Regd. No. 10804571
Roll no. RB6803A16
Electronics Department, Lovely Professional University
Abstract— the project is enlightening us about the characteristics and properties of electromagnetic wave .It also include radar, how does it works, its components and application of EM Wave in radar.
1. Electromagnetic Waves
Electromagnetic waves are composed of oscillating electric and magnetic fields at right angles to each other and both are perpendicular to the direction of propagation of the wave. Electromagnetic waves differ in wavelength. Fig1. Propagation of em wave
In an electronegative wave the electric field E(vector) and the Magnetic field B(vector) oscillate perpendicular to each other and both are perpendicular to direction of propagation of wave. The E and B fields, along with being perpendicular to each other, are perpendicular to the direction the wave travels, meaning that an electromagnetic wave is a transverse wave. Electromagnetic waves were first postulated by James Clerk Maxwell and subsequently confirmed by Heinrich Hertz. Maxwell derived a wave form of the electric and magnetic equations, revealing the wave-like nature of electric and magnetic fields, and their symmetry. Because the speed of EM waves predicted by the wave equation coincided with the measured speed of light, Maxwell concluded that light itself is an EM wave. According to Maxwell's equations, a spatially-varying electric field generates a time-varying magnetic field and vice versa. Therefore, as an oscillating electric field generates an oscillating magnetic field, the magnetic field in turn generates an oscillating electric field, and so on. These oscillating fields together form an electromagnetic wave. 2. Properties of electromagnetic waves
1) Electromagnetic waves are propagated by oscillating electric and magnetic fields oscillating at right angles to each other. 2) Electromagnetic waves travel with a constant velocity of 3 x 108 ms-1 in vacuum. 3) Electromagnetic waves are not deflected by electric or magnetic field. 4) Electromagnetic waves can show interference or diffraction. 5) Electromagnetic waves are transverse waves.
6) Electromagnetic waves may be polarized.
7) Electromagnetic waves need no medium of propagation. The energy from the sun is received by the earth through electromagnetic waves. 8) The wavelength (λ) and the frequency (v) of electromagnetic wave is related as c = v λ = ω/k
3. Characteristics of electromagnetic waves
Electromagnetic waves are transverse waves, similar to water waves in the ocean or the waves seen on a guitar string. This is as opposed to the compression waves of sound. As all waves have amplitude, wavelength, velocity and frequency. 3.1 Amplitude
The amplitude of electromagnetic waves relates to its intensity or brightness (as in the case of visible light). With visible light, the brightness is usually measured in lumens. With other wavelengths the intensity of the radiation, which is power per unit area or watts per square meter is used. The square of the amplitude of a wave is the intensity. 3.2 Wavelength
The wavelengths of electromagnetic waves go from extremely long to extremely short and everything in between. The wavelengths determine how matter responds to the electromagnetic wave, and those characteristics determine the name we give that particular group of wavelengths. 3.3 Velocity
The velocity of electromagnetic waves in a vacuum is approximately 186,000 miles per second or 300,000 kilometers per second, the same as the speed of light. When these waves pass through matter, they slow down slightly, according to their wavelength. 3.4 Frequency
The frequency of any waveform equals the velocity divided by the wavelength. The units of measurement are in cycles per second or Hertz. c =...