# Lecture 5 Blog, ECE438 Fall 2011, Prof. Boutin

Wednesday August 31, 2011 (Week 2) - See Course Outline.

In the fifth lecture, we continued talking about the z-transform. We noted that there are signals for which the z-transform exists but the Fourier transform does not. We introduced the notion of "region of absolute converge" (ROC) for the z-transform and observed the fact that it consists of circles around the origin of the complex plane.

The homework was collected. Apparently, few people have the correct answers. I thus urge you to work on the following collective problem:

- Obtain the Fourier transform in terms of f of a step function (from FT in terms of omega)
- What is the Fourier transform of a complex exponential?

I have also created a practice problem for those of you who are not comfortable writing equations on Rhea.

Relevant Rhea pages:

Action items:

- Solve the following practice problem
- Begin working on the second homework. It is due next Wednesday (in class).

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