Digital low frequency correction circuit and method for reducing low frequency disturbances within a digital signal

A measurement frontend of a measurement apparatus, said measurement frontend comprising

• an analog signal amplifier adapted to amplify a captured analog measurement signal to generate an amplified analog signal,
• an analog to digital converter, ADC, adapted to convert the amplified analog signal to provide a corresponding digital signal and comprising
• a digital low frequency, LF, correction circuit used for correction of low frequency, LF, disturbances within the digital output signal of the analog to digital converter, ADC, said digital low frequency, LF, correction circuit comprising:
• a main signal path adapted to delay the digital input signal received by a signal input terminal of said low frequency, LF, correction circuit,
• a correction signal path including a digital correction filter adapted to filter the received digital input signal and
• an adder adapted to add the digital signal delayed by the main signal path and the digital signal corrected by the digital correction filter of said correction signal path to generate a digital output signal output by a signal output of said low frequency, LF, correction circuit to a processor of said measurement apparatus.

A method for reducing low frequency, LF, disturbances within a digital signal, comprising the steps of

• receiving the digital signal as a digital input signal;
• processing the received digital signal by delaying the received digital signal with a predetermined delay and filtering in parallel the received digital signal by a digital correction filter;
• and
• adding the delayed digital signal and the filtered digital signal to provide a digital output signal with reduced low frequency, LF, disturbances,
• wherein the digital signal is received as digital output of an analog to digital converter, ADC, which digitizes a low frequency amplified analog signal received by said analog to digital converter, ADC, from an analog signal amplifier, and wherein the amplified analog signal includes low frequency disturbances equalized by said method for reducing low frequency, LF, disturbances.