definition, speed, production, properties of electromagnetic waves and electromagnetic spectrum. waves in EM spectrum and their application in daily life.
definition, speed, production, properties of electromagnetic waves and electromagnetic spectrum. waves in EM spectrum and their application in daily life.
In this topic you will see:
Radio Wave System
History
Characteristics
Specifications
Advantages and Disadvantages
Three Devices (Mobile Device, Wi-Fi Device, GPS Device etc.)
In this topic you will see:
Radio Wave System
History
Characteristics
Specifications
Advantages and Disadvantages
Three Devices (Mobile Device, Wi-Fi Device, GPS Device etc.)
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
Module 1: Introduction Lectures 8 hrs.
Fundamentals of wireless communication technology – the electromagnetic spectrum – radio
propagation mechanisms – characteristics of the wireless channel – Mobile Ad-hoc Networks
(MANETS) and Wireless Sensor Networks (WSNs): concepts and architectures. Applications
of Ad-hoc and sensor networks. Design challenges in Ad-hoc and sensor networks.
A Level Physics - Telecommunications - A Basic Introduction
Sound waves
Microphones
Receivers and transmitters
Amplitude modulation (am)
Frequency modulation (fm)
MICROWAVES
Satellite Communication
Optical fibers
Attenuation
The Public Switched Telephone Network
This document contains all the necessary basic information to understand Antenna Basics with simple and to the point non mathematical description.
This document is suitable for those who wants to understand only basics of antenna wireless communication.
For any queries or suggestions please contact on : mansithakur0304@gmail.com
Contents:
Electromagnetic Spectrum and RF basics.
Antenna introduction and its parameters.
Some other important factors like radiation pattern and polarization
Types of antennas and mobile antenna designs
How radio wave propagates
CBSE Class 12 Physics Sample ebook, which helps you to understand the chapter in easy way also downaload sample papers and previous year papers and practice to solve the question on time. Download at www.misostudy.com.
CBSE Class 12 PCM Sample ebook, which helps you to understand the chapter in easy way also downaload sample papers and previous year papers and practice to solve the question on time. Download at www.misostudy.com.
CBSE Class 12 PCB Sample ebook, which helps you to understand the chapter in easy way also downaload sample papers and previous year papers and practice to solve the question on time. Download at www.misostudy.com.
A short ppt on unguided aka wireless networks with a follow up in a non technical manner so that it is easy to explain and answer questions upon it is not intended to be used as a ppt for teaching but for rather a student to give explanation on per sem projects .... enjoy
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Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
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Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
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💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
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2. Introduction to Communication
2
The discipline of communication focuses on how people use messages to generate
meanings within and across various contexts, cultures, channels, and media.
The discipline promotes the effective and ethical practice of human communication.
Communication is representation of ongoing message exchange between individuals,
or an individual and a group of individuals, with the goal of understanding each
other.
A communicator encodes (e.g., puts thoughts into words and gestures), then
transmits the message via a channel (e.g., speaking, email, text message, radio aids)
to the other communicator(s) who then decode the message (e.g., take the words
and apply meaning to them).
4. History of Communication
4
Radio has its roots in the Telegraph.
This device was the first widely-used form of
long-distance communication.
In 1836, Samuel Morse invented a language
of dots and dashes that is still used today.
In 1876, Alexander Graham Bell transmitted
the human voice over wires for the first time.
Soon, his invention moved from the lab to
the home and life hasn't been the same since.
5. History of Communication
5
In 1887, Heinrich Hertz demonstrated that electromagnetic waves could be
transmitted through the air.
As a result, the term "Hertz" is now used to specify cycles per second for the
frequency of both sound and radio waves.
6. History of Communication
6
Guglielmo Marconi is commonly credited as inventing radio in 1895 even
though there is credible evidence that other inventors were first.
Once Marconi patented his invention in England, his next step was to sell it to
the marine industry.
Soon, the majority of oceangoing ships
were all equipped with his equipment –
which made Marconi a very rich man.
7. Waves
7
Waves: In physics, a wave is disturbance or oscillation (of a physical quantity),
that travels through matter or space, accompanied by a transfer of
energy. Wave motion transfers energy from one point to another, often with
no permanent displacement of the particles of the medium—that is, with little
or no associated mass transport. They consist, instead, of oscillations or
vibrations around almost fixed locations.
8. Waves
8
There are two main types of waves. Mechanical waves propagate through a
medium, and the substance of this medium is deformed.
For example, sound waves propagate via air molecules colliding with their
neighbors.
9. Waves
9
The second main type of wave, electromagnetic waves, do not require a
medium. Instead, they consist of periodic oscillations of electrical and
magnetic fields generated by charged particles, and can therefore travel
through a vacuum. These types of waves vary in wavelength, and include radio
waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-
rays, and gamma rays.
