Loading [MathJax]/jax/output/HTML-CSS/jax.js
Module 7.1 Smith Chart
Z Chart
Y on Z Chart
Y Chart
Z
Y
Chart
0,0
zL
\left|\Gamma\right|
=
0,0
zL
yL on Z-Chart
0,0
yL
\left|\Gamma\right|
=
0,0
zL
參考阻抗
Z_{0}
(refernce impedance)
:
\Omega
參考導納
Y_{0}
(refernce admittance)
:
mS
負載阻抗
Z_{L}
=
+ j
\Omega
" =>Normalized impedance z:
+ j
負載導納
Y_{L}
=
+ j
mS
=> Normalized admittance y:
+ j
反射係數
\Gamma_{L}
:
\angle
°
( 顯示
\left|\Gamma\right|
)
(reflection coefficient) (
\Gamma_{L} = \left|\Gamma\right|\ * \angle \theta_{\Gamma}
)
電壓駐波比
VSWR
:
(voltage standing wave ratio)
Introduction:
藉由選擇不同的Chart去觀察:
負載阻抗
Z_{L}
負載導納
Y_{L}
反射係數
\Gamma_{L}
在Smith Chart上的位置和變化,以及
Z_{L}
、
Y_{L}
、
\Gamma_{L}
和
VSWR
的關係。
Parameters:
Load impedance:
Z_{L} = R_{L} + jX_{L}
Normalized impedance:
z = Z_{L} / Z_{0} = r + jx
Load admittance:
Y_{L} = G_{L} + jB_{L}
Normalized admittance:
y =Y_{L} / Y_{0} = g + jb
Reflection coefficient :
\Gamma_{L} = \left|\Gamma\right|\ \angle \theta_{\Gamma}
a.
\left|\Gamma\right|
:magnitude of
\Gamma_{L}, 0 \leqq \left|\Gamma\right|\ \leqq 1
b.
\theta_{\Gamma}
:phase of
\Gamma_{L}