In electrical engineering and control theory, a Bode plot is a graph of the frequency response of a system. It is usually a combination of a Bode magnitude plot, expressing the magnitude (usually in decibels) of the frequency response, and a Bode phase plot, expressing the phase shift.
As originally conceived by Hendrik Wade Bode in the 1930s, the plot is an asymptotic approximation of the frequency response, using straight line segments.
From 0 to ##10^3## ##\omega## there is a dB gain, from ##10^3## to ##10^5## there is another. Finally from ##10^5## to infinity the slope is constant (0).
I know the formula
$$dbV= 20log_{10}\frac{V_2}{V_1}$$
can give me the slope but that is in terms of Volts, but I have frequency and the...
Using analog discovery 2 kit and the bode plot produced by the network analyzer is off. The scope looks fine and everything is behaving how it should except for the bode plot. The magnitude of the bode plot will start at the correct dB then right before tapering off it shoots up a few dB and...
The time domain analysis is easier to plot compared to analyzing the frequency with respect to the phase. But, LTSpice makes it look really easy. So, for a small signal AC analysis, LTSpice does use a AC voltage source for its frequency domain analysis function. This must be a really convenient...
Here is the example and solution in full. I have circled where I'm at and highlighted the part that's tripping me up.
I managed to get...
and getting everything in terms of the angular frequency seems to be critical for getting the plots for the Frequency Response.
I checked my notes on RC...
Hi
Can anyone help with this? I understand what the bode plots should look like but I am not sure how to produce a plot in excel for them without any values
The transfer functions are:
Vout/Vin = 1/(SQRT(1+(ω/ωc)^2)
and
Vout/Vin = -G/(1+j(ω/ωc))
As both are first order filters they will have...
Homework Statement
A scalar is given by
It is controlled by
With step time h = 0.2 s
1. Find the discrete equivalent model
2. Check the stability of closed loop (K = +1)
3. Obtain the via the Bode plot
Homework EquationsThe Attempt at a Solution
So for question 1. This is where I'm...
Homework Statement
[/B]
The filters of FIGURE 4(a) to (c) where designed using a commercial software package (http://focus.ti.com/docs/toolsw/folders/print/filterpro.html)
Write a report (of approximately 750 words) that discusses and compares the design of each filter in terms of their...
Homework Statement
I am working on the following problem:
The Attempt at a Solution
I have the solutions, I just don't understand:
I know that the pole should be the root of the denominator? but in all the examples I was given they used s and not jw, so what is the variable in the network...
Homework Statement
I have a question related to taking the logs of transfer functions, getting the individual Bode plots of each subsequent factor, and adding those plots graphically.
I'm working from Fundamentals of Electric Circuits, 5th edt. Let me start with the following screen capture...
How can we determine the system properties (natural frequencies & damping ratio ) practically using forced vibration?
One way is to measure the phase angle, using the bode plot, the exciting frequency corresponding to 90 (deg) phase shift should be the natural frequency, are there any other...
I have drawn a bode plot(freauency response), but it is not the same with one which is attatched in paper.
Using this data, I have drawn the graph using matlab.
I just put data into second order vibratoion system which is given in the paper(eq 18)
Peak location of graph in paper is just in...
I think that first peak of the graph represent a resonance frequeny but i don`t know some peaks which are located after first peak.
Is it a just noise? or some other?
Hello,
After long time i am able to find Laplace transform function but can't understand the bode plot which give information of frequency response and magnitude i think
plaese anyway here how can push my thinking ahead in it?
Hi ,
I was hoping you could look at this link and let me know if I have interpreted the method correctly
http://i.imgur.com/5axTiBN.jpg
As I understand it the transfer function has had s replaced by jw but also the top and bottom are divided by 10 -
This is so that the brackets on the bottom...
I'm trying to use LTSpice in order to fine tune LC circuits, but a road block I've hit is that when I run the simulation and generate a bode plot, the previous plot is overwritten, so I can't visually compare the effects of the L C changes. Some graphing programs have a function that let's you...
Homework Statement
Below is the bode plot of return difference, 1+C(S)P(S) in a feedback system. Identify the frequencies where the feedback is large, negative, positive and negligible.
