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80 Threads found on Hfss Convergence
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
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?
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......
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
Hii All, Firstly thanks for the timely advices given to me by you'll, I could manage to resonate my antenna at the required Frequnecy of 10GHz, but now I have a new problem, my design runs smoothly for single frequency with the Airbox Height of lambda/4 (Approx 8mm) but when I try to run it for a sweep (from 7 to 11GHz) everytime its giving me
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 am new on hfss. I couldn't get the exact solution for RCS of a dielectric sphere(relative permittivity 4, cond = 0) using hfss V. 9.0. I am plotting RCS vs. theta. i used RADIATION as BOUNDARY CONDITION, and plane wave excitation. Should i use different BC? Would appreciate any suggestions. thanks sar5
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 !
Hi Guys Sorry for late reply but I haven't been using hfss for a long time. First of all it was optimized for high frequencies, so 64 MHz is too low. Recently I heard that they made modifications for lower frequencies. Anyways, ideally all should give the same results. I would check the setup first, lumped elements are tricky. If everything looks o
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.
Hi, guys. I have a question about hfss eigen-analysis convergence. For my analyzed structure, since I used Master-Slave boundary condition, it seems the frequency convergence is pretty poor. Some time it reaches theoretical value in one pass but divergence to a weired number in the next one.... So are there any good methods to (...)
please tell me whether its necessary that every solution should converge somewhere when using hfss9.2 normally i just give the solution setup then sweep with some step size ........and then validate it and simply run and note the results..... i don't go in RESULTS/SOLUTION DATA/convergence and check whether the solution gets converged somew
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
I simulate a 2-port transition,but there is something wrong with S21 of that modal: I set 8 passes , the first pass and the secord pass:S21 is large,about -10dvB. when the third pass overd,the value of S21 is -1.3dB,which is good for transition. but from the pass 4 to pass 8. the S21 became larger and larger .from -2.6dB to -7dB I can not under
Hello all, I am learning how to use hfss to simulate the radiation pattern of antennas. As a first step, I created a model of a half-wavelength dipole. I tried to verify the simulation agrees with the theoretical value to check if the simulation is correct or not. I plotted the radiation pattern and it has a donut-like 3-d pattern as expected. H
Hey everyone, I still haven't found a solution for the problem.. I'm sure there's got to be somebody (of all the hfss users we've got) who knows how to do this!! Ananth.
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
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?
Hi all! I am very new in the hfss field, and I have one question. I wonder why sometimes the solution does not converge even if the maximum number of adaptive passes is not reached yet. Thanks for your answers. Bye
hi, how do i make comparision between hfss and Microwave CST (Performance-wise) thanks in advance
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
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
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
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.
Hi guys, I have a problem with a simulation. The solution converges succesfully, but the results are not the waited. If I use a really low convergence condition, I get good results (not always). Have you ever seen that problem? I think maybe there is something wrong in the model, and it causes errors if the mesh is enough fine. How do you se
I've simulated an RFID tag antenna by both ie3d and hfss. (The antenna is posted by K. V. Seshagiri Rao, in the paper "Antenna Design for UHF RFID Tags A Review and a Practical Application".) But there are big differences in the results. In ie3d, the impedance at 875Mhz is about 50+j420.(close to the result in the paper) While in hfss it's abou
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
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?