EE 432/632 LABORATORY I A
Frequency and Step Responses of First-Order Passive Filters
Prelab: 1. Design a passive first-order RC low-pass filter with cutoff frequency fH = 10 kHz. Derive the step response, voltage transfer function, and sketch Bode plots (magnitude and phase). 2. Design a passive first-order RC high-pass filter with cutoff frequency fi = 1 kHz. Derive the step response, voltage transfer function, and sketch Bode plots (magnitude and phase).
Experiments: 1. Build and test the low-pass filter designed in part 1 of the Prelab. a) Using a sine-wave input voltage of magnitude 1 V, measure fH of the filter. b) Keeping the input voltage magnitude constant, measure the output magnitude and time shift of the output waveform at several different frequencies (i.e. 100 Hz, 500 Hz, 1 kHz, ... ,1 MHz). Use this data to generate Bode plots of Az, and phase. c) Apply a square-wave input voltage of magnitude 1 V withf = 0.1 fH. Sketch the step response of the filter and measure the time constant T. 2. Repeat Experiment 1 for the high-pass filter designed in part 2 of the Prelab.
Postlab: Submit a written report. 1. Compare the measured and theoretical values of fH, fL, and T. 2. Use Excel or MATLAB to plot the data measured in Step 1(b). Compare these plots with the theoretical Bode plots from the Prelab. 3. Compare the observed step response with the theoretical response.
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Figure 1(a): Low-pass filter. Figure 1(b): High-pass filter.
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