清华考研 - 电路原理课件 - 第16章 - - 二端口网络

也可通过列端口电压、电流

关系得到参数方程 I1

U 1?? Z1 I1??? Z 3 I2?? U 2

Z1

U 2??? Z 3 I2 ??I2 Z 2

+ U 1

Z3

I2

Z2

+ U 2

-

-

将 I1代入第一式并经整理，可得

1?? (1?? Z 1 )U 2???U ( Z 1?? Z 3?? Z 1 Z 3 )I Z 2 Z 2

T11

2

也可求得

1?? 1 U 2???I (1?? Z 3 )I 2

Z 2 Z 2

Z2 = 1 / T21

Z1 = (T11 -1) / T21 Z3 = (T22 -1) / T21

T21

T22

返回目录

16.4

二端口的联接

一、级联（ cascade connection ）（链联）

I1

I1??

I2??T

I1???

I2???

I2

+ +

T???

+ +

T????

+

+ -

-

-

-

-

U-

2

设

[T?]???? T11??T12????[T???]?????????????T11?? T12????? ?T??21

??

?T?????21 T22???

即

?U??? 1????T11

T12?????????????

U 2??????? I

?????? ?U?????? 1????T?11? T12???? U 2????

1????T21 ??

?????

?

I1

I1??

I2??

T

+ -

I1???

+ -

I2???

I2

+ -

+

T???

T????

+ +

- - -

I1

+ - 得

I2??

T

?? I2??I2 T???

+ -

T????

+

-

???U 1???????????????T11 T12???? U ????????????2????T11

???? I 1????T21 T22?????? I 2????T21

T12?????T11?? T12??????

????????????????

?? 1????T11 ?U????T21 ? I 1???得 结论

T12?????T11???T12?????? U 2???

????????????

T?? T?? T????

级联后所得复合二端口（ composite two-port） T参

数矩阵等于级联的二端口T参数矩阵相乘。上述结论可推 广到n个二端口级联的关系。

T1

T=[T1][T2] …. [Tn]

T2

... ...

Tn