A Quadrature Modulation Transmitter Using Two Frequency Synthesizers

This brief analyzes a novel quadrature modulation transmitter architecture. The proposed architecture consists of only two frequency synthesizers, thereby reducing the RF and analog components such as RF mixer, analog filter, and digital-to-analog converter. Simulation results show that the bit-error rate and the spectral efficiency of the proposed method are close to those of conventional quadrature modulation scheme. The quadrature modulation transmitter can be implemented fully digitally through the proposed architecture if the all-digital frequency synthesizer is used.