Extended Noise Shaping in Sigma-Delta Modulator Using Cross-Coupled Paths

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

“…By this way, when changing the path numbers, only the coupling coefficients' matrices need to be changed for tuning the centre frequency, while the remaining integrators as well as the delay blocks, can be reused. Table 2 for the demonstration, because they already cover the whole UHF band to ensure mismatch-free operation under (2). With a 4-bit quantiser working in each path, the testing model was built and evaluated using MATLAB with SIMULINK.…”

“…In this Letter, the proposed method simply utilises the reconfigurable feature of the time-interleaved SDM to avoid the collision between the mismatch tones and the signal band. Regarding the tuning, without changing the analogue blocks of the main path, the desired noise shaping can be attained by modifying the coupling matrix [2]. For further precise control, a look-up table governs the programmable parameters.…”

Dual Extended Noise Shaping for High Performance Cross-Coupled Sigma-Delta Modulators

“…This is used to obtain the output at , thereby, reduces the noise power of each path by . Therefore, the total noise power of the uncorrelated noise terms equals the noise power of a single path [6]. The quantization error (Ɛ) is computed by subtracting the input of ADC from the output of the DAC for each path.…”

“…The The coupling matrix [ ] × is different from the matrix mentioned for unextended and extended architecture proposed in [6]. As the quantization errors of each path is not cross-coupled to itself, the diagonal element of [ ] × and [ ′] × are equal to zero.…”

“…In addition, the effect of cross-coupling the noise on time-interleaved sigma-delta ADCs is investigated in [5]. Hamidi et al proposed an unextended and extended noise-coupling techniques in TI crosscoupled ΣΔ modulators to improve the effective order to (2 − 1) [6].…”