US Patent 8704597 Amplifiers and related receiver systems

Apparatus are provided for amplifier circuits and related receiver systems. An amplifier circuit includes a first common-source amplification stage and a second common-source amplification stage. The input of the second common-source amplification stage is coupled to the output of the first common-source amplification stage such that the first common-source amplification stage generates a first amplified signal, and the second common-source amplification stage generates a second amplified signal based on the first amplified signal. The first common-source amplification stage is coupled to a first node and the second common-source amplification stage is coupled to a second node, wherein the common-source amplification stages are configured such that a current between the first node and the second node flows in series through the common-source amplification stages.