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.
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.
Broadside Array vs end-fire array
Higher directivity.
Provide increased directivity in
elevation and azimuth planes.
Generally used for reception.
Impedance match difficulty in
high power transmissions.
Variants are:
Horizontal Array of Dipoles
RCA Fishborne Antenna
Series Phase Array
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.
A dipole antenna is the simplest antenna but its radiation characteristics are very good. The main drawback of a dipole antenna is very narrow bandwidth. The analysis of a dipole antenna can be performed with integration of Hertzian dipoles.
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.
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.
Broadside Array vs end-fire array
Higher directivity.
Provide increased directivity in
elevation and azimuth planes.
Generally used for reception.
Impedance match difficulty in
high power transmissions.
Variants are:
Horizontal Array of Dipoles
RCA Fishborne Antenna
Series Phase Array
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.
A dipole antenna is the simplest antenna but its radiation characteristics are very good. The main drawback of a dipole antenna is very narrow bandwidth. The analysis of a dipole antenna can be performed with integration of Hertzian dipoles.
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.
False Peaks Occuring at Direction-Finding Via Cylindrical Antenna Array with ...IJRESJOURNAL
ABSTRACT: In this paper the problem of DOA estimation methods for cylindrical antenna arrays is considered. The performances are estimated in various noise environments and for various geometries of the antenna arrays. Additionally the problem of false peaks occurring in spatial spectrum is closely considered. Probability of occurring false peaks after computer simulations is presented.
Antenna is used widely in the telecommunication field, military operations, and other applications. It gets an electromagnetic wave and converts it into electric signals. Some antennas receive electric signals and radiate them as electromagnetic waves. A simple radio antenna is a long straight rod. Many indoor TV antennas take the form of a dipole that is divided into 2 pieces and folded horizontally. Numerous outdoor TV antennas have more than one dipole with a central supporting rod. The different types of antenna designs include parabolic satellite dishes and circular loops of wire.
Generally, the waves emitting at the antenna from a transmitter are the same in any shape of the antenna. Different patterns of dipoles help to concentrate the signals for easy detection. This effect can be increased by adding many unconnected dummy dipoles called reflectors and directors. These dipoles bounce the signals over the actual receiving dipoles. This is similar to boosting the signals and picking weaker signals better than a simple antenna. We will further discuss the working of different kinds of antennas and the science behind their working. We will also discuss the various types of antennas and their different properties.
Important Features of Antennas
An Antenna contains many important features such as:
• Gain
The gain of an antenna is a technical measurement and the amount at which the signals are boosted. Television will pick up a poor signal without an antenna plugged in. Metal cases and other components pick up some kinds of signals by default. You need to add a proper directional antenna to gain better signals.
The gain of an antenna is often measured in decibels (DB). You will receive a better reception with a bigger gain. Outdoor antennas work more effectively than outdoor antennas.
• Directionality
Dipole is very directional and picks up incoming radio waves traveling at right angles to them. The telescopic antenna on an FM radio is less directional when the signals are strong. If the telescopic antenna is pointed straight upward, it will capture good signals from any direction.
AM antenna in the radio is very directional. While using AM, you will need to swivel the radio until it picks up strong signals. Highly directional antennas give ample benefits such as reduction in interference from unwanted sources or signals.
• Bandwidth
The bandwidth of an antenna refers to the frequency range on which it works perfectly. Broader bandwidth gives a greater range of radio waves. Broad bandwidth will be more helpful in the case of television but not in other cases like satellite communications, telephones, or cell phones.
Different Kinds of Antennas
An antenna is a tool used for receiving and transmitting signals. It comes in various shapes, sizes, and features according to the needs of the customers. We will now discuss the different types of antennas and how they work.
1. Dipole Antenna
Dipole antennas normally contain 2 similar conductive elements
Antenna parameters part 2 - PolarisationAndre Fourie
The polarisation specification for an antenna specifies how the electric field behaves in the far field (where the radiated wave has established itself).
Lens antenna is a microwave antenna in which a dielectric lens is placed in front of the dipole or horn radiator to concentrate the radiated energy into a narrow beam or to focus received energy on the receiving dipole or horn.
Microstrip antenna (also known as a printed antenna) usually means an antenna fabricated using microstrip techniques on a printed circuit board (PCB). They are mostly used at microwave frequencies.
The aperture is defined as the area, oriented perpendicular to the direction of an incoming radio wave, which would intercept the same amount of power from that wave as is produced by the antenna receiving it. A horn antenna or microwave horn is an antenna that consists of a flaring metal waveguide shaped like a horn to direct radio waves in a beam. Horns are widely used as antennas at UHF and microwave frequencies, above 300 MHz.
Frequency-independent (FI) antennas are radiating structures capable of maintaining consistent impedance and pattern characteristics over multiple-decade bandwidths. Their finite size limits the lowest frequency of operation, and the finite precision of the center region bounds the highest frequency of operation.
