YAGI-UDA ARRAYANTENNA

PRESENTED BY -RAKESH KUMAR SINGH

SUSHIL KUMAR KAUSHIK

WASEEM AHMAD

POINTS OF DISCUSSION :-INTRODUCTIONTYPES OF ANTENNAWHY YAGI-UDA ANTENNA??????HISTORY OF YAGI-UDA ANTENNAYAGI-UDA ANTENNAGEOMETRYCHARACTERISTICS OF YAGI-UDARADIATION PATTERNAPPLICATON

INTRODUCTIONAn antenna (or aerial) is a transducer that transmits or

receives electromagnetic waves. In other words, antennas convert electromagnetic radiation into electrical current.

Antennas generally deal in the transmission and reception of radio waves, and are a necessary part of all radio equipment.

Antennas are used in systems such as radio and television broadcasting, point-to-point radio communication, wireless LAN, cell phones, radar, and spacecraft communication.

Antennas are most commonly employed in air or outer space, but can also be operated under water or even through soil and rock at certain frequencies for short distances.

TYPES OF ANTENNASLOOP ANTENNA

FERITE CORE ANTENNA

FOLDED DIPOLE ANTENNA

YAGI-UDA ANTENNA

WHY YAGI-UDA ANTENNA

It is simple to construct.It has a high gain, typically greater than 10dB.These antennas typically operate in the HF to UHF bands

(about 3 MHz to 3 GHz), frequently employed as TV/FM antennas.

Lightweight Low costUnidirectional beam (front-to-back ratio) Increased directivity over other simple wire antennas. It is widely used as a TV reception antenna and achieves

fairly good directivity with such a simple structure.

YAGI-UDA HISTORYThe Yagi-Uda array was invented in 1926 by Shintaro Uda of

Tohoku Imperial University, Japan, with a lesser role played by his colleague Hidetsugu Yagi.

The work was originally done by Shintaro Uda, but published in Japanese.

The work was presented for the first time in English by Yagi (who was either Uda's professor or colleague) who went to America and gave the first English talks on the antenna, which led to its widespread use.

Hence, even though the antenna is often called a Yagi antenna, Uda probably invented it.

It’s one of the most famous and used directional parasitic antennas.

Professor Yagi with a Yagi-Uda antenna

YAGI-UDA ANTENNA In a Yagi antenna, there is at least one driven

element, one reflector element, and usually one or more director elements.

The Yagi antenna is also known as a linear end-fire antenna or a Yagi-Uda array, has a linear array of parallel dipoles.

Yagi antennas are directional and designed for long distance communication.

GEOMETRY

CHARACTERISTICSRadiation pattern

3-dB beamwidths

Front-to-back ratio

Directivity

Input impedance

Gain

Radiation Pattern: E-plane

Radiation Pattern: H-plane

3-D Radiation Pattern

FRONT-TO-BACK RATIOThe front-to-back ratio:is

the ratio of the maximum directivity in the forward direction to that in the back direction.

3-dB BEAMWIDTHBeamwidth is a measurement

used to describe directional antennas.

Beamwidth is sometimes called half-power beamwidth.

Half-power beamwidth is the total width in degrees of the main radiation lobe, at the angle where the radiated power has fallen below that on the centerline of the lobe, by 3 dB (half-power).

GAIN

APPLICATIONDesigned for long distance communication.Frequently employed as TV/FM antennas.Used in systems such as radio and television broadcasting. Point-to-Point radio communication.