A linear time invariant system is characterized by the system function...
Explanation: The system has poles at z=0.5 and at z=3.
Since the system is causal, its ROC is |z|>0.5 and |z|>3. The common region is |z|>3. So, ROC of given H(z) is |z|>3.
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A linear time invariant system is characterized by the system function...
> |0.5|< />< />
To determine the ROC (region of convergence) of H(z), we need to find the values of z for which the series representation of H(z) converges. One approach is to use partial fraction decomposition to express H(z) as a sum of simpler terms with known ROCs.
H(z) can be written as:
H(z) = A/(1-0.5z-1) + B/(1-3z-1)
where A=1/2 and B=1. We can then use the formula for the ROC of a geometric series:
|z|>|a|
where a is the coefficient of the z term in the denominator, to find the ROC for each term.
For the first term, we have a=0.5, so the ROC is:
|z|>|0.5|
which is equivalent to:
|z|<|0.5| or="" |z|="">|0.5|
But since the system is causal, we know that the ROC cannot include any poles (zeros of the denominator). The poles of H(z) are at z=2 and z=1/3, so the ROC cannot include these values.
The second term has a=3, so the ROC is:
|z|>|3|
which is equivalent to:
|z|<|3| or="" |z|="">|3|
Again, since the system is causal, the ROC cannot include any poles.
Therefore, the only valid ROC for H(z) that satisfies the causal condition is:
|0.5|< /><|3|>|3|>|3|>|0.5|>