求问CST MWS系统部分尺寸差别太大时如何处理？

需要在一个横截面1X1m长20m的波导里插入一根长1dm的天线，直接模拟的话天线尺寸与波导相差太大，网格的最大尺寸比太大，计算极慢，请问大侠们怎么解决。本人新手，求说得详细一下，多谢！

或者如何设计一个球面波源，跳过天线的模拟过程

试试看subgridding吧。

1dm？1cm？可以直接用离散端口代替天线

我按照教程进行了局部网格的划分，选了subgridding，但是出了错如下，怎么查在哪儿出了错呀：
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.

做了个模型，其中有根天线尺寸特别小，划分了局部网格，选了subgridding，出了错如下，可能是哪里出了错啊？

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.

上传模型，请大神们指导，跪谢！

为了大神们看的方便，再上传一个有结果的：

我的模型在这里 能不能帮忙看下错在哪儿，多谢多谢！ 1

直接在1mX1m的面上加离散端口吗？出来的可以近似是球面波？