CST MWS怎么总是出现计算不稳定呢

这个以前论坛上讨论过，小编参考一下T求解器中的Electric shielding for all ports选项试试。
Solve->Time Domain Solver-> [Specials...]
Electric shielding for all ports: A perfectly shielding (PEC) frame surrounding each waveguide port region will be added. This option causes higher reflections at ports. Therefore, it should only be used if a calculation has become unstable.

楼上的正解哈，估计是结构比较复杂吧

也可能是一个internal port。