An antenna array consists of multiple spatially separated antenna elements that can be combined to improve performance over a single antenna. Antenna arrays allow for high gain, steerable beams, diversity reception, interference cancellation, and direction finding. The performance of an antenna array improves as more elements are added. Additionally, increasing the element spacing provides higher directivity, but the spacing must remain below half the wavelength to avoid grating lobes. Phased arrays use differences in phase between element signals to steer the beam electronically without mechanical movement. This allows for rapid scanning compared to mechanical antennas.
This thesis focuses on mobile phones antenna design with brief description about the historical development, basic parameters and the types of antennas which are used in mobile phones. Mobile phones antenna design section consists of two proposed PIFA antennas. The first design concerns a single band antenna with resonant frequency at GPS frequency (1.575GHz). The first model is designed with main consideration that is to have the lower possible PIFA single band dimensions with reasonable return loss (S11) and the efficiencies. Second design concerns in a wideband PIFA antenna which cover the range from 1800MHz to 2600MHz. This range covers certain important bands: GSM (1800MHz & 1900MHz), UMTS (2100MHz), Bluetooth & Wi-Fi (2.4GHz) and LTE system (2.3GHz, 2.5GHz, and 2.6GHz). The wideband PIFA design is achieved by using slotted ground plane technique. The simulations for both models are performed in COMSOL Multiphysics.
The last two parts of the thesis present the problems of mobile phones antenna. Starting with Specific absorption rate (SAR) problem, efficiency of Mobile phones antenna, and hand-held environment.
hello readers i give my PPT presentation for about antenna and ther properties and working explain in this ppt
i hope you like it THANK YOU.......!!!!!!!
This thesis focuses on mobile phones antenna design with brief description about the historical development, basic parameters and the types of antennas which are used in mobile phones. Mobile phones antenna design section consists of two proposed PIFA antennas. The first design concerns a single band antenna with resonant frequency at GPS frequency (1.575GHz). The first model is designed with main consideration that is to have the lower possible PIFA single band dimensions with reasonable return loss (S11) and the efficiencies. Second design concerns in a wideband PIFA antenna which cover the range from 1800MHz to 2600MHz. This range covers certain important bands: GSM (1800MHz & 1900MHz), UMTS (2100MHz), Bluetooth & Wi-Fi (2.4GHz) and LTE system (2.3GHz, 2.5GHz, and 2.6GHz). The wideband PIFA design is achieved by using slotted ground plane technique. The simulations for both models are performed in COMSOL Multiphysics.
The last two parts of the thesis present the problems of mobile phones antenna. Starting with Specific absorption rate (SAR) problem, efficiency of Mobile phones antenna, and hand-held environment.
hello readers i give my PPT presentation for about antenna and ther properties and working explain in this ppt
i hope you like it THANK YOU.......!!!!!!!
By completing this presentation will be have a clear idea about Antenna's working principles, Antenna's Types & Antenna's Parameters. At the end to this document you'll have a brief idea about Antenna's Tilt vs Distance Calculation & Cluster wise optimum Antenna Selection procedure. Impact of antenna PIM & VSWR have been described elaborately in this document as well.
An antenna array (or array antenna) is a set of multiple connected antennas which work together as a single antenna, to transmit or receive radio waves. The individual antenna elements are connected to a single receiver or transmitter by feedlines that feed the power to the elements in a specific phase relationship. The radio waves radiated by each individual antenna combine and superpose, adding together (interfering constructively) to enhance the power radiated in desired directions, and cancelling (interfering destructively) to reduce the power radiated in other directions. Similarly, when used for receiving, the separate radio frequency currents from the individual antennas combine in the receiver with the correct phase relationship to enhance signals received from the desired directions and cancel signals from undesired directions.
In radio and electronics, an antenna is an electrical device which converts electric power into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver. In transmission, a radio transmitter supplies an electric current oscillating at radio frequency 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 a tiny voltage at its terminals, that is applied to a receiver to be amplified.
An Antenna is a transducer, which converts electrical power into electromagnetic waves and vice versa.
An Antenna can be used either as a transmitting antenna or a receiving antenna.
A transmitting antenna is one, which converts electrical signals into electromagnetic waves and radiates them.
A receiving antenna is one, which converts electromagnetic waves from the received beam into electrical signals.
In two-way communication, the same antenna can be used for both transmission and reception.
Basic Parameters
Frequency
Wavelength
Impedance matching
VSWR & reflected power
Bandwidth
Percentage bandwidth
Radiation intensity.
