Frequency Independent Antennas:
Wide band antennas
Frequency independent bandwidth in octave range
Broadband antennas
Frequency independent bandwidth in the range 40:1
Multiband antennas
Antenna resonate at different frequencies.
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.
Its a good presentation on Antenna topic because every one is know that in electrical engineering antenna is a complete subject & its too much difficult subject of electrical engineering....I hope this ppt slides helpful in your future...Thanks A lot guys.......
KINDLY REGARDS
KHAWAJA SHAHBAZ IQBAL
ELECTRICAL ENGINEER
UNIVERSITY OF CENTRAL PUNJAB ,LAHORE ,PAKISTAN
+923360690272
This document discusses various types of antennas and antenna arrays. It begins by describing common antenna types including helical antennas, horn antennas, and parabolic reflector antennas. It then discusses how antenna arrays work, noting that they are composed of multiple similar radiating elements whose spacing and excitation determine the array's properties. Examples of linear and 2D arrays are provided. The document also summarizes different array configurations and beamforming techniques as well as applications such as smart antennas and adaptive arrays. Key benefits of arrays like controlling radiation patterns electronically are highlighted.
- Antennas convert electric currents into radio waves and vice versa. They are used in various technologies including radio, television, mobile phones, WiFi, and radar.
- The first antennas were built in 1888 by Heinrich Hertz to transmit and receive electromagnetic waves. Modern antennas come in different types for applications like broadcasting, communications, and space exploration.
- Antennas work by using an oscillating current to generate oscillating electric and magnetic fields that propagate as radio waves. During reception, the antenna intercepts some power from incoming radio waves to produce a voltage for the receiver.
This document discusses amplitude modulation (AM) as a type of modulation used to transmit information signals. Modulation involves varying a high frequency carrier signal by an information signal in order to transmit the information signal over long distances. In AM, the amplitude of the carrier signal is varied in accordance with the instantaneous amplitude of the modulating or information signal. This creates two new sideband frequencies above and below the carrier frequency equal to the modulation frequency. The carrier and sidebands together make up the modulated signal. Only a portion of the transmitted power is present in the sidebands containing the information, while the rest is wasted in the carrier.
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
Reflector antennas use a reflecting surface to direct the radiation pattern of a feeding element. Parabolic reflectors provide highly directional beams by reflecting waves from a feed at the focus into a parallel beam. Reflectors can have different shapes like flat sheets, corners, parabolas, ellipses, and hyperbolas. Parabolic reflectors are widely used in applications like television, communication, and radio astronomy due to their ability to produce a narrow beam. The feed is a key component and common options include dipoles, horns, and Cassegrain feeds which place the feed behind the reflector. Design factors like the focal length to diameter ratio determine properties like beamwidth and efficiency.
This document provides an overview of smart antennas. It begins with a brief history, noting that smart antennas were initially developed for military communications and intelligence gathering. The document defines smart antennas as antenna arrays that can adaptively change their pattern in response to signal environments to improve communication channel performance. It describes the key components and functioning of smart antennas, including digital beamforming and direction of arrival estimation techniques. The main types of smart antennas are explained as adaptive array antennas and switched beam array antennas. Advantages like reduced interference and increased capacity are outlined. Applications in mobile communications, satellites, and wireless networks are also mentioned.
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.
Its a good presentation on Antenna topic because every one is know that in electrical engineering antenna is a complete subject & its too much difficult subject of electrical engineering....I hope this ppt slides helpful in your future...Thanks A lot guys.......
KINDLY REGARDS
KHAWAJA SHAHBAZ IQBAL
ELECTRICAL ENGINEER
UNIVERSITY OF CENTRAL PUNJAB ,LAHORE ,PAKISTAN
+923360690272
This document discusses various types of antennas and antenna arrays. It begins by describing common antenna types including helical antennas, horn antennas, and parabolic reflector antennas. It then discusses how antenna arrays work, noting that they are composed of multiple similar radiating elements whose spacing and excitation determine the array's properties. Examples of linear and 2D arrays are provided. The document also summarizes different array configurations and beamforming techniques as well as applications such as smart antennas and adaptive arrays. Key benefits of arrays like controlling radiation patterns electronically are highlighted.
- Antennas convert electric currents into radio waves and vice versa. They are used in various technologies including radio, television, mobile phones, WiFi, and radar.
- The first antennas were built in 1888 by Heinrich Hertz to transmit and receive electromagnetic waves. Modern antennas come in different types for applications like broadcasting, communications, and space exploration.
- Antennas work by using an oscillating current to generate oscillating electric and magnetic fields that propagate as radio waves. During reception, the antenna intercepts some power from incoming radio waves to produce a voltage for the receiver.
This document discusses amplitude modulation (AM) as a type of modulation used to transmit information signals. Modulation involves varying a high frequency carrier signal by an information signal in order to transmit the information signal over long distances. In AM, the amplitude of the carrier signal is varied in accordance with the instantaneous amplitude of the modulating or information signal. This creates two new sideband frequencies above and below the carrier frequency equal to the modulation frequency. The carrier and sidebands together make up the modulated signal. Only a portion of the transmitted power is present in the sidebands containing the information, while the rest is wasted in the carrier.
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
Reflector antennas use a reflecting surface to direct the radiation pattern of a feeding element. Parabolic reflectors provide highly directional beams by reflecting waves from a feed at the focus into a parallel beam. Reflectors can have different shapes like flat sheets, corners, parabolas, ellipses, and hyperbolas. Parabolic reflectors are widely used in applications like television, communication, and radio astronomy due to their ability to produce a narrow beam. The feed is a key component and common options include dipoles, horns, and Cassegrain feeds which place the feed behind the reflector. Design factors like the focal length to diameter ratio determine properties like beamwidth and efficiency.
