Lec 1. Two-Port Circuit Mr.Mohamed Elshaikh

What today?? ● Introduction ● The concept of two-port circuit ● The terminal equations ● Two-port parameters (Z, Y, ABCD, H, G) ● Relationships among the two-port parameters.

Introduction ● TKT419 Electric Circuits II ● 3 credits ● Lectures and Tutorial.. ● Assessment: – 4 tutorials (20%) – 2 tests (20%) – Final exam(60%) ● 4 weeks ( 12 hours each)

Contents: ● Topics: – Two-port circuit – Laplace Transforms – Frequency reesponse in AC circuit – Fourier Series – Fourier Transforms ● Textbook: – Electric Circuits, James W. Nilsson and Susan A. Riedel, Prentice Hall

The concepts of two-port circuit ● Two-port circuit is a method of analyzing some electrical System ● Systems are represented as a box with input and output (port or terminals) – Terminal pairs represents (I/O) of the signals

Example 1 ● Calculate the equivalent r for both ports....

Two-port analysis ● Relating the current and voltage between two ports ● The system must be in s- domain ● For purely resistive networks (resistive circuits) ● Sinusoidal steady-state need to be converted to s- domain first

Cont.. ● Uses set of equations to relate current and voltage. ● Two-port aims to describe the network by set of two equations. ● There are six different sets of equation. ● Which are:

Z Y Tran smis sion b h g Terminal equations

Calculating Z parameters IMPEDANCE PARAMETERS

Example ● Find z parameter for the below circuit:

Solutions: ● When port 2 open-circuit, I 2 =0 so,

● When I 2 =0, thus V 2

Now, when I 1 =0,so

● When port 1 open-circuit, I 1 =0, so:

ADMITTANCE PARAMETERS y parameters

a parameters

b parameters a and b parameters are called transmission parameters

INVERSE HYBRID PARAMETERS g parameters

Example ● Find y,g, and h parameters for the circuit bellow:

TWO-PORT NETWORK ● Terminal equations ● Two-port parameters ● Relationships between parameters ● Analysis of terminated two-port circuit ● Interconnected two-port circuits

Relationship between parameters ● Z and Y Then:

Z parameters

RELATIONSHIPS BETWEEN PARAMETERS

Compare these two above equations:

Find z parameters as functions of a parameters

Therefore,

RECIPROCAL TWO-PORT CIRCUITS ● If a two-port circuit is reciprocal, the following relationships exist among port parameters:

Symmetric of a reciprocal two-port circuits ● Following relationships exist among port parameters:

Y parameters

Problem 1. ● Find z parameters for. ● Use the result above to calculate y parameters.

Circuits

Problem

Q and A