i am third year Electrical engineering student, i have some issues that i could not find a good explanation for it. lets say we have an RC circuit (low pass configuration). if we calculate the transfer function we get Vo/vi=1/1+RCS. so we have a single pole in s=-1/RC. my question is what will happened to transfer function we stimulate the system in frequency that is equal to the system pole. i would expect it to blow since the denominator is zero in this case, but if we look at the frequency of this system it never blow. so what am i missing here? is it possible at all to stimulate the system in it pole frequency? thanks!
If your stimulus is a sinewave at the corner frequency, you will see an output sinewave that's 3db lower than the input.
The transfer function doesn't "blow up" because you're not causing the denominator to become zero. You're looking at the special case where s=jw, (i.e. a pure sine on the jw axis) and w is the corner frequency.
Plug that (s=jw) into the transfer function and take the magnitude and you'll see that the output is just a sinewave with the 3dB attenuation.