Radio Waves and its Applications in the Modern World (Research Proposal Sample)

RADIOWAVES AND ITS APPLICATIONS IN MODERN WORLD
NAME OF AUTHORS
NAME OF THE INSTITUTION
Author’sinformation
ACKNOWLEDGMENT
This research was supported by American University Washington DC. We thank our colleagues from American University who provided insight, and expertise that greatly assisted the research and also supported us financially so that we can come up with this manuscript. We are very grateful. Thank you and God bless you all.
Abstract- Radio Physics is a branch of physics which deals with the theoretical and experimental study of different kind of radiations: how radiations are emitted, their propagation and their interaction with the matter. Radiophysics, in short, can be described as the study of radio waves. This paper focuses on the study of radio waves, their history, their propagation i.e. how they travel between the medium and their applications in our modern day world. This paper aims at bringing to understanding the radio waves which are playing a very great role in modernising our environment
Index Terms- Radio waves, wavelength, amplitude, propagation, frequency, electromagnetic radiation, transmitter, antennae, transmitters, emitters, wireless
HISTORY OF RADIO WAVES
They were first discovered by mathematical work done by James Clerk Maxwell a mathematical physicist on 1867 whereby Maxwell noticed wavelike properties of light and similarities in electrical and magnetic observation. Later James Clerk Maxwell developed a mathematical theory called Maxwell equations. He described radio waves as the waves of electromagnetism that travel in space which is radiated by the charged particles as they undergo acceleration.[8]
In 1887, Heinrich Hertz demonstrated the reality of Maxwell’s electromagnetic waves by experimentally generating radio waves in his laboratory. As He studied the properties which were exhibited, He discovered that they had the same properties as the light i.e. Standing waves, refraction, diffraction, polarisation. Radio waves were first used in the mid-1890s by Guglielmo Marconi an Italian inventor and electrical engineer who developed the first practical radio transmitters and receivers. [8]
General radio timeline
Below are listed atimeline of the radio from 1880s-1990s which show how the discovery of radio waves has resulted in the various invention and adjustment up to our modern wireless communication which is widely known because of Mobile Phones and Radios.[5]
1885- Heinrich Hertz proved that electricity can be transmitted in electromagnetic waves. He conducted experiments in sending and receiving these waves during the late 1880s.
1891- Wireless Telegraph began to appear on ships at sea. This invention reduced the isolation
of the ships which lead to improved reliability and safety
1892-1893: Nikola Tesla wirelessly transmitted electromagnetic energy. He made the first public demonstration of radio in St Louis in 1893
1896-1897: Guglielmo Marconi filed for patent protection of his radio apparatus. He established the wireless telegraph and a signal company in 1897.
1899: The R.F. Mathews was the first ship to request emergency assistance using a wireless apparatus i.e. Marconi’s System
1901- First transAtlantic signal sent by Marconi from Ireland to Canada
1902: Amateur radio introduced to the U.S. via a scientific article. i.e. “How to Construct an Efficient Wireless Telegraphy Apparatus at a Small Cost.”
1906: Reginald Fessenden was the first to transmit a program of speech and music.
1906: Lee Deforest produced the “Audion”, a triode vacuum tube that allowed for amplification of radio signals
1910: First Radio transmission from an aeroplane
1912: Federal regulation of American waves begins Amateurs had to be licensed; ships had to have a radio and trained operators
1917: All U.S. radio station not needed by the government were shut downs
1918: Edwin Armstrong patented the super Heterodyne receiver based on work he did as an officer in the Army Signal Corp.
1927: The federal Radio Commission established to bring order to chaotic airwaves.
1947: Cellular radio telephone with call handoff and frequency re-use, was conceived at Bell Laboratories.
1970: The FCC reallocated TV channels 70-83 for mobile radio services
1985: The FCC permitted spread spectrum, the technology of choice for many of today’s digital, commercial cellular and PCs services
1992: The FCC reallocated spectrum at 2GHz for emerging digital mobile services.
