Patent ID: 8781026
Filing Date: 2014-07-15
Classification: H03C

Abstract:
1. A method used in a digital quadrature transmitter, comprising: generating a plurality of pairs of in-phase and quadrature modulated signal samples to be successively applied to a radio frequency digital-to-analog converter (RFDAC) for upconversion; selecting a phase of a local oscillator signal according to a quadrant determined by signs of a given pair of in-phase and quadrature modulated signal samples; supplying the selected phase of the local oscillator signal to the radio frequency digital-to-analog converter (RFDAC) for use in upconverting the in-phase and quadrature modulated signal samples; translating the in-phase and quadrature modulated signal samples to thermometer coded outputs that are supplied to inputs of the RFDAC to select transistors to be turned on in the RFDAC; and time-dithering the in-phase and quadrature modulated signal samples to produce resolution-increased versions of the in-phase and quadrature modulated signal samples.