Properties of ROC of Laplace Transform:
1. The ROC of X(s) consists of strips parallel to the jω axis in the s-plane.
2. The ROC does not contain any poles.
3. If x(t) is of finite duration and is absolutely integrable, then the ROC is the entire s-plane.
4. It x(t) is a right sided signal, that is x(t) = 0 for t<t0<∞ then the ROC is of the form Re(s)> amax , where a max equals the maximum real part of any of the poles of X(s).
5. If x(t) is a left sided, that is x(t) = 0 for t>t1> -∞, then the ROC is of the form Re(s)< amin , where amin equals the minimum real part of any of the poles of X(s).
6. If x(t) is a two sided signal, than the ROC is of the form a1<Re(s)< a2.