ELEC 320, Fall 2004
Prof. Rich Kozick
Date Assigned: Friday,
November 12, 2004
Date Due: Wednesday,
November 17, 2004
- Exam 3 will be on Friday, November 19, 2004.
- Reading: Please continue
to study Chapter 4 in the Lathi text on the
Fourier transform. For next
week, please study Section 5.1 on the sampling theorem. You may also want to browse
sections 5.2 and 5.3 on the DFT and FFT (we discussed these in lab last
- Lab: Remember that your answers to
are due by Tuesday, November 16. Also, please continue to work on your lab
- The signal transmitted in
an ultrasound imaging system is typically a "sine wave burst" of
the form . This is a 1 MHz cosine that is "on" for T
(a) For T=10-6 sec, sketch x(t),
then find and plot .
(b) Repeat part (a) for T=10-5.
(c) Which case of signal would you call "narrowband", and which
is "wideband"? Look
at the signal bandwidth relative to the center frequency, 1 MHz. Can you
see why these names describe the "bandwidth" of the signal?
You may want to use MATLAB to produce the plots.
- Please solve the following
problems in the Lathi text:
Problems 4.3-7(a), 4.4-3, 4.6-2, 4.7-1 (a and b), and 4.7-3.
- Suppose we model a
telephone channel as an ideal low-pass filter with cutoff frequency 4000
Hz, with frequency response .
(a) What is the impulse response, h(t), of
this filter? Write the formula
for h(t), and sketch h(t). Is this a causal
(b) What is the filter output, y(t),
when the input is ? Sketch x(t) and
Extra credit: What is the filter output y(t)
when the input is a rectangular pulse, ?