Questions tagged [pole-zeroplot]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
10 votes
1 answer
3k views

What does a Bode plot represent and what is a pole and zero of a Bode plot?

I studied Bode plots and the author of my book is somehow relating zeros of transfer functions to Bode plots. What is the relation between zeros or poles of a Bode plot and transfer function? We ...
user avatar
  • 125
10 votes
4 answers
16k views

Meaning of zeros in transfer function

Can someone please explain, provide a link or cite a book where the properties of the zeros for continuous and discrete time systems are explained? I know that the zeros are the frequencies where the ...
user avatar
  • 231
5 votes
5 answers
408 views

Exciting an RC Circuit at its TRUE Pole on the Sigma (Real) Axis in the Left-Half Plane

Yeah, you probably are reading this question and thinking I'm one of those engineers who hasn't learned about the s-plane. I can assure you I'm not! I know that the transfer function of an RC circuit (...
user avatar
4 votes
3 answers
6k views

Finding Transfer Function, Poles, Zeros of an RC Circuit

I'm trying to brush up on some electronics theory and am working through this PDF. At the bottom of page F-6 there is a problem, F.1, that I am currently trying to solve. The circuit is as follows: ...
user avatar
  • 20.3k
3 votes
6 answers
1k views

Why is frequency not measured in db in bode's plot?

While drawing bode's graph paper where Y axis is gain given in db while the X axis is frequency given in absolute value but scale used is log. I think the reason for log scale on X axis is to increase ...
user avatar
3 votes
4 answers
992 views

Why is a capacitor to ground a low frequency pole, instead of a high frequency zero?

In building my intuition about how analog circuits relate to the s-plane, I am wondering why a pole emerges from a capacitor to ground, for example in a simple lowpass filter consisting of only a ...
user avatar
  • 163
3 votes
2 answers
12k views

What exactly is Pole Frequency in a Filter and how does it affect the frequency response?

I'm having great trouble understanding the concept of a pole in a real world electric circuit. I do understand what a 'pole' is and what a 'zero' is, in the point of view of a 'Transfer Function' but ...
user avatar
  • 379
3 votes
1 answer
478 views

Identify zeroes of circuit by inspection

In a circuit, we can approximate the poles of the transfer function by calculating the AC Resistance and Capacitance at every node. For every node we get a pole so a change of slope in the Bode plot ...
user avatar
3 votes
2 answers
1k views

poles and zeroes, why the magnitude plot contradicts the actual definition

I know that poles are the frequencies at which the response goes to infinity and zeroes are the frequencies at which the response goes to zero but when we draw the bode plot or magnitude plot the ...
user avatar
3 votes
2 answers
2k views

Finding desired closed-loop poles from root locus

I am trying to design a P controller (proportional constant only) to satisfy certain overshoot and settling time requirements for my plant. My values for \$\zeta\$ and \$w_n\$ which would satisfy the ...
user avatar
  • 131
2 votes
3 answers
4k views

Switching frequency and controller's crossover frequency in DC-DC converters

In the context of control loop stability of DC-DC Converters, A switch mode power supply is essentially a sampled-data system, therefore the theoretical maximum bandwidth is one half the switching ...
user avatar
  • 2,642
2 votes
2 answers
688 views

Meaning of the "pole" of a transfer function with time delay

I learned in basic control theory that we can determine the stability of an LTI system by the signs of the real part of the poles of its transfer function \$H(s)=\frac{N(s)}{D(s)}\$. For a rational ...
user avatar
  • 143
2 votes
1 answer
239 views

Complex conjugate poles for OTA unity gain

So I am designing an OTA, exactly like Miller OTA, but I tried to see the behaviour without Miller compensation. The circuit diagram is shown below As seen there is no compensation network, neither ...
user avatar
  • 169
1 vote
2 answers
388 views

Low Pass Filter Wrong Pole Location

I wanted to understand and derive an equation of simple low pass filter that shows the location of pole in frequency response graph (Bode plot). So, here is the derivation: $$V_{OUT}=\frac{V_{IN}*...
user avatar
  • 2,310
1 vote
2 answers
102 views

Zeroes of transfer function

In 'Franklin F kuo's book it is written that "The zeroes of transmission of the ladder occur at the poles of The series branch impendences or at the zeroes of shunt branch impendences" here ...
user avatar
  • 1,124
1 vote
3 answers
263 views

Stability - Driving a Capacitive Load

I know I have been asked not to provide video links and ask questions. But I have no proper guide/mentor or anyone who can provide me better answers other than users in this site. So, please pardon ...
user avatar
  • 2,642
1 vote
2 answers
1k views

The Pole Frequency of OP AMP 741

I am working on MatLab simulation software to plot a Bode plot in the Matlab Environment. The open loop transfer function is $$a(s) = \frac{a_0}{(1+s/\omega_1)(1+s/\omega_2)}$$ Where \$\omega_1\$ and ...
user avatar
  • 329
1 vote
2 answers
2k views

Conjugate, non-conjugate and single poles in an RLC circuit system

In all the texts I encountered so far, I find the following pole-zero diagram example for an RLC series circuit: The transfer function for the above circuit can be found as: H(s) = XC/(R + XL + XC) =...
user avatar
  • 11.4k
1 vote
3 answers
577 views

What happens to an electrical system at its pole?

