Design of narrow transition band variable bandwidth digital filter
Subhabrata Roy, Abhijit Chandra · IET Circuits Devices & Systems · 2020
This study presents a novel implementation technique for linear phase variable bandwidth finite impulse response (FIR) filters with a noticeable reduction in transition bandwidth as well as hardware complexity. In this proposition, concept of Farrow structure based design technique is effectively utilised; whereas the fixed sub‐filters are constructed from a generalised interpolated bandpass method based low‐pass FIR filter by means of different techniques such as interpolation, up‐sampling and masking. Simulation results have shown the frequency response characteristics of several variable bandwidth FIR filters, designed with the help of the proposed architecture. Simulation results have shown a drastic reduction of transition bandwidth resulting from the proposed variable bandwidth FIR filters of up to ∼70–80%, when compared with other state‐of‐the‐art filtering techniques, with a significant reduction in hardware complexity of up to ∼50%.