Patent ID: 10840868

Abstract:
Systems and methods for measurement of signal power, when the signal is substantially variable or otherwise time varying. A log-linear VGA is coupled in a feedback configuration to a difference-of-squares detector and an integrator. The log-linear VGA includes a set of selectable amplifier cells. A sliding current generator selects one or more amplifier cells, wholly or partially, producing a sum of outputs. Some of the selectable amplifier cells have differential amplification, while others have similar amplification but are differentially attenuated. Switches turn off to isolate amplifier cells when the cell is not selected. Canceling circuits produce an output opposite to unselected amplifier cells, providing a sum near zero. Temperature compensation and other adjustment include two components: when the output y and the input x have the relation y=a+b log x the log-linear VGA can adjust either the offset or slope.