A fractional-order IMC controller for high-order Sigma-Delta modulator

A fractional-order internal model control (IMC) is proposed for high-order Sigma-Delta (ΣΔ) modulator in the paper. Designing a high-order ΣΔ modulator is difficult due to the complex parameters' tuning and system instability. IMC is used to effectively reduce the tuning parameters and also improve the system robustness of ΣΔ modulator with respect to model-plant mismatch and system noises. Additionally, the tuning parameters are optimized by PSO, which is more convenient to achieve the parameters. The simulation results show that the proposed IMC is useful for improving the performance for high-order ΣΔ modulator.