Patent ID: 7167686

Claim:
A wireless communications transmitter circuit comprising: a local oscillator for producing a signal at a multiple of an intermediate frequency; a quadrature modulator harmonic rejection mixer responsive to the signal at the multiple of the intermediate frequency for modulating an in-phase base-band signal and a quadrature-phase base-band signal to produce an intermediate frequency signal, wherein the quadrature modulator harmonic rejection mixer includes: a first circuit for generating multiple phases of a digital signal at the intermediate frequency responsive to the multiple of the intermediate frequency, wherein the multiple phases of the digital signal at the intermediate frequency includes a first set of at least two respective phases out of phase by ninety degrees relative to a second set of at least two respective phases; a second circuit for combining the in-phase base-band signal and the first set of at least two respective phases of the digital signal at the intermediate frequency responsive to a first set of at least two respective current sink weightings to produce a first set of at least two respective intermediate frequency output signals; a third circuit for combining the quadrature-phase baseband signal and the second set of at least two respective phases of the digital signal at the intermediate frequency responsive to a second set of at least two respective current sink weightings to produce a second set of at least two respective intermediate frequency output signals; and a fourth circuit for combining the first set of at least two respective intermediate frequency output signals and the second set of at least two respective intermediate frequency output signals to produce the intermediate frequency signal; a filter responsive to the intermediate frequency signal for producing a filtered intermediate frequency signal; and an RF output offset phase-locked loop responsive to the filtered intermediate frequency signal and responsive to the signal at the multiple of the intermediate frequency for producing an RF transmission signal; wherein the local oscillator produces a frequency equal to a frequency of the RF transmission signal multiplied by said multiple and divided by a sum of one plus the multiple.