ELEC 320, Fall 2006
Prof. Rich Kozick

## Homework 11

Date Assigned: Friday, November 3, 2006
Date Due: Friday, November 10, 2006

1. Reading: Please continue to study Chapter 3 in the Lathi text on Fourier series, Sections 3.5-3.9. For our classes on November 10 and the week of November 13, please begin studying Chapter 4 in the Lathi text on the Fourier transform, Sections 4.1 and 4.2.

2. Exam 3 will be on Friday, November 17. (This date was tentatively listed on the course syllabus, but it is now confirmed.)

3. Please solve the following problems in Chapter 3 of the Lathi text.
Problems 3.5-1 (parts d and e only), 3.5-2, 3.5-3.
Note: The answer in the back of the book for Problem 3.5-1(e) is incorrect. The Dn formula must be multiplied by (1/2) to make it correct.

4. Develop a Matlab program to plot the time signals using the truncated exponential Fourier series using your results from problems 3.5-1 (parts d and e).

The program fstrun_exp.m that we used in class may be a useful template for your program.

5. Suppose that the signal f(t) in Figure P3.4-3(e) in the Lathi text is applied to a low-pass RC circuit with RC = 0.5 and frequency response H(w) = 1 / (1 + j (w/2)).
• Find an expression for the exponential Fourier series of the output signal, y(t). Use your result from Problem 3.5-1(e) and the frequency response, H(w).
• Develop a Matlab program to plot y(t) using a truncated exponential Fourier series. You may want to refer to the Matlab program sqrfilt.m that we used in class to find the output of a low-pass RC circuit with frequency response
H(w) = 1 / (1 + j (w/wc)) to a square wave. This program uses the compact trigonometric Fourier series.

6. Please solve the following problem in the Lathi text.
Problem 3.5-5 (review Parseval's Theorem in Section 3.5-2).

Thank you.