CST激励信号excitation signal

激励信号（excitation signal）是左侧导航树里面看到的高斯信号。这个激励信号就是上面这几种激励结构里所要传播的信号函数，包括高斯信号、方波信号、余弦信号等等。不明白它跟Waveguide Port, Plane Wave 和 Discrete Port是MWS里面实现激励的三种主要的方式有什么关系?怎么根据实际来选择呢?

首先，是要确定选择什么样的激励信号函数（比如高斯信号、方波信号还是余弦信号）还是要选择什么样的激励模式（波导端口、离散端口还是平面波）。
对于激励模式，CST帮助文件里有解释：
Waveguide Port：Waveguide ports represent a special kind of boundary condition of the calculation domain, enabling the stimulation as well as the absorption of energy. This kind of port simulates an infinitely long waveguide connected to the structure. The waveguide modes travel out of the structure toward the boundary planes thus leaving the computation domain with very low levels of reflections. ...... The strategies to properly define waveguide ports depend a bit on the type of the transmission line.
Discrete Port：discrete ports offers another possibility to feed the calculation domain with power. Discrete ports are mainly used to simulate lumped element sources inside the calculation domain. These ports are a good approximation for the source in the feeding point of antennas when calculating farfields. In some cases, these ports may also be used to terminate coaxial cables or microstrip lines. 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.
Plane Wave：The plane wave excitation source provides you the opportunity to simulate an incident wave from a source, located a large distance from the observed object. In combination with farfield monitors, the radar cross section (RCS) of a scatterer may be calculated. Note: In case of plane wave excitation onto an infinite periodic structure, the unit cell approach is recommended, which is accessible via the boundary dialog.
Nearfield Source 和 Farfield Source 与 Plane Wave Source一样，都是用来仿真场分布的。
而对于激励信号函数，高斯信号是默认激励函数。除非你的工程需要使用特定的信号系统，再考虑在Excitation Signal Library里面选择对应的函数，或者手动导入/创建自定义的函数。

真的好感动啊！谢谢！

请教，这些信号的幅值有多大呢?从哪里看出来啊

CST MWS帮助文件《Reference Value and Normalizing》。