CST MWS中discrete端口和waveguide端口同时存在时S21不一致

However, due to the transmission between transmission lines of different geometric dimensions, reflections may occur that are much larger than those for the termination with waveguide ports. For lower frequencies (compared to the dimension of the discrete port), these reflections may be sufficiently small, such that these kinds of ports may also be used successfully for the S-parameter calculations of multipin connectors
——《Discrete Port Overview》
这两种端口是不同的，因而不一致很正常。

这个真不知道为什么

Lz解决问题了吗?解决之后来讲解一下啊 。

理解的不太明白，hfss 里面波端口和集中端口的s参数应该是互易的，为什么cst 不是呢?

这个不能以一个软件里“互易”作为判断依据，而要以物理/数值分析上这两者是否可以“互易”来判断。
CST的Help说的比较明白了，关键词是Reflection。