Question

In a bode magnitude plot, which one of the following slopes would be exhibited at high frequencies by a 4th order all-pole system?

• A. -80 dB/decade
• B. -40 dB/decade
• C. 40 dB/decade
• D. 80 dB/decade

Hint:

In a Bode magnitude plot, the slope at high frequencies for an all-pole system is determined by the number of poles, with each pole contributing -20 dB/decade.

Answer 1

The Correct Option is A

For a 4th order all-pole system, the high-frequency asymptote of the Bode magnitude plot typically has a slope of -80 dB/decade. This is because each pole contributes -20 dB/decade to the slope, and for a 4th order system, the total slope at high frequencies is \(4 \times (-20 \, \text{dB/decade}) = -80 \, \text{dB/decade}\). Thus, the correct answer is -80 dB/decade.