Electronics/Signal Propagation

From Wikibooks, open books for an open world
Jump to navigation Jump to search


AC source alternates on a piece of wire. This creates an electric field that creates a magnetic field that creates an electric field. These waves are known as Electro-Magnetic waves, and are photons that travel through free space.

  • EMP (Electro-Magnetic Pulse): Generated by a nuclear blast, a high intensity blast of many frequencies. Shorts out electrical components.


Originally people thought that photons propagate through an aether wind. The aether was disproved by showing that it was not flowing from any direction even though the earth is moving.

My first tie in with other books. The idea is to have a short intro which motivates the other books so people will be interested in reading them.

In showing that the aether did not exist came the realization that light travels at the same speed regardless of how fast you are moving and that time is relative and events do not happen at the same time. With that knowledge came the famous E=MC2 equation, time travel, the secrets behind blackholes, and how gravity and energy warp time and space. Click Here to unlock these secrets of the universe.


You only need a quarter wavelength antenna to resolve a full wavelength. It is hard to resolve wavelengths of 200 meters. Use powerlines. Fractal antennas allow to compress the antenna size. As long as the antenna is long enough for a standing wave it does not matter how it is compressed.

  • aerials

Antenna Configurations[edit]


The earth behaves like a conductor. The ionosphere also behaves like a conductor. Both can reflect radio waves.

Further reading[edit]