Graphical determination of small signal hybrid parameter of bipolar junction transistor

Aim

Graphical determination of small signal hybrid parameter of bipolar junction transistor.

Apparatus Required:

Transistor kit, two voltmeter, two ammeters and connecting leads.

Theory:

In transistor representation, a mixed type of parameters called the hybrid parameters or h parameters equation are:

Vi = h₁₁I₁+h ₁₂ V ₂

I₂= h₂₁I ₁ +h ₂₂V₂

Where h ₁₁= V₁/I ₁V ₂=0; Called input impedance with o/p short circuited.

Its unit is ohm.

H ₂₁=I ₂/I ₁V₂=0;

Called forward transfer current gain with o/p short circuited.

It is dimensionless quantity.

Where h ₂₁= V₁/V ₂I = O; Called reverse transfer voltage ratio.

h₂₂= I₁/ V₂I= 0 Called o/p Admittance.

Procedure:

1. Connect the circuit as shown in fig. and switch the experiment kit.
2. First open the output terminal and supply 5V to input terminal. Measure o/p voltage and i/p current
3. Secondly, short the o/p terminal and supply 5V to input terminal. Measure I/P and O/P current using multimeter.
4. Calculate h ₁₁,h _12jh ₂₁,h ₂₂

Observation Table:

Result: H- parameters of two port network has been calculated and verified

Precautions:

1. Make the connections according to the circuit diagram. Power supply should be switched off.
2. Connections should be tight
3. Note the readings carefully.

Quiz:

Q1:What are h parameters of a transistor?

A1:The h parameter or the hybrid parameters of a transistor helps us to analyze the amplifying action of transistor for small signal .it is necessary for practical purposes. In generally there are four type of h parameter. These are : h ₁₁h ₁₂h ₂₁h ₂₂

Q2:What are h parameters of a transistor?

A2:The h parameter or the hybrid parameters of a transistor helps us to analyze the amplifying action of transistor for small signal .it is necessary for practical purposes. In generally there are four type of h parameter. These are : h ₁₁h ₁₂h ₂₁h ₂₂

Q3:What are benefits of H-parameter?

A3:Following are the advantages of h-parameters:

1. h-parameters are Real Numbers up to radio frequency
2. They are easy to measure
3. They can be determined from transistor static characteristic curves
4. They are convenient to use in circuit analysis and design
5. Easily convertible from one configuration to other
6. Readily supplied by manufacturers

Q4:H parameter operates in which frequency?

A4:Up to radio frequencies i.e 20-20khz

Q5:Which of the h-parameters corresponds to re in a common-base configuration?

A5:hib

Q6:Which of the following is referred to as the reverse transfer voltage ratio?

A6:hr

Q7:What is admittance?

A7:In electrical engineering, the admittance (Y) is a measure of how easily a circuit or device will allow a current to flow. It is defined as the inverse of the impedance (Z). The SI unit of admittance is the siemens (symbol S).