Single Bit All Digital Frequency Synthesis Using Homodyne Sigma Delta Modulation
All digital frequency synthesis using bandpass sigma delta modulation to achieve spectrally clean single bit output is presented and mathematically analyzed resulting in a complete model to predict the stability and output spectrum. The quadrature homodyne filter architecture is introduced resulting in efficient implementations of carrier frequency centered bandpass filters for the modulator. A multiplierless version of the quadrature homodyne filter architecture is also introduced to reduce complexity while maintaining a clean in band spectrum. MATLAB and SIMULINK simulation results present the potential capabilities of the synthesizer architectures and validate the accuracy of the developed theoretical framework.
IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control