The jammer can make normal reception of radio wave signals difficult or even impossible (e.g. radio, television, mobile phone, GPS, etc.). The jammer transmits the same radio waves as the disturbed transmitter, so normal data sent by the base station cannot be recognized.
The most popular jammers on the market are cell phone jammer, GPS jammers, WiFi jammers, and drone jammers, among which cell phone jammers and GPS jammer are the most common. The cell phone interference prevents the cell phone from recognizing the normal data sent from the base station and the cell phone cannot connect to the base station. At this time, the cellular phone mainly has the network browsing phenomenon, no signal from the cellular phone and no service system.
GPS jammers are mainly used for long-distance bus drivers and some people who do not want to be tracked with GPS signals. GPS interference can effectively prevent GPS satellite positioning and tracking, only interfere with GPS signals, does not affect cell phone answering, small size, light weight, usually equipped with a car charger, easy to carry.
Jammer applications are very common in the military sector. This device makes it difficult for others to use a specific frequency band or the entire frequency band. It has also become a noise nuisance and has long been used as part of electronic countermeasures, such as on cars with intelligence jammers. It protects the front of the car and prevents attacks such as remote-controlled bombs.
Jammers are sometimes used in some civil areas. For example, jamming devices are installed in German prisons and youth detention centers in order to disrupt or suppress the frequency of unauthorized radio communications in the vicinity and thus reduce drug trafficking and prison breakouts. In August 2016, mobile interference telephones were tested in St. Pölten, Austria and were successful. The results show that the test can only prevent the connection between prisoners and does not interfere with mobile communication outdoors. According to statistics, around 60 to 70 cell phones are checked in prison every month across Austria.
The jammer also prevents remote control of bombs. In 2007, the Pakistani opposition leader Benazir Bhutto survived an attack because jammers placed on the bus blocked the explosion of remote-controlled bombs.
During the Iraq war, the Iraqis used GPS jammers to jam the GPS navigational data, rendering the U.S. cruise missiles, bombers, etc. no targets. During the sandstorm, Americans relied on GPS and aerial surveillance radars, and the Iraqis actually used GPS jammers, forcing the Americans to shut down this strategically important tool.
Jammers are becoming more and more common in life, but they must not be used illegally.