Questions related to Impedance
I simulated an antenna with a matching network. Now to calculate the antenna range using Friis equation I need to know the losses due to the matching network.
Can anybody suggest how can I find the losses due to the matching network? I prefer to use software.
I run an impedance test with mild steel coated with polymer coating. The impedance is showing very abnormal pattern as shown in the pic. On the other hand, when I was running the same Nyquist test with stainless steel it is showing quite a normal graph. Can someone suggest me the real reason why the impedance data is showing very abnormal reading. Thank you.
Working electrode : Polymer coated mild steel sample.
Reference : Saturated calomel electrode
Counter : Graphite counter electrode
SIL is define as when transmission line loaded with Impedance equal to its Surge Impedance ignoring Resistance and conductance. When Surge impedance is equal to load impedance the sending end and receiving end voltages are equal.
Battery impedance is a combination of internal resistance and reactance where internal resistance + reactance, or (L+ C), equals impedance when using an ac stimulus. The internal resistance of a battery is made up of two components: electrical, or ohmic, resistance and ionic resistance.
I face a very lossy line (cryogenic harness) with L = 320 nH/m, C = 60 pF/m and R = 10Ω/m characteristics. I can estimate the characteristic impedance of this transmission line as Z0=√L/C~70Ω. with 2 meters length, the lossy part is about R = 20 Ω. My simple question, is, if I want to amplify the end of this line with a good input matching, what LNA input impedance have I to match ? Z0 line impedance ? Z0 "+" R line impedance "+" resistance? Source impedance Rs? Source impedance Rs + losses R?
I wonder if someone can give a clue on how to do fitting if, in a high-frequency region, there is a kind of hook. Please find the files attached. The system is a water-soluble biopolymer in buffer solution, liquid EIS, electrodes: Carbon (WE), Ag/AgCl (RE), and Pt wire (CE). OCP. I've got minimum errors at using this equivalent circuit.
Dear RG community members, this pedagogical thread is related to the most difficult subject among the different fields that physics uses to describe nature, i.e. the physical kinetics (PK). Physical Kinetics as a subject is defined as a “method to study physical systems involving a huge number of particles out of equilibrium”.
The key role is given by two physical quantities:
- The distribution function f (r, p, t), where r is a vector position, p is a linear momentum and t is the time for the function f which describes a particle in an ensemble.
- The collision or scattering term W (p, p¨) gives the probability of a particle changing its linear momentum from the value p to the value p¨ during the collision.
If the following identity is satisfied for the distribution function df (r, p, t) / d t = 0, then we can directly link PK to the Liouville equation in the case that the distribution function does not depend on time directly. Physics students are tested on that, at the end of an advanced course in classical mechanics, when reading about the Poisson brackets.
However, is important to notice that not all phys. syst. are stationary and not always the identity df /d t = 0 follows, i.e., the distribution function - f is not always time-independent, i.e., f (r, p) is just true for some cases in classical and non-relativistic quantum mechanics, and the time dependence “t” is crucial for the majority of cases in our universe, since is out of equilibrium.
In addition, physical kinetics as a “method to study many-particle systems” involves the knowledge of 4 physics subjects: classical mechanics, electrodynamics, non-relativistic quantum mechanics & statistical mechanics.
The most important fact is that it studies the scattering/collision of particles without linear momentum conservation p, where: the time dependence & the presence of external fields are crucial to study any particular physical phenomena. That means that PK is the natural method to study out of equilibrium processes where the volume of the scattering phase space is not conserved & particles interact/collide with each other.
If the phase scattering space vol is not conserved, then we have the so-called out of equilibrium distribution function which follows the general equation:
df (r, p, t) / d t = W (p,p¨), (1)
where: d/dt = ∂/∂t + r´. ∂/∂r + p´. ∂/∂p, with units of t -1or ω/(2π).