This document provides an overview of smart antennas. It begins with a brief history, noting that smart antennas were initially developed for military communications and intelligence gathering. The document defines smart antennas as antenna arrays that can adaptively change their pattern in response to signal environments to improve communication channel performance. It describes the key components and functioning of smart antennas, including digital beamforming and direction of arrival estimation techniques. The main types of smart antennas are explained as adaptive array antennas and switched beam array antennas. Advantages like reduced interference and increased capacity are outlined. Applications in mobile communications, satellites, and wireless networks are also mentioned.
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.......!!!!!!!
The document discusses different types of antennas and their properties. It describes how antennas convert radio frequency energy into electromagnetic waves and how their physical size relates to wavelength. It then summarizes the main types of antennas including directional antennas like Yagi, panel and parabolic, and omni-directional antennas. It provides examples of common antenna radiation patterns and discusses concepts like polarization, reflector optics, aperture efficiency, and Cassegrain feeds.
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.
A type of aerial, widely used with television and VHF radio receivers, consisting of two parallel dipoles connected together at their outer ends and fed at the center of one of them. The length is usually half the operating wavelength.
The document discusses beamforming antennas and their applications. It begins by outlining beamforming concepts and configurations like phased arrays and adaptive arrays. It then discusses applications of beamforming antennas in areas like radar, sonar, communications and imaging. Specific examples covered include phased array radar, neuronal spike sorting, and smart antenna systems for wireless networks. Vector antennas and their advantages over phased arrays are also summarized. Finally, the document discusses potential uses and challenges of beamforming antennas for wireless ad hoc networks.
This document provides an overview of microwave tubes, including their components and operating principles. It discusses cavity resonators, rectangular cavity resonators, limitations of conventional vacuum tubes at high frequencies, and types of microwave tubes like klystrons, traveling wave tubes (TWTs), and magnetrons. Magnetrons are used in microwave ovens and produce hundreds of watts of microwave power by directing an electron beam in a circular pattern using a strong magnetic field. TWTs amplify signals in the microwave frequency range from 500 MHz to 300 GHz using an electron beam interacting with a slow-wave structure.
This narrated power point presentation attempts to explain the various dispersion mechanisms that are observed in optical fibers. Some fundamental terms and concepts are also discussed. The material will be useful for KTU final year B Tech students who prepare for the subject EC 405, Optical Communications.
An antenna converts radio frequency electric current into electromagnetic waves that are radiated into space. The same antenna can transmit and receive signals. Key antenna concepts include reciprocity, radiation patterns, gain, and polarization. Antenna gain compares its power output to an isotropic antenna. Common antennas include dipole, parabolic reflective, and types are optimized for propagation modes like ground wave, sky wave, and line-of-sight. Signal strength is reduced by factors like free space loss, noise, multipath, and fading over the transmission path.
FM transmitters and receivers are used for sending and receiving FM signals. Transmitters modulate a carrier wave with an audio signal to generate an FM signal, which is transmitted through a band. Receivers receive the modulated signal, demodulate it to extract the original audio signal. FM offers advantages over AM like noise reduction, improved fidelity, and more efficient power use, though it requires more complex circuits and a larger bandwidth. Applications of FM include radio broadcasting, mobile radio, TV sound, and cellular/satellite communication.
MicroStrip Antenna
Introduction .
Micro-Strip Antennas Types .
Micro-Strip Antennas Shapes .
Types of Substrates (Dielectric Media) .
Comparison of various types of flat profile printed antennas .
Advantages & DisAdvantages of MSAs .
Applications of MSAs .
Radiation patterns of MSAs .
How to Optimizing the Substrate Properties for Increased Bandwidth ?
Comparing the different feed techniques .
Diversity Techniques in mobile communicationsDiwaker Pant
The document discusses diversity techniques in wireless communication. It introduces different types of diversity including frequency diversity and time diversity. Frequency diversity involves transmitting the same information over multiple carrier frequencies separated by more than the coherence bandwidth. Time diversity involves repeated transmission of information with time spacing exceeding the channel coherence time. The document provides examples of how techniques like frequency division multiplexing and rake receivers implement frequency and time diversity respectively.
Introduction To Wireless Fading ChannelsNitin Jain
The document summarizes key concepts related to wireless fading channels, including:
1. Multipath fading causes fluctuations in signal strength over small physical distances due to constructive and destructive interference from multiple signal paths.
2. Rayleigh fading occurs when there is no line-of-sight path between transmitter and receiver, resulting in fast, large fluctuations in signal strength over small physical distances.
3. Doppler spread and coherence time describe how quickly the wireless channel varies over time due to mobility, with fast fading occurring if the channel changes significantly within a symbol period.
Diversity Techniques in Wireless CommunicationSahar Foroughi
This document discusses diversity techniques for wireless communication, including cooperative diversity. It begins by introducing wireless systems and the impairments they face like fading. It then covers various diversity techniques like space, frequency, and time diversity that provide multiple transmission paths to reduce fading. Cooperative diversity is described as allowing single-antenna devices to achieve MIMO-like benefits by sharing antennas. The document outlines cooperative transmission protocols and challenges at different network layers in implementing cooperation. In conclusion, diversity techniques improve performance by providing multiple signal replicas to overcome fading, while cooperation enables reliability and throughput gains with challenges to address across protocol layers.
Design & Study of Microstrip Patch Antenna.The project here provides a detailed study of how to design a probe-fed Square Micro-strip Patch Antenna using HFSS, v11.0 software and study the effect of antenna dimensions Length (L), and substrate parameters relative Dielectric constant (εr), substrate thickness (t) on the Radiation parameters of Bandwidth and Beam-width.
