TABLE OF CONTENTS In the following problems, loss specifications are loosely meant to be in terms of relative loss unless otherwise specified. Flat loss is therefore ignored in most problem definitions.
8.1 Determine the order of a Butterworth polynomial so that the following requirements will be met. Also specify an appropriate frequency scale factor so the prototype design will meet the requirements. The requirements are that the passband should have less than 2-dB loss for all frequencies less than 3 kHz, and the stopband should have more than 30-dB loss for all frequencies greater than 9 kHz.
8.2 Find values for ? and n so that a Chebyshev filter will provide less than 1 dB of ripple in the passband and more than 70 dB of loss for all frequencies greater than 2.5 times the passband cutoff frequency.
8.3 A customer wants an active Chebyshev LP filter to provide relative losses of less than 1 dB for all frequencies less than 3 kHz and more than 66 dB for all frequencies greater than 9 kHz. Explain why you might try to get the stopband specification lowered by 1 or 2 dB.
8.4 An LP filter has the following requirements: the passband loss should be less than 1 dB for all frequencies less than 3 kHz, and the stopband loss should be greater than 60 dB for all frequencies greater than 5 kHz.
What minimum-order Butterworth function is required to meet the requirement? Find the poles, and specify a suitable...
