Tuesday, June 8, 2010

UNDERSTANDING RF

UNDERSTANDING RF


Radio frequency (RF) – Radio Frequency is the area (or band) of the electromagnetic spectrum where most radio communication takes place.



The signal can be thought of as a wave that spreads out from its source (the antenna). It is often referred to as an electromagnetic wave that is made up of linked electric and magnetic components. The radiofrequency (RF) part of the electromagnetic spectrum includes electromagnatic waves produced by television and radio transmitters (including base stations) and microwaves. The electric and magnetic components that form the electromagnetic wave can be referred to as radiofrequency fields.

From "Radiation, Mobile Phones, Base Stations and Your Health" by Prof Ng Kwan-Hoong, Universiy of Malaya.

Radio Frequency and Health Talk by Prof Ng Kwan Hoong.


It is established that RF do not have sufficient energy to damage cell structures.

Thus, the RF energy is considered as "non-ionizing". Non-ionizing radiation (NIR) is a general term for certain parts of the electromagnetic spectrum with energies that are too weak to break atomic bonds. They include extremely low frequency (ELF) fields, radiofrequency and microwave (RF/MW) fields, infrared radiation, visible light and ultraviolet (UV) radiation.

As non-ionizing radiation cannot break chemical bonds, there is no similarity between the biological effects of non-ionizing radiation and ionizing radiation (such as x-rays).

At the extremely high frequencies of electromagnetic spectrum (such as xrays
and gamma rays), electromagnetic particles (photons) have sufficient energy to cause ionization (create positive and negative electrically charged atoms or parts of molecules) by breaking the atomic bonds that hold molecules in cells together. This is how x-rays damage the genetic material of cells, potentially leading to cancer or birth defects.

Even at high intensity, NIR cannot cause ionization in a biological system.

Compiled from: Ministry of Health Malaysia - Guidance To Safety and Health Aspects Of Base Stations and Mobile Phones.



TERMINOLOGIES

EMF – Electromagnetic Field are invisible lines of force surrounding any electrical wire or device. They consist of two components — the electric field, which is the result of voltage, and the magnetic field, which is the result of current flow.

EM - The electromagnetic (EM) spectrum is the range of all possible electromagnetic radiation frequencies.The "electromagnetic spectrum" (usually just spectrum) of an object is the characteristic distribution of electromagnetic radiation from that particular object.

Electromagnetic radiation - takes the form of self-propagatingwaves in a vacuum or in matter. EM radiation has an electric and magnetic field component which oscillate in phase perpendicular to each other and to the direction of energy propagation. Electromagnetic radiation is classified into types according to the frequency of the wave, these types include (in order of increasing frequency): radio waves, microwaves, terahertz radiation, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays.

Radio waves - are electromagnetic waves occurring on the radio frequency portion of the electromagnetic spectrum. A common use is to transport information through the atmosphere or outer space without wires.

Non-ionizing radiation (NIR) - refers to any type of electromagnetic radiation that does not carry enough energy per quantum to ionize atoms or molecules — that is, to completely remove an electron from an atom or molecule. Near ultraviolet, visible light, infrared, microwave, radio waves, low frequency RF and static fields are all examples of non-ionizing radiation.

Ionizing Radiation - Radiation that carries more than 1216 kJ/mol of energy. Enough energy per quantum to ionize atoms or molecules e.g.UVB rays (higher end of the UV spectrum), x-rays, gamma rays, cosmic rays.


THE ELECTROMAGNETIC SPECTRUM

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