Fractional order Chebyshev-like low-pass filters based on integer order poles

Chebyshev filter is one of the most commonly used prototype filters that approximate the ideal magnitude response. In this paper, a simple and fast approach to create fractional order Chebyshev-like filter using its integer order poles is discussed. The transfer functions for the fractional filters are developed using the integer order poles from the traditional filter. This approach makes this work the first to generate fractional order transfer functions knowing their poles. The magnitude, phase, step responses, and group delay are simulated for different fractional orders showing their Chebyshev-like characteristics while achieving a fractional order slope. Circuit simulations using Advanced Design Systems of active and passive realizations of the proposed filters are also included and compared with Matlab numerical simulations proving the reliability of the design procedure. Experimental results of a two-stage active realization show good accordance with ADS and Matlab results.