The disclosed filter structure employs parallel first and second input signal data paths. The first data path includes a digital Finite Impulse Response (FIR) filter having a small number of non-zero multiplier coefficients to define its theoretical impulse frequency response. The second data path includes plural series filters including (1) a digital FIR or Infinite Impulse Response (IIR) filter including a reduced-number of designer-chosen non-zero multiplier coefficients that tend to introduce error sources in the physical-realized filter structure's impulse frequency response and (2) a set of one or more frequency stop filters, each of which permits zero signal transmission therethrough at a different selected frequency. This arrangement anchors the frequency response value of the filter structure near each of the different selected frequencies of the set substantially at the corresponding theoretical impulse frequency response value of the digital FIR filter of the first data path near that one of the plurality of different selected frequencies of the set. The summed outputs of the first and second data paths is the filter output.