A loop antenna is a radio antenna consisting of a loop or coil of wire, tubing, or other electrical conductor with its ends connected to a balanced transmission line (or possibly a balun). There are two distinct antenna designs: the small loop (or magnetic loop) with a size much smaller than a wavelength, and the much larger resonant loop antenna with a circumference close to the intended wavelength of operation. Small loops have low radiation resistance and thus poor efficiency and are mainly used as receiving antennas at low frequencies. To increase the magnetic field in the loop and thus the efficiency, the coil of wire is often wound around a ferrite rod magnetic core; this is called a ferrite loop antenna. The ferrite loop is the antenna used in many AM broadcast receivers, with the exception of external loops used with AV Amplifier-Receivers and car radios; the antenna is often contained inside the radio's case. These antennas are also used for radio direction finding. In amateur radio, loop antennas are often used for low profile operating where larger antennas would be inconvenient, unsightly.
(c) WIkipedia
The dipole and the monopole are arguably the two most widely used antennas across the UHF, VHF and lower-microwave bands. Arrays of dipoles are commonly used as base-station antennas in land-mobile systems. The monopole and its variations are common in portable equipment, such as cellular telephones, cordless telephones, automobiles, trains, etc. It has attractive features such as simple construction, sufficiently broadband characteristics for voice communication, small dimensions at high frequencies. Alternatives to the monopole antenna for hand-held units is the inverted F and L antennas, the microstrip patch antenna, loop and spiral antennas, and others. The printed inverted F antenna (PIFA) is arguably the
most common antenna design used in modern handheld phones.
(c) Nikolova 2016
In radio and electronics, an antenna (plural antennae or antennas), or aerial, is an electrical device which converts electric power into radio waves, and vice versa.[1] It is usually used with a radio transmitter or radio receiver. In transmission, a radio transmitter supplies an electric current oscillating at radio frequency (i.e. a high frequency alternating current (AC)) 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.
A permanent magnet AC (PMAC) motor is a synchronous motor, meaning that its rotor spins at the same speed as the motor's internal rotating magnetic field. Other AC synchronous technologies include hysteresis motors, larger DC-excited motors, and common reluctance motors.
(c) beta.machinedesign.com
Inverters offer speed or torque control of electric motors.
Maybe you have walked past without noticing them or maybe you know exactly how many you have, either way electric motors play an important role in our everyday lives which most of us are unaware of but, they move and run most things we need for business and pleasure.
All these motors consume electricity so need a corresponding amount of energy to provide the torque or speed needed. If the torque or speed is too high or low, mechanical controls are used to control output. A motor’s speed should match exactly what is required by the process, otherwise the result is inefficiency with a lot of wasted materials and energy.
Not knowing how to control motors can mean a lot of energy gets wasted which isn’t good for any business. A way to control these motors, which not only saves energy, but improves productivity and reduces maintenance costs, is to use an inverter.
(c) inverterdrivesystems.com
Courier management system project report.pdfKamal Acharya
It is now-a-days very important for the people to send or receive articles like imported furniture, electronic items, gifts, business goods and the like. People depend vastly on different transport systems which mostly use the manual way of receiving and delivering the articles. There is no way to track the articles till they are received and there is no way to let the customer know what happened in transit, once he booked some articles. In such a situation, we need a system which completely computerizes the cargo activities including time to time tracking of the articles sent. This need is fulfilled by Courier Management System software which is online software for the cargo management people that enables them to receive the goods from a source and send them to a required destination and track their status from time to time.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
2. Course Outline
I) Introduction
A) Elements of Antenna
B) Gain or directivity of Antenna
II) Types of Array
A) Linear
1) 2-Element Array
2) N-element Linear Array with Uniform Amplitude and Spacing
B) Circular
C) Planar
3. Introduction
Antenna composes of elements
These elements has low values of directivity
In application, antennas are required to have
very high gains.
4. How to achieve greater gains
Increase the electrical size of the antenna
Enlarging the dimensions of single elements
The most efficient is to use an array.
5. What is an array?
An antenna array is a set of 2 or more
antennas. The signals from the antennas are
combined or processed in order to achieve
improved performance over that of a single
antenna.
-antenna theory
6. Tasks of Antenna Array
Increase the overall gain
Provide diversity reception
Cancel out interference from a particular set
of direction
Determine the direction of arrival of the
incoming signals
To maximize the Signal to Interference Plus
Noise Ratio(SINR)
11. The array elements are identical
They are oriented in the same way is space
(identical polarization)
Their excitation is of the same amplitude
12. N-element Linear Array with Uniform
Amplitude and Spacing
An array of identical elements with identical
magnitudes and with a progressive phase is
called a uniform array.
13.
14. Circular Array
antenna elements arranged around a circular
ring.
Applications are radio direction finding, air
and space navigation, underground
propagation, radar, sonar.
15.
16. Unlike linear arrays, circular arrays can provide a 2D
angular scan, both horizontal φ and vertical θ scans.
Unlike 2D planar arrays, circular arrays are basically 1D
linear arrays but in a circular form.
Unlike linear arrays, a circular array can scan
horizontally for 360° with no distortions near the end-
fire directions.
17. Planar arrays
Planar arrays are more versatile
Antenna elements arranged over
some planar surface (example
- rectangular array).
provide more symmetrical patterns
with lower side lobes
much higher directivity (narrow main beam).
Applications – tracking radars, remote sensing,
and communications.