The father of physical kinetics is Prof. Ludwig Eduard Boltzmann (1844 – 1906) . He was able to establish the H theorem which is the basis for the PK subject and also he wrote the main equation (1), i.e., the Boltzmann equation to describe the out of equilibrium dynamics of an ideal gas. r´ & p´ in d/dt are derivatives, p¨ in W is another momentum position
Another physicist who established the first deep understanding and condensed the subject into a book was Prof. Lev Emmanuilovich Gurevich (1904 - 1990). He was the first to point out that the kinetic effects in solids, i.e., metals and semiconductors are determined by the "phonon wind", i.e., the phonon system is in an unbalanced state 
Physical kinetics has 3 main approaches:
- The qualitative approach involves the evaluation of several physical magnitudes taking into account the order of magnitude for each of them.
- The second approach is the theoretical approach which involves complicated theoretical solutions of the kinetic equation using different approximations for the scattering integral such as the t approximation. For graduate courses, I follow , an excellent textbook by Prof. Frederick Reif. For undergraduate teaching, I followed the brief introduction at the end of Vol V of Berkeley Phys C.
- The numerical approach since most problems involving PK requires extensive numerical and complicated self-consistent calculations.
The fields where PK is useful are many:
- The physics of normal metals and semiconductors out of equilibrium.
- The hydrodynamics of reacting gases & liquids, quantum liquids, and quantum gases at very low temperatures.
- The physics of superconductors, phase transitions, and plasma physics among others.
There is a quantum analog to the classical Boltzmann equation, we ought to mention three cases: the density matrix equation for random fields, the density matrix equation for quantum particles, and the Wigner distribution function. Main graph 1 is adapted from  to the English language, LB picture from , and LG picture from .
Any contributions to this thread are welcome, thank you all.
2. Fundamentals of physical kinetics by L. Gurevich. State publishing house of technical and theoretical literature, 1940. pp 242
3. Lev Emmanuilovich Gurevich. Memories of friends, colleagues, and students. Selected Works, by Moisey I. Kaganov et. at (1997) pp 318. ISBN:5-86763-117-6. Publishing house Petersburg Institute of Nuclear Physics. RAS
4. Белиничер В.В. Физическая кинетика. Изд-во НГУ.Новосибирск.1996.
5. Lifshitz E., Pitaevskii L. 1981. Physical Kinetics. Vol. 10, (Pergamon Press).
6. Thorne, K. S. & Blandford, R. D., Modern Classical Physics: Optics, Fluids, Plasmas, Elasticity, Relativity, & Statistical Physics (2017) (Princeton University Press).
8. Fundamentals of Statistical and Thermal Physics: F. Reif Mc Graw-Hill, 1965
What will be the equivalent electrical circuit of the following set of multiplied and divided impedances:
Z1 / (Z2 x Z3)
It is assumed that each of these impedances itself represents an element or electrical circuit.
Hi, I was measuring the impedance of carbon materials for ORR using a three electrode apparatus with Hg/HgO as reference. The frequency was 10^6 to 0.1Hz, similar to the literature. However, the measured Nyquist plot was quite strange where at high frequency, the imaginary part was not zero. (it only shows half of the first semi-circle).
Does anyone know the reason for that? Another question is, based on this Nyquist plot, how can define the uncompensated resistance of my data?
I`ve attached the screenshots of both Nyquist and Bode plot here.
Thank you very much for answering/suggestions!
I've included an example picture. Is this transition followed by Quarter Wave transfer rules? or, Can anyone assist me in properly identifying this transition section?
I want to deposit silver nanoparticles on glass substrate by thermal evaporation technique.what values of the parameter (accostic impedence,density,thickness) i should take.
I would like to simulate the concrete bar on COMSOL to obtain the electrical properties such as capacitance, permittivity as well as impedance in order to measure the porosity and moisture of the concrete.
The image contains a concrete bar with 2 electrodes (on the top), which is a kind of capacitive device. I would like to obtain the best electrode size and shape.
Which electrical properties (or parameters) are required to investigate the best electrode size and shape for the capacitive device? How to optimize the distance between the electrodes on COMSOL?
