Single-Bit All Digital Frequency Synthesis Using Homodyne Sigma-Delta Modulation.

All-digital frequency synthesis using band-pass sigma-delta modulation to achieve spectrally clean single-bit output is presented and mathematically analyzed resulting in a complete model to predict stability and output spectrum. The quadrature homodyne filter architecture is introduced resulting in efficient implementations of carrier-frequency centred bandpass filters for the modulator. A multiplier-less version of the quadrature homodyne filter architecture is also introduced to reduce complexity maintaining 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.