Is it true to say that all non causal systems are unrealizable?

Is it true to say that all non causal systems are unrealizable?

No, all non causal systems are not unrealizable. For a finite non-causality we can delay the system response. Also in case of infinitely non-causal systems if some amount of error is allowed by the system then the previous approach for finite non-causal system can be used.

What is improper transfer function?

Explanation : Improper Transfer Function measures that the order of numerator must be greater than that of denominator, while proper transfer function measures that the degree of numerator should not exceed than the degree of denominator.

Can a transfer function be improper?

If a transfer function is improper, then that system cannot be causal and stable at the same time.

How do you know if a transfer function is correct?

A transfer function is said to be proper if its relative degree is greater than or equal to zero, and strictly proper if the relative degree is greater than or equal to one.

How are causality and stability related in improper systems?

So how are causality and stability related in improper systems? An improper system cannot be causal and stable. If the order of the numerator is greater than the order of the denominator, you’ll always have at least one pole at infinity.

Can a causal system have a stable transfer function?

For discrete-time systems the same is true. A transfer function for which the degree of the numerator is greater than the degree of the denominator has at least one pole at infinity. Since causal and stable discrete-time systems must have all their poles inside the unit circle, such a system can’t be causal and stable.

What happens if a transfer function is improper?

This answer and the comments in it made me wonder whether the following statement is true: If a transfer function is improper, then that system cannot be causal and stable at the same time. I had thought that this was true for a while.