Mismatch cancellation in quadrature bandpass delta-sigma modulators using an error shaping technique

Techniques for shaping component mismatch error in the real and imaginary paths of a complex (quadrature) delta-sigma are studied, simulated and compared to existing techniques. Complex bandpass delta-sigma modulators provide improved performance over a pair of real bandpass delta-sigma modulators of the same order in the conversion of narrow-band quadrature IF (intermediate frequency) signals. This is possible due to elimination of redundant conjugate pairs of poles and zeros in its noise and signal transfer function. Mismatches in the modulators real and imaginary paths, however, results in spectral leakage of image band interference and image band quantization noise to the passband of the converted output. Strategic pole-zero placement, as well as adaptive techniques have been studied in earlier works. This thesis will take advantage of the inherent dual paths of the complex bandpass delta-sigma modulator to reduce component mismatch effects using a switched capacitor error shaping technique.