10. Form of the wave
10
The form or shape of the wave
Sine
Square
Triangle
Saw tooth
11. Basic Terms
11
Power supply: is an electronic device that supplies electric energy to an electrical
load. The primary function of a power supply is to convert one form of electrical
energy to another and, as a result, power supplies are sometimes referred to
as electric power converters. Some power supplies are discrete, stand-alone
devices, whereas others are built into larger devices along with their loads.
Examples of the latter include power supplies found in desktop
computers and consumer electronics devices.
12. Waves specifications
12
Frequency: is the number of occurrences of a repeating event per unit time.
For cyclical processes, such as rotation, oscillations, or waves, frequency is
defined as a number of cycles per unit time.
Radio frequency (RF) is a rate of oscillation of a wave per unit of time (per
second) and is typically measured in hertz.
F=Frequency
C=Speed of light waves
=Lambda (wave length)
14. Waves specifications
14
Wavelength: of a sinusoidal wave is the special period of the wave—the
distance over which the wave's shape repeats, generally is measured in
meters.
Assuming a sinusoidal wave moving at a fixed wave speed, wavelength is
inversely proportional to frequency of the wave: waves with higher
frequencies have shorter wavelengths, and lower frequencies have longer
wavelengths. In the case of electromagnetic radiation—such as light—in free
space is the speed of light, about 3×108 m/s.
16. Waves specifications
16
Amplitude: of a periodic variable is a measure of its change over a
single period (such as time or special period).
Peak-to-peak amplitude is the change between peak (highest amplitude value)
and trough (lowest amplitude value, which can be negative). With appropriate
circuitry, peak-to-peak amplitudes of electric oscillations can be measured by
meters or by viewing the waveform on an
oscilloscope.
18. Radio Waves Broadcasting Introduction
18
In radio transmission, it is necessary to send audio signal (e.g. music, speech
etc.) from a broadcasting station over great distances to a receiver. This
communication of audio signal does not employ any wire and is sometimes
called wireless. The audio signal cannot be sent directly over the air for
appreciable distance. Even if the audio signal is converted into electrical signal,
the latter cannot be sent very far without employing large amount of power.
The energy of a wave is directly proportional to its frequency. At audio
frequencies (20 Hz to 20 kHz), the signal power is quite small and radiation is
not practicable. The radiation of electrical energy is practicable only at high
frequencies e.g. above 20 kHz. The high frequency signals can be sent
thousands of miles even with comparatively small power.
19. Radio Waves Broadcasting Introduction
19
Therefore, if audio signal is to be transmitted properly, some means must be
devised which will permit transmission to occur at high frequencies while it
simultaneously allows the carrying of audio signal. This is achieved by
superimposing electrical audio signal on high frequency carrier.
The resultant waves are known as modulated waves or radio waves and the
process is called modulation. At the radio receiver, the audio signal is extracted
from the modulated wave by the process
called demodulation. The signal is then
amplified and reproduced into sound
by the loudspeaker.
20. Radio Broadcasting, Transmission and Reception
20
Radio communication means the radiation of radio waves by the transmitting
station, the propagation of these waves through space and their reception by
the radio receiver. Down figure shows the general principles of radio
broadcasting, transmission and reception. As a matter of convenience, the
entire arrangement can be divided into three parts viz. transmitter,
transmission of radio waves and radio receiver.
22. Radio Broadcasting, Transmission and Reception
22
Transmitter: Transmitter is an extremely important equipment and is housed
in the broadcasting station. Its purpose is to produce radio waves for
transmission into space. The important components of a transmitter are
microphone, audio amplifiers, oscillator and modulator.
23. Radio Broadcasting, Transmission and Reception
23
Microphone: A microphone (Transducer) is a device which converts sound
waves into electrical waves. When the speaker speaks or a musical instrument
is played, the varying air pressure on the microphone generates an audio
electrical signal which corresponds in frequency to the original signal. The
output of microphone is fed to a multistage audio amplifier for raising the
strength of weak signal.
24. Radio Broadcasting, Transmission and Reception
24
Amplifier: An electronic amplifier, amplifier, or (informally) amp is an
electronic device that increases the power of a signal. The amplifier is often
described as the heart or the nervous system of a microphone or loudspeaker.
The audio signal from the microphone is quite weak and requires
amplification. This job is accomplished by audio amplifiers. The amplified
output from the last audio amplifier is fed to the modulator for rendering the
process of modulation.
25. Radio Waves Broadcasting Introduction
25
Oscillation: is the repetitive variation, typically in time, of some measure
about a central value (often a point of equilibrium) or between two or more
different states. Familiar examples include a
swinging pendulum and alternating current power. The term vibration is
sometimes used more narrowly to mean a mechanical oscillation but is
sometimes used as a synonym of "oscillation".
