A variable-gain superregenerative amplifier controlled by duty-cycle for signal conditioning

摘要

In this paper, a variable-gain amplifier (VGA) adjusted by the duty-cycle of a control signal is presented. This circuit is based on the superregenerative concept created by Armstrong back in the 1920s. The technique selected allows a fine control of the gain to be performed without any D/A converter at the interface between the digital control and the amplifier, as generally seen in other VGAs. An integrated-circuit version of the VGA was fabricated in a standard CMOS process, aimed at achieving low-power consumption. Simulation results show a maximum gain of within a linear range, THD and a power consumption of . Measurements on the chip were performed and the results corroborate the simulations.