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Hfss Convergence

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I am designing a dipole meander line antenna using hfss for RFID application that suppose to resonate around 1.5GHz frequency. And my Solutions frequency is 1.5Ghz, with sweep setup of fast sweep, sweeping from 500MHz to 2Ghz. I am using a wave port with an air box. I have modeled the antenna in hfss and after the simulation, the (...)
Hi, I have calculated E field and stored energy in a cavity using hfss eigen mode. So maximum delta (resonant) frequency is used as convergence criteria in this mode. Now there is a question: How E field or stored energy can be used as convergence criteria in eigen mode?
hello I am doing simulation on corrugated horn antenna in 15 GHz using hfss . after completing the simulation it gives following warning Adaptive Passes did not converge based on specified criteria. Normal completion of simulation on server: Local Machine. How can i remove this warning message and what do the
It really depends on the problem. This is similar to oversampling: a dense mesh does not always give better results. With the same correct modellization but different solution setup you may endup with different results. To be safe i always try some different convergence criteria to see if the results are the same. I don't know the latest versio
I assume, that you work with a simulator that uses the finite element method (for example hfss). convergence means: One of the points of the finite elemnt method is, that you never get any absolute correct values as a result. The calculation is based on differential equations solved in a small finite space of your object. The object can be div
about the convergence message in hfss v9.0 :() 1. why the 6th and 8th pass gave Delta S in terems of N/A? what does N/A mean? 2. it seems Delta S becomes larger when pass Numbers increasing, I don't know if it's reasonable since I feel Delta S should get smaller with increasing pass Numbers solved. Thanks in advance! the next is a
I am experiencing a similar problem with hfss. I set up the simulation such that at least 5 runs converge. After a while convergence is achieved. Then in the subsequent 3-4 runs, the convergence is achieved. But suddenly at the 4th or 5th run there is an error of %98. Out of 36 runs, none of the 4 runs converged to the same value after one (...)
You probably don't need deltaS that low. It defaults to .02, so unless you need some insane accuracy, you don't need .001. Try setting it at .01. convergence is just when the deltaS gets below that value. Try setting it to deltaS=.01 and then forcing it to do 2 or 3 consecutive converged passes or something rather than a really low deltaS for (I
Hello, I am simulating a 2-18 GHz cavity backed spiral antenna in hfss but I am getting these warnings (mentioned below) in fast sweep when I decrease the spiral arm width to anything below 0.25 mm. I have searched alot on google and hfss guides but there is nothing on these warnings. How can i remove this warning message and what do these war
hi all i want to learn basic concepts for hfss design and is meant by each step in designing this tutorial so that i can design a microstrip patch antenna can u give me a good tutorial of cst microwave studio with lot of examples of design of patch antenna regards kartik Do you want tutorials on hfss or CST
Hi all, Newbee, first post, and still learning the rules and etiquette of this place. Be easy, k. Here's the synopsis: I'm running an hfss driven terminal solution. The design is a spiral transformer--a single loop primary around a flat archemedean spiral of a few turns. I've read in various places that specifying port impedance does no
hi, ansoft guies: There is one simple question about hfss. Since Adaptive 'Single frequency' analysis will allow users to setup 'Requested Passes', what number will be suitable? I used 7. However, issues come up! The results,obtained by 'Single Frequency', differs greatly from 'Sweep' analysis results? Because of the higher acc
Do someone have good skill to simulate in bad computer's hardware??? when i set the higher adative frequency in hfss, the error message show "lambda refinement will create large starting mesh". But i set lower adative frequency, my solution will not convergence. is it hardware's problem??someone kindly help me. Thks......
I am working on microstrip antenna design in hfss 9.0. I learned more about it by the help of traning (A friend gives me) but I don't understand some functions' physical meaning in this program. In solution setup there are options: maximum number of passes and Maximum delta S per pass. If anyone explains their meaning and how to use
hfss initially generate the mesh, then calculate the S-parameters, then refine mesh, calculate S-parameter again, compare the S-parameter difference, if the difference satisfy the stop condition which you set by deta-S, then hfss treat the mesh is ok, and do the calculation and sweep with this mesh file, if the difference dont satisfy the stop cond
How to configure mesh in hfss? Is there any relationship between mesh size and device size or working frequency?
