- #1
NHLspl09
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Hi all, on a current homework I have been given a transfer function and asked to draw the straight-line (asymptotic) magnitude (dB) and phase (degrees) Bode plot. I first learned Bode plots roughly a year ago, and while being on spring break and my notebook from last year is at school, I'm having difficulty remembering some techniques. I do know how to plot these when given a zero frequency, but in this specific problem, this transfer function has no zeros and has three poles. Judging from my notes from this class, I tried my best to dictate what to do for the magnitude, but was posting here to check and make sure I plotted the magnitude properly. My handwork to show the breakpoints and slopes is in Attachment 2 - Handwork, and the magnitude plot can be seen through Attachment 3 - Magnitude Plot.
My question though is for the phase plot. As seen in my handwork, I think that because the numerator is second order, it's slope should be +90°/decade, but am I supposed to include that in the phase plot because there is no zero frequency? Also, I'm a little fuzzy as to how I find out where I begin my plot in degrees - I have been taught that you begin with a slope of 0°/decade and end with a slope of 0°/decade, but how do I know where to begin my plot for phase?
Any help on this topic would be greatly appreciated!
(Attachment 1 - Problem)
None.
(Attachment 2 - Handwork)
(Attachment 3 - Magnitude Plot)
My question though is for the phase plot. As seen in my handwork, I think that because the numerator is second order, it's slope should be +90°/decade, but am I supposed to include that in the phase plot because there is no zero frequency? Also, I'm a little fuzzy as to how I find out where I begin my plot in degrees - I have been taught that you begin with a slope of 0°/decade and end with a slope of 0°/decade, but how do I know where to begin my plot for phase?
Any help on this topic would be greatly appreciated!
Homework Statement
(Attachment 1 - Problem)
Homework Equations
None.
The Attempt at a Solution
(Attachment 2 - Handwork)
(Attachment 3 - Magnitude Plot)