This document discusses array antennas. It defines an array antenna as a group of antennas connected and arranged to form a single antenna that can produce radiation patterns not possible with individual antennas. Array antennas are used to increase gain, provide diversity, cancel interference, and steer sensitivity in a particular direction. The two main types are parasitic arrays, which control beams like radar, and driven arrays, which have less loss but maintain narrow beams. Key characteristics of array antennas discussed include gain, beamwidth, bandwidth, pattern, directivity, and applications like mobile communication, broadcasting, and guidance systems.
The Smith chart is a graphical tool used to analyze high frequency circuits. It represents all possible complex impedances in terms of the reflection coefficient. Circles of constant resistance and arcs of constant reactance intersect on the chart to indicate impedance values. The chart allows users to determine impedances, reflection coefficients, voltage standing wave ratios and other transmission line parameters through graphical techniques. It remains a popular tool decades after its original conception due to providing a clever way to visualize complex impedance functions.
This document describes different types of antennas used for transmitting and receiving electromagnetic waves. It discusses transmitter and receiver antennas. Specific antenna types covered include Yagi-Uda antennas, log-periodic antennas, helix antennas, parabolic antennas, loop antennas, and antenna arrays. Each antenna type has distinct characteristics that make it suitable for different frequency ranges and applications.
This document provides an overview of optical fiber communication. It begins with introducing optical fibers and how they guide light through total internal reflection. It then describes the different types of optical fibers, including step index and graded index fibers. The key elements of an optical fiber communication system are presented, along with the benefits such as high bandwidth, low loss, and electrical isolation. Applications include telecommunications networks, computing, and military systems. In conclusion, while optical fibers have some disadvantages, they have revolutionized communications due to their wide bandwidth and low transmission losses.
This document summarizes information about spiral antennas. It begins with an introduction and history, noting that spiral antennas were first developed in 1954 by Edwin Turner. It then discusses key aspects of spiral antennas such as their very large bandwidth of up to 30:1, circular polarization, gains typically between 2-8dB, and the two main types - Archimedean and log-periodic spirals. Parameters for designing spiral antennas and their applications are also covered, along with conclusions about their advantages for wideband operation and disadvantages related to their complex geometric forms.
A broadband antenna means the antenna with wideband radiation characteristics. To make a broadband antenna, we can use a helical, a biconical, a sleeve, a spiral, and a log-periodic antenna.
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.......!!!!!!!
The document discusses different types of antennas and their properties. It describes how antennas convert radio frequency energy into electromagnetic waves and how their physical size relates to wavelength. It then summarizes the main types of antennas including directional antennas like Yagi, panel and parabolic, and omni-directional antennas. It provides examples of common antenna radiation patterns and discusses concepts like polarization, reflector optics, aperture efficiency, and Cassegrain feeds.
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.
A type of aerial, widely used with television and VHF radio receivers, consisting of two parallel dipoles connected together at their outer ends and fed at the center of one of them. The length is usually half the operating wavelength.
The document discusses beamforming antennas and their applications. It begins by outlining beamforming concepts and configurations like phased arrays and adaptive arrays. It then discusses applications of beamforming antennas in areas like radar, sonar, communications and imaging. Specific examples covered include phased array radar, neuronal spike sorting, and smart antenna systems for wireless networks. Vector antennas and their advantages over phased arrays are also summarized. Finally, the document discusses potential uses and challenges of beamforming antennas for wireless ad hoc networks.
This document provides an overview of microwave tubes, including their components and operating principles. It discusses cavity resonators, rectangular cavity resonators, limitations of conventional vacuum tubes at high frequencies, and types of microwave tubes like klystrons, traveling wave tubes (TWTs), and magnetrons. Magnetrons are used in microwave ovens and produce hundreds of watts of microwave power by directing an electron beam in a circular pattern using a strong magnetic field. TWTs amplify signals in the microwave frequency range from 500 MHz to 300 GHz using an electron beam interacting with a slow-wave structure.
This narrated power point presentation attempts to explain the various dispersion mechanisms that are observed in optical fibers. Some fundamental terms and concepts are also discussed. The material will be useful for KTU final year B Tech students who prepare for the subject EC 405, Optical Communications.
An antenna converts radio frequency electric current into electromagnetic waves that are radiated into space. The same antenna can transmit and receive signals. Key antenna concepts include reciprocity, radiation patterns, gain, and polarization. Antenna gain compares its power output to an isotropic antenna. Common antennas include dipole, parabolic reflective, and types are optimized for propagation modes like ground wave, sky wave, and line-of-sight. Signal strength is reduced by factors like free space loss, noise, multipath, and fading over the transmission path.
FM transmitters and receivers are used for sending and receiving FM signals. Transmitters modulate a carrier wave with an audio signal to generate an FM signal, which is transmitted through a band. Receivers receive the modulated signal, demodulate it to extract the original audio signal. FM offers advantages over AM like noise reduction, improved fidelity, and more efficient power use, though it requires more complex circuits and a larger bandwidth. Applications of FM include radio broadcasting, mobile radio, TV sound, and cellular/satellite communication.
MicroStrip Antenna
Introduction .
Micro-Strip Antennas Types .
Micro-Strip Antennas Shapes .
Types of Substrates (Dielectric Media) .
Comparison of various types of flat profile printed antennas .
Advantages & DisAdvantages of MSAs .
Applications of MSAs .
Radiation patterns of MSAs .
How to Optimizing the Substrate Properties for Increased Bandwidth ?
Comparing the different feed techniques .
Diversity Techniques in mobile communicationsDiwaker Pant
The document discusses diversity techniques in wireless communication. It introduces different types of diversity including frequency diversity and time diversity. Frequency diversity involves transmitting the same information over multiple carrier frequencies separated by more than the coherence bandwidth. Time diversity involves repeated transmission of information with time spacing exceeding the channel coherence time. The document provides examples of how techniques like frequency division multiplexing and rake receivers implement frequency and time diversity respectively.
