Stability of zeros of sampled system with fractional order hold

The paper deals with the stability of zeros of sampled-systems that are composed of a fractional-order hold, a continuous-time plant and a sampler in cascade. The stability conditions of the limiting zeros for sufficiently small or large sampling periods are derived. It is also shown that one can determine the range of the sampling period for stable zeros of the sampled system by calculating an analytical form of a criterion under a lowpass assumption on a continuous plant