The interference power of the shield is certain, and the shielding radius of the non-blocking space is determined by the path attenuation and the receiving base station signal level. On mobile network to realize mobile phone cell phone jammer, must ensure that the jammer signal of the field strength is greater than the implementation of mobile signal interference area of field intensity, interfere with the location as close to the base station, the stronger the field intensity, effective jamming area is smaller, conversely, the farther from the base station location, field strength is weak, the greater the effective jamming area.
The Army points to newly developed algorithms that would enable a missile to detect jammers and determine their location, such as Multiple Signal Classification (MUSIC). These algorithms focus on unique characteristics of jammers. “For example, trackable interference, aka spoofers, likely generate the entire GPS-like constellation and transmit from a common point; thus, these signals generate exogenous constellation-wide delay (i.e., in a bend-pipe versus line-of-sight RF transmission). Other defining characteristics of a malicious interference may include increased energy (i.e., jammers), clock drift/offset coloring, inter-satellite interference, etc.”
According to the above working principle, the cell phone jammer is generally composed of power supply, electronic scanning control unit, segmented radio frequency module unit, amplifier unit, transmitting antenna unit, etc. Signal generator to generate scanning signal after inverter into the oscillator to the mobile communication frequency modulation, through the power amplifier power amplifier and voltage regulator tube control, enlarged the frequency sweep signal in the form of radio waves launched into the air. Because of the frequency sweep signal formed in mobile phone message reception garbled interference (increase the proportion of noise noise signals to equipment threshold), mobile phone can’t receive normal data from the base station, cell phone can’t establish normal connection with base station, enabling from the base station communications network. The mobile phone shows no signal, no service system and other phenomena in the search network to achieve the blocking effect.
It is believed that a one-kilowatt portable signal jammer can block a GPS receiver from as far away as 80 kilometers. Russia has several powerful military units in the vicinity of the border, among them the 200th Independent Motor Rifle Brigde in Pechenga.