- #1

- 12

- 0

## Main Question or Discussion Point

I have a question related to that is explained on the textbook Sedra & Smith.

for a pole at s=a+bj,say, 1/(s-a-bj) why can we have the time domain of the signal to

be exp(at+jbt)? It is strange because s=jw, so Re(s)=0 <a ,which leads to the solution to

be -exp(-at-bjt)u(-t), so that the laplace transform will be convergent.

Recall that inverse LT of 1/(s-a) is exp(-at)u(t) for Re(s)>a ,-exp(at)u(-t) for Re(s)<a

Could you explain it to me ? Thank you.

Best wishes,

WANG Lu, Mike

for a pole at s=a+bj,say, 1/(s-a-bj) why can we have the time domain of the signal to

be exp(at+jbt)? It is strange because s=jw, so Re(s)=0 <a ,which leads to the solution to

be -exp(-at-bjt)u(-t), so that the laplace transform will be convergent.

Recall that inverse LT of 1/(s-a) is exp(-at)u(t) for Re(s)>a ,-exp(at)u(-t) for Re(s)<a

Could you explain it to me ? Thank you.

Best wishes,

WANG Lu, Mike