Stability-guaranteed minimax design of variable bandpass digital filter
Tian–Bo Deng · 2017
This paper presents a minimax design algorithm for designing a recursive variable band-pass filter (VBPF) with ensured stability. The algorithm first individually designs a set of constant band-pass filter (CBPF) through minimizing the maximum absolute magnitude-response error, which is called minimax design. Then, each VBPF coefficient is represented as a polynomial in the bandedge-tuning parameter. This enables the filter users to change the VBPF coefficients and thus yield a VBPF with variable band-edge frequencies. Moreover, we adopt the denominator-coefficient-transformation scheme and apply a new transformation function for ensuring the stability of the designed VBPF. An example is given to illustrate the approximation errors and stability issue of the minimax design methodology.