There are a number of basic properties of electromagnetic waves, or any repetitive waves for that matter that are particularly important.įrequency, wavelength and speed are three key parameters for any electromagnetic wave. Electromagnetic wave wavelength, frequency & velocity In fact some of the first experiments with radio waves proved these facts, and they were used to establish a link between radio waves and light rays. Like other forms of electromagnetic wave, radio signals can be reflected, refracted and undergo diffraction. It is generated as a result of the current flow in the antenna. The other component, namely the magnetic field is at right angles to the electric field and hence it is at right angles to the plane of the antenna.
This measure is often used in measuring the intensity of an electromagnetic wave at a particular point. volts per metre, and this is known as the field strength. This electric field is measured in terms of the change of potential over a given distance, e.g. The lines of force in the electric field run along the same axis as the antenna, but spreading out as they move away from it. The electric component of the wave results from the voltage changes that occur as the antenna element is excited by the alternating waveform. It is useful to see where the different elements of the wave emanate from to gain a more complete understanding of electromagnetic waves. The planes of the fields are at right angles to each other and to the direction in which the wave is travelling. The radiation is made from electric and magnetic components that are inseparable.
Electromagnetic waves – e/m radiation basicsĮlectromagnetic waves or e/m radiation has two constituents. There are also some media through which they can travel but are attenuated. However conductive media like metals form a barrier through which they do not travel. This is the same form of radiation as light, ultra-violet, infra-red, etc., differing only in the wavelength or frequency of the radiation.Įlectromagnetic radiation can travel through many forms of medium. Radio signals exist as a form of electromagnetic wave. Modes of propagation, Structure of atmosphere, Ground wave propagation, Tropospheric propagation, Duct propagation, Troposcatter propagation, Flat earth and Curved earth concept Sky wave propagation – Virtual height, critical frequency, Maximum usable frequency – Skip distance, Fading, Multi hop propagation.Electromagnetic Waves: e/m radiation Electromagnetic waves or E/M radiation are the basic wave type that are used for radio waves, light and many more forms of radiation.Įlectromagnetic waves Radio spectrum Polarisation Modern antennas- Reconfigurable antenna, Active antenna, Dielectric antennas, Electronic band gap structure and applications, Antenna Measurements-Test Ranges, Measurement of Gain, Radiation pattern, Polarization, VSWR Principle of frequency independent antennas –Spiral antenna, Helical antenna, Log periodic. N element linear array, Pattern multiplication, Broadside and End fire array – Concept of Phased arrays, Adaptive array, Basic principle of antenna Synthesis-Binomial array Radiation from rectangular apertures, Uniform and Tapered aperture, Horn antenna, Reflector antenna, Aperture blockage, Feeding structures, Slot antennas ,Microstrip antennas – Radiation mechanism – Application ,Numerical tool for antenna analysis Matching – Baluns, Polarization mismatch, Antenna noise temperature, Radiation from oscillating dipole, Half wave dipole. Definition of antenna parameters – Gain, Directivity, Effective aperture, Radiation Resistance, Band width, Beam width, Input Impedance.
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