Patent ID: 7139326

Claim:
An image-canceling quadrature modulator comprising: a first complex modulator responsive to a complex carrier signal, the complex carrier signal including a baseband signal and signal images for frequency shifting the baseband signal and signal images to generate frequency shifted baseband signal and signal images; a first filter responsive to the frequency shifted baseband signal and signal images from said first complex modulator to generate frequency shifted filtered baseband signal and signal images; a second complex modulator responsive to said complex carrier signal for phase and frequency shifting the baseband signal and signal images to generate phase and frequency shifted baseband signal and signal images; a second filter responsive to the phase and frequency shifted baseband signal and signal images from said second complex modulator to generate phase and frequency shifted filtered baseband signal and signal images; and a combiner circuit for combining the frequency shifted filtered baseband signal and signal images from said first filter with the phase and frequency shifted filtered baseband signal and signal images from said second filter for suppressing said signal images and isolating the frequency shifted baseband signal.