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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
I am getting following error in one of my simulation- Fast sweep setup, process hf3d: poor convergence in computing port dispersion I require help to understand the following- 1)What is port dispersion? 2)How it effects the result? 3)How to correct it? Thanks Abhishek
Hi everyone, I met a problem when I use HFSS's Driven Terminal to simulate a structure. It is a warning, "Fast sweep setup, process hf3d: poor convergence in seeding data." My simulation setup is following, Solution Frequency: 14.25GHz - Adaptive Solutions Maximum Number of: 20 Maximum Delta S: 0.02 - Adaptive Options Maximum Refin
My work is on implicit FDTD method which allows time step (delta_t) above CFL limit. Implicit methods require one to solve a large sparse matrix. If delta_t is increased the the solution of this sparse matrix becomes slower. I can see this when I do the simulation with the implicit scheme. But my query is about mathematical explanation of what
My work is on implicit FDTD method which allows time step (delta_t) above CFL limit. Implicit methods require one to solve a large sparse matrix. If delta_t is increased the the solution of this sparse matrix becomes slower. I can see this when I do the simulation with the implicit scheme. But my query is about mathematical explanation of what h
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?
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 another.
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, 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
Hi everyone I really want to know if anybody came accross "checking for data convergence". I want my data passes to converge, how can I do it? Any ideas? I appreciate your help sally
Can any one tell some smart technics to solve convegence problems in DC or AC analysis. I know about these options STEPGMIN RELTOL ITL1 GMIN
Hi all I need help How to route through a copper poor in power pcb or blaze route ??
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
convergence of Stochastic Processes David Pollard Springer-Verlag format: djvu quality: very good Contents: Notation CHAPTER I Functionals on Stochastic Processes 1. Stochastic Processes as Random Functions Notes Problems CHAPTER II Uniform convergence of Empirical Measures 1. Uniformity and Consistency 2. Direct Appro if you use a dense mesh the result would be poorer than for initial meshes It's possible for resonanse structure calculation. Morever it's usual for this case bacause the convergence is not monotonic. Only for non-resonant structure dense mesh always corresponds better result. Also the result strongly depen
If a receiver has poor channel selectivity, the interferers that are out of the channel, will be amplified by the IF amplifier and will go into the demodulator, interfering with desired signal. In a digital system BER will be affected. You have to check the requirements for selectivity of your system (adjacent and alternate channel selectivity).
Anyone is using ultrasim for 5000+ transistor simulation? Do you encounter convergence problem in transient analysis? I have tried nearly all the option, sim_mode, trtol, speed .... and can't make it converge. It does running at the beginning but at a centain instant, the convergence problem will happen? any share is welcomed!
Hi! I need some information on how to solve convergence problems (time step too small) when I'm simulating power electronics systems which include analog parts, D latches and ABM parts. Also I have large currents and voltages to simulate at 70 kHz. I already read material from orcad's site, changed some settings in simulator and still have problem
Does anybody use ads to simulate? I have a convergence problem in simulate my circuit. I need help.
Does anyone use UltraSim for PLL simulation? DC convergence problem occurs when I use UltraSim to run a PLL simulation. DC simulation can converge with Spectre simulator but can't with UltraSim. How to solve this problem?
Thank you for replying !! noiseless, qqmz !! > noiseless I used idal switch. Nevertheless, there were some errors at certain input voltage values as follows. >Zero diagonal found in Jacobian at ... AND >The values for those nodes did not converce on the last Newton iteration are given below. >Also given is the mann
I'm a cad engineer but I have no more experience indeed, I met the question of timing convergence when do timing driven P&R with SE, which way should I think of and how to resilve it? Thanks for your help! Have a good day! Best Regards, Harryzhu
Hi coolrak: There is yet another interesting point to convergence, and that is how much the simulation error changes from pass to pass as you refine your descritizations. Often, we all assume that EM simulators provide monotonic error convergence. That is to say that as we make the descritizations smaller and smaller, the simulation result alw
Hi I'm working in a VCO design applying ELDO. As a autonomous circuit, VCO frequency is supposed by ELDO steady-state analysis, with a given initial frequency guess. Appliying a probe between two nodes, ELDO gets an oscillation frequency. How accuracy is it? Sometimes, oscillation steady-state analysis does not converge. How to fix this ?
CMOS process is cheaper comparable with others (GaAs, SiGe, etc). A CMOS PA can meet in some limits the same performances with competitors. Nobody wants to make a CMOS PA with poor performance. Just cheaper.
