LINEARITY IMPROVEMENT OF GILBERT MIXERS

摘要

Method and system are disclosed for providing an improved linearity Gilbert mixer. The Gilbert mixer of the ivention includes a convenional mixer core coupled to a high linearity multiusage amplifier. The multiusage amplier includes two or more transistor stage connected together in a global arragement. The global feedback provides a greater loop gain for the amplifier that the local fedback arragement, thereby increasing the linearity of the amplier. In addition, having more than one transistor stage in the amplifier serves to increase the isolation of the RF input signal from the LO input signal. Furthermore, by providing parallel output stages in the multistage amplifier, several mixer cores may be driven from the source while sharing the feedback mechanism.