[問題] 請問符號

[normanT (門中有心)]

因為非電機本科  所以在看論文的時候有些符號不知道是什麼東西

所以想再這邊請問一下 S11 (11是S的下標)是什麼意思？

在這邊給一下前後文

This section considers a simple interconnect example for
which the generation of a macromodel fails. We present the example
under the standpoint of the design engineer, who knows
the physical geometry of the interconnect and is required to
generate a SPICE-compatible model in order to carry out the
design. The structure is a three-conductor transmission line. Its
scattering matrix is first computed over a bandwidth of 4 GHz
using a commercial frequency-domain 3-D field solver. Then,
the various scattering matrix entries are processed by the very
popular and robust vector fitting (VF) algorithm [3] in order to
produce a lumped model for the structure. It is well known that
VF produces a model in poles-residues form, which is readily
synthesized into a SPICE netlist. It turns out that VF fails to
provide a reasonably accurate model. As an example, we report
in Fig. 1 the original return loss S11 and the corresponding
response of a rational model with 20 poles. Although the raw
data are quite smooth, the model is very inaccurate.

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◆ From: 61.227.129.111
→ normanT:fig. 1 上面是有兩條曲線 分別代表 S11的實部和虛部
→ normanT:縱軸沒單位  橫軸是頻率
推 youwin0125:S參數 指的是 input output的電壓波比
→ youwin0125:前面的指的是輸出port 後面的1指的是輸入port
→ youwin0125:所以S11就是 從port 1輸入 且從port輸出的 電壓波比例
→ youwin0125:就是反射多少電壓啦 ㄎㄎ 這是RF常用的參數
→ normanT:瞭解  感謝樓上～