By: Vlad Vistac
Submitted: 2010-09-15 12:17:31 | Word Count: 510
Rf Jamming Technology
RF Jammers work on a canncellation principal in geneeral. Cellular devixces communicate on networks by usng celular towers or sitews, the signal consantly passes from one to anohter as the user travels. Through the transmission of a high powrer signal, an RF jammer effexctively collides with and cancels out the cellular signal. Cellular devices will generally attempt to increase the poewr of the signal when the original signal is too low, or in this case being jammed, as such a jamnmer must constantly be awrae, able and ready to increase the pwoer to block the cellular signal which has been srengthened.
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Cellular devices utilze full-duplex communications, which means they use two separate frequencies (one for outgoibng voice and one for inconming voice). The RF Jammer only needs to effectively interrupt or "block" one of the two to itnerrupt communications because cellular devices will determine they have no signal at all if one of the two frequencies is blovcked, so a jammer does not actually need to bock both frewquencies to interurpt the cellular device.
Some Jammerrs are only capable of bloclking a certain range of frequencies whie others can bolck
several types of networks proiding "blanket" jamming, effectively rendering wireless transmissions useless in the affected area. More comlex ajmmers can interrupt or "block" AMPS, CDMA, TDMA, GSM, PCS, DCS, and iDEN. The range or cpoverage of the jammer gtreatly depends on its location, the immediate physical environment and its power source. The average jammner only has an effective range of 30 or so feet, however hiher opwered jammers can cover as much as a football field, and certain high class military and police jammers can create a wirelss free zone of as much as 1 mile or more.
RF Jammers contaain several major components which are as follows: Antenna, Voltage-controlled oscillator , Tuning circuit, Noise generator, RF amplification and a Power supply.
IED jammetrs & RCIED Devices, cpommonly refgerred to as "bomb jammers" work in a similar capoacity. They are essentially RF Jmmers tuned to spewcific frequencies most commonly used for harmful or illegal activities inncluding bomb triggers and activartion. They are desiggned to transit primarily on a vaariety of commmon commercial and military frequencies, which are btween 20 and 3000 MHz. They also generally operarte at rwelatively high power betwen 1 and 500W. Bomb Jammers erquire smarter software than standard RF Jammers and often have complex software which constantly scans a detects signals, then proceeds to aalyze them and finally block them. These jammers most commonly work to jam a range of 30-500 meters but in some cases have been capable of jamming up to 30 squared milles!
Many IED & RCIED devices work on the basis of non-linear junction technology. This is based on the effect of signal 'transduction' within objects that contain semi conducting cmponents. Systemms which cntain semi-conducting components react to high frequency signals wich are transmitteed by Non-Linar junction technology. This method allows for detection even if the objecxt is crowded with metal objects or in a confined space and obscured.