P(S) = \frac{100}{s^2+2s+1}
C(S) = \frac{220(s+50)}{s+200}
Homework Equations
Bode Plot, Feedback
The...
Homework Statement
What is the effect on the phase and gain margins of a system when a Phase Lead Controller/Compensator is added?
Homework Equations
I have designed the phase lead controller for the system so if anyone wants to see it, please ask
The Attempt at a Solution
I know, that in...
I am ploting bode of resistor connected with DC source.So no freqvancy at all! The bode magnitude plot should be(or it
should start from) 20*log(jw)=20*log(0) (jw=0 because we have dc source) what should be the value??for step of 5v... what
should bode look like??
So, I have made an experiment of a low pass filter, and made a bode plot out of it. My experiment was done 100 percent in Japanese and this means I cannot understand completely the experiment I have done. So, there is a statement there saying the higher the frequency of the input voltage, the...
Homework Statement
Find the Bode Plot, and the phase and gain margins for the uncompensated system.
Homework Equations
G = (3.6s+6)/(s(.1s^2+.7s+1))
The Attempt at a Solution
I understand the phase and gain margin ideas, but the gain margin hinges on the phase crossing -180 degrees, and in...
Homework Statement
Homework EquationsThe Attempt at a Solution
Hello, In part (b), I found ##k_{cu} = 0.5##. I found in part (d) a controller gain of ##k_{c} = -0.3## yielded a diverging output. Here are the bode plots for parts (a),(c), and (d). I don't understand how I should use the...
Hey there!
So I have this circuit:
with R= 1kOhm and L=10mH
and for some reason the theoretical and real values differ drasticly for lower frequencies
Brown lines are representing the asymptotic and approximation lines.
Blue lines are connecting my measured values.
Amplitude is the amplitude...
Homework Statement
\frac{0.5}{1 - \frac{3145j}{w}} , sketch the bode plot
Homework EquationsThe Attempt at a Solution
Moving the jw to the bottom
\frac{0.5}{1+ \frac{3145}{jw}}
Let s = jw
\frac{0.5}{1+ \frac{3145}{s}}
= \frac{0.5}{\frac{s+3145}{s}}
= (0.5) \frac{s}{s+3145}
=...
Hi all,
1. Homework Statement
http://imgur.com/kqZK1Vv
This is the loop gain (A.F.) of unity feedback system.
I need to extract
DC Gain
Bandwidth
GBW (is GBW Gain Bandwith ?)
f unity (I suppose this is unity frequency)
Phase Margin
Gain Margin
What is the optimal PM and f2/GBW for time and...
Homework Statement
In the figure, the Bode plots of a continuous-time plant (thin line) and of its discrete-time counterpart, representing the discrete-time operation of the plant preceded by a Zero Order Hold (ZOH) (bold line), are displayed. What is the Sampling time used?
Homework...
Homework Statement
Hi,
I'm given a transfer function, and am suppose to draw Bode plot from it.
H(s) = ( 2000s (s - 1) ) / (s + 2000)^2
I'm wondering what to do for the zero at s = 1? Should I just solve this normally, as every example we have done and every example I've seen uses simple...
Homework Statement
Make a blode plot of a series RC high pass filter (log(gain) vs. f)...
Homework Equations
log(Gain)=log(Vout/Vin)
I'm pretty sure the "Gain" is just the transfer function, for a highpass it should be the V_in = Vsupply, and V_out = V_capacitor.
The Attempt at a Solution
I...
Homework Statement
Find the transfer function for the filter on the attached picture and sketch it in Bode diagram, if you know ##Q_0 =\frac{\omega _0L}{R}>>1## and ##\omega _0^2=\frac{1}{LC}##.
Homework EquationsThe Attempt at a Solution
If I am not mistaken, we defined the transfer...
Homework Statement
I'm trying to make a theoretical Bode plot of a High pass filter (made up of a capacitor and a resistor). The transfer function is:
##T=\frac{V_{out}}{V_{in}}= \frac{R}{R+1/(j\omega C)} = \frac{1}{1-j\omega_0 / \omega}##
With a corner frequency of 5 kHz or in...