Pole is defined as the value at which value of a function becomes infinity. Let's say I have one LTI system with transfer function H(s)=1/s+1. How the system will behave when s=-1. From Bode plot ...
user avatar
  • 61
1 vote
1 answer
675 views

RHP zero with a positive phase shift

All books and references I read say that RHP zero gives a negative phase shift. I can infer that by plot the phase of the function \$w_{z}-s\$ where \$w_{z}>0\$. With this function, when frequency ...
user avatar
  • 1,633
1 vote
1 answer
1k views

Poles from Bode plot

How does one deduct the number of poles from a Bode plot? Is it further possible to decide where the poles are? I have not understood this concept even though there is so much focus on Bode plots in ...
user avatar
  • 45
1 vote
4 answers
7k views

What is the difference between the forward transfer function and closed-loop transfer function?

We can define the forward transfer function as $$l(s)=g(s)r(s)$$ Thus, the closed-loop transfer function is $$h(s)=\frac{g(s)r(s)}{1+g(s)r(s)}$$ with \$g(s)r(s)\$ the multiplication between all the ...
user avatar
1 vote
1 answer
348 views

Magnitude of a Transfer Function

So I have an unknown circuit with a plot like this: From this I have to determine a likely transfer function model. It looks to me like there is a pole at 50 rad/sec and a zero at 1500 rad/sec, with ...
user avatar
1 vote
1 answer
360 views

Centroid from calculated root locus is different to the one from MATLAB

Hi all hope someone can help me here. My problem involves the transfer function G(s)=(s+32.8)/((s+2.8)(s+5)(s+27.8) ) As far as im concerned the centroid is ...
user avatar
1 vote
1 answer
533 views

Bode diagram of a single complex pole and under-damped system

I would like to draw Bode plot for a complex pole as below. Let's assume that for now regardless that the single complex pole doesn't exist. This is the function: $$H = \frac{1}{s - (a + jb)}$$ where ...
user avatar
  • 1,633
1 vote
1 answer
889 views

Lead Compensator for double integrator

I am an autodidact in control engineering and I have been trying to design a lead compensator for double integrator system so that the closed loop poles have damping $$\zeta=0.5$$ and natural ...
user avatar
  • 855
1 vote
1 answer
538 views

Confused about the shape of 3D s-domain plots

Why in these type of 3D plots does the gain value (z axis) come back down from infinity for sigma values that are greater than the sigma value of a pole? I thought that these plots are the value of ...
user avatar
1 vote
0 answers
38 views

How can you change the precision of the pole zero ouput in HSpice?

I'm extracting the poles and zeroes of a circuit using HSpice, but I need it to be as accurate as possible. HSpice is only giving me 6 decimal places, and I'm wondering if it would be possible to ...
user avatar
  • 21
1 vote
1 answer
239 views

spike in the Full bridge SMPS

I have a full bridge SMPS and I am measuring the voltage across the output´s diodes on the secondary side. As you can see the voltage spike changes by changing the output current, for example at zero ...
user avatar
  • 73
1 vote
1 answer
602 views

A question on the response of an RC circuit and pole of its transfer function

Below is an excerpt from an introductory level book about poles and zeros: The transfer function of the RC circuit system above for the output voltage is: H(s) = s/(s+10) The book claims that this ...
user avatar
  • 11.4k
0 votes
1 answer
2k views

Intuitive to get pole and zero points for lead compensator

The circuit below is a lead compensator. I can easily know exact the pole and zero of the network by deriving the transfer function. However, I am wondering if there is an intuitive method to get the ...
user avatar
  • 1,633
0 votes
3 answers
1k views

Zeros and poles in the following bode plot

According to the definition, zeros are the frequencies which make transfer function to be zero, and poles are the frequencies which make transfer function to be infinity. The definition can be seen ...
user avatar
0 votes
2 answers
938 views

Find the Zero of a simple circuit

I would like to better understand how to find the zero of the transfer function of a circuit by inspection using fast analytical techniques. simulate this circuit – Schematic created using ...
user avatar
  • 3
0 votes
2 answers
154 views

Do we analyze real poles the same way you analyze complex conjugate poles?