Introduction To Wireless Fading ChannelsNitin Jain
The document summarizes key concepts related to wireless fading channels, including:
1. Multipath fading causes fluctuations in signal strength over small physical distances due to constructive and destructive interference from multiple signal paths.
2. Rayleigh fading occurs when there is no line-of-sight path between transmitter and receiver, resulting in fast, large fluctuations in signal strength over small physical distances.
3. Doppler spread and coherence time describe how quickly the wireless channel varies over time due to mobility, with fast fading occurring if the channel changes significantly within a symbol period.
Diversity Techniques in Wireless CommunicationSahar Foroughi
This document discusses diversity techniques for wireless communication, including cooperative diversity. It begins by introducing wireless systems and the impairments they face like fading. It then covers various diversity techniques like space, frequency, and time diversity that provide multiple transmission paths to reduce fading. Cooperative diversity is described as allowing single-antenna devices to achieve MIMO-like benefits by sharing antennas. The document outlines cooperative transmission protocols and challenges at different network layers in implementing cooperation. In conclusion, diversity techniques improve performance by providing multiple signal replicas to overcome fading, while cooperation enables reliability and throughput gains with challenges to address across protocol layers.
Design & Study of Microstrip Patch Antenna.The project here provides a detailed study of how to design a probe-fed Square Micro-strip Patch Antenna using HFSS, v11.0 software and study the effect of antenna dimensions Length (L), and substrate parameters relative Dielectric constant (εr), substrate thickness (t) on the Radiation parameters of Bandwidth and Beam-width.
This document discusses array antennas. It defines an array antenna as a group of antennas connected and arranged to form a single antenna that can produce radiation patterns not possible with individual antennas. Array antennas are used to increase gain, provide diversity, cancel interference, and steer sensitivity in a particular direction. The two main types are parasitic arrays, which control beams like radar, and driven arrays, which have less loss but maintain narrow beams. Key characteristics of array antennas discussed include gain, beamwidth, bandwidth, pattern, directivity, and applications like mobile communication, broadcasting, and guidance systems.
The Smith chart is a graphical tool used to analyze high frequency circuits. It represents all possible complex impedances in terms of the reflection coefficient. Circles of constant resistance and arcs of constant reactance intersect on the chart to indicate impedance values. The chart allows users to determine impedances, reflection coefficients, voltage standing wave ratios and other transmission line parameters through graphical techniques. It remains a popular tool decades after its original conception due to providing a clever way to visualize complex impedance functions.
This document describes different types of antennas used for transmitting and receiving electromagnetic waves. It discusses transmitter and receiver antennas. Specific antenna types covered include Yagi-Uda antennas, log-periodic antennas, helix antennas, parabolic antennas, loop antennas, and antenna arrays. Each antenna type has distinct characteristics that make it suitable for different frequency ranges and applications.
This document provides an overview of optical fiber communication. It begins with introducing optical fibers and how they guide light through total internal reflection. It then describes the different types of optical fibers, including step index and graded index fibers. The key elements of an optical fiber communication system are presented, along with the benefits such as high bandwidth, low loss, and electrical isolation. Applications include telecommunications networks, computing, and military systems. In conclusion, while optical fibers have some disadvantages, they have revolutionized communications due to their wide bandwidth and low transmission losses.
This document summarizes information about spiral antennas. It begins with an introduction and history, noting that spiral antennas were first developed in 1954 by Edwin Turner. It then discusses key aspects of spiral antennas such as their very large bandwidth of up to 30:1, circular polarization, gains typically between 2-8dB, and the two main types - Archimedean and log-periodic spirals. Parameters for designing spiral antennas and their applications are also covered, along with conclusions about their advantages for wideband operation and disadvantages related to their complex geometric forms.
A broadband antenna means the antenna with wideband radiation characteristics. To make a broadband antenna, we can use a helical, a biconical, a sleeve, a spiral, and a log-periodic antenna.
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
This document discusses different types of antennas, including horn antennas, slot antennas, microstrip or patch antennas, quad-helix antennas, and notch antennas. It provides details on the purpose, design, and applications of each antenna type. Horn antennas are used to direct radio waves in a beam from a waveguide and have high gain. Slot antennas consist of a metal surface with a cut-out hole or slot that radiates waves similarly to a dipole antenna. Microstrip antennas can be printed on circuit boards and are widely used in mobile devices due to their low cost. Quad-helix antennas have four connected helix antennas and transmit measurements from remote areas. Notch antennas operate based on a cut-out section similar to
1) The document reports on the design and testing of a 7-turn helical antenna with a gain of 10 dBi and VSWR less than 2.0 at a frequency of 2 GHz.
2) Through calculations, the antenna parameters were determined and the design was simulated using NEC software. The initial simulation results showed a VSWR of 1.57 at the design frequency.
3) The antenna was physically constructed and tested, with the measured gain peaking at the design frequency, though there were discrepancies with the simulated results due to real-world testing conditions.
A balun is used to connect an unbalanced transmission line, like coaxial cable, to a balanced antenna. Without a balun, the currents on each side of the balanced antenna would not be equal, causing improper operation. A balun forces the outer current on the coaxial cable to be zero, which balances the currents on each side of the antenna. There are different types of baluns that can be used to choke off the outer current, including sleeve baluns, folded baluns, tapered baluns, and infinite baluns. Baluns ensure balanced operation between an unbalanced transmission line and a balanced antenna component.
An antenna converts electric power to radio waves and vice versa. It is usually used with a radio transmitter or receiver. There are several types of antennas including wire antennas, traveling wave antennas, reflector antennas, microstrip antennas, log-periodic antennas, and aperture antennas. A patch antenna is a type of radio antenna that is low profile and can be mounted on a flat surface. It consists of a flat metal patch mounted over a larger ground plane. Patch antennas are widely used today in applications like satellite communication, GPS, and mobile devices due to their compact size and light weight.
