Bessel filters are in the category of maximally flat filters similar to Butterworth but have a critically damped time-domain response similar to a First-Order Cascade filter. Bessel filters have a linear phase response over the filter's passband, which makes them useful in audio applications. Figure P14=50 shows a fourth-order Bessel filter with a \(20-\mathrm{kHz}\) cutoff and a \(0-\mathrm{dB}\) passband gain. Design a fourth-order First-Order Cascade and a fourth-order Butterworth filter with the same cutoff frequency and gain. Compare the frequency and time responses of the three filters and comment on their strengths and weaknesses.

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