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Convergence In Hfss

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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......
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
the simulation will terminate when either of these 2 criteria is met. if you set the maximum number of passes to 6 and the model does not converge within 6 passes the simulation will stop regardless. the maximum delta s defines the convergence criteria, if you use 0.02 it means that when the difference between two passes is less than 2% th
hi itaifrenkel posted a message below. it would help: hfss using convergence in order to get an accurate solution. After creating an initial mesh it starts doing adaptive passes until the desired error residual is achieved. In each stage it refines the mesh and resolves the problem. The resulting S-Matrix is compared to the previous one. The ma
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.
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 sim
Just a question on eigenmodes. I have noticed the following: when I simulate a cavity with a material with out losses I get the frequencies of the modes very fast, with high accuracy and with convergence in 2 3 steps.On the other hand when I replace with a material with losses, I can hardly get the convergence after 30 iterations or more and if I i
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
Yes, convergence is not an issue. I believe that the way the phase is handled by the simulator might be the problem.
Hello, I have been using CST MWS for the simulations of Infinite Reflectarrays and now I have started using Ansoft hfss comparisons or validation of my results. Can anyone help me in understanding WHat exactly is convergence? Also my total tetrahedra goes beyond 90k on 10 passes and when i set my deltaS=0.001, after 15 passes my system goes out
Fast sweep setup, process hf3d: Poor convergence in computing port dispersion. this is a warning i have some questions about: 1. what does it refer to? 2. what is "port dispersion"? 3. how can i control or determine the properties of this convergence? 4. to what level this error may effect my results?
hi, in order to be sure that there is no error with the meshing, you should check the convergence curve. If it tends toward a constant value (~0.02 for instance), there should be no errors. Are you sure about this that if convergence curve is straight linei.e it has a constant value then there will be no errors or differ
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
for most applications ΔS=0.02 is quite adequate. Decreasing the ΔS will result in a more complex mesh and more simulation time. Maximum number of passes of about 6 to 15 is enough. You can see the convergence data of your design by right clicking on the setup in project manager and selecting "convergence" from the pop-up menu. If it has
Increase the number of passes to 15 and see if they converge. none convergence implies faulty results. Regards Elchiquito
Well, could you give the schematic of your antenna ? If your S11 is too high perhaps you have wrongly design your lumped port ? Show the convergence of hfss, if the process hasn't converged the post data are wrong. Have you got warning after checking your entire design (see the validate icon of hfss) ?
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
hakunamatata shalom, Delta S is important but not the most important. You can easily check convergence and see how much each adaptation changes the error and decide for yourself which accuracy you need. Remember that some narrow bandwidth filters require a change in the default initial mesh settings. Lowpass filters require adaptation in a lo
check the convergence in matrix data whether it is converged first; try to reduce the convergence criteria and re-run the simulation again; the difference of simulated S11, what kind of difference is it? for example, whether all the resonance are still there? whether the resonant frequency shifted? If only the magnitude of resonace different, mos
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 (...)
I don't get everything, but I'll start to answer this anyway. I used ports some time ago, when I learned to handle hfss. The type of port impedance and the value must be chosen correctly. As far as I remenber, the help file or the handbook (pdf) includes a technical note on wave ports. This explaines how to set the ports correctly. Because a por
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
Itai Shalom, Thanks for the input. No particular reason for me using the driven terminal solution other than the fact that I saw it being used in an antenna simulation in one of the tutorials. Also, I want to find the impedance of the line I'm feeding through the coax. The convergence would give me the impedance of the coax, not the line, if I
Hello, I have set up an air box around my antenna and defined it as a radiation boundary. The box is distanced at a bit more than a quarter of the free space wavelength of the cenetr frequency from every side of the antenna (except the feeding side). The trouble is that when I increase the dimensions of the box, the antenna parameters (eg. S11) v
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, 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
Hi walaa, the meshing will definetly have an effect on your design. Restricting the mesh in certain sensitive regions of your design will usually improve the accuracy of your results, so long as its done correctly. One way you can check how good your mesh is, is by plotting the convergence of S11 (using adaptive pass instead of setup1). You shou
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 am facing problems with meshing in hfss for a waveguide filter design Can u suggest me any document of hfss inorder to setup the meshing and its convergence.. I can share my file with u ..if required. Thanks Venu
Hi, The boundary is too samll that couldn't convergence. Please make sure the space between antenna and boundary is more than 1/4 wave length. Thanks for your reply, as you see my boundary is just towards the +z direction and almost exactly lambda/4. Should I extend it to all directions for lambda/4 as well? And
This error is to let you know that you exceeded your RAM and avaliable swapping (since you are on 32 bit system, only 3GB accessible) Why are you converging so strongly? Track you quantities per adaptive pass as you likely are oversolving your simulation with such a high convergence have fun :)
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 (...)
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
There are four different design's that are mentioned in the tutorial,and there are some errors as well that have to be fixed in this tutorial coming to your question.convergence is The criteria of hfss is based on S-parameter at the ports. S-parameter is the integration of field intensity on the port surface. So, S-parameter is considered converge
The attached hfss file is for a half-wave dipole for 14.2 MHz. The dipole is only just over 1 m long, but is emmersed in water, so the relative permttivity is around 91, so it should resonate around 14.2 MHz or so, though perhaps a bit higher, as there is not a huge amount of water. The problem is, the mesh will not converge. It slowly converge
It beame only stable when meshing at 160GHz. I have a large discontinuity in my structure but I expected the adaptive meshing to be smart enough to get it. I think the way hfss does its convergence check is not efficient. It should check the actual field values instead of S parameters
hi :D in fact i have modified solver option not structure, by the way i'm not sure about your design solver convergence ,i believe that is the main problem, because when you add a non-assigned rectangular surface, design meshes change and so s-parameters change too! is n't? to prove my idea i ll upload a example design later regards red
If you first do the convergence analysis for a single frequency, the mesh used in the final pass is recorded. There is an option for the mesh used in the frequency sweeping. Choose "current mesh"(?), then the sweep will be done with the mesh recorded above.
You should use probably a more dense mesh to simulate such problem in Mom( cells per wavelength>30, edge mesh on). If you used adaptive meshing in hfss and the convergence criteria was reached und most of all, you have correctly modeled, the results of hfss will be more exact than that of MOM.
Hi Mirriyaz, I agree with what asdfaa has said. I had the same problems when I was simulating my antenna and after I increased the number of passes, it worked fine. Try that... Also like he said, you can look at the convergence to see how the meshing is coming along... Ananth.
Does hfss divide the model in to sevel regions? And in adaptive process, how did hfss know which sub region has the most error? the adaption sotppage condition is based on the convergence of S-parapemeters of the ports you defined. No matter how many subregions being generated, the integration of field component on the surfac
What should I set the convergence to and how many modes should I solve for? Also should I regenerate the mesh for each eigen-point or can I use the same mesh? Also what does converge on real-frequency only do? Shouldnt it alwasy be real? I set the convergency to 0.0001 so that it almost never reached, therefore the simu
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 (...)
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
That's why you need to put in the setup analysis: min convergence pass: 2