A model is built in ads and run. Under DC analysis is is converged, but under transient analysis it is nor converged. and the message below appeared, Pseudo transient does not converge Step limit exceeded. DC analysis converged with convergence mode = Newton-Raphson. Could someone tell me the possible reason and the posssible soluti
Hi. I have yet another problem with Pspice ERROR -- convergence problem in bias point calculation Last node voltages tried were: NODE VOLTAGE NODE VOLTAGE NODE VOLTAGE NODE VOLTAGE ( a0) 0.0000 ( a1) .7042 ( a2) 0.0000 ( a3) 0.0000 ( a4) 0.0000 ( a5) 0.0000
I am simulating a BGR using HSPICE. When i am simulating .op at any specified temprature using .temp,it is doing fine. But when i am trying to sweep the temprature, simulation is getting halt.I have tried with diffrent ranges of temprature,but the result is same.I tried with the different GMINDC and convergence =2,3 also .... I am getting surpr
can anyone tell me how to understand convergence control options? how to achieve convergence more quickly?anyone with some experience? Thanks
I'm trying to simulate a circuit in simulink. It was working fine upto a certain point. But after adding a mutual inducatnce element I get the following error. Error using ==> svd NaN or Inf prevents convergence. The circuit is complete and the error comes no matter what values for the mutual inductance are given. Anybody know where the pro
hi, i'm designing an integrator: OTA+capacitor when i simulate @ a differential input, i found out with the capacitive load, the differential output is so large that the Gm drops drastically, which means the linearity is poor. my questions are: 1). in general, should the output swing of OTA be limited? 2). how to simulate Gm? my method
I am learning about EM Simultor. And one of the big problem often comes is : The convergence problem. Can somebody help me to understand what is it? Thanks
when simulate analog circuits using Spectre, I often meet the convergence about spectre. for example, pss simulation, when the simulation time is 1us, the circuit is convergent; when the simulation time is 1.1us, the circuit is not convergent. what is the problem? Thanks!
Hi, recently I am doing the simulation of patch antenna by using CST. But when I using the waveguide port for coaxial cable, there are some convergence problems arising: The CST time-domain solver shows me the messege: " The calcuation seems to be unstable! Consider reducing the value for the stability factor in the solver specials options or r
Hello, I am working on a DC-DC converter. I am using cadence spectre for simulations. My transient analysis is simulating fine but the DC analysis is giving an error saying No DC Solution(No convergence) Can anybody help me how to overcome this. Thanks Kasi
When I run a simulation with hspice,it can't reach convergence. In the .lis file,the hspice diagnostic provided some nodes whose tol value are bigger than 1( the actual tol values are about 500). And I found those nodes are the power supply voltage sources and the nodes where there are input waves. how should I deal with them? Btw, I had ad
Hi, Can any body forward me some documents which describes how to improve the convergence of SPECTRE. thanks sarfraz
Hi, I have a peculiar case. I need some CMOS circuits which are facing convergence problems during Spectre simulation. Some generic blocks like Switching regulators do give some convergence problems during simulation. Can anybody give me the schematic of such circuits which are facing convergence problems. thanks sarfraz
the FOLLOWING is hspice hint: thanks!!!!!!!!!!!!! **diagnostic** dc convergence failure, resetting dcon option to 1 and retrying **diagnostic** dc convergence failure, resetting dcon option to 2 and retrying. no convergence with standard algorithm, trying damped pseudo-transient **warning** negative-mos conductance (...)
i am trying to calculate small signal AC gain of a circuit in H-spice but am not able to do it as spice is giving convergence error. Problem is not getting solved even by using PWL in power supply VCC as then it gives some absurd value of gain please help me in solving this convergence problem as it regularly gives head ache during simulations t
I want to know what happen when change .OPTIONS statement in HSPICE file to understand this problem. Anyone could give me an advice? in more details is the best. Because It's difficult to find "convergence problem" in very big circuit. Anyone met 'convergence" errors? help me pls
Consider the interactive process X(k+1) = 0.5 { X(k) + a/X(k)} where a >0 . Assuming that the process converges. To what does it converge ? What is the order of convergence?
Hi, I need your help to find a service manual for my Panasonic HD projection tv model # PT-47WX49. The standard convergence is not good enough for me. I saw a service tech clean my tv and he somehow pulled up a convergence screen that allowed for tuning that is not in the operation manual. I asked how he did this but for job security, he did no
Hey guys, I m finding this paper called poor man's explanation of Kalman Filters or How I stopped worrying and learned to love matrix inversion by du Plessis, R.M., 1967 Could u guys help me to find it? Please tell me where I can get this free. Thnx
Hi I am using an ideal op amp in inverting configuration as shown in figure (in pspice). The output fails to converge when i increase the value of feedback resistor (R2) above 14.5 KOhms The simulator gives the following error: ERROR -- convergence problem in transient analysis at Time = 708.8E-06 Time step = 582.1E-18, minimum allo
I have been using ELDO since I moved into electronic industry. I have heard that HSPICE has a lot of convergence problems. I have virtually seen NONE so far in using ELDO. Has anybody found a convergence problem in ELDO thus far?
Theory is this. I've got a poor batery, say 9V and its almost empty, but the voltage is still normal when unloaded. Say it's maximum current is 5 mA when shortcircuited. And I got a beeping device* that runs on everything from 3 volts and above that. This (whatever it is) draws 50mA in order to work. The idea is that the 9V battery will provide
When the circuit is not converged in spice or ADS, the nodeset command could be used to help to solve the problem. I want to know whether there is a similiar commnd in spectra. Thanks in advance!
I want to know about FMC (Fixed Mobile convergence).Can anybody help me?
Hello, I am looking for Coleman, T.F. and Y. Li, "On the convergence of Reflective Newton Methods for Large-Scale Nonlinear Minimization Subject to Bounds," Mathematical Programming, Vol. 67, Number 2, pp. 189-224, 1994. Anyone has it or can scan it ??? Thank you.