The portable jammer may make it difficult or even impossible to receive radio wave signals normally (e.g. radio, television, cell phone, GPS, etc.). The jammer transmits the same radio waves as the jammed transmitter, so that normal data sent by the base station cannot be recognized.
The most popular jammers on the market are cell phone jammers, GPS jammers, WiFi jammers and drone jammers, among which cell phone jammers and GPS jammers are the most common. The cellphone interference prevents the cellphone from recognizing the normal data sent from the base station and the cellphone cannot connect to the base station. At this time, the cellular phone mainly has the phenomenon of searching the network, 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, has no effect on cell phone responses, small size, light weight, usually equipped with a car charger, easy to carry.
Jammer applications are very common in the military. 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, for example for cars with secret service jammers. It protects the front of the car and prevents attacks such as remote-controlled bombs.
Jammers are sometimes used in some civilian areas. For example, jamming devices are installed in German prisons and juvenile detention centers in order to disrupt or suppress the frequency of unauthorized radio connections in the vicinity, thereby reducing drug trafficking and the outbreak of prisons. In August 2016, mobile interference phones 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 every month in prison in Austria.
The jammer also prevents remote control of bombs. In 2007, Pakistani opposition leader Benazir Bhutto survived an attack because the jammers placed on the bus blocked the explosion of remote-controlled bombs.
During the Iraq war, Iraqis used GPS jammers to disrupt GPS navigation data, preventing the US cruise missiles, bombers, etc. from targeting. During the sandstorm, Americans rely on GPS and air surveillance radar, and Iraqis have actually used GPS jammers, which has forced Americans to turn off this strategically important tool.
Jammers are becoming increasingly common in life, but must not be used illegally.