Two-Port Networks Chapter 19

19.1 Introduction A two-port Network is an electrical network with two separate ports for input and output. ch19 Two-Port Networks

19.2 Impedance Parameters ch19 Two-Port Networks

z11 = Open-circuit input impedance z12 = Open-circuit transfer impedance from port 1 to port 2 z21 = Open-circuit transfer impedance from port 2 to port 1 z22 = Open-circuit output impedance ch19 Two-Port Networks

Fig 19.3 ch19 Two-Port Networks

19.4 ch19 Two-Port Networks

Fig 19.5 ch19 Two-Port Networks

Fig 19.6 ch19 Two-Port Networks

Example 19.1 Determine the z parameters for the circuit in Fig. 19.7. ch19 Two-Port Networks

Example 19.1: PSpice To find Z parameters **Example 9.1 .Param Current_at_port2=1 **port2 = 0 : inject 0 A at port 2 ; 1st row **port2 = 1 : inject 1 A at port 2 ; 2nd row I1 0 1 DC {1-Current_at_port2} ********************************************* R1 1 1x 20 R2 1x 0 40 R3 1x 2 30 I2 0 2 DC {Current_at_port2} Vdummy 100 0 DC 1 .DC Vdummy 1 1 1 .STEP PARAM Current_at_port2 LIST 0 1 .PRINT DC V(1) V(2) .END We need to edit here for different circuits ch19 Two-Port Networks

ch19 Two-Port Networks

ch19 Two-Port Networks

ch19 Two-Port Networks

The Results z11 z12 z21 z22 3.000E+01 2.000E+01 2.000E+01 5.000E+01 ch19 Two-Port Networks

19.3 Admittance Parameters ch19 Two-Port Networks

y11 = Short-circuit input admittance y12 = Short-circuit transfer admittance from port 1 to port 2 y21 = Short-circuit transfer admittance from port 2 to port 1 y22 = Short-circuit output admittance ch19 Two-Port Networks

Fig 19.13 ch19 Two-Port Networks

Example 19.3 Obtain the y parameters for the  network shown in Fig. 19.14. ch19 Two-Port Networks

Example 19.3 ch19 Two-Port Networks

Example 19.3 ch19 Two-Port Networks

Example 19.3 To find y parameters **Example 19.3 .Param Voltage_at_port2=0 **port2 = 0 : apply 0 V at port 2 ; to find 1st row **port2 = 1 : apply 1 V at port 2 ; to find 2nd row V1 1x 0 DC {1-Voltage_at_port2} Vport1 1x 1 **************************************************** R1 1 0 4 R2 1 2 2 R3 2 0 8 Vport2 2x 2 V2 2x 0 DC {Voltage_at_port2} Vdummy 100 0 DC 1 .DC Vdummy 1 1 1 .STEP PARAM Voltage_at_port2 LIST 0 1 .PRINT DC I(Vport1) I(Vport2) .END We just need to edit here for different networks. ch19 Two-Port Networks

ch19 Two-Port Networks

ch19 Two-Port Networks

ch19 Two-Port Networks

The Results are y11 y12 y21 y22 7.500E-01 -5.000E-01 ch19 Two-Port Networks

Example 19.4 Determine the y parameters for the T network shown in Fig. 19.17. ch19 Two-Port Networks

Example 19.4 ch19 Two-Port Networks

Example 19.4 ch19 Two-Port Networks

Example 19.4 ch19 Two-Port Networks

Example 19.4 ch19 Two-Port Networks

PSpice To find y parameters **Example 19.3 .Param Voltage_at_port2=0 **port2 = 0 : apply 0 V at port 2 ; to find 1st row **port2 = 1 : apply 1 V at port 2 ; to find 2nd row V1 1xx 0 DC {1-Voltage_at_port2} Vport1 1xx 1 **************************************************** R1 1 1x 8 R2 1x 0 2 R3 1x 2 4 F1 1x 2 Vport1 2 Vport2 2xx 2 V2 2xx 0 DC {Voltage_at_port2} Vdummy 100 0 DC 1 .DC Vdummy 1 1 1 .STEP PARAM Voltage_at_port2 LIST 0 1 .PRINT DC I(Vport1) I(Vport2) .END ch19 Two-Port Networks

ch19 Two-Port Networks

ch19 Two-Port Networks

ch19 Two-Port Networks

The Results are y11 y12 y21 y22 1.500E-01 -2.500E-01 ch19 Two-Port Networks

19.4 Hybrid Parameters ch19 Two-Port Networks

h11 = Short-circuit input impedance h12 = Open-circuit reverse voltage gain h21 = Short-circuit forward current gain h22 = Open-circuit output admittance ch19 Two-Port Networks

Fig 19.20 ch19 Two-Port Networks

Example 19.5 Find the hybrid parameters for the two-port network of . 19.22. ch19 Two-Port Networks

Example 19.5 ch19 Two-Port Networks

Example 19.5 ch19 Two-Port Networks

Fig 19.31 ch19 Two-Port Networks

a = Open-circuit voltage gain b = Negative short-circuit transfer impedance c = Open-circuit transfer admittance d = Negative short-circuit current gain ch19 Two-Port Networks

Example 19.8 Find the transmission parameters for the two-port network in Fig. 19.32 ch19 Two-Port Networks

Example 19.8 ch19 Two-Port Networks

Example 19.8 ch19 Two-Port Networks

19.6 Relationships Between Parameters ch19 Two-Port Networks

Example 19.10 Find [z] and [g] of a two-port network if Solution: ch19 Two-Port Networks

Example 19.10 ch19 Two-Port Networks

19.7 Interconnection of Networks ch19 Two-Port Networks

Example 19.12 Evaluate V2/V1 in the circuit in Fig. 19.42. ch19 Two-Port Networks

Example 19.12 ch19 Two-Port Networks

Example 19.12 ch19 Two-Port Networks

Example 19.13 Find the y parameters of the two-port in Fig. 19.44. ch19 Two-Port Networks

Example 19.14 Find the transmission parameters for the circuit in Fig. 19.46. ch19 Two-Port Networks