传输线理论（英文）TRANSMISSION LINE THEORY
I. The Transmission Line Model:
Consider the following repeating (uniform) sequence of "lumped" circuit elements:
Applying elementary circuit analysis to each node of such a "discrete" transmission line we may write a set of basic circuit equations. vn +1 (t) = vn ( t) R s in +1 (t ) L s in +1 ( t) = in (t ) Gp vn (t ) Cp d i ( t) dt n +1 d v ( t) dt n [ I-1a ] [ I-1b ]
The crucial matter is that the voltage and current vary both in time and space! To obtain a solution, we first deal with the time dependence by making use of the "phasor" concept -i.e. we replace the time dependent variables with their Fourier Transforms
+∞
vn (t) =
∞
∫ V (ω) exp[ j ω t] dω
n
+∞
and in ( t) =
∞
∫ I (ω) exp[ j ω t] dω
n
[ I-2]
or in the language of circuit analysis vn ……
