Re: FEM or MoM (Ansoft)

actually, this disscussion was fun... And, I beleive we all disscussed the matter inside the boundaries of scientific ethics and respect

Man, I love disscussing...

Hi Jian -- I felt my comments were gentle, but you have indicated some sensitivity to them. Out of respect to you I will try to refrain from comments about IE3D directly, even though I would like to make positive comments where I think IE3D has strengths, as I did above and as other people do. I will continue to state my opinions about other tools as I think such information can be useful to designers, and the resulting discussions of such points can be very illuminating, and we can all learn a lot.

Hi, James: I thnk every vendor will be sensitive to competing vendors' public comments to this vendor. Just like one of our sale representiatives put a feature list of IE3D in a spreadsheet and put some other vendors' names on the spreadsheet for the evaluators. I think it is very reasoable for our sale representative to do so because it did not have any negative comments on other vendors. However, I was told that one vendor's attorney issued a letter to the sale representative and requested our sale representative to remove the vendor's name from the list. I am not sure whether Sonnet's attorney did that. At least, I know Sonnet's name was in the spreadsheet.

As a vendor, Zeland has been very careful not to comment publically on other competing products because we know other vendors will be senstive to it. This is natural Thanks!

Hi Jian -- I did not know about your spread sheet, but that is no problem. You are welcome at all times to say anything you want about Sonnet, accurate or not, publicly or privately. Does not matter. In fact, I strongly encourage you to discuss Sonnet with your customers as you see fit. If it is accurate, that is wonderful. All tools have weaknesses, and I think it is very important for customers to know what those weaknesses are. I try to tell customers what our weaknesses are, but if I don't, I would consider it a favor if you would. If we do not know both weaknesses and strengths of each tool, then we can not make good decisions.

I think the problem we see here might be cross-cultural. I am not familar with the many different Chinese cultures, but I do know that what in English we all call "face" (in Japanese it is called "kao") is very important in many Asian cultures. I think perhaps any comment I make about your software, no matter how mild, might threaten your kao. (This is just a guess.)

In American culture, often times frank discussion threatens kao. This is viewd as very bad in many Asian cultures. I think this might have something to do with your reaction to my comments (which I view as very gentle, but you felt was an attack).

In American, and many Western cultures, it is entirely acceptable to point out problems. Kao is of little or no concern. Discussion can be about problems with your competitors, or with the other political party, etc. Just watch the US evening news any night. Those who are unfamilar with American culture think we are a terrible people with many problems and crime and polution and slums everywhere. But when they visit, they find America is full of nice people, with little polution, little crime, and pleasant towns. That is because we take special effort to point out our own problems, sometimes that is all we talk about. And then that helps get rid of the problems.

While frank discussion like this threatens kao, it also makes us stronger. If we do not point out the problems, the necessary discussion does not take place, and we are weaker.

As for our company, if a competitor makes a true statement about us, even if it is a weakness, I will agree. If he makes a false statement that I find out about, I will point out why it is wrong and offer infomation to support my case. I do not send a lawyer and I do not get angry. If I were to get angry, I would lose. I do not want to lose, so I do not get angry.

The situation I do not want is false statements that I do not know about. Now I have no chance to provide data and information to show that the statement is false. This is a very bad situation. If people are afraid I will get angry, then they will not discuss any problems with me. But, they will secretly tell other people. Now I can not reply about incorrect opinions because I do not know about them. This situation must be avoided at all cost.

So, for anyone still reading this long posting, do not worry about my kao. If you have something to say about Sonnet, good or bad, please post it. (Several people have posted some very nice things in another thread. Thank you!) I will be very happy to hear it, good or bad, and you might start a most interesting discussion that we will both enjoy.

Now...what was it this thread was about anyway????

Apparently, there was a mistake with my simulation setup. Now, HFSS gives quite good results. I am very gratefull to asdfaaa for great help.

Hi, in a few words, the MoM is used when You are studying tipically a planar structure (like a microstrip filter/antenna/etc.) and an example of CAD is the AnSoft Designer. You can use the MoM in the case of Filar Antennas (like lambda/2 dipole or Marconian Antenna) too and an example of CAD is the 4NEC2.
MoM is a technique who is based on the inversion of a matrix. The method give direct the currents and by inversion of the matrix You can determine the Field.

The FEM instead is usually used to study 3D Structures (like Resonant Cavities or T-Magic) and determine direct the Field. This method requires the Specific about the Box, where the System under Analysis is located. Some CAD who use the FEM are the AnSoft HFSS, the FemLAB, tha ANSYS.

If you are interested on the subject, send me a private message, and I will reply to You teh material of my Lessons here at the Faculty of Telecommunication Engineering (University of Pisa).