Currently, I am performing electrochemical analysis on screen sprinted gold electrodes and extracting Impedance and CV curves. I am new to this field. From the literature, I read that charge transfer resistance is a combined effect of resistance and capacitance. I need only the resistance component. Is there a way to extract it?
Is there any other electrochemical techniques or approach, except EIS, to determine the charge transfer resistance?
I appreciate it if you have any idea. Thank you
I designed a antenna working at MHz range. I got -10 db impedance bandwidth for certain range of frequencies. In that range of frequencies I got a spike in impedance bandwidth for -2db. I tried reducing it. Can somebody help me on how I can approach this problem
I need to verify the results of the classical PEC or İmpedance half plane results obtained by the theory of Physical Optics by using HFSS or CST.
I attached the figures of the geometry and the total wave result for the incident wave angle of 60°, the total wave (=incident wave+geometrical optical wave+diffracted wave) and
diffracted wave in MATLAB.
How can I verify it in HFSS or CST or any suggestion?
The EIS measurements often require the conditions of stable state for batteries. So the perturbation signals for EIS measurement are low, such as 5-10 mV for the perturbation voltage. However, the EIS measurement time is usually long, such as 10 min or even 30 min. In this case, the battery may not locate at stable states. For example, the battery temperature or SOC is changed. Thereby, the measured EIS under the unstable state is not the true EIS at the setting point. Exactly, many factors would influence the EIS measurement. Which one is dominant? Which one is inherent?
I want to find the resonance and anti-resonance frequencies of an ultrasonic transducer by analyzing its impedance.
so I need to buy a impedance analyzer or spectrum analyzer or something like that.
but my budget is limited.
do you recommend any device for my application and limited budget? :D
I'm designing a CPWG in the 30 GHz range in HFSS. I noticed that in my design the characteristic impedance is variable across my simulation range from 15-50 GHz. I think this is to be expected but more importantly the impedance of the line seems to be quite sensitive to the port definition. If I use the suggested wave port width the port overlaps with the coplanar grounds and the impedance drops from 52 ohm to 14 ohm. Any suggestions or tips on how to accurately do this and ensure no artifacts from the wave-port definition?
is it possible to make a DIY impedance analyzer for checking the resonance frequency of high power ultrasonic transducers? for example a face mask welding ultrasonic transducer
For my research on inkjet-printable electrodes, I want to compare the capacitance/impedance of a parallel-plate capacitor with a planar interdigitated capacitor.
In order to verify my simulation results, I additionally want to calculate the capacitance/impedance of the interdigitated electrodes analytically, dependent on geometry and material properties.
Can somebody provide some formulas and/or respective source where I can find how to calculate such a structure?
I have designed a split ring resonator with a metal ground so my S21 is zero. How can I plot the permittivity and permeability and impedance in HFSS?
Since I have used metal ground I also can't find the phase of S21.
Hi all, I get my admittance data using Impedance Analyzer for the PZT transducer attached to a plate. I measure three times with 15 minutes interval on the first day (fig.1) and then measure three times with 15 minutes interval the next day (fig.2). The obtained curves are different in the same day and also in the different day (fig.3).
I read papers but cannot find how to explain this phenomenon. From the theoretical expression of admittance or impedance, it seems the capacitance of PZT contributes to this difference, if my guess is right, why the capacitance of PZT varies everyday? (The temperature are 25 ℃ with +/- 3℃). Could anyone help to give any hints or references about this? Thanks.
Please explain VersaSTAT MC Multi channel electrochemical system with details regard handling of software for a VersaSTAT Studio, please how/where to set potential window value and Where to set the Current Density value (1A, 2A, 3A or mA) into Charge-Discharge in order to supercapacitor form a charge discharge experiment.
Using VersaSTAT chronopotentiometry, what is the procedure of cyclic charge discharge method procedure step wise, 1) where to set applied potential and current density value (A or mA). CV and Impedance much better.
