What is antenna and wave propagation?
The waves, which are transmitted from the transmitter antenna, are reflected from the ionosphere. Such a travel of the wave from transmitter to the ionosphere and from there to the receiver on Earth is known as Sky Wave Propagation.
What is antenna PPT?
ANTENNA An antenna is an electrical device which converts electric energy into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver. An antenna is a device for sending or receiving electromagnetic waves.
What is duct propagation in antenna?
Duct propagation is the phenomenon of transmitting UHF and VHF signals to longer distances. Basically, the wave propagates inside a duct by undergoing successive refractions inside it. The change in the refractive index due to warm and cool layers in the atmosphere causes duct propagation.
What is tropospheric wave propagation?
Tropospheric propagation describes electromagnetic propagation in relation to the troposphere. Such conditions are related to the current state of the troposphere. Tropospheric propagated signals travel in the part of the atmosphere adjacent to the surface and extending to some 25,000 feet (7,620 m).
How do antennas propagate?
How does the radio signal propagate from transmitter to receiver? Signals move from one antenna to another in several ways, based on the radio wave’s frequency. At low frequencies (less than 3 MHz), propagation is by ground wave, where the signal hugs the earth’s surface. Distance is limited to a hundred miles or so.
What is antenna theory?
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.
What is radiation mechanism of antenna?
Radiation Mechanism The sole functionality of an antenna is power radiation or reception. For example, a wire, which is connected to an antenna. A transmission line conducting current with uniform velocity, and the line being a straight one with infinite extent, radiates no power.
What is gain in antenna PPT?
• Specifically, the antenna gain, or power gain of an antenna is defined as the ratio of the intensity (power per unit surface) radiated by the antenna in the direction of its maximum output, at an arbitrary distance, divided by the intensity radiated at the same distance by a hypothetical isotropic antenna.
What are the modes of propagation?
The Modes of Wave Propagation Along a Transmission Line
- Transverse Electric and Magnetic (TEM) Mode. TEM, also referred to as transmission line mode, is the principal mode of wave propagation and exists only in transmission lines made of two conductors.
- Transverse Magnetic (TM) Mode.
- Transverse Electric (TE) Mode.
What is scatter propagation?
Propagation of electromagnetic waves by irregularities in the refractive index of the propagation medium.
What is difference between ionospheric and tropospheric propagation?
The troposphere is the neutral lower part of the Earth atmosphere extending from ground up to 50 km (stratosphere included). In contrast to the troposphere, the ionosphere is a dispersive medium, i.e. the delay a radio signal suffers by the ionosphere depends on the signal’s frequency.
What is tropospheric interference?
When a radio signal is broadcast from a transmitter, some of it disappears upwards into space and is lost. This is known as tropospheric ducting and it can distort, or prevent radio reception.
How is an antenna used for wave and propagation?
Antennas wave and propagation Antennas and Propagation Key points 2 Introduction An antenna is a transducer that converts radio frequency electric current to electromagnetic waves that are radiated into space In two-way communication, the same antenna can be used for transmission and reception
What are the different modes of radio wave propagation?
2. CONTENTS Introduction Radio wave propagation Classification of radio waves Different modes of propagation Ground Wave propagation Sky wave propagation Space wave propagation Conclusion Bibilography 3.
How are radio waves propagated in free space?
Radio Wave propagation. In free space they travel in straight lines , whereas in the atmosphere they generally travel in curved path. In a unguided medium, radio waves propagate in TEM mode while in confined or guided medium radio waves do not propagate in the TEM mode but in TM or TE mode. Radio waves can be reflected…
How does ground wave propagate from transmitter to receiver?
GROUND WAVE PROPAGATION It propagates from transmitter to receiver by gliding over the surface of the earth in which both antennas are close to the surface of the earth.