1995: The first cellular system using digital CDMA technology was commercially launched by QUALCOMM. [5]
Understanding Radio Waves
Radio waves are the type of magnetic radiation with a wavelength in the electronic spectrum longer than infrared light. They travel at the speed of light similarly to all other radiations. Radio waves can be generated in two ways i.e. naturally and artificially. Naturally occurring radio waves are generated by the lightning or astronomical objects. Artificial generated radio waves which are generated by a radio transmitter and then received by a radio receiver. [3]
What are waves?
A wave is an oscillation or disturbance which is accompanied by a transfer of energy that travels through a medium (space or mass) or the repeating and periodic disturbance that moves through a medium (a substance that carries wave) from one location to another. A wave has a certain speed, frequency, amplitude and wavelength. The following mathematical model is used to show therelationship between them:
Speed= Frequency * Wavelength
Wavelength which is sometimes referred to as lambda is the distance measured from the point of one wave to the equivalent part of the next i.e. from the top of one peak to the next peak [1]
Frequency is the number of whole waves that pass a fixed point in a period of time. Speed refers to how fast the wave travels. Speed is measured in meters/second, the frequency is measured in cycles per seconds (or Hertz, Hz), and wavelength is measured in meters. Amplitude is the distance from the centre of the wave to the extreme of one of its peaks (the height of the wave).
The relationship between frequency, wavelength and amplitude are shown below
Fig 1.1 [13]
Propagation of Radio Waves
Propagation of radio waves is the behaviour of radio waves as they are propagated, from one point to another, or into various part of the atmosphere. In the developing telecommunication services, it is crucial first to understand the propagation of radio waves which are used in the transmission of information from one place to another. Radio propagation is affected by the change in weather e.g. change in water vapour and ionisation in the upper atmosphere which is influenced by the sun. [1]
Radio waves propagate in the space according to a different mechanism.(Flickenger, Aichele, & Fonda, 2006) Namely:
Free Space propagation
Reflection
Line of Sight Propagation
Transmission
Diffraction
Scattering
Wave Guiding
(i) Free Space Propagation (Line of Sight)
In this mechanism, a wave propagates without encountering any obstacles between the medium. The surface of the wave is the set of all points reached at a certain time after the moment wave is emitted from a homogenous medium. The attenuation in free space propagation comes from the scattering of energy which occurs as the wave propagates away from the transmitter. Free space attenuation is a function of the distance and the frequency. The excess attenuation compared to free space attenuation is defined as the difference between the path loss and free path attenuation.
(ii)Refraction
This is a phenomenon whereby vibrations or waves are reflected at a surface according to Snell-Descartes law. Snell-Descartes law is a formula used to describe the relationship between the angle of incidence and refraction when referring to light or other waves passing through a boundary between two different is, such as water, glass, or air. This phenomenon occurs when apropagating wave impinges upon a surface with large dimensions compared to the wavelength. It is found that the direction of an electromagnetic wave changes as it moves from an area of one refractive index to another. The angle of incidence and the angle of refraction are linked by Snell's Law that states:
n1 sin (theta 1) = n2 sin (theta 2)
For radio signals, there are comparatively few instances where the signals move abruptly from a region with one refractive index to a region with another. It is far more common for there to be comparatively gradual change. This causes the direction of the signal to bend rather than undergo an immediate change in direction.[12]
(iii)Transmission
This Phenomenon is the process whereby vibrations or waves propagates through a medium for instance vacuum, the air or an obstacle, without a change of frequency according to Snell-Descartes law. Various transmissions are used to propagate waves through amedium. In Regular transmission, the wave propagates through an object without diffusion. In Diffuse transmission, a phenomenon of diffusion occurs at a macroscopic scale independent of refraction laws. The Transmission coefficient is defined as the ratio between the transmitted energy flux and the incident energy flux.[1]
(iv)Diffraction
This phenomenon occurs when waves impinge upon an obstacle or an aperture with large dimension compared to the wavelength. This Phenomenon is one of the most important factors in the propagation of radio waves and results in disturbances affecting the propagation of these waves, for instance, the bending of the path around an obstacle or beam divergence. CITATION Fli06 \l 1033 ((Flickenger, 2006)
To understand the diffraction Huygens’s principle is applied. Huygens’s Principle states that “each point ...