Please anybody help me how to what is the procedure using in (VersaSTAT Studio) software chronopotentiometry charge discharge options and settings.
please mention references for the same.
Recently, I'd like to collect some formulas for some specific transmission line structures in PCB (single-ended stripline, single-ended microstrip line, etc)
I found that there is no formula related to the impedance of the microstrip line with solder mask (the region above the solder mask treated as the vacuum or the air)
Is there any suggestion to find that?
Thank your reading
I am trying to understand impedance spectroscopy for resistive switching studies. I am wondering what would be the best resource to start.
Thanks a lot
I have designed a patch antenna in HFSS for 2.45GHz.
S11 is around -44
But the problem is with gain which in -ve in dB scale.
I could not understand why? What may the reason for that?
Can someone help me?
I am attaching the plot for your referance.
I am working with a Silicon Substrate based sensor and getting CV curve with Initial and Low voltage -0.2V and High voltage 0.4. However, in the EIS test, the Nyquist plot is not giving the circular shape it's supposed to give at the beginning. I am using CHI660E and in A.C. Impedance test, do I need to set the peak voltage at which I am getting the oxidation peak? Also what should be the voltage range of CA depending on the CV parameters? Your help would be really appreciated.
One of my colleagues said, "the impedance you can measure with the three electrodes and with the specific sequence varying the frequency"
Is it possible to configure the potenciostat without the FRA module, with these settings? If so, how could I do that?
I am trying to plot a surface impedance of a metal patch vs patch dimension (square patch). I have designed a unit cell consisting of a grounded substrate, a patch on the top of substrate, master/slave BCs on the four sides of my unit cell and a Floquet port on the top.
For some reasons that i don't really know, I can't obtain the expected results .
Please could someone help me find out what I am doing wrong?
Thanks in advance.
How can I fix the port impedance in HFSS for an RFID Tag? In my simulation I always take it the conjugate of the Chip impedance but I never validate it by the measurement. I want to know if there is some other method to fix the port impedance in HFSS or if this method is right is there any one who validate it by the measurement?
While performing measurements , using a solartron based Impedance analyzer (with range 36 micro Hz-36 MHz), i am facing the same repetitive pattern of noise/oscillations during frequency sweep from 1 MHz to 0.1 Hz, even at 0V DC.
Noises are being observed in specially 3 regions of frequency, as shown in attached figure.
1) First one is above 1 MHz
2) At or just below 100KHz
3) Below 100Hz (Exactly at 50MHz) & heavily random noises towards 1 Hz.
The above 3 Noise /oscillations are dominating/ growing with increasing Dc voltage.
At 50Hz (as shown in 2nd figure) , it is expected to be the interference of outside Ac noise of 50 Hz( as we are not using Faraday cage) but what about the other frequency ranges ? Is it due to the aforesaid reason and will be solved by using metal faraday cage during impedance measurement or anything else are the culprits?
Here,for reference, i am attaching 2 figures of measurements, Please let me know the possible reason and their remedies for smooth Impedance data.
When building a circuit using Impedance Model Editor in Gamry EchemAnalyst software I am getting the warning "One or more components has missing wires".The images with warnings are attached. Can anybody suggest the exact way to biuld a model circuit avoiding these warnings?
I get the impedance values (real and imaginary parts) from the EIS technique. Can we correlate to it any dielectric property (dielectric loss, dielectric strength, or dielectric constant) using an equation, etc?
I am testing the impedance of a material that will be used for ECoG electrodes.
I was told to test it at a frequency range from 1 Hz - 100 kHz but why is this range used? I wasnt able to find a satisfactory answer.
Which impedance values are good for recording and why? Is there a range ?
Our lab has developed lower limb exoskeletons for gait training and rehabilitation.
The exoskeleton implements low and high impdenace through force-sensor based impedance control.
In this case, the user's dynamics such as weight, muscular force, joint impedance are considered as a disturbance.
I want to operate the impedance of the whole dynamic model, including robot as well as human.
