边界条件和激励源2

我现了模型矩形波导和介质层，边界条件设置为y方向为E，x方向为H，z方向为open，背景材料为真空，有两个警告：at least one propagating mod at port 1 is not considered in time domain calculation！it might be better to increase the number of modes at port 1.
some higher propagating modes at port 2 are not considered in time domain calculation.this possibly leads to an inaccurate enery balance.consider to reduce the port size or decrease the upper frequency limit. 怎么回事?

对于Empty Waveguide，CST帮助文件是这么说的：
CST MICROWAVE STUDIO® solvers generally allow using more than just the fundamental mode in the waveguide port. This becomes especially important when higher order modes need to be taken into account.
The number of propagating modes vary due to the chosen frequency range. As a rule, the number of modes to be considered at a waveguide port should at least be the number of propagating modes, because unconsidered modes will be reflected by the port operator.

谢谢了，能用汉语说说吗?

这点儿英语应该不难理解吧……
对于有截至频率的模型，仿真频率很宽或者端口尺寸很大时，就有必要仿真多个模式，否则多余的能量会被端口反射回去，降低仿真的准确性。

有点不懂哎

at least one propagating mod at port 1 is not considered in time domain calculation！it might be better to increase the number of modes at port 1.
今天我也遇到了这个问题，我把波端口改小了就不报错了
波导口大了，截止频率就低了，如果设置的小一点截止频率就高了，就不用“decrease the upper frequency limit”，不知道是不是这么回事

谢谢指教，明白了。是不是，就是出现了高阶模态?

看不懂啊。

呵呵呵呵呵

我也出现同样问题，求解some higher order propagating modes at part 1 are not considered in time domain calculation,仿真结果没s参量数据?

频率改小就好了，但我要高频结果?