Different types of antenna by shakir

DIFFERENT TYPES OF ANTENNA

Presentator SHAKIR HUSSAIN

Table of Content

Horn Antenna Slot Antenna MicroStrip Or Patch Antenna Quad-Helix Antenna for Telemetry Notch Antenna

HORN ANTENNA

What is Horn Antenna ? A horn antenna  is an antenna that

consists of a flaring metal waveguide shaped like a horn to direct radio waves in a beam.

Horn Antenna as termination of waveguide

Waveguide terminated with horn antenna radiates effectively than open ended rectangular waveguide.

Open ended rectangular waveguide

Horn Antenna as termination of waveguide

HORN ANTENNA

A horn antenna is used to transmit radio waves from a waveguide (a metal pipe used to carry radio waves) out into space, or collect radio waves into a waveguide for reception

Horns are widely used as antennas at UHF and microwave frequencies, above 300 MHz.

Horn Antenna

Radiation Pattern

Types of Horn AntennaPyramidal horn – a horn antenna with the horn in the shape of a four-sided pyramid, with a rectangular cross section. They are a common type, used with rectangular waveguides, and radiate linearly polarized radio wavessectoral horn – A pyramidal horn with only one pair of sides flared and the other pair parallel. Which is narrow in the plane of the flared sides, but wide in the plane of the narrow sides

E-pane horn (b) – A sectoral horn flared in the direction of the electric or E-field in the waveguide.H-plane horn (c) – A sectoral horn flared in the direction of the magnetic or H-field in the waveguide.Conical horn (d)Exponential horn

Horn Antenna

Why it is use ? It has high antenna gain, which can

range up to 25 dB in some cases, with 10-20 dB being typical.

It is used as feeders ( feed horns) for larger antenna structures such as parabolic antennas.

And as directive antennas for such devices as radar guns,  and microwave radiometers.

Horn antenna as feed horn

SLOT ANTENNA

A slot antenna consists of a metal surface, usually a flat plate, with a hole or slot cut out.

Slot antennas are used typically at frequencies between 300 MHz and 24 GHz.

the slot radiates electromagnetic waves in similar way to a dipole antenna.

SLOT ANTENNA

Consider an infinite conducting sheet, with a rectangular slot cut out of dimensions a and b, as shown in Figure.

If we can excite some reasonable fields in the slot (often called the aperture), we have a slot antenna.

SLOT ANTENNA Applications

  Slot antennas are widely used in radar antennas

 In sector antennas used for cell phone base stations.

A slot antenna's main advantages are its size, design simplicity

PATCH OR MICROSTRIP ANTENNA A patch antenna (also known as a

microstrip antenna) is a type of radio antenna , which can be mounted on a flat surface.

 It consists of a flat rectangular sheet or "patch" of metal, mounted over a larger sheet of metal called a ground plane.

MICROSTRIP OR PATCH ANTENNA

Microstrip or patch antennas are becoming increasingly useful because they can be printed directly onto a circuit board.

Microstrip antennas are becoming very widespread within the mobile phone market. Patch antennas are low cost, and are easily fabricated

MicroStrip OR Patch Antenna

Top View of Patch Antenna Side view of Patch Antenna

Radiation pattern of a simple square patch

Quad Helix Antenna For Telemtry A Quad helix Antenna is simply type

of helix(often called helical) antenna. In this four helix antennas are built

toghether on a conducting material. There are two modes in which helical

antennas operate Normal mode and Axial mode.

Quad Helix Antenna For Telemtry In normal mode the dimension of

helix less than wavelength. In Axial mode the dimension of helix

is comparable to wavelength. These helix antennas are referred to

as axial-mode helical antennas. They are used to send and recieve

the measurements from a remote area.

These Antennas work on high frequencies ranging from VHF up to microwave.

The antenna produces radio waves with circular polarisation.

circular polarisation

Notch Antenna

Notch Antenna is created from the slot antenna when slot antenna is cut down from the middle then it works as slot antenna.

Microwave antenna in which the radiation pattern is determined by the size and shape of a notch or slot in a radiating surface. 

NOTCH ANTENNA

Questions ???