| 摘要 |
A logarithmic amplifier is configured to produce a logarithmic output signal that is an logarithmic function of an input signal. The amplifier comprises a reference signal, first and second function generators, and a low-pass filter. The first function generator is configured to produce a periodic exponential waveform from the reference signal based upon a resistor-capacitor time constant, wherein the exponential waveform exponentially increases from a minimum value to a maximum value in each period. The second function generator is configured to produce a pulsed waveform from the exponential waveform, wherein the pulsed waveform has a signal period, and wherein the pulsed waveform comprises a first portion having a first amplitude for a first time period and a second portion having a different amplitude for the remainder of the signal period, and wherein the duration of the first time period is determined in response to the exponential waveform. The low pass filter is configured to produce the logarithmic output signal as a function of the pulsed waveform.
|
