I'm having trouble understanding the bode plot for,
\(G(s) = \frac{1}{2s-1}\)
Usually when I am drawing bode plots for either real poles or zeros, I simply solve for the break frequency knowing that a zero/pole will give me a +/-20dB/decade asymptote after the break frequency on my magnitude plot, and a +/-90° phase shift across two decades, with the center (i.e. the +/-45° point) at my break frequency on my phase plot.
This has always worked when I have,
\((s+a) \quad a>0\)
but it seems to change when,
\((s - a) \quad a>0 \quad \text{or, } \quad (-s+a) \quad a>0\)
I can't wrap my head around why a pole has an increasing phase that starts at -180°. I was expecting a phase decrease from 0° to -90°.
Can someone explain what I am misunderstanding?
\(G(s) = \frac{1}{2s-1}\)
Usually when I am drawing bode plots for either real poles or zeros, I simply solve for the break frequency knowing that a zero/pole will give me a +/-20dB/decade asymptote after the break frequency on my magnitude plot, and a +/-90° phase shift across two decades, with the center (i.e. the +/-45° point) at my break frequency on my phase plot.
This has always worked when I have,
\((s+a) \quad a>0\)
but it seems to change when,
\((s - a) \quad a>0 \quad \text{or, } \quad (-s+a) \quad a>0\)
I can't wrap my head around why a pole has an increasing phase that starts at -180°. I was expecting a phase decrease from 0° to -90°.
Can someone explain what I am misunderstanding?
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