Patent ID: 7609779

Claim:
An integrated circuit configured to perform IQ modulation by interleaving in-phase and quadrature signals, the integrated circuit comprising: a baseband in-phase stage that receives an in-phase analog input signal; a baseband quadrature stage that receives a quadrature analog input signal; and a switching mixer having a first plurality of switches and a second plurality of switches, and the switching mixer receiving in-phase and quadrature signals from the baseband in-phase stage and the baseband quadrature stage, wherein each switch of the first plurality of switches is configured to apply a different one of a first, a second, a third, and a fourth phase of a plurality of phases a carrier period to a different one of a direct in-phase signal, an inverted in-phase signal, a direct quadrature signal, and an inverted quadrature signal derived from the in-phase and quadrature signals, and wherein the switching mixer is configured to combine resulting first up-converted signals to produce a first, interleaved differential signal component, and wherein each switch of the second plurality of switches is configured to apply the different one of the first, the second, the third, and the fourth phase to another different one of the direct in-phase signal, the inverted in-phase signal, the direct quadrature signal, and the inverted quadrature signal, and wherein the switching mixer is configured to combine resulting second up-converted signals to produce a second differential signal component, wherein the first differential signal component and the second differential signal component are produced as a differential output signal from the switching mixer, and wherein the differential output signal communicates a first direct and a first inverted in-phase signal during the first phase, a first direct and a first inverted quadrature signal during the second phase, a second direct and a second inverted in-phase signal during the third phase, and a second direct and a second inverted quadrature signal during the fourth phase.