Quantization error analysis of second order bandpass Delta-Sigma modulatorwith sinusoidal inputs

The exact analysis of second order bandpass Delta-Sigma modulator with sinu soidal inputs is performed. The results indicate that quantization error is neither uniformly distributed nor white. The quantization error spectrum i s purely discrete and symmetric with one forth of sampling frequency, and t he locations of these discrete frequency components are strongly dependent on input amplitudes. Similar results are also observed for passband communi cation signals, such as quadrature amplitude modulation. From the analysis, crosscorrelation between quantization error and sinusoidal input was shown to exist but can be cancelled out by proper design of the noise shaping fu nction. Crosscorrelation can degrade the performance of the delta-sigma sys tem. Hence, the exact analysis is another method to enable design for high performance.