Where do raio waves come from?

Question

Where do raio waves come from?

Answer 1

When alternating current flows in a conductor it has an invisible sheath of magnetic lines too. The electric & magnetic fields produced thus, constitute directed Electro-Magnetic power. Power is product of the two fields. Fields propagating thus, have a ratio (in fact it is the square root of ratio of Electric to Magnetic field strengths) based on geometry of the conductor, called Impedance. Impedance is a character of the medium (or the conductor and surrounding dielectric substance). When there is an abrupt transition from medium to medium the E (Electric field) & H (magnetic field) cannot support the smooth power flow and some of it gets scattered into the surrounding dielectric (non-coducting) medium as waves. This is the origin of Radio waves.

Any isolated conductor (metal) experiences the waves and the electrons or charges of it move sympathetically in resonance with the impinging waves. So, this current can be picked up (constituting electron flow in the metal).

Both the conductors, one from which the radio waves exit and the other which picks them, are the transmitiing and receiving antennas. By deliberately creating an obstruction in a metal (conductor) current flow pattern the current waves can be radiated as waves into the surrounding environment.

If the frequency of alternations are to be increased, it can only be possible by replacing the conductor rods of smaller and smaller lengths with linear dimensions of wavelengths to be generated or transmitted. Since product of wavelength and frequency (of alternations) is the speed of propogation that is constant, wavelength and frequency are inversely related. One increase in direct proportion to the other decreasing.

If the wavelengths reach molecular or even atomic dimensions, certain materials or crystals can be induced (by engineering design) to generate such waves. For sub-millimeter wavelengths (approaching frequencies of million million cycles per second) the atomic processes that generate are nothing but the transitions of electrons of atoms, from one orbit to another. in other words it is 'visible (coloured) light'. All these waves normally travel at same speeds in space and is the velocity of light, irrespective of whether these are radio waves, light waves or X-rays.