1) ANU-MIMO is a proposed decentralized, scalable, and economical wireless network designed to provide long-range broadband connectivity using massive MIMO technology.
2) Unlike cellular networks, ANU-MIMO is non-cellular and distributes service nodes and beamforming to increase throughput and range as more nodes are added.
3) Simulations show ANU-MIMO can provide error-free broadband connectivity to over 1,000 clients within a 200km range using low power and achieving throughputs comparable to LTE but in a way that remains constant per client as the network scales.
The document describes the design process of a Vivaldi antenna. It begins with a rectangular copper sheet that has a slot cut into it. Adding a feed turns it into a basic antenna. Shortening the slot shifts resonances to higher frequencies. Tapering the slot improves bandwidth and matching. Tapering both sides creates the Vivaldi antenna with its very broad bandwidth and high efficiency across frequencies. The direction of peak radiation depends on the frequency band in use. Modifying the short circuit path can help with tuning but does not change the radiation.
This document defines and describes various fundamental properties of antennas including radiation patterns, field regions, directivity, gain, bandwidth, polarization, input impedance, and the Friis transmission equation. It provides definitions and equations for quantifying properties like radiation intensity, directive gain, directivity, beamwidth, radar cross section, and the radar range equation. Diagrams are included to illustrate concepts such as radiation lobes, coordinate systems, and geometries used in transmission equations.
A high gain antenna is the antenna with very high antenna gain. We can consider antenna gain as concentration ratio of input power. Using Yagi-Uda array, traveling wave, aperture, and parabolic reflector, we can design a high gain antenna.
This document discusses small scale fading in telecommunications. Small scale fading, also known as multipath induced fading, is caused by multipath propagation which results in multiple versions of a transmitted signal arriving at the receiver with different amplitudes, phases, and time delays. The interference between these multipath signals causes rapid fluctuations in signal strength over short periods of time. The document describes factors that influence small scale fading such as multipath propagation and Doppler shift. It also defines different types of fading including flat fading, frequency selective fading, fast fading, and slow fading. Statistical models for modeling multipath fading channels are also presented.
This document outlines a course on fundamentals of wireless communication. The course aims to study the fundamentals and new research developments in the field in a unified way. The topics covered include basics of the wireless channel, diversity techniques, capacity of wireless channels, MIMO systems, and wireless networks. Spatial multiplexing, channel modeling, diversity-multiplexing tradeoff, and opportunistic communication in multiuser systems are some specific concepts discussed. Modern wireless systems like GSM, CDMA2000, and OFDM are used as examples to illustrate the concepts.
A family of operating systems developed and produced by Microsoft Corp. It provides a software graphical user interface (GUI) used on IBM and compatible computers.
Keltron is an electronics development corporation established by the Kerala state government in 1977. It has four business units: control and instrumentation, pneumatic products, information technology, and strategic services. The strategic services group manufactures towed array systems for defense applications. A towed array is a long cable with hydrophones trailed behind a ship to detect submarines and missiles. It allows detection over long distances, though positioning of the hydrophones must be continuously monitored. The internship report summarizes the student's two week training at Keltron, during which he learned about the company's departments and products like towed arrays and computers.
An electron gun generates an electron beam that is interacting with a slow-wave structure.
It sustains the oscillations by propagating a traveling wave backwards against the beam
. The generated electromagnetic wave power has its group velocity directed oppositely to the direction of motion of the electrons.
The output power is coupled out near the electron gun.
This document describes the design and simulation of a helical antenna for naval communication at 18.6 MHz. Key details include the antenna dimensions such as monopole height of 595mm, helix pitch length of 20mm, and 25 turns. Simulation results show a resonance frequency of 18.6MHz and S11 of -9.5dB. Radiation patterns are also presented. Additionally, the document discusses cylindrical strip antennas designed and simulated in HFSS, including resonance frequencies and radiation patterns.
This document discusses several topics related to antenna design and performance:
1) It provides a brief history of major antenna discoveries from the 1920s to the 1970s, including Yagi-Uda antennas, horn antennas, arrays, parabolic reflectors, and patch antennas.
2) It explains how antennas work by describing how electric and magnetic fields propagate as waves.
3) Key factors that influence antenna performance are described, including frequency band, surrounding fields, size effects, efficiency, directivity, gain, impedance matching, and bandwidth.
Interstage buffer B1 feeds the Decode stage with a newly-fetched instruction.
Interstage buffer B2 feeds the Compute stage with the two operands
Interstage buffer B3 holds the result of the ALU operation
Interstage buffer B4 feeds the Write stage with a value to be written into the register file
The document discusses different types of antennas used for radio transmission and reception. It categorizes antennas into several groups: log periodic antennas, wire antennas, travelling wave antennas, microwave antennas, and reflector antennas. Within each category, specific antenna types are described, including their basic design and purpose. Key antenna types mentioned include dipole antennas, monopole antennas, Yagi-Uda arrays, parabolic reflectors, horn antennas, and slot antennas.
An antenna converts electric power into radio waves and vice versa. There are two main categories of antennas - omnidirectional antennas that radiate in all directions, and directional antennas that preferentially radiate in a particular direction. Key parameters that define antennas include frequency, directivity, efficiency, gain, wavelength, and polarization. Common types of antennas discussed are Yagi antennas, log-periodic antennas, horn antennas, loop antennas, and parabolic antennas.
This document discusses different types of antennas used in radio and electronics. It describes that antennas convert electric power to radio waves and vice versa. Antennas are categorized as either omnidirectional or directional. Key parameters that define antennas like frequency, directivity, and gain are also outlined. Specific antenna types discussed include Yagi-Uda, log-periodic, horn, loop, parabolic, and their uses.
