[请教]ADS导入s2p算Z不正常

memsvip

ADS导入s2p，算Z不正常，但算S、Y正常
求解答，谢谢！

s2p文件节选如下： # Hz S dB R 50.0 !Frequency(Hz) S11_Amplitude(dB) S11_Phase(deg) S12_Amplitude(dB) S12_Phase(deg) S21_Amplitude(dB) S21_Phase(deg) S22_Amplitude(dB) S22_Phase(deg) 2450000000.0 -8.19301284061 -66.6262081256 -0.743470193348 22.9137918744 -0.743470193348 22.9137918744 -8.19301284061 -66.6262081256 2450025000.0 -8.19428653273 -66.6297592652 -0.743237543445 22.9102407348 -0.743237543445 22.9102407348 -8.19428653273 -66.6297592652 2450055000.0 -8.19586273398 -66.634152971 -0.742949748331 22.905847029 -0.742949748331 22.905847029 -8.19586273398 -66.634152971 2450095000.0 -8.19735851411 -66.6482880832 -0.742036324849 22.9017119168 -0.742036324849 22.9017119168 -8.19735851411 -66.6482880832 2450162000.0 -8.20077056582 -66.6577941426 -0.741414291214 22.8922058574 -0.741414291214 22.8922058574 -8.20077056582 -66.6577941426 2450461000.0 -8.21504828134 -66.7174597903 -0.73753979978 22.8525402097 -0.73753979978 22.8525402097 -8.21504828134 -66.7174597903

s2p.rar (210.17 KB, 下载次数: 9 )

2017-12-10 19:59 上传

点击文件名下载附件
s2p

memsvip

s2p文件节选如下：

# Hz S dB R 50.0
!Frequency(Hz) S11_Amplitude(dB) S11_Phase(deg) S12_Amplitude(dB) S12_Phase(deg) S21_Amplitude(dB) S21_Phase(deg) S22_Amplitude(dB) S22_Phase(deg)
2450000000.0 -8.19301284061 -66.6262081256 -0.743470193348 22.9137918744 -0.743470193348 22.9137918744 -8.19301284061 -66.6262081256
2450025000.0 -8.19428653273 -66.6297592652 -0.743237543445 22.9102407348 -0.743237543445 22.9102407348 -8.19428653273 -66.6297592652
2450055000.0 -8.19586273398 -66.634152971 -0.742949748331 22.905847029 -0.742949748331 22.905847029 -8.19586273398 -66.634152971
2450095000.0 -8.19735851411 -66.6482880832 -0.742036324849 22.9017119168 -0.742036324849 22.9017119168 -8.19735851411 -66.6482880832
2450162000.0 -8.20077056582 -66.6577941426 -0.741414291214 22.8922058574 -0.741414291214 22.8922058574 -8.20077056582 -66.6577941426
2450461000.0 -8.21504828134 -66.7174597903 -0.73753979978 22.8525402097 -0.73753979978 22.8525402097 -8.21504828134 -66.7174597903

memsvip

回复 1# memsvip

   Simulation / Synthesis Messages

Warning detected by hpeesofsim during SP analysis `SP1'.
The Z-parameter matrix does not exist because some or all of the Z-parameters are infinite. Setting all Z-parameters to zero.

Warning detected by hpeesofsim during SP analysis `SP1'.
While evaluating `SNP1.CMP1.All':
The provided data file doesn't cover the requested value(s) of `freq'. Therefore the required data was obtained from extrapolation.

Warning detected by hpeesofsim during SP analysis `SP1'.
While evaluating `SNP1.CMP1.Z[1]':
The provided data file doesn't cover the requested value(s) of `freq'. Therefore the required data was obtained from extrapolation.

telinsun

你的s2p file的S參數順序錯了, 應該是
Stim  Real (S11)  Imag(S11)  Real(S21)  Imag(S21)  Real(S12)  Imag(S12)  Real(S22)  Imag(S22)

memsvip

回复 4# telinsun

s2p 格式，可以是dB（dB-角，dB = 20*log10|幅值|），MA（幅值-角），RI（实部-虚部），角的单位是角度，不是弧度，缺省值是MA

I choose s11, s12, s21 & s22 data separately from s2p to make 4 new s1p files. S, Y & Z of 4 s1p files are all normal in ADS.


Why s2p to Z strange while s2p to Y normal?

memsvip

回复 4# telinsun


s2p中：  s11与s22相同， s12 与 s21相同

telinsun

你應該看一下S to Z table, 想想為什麼one port 可以, two port不行, 另外 ADS log就說了:
"The Z-parameter matrix does not exist because some or all of the Z-parameters are infinite"

http://www2.electron.frba.utn.ed ... version%20Table.pdf

呵呵1608

这个对测试应该影响不大，只是一个warning，原因应该是一些频点的Z参数计算不出来，他就将那些点的Z参数设置成0了。我试了一下2.451~2.460GHz间隔0.001GHz的仿真就没问题。

呵呵1608

射频电路设计第二版425页有各种参数矩阵之间对应的关系，其中Z矩阵用S参数计算时用到（1-S11）*(1-S22)-S12*S21，这个算式放到了分母上，用ADS的公式计算出这些值发现，凡是不能计算出Z的频点这个算式结果比其他频点小好几个数量级，几乎为0.所以Z对应的就是无穷大了（对ADS所允许的范围来说），就被置0了。

呵呵1608

q=(1-S11)*(1-S22)-S12*S21