Find the corner (−3 dB) frequency fc of the RC low-pass filter shown, with R = 10 kΩ, C = 100 nF. Give it in Hz.
Bode plots & margins worksheet with answers
Sketch the asymptotic Bode magnitude plot of G(s) = 500000/((s + 1000)(s + 10)). What is the slope n of the straight-line asymptote above 1000 rad/s, in dB/decade?
In the series RLC band-pass filter shown the output is taken across R = 10 Ω, with L = 1 mH and C = 0.1 µF. Find the −3 dB bandwidth BW in Hz.
The RC high-pass filter shown has R = 1 kΩ, C = 10 nF. A sinusoidal input of 3.2 kHz is applied. Find the gain |H| = |vout/vin| in dB.
A unity-feedback loop has the open-loop transfer function L(s) = 8/(s(s + 2)(s + 3)). Find the phase crossover frequency ω180, where ∠L(jω) = −180°.
A unity-feedback loop has the open-loop transfer function L(s) = 614/(s(s + 8)(s + 9)). Find the gain margin GM in dB.
Answer key
- 1. fc = 159.2 Hz
- 2. n = −40 dB/dec
- 3. BW = 1592 Hz
- 4. |H| = −14.11 dB
- 5. ω180 = 2.449 rad/s
- 6. GM = 5.992 dB
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