This document discusses different types of antennas used for transmitting and receiving electromagnetic waves. It describes log-periodic antennas, which work over a wide frequency range using a logarithmic size progression of elements. Specific types are described, including bow-tie antennas and log-periodic dipole arrays. Wire antennas like dipoles, monopoles, and loops are also covered. Travelling wave antennas transmit signals along their length, represented by helical and Yagi-Uda antennas. Microwave antennas and reflector antennas are used at higher frequencies for applications like communication and radar. Key antenna properties and a variety of applications are also summarized.
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.
The document discusses different types of antennas used in wireless communication. It describes antennas such as dipole antennas, horn antennas, parabolic dish antennas, and antenna arrays. Dipole antennas are simple and widely used. They consist of two conductive elements that transmit and receive electromagnetic waves. Horn antennas guide radio waves into a beam but have limited directivity. Parabolic dish antennas have high gain and directivity due to their distinctive parabolic shape. Antenna arrays combine the radiation patterns of individual antenna elements to provide benefits such as high gain and directivity.
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 broadband antenna is a radio antenna that can transmit signals over a wide ...VasuhiSamydurai1
This document discusses various types of broadband antennas that can operate over a wide range of frequencies. It describes biconical antennas, log periodic antennas, sleeve antennas, spiral antennas, and helical antennas. Helical antennas are highlighted as being directional, circularly polarized antennas that can provide both high gain and wide bandwidth, making them well-suited for applications involving space telemetry where signals may experience Faraday rotation. The document suggests that helical antennas can be adapted to operate over multiple bands.
Millimeter wave circular microstrip Patch antenna for 5 g applicationsGana U Kumar
The document describes the design of a millimeter wave microstrip patch antenna for 5G applications operating at 28GHz. Key points:
1) A circular microstrip patch antenna was designed on Roger RT/duroid 5880 substrate with dielectric constant of 2.2 and thickness of 0.508mm.
2) The antenna was simulated using HFSS and achieved over 7dB gain, bandwidth over 1GHz, and return loss below -15dB at the target frequency of 28GHz.
3) To further increase gain, a 1x4 circular patch antenna array was designed and is expected to improve performance over a single element for 5G communication systems.
The document discusses the Yagi-Uda antenna, which consists of a driven element connected to a transmitter or receiver, along with multiple parasitic elements called reflectors and directors that help direct radio waves. It operates based on the principle that elements of specific lengths resonate at particular frequencies. The reflector is longer than the driven element to reflect waves forward, while progressively shorter directors increase directivity. Yagi-Uda antennas are commonly used for television reception due to their high gain and directionality over long distances.
Parabolic antennas use a curved parabolic reflector to direct radio waves into a narrow beam. They work by reflecting radio waves from a feed antenna located at the focal point of the parabolic dish into a parallel beam when transmitting, and focusing incoming plane waves to the feed antenna when receiving. Parabolic antennas provide high gain and directivity due to their large reflector sizes. They find applications in satellite communication, microwave links, radio astronomy, and direct broadcast television due to their ability to direct signals over long distances with strong reception.
The document provides an overview of antenna options and considerations for TV stations moving to high band or low band VHF as part of the spectrum repacking process. It discusses omni-directional and directional antenna types for each band, including slotted pylons, batwing antennas, Lindenblad antennas, inverted vee antennas, and panel antennas. For high band VHF, it also covers topics like beam tilt, elliptical polarization, manufacturing lead times, and Micronetixx's online antenna design tool.
Quick Way to Know about Antenna and Its TypeGurleen Nayar
An antenna plays a significant role in the realm of wireless communication. It is a metallic structure designed for receiving and transmitting a wide range of radiofrequency waves wirelessly.
Benefits of Gwave Technology's Log-Periodic and ka Band AntennaGwave Technology
Leading RF and microwave solutions provider Gwave Technology offers a variety of antennas for diverse applications. Gwave log-periodic antenna and Ka band antenna are explored for their unique features, usage, and wireless communication benefits.
Design and Analysis of Cylindrical Arc Array AntennaIRJET Journal
This document describes the design and analysis of a cylindrical arc array antenna. It begins by discussing microstrip patch antennas and their limitations. Conformal antennas are introduced as a type of antenna that can overcome some of the limitations of planar and circular antennas. The design of a single patch antenna is described using equations to calculate the length and width. Then, an array of 8 single patch antennas conformed into a cylindrical arc shape is proposed. Simulation results using CST software show that the cylindrical arc array antenna achieves improved parameters like return loss, voltage standing wave ratio, gain, and directivity compared to a single patch antenna, making it useful for applications in the S-band frequency range.
This document discusses different types of antennas used in wireless communication systems. It begins with an introduction to antennas and their basic parameters. The document then covers the history of antenna development. Several common antenna types are described, including Yagi-Uda antennas, log-periodic antennas, horn antennas, loop antennas, and parabolic antennas. Each antenna type is defined along with its advantages and applications. The document concludes that antennas play an important role in converting signals for transmission and reception in modern wireless technologies.
Kerala Engineering Architecture Medical is an entrance examination series for admissions to various professional degree courses in the state of Kerala, India. It is conducted by the Office of the Commissioner of Entrance Exams run by the Government of Kerala
Paleontology is the study of the history of life on Earth as based on fossils. Fossils are the remains of plants, animals, fungi, bacteria, and single-celled living things that have been replaced by rock material or impressions of organisms preserved in roc
This document provides an overview of basic chemistry concepts. It defines chemistry as the study of matter and its properties. The main branches of chemistry are described as organic, inorganic, physical, industrial, analytical, biochemistry, and nuclear chemistry. Matter is classified as pure substances or mixtures based on its composition. Elements are the basic units that make up all matter and can exist as atoms or molecules. Chemical properties and reactions are governed by laws such as the law of conservation of mass. The mole concept is introduced as a unit used to quantify the amount of substance.
