求問CST MWS系統部分尺寸差別太大時如何處理？

需要在一個橫截面1X1m長20m的波導里插入一根長1dm的天線，直接模擬的話天線尺寸與波導相差太大，網格的最大尺寸比太大，計算極慢，請問大俠們怎么解決。本人新手，求說得詳細一下，多謝！

或者如何設計一個球面波源，跳過天線的模擬過程

試試看subgridding吧。

1dm？1cm？可以直接用離散端口代替天線

我按照教程進行了局部網格的劃分，選了subgridding，但是出了錯如下，怎么查在哪兒出了錯呀：
Subgrid mesh generation
Local mesh settings overlap for the shapes "single dipole/PEC:Driven Element" and "component1:solid2".
Using settings of shape "single dipole/PEC:Driven Element" within overlaping areas
Starting adaptive port meshing.
Mode calculation for port 2:
At least one propagating mode at port 2 is not considered in the time domain calculation! (At least one mode shares the same beta with considered mode(s) -> degeneration).It might be better to increase the number of modes at port 2. More...
Pass 1 successfully completed.
Adaptive port meshing finished.
Matrix computation (PBA)
Hexahedral mesher terminated abnormally.
Error in calculating solver matrix
Solver run aborted.
2 warnings occurred.

做了個模型，其中有根天線尺寸特別小，劃分了局部網格，選了subgridding，出了錯如下，可能是哪里出了錯啊？

Subgrid mesh generation
Local mesh settings overlap for the shapes "single dipole/PEC:Driven Element" and "component1:solid2".
Using settings of shape "single dipole/PEC:Driven Element" within overlaping areas
Starting adaptive port meshing.
Mode calculation for port 2:
At least one propagating mode at port 2 is not considered in the time domain calculation! (At least one mode shares the same beta with considered mode(s) -> degeneration).It might be better to increase the number of modes at port 2. More...
Pass 1 successfully completed.
Adaptive port meshing finished.
Matrix computation (PBA)
Hexahedral mesher terminated abnormally.
Error in calculating solver matrix
Solver run aborted.
2 warnings occurred.

上傳模型，請大神們指導，跪謝！

為了大神們看的方便，再上傳一個有結果的：

我的模型在這里 能不能幫忙看下錯在哪兒，多謝多謝！ 1

直接在1mX1m的面上加離散端口嗎？出來的可以近似是球面波？