Page 330

CHAP. 13]

TWO-PORT NETWORKS

Z11 ¼ Z11;a þ Z11;b Z12 ¼ Z12;a þ Z12;b Z21 ¼ Z21;a þ Z21;b

319

ð31aÞ

Z22 ¼ Z22;a þ Z22;b or, in the matrix form, ½Z ¼ ½Za  þ ½Zb 

ð31bÞ

Parallel Connection Figure 13-13 shows a parallel connection of two-port networks a and b with short-circuit admittance parameters Ya and Yb . In this case, the Y-parameters are convenient to work with. The Y-parameters of the parallel connection are (see Problem 13.11): Y11 ¼ Y11;a þ Y11;b Y12 ¼ Y12;a þ Y12;b Y21 ¼ Y21;a þ Y21;b Y22 ¼ Y22;a þ Y22;b

ð32aÞ

or, in the matrix form ½Y ¼ ½Ya  þ ½Yb 

ð32bÞ

Fig. 13-13

Cascade Connection The cascade connection of two-port networks a and b is shown in Fig. 13-14. In this case the T-parameters are particularly convenient. The T-parameters of the cascade combination are

A ¼ Aa Ab þ Ba Cb B ¼ Aa Bb þ Ba Db C ¼ Ca Ab þ Da Cb

ð33aÞ

D ¼ Ca Bb þ Da Db

or, in the matrix form,

½T ¼ ½Ta ½Tb 

ð33bÞ

Mahmood_Nahvi_eBook_Schaum_s_Outlines_Theory_An