Mobile Communication Academic Assignment
For B.Tech Electronics and Communication Engineering 7th Semester
Index:
1. Introduction
2. Techniques
3. Schemes
4. History
5. Digital an Analog Beamforming
6. Difference between Digital and Analog Beamforming
7. Analog Beamforming Working
8. Digital Beamforming Working with receiver and transmitter
9. Digital Beamforming Challenges with receiver and transmitter
10. Solutions to the Challenges
11. For Speech Audio
Source: Wikipedia, Research Papers etc
By completing this presentation will be have a clear idea about Antenna's working principles, Antenna's Types & Antenna's Parameters. At the end to this document you'll have a brief idea about Antenna's Tilt vs Distance Calculation & Cluster wise optimum Antenna Selection procedure. Impact of antenna PIM & VSWR have been described elaborately in this document as well.
An antenna array (or array antenna) is a set of multiple connected antennas which work together as a single antenna, to transmit or receive radio waves. The individual antenna elements are connected to a single receiver or transmitter by feedlines that feed the power to the elements in a specific phase relationship. The radio waves radiated by each individual antenna combine and superpose, adding together (interfering constructively) to enhance the power radiated in desired directions, and cancelling (interfering destructively) to reduce the power radiated in other directions. Similarly, when used for receiving, the separate radio frequency currents from the individual antennas combine in the receiver with the correct phase relationship to enhance signals received from the desired directions and cancel signals from undesired directions.
In radio and electronics, an antenna is an electrical device which converts electric power into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver. In transmission, a radio transmitter supplies an electric current oscillating at radio frequency 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 a tiny voltage at its terminals, that is applied to a receiver to be amplified.
An Antenna is a transducer, which converts electrical power into electromagnetic waves and vice versa.
An Antenna can be used either as a transmitting antenna or a receiving antenna.
A transmitting antenna is one, which converts electrical signals into electromagnetic waves and radiates them.
A receiving antenna is one, which converts electromagnetic waves from the received beam into electrical signals.
In two-way communication, the same antenna can be used for both transmission and reception.
Basic Parameters
Frequency
Wavelength
Impedance matching
VSWR & reflected power
Bandwidth
Percentage bandwidth
Radiation intensity.
Mobile Communication Academic Assignment
For B.Tech Electronics and Communication Engineering 7th Semester
Index:
1. Introduction
2. Techniques
3. Schemes
4. History
5. Digital an Analog Beamforming
6. Difference between Digital and Analog Beamforming
7. Analog Beamforming Working
8. Digital Beamforming Working with receiver and transmitter
9. Digital Beamforming Challenges with receiver and transmitter
10. Solutions to the Challenges
11. For Speech Audio
Source: Wikipedia, Research Papers etc
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdf
array and phased array antennna
1.
2. INTRODUCTION
• For some applications single element antennas are unable to
meet the gain or radiation pattern requirements.
• So, the concept of an antenna array was first introduced in
military applications in the 1940‟s .
• This development was significant in wireless communications
as it improved the reception and transmission patterns of
antennas used in these systems.
• The array also enabled the antenna system to be electronically
steered – to receive or transmit information primarily from a
particular direction without mechanically moving the structure.
3. ANTENNA ARRAY
• An antenna array is a set of N spatially separated antennas.
• Arrays in practice can have as few as N=2 elements, which is common for
the receiving arrays on cell phone towers.
• In general, array performance improves with added elements; therefore
arrays in practice usually have more elements.
• The signals from the individual antennas are combined or processed in
order to achieve improved performance over that of a single antenna.
4. Advantages of using antenna arrays
• They can provide a high gain (array gain) by using simple
antenna elements.
• They can provide the capability of a steerable beam, “steer”
the array so that it is most sensitive in a particular direction
• Provide diversity reception
• Cancel out interference from a particular set of directions
• Determine the direction of arrival of the incoming signals
5.
6.
7.
8. Azimuthal patterns of two element isotropic array with different distance and
phase difference
d=0.25*lambda & pd=0
d=0.25*lambda & pd=90
d=0.25*lambda & pd=180
d=0.50*lambda & pd=0
d=0.50*lambda & pd=90
d=0.50*lambda & pd=180
10. Influence of the number of elements and element spacing on the
array factor
• The array directivity increases with the number of elements
• The element spacing also has a large influence on the array factor as well. A
larger element spacing results in a higher directivity. However, the element
spacing is generally kept smaller than lambda/2 to avoid the occurrence of
grating lobes.
Directivity of a 5 elements array with 0.2 (red), 0.3 (green) and 0.5
(blue) element spacing
11. Directivity of a 5 elements
array with 0.5 (red), 0.75
(green) and 1 (blue) element
spacing
Directivity of a 5 elements
array with 1 (green), 1.5 (red)
and 2 (blue) element spacing
12. Phased array antenna
Phased array is a directive antenna made with individual radiating
sources (several units to thousands of elements).
