Reconfigurable mismatch-free time-interleaved bandpass sigma-delta modulator for wireless communications

A reconfigurable bandpass time-interleaved sigma-delta modulator to achieve a wide tuning range is presented. With the calculated control parameters, the interleaving mismatch tones can always be shifted out of the interesting band during the whole tuning range, allowing always a mismatch-free implementation. The proposed method adopts a look-up table to obtain the various parameters including path numbers, path sampling frequencies, and tuning coefficients. With higher levels of reconfigurability the design meets the requirements of a multiband receiver for software defined radio systems, and the technique verified by behavioural simulations that also confirm the performance.