HFSS激励频率设置问题

经常有这样的经验，比如设置激励频率为10GHz，扫频6-12GHz时，仿真6GHz的结果和设置激励频率为6GHz时6GHz的仿真结果差别很大，请教这是什么道理?
另外仿真时经常出现Mesh generation has failed的问题，改变模型尺寸之后就没有了，这又是怎么回事?有时候用HFSS10仿真有这个问题，换成HFSS11仿真就没有了。感觉非常奇怪。

这个问题我也疑惑过，后来问过ansoft的技术支持
简单归纳就是应该设置在resonance frequency上
邮件原文缩水版如下
ask：
I have one doubt when using HFSS.
I am simulating a 2.4GHz microstrip fed patch antenna.
For the same model, it will have different results if I use different “Analysis setup”.
The first setup with “solution frequency: 2.4GHz” “Maximum Delta S: 0.01”
The second setup with “solution frequency: 3GHz” “sweep frequency: discreet sweep ”covered 2.4GHz. “Maximum Delta S: 0.01”
Both setup converged, but S11 are different at 2.4GHz. (one is -5dB the other is -15dB)
Which result should be trusted?
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Reply：
The antenna is sensitive to the mesh. If you can send me the design, I can take a look for you. Usually the solution frequency should set to the resonance point.
Please mesh at 2.4GHz. I check the model, 2.4GHz should be good because it is extremely close to the resonance. If you use 3GHz, the mesh is not adapted at the solution frequency. Please do not mesh an antenna out of its resonance band.
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Ask：
Thanks your reply, I understand this case now.
One more question, what if the resonance frequency is unknown(or not obvious)?
For example,
1.how to setup the mesh for UWB antenna?(3-10GHz)
2.how to setup the mesh for dual-band antenna(2.4GHz, 5.2GHz)?
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Reply：
UWB: Use highest resonance frequency in the passband or resonance. If you want more accurate results, mesh using dependent setup. For example, there are 4 resonance points, 3GHz, 5GHz, 7GHz, 10GHz, solve each and adapt at each frequency. Make reuse the mesh of the 3GHz to solve 5GHz and so on.
Dual-band: same as above.

非常感谢！我最近在做螺旋天线仿真，因为同一个螺旋天线工作在轴向模和法向模时频率差别比较大，所以各种频率我都要试一试，结果就彻底晕菜了。
还有，Make reuse the mesh of the 3GHz to solve 5GHz是怎么操作的呢?我一直都是先清除前一个仿真结果，然后再改变频率重新仿真的，结果总是漫长的等待。

Make reuse the mesh of the 3GHz to solve
我理解就是setup设置在3GHz，sweep设置从3到5GHz
你可以设置多个setup和多个sweep来方便你计算，不需要每次都清除前面的结果