Patent ID: 7206357

Claim:
A signal transmitter for sending a radio signal, the transmitter comprising: an input for receiving input data; a first circuit for generating an inphase signal and a quadrature signal from the input data; a second circuit that produces a first signal associated with a cosine of a first frequency; a third circuit that produces a second signal associated with a sine of the first frequency; a first modulator, coupled to the first circuit and the second circuit, that upconverts the inphase signal with the first signal and produces a first upconverted signal; a second modulator, coupled to the first circuit and the third circuit, that upconverts the inphase signal with the second signal and produces a second upconverted signal; a third modulator, coupled to the first circuit and the second circuit, that upconverts the quadrature signal with the first signal and produces a third upconverted signal; a fourth modulator, coupled to the first circuit and the third circuit, that upconverts the quadrature signal with the second signal and produces a fourth upconverted signal; a fourth circuit, coupled to the first and fourth modulators, that combines the first upconverted signal and the fourth upconverted signal into a first intermediate signal; a fifth circuit, coupled to the second and third modulators, that combines an inverse of the second upconverted signal and the third upconverted signal into a second intermediate signal; a quadrature modulator, coupled to the fourth circuit and the fifth circuit, that converts the first intermediate frequency signal and the second intermediate frequency signal to an output signal, the output signal having a component at a first sideband of a second frequency, the sideband frequency offset from the second frequency by a first amount; and a filter, coupled to the quadrature modulator, that passes the sideband frequency, and filters the second frequency and a second sideband, the second sideband offset from the second frequency by the inverse of the first amount.