Patent ID: 7657247

Claim:
A Gilbert cell mixer for a wireless transceiver, the Gilbert cell mixer comprising: a first stage that performs voltage to current conversion, and that includes first and second transistors that are operated in a saturation region and third and fourth transistors that are operated in a triode region based on a first bias voltage; a second stage that communicates with said first stage and that performs frequency conversion; and a biasing circuit that communicates with said first stage, and that maintains a constant input linear range over temperature and process variations, wherein at least one of: said first and second transistors are biased into said saturation region based on: said first bias voltage; and a second bias voltage of first and second biasing transistors, said first and second biasing transistors being connected in series with respective ones of said first and second transistors; and said third and fourth transistors are biased into said triode region based on: said first bias voltage; and a third bias voltage of third and fourth biasing transistors, said third and fourth biasing transistors being connected in series with respective ones of said third and fourth transistors.