Patent attributes
This disclosure concerns an amplitude detector comprising: a maximum-minimum detector detecting a maximum and a minimum values of a digital signals; a first and a second lowpass filters respectively having a cutoff frequency lower than a frequency of the waveform signal; a cycle detector detecting a cycle of the waveform signal; a correction coefficient generator generating a numeric value of a correction coefficient expressed by a calculation with respect to the cycle of the waveform signal and a cycle of the sampling; a first multiplier generating a corrected maximum value by multiplying the maximum value of the digital signals by the correction coefficient; a second multiplier generating a corrected minimum value by multiplying the minimum value of the digital signals by the correction coefficient; and an output portion outputting the corrected maximum value or an absolute value of the corrected minimum value as the amplitude of the waveform signal.