Patent ID: 7545197

Claim:
An anti-logarithmic amplifier configured to produce an anti-logarithmic output signal that is an anti-logarithmic function of an input signal, the anti-logarithmic amplifier comprising: a first function generator configured to produce a periodic exponential waveform based upon a resistor-capacitor time constant, the periodic exponential waveform having a period and a magnitude, wherein the magnitude of the periodic exponential waveform exponentially increases from a minimum value to a maximum value in each period; a second function generator configured to produce a ramp waveform from the periodic exponential waveform, wherein the ramp waveform has a ramp signal period substantially equal to the period of the periodic exponential waveform and a ramp magnitude substantially equal to the magnitude of the periodic exponential waveform at an end of the ramp signal period; a third function generator configured to produce a hybrid waveform in response to the ramp waveform, the hybrid waveform having a signal period, and wherein the hybrid waveform comprises a first portion having a first waveform for a first time period and a second portion having a second waveform different from the first waveform for a remainder of the signal period, and wherein a duration of the first time period is determined in response to the ramp waveform; and a low pass filter configured to receive the hybrid waveform and to produce the anti-logarithmic output signal as a function of the hybrid waveform.