Howtosignalprocessing
- Why is ideal filter impossible?
- What is the disadvantage of digital filter?
- Why is digital filter better than analog?
- How do I know if my digital filter is stable?
Why is ideal filter impossible?
The reason is that their frequency responses include exactly flat passbands, exactly flat stopbands of zero gain, and zero width transition bands. These features make it impossible to realize such filters using either existing physical devices or finite-time computable algorithms...
What is the disadvantage of digital filter?
The standard disadvantage of a digital filter is that digital filters are significantly slower than analog filters (Smith). Digital filters introduce additional latency into a system, as the analog data that comes out of the hardware must be processed on a computer before it is filtered as desired.
Why is digital filter better than analog?
Digital filters require only the arithmetic operations of addition, subtraction, and multiplication. Digital filters do not drift with temperature or humidity or require precision components. Digital filters have a superior performance-to-cost ratio. Digital filters do not suffer from manufacturing variations or aging.
How do I know if my digital filter is stable?
A digital filter is stable if and only if all the poles of the irreducible filter transfer function lie inside the unit circle in the z plane. Any pole outside the unit circle introduces an exponentially increasing component in the filter's impulse response, thus causing the filter to be unstable.
