CONSTRUCTION OF A UHF ANTENNA (YAGI)

An antenna is a device to transmit and/or receive electromagnetic waves (often referred to as radio waves).  Antennas also radiate energy as possible because radiation is the primary function of the transmitting antenna.  This Yaghi antenna constructed can operate with the range of UHF cannels or band.  It has a high gain factor that can be in all channels such as UHF and VHF.  The Yagi antennas have better selectivity.

Aluminum rod of 0.86m was used in the construction of this antenna a 75  n_ coaxial cable, BNC plug, screws and support grip were used in the construction.  They were separately cut to required measurements.  One wire of the coaxial cable was joined to the dipole, the others to the parasites (directors and reflectors).  The spacing between the parasites and the dipole is 0.15 λ.  The constructed antenna (Yagi antenna) was tested with a television set and it received UHF and VHF transmitted by Enugu State Broadcasting Service and Nigeria Television Authority.

Due to the omni directionality of the Yagi antenna, it was tuned too particular transmission area to have a better selectivity.  The antenna has to be tuned to the transmission line to bring a clear reception.

 

Title page

Certification

Dedication

Acknowledgement

Abstract

Table of contents

Table of figures

1.1 Statement of problem

1.2 Aim and objective of the study

1.3 Justification of the study

1.4 Limitations of the study

2.1 Brief history of the antenna

2.2 Types of antenna

2.3 Functions of the antenna

2.4 Parameters of the antenna

3.1 Materials

3.2 Specification

3.3 Construction

3.4 Diagram

4.0 TESTING AND OBSERVATION

5.0 CONCLUSION AND RECOMMENDATION BIBLIOGRAPHY

FIGURE ONE - SPATIAL ARRANGEMENT OF THE 

ELEMENTS

FIGURE TWO - A DIPOLE ANTENNA AND IT’S RADIATION 

PATTERN

FIGURE THREE - COMPONENTS OF THE YAGI ANTENNA

FIGURE FOUR - THE CONSTRUCTED YAGI ANTENNA