For example, the robot user can feel his leg as a baby's leg under the low impedance mode.
If anyone knows how to implement this condition by using the exoskeleton, please attach any articles in the comments.
anybody can suggest an equivalent circuit for this impedance data? i tried so many models based on the may occur in my system but not fitted. my problem is with the loop in the low frequency. anyone can explain the probably meaning?
my WE is an copper mate wich i guess a barrier layer formed in the surface and its proof by XPS analysis, but my model not fitting.
i attached the files
I need equivalent circuit to fit in the electrochemical impedance data?
I have separate Equivalent circuit diagram for screen printed carbon electrode and polypyrrole on stainless steel. Kindly refer the attached file.
With thanks and regards,
Eswaramoorthy K V
We checked the impedance of the SCE reference and found that is was about 500 ohms when placed directly in the cell and about 5,000 ohms when using the Luggin Bridge.
By adding more NaCl to the solution in the Luggin we reduced this to about 4000 Ohms
We replaced the frit on the Luggin, but no difference.
are these impedance measurements normal/acceptable?
Can anyone suggest me an equivalent circuit for (CdS thin film/Na2S2O3/Pt) photoelectrochemical cell? CdS thin film is deposited on FTO glass and used as the working electrode. Pt electrode was used as the counter electrode and Ag/AgCl as a reference. Observed Nyquist plot and Bode plot are attached herewith. I have simulated some equivalent circuits such as [R(RC)], [R(RQ)], etc. But the right side bend of the phase curve in the bode diagram didn't match with any of I tried.
Can someone please help me to understand the attached picture of Derivation of Impedance matching.
I know the Fresnal equation but how they have added relative permeability in equation 1 and relative permittivity in equation 2 and then how we got sqrt of relative permittivity in equation 3.
I have attached reference paper also from which this derivation has been taken.
Thanks in advance
I am going to build an energy harvesting circuit, which includes several diodes.
Diodes are non-linear components, whose impedance varies for different input voltage. This means that even for a given level of input power (AC input), the impedance varies all the time.
How can I determine the parameters of the impedance matching network in ADS to fulfill maximum power transfer from an antenna to a non-linear circuit under a given level of AC input power?
How can I check whether the impedance matching network for non-linear circuits is well designed (by using a vector network analyzer or some other methods) in practice?
Please kindly give me some instructions if you know any answer about either of the two questions.
Hello, I am actually working on corrosion in reinforced concrete but I have bad results applying EIS technique. The problem is that in high frequency range I can not get positive values in Z", additionally theta values show negative results and I have read some publications that this is typical of inductive materials.
The problem is that I have run some test without apparent problem but the most of of times I have the above mentioned problem and I think that problem is in connection but I don´t know how to correct this issue
The test is run with a Cu/CUSO4 RE, an inoxidable steel plate as CE and the WE is a corrugated carbon steel bar.
Can someone please help me to understand the concept of Impedance matching in Metamaterial Absorber. I have attached a picture. In the picture at 2.06 GHz, there is peak for Real (z) at and for img(z) is in negative so how its impedance of Metamaterial absorber matching with free space impedance.?
Thanks in advance
Firstly, thank you for being interested in my question and opening this.
I'm having a hard time calculating input impedance by transmission line theory.
I'm a student studying microwave absorbers. In this field, it is necessary to calculate input impedance to finally obtain reflection loss.
I've uploaded a file showing the equation of transmission line theory.
In the equation, I wonder how I can treat 'j' in tanh when I calculate it in excel program.
I've tried solving the tanh part in many ways like this, but I couldn't
I have no idea how I should threat 'j' in tanh
I'd appreciate it if you'd help me to solve this question.
In my bachelor thesis I'm currently performing EIS measurements on sulphated Zirconia using the Autolab PGSTAT302N and Nova 1.10 software. The SZ is measured in form of a pellet of 13mm diameter and 0,5mm thickness. With every pellet sample I'm experiencing noise specifically between 1Hz and 100Hz (see the pictures below). The SZ is loaded with Isopropanol by staying under an isopropanol-containing atmosphere for a specific number of hours. The pellets are then prepared with 10mg of conducting silver-paste on each side. With other samples (textiles) the impedance spectra look fine.
