Miyerkules, Disyembre 4, 2013

Electromagnetic Wave Propagation Theory



Electromagnetic Wave Propagation Theory

Agenda:

Provides with the composition of the ionosphere, the effect that the ionosphere and ground has on radio waves and the modes of electromagnetic wave propagation.

Radio Waves Propagation Modes:

Radio propagation is a term used to explain how Electromagnetic Radiation (EMR) behaves when transmitted through various mediums. EMR is more commonly referred to as Radio Frequency (RF) or radio waves. The movement of radio waves through the earth’s atmosphere.The behaviour of electromagnetic waves.

Radio waves are propagated through space in all directions. When the correct antenna and orientation are selected, the intensity of radiated power can be increased in a desired direction, while decreasing the amount radiated in unwanted directions. The amount of power arriving at the receiving end will depend on the antenna chosen and the characteristics of the path through which the radio waves travel. Radio waves follow some basic rules:

Basic System.
The basic radio system (equipment portion) is composed of:
A transmitter -             The transmitter produces an electromagnetic wave at a specific frequency.
A transmission line -    The line feeds the radio frequency (RF) energy being produced by the transmitter to the transmit antenna.
A transmit antenna -    The antenna radiates the RF energy into the atmosphere.
A receive antenna -      The receive antenna collects a portion of the energy radiated by the transmit antenna.
A transmission line -    This line passes the captured energy to the Receiver (receive).  
A receiver -                 The receiver converts the RF energy to a usable form.             (ex. Audio, pictures, etc.)