Hello,
I have the following problem ( which should be uploaded below the text )
I've done part a) correct, I know how to sketch the bode plots but don't know how to find the gain in order to draw correct magnitute response bode plot. This is where I am stucked and if I find out how to find...
How did they get the blue box? I know where they got the 0.5 inside the brackets from but not sure about the rest.
The bode plot in my data book has log10(wt) as the x-axis..
Homework Statement
Homework Equations
The Attempt at a Solution
Hello,
I am having serious problems being able to draw bode plots. At first the professor said to put everything into standard form with an (ω/ω_c)...and then there is also a table in the textbook with standard forms that don't...
Homework Statement
I need some help with the following problem (it is from an old test paper).
Below is the Bode plot of the open loop gain of an amplifier:
A constant fraction β=0.1 of the output is fed back to the input. This feedback does not load the amplifier.
Using the Bode plot...
Bode Plot It's The biggest one in the entire universe!
Homework Statement
The question is stated at the top of the image below.
Did I answer the TWO questions with this image?
https://fbcdn-sphotos-c-a.akamaihd.net/hphotos-ak-frc3/t1/1891009_10151901549150919_346181425_n.jpg...
I have a question
I'm wondering in bode plot
we write the horizontal axis w rad/sec
what does this mean?
is it normal scale 0.1 0.2 0.3 ... etc with equal distances?? it's clear not because it's drwan on semilog paper
if it's the horizontal log w
why then we write 0.1 ,0.2 ,,1 ...
Given an equation like 2/((jw)^2 +54jw +44), how would you find the critical frequency?
I am getting a umaginary number and I am sure this is not true, please help!
Homework Statement
Given this function in an open loop control system
http://img255.imageshack.us/img255/3686/700qa.jpg
Draw a bode plot of the transfer function: The upper graph will present the lines for each of the amplification factors for each of the system components, the lower...
Homework Statement
http://www.wifstrand.se/Albert/stuff/p13.3-6.png
Homework Equations
From circuit analysis I've found the network function to be
H(ω) = -(10^(-4) +jωC1)/(1/R2 + jωC2)
(could be wrong)
The Attempt at a Solution
I don't know how to determine the network...
Hey guys. I was wondering if anyone could give me some hints or help me understand well how to get transfer functions off bode plots. Here is an example I need to solve:
http://i1226.photobucket.com/albums/ee410/jean28x/bodeplotcalc.jpg
This is the Bode plot of a Broadband Bandreject Op Amp amplifier. The exercise says this:
I know that in order to get both cutoff frequencies I need to subtract 3 dB from the plot, but how do I get the gain? I would think that the gain is 3 dB because it is also the distance between the top of...
Can anyone tell me how to find the gain bandwidth product from bode plot of a unity gain circuit for the attached bode plot?
I hv attached the circuit and bode plot ...
I'm stuck on a really simple problem because I haven't done MATLAB in a while. I have transfer functions for nth order lowpass Butterworth Filters:
H(jw) = 1/(s + w_c)^n
I want to plot the 1st to 5th order filters. How do I input H(jw) into matlab? The tf(num, den) is not efficient in that...
Homework Statement
http://img832.imageshack.us/img832/7517/captureax.jpg
According to the solution, the cutoff frequencies are 1, 20, 80, 500 and 8000. I don't understand how to get those answers by inspecting the plot.
Homework Equations
None
The Attempt at a Solution
I think the...
Homework Statement
What is the transfer function described by this bode plot:
http://img96.imageshack.us/img96/4775/capturegib.jpg
*The answer is 3s, but I don't know where it comes from.
Homework Equations
None
The Attempt at a Solution
Correct me if I am wrong. A bode plot is a...
For a transfer function of G(s) = 100 / (s(s+5)), I'm having trouble finding the initial magnitude in dB. It's a type 1 system. If it was a type 0 system with only (s+5) in the denominator, the initial magnitude would be 20log(nominator/denominator) where s is an element of 0, and would decrease...
Homework Statement
I have the transfer function:
for the circuit:
The component values are know, and are:
R1 = 47kΩ
R2 = 4K7Ω
C = 10nF
Homework Equations
The Attempt at a Solution
I have derivied the transfer function but have become stuck on plotting the bode plot.
I understand...
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...