标题: HFSS wave port 和 lumped port 的区别 [打印本页] 作者: admin 时间: 2014-10-11 17:23 标题: HFSS wave port 和 lumped port 的区别 <div class="content"> lumped port的激励以电压或电流的形式,加在一个点或单元上。
With wave-port=> the excitation is so-called eigen-wave, such as the quasi-tem wave supported by a microstrip line. It applies over a cross-sectional area.
而wave-port的激励称做本征波,比如微带线馈源提供的准TEM波,它加在一个横截面(剖面)上。
voltage is scalar, wave is vector by nature, hence there are substantial difference between the two. So use waveport whenever possible, because "simulation of wave phenomenon" is what HFSS is designed for. And compare with the "correct" measurement whenever possible (i.e. measure "wave", not simply "voltage")。
Why lumped port is there? It is easy to applied and people found that good/reasonable results can be obtained. Why? if the frequency is low enough or the excitation is applied at sufficiently small area, then the "wave" can be described by some "voltage" or "current", which must be "measured"/"calculated"/de-embedded/etc in the correct manner.
那为什么还要使用lumped port呢,这是由于lumped port激励的添加简单,并且可获得良好的结果。如果频率很低或者激励加在足够小的区域上,“波”就可以用“电压”或“电流”来描述,必须用正确地方式测量、计算。
if the excitation can be applied on some locally uniform region=>waveport,
if geometry/material discontinuities are near/closer to the point of excitation=>lumped port might be the only way.
另外,如果激励可以加在某些局部均匀分布的区域,应该采用waveport,如果激励点附近存在几何或材料上的不连续区,lumped port可能就是唯一选择了。
外部端口用wave port 内部端口用lumped port。
Wave port:是用Ansoft制作的一个电磁系统与外界进行能量交换的窗口,它能够到端口的S参数。它是一种典型的传输线型端口,它经常用来设置波导口和同 轴线的输出输入端口。它要设置在整个辐射框(吸收边界)的外面,如果在辐射框(吸收边界)内使用这种源的设置,就必须在端口的外边画一反射体(金属底座) 以此来确定波的传播方向。
Lamped Gap Sources同Wave port源的很相似,但Lumped Gap Sources一般设置为电磁系统的内部端口,它可自定义端口的阻抗。它可以用于微带线、波导及平行双导线等电磁系统源的设置,在设置Lamped Gap Sources时应注意两点:
1.用户定义的端口阻抗不能为零或负数,
2.此端口只允许单模传输。另外,还必须设置积分线。它的设置和Wave Port基本一致,只是Lumped Gap Sources需要设置阻抗和电抗。
wave port 端口不会产生任何反射,相当于匹配负载,而lump端口,指的是端口以集中元件代替,如果器阻抗值不等于连接的传输线,当然端口本身就引起反射.
微带线和差分线应该用waveport