ELEC 320, Fall 1998

Prof. Rich Kozick

Prof. Rich Kozick

- Please read Chapter 1 in the Kamen/Heck as follows:
read section 1.1, browse sections 1.2-1.4, and read section
1.5.
The key concepts are:
what is a signal,
what is a system, continuous-time versus discrete-time,
and what does it mean for a system to be
*linear*,*time-invariant*, and*causal*. - Please construct Bode plots for the magnitude and phase
response
for
the following circuit. On your magnitude plot, label the -3 dB cutoff
frequency, the gain of the filter in the passband, and the slope of
the "roll-off" in the stopband.
[CIRCUIT DIAGRAM OMITTED IN HTML VERSION]

- This exercise will provide practice converting between
amplitude gain and decibels (dB). Consider a sine wave with amplitude
1 volt that is passed through 7 filters. The filter gains at the sine
wave frequency are as follows:
0 dB, 3 dB, 6 dB -3 dB, 20 dB, -20 dB, and - 40 dB

What is the amplitude (in volts) of the output sine wave from each filter?

- Obtain Bode plots (magnitude and phase versus frequency) for the
following circuits.
What type of filter is each circuit?
What is the formula for the cutoff frequency
w
_{c}in terms of the values of R and C?

The frequency axis in your plots should span at least 4 orders of magnitude, including w_{c}/100, w_{c}/10, w_{c}, 10 w_{c}, and 100 w_{c}. Be sure to indicate the pass-band gain and the slope of the roll-off in the stop-band in your plots.[CIRCUIT DIAGRAM OMITTED IN HTML VERSION]

- Classify each of the following filters
as low-pass,
high-pass, or band-pass. You can do this by looking at each filter as
a voltage divider, and determining the behavior of each impedance in
the circuit for low frequencies, middle frequencies, and high
frequencies. Alternatively, you can write the equation for the
frequency response and study its behavior as the frequency varies.
[CIRCUIT DIAGRAM OMITTED IN HTML VERSION]

For the low-pass filters: Is one of them "closer" to an ideal filter than the others? Please explain.