Impulse response of an infinite-length system

1. What is meant by infinite impulse response?
2. Why is the impulse response infinite?
3. What is impulse response length?
4. How do you find the impulse response of a linear system?

What is meant by infinite impulse response?

Infinite impulse response (IIR) is a property applying to many linear time-invariant systems that are distinguished by having an impulse response which does not become exactly zero past a certain point, but continues indefinitely.

Why is the impulse response infinite?

Infinite impulse response (IIR) filters are based on analog filters, where the frequency response is defined by both poles and zeros. Finite impulse response filters, in contrast, only have zeros. The presence of poles in the IIR filter causes the impulse response to be infinitely long.

What is impulse response length?

Length of the impulse response, specified as a positive integer. For stable IIR filters with absolutely summable impulse responses, impzlength returns an effective length for the impulse response beyond which the coefficients are essentially zero.

How do you find the impulse response of a linear system?

The impulse response for an LTI system is the output, y ( t ) y(t) y(t), when the input is the unit impulse signal, σ ( t ) \sigma(t) σ(t). In other words, when x ( t ) = σ ( t ) , h ( t ) = y ( t ) .