ELEC 320, Fall 1998
Prof. Rich Kozick

Homework 15

Date Assigned: Monday, October 19, 1998
Date Due: Friday, October 23, 1998 ** CHANGED TO MONDAY, OCTOBER 26, 1998 **

  1. Please solve Problem 4.2 for the signal shown in Figure P4.2(e). Use MATLAB for part (iii). The example MATLAB program that we showed in class for plotting a truncated Fourier series is available at

  2. Please solve problem 4.6. Note that the "overbar" on the function refers to complex conjugate. The complex conjugate of exp(j w t) is exp(-j w t).

  3. Suppose that the square wave x(t) shown on page 3 of the class notes is applied to a low-pass RC circuit with RC = 1 and frequency response H(w) = 1 / (1 + j w). Obtain an expression for the Fourier series of the output signal y(t).

    (Hint: Use linearity and the definition of frequency response!)

    Try running the MATLAB program sqrfilt.m (available on the Web page for this assignment) to see a plot of the output y(t). Can you relate the fact that y(t) is nearly a triangle wave to the results that you obtained in item 1 of this assignment? (Do your best on this -- the connection may not be obvious!)

Thank you.