Active S参数和S参数之间有什么不同?
求各位大神赐教啊!
HFSS的帮助文件没有写么?
网上百度搜不到么?
网上找了半天没找到呢,帮助倒是没看,我去看看
还是没结果啊 大神们。求赐教啊
给你抄一段CST MWS的帮助文件:
However, in the case of simultaneous excitation several ports are stimulated at once, so it is not possible to apply the general S-Parameter definition. Now the incident and reflected spectra are given as so-called incident and reflected F-Parameters, all normalized to the spectrum of the reference signal. Furthermore, as an additional result and for a better analysis of the structure's behavior, the reflected spectra of all excited ports are normalized to their own incident spectra, respectively, providing so-called active S-Parameters. Since there might be more energy absorbed at a specific port than it itself has injected, the resulting curves could show active behaviour with values greater than one.
我不相信HFSS的帮助文件里没有。
我作证, HFSS的帮助文档里真没有,里面只有active Z和Z的定义。不过从active Z和Z的定义可以推测出active S和S的定义,所谓ACTIVE S也就是各个端口都有入射波的情况下,n端口的反射波与n端口的入射波的比,就是active Snn,不过要注意的是,对于N端口的器件,ACTIVE s只有N个,而不是N^2
具体表达方式回帖不好写,你可以在HFSS文档里搜索ACTIVE Z,有ACITVE Z的具体公式,然后你可以类比出ACTIVE S的公式
我2了,HFSS文档里有的是ACTIVE S的定义,需要自己类比出ACTIVE Z。
谢谢楼上的回答
active s is the reflection coefficient of one port when another port is excited...
for example, a 2 port system ,the total reflect wave at port 1 is S11*V1+S12*V2
the total reflection coefficient is total reflect wave at port 1 over total incident wave at port 1,then reflect coefficient is (S11*V1+S12*V2)/V1,which is the active S(1:1),
说因为传统S参数,每次只在一个端口进行激励,其他端口进行完全匹配。但是在HFSS多端口激励中,传统S参数不能用。只能用Active S param,这样可以考虑其他端口向这个端口传输的能量(即其他端口的耦合分量)。假设有K个端口激励。欲求ActiveSmm:
传统S参数和Active S param的关系ActiveSmm = a1/am*Sm1+a2/am*Sm2+a3/am*Sm3+...+am/am*Smm+....+ak/am*Smk.
其中ak为第K个端口入射波。am为第m个端口入射波,smm为传统S参数
好奇中,今天刚接触这个参数,因为发现active VSWR与VSWR的区别挺大的!