26. Radio Broadcasting, Transmission and Reception
26
Oscillator: The function of oscillator is to produce a high frequency signal,
called a carrier wave. Usually, a crystal oscillator is used for the purpose. The
power level of the carrier wave is raised to a sufficient level by radio frequency
amplifier stages. Most of the broadcasting stations have carrier wave power of
several kilowatts. Such high power is necessary for transmitting the signal to
the required distances.
27. Radio Broadcasting, Transmission and Reception
27
Modulation: A high frequency carrier wave is used to carry the audio signal.
The question arises how the audio signal should be ‘‘added’’ to the carrier
wave. The solution lies in changing some characteristic of carrier wave in
accordance with the signal. Under such conditions, the audio signal will be
contained in the resultant wave. This process is called modulation and may be
defined as under : The process of changing some characteristic (e.g. amplitude,
frequency or phase) of a carrier wave in accordance with the intensity of the
signal is known as modulation.
Modulation means to “change”. In modulation, some characteristic of carrier
wave is changed in accordance with the intensity (i.e. amplitude) of the signal.
The resultant wave is called modulated wave or radio wave and contains the
audio signal. Therefore, modulation permits the transmission to occur at high
frequency while it simultaneously allows the carrying of the audio signal.
28. Radio Broadcasting, Transmission and Reception
28
Types of Modulation: As you will recall, modulation is the process of changing
amplitude or frequency or phase of a carrier wave in accordance with the
intensity of the signal. Accordingly, there are three basic types of modulation,
namely ;
(i) amplitude modulation (ii) frequency modulation (iii) phase modulation
In India, amplitude modulation is used in radio broadcasting. However, in
television transmission, frequency modulation is used for sound signal and
amplitude modulation for picture signal. Therefore, our attention in this
chapter shall be confined to the first two most important types of modulation.
29. Radio Broadcasting, Transmission and Reception
29
Amplitude Modulation: When the amplitude of high frequency carrier wave is
changed in accordance with the intensity of the signal, it is called amplitude
modulation. In amplitude modulation, only the amplitude of the carrier wave
is changed in accordance with the intensity of the signal. However, the
frequency of the modulated wave remains the same. The amplitude variations
of the carrier wave is at the signal frequency. Amplitude modulation is done by
an electronic circuit called modulator.
30. Radio Broadcasting, Transmission and Reception
30
Frequency Modulation (FM): When the frequency of carrier wave is changed in
accordance with the intensity of the signal, it is called frequency modulation
(FM). In frequency modulation, only the frequency of the carrier wave is changed
in accordance with the signal. However, the amplitude of the modulated wave
remains the same. The frequency variations of carrier wave depend upon the
instantaneous amplitude of the signal as shown down. When the signal voltage is
zero as at A, C, E and G, the carrier frequency is unchanged. When the signal
approaches its positive peaks as at B and F, the carrier frequency is increased to
maximum as shown by the closely spaced cycles. However, during the negative
peaks of signal as at D, the carrier frequency is reduced to minimum as shown by
the widely spaced cycles.
31. Radio Broadcasting, Transmission and Reception
31
Operating range. The energy of a wave depends upon its frequency. The
greater the frequency of the wave, the greater the energy possessed by it. As
the audio signal frequencies are small, therefore, these cannot be transmitted
over large distances if radiated directly into space. The only practical solution
is to modulate a high frequency carrier wave with audio signal and permit the
transmission to occur at this high frequency (i.e. carrier frequency).
Wireless communication. One desirable feature of radio transmission is that it
should be carried without wires i.e. radiated into space. At audio frequencies,
radiation is not practicable because the efficiency of radiation is poor.
However, efficient radiation of electrical energy is possible at high frequencies
(> 20 kHz). For this reason, modulation is always done in communication
systems.
32. Radio Broadcasting, Transmission and Reception
32
Advantages : The following are the advantages of FM over AM : It gives
noiseless reception. As discussed before, noise is a form of amplitude
variations and a FM receiver will reject such signals.
(ii) The operating range is quite large.
(iii) It gives high-fidelity reception.
(iv) The efficiency of transmission is very high.
34. Radio Broadcasting, Transmission and Reception
34
Antenna: Suppose you're the boss of a radio station and you want to transmit
your programs to the wider world. How do you go about it? You
use microphones to capture the sounds of people's voices and turn them into
electrical energy. You take that electricity and, loosely speaking, make it flow
along a tall metal antenna (boosting it in power many times so it will travel just
as far as you need into the world). An antenna (or aerial) is an electrical device
which converts electric currents into radio waves and vice versa. As the electrons
(tiny particles inside atoms) in the electric current wiggle back and forth along
the antenna, they create invisible electromagnetic radiation in the form of radio
waves. These waves travel out at the speed of light, taking your radio program
with them. What happens when I turn on my radio in my home a few miles
away? The radio waves you sent flow through the metal antenna and cause
electrons to wiggle back and forth. That generates an electric current—a signal
that the electronic components inside my radio turn back into sound I can hear.
