Current closed-form IIR methods for approximating an analogue prototype filter in the discrete-domain do not match frequency response phase. The frequency sampling method can match phase, but requires extremely long filter lengths (and corresponding latency) to perform well at low frequencies. We propose a method for discretizing an analogue prototype that does not succumb to these issues. Contrary to the IIR methods, it accurately approximates the phase, as well as the magnitude response. The proposed method exhibits good low frequency resolution using much smaller filter lengths than design by frequency sampling.
Click to purchase paper as a non-member or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!
This paper costs $33 for non-members and is free for AES members and E-Library subscribers.