Radiating elements might be: dipoles, open-ended waveguides, microstrip
antennas, helices etc.
The shape and direction of pattern is determined by relative phases
amplitudes applied to each radiating element.
A phased array antenna offers the possibility to steer the beam by means of
electronic control (a dedicated computer is required).
By altering the relative phase of the signal fed to each element the
direction of the beam can be moved because the direction of constructive
interference will move.
13.
Because Phased array radars require no physical movement, the beam can
scan at thousands of degrees per second, fast enough to irradiate and track
many individual targets, and still run a wide-ranging search periodically.
By simply turning some of the antennas on or off, the beam can be spread
for searching and narrowed for tracking, or even split into two or more
virtual radars.
14. Possible arrangements for phased array
Linear Arrays
• A Linear array consists of elements arranged in a straight line in one
dimension. These antenna consists of lines whose elements are fed about a
common phase shifter. A number of vertically about each other mounted
linear arrays form a flat antenna.
• Advantage: simple arrangement
• Disadvantage: Ray deflection only in a single plane possible
15. PLANAR ARRAY
• A Planar array is a two-dimensional configuration of elements arranged to lie in a plane.
The planar array may be thought of as a linear array of linear arrays.
• These antenna arrays completely consist of singles radiating elements and each of it
gets an own phase shifter. The elements are ordered in a matrix array. The planar
arrangement of all elements forms the complete phased-array antenna.
• Advantages: Beam steering in two planes is possible
• Disadvantage: complicated arrangement and more electronically controlled phase shifter
needed
16. Conformal arrays
• In a conformal array, they are mounted on a curved surface, and the phase
shifters also compensate for the different phase shifts caused by the varying
path lengths of the radio waves due to the location of the individual antennas
on the curved surface.
• Because the individual antenna elements must be small, conformal arrays are
typically limited to high frequencies in the UHF or microwave range, where
the wavelength of the waves is small enough that small antennas can be used.
17. Passive Electronically scanned array(PESA)
• It is simply phased array radar. It takes a signal from a single source, split it
up into hundreds of paths, some of them selectively delayed, and sends to
individual antennas.
•
The resulting broadcasts overlapped in space, and the interference patterns
between the individual signals are controlled in order to reinforce the signal in
certain directions, and mute it down in all others.
• The delays can be easily controlled electronically, allowing the beam to be
steered very quickly without having to move the antenna. It can scan a
volume of space much more quickly than a traditional mechanical system.
18. Active Electronically scanned array(AESA)
• It also known as active phased array radar is a type of phased
array radar whose transmitter and receiver functions are composed of
numerous small solid-state transmit/receive modules (TRMs).
•
AESAs aim their "beam" by broadcasting radio energy that interferes
constructively at certain angles in front of the antenna. They improve on
the older passive electronically scanned radars by spreading their
broadcasts out across a band of frequencies, which makes it very difficult
to detect over background noise.
19. • In Terms of Advantages the AESA system is typically better than PESA
because of following factors :
• because the Antenna Elements contain its own Transmitter and Receiver
modules and located Right behind the Radiator, it would have lower or even
No accidental loss , unlike her PESA sister which still require a connection to
be made between its RF source to Radiating elements , incidental loss may
occur.
• High fault tolerance, failure of some modules will not hamper the operation
of Radar (typical AESA Radar may contain 100++ Elements) however the
entire device would fail if the failure occurs in 10% of total module counts.
• No Single Point Failure , since basically each modules in active Version
contains its own transmitter and Receiver modules, the passive device however
since it still use single Transmitter device like Traveling Wave tube , failure of
the transmitter may hamper the RADAR operations
20. APPLICATIONS
• Phased array antennas are electrically steerable, which means the physical
antenna can be stationary. This concept can eliminate all the headaches of a
gimbal in a radar system. It can keep an antenna locked onto a satellite, when
the antenna is mounted on a moving platform.
• It is what allows a satellite to steer its beam around your continent without
having to deal with the "slight problem" associated with trying to point things in
space where every movement would require an equal and opposite mass to
move in order to keep the satellite stabilized.
• A phased array receiver can be mounted on the top of a commercial airplane's so
that all of the happy passengers can receive satellite television!
• It is also used for weather forecast and tracking missiles and aircrafts; such as
search radar and tracking radar.
21. REFERENCES
Antenna theory , Constantine A. Balanis, Wiley, 1997
Phased array antenna handbook, Robert J. Mailloux, Artech House, 1994
Hansen R. C., „Phased Array Antennas‟, Wiley
http://www.radartutorial.eu/06.antennas/an16.en.html