

For stabilizing the zero level at the output of a linear amplifier, use is made of an external negative feedback including an aperiodic circuit and dc amplifier. Such a feedback converts the linear amplifier to a differentiator amplifier, which gives rise to errors in measuring the amplitudes of pulses occurring at short time intervals. In order to diminish errors in measuring amplitudes of frequently recurrent pulses, in the present work the feedback circuit is complemented to a nonlinear network which clips the amplitude of pulses fed to the input of the aperiodic circuit. Values of the errors of the device with and without a nonlinear network and with additional correction for a periodic train of square pulses have been calculated. The circuit diagram of the device including a limiter and a compensating amplifier is presented.