A proposal of non-stationary low-pass Chebyshev´s filters

The analog low-pass filters with constant coefficients are often used for preliminary bounding of signals spectrum. The transient state of such filters depends on type and order of approximation, assumed filter accuracy /spl alpha/ as well as required bounding frequency /spl Omega/. There is contradiction between spectral and dynamic properties. A suitable choice of approximation allows to decrease, in part, the disadvantageous influence of transient state on quality of filtration. There is additional possibility of transient state shortening. Filter parameters can vary. The way of variation of parameters should guarantee assumed spectral properties after transient state. Results of the research work on averaging filters with variable parameters enable to foresee the way of variation of chosen parameters. Chebyshev´s filters with variable parameters have been examined. Dynamical properties of these filters have been compared to analogical filters with constant parameters.