Adaptive Filtering of Blocker Signals in Demodulators

Abstract

Some embodiments of the invention relate a transimpedance amplifier circuit having a negative feedback network that provides additional filtering of an out-of-band transmitted signal is provided herein. In one embodiment, the transimpedance amplifier circuit has a first pole, transimpedance amplifier having a multi-stage operational amplifier with an input terminal and an output terminal. An RC feedback network extends from the output terminal to the input terminal. A negative feedback network, extending from an internal node of the multi-stage operational amplifier to an input terminal of the single pole, transimpedance amplifier provides a negative feedback signal with an amplitude having an opposite polarity as the out-of-band transmitted signal. The negative feedback signal suppresses the out-of-band-transmitted signals within the demodulator circuit, thereby improving linearity of the transimpedance amplifier circuit.

Dependencies are inferred from the claim text.