1. The document provides an overview of key concepts in ecology including definitions of ecology, environment, biotic and abiotic factors, levels of biological organization, niche, adaptation, species, populations, communities, ecosystems, producers, consumers, trophic levels, food chains, food webs, ecological pyramids, biotic interactions, symbiosis, biomes, and ecological succession.
2. Key terms are defined such as ecology, environment, producers, consumers, trophic levels, competition, predation, symbiosis, mutualism, commensalism, parasitism, biome, primary succession and secondary succession.
3. Examples are provided to illustrate various ecological concepts and interactions between organisms.
The ways in which an element—or compound such as water—moves between its various living and nonliving forms and locations in the biosphere is called a biogeochemical cycle. Biogeochemical cycles important to living organisms include the water, carbon, nitrogen, phosphorus, and sulfur cycles.
The AC and DC bridge both are used for measuring the unknown parameter of the circuit. The AC bridge measures the unknown impedance of the circuit. The DC bridge measures the unknown resistance of the circuit.
This document discusses three types of electronic bridges: Hays Bridge, Scherings Bridge, and Wien Bridge. It presents topics on each bridge but does not provide any details about their applications or functions. The document lists the three bridge types but lacks descriptions and explanations.
For most of us, our name existed even before we did.
In anticipation of our arrival, our parents went through an ultra stressful process of narrowing down dozens of potential names until they chose the perfect one.
Luckily they did, because whatever your name is, it has followed you throughout your entire life; and in some cases, people may have heard of your name before they’ve ever met you.
When it comes to how to name an app, it’s of similar importance as naming a child. The name of your app will follow your brand forever, and in many cases, potential users will hear the name before they ever actually use your app.
flora and fauna of himachal pradesh and keralaAJAL A J
flora and fauna of himachal pradesh and kerala
A green pearl in the Himalayan crown, Himachal Pradesh is blessed with a rich flora and fauna that graces the land with grandeur and majesty. Other animals that can be sighted in the wild include the ibex, wild yak, ghoral deer, musk deer, Himalayan black bear, brown bear, leopards and the Himalayan Thar. Also kerala is gods on country
Bachelor of Science in Cardio-vascular technology is an undergraduate course in cardiology. These technologists assist the physicians in the diagnosis and the treatment of cardiac (heart) and peripheral vascular conditions (blood vessels). The cardiovascular technologists are also responsible for preparing the patients for open-heart surgeries and pacemaker implantation surgeries. The technologists also monitor the patient’s cardiac parameters while they undergo the surgery. B. Sc. in Cardiovascular technology is a three years’ full-time undergraduate course and is an interesting and important course in medicine.
`Remove Unprofitable Products and Services. The products or services with the highest gross profit margin are the most important to your business. ...
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PCOS is a condition characterized by the formation of cysts in the ovaries caused by increased levels of male hormones preventing ovulation. It can be diagnosed through hormonal testing, ultrasound detection of cysts, and can be caused by genetic or metabolic factors like obesity. Women with PCOS have a higher risk of health issues like infertility, gestational diabetes, and miscarriage during pregnancy and require careful monitoring. Homeopathic, Ayurvedic, and Siddha medicines may help treat PCOS through regulating hormones and the menstrual cycle.
Courses and Career Options after Class 12 in HumanitiesAJAL A J
This document provides information on career and course options after completing class 12 in humanities. It discusses options in several fields such as geography, anthropology, economics, psychology, social work, foreign languages, history, and sports/physical education. For each field, it provides a brief introduction, lists relevant courses and areas of work, and describes some example courses and institutes. The document aims to help students choose the right career path after 12th humanities. It ends by asking if the reader is ready to take their career to the next level.
The document provides guidance on preparing for the NEET exam over different time periods. It outlines important topics in physics, botany, and zoology for NEET. A 180-day and 60-day preparation strategy are presented. General tips are provided, such as understanding the exam pattern, clearly knowing the syllabus, prioritizing subjects, taking scheduled breaks, and regularly evaluating preparation through practice tests.
This document provides information about career counseling services offered by Ajal A J, including a message about his objectives and previous experience in career counseling. It also contains a presentation about revolutions in agriculture and making farms more profitable through out-of-box thinking. Contact information is provided to get in touch with Ajal A J for career counseling or agricultural consulting services.
Are you an NRI and aiming to come back to India to pursue graduation from the top-tier colleges of India?
Then, you’re halfway there. Being an NRI, your top preference would be IITs and NITs of India. If that's the case, you must know the fee structure of both the IITs, NITs (under DASA scheme), Centrally Funded Institutions and State-Level Govt. Engineering Colleges.
Note: According to the latest update from DASA, from session 2021-22 onwards, JEE Rank is made mandatory for NRI/PIO/OCI Students to be eligible for DASA & CIWG Schemes. Hence, 2020-21 will be the last year when SAT 2 scores will be considered for DASA/CIWG Scheme.
Subjects to study if you want to work for a charityAJAL A J
The charity sector can be competitive and experience, volunteer or otherwise, can count for a lot. But there are ways to make that third sector CV stand out from the competition. Why not take some courses? A course can be a great way to make your application shine and an opportunity to learn new skills and ideas.
Joint Entrance Examination - Main or commonly known as JEE Main is a national level entrance exam conducted by the NTA to offer admission to BE/BTech, BPlan and BArch courses at the IIITs (Indian Institute of Information Technology), NITs (National Institute of Technology) and other Centrally Funded Technical Institutions (CFTIs) across the country.
The CLAT 2020 exam will now be held on August 22nd in a computer-based online format. The application deadline has been extended to July 10th. The exam will contain 150 multiple choice questions testing English, current affairs, legal reasoning, and quantitative skills. It provides admission to 22 national law universities in India.
