Properties of zeros of a discrete-time system with fractional order hold

This paper is concerned with the properties of zeros of discrete-time systems which are composed of a hold, a continuous-time plant and a sampler in cascade. Here the fractional order hold is applied as the hold. The properties of the zeros are explored in the limiting cases when the sampling period tends to zero or infinity. The stability conditions of the zeros for sufficiently small or large sampling periods are also presented. A simulation example is shown to compare the fractional order hold with the zero-order hold