Hello, Can anybody upload(again) the CST and hfss project files for the Sievenpiper's structure? Thanks kato01
Hi, I think your main mistake (which is very common actually) is that in hfss in case of Microstrip lines, the port size changes the results. So you must adjust the port size to get an input impedance of 50 ohms, which is actually not a very pleasant task. also you should check the convergence and increase the maximum number of passes in case o
Hi, I think you might have problems with plane wave excitation. Try to use the solver view option from hfss, to ensure that plane wave excitation is not overridden by other boundaries. also chek for convergence (let the minimum converged paths be 2 or 3). BR Adel_48
Hello guys, I have big problem with simulation accuracy of hfss. I simulate an electrical small antenna(meander line antenne) with radiation boundary of a airbox. The results depend too much on dimension of the the airbox, although the mesh is fine and the convergence is also okay. The hfss-modell has been attached, run the parameter sweep (...)
Setting delta S is very important in designing some passive componets using hfss. i wanna know how to set it in a detail design and what I should consider in the design ? for example , designing a microstrip filter or a waveguide filter. thanks !
Yes, the waveport in hfss can have lossy dielectric and/or good (non-perfect) conductor. my guess for your problem: 1. 2xTsub is hardly "large" enough, check convergence w.r.t. all the sizes that you set to be around 2xTsub. 2. make sure you understand the unit of the hfss answer correctly.
Dear abhi_kolkata: Try forcing hfss to take more adaptive passes. Sometimes it shows error convergence when error convergence has not really been achieved. Sometimes, you get two adaptive passes that happen to have about the same amount of error, which can fool the convergence criteria tester to think you have achieved (...)
Hi, I have many questions as follows.If you are free,please give me advices. 1. As I simulate a transmission like structure,such as Microstrip line,two solutiion types can be choosed.I run the simulatiion separatey and get different resluts(for Driven modal,the mode number I set up is one).Which one is correct? 2. The number of mod
I simulate a horn antenna by hfss.But i find the gain G is smaller than the directivity D. Usually ,G=ε × D , ε is efficiency ,0<ε≤1.
What results are you looking to get from hfss? a) Be sure to check the current distribution. Se my posts in: b) Do a convergence analysis by comparing s-parameters of runs with decreasing Delta-S error tolerance AND port error tolerance (if using wave ports). Do this in MWO also
I would recommend using more than 3 adaptive passes as a default. For hfss, I usually set deltaS to 0.005 and maximum number of passes to 10 or 12. Check the convergence before viewing the results. It is a good habit to get into. Also remember that converging on input impedance is no guarantee that the radiation boundaries (and therefore gain,
(1) Using a radiation boundary that is lambda/4 away from the transmission line should be fine. Since you are not simulating an antenna (strong radiator), you may could even use a PEC boundary if its far enough away from the transmission line. Since the signal is propagating down the microstrip line and not into free space, as long as you don't int
If you post your project I can simulate it in hfssv10 to see if the directivity problem is fixed in the new version.
I'm trying to simulate a spiral small antenna in antenna should work at 434 MHz.Firstly i did a fast sweep simulation( between 400 MHz and 600 MHz) to determine the resonant frequency of my design.then i did a setup simulation in this frequency to have radiation parameters. My problem is that during the 2 simulations i have not the same res
Anyone knows the term of 'non-converged solutions' and 'meshing' in hfss? What does it mean by 'poor meshing'? How to measure how poor it is and then how to improve it? Thanks so much zahril You can read a book: Swanson D., Hoefer W., Microwave Circuit Modeling using Electromagnetic Field Simulation, 2003 There
hi everybofy; i have some problems about hfss. there is a variable, named "solution frequency" in hfss/Analysis setup/add solution setup. i dont know the meaning of this variable. when i changed this value, the S(21) caractersitics shift and change. what must i do or where am i making wron? and sometimes, when i move the simulation directo
See the attached hfss file. Apparently, S11 and S12 have artificial resonace around 1GHZ due to interpolation. This can be verified by sweeping using discrete type. does anyone have good idea how to solve the problem?
