基于高阶Sigma-Delta调制器的PD~α相位补偿器设计

A design method of PD~α phase compensator for high-order sigma-delta modulator

针对高阶Sigma-Delta调制器稳定性差这一现实问题,提出分数阶PD~α相位补偿器的设计方法,能够有效弥补由于高阶Sigma-Delta调制器中多个积分器极点带来的系统相位滞后,提高系统稳定性,同时能够避免削弱系统输入信号增益,进一步提高了Sigma-Delta调制器噪声整形能力。采用粒子群优化算法设计所提分数阶PD~α相位补偿器参数,有效减小了所提新型相位补偿器的设计难度。最后,仿真结果验证了方法的可行性和实用性。

With respect to the unsatisfied stability of high-order Sigma-Delta modulator,a novel fractional-order PD~αphase compensator is proposed,which can make up for the phase lag caused by the integrators to improve the overall system stability of high-order Sigma-Delta modulator.Also,the proposed PD~αphase compensator can avoid to weaken the gain of input signal and further improve the noise-shaping ability.In order to simplify the complexity in parameters’tuning,particle swarm optimization(PSO)algorithm is employed to design the parameters for PD~αphase compensator.Finally,the simulation results conform the feasibility and practicability of the proposed method.