Transcription of Chapter 13: Wave Propagation
{{id}} {{{paragraph}}}
Example: bankruptcy
Chapter 13: Wave Propagation
Chapter 13: Wave PropagationEET-223: RF Communication CircuitsWalter LaraElectrical to electromagnetic Conversion Since the atmosphere is not a conductor of electrons (instead a good insulator), electrical energy must be converted into another form of energy for transmission It is converted into electromagnetic energy by a transmitting antenna and back into electrical energy by a receiving antenna Technically speaking an antenna is a transducer Usable radio wave are at ~ x 104Hz up to 3 x 1011Hz A light bulb also converts electrical energy into electromagnetic energy: light at ~5 x 1014 HzElectromagnetic Waves In free space, an oscillating electric field creates and oscillating magnetic field , which creates an oscillating electric field , and so on. These two fields contain energy: In circuits the energy is returned to the circuit when the fields collapse In a radio transmitter the antenna is designed not to allow the energy to collapse back into the circuit, but instead to be radiated (or set free) into the form of an electromagnetic (EM) wave (aka radio wave) An EM wave electric field , magnetic field and direction of Propagation are mutually orthogonal (see Fig 13-1)Figure 13-1 electromagnetic An
Electromagnetic Waves •In free space, an oscillating electric field creates and oscillating magnetic field, which creates an oscillating electric field, and so on. •These two fields contain energy: –In circuits the energy is returned to the circuit when the fields collapse –In a radio transmitter the antenna is designed not to allow the energy to collapse back into the circuit, but ...
Loading..
Tags:
Information
Domain:
Source:
Link to this page:
Please notify us if you found a problem with this document: