AdvancedA-002-012-004
What are the distinguishing features of a Chebyshev filter?
C
Answer
Circuit design and power supplies
Type
A
It requires only inductors
B
It has a maximally flat response in the passband
C
It allows ripple in the passband in return for steeper skirts
D
It requires only capacitors
Answer Notes
The Chebyshev filter is mathematically designed to have a very steep roll-off, meaning the transition from the allowed frequencies (passband) to the rejected frequencies (stopband) is very sharp. This rapid transition is often described as having "steeper skirts."
However, this sharp frequency cutoff comes with an engineering trade-off. The Chebyshev filter introduces amplitude variations, commonly called "ripple," within the passband. This means the signal strength fluctuates slightly across the desired frequencies before being passed on to the rest of the circuit.
The incorrect option regarding a "maximally flat response in the passband" actually describes a Butterworth filter, which completely avoids passband ripple but sacrifices the steep roll-off. Additionally, Chebyshev filters require a carefully calculated network of both inductors and capacitors, making the options suggesting they use only one or the other incorrect.
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Which filter type is described as having ripple in the passband and a sharp cutoff?
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