So I am analyzing a filter and I came up with the following expression for the transfer function in its canonical form: $$\frac{987654 + 4666.67 s + 1. s^2}{2.48519 \times10^8 + 52316.2 s + s^2}$$ ...
user avatar
0 votes
1 answer
150 views

Sketch a Bode Plot for the Loop Gain of the circuit

Below I have the transfer function, but I am still uncertain about Bode plots. How do I know the slope, how do I know where the zeros of the function are?
user avatar
  • 141
0 votes
2 answers
991 views

Poles and Zeros of Two Pole Compensation

I am known with the basics of what poles and zeros of transfer function are and how to determine them, but I certainly don't know how to apply such poles and zeros to the gain curve, which describes ...
user avatar
  • 2,310
0 votes
3 answers
346 views

No zeros, yet still affecting stability?

As far as im aware Poles affect the stability of a transfer function primarily, and is defined whether they stay within the unit circuit & are on the left side of the pole-zero plot. Zeros have no ...
user avatar
0 votes
2 answers
1k views

Polar plot of s/(1+(s*T))

The magnitude at w=0 comes out to be 0 (=1/infinity) , which is different from previous problems (they didn't have any zero) I've calculated, is this right? I guess it should be right (because G(s)...
user avatar
  • 582
0 votes
1 answer
1k views

How are poles of Bessel filter related to cutoff frequency?

For a 2nd order Bessel low pass, I have a pole-zero map which has a pole couple of the form: \$p_{1/2} = a \pm jb\$. Can I deduce the cutoff frequency from the pole location? Does it contain any ...
user avatar
  • 309
0 votes
3 answers
1k views

How is the impulse response related to pole/zero-plot?

I have trouble understanding how you can from a pole/zero-plot say something about the impulse response. For instance I have 2 poles in (-5 +/- 8 jw) and a zero in 0. How would I know, from just ...
user avatar
  • 5
0 votes
2 answers
6k views

Type of Filter from pole-zero plot

If the zeros were on the imaginary axis, it sure would have been a NOTCH filter. But, since the complex conjugate zeros are on the left of the jW axis, the transfer function has second order terms ...
user avatar
0 votes
1 answer
107 views

Finding the position of a zero without doing explicit calculations

I have the following circuit: It is a fully-differential amplifier. Since the circuit is symmetrical with respect to the vertical axis, only the right portion (for example) can be studied to find ...
user avatar
  • 596
0 votes
3 answers
142 views

Breakpoints, poles and zeros of a band reject filter

I'm reading a manual about op. amps. (op amps for everyone) which, at a certain point, speaks about poles and zeros. I'm trying to understand the following example: Given the following band reject ...
user avatar
  • 965
0 votes
1 answer
177 views

Bode Plots and Electrical Circuits - Zeroes and Poles

I would like to understand more electrically with little math (transfer function) involved regarding Poles and Zeroes in a control system (Feedback in DC-DC Buck Converter to be specific). I ...
user avatar
  • 2,642
0 votes
1 answer
357 views

Effect of zeroes in stability

I thought earlier that zeros have no direct effect on stability but when I read the below article of Wikipedia where it said under the heading "Effect of poles and zeros " It says that adding zeros ...
user avatar
  • 265
0 votes
1 answer
689 views

Root locus for an open loop transfer function?

The function, rlocus(), in MATLAB is used for closed loop system roots for variation in gain K. However, I am curious if there is a similar function for variation ...
user avatar
0 votes
1 answer
89 views

How to find the frequency of more than one zeroes analytically?

Hello, I have to draw the Bode plot of \$G(s)=\frac{V_u}{V_{in}}\$ and I want to do it without calculating the full transfer function. This circuit has Cgd=1pF capacitors at every Mos. Vt=0.4V, k=2mA/...
user avatar
0 votes
2 answers
186 views

How do you determine the approximate frequency where the magnitude starts decreasing -40dB/dec for complex pole?

I am stuck at drawing the approximate Bode plot for the complex pole transfer function as below. Please see the question and problem in the picture. How do you determine the approximate frequency ...
user avatar
  • 1,633
0 votes
0 answers
173 views

Pole zero cancellation amplifier circuit

I've built the circuit which looks like this: At the input comes pulses from 30 volts biased photodiode. After adding parallel 4.7 nF and 10kΩ for pole zero cancellation everything works fine, in AC ...
user avatar
0 votes
1 answer
146 views

Break in and break away point

Consider the open loop transfer function of \$\frac K{s^3+2s^2+2s}\$. In a negative feedback system, that has three poles \$0, -1+i ,-1-i\$. Is there any break-in or break-away point because only one ...
user avatar