Hi, everyone, i am designing a filter now. And firstly i want to get the resonant frequency of a SIR with a dielectric surrounded. I know i can make it in hfss eigenmode, but i have never used the feature before. I tried to find some tutorials but failed... Can anyone here help me ? Thanks in advance. Tomek
hfss v11 may tell you if your solution convergence or not
Dear all, I ran an hfss simulation and after 7 passes, it reached my convergence criteria. However, it could not run the frequency sweep (Fast sweep) due to out of memory. Is it possible to get the mesh after 6 passes? I am just wondering if using the mesh after 6 passes would help reduce the memory significantly. Would changing to interpo
Dear all, I notice several things in hfss. Please confirm when you ever noticed the same: 1. The convergence profile/curve is not the same when change the sweep method e.g. fast sweep or interpolation. Although, all other parameters remain the same. 2. Interpolation sweep works better over a broadband frequencies. thanks.
Hello, I just need to know the exact definition of (solution frequency) in hfss? hfss will optimize the mesh to reach convergence criteria at the solution frequency and eventually solve the field at that particular frequency only. When you choose "interpolation sweep", the rest of the frequencies are interpolated b
I done extensive comparison between the hfss (FEM) and MWS (FDTD). My antenna model was relatively (electrically) large. hfss used approx. 30GB of memory when solving (direct solver) and the MWS used approx 200M cells (50 hours of solving time) for the same problem. My feeling is that the MWS required for the calculation less time, since discret
I am simulating a structure in hfss and plotting some complex quantities defined as output variables. Plotting the real and imaginary parts I have jumps in the graphs such that if I could flip the part over I would get the output I am expecting. Does anybody ever had this problem before? How did you solve it? Thanks
Hello, does somebody know which mesh type is to chose in hfss for plane structures? And if I have a radiation box which mesh type is to select for this. I have read that for round structures with surface approximation the result will meet fast the convergence criterion. And to decide whether the mesh is good the optical look is important. Is
From the discussion the problem you are facing is not clear. kindly post your hfss model, after running the model the problem you are facing can be solved.
I have done such a comparison between IE3D and hfss with the same structure, and a good match is achieved to give u some confidence. I suggest u to improve the convergence condition used in hfss.
Hello I am using hfss for my PCB trace SI simulation. In my sweeps, the solver getting struck in one point at a particular interpolation error thinking that in that frequency convergence will occur. for example at freq 2.5 GHz where the interpolation error is 33%, the solver is thinking the convergence will occur at that frequency range (...)
Hi, I'm trying to simulate a waveguide diplexer using hfss. I found in some documents, that the solution frequency used during adaptive meshing of a filter should be inside the passband of that filter - otherwise the mesh is dense enough only near the ports. But how to do this when simulating a diplexer that has different passbands for each a
So, I have been using hfss to simulate resonating circuits for about a month now. However, I am starting to check my old calculations and I have come across some rather troubling issues. The main problem is that it seems running the same simulation multiple times will give me radically different results. The resonance will be off by up to 40% of
Hi, I recently modeled an UWB antenna in hfss. After fabrication there is big deviation in measured results as compared to the simulated ones even though they show the same trend. For example,measured S11,gain and radiation pattern results differ from the simulated ones. What are the tricks/tips to get simulated results as close as possible to
Why simulators like hfss and CST use (as a default) absolute convergence criterion not relative? I guess the last method could be more accurate because it for example can make difference between s11(n)=1, s11(n-1)=0.9 and s11(n)=0.2, s11(n-1)=0.1. In the first case relative error is 11% in the second - 200%, but absolute error is constant = 0.1. W
I read a post that was describing the frequency sweeps in hfss, and I noticed that some of the information was out-of-date. But the poster had good intentions :grin:, so this is a follow up with updated and correct information. Latest Release: hfss13.0.2. There are 3 frequency sweeps in hfss: Discrete, Fast, and Interpolating. [SIZE="4
Hi, In hfss, I have found that some settings affected significantly final results. If you were not to mind about simulation time, what values do you set to hfss analysis parameters. For example, Maximum number of passes = 50, Max. Delta S = 0.001, ect. Please suggest ... Thanks a lot :) DYL