What could be the reason for this and what could I do to solve it?
Thank you in advance.
I want to simulate a coaxial cable in FEKO software. However, the results do not agree with the transmission line solution that uses the transfer impedance (Schelkunoff model). I m thinking that the terminations in the MoM (FEKO) simulation affects the inner circuit. any suggestions.
Also, how can I extract the transfer impedance of a coaxial cable from the MoM results?
check my termination in the attached image.
I use the Johnson-Champoux-Allard (JCA) model to predict a sound absorption coefficient of a rigid material. I've seen a lot of articles where this procedure is done, all the formulas are provided. Unfortunately, what I get is, for example, α = 1.5281 + 0.2485j (at 1500Hz) while it should be a real number 0 < α < 1 instead. I understand that the real part of impedance represents acoustic resistance and the imaginary part - acoustic reactance. But how do I combine these to achieve an absorption coefficient?
My name is Colleen O'Brien, a senior biomedical engineering student.For my senior project I am required to build a model of human abdomen to validate a device we are developing. I still am trying to find synthetic materials with acoustic impedance of 1.69 and 1.53. If you have any advice or recommendation it would be greatly appreciated. Thank you for your time.
Currently, I'm looking for a simulation of the sound absorption coefficient of a micro-perforated panel by using Impedance Tube in Simcenter 3D Acoustic. Is there any tutorial available for Sound Absorption Coefficient? Because mostly I found is for Sound Transmission Loss.
After the simulation, my target is to plot the acoustic impedance value (real & imaginary) vs frequency range. Is it possible? Is there anyone who has done this before. Any help would be much appreciated.
For comparison of Impedance of electro-catalysts, we should give same potential value for all ?or we should give OCP?(which is different for each)?
I am researching an antenna designed to cover the whole W-Band (75-110 GHz) I found in this forum that when we put discrete port with 50 Ohm Impedance, the resulting Z matrix represents the antenna's input impedance. I attached the Z matrix result that I got from CST below.
My question is, since I can only feed my antenna with one line impedance value, how do I determine that value? And since the feeding line will probably have only real value, what should I do with the imaginary part of the antenna's impedance?
In this case I tried averaging the real impedance values from 75-110 GHz and it comes out as 175 Ohm. The antenna showed good return loss when I feed it with 175 Ohm discrete port. Is it a correct way to determine it? Or there is other formula I need to incorporate the imaginary part?
Thank you in advance.
I used an Electrochemical Analyzer Model CHI604E, Made in USA to make this plot and I am not getting the supposed semi-circle plot. Please I need assistance. I used AC Impedance, AC Impedance-Time and AC Impedance-Potential, and all were irregular shapes.
Please someone should reveiw and advise. Attached is one of the plotted graphs.
I am having difficulties in designing stripline on cst. The reference impedance should be 50 ohms and it should be straight line at 50 ohms. Please guide what mistake I am making. I played with the width of the stripline, the impedance varies but it not straight line. Why it looks like a curve?
Thank you in advance.
For a full cell, sometimes people use two RC element two represent two charge transfer process of Anode and Cathode. Sometimes a single RC element is used to fit the curve ( as the time constant is close to each other). How can I decide the RC elements for a LFP battery? I use one Series resistance, one RC to represent both charge transfer processes of cathode and anode, one RC to represent to SEI and another CPE to represent the diffusion.
Mostly I have overlapped Charge transfer and SEI processes, the fitting is very random if I use two RC to represent one complete Semicircle(Nyquist plot).
It would be very helpful if someone help me understand the above uncertainities.
Thanks in advance.
How I can calculate the Impedance of a single white colour LEDs Strip? Does anyone know ?
I have a Strip of white light LEDs , at a Voltaje imput of 12V .
I'll appreciate any help :)