KuberTENes Birthday Bash Guadalajara - K8sGPT first impressionsVictor Morales
K8sGPT is a tool that analyzes and diagnoses Kubernetes clusters. This presentation was used to share the requirements and dependencies to deploy K8sGPT in a local environment.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...shadow0702a
This document serves as a comprehensive step-by-step guide on how to effectively use PyCharm for remote debugging of the Windows Subsystem for Linux (WSL) on a local Windows machine. It meticulously outlines several critical steps in the process, starting with the crucial task of enabling permissions, followed by the installation and configuration of WSL.
The guide then proceeds to explain how to set up the SSH service within the WSL environment, an integral part of the process. Alongside this, it also provides detailed instructions on how to modify the inbound rules of the Windows firewall to facilitate the process, ensuring that there are no connectivity issues that could potentially hinder the debugging process.
The document further emphasizes on the importance of checking the connection between the Windows and WSL environments, providing instructions on how to ensure that the connection is optimal and ready for remote debugging.
It also offers an in-depth guide on how to configure the WSL interpreter and files within the PyCharm environment. This is essential for ensuring that the debugging process is set up correctly and that the program can be run effectively within the WSL terminal.
Additionally, the document provides guidance on how to set up breakpoints for debugging, a fundamental aspect of the debugging process which allows the developer to stop the execution of their code at certain points and inspect their program at those stages.
Finally, the document concludes by providing a link to a reference blog. This blog offers additional information and guidance on configuring the remote Python interpreter in PyCharm, providing the reader with a well-rounded understanding of the process.
The CBC machine is a common diagnostic tool used by doctors to measure a patient's red blood cell count, white blood cell count and platelet count. The machine uses a small sample of the patient's blood, which is then placed into special tubes and analyzed. The results of the analysis are then displayed on a screen for the doctor to review. The CBC machine is an important tool for diagnosing various conditions, such as anemia, infection and leukemia. It can also help to monitor a patient's response to treatment.
International Conference on NLP, Artificial Intelligence, Machine Learning an...gerogepatton
International Conference on NLP, Artificial Intelligence, Machine Learning and Applications (NLAIM 2024) offers a premier global platform for exchanging insights and findings in the theory, methodology, and applications of NLP, Artificial Intelligence, Machine Learning, and their applications. The conference seeks substantial contributions across all key domains of NLP, Artificial Intelligence, Machine Learning, and their practical applications, aiming to foster both theoretical advancements and real-world implementations. With a focus on facilitating collaboration between researchers and practitioners from academia and industry, the conference serves as a nexus for sharing the latest developments in the field.
CHINA’S GEO-ECONOMIC OUTREACH IN CENTRAL ASIAN COUNTRIES AND FUTURE PROSPECTjpsjournal1
The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
reserves and the ancient silk trade route, along with China's diplomatic endeavours in the area, has been
referred to as the "New Great Game." This research centres on the power struggle, considering
geopolitical, geostrategic, and geoeconomic variables. Topics including trade, political hegemony, oil
politics, and conventional and nontraditional security are all explored and explained by the researcher.
Using Mackinder's Heartland, Spykman Rimland, and Hegemonic Stability theories, examines China's role
in Central Asia. This study adheres to the empirical epistemological method and has taken care of
objectivity. This study analyze primary and secondary research documents critically to elaborate role of
china’s geo economic outreach in central Asian countries and its future prospect. China is thriving in trade,
pipeline politics, and winning states, according to this study, thanks to important instruments like the
Shanghai Cooperation Organisation and the Belt and Road Economic Initiative. According to this study,
China is seeing significant success in commerce, pipeline politics, and gaining influence on other
governments. This success may be attributed to the effective utilisation of key tools such as the Shanghai
Cooperation Organisation and the Belt and Road Economic Initiative.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
6. Frequency Independent Antennas:
Wide band antennas
Frequency independent bandwidth in
octave range
Broadband antennas
Frequency independent bandwidth in
the range 40:1
Multiband antennas
Antenna resonate at different
frequencies.
24. Log- periodic Antenna
• A log-periodic antenna (LP)
Is a multi-element, directional, narrow-beam antenna
Operates over a broad band of frequencies.
Log Periodic Tooth AntennaLog Periodic Dipole Antenna
40. The bandwidth of a microstrip antenna is increased
by using a thicker and lower-dielectric-constant
substrate, or by using multi-resonator gap-coupled
and stacked configurations, or by cutting a resonant
slot inside the patch.
However, with all of these methods, the bandwidth
of the antenna is limited by the probe's inductance
for substrate thicknesses greater than 0.06λo to
0.07λo.
For substrate thicknesses larger than 0.07λo, the
bandwidth of the antenna can be increased by using
a proximity-feeding method.
41.
42.
43.
44. Introduction – Vivaldi Antenna
• The Vivaldi antenna, sometimes referred to as or the Vivaldi
notch antenna, and also known as the tapered slot antenna
(TSA), is easy to fabricate on a circuit board, and can provide
ultra-wide wide bandwidth.
45. Vivaldi Antenna
• A Vivaldi-antenna is a co-planar broadband-antenna, which is
made from a dielectric plate metalized on both sides.
• Peter Gibson invented the Vivaldi antenna in 1978, in the UK.
• By properly designing the Vivaldi elements to reduce mutual
coupling, antenna arrays can be designed to operate over a decade
of frequency and to scan more than 45 degrees from broadside.
52. •Different Frequency bands for mobile communication:
GSM 900/1800/1900 bands (890-960 MHz and 1710-1990 MHz);
UMTS 3G expansion bands (1900-2200 MHz and 2500-2700 MHz);
Bluetooth & Wi-Fi (Wireless Fidelity)/Wireless Local Area
Networks (WLAN) bands (2400-2500 MHz and 5100-5800 MHz).