35. Radio Broadcasting, Transmission and Reception
35
Types of Antenna: Vertical and Horizontal Polarization antennas.
Directional and Non-Directional antennas.
The simplest radio antennas are just long straight rods. Many indoor TV
antennas take the form of a dipole: a metal rod split into two pieces and
folded horizontally. Other designs include circular loops of wire and, of course,
parabolic satellite dishes. Three features of antennas are particularly
important, namely their,, and.
Directionality: they pick up incoming radio waves traveling at right angles to
them.
Gain: amount by which it boosts the signal.
Bandwidth: An antenna's bandwidth is the range of frequencies (or
wavelengths, if you prefer) over which it works effectively.
36. Radio Broadcasting, Transmission and Reception
36
(i) Practical antenna length. Theory shows that in order to transmit a wave
effectively, the length of the transmitting antenna should be approximately
equal to the wavelength of the wave.
37. Radio Broadcasting, Transmission and Reception
37
Receiver: we tune the desired radio channel and An antenna catch enough of
the transmitted electromagnetic waves to provide an electrical signal level
sufficient for the receiver to process the signal into useful audio and video. In
next slides we will discuss the main parts of and receiver.
38. Radio Broadcasting, Transmission and Reception
38
Demodulation: The process of recovering the audio signal from the modulated
wave is known as demodulation or detection. At the broadcasting station,
modulation is done to transmit the audio signal over larger distances to a
receiver. When the modulated wave is picked up by the radio receiver, it is
necessary to recover the audio signal from it. This process is accomplished in
the radio receiver and is called demodulation.
Essentials in Demodulation: In order that a modulated wave is audible, it is
necessary to change the nature of modulated wave. This is accomplished by a
circuit called detector. A detector circuit performs the following two functions :
39. Radio Broadcasting, Transmission and Reception
39
It rectifies the modulated wave i.e. negative half of the modulated wave is
eliminated.
It separates the audio signal from the carrier. The rectified modulated wave
contains the audio signal and the carrier. It is desired to recover the audio
signal. This is achieved by a filter circuit which removes the carrier frequency
and allows the audio signal to reach the load i.e.speaker.
40. Radio Broadcasting, Transmission and Reception
40
The FM receiver is more complicated and, therefore, more expensive than the
normal AM receiver. The FM radio receiver receives its input from an antenna,
uses electronic filters to separate a wanted radio signal from all other signals
picked up by this antenna, amplifies it to a level suitable for further processing,
and finally converts it through demodulation and decoding the signal into a
form usable for the consumer, such as sound, pictures, digital data,
measurement values, navigational positions, etc. The receiver is tuned to
respond preferentially to the desired signals, and reject undesired signals.
41. Radio Broadcasting, Transmission and Reception
41
De-amplifier: is an electronic device that decreases the power of a signal. The
de-amplifier is often described as the heart or the nervous system of a
microphone or loudspeaker. The audio signal from the de-modulator is
powerful and requires de-amplification. This job is accomplished by audio de-
amplifiers. The de-amplified output from the last audio de-amplifier is fed to
the loudspeaker for converting the electrical wave to the sound wave.
42. Radio Broadcasting, Transmission and Reception
42
Loudspeaker: When things shake about, or vibrate, they make the sounds we
can hear in the world around us. Sound is invisible most of the time, but
sometimes you can actually see it! If you thump a kettle-drum with a stick, you
can see the tight drum skin moving up and down very quickly for some time
afterward—pumping sound waves into the air.
43. Radio Broadcasting, Transmission and Reception
43
At the front of a loudspeaker, there is a fabric, plastic, paper, or lightweight
metal cone (sometimes called a diaphragm). The outer part of the cone is
fastened to the outer part of the loudspeaker's circular metal rim. The inner part
is fixed to an iron coil (voice coil, colored orange in the diagram) that sits just in
front of a permanent magnet (field magnet, and colored yellow). When electrical
signals feed through the speaker cables (red) into the coil. This turns the coil into
a temporary magnet or electromagnet. As the electricity flows back and forth in
the cables, the electromagnet either attracts or repels the permanent magnet.
This moves the coil back and forward, pulling and pushing the loudspeaker cone.
Like a drum skin vibrating back and forth, the moving cone pumps sounds out
into the air.
44. Radio Broadcasting, Transmission and Reception
44
In next chapter you will study about HF, VHF & UHF Communication
equipment's.
Any Question?