For 8.3a, is the low frequency asymptote just zero or is a constant times s? I am scratching my head on this one. The gain goes to zero as the frequency goes to zero so I can argue that zero is the asymptote (the value at zero) but the gain does not flatten out as is approaches zero. There is an asymptote at +20 dB/decade which is jsut a constant times s.
What are others thinking?
2 comments:
If I am right, I think the gain should 'approach' to zero as the frequency decreases and still depend on 's', like characteristics of a high pass filter. I assume that the figures are not very precise. like in section 8.1.4
I agree. The gain approaches zero as the frequency approaches zero. This can be seen from the expression for the slope of the asymptote. But this seems like more of an after-thought, rather than information that is needed to solve the problem. A good check I guess.
Also, I agree that the figures are not meant to be very thorough. They show enough information for what is needed in the problem.
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