Patent ID: 8493127

Claim:
A mixer, comprising: a Gilbert cell comprising: a transconductance stage having a differential baseband input and differential baseband output, the differential baseband output having a positive polarity and a negative polarity; and a mixer stage configured to modulate a signal present at the differential baseband output; a linearization circuit comprising: an operational amplifier having an output terminal, a positive input terminal, and a negative input terminal, and configured to receive a common-mode bias voltage at the negative input terminal; a first pass device having a gate terminal, a first non-gate terminal, and a second non-gate terminal and coupled to its gate terminal to the output terminal of the operational amplifier and configured to be coupled at its first non-gate terminal to a high potential source; a second pass device having a gate terminal, a first non-gate terminal, and a second non-gate terminal and coupled to its gate terminal to the output terminal of the operational amplifier and configured to be coupled at its first non-gate terminal to the high potential source; a first feedback resistor having a first terminal and a second terminal, the first terminal coupled to the positive input terminal of the operational amplifier and the second terminal coupled to the second non-gate terminal of the first pass device and the positive polarity of the differential baseband output; and a second feedback resistor having a first terminal and a second terminal, the first terminal coupled to the positive input terminal of the operational amplifier and the second terminal coupled to the second non-gate terminal of the second pass device and the negative polarity of the differential baseband output.