ANTENNA
Sai Info solution provide the Project
Development & Training. We Develop Project for BE/ME/PHDIn radio, an antenna is
the interface between radio waves propagating through space and
electric currents moving in metal conductors, used with a transmitter or receiver. In transmission,
a radio transmitter supplies an electric current to the antenna's terminals,
and the antenna radiates the energy from the current as electromagnetic
waves (radio waves). In reception, an antenna intercepts some of the
power of an electromagnetic wave in order to produce an electric current at its
terminals, that is applied to a receiver to be amplified. Antennas are
essential components of all radio equipment, and are used in radio
broadcasting, broadcast television, two-way radio, communications
receivers, radar, cell phones, satellite communications and
other devices. An antenna is an array of conductors (elements),
electrically connected to the receiver or transmitter. During transmission, the
oscillating current applied to the antenna by a transmitter creates an
oscillating electric field and magnetic field around the
antenna elements. These time-varying fields radiate energy away from the
antenna into space as a moving transverse electromagnetic field
wave. Conversely, during reception, the oscillating electric and magnetic
fields of an incoming radio wave exert force on the electrons in the antenna
elements, causing them to move back and forth, creating oscillating currents in
the antenna. Antennas can be designed to transmit and receive radio waves in
all horizontal directions equally (omnidirectional antennas), or preferentially
in a particular direction (directional or high gain antennas).
An antenna may include parasitic elements, parabolic reflectors or horns,
which serve to direct the radio waves into a beam or other desired radiation
pattern. The first antennas were built in 1888 by German physicist Heinrich
Hertz in his pioneering experiments to prove the existence of
electromagnetic waves predicted by the theory of James Clerk Maxwell.
Hertz placed dipole antennas at the focal point of parabolic
reflectors for both transmitting and receiving.
Today will see one example application of Antenna in A Survey on Emerging WiMAX Antenna Technologies and Slotted Microstrip Patch Antenna’s for WiMAX Applications
A Survey on Emerging WiMAX Antenna Technologies and Slotted Micro strip Patch Antenna’s for WiMAX Applications
ABSTRACT
WiMax (Worldwide Interoperability for Microwave access) has been established by the
IEEE 802.16 working group. WiMax
theoretically can have coverage of up to 50 km radius. WiMax technology is replacement
for wireless internet access. WiMax has
three allocated frequency bands. The low
band (2. 5-2.69 GHz), the middle band (3.2-3.8 GHz) and the upper band (5.2- 5.8 GHz).New WiMax antenna technologies like SISO,SIMO,MISO,MIMO,AAS are
developed which promises
increased data rates, greater bandwidth, security and more productive use of the
wireless spectrum. The antenna is very essential element of communication as it is used for a transmitting and receiving
electromagnetic waves. Today
Communication devices such as mobile phones become very thin and smarter, support several
applications and require higher
bandwidth where the microstrip antennas
are the better choice compare to
conventional antennas. This paper
presents a literature survey of slotted microstrip patch antenna’s these are Double C-slot MSA and C-slot MSA
for WiMAX applications. In this
paper we also discussed the basics of
microstrip antennas with their advantage and disadvantages.
Fig.-Structure of microstrip antenna
ANTENNA PARAMETERS
Performance of the antenna s measured by different parameter such as VSWR, Return Loss, Antenna
Gain, Directivity, Antenna Efficiency
and Bandwidth is analyzed.
(a) Gain: The gain of an antenna is
defined as the ratio of the intensity,
in a given direction, to the radiation intensity that would be obtained if the power accepted by the
antenna were radiated isotropically.
(b) Radiation Pattern: The
radiation pattern is defined as a mathematical
function or a graphical representation of the
radiation properties of the antenna as a function of space coordinates.
(c) Antenna Efficiency: It is a ratio of total power radiated by an antenna to the input power of an
antenna.
(d) Bandwidth: Is is range of frequencies over which antenna operates efficiently. Bandwidth
is difference between upper cutoff frequency and lower cut
off frequency.
(e) VSWR: Voltage standing wave ratio
is defined as VSWR=Vmax/Vmin.It should
lie between 1 and 2.
(f) Return loss: Return loss is the reflection of signal power from the insertion of a device in a transmission line. Hence the RL is a parameter similar to the VSWR to
indicate how well the matching between the
transmitter and antenna has taken place.
ADVANTAGES AND DISADVANTAGES
A. Advantages-
1. Low weight
2. Low profile
3. Require no cavity Backing
4. Linear & circular polarization
5. Capable of dual and triple frequency operation
6. Feed lines & matching network can be fabricated
simultaneously
B. Disadvantages-
1. Low efficiency
2. Low gain
3. Large ohmic losses in feed structure.
4. Low power handling capacity
5. Excitation of surface wave
6. Polarization purity is difficult to achieve.
7. Complex feed structure required high
performance arrays.
REFERENCE ARTICLES
- A 6-40 GHz CubeSAT Antenna System
- A Decoupled Multiband Dual-Antenna System for WWAN LTE Smartphone Applications
- A Miniaturized UWB Bi-Planar Yagi-Like MIMO Antenna System
- A New Compact Antenna Test Range for EW-Antenna System Production Testing
- A Simple Wireless Power Charging Antenna System Evaluation of Ferrite Sheet
If anyone is interested for doing Research in above subject for BTech/MTech/PHD Engineering project work
Kindly Contact Below
Contact Details:
Santosh Gore Sir
Ph:09096813348 / 8446081043 / 0253-6644344
Email: sai.info2009@gmail.com
Email: sai.info2009@gmail.com
No comments:
Post a Comment