Patent ID: 7375577

Claim:
A mixer, comprising: a mixing module for mixing a first set of differential signals and a second set of differential signals to generate a mixed signal, comprising: a plurality of switching transistors for mixing the first set of differential signals and the second set of differential signals to generate a set of differential current signals; and a current-to-voltage converter coupled to the switching transistors for generating the mixed signal according to the set of differential current signals; a common mode voltage generator coupled to the mixing module for generating a common mode voltage according the set of differential current signals; and a compensation module coupled to the common mode voltage generator and the mixing module for compensating at least one operation point of the mixing module according to the common mode voltage, comprising: a biasing circuit for generating a biasing voltage; a voltage synthesizing circuit coupled to the biasing circuit for generating a synthesized voltage according to the common mode voltage and the biasing voltage; and a plurality of biasing units respectively coupled to the switching transistors and the voltage synthesizing circuit for compensating operation points of the switching transistors according to the synthesized voltage.