To put it simply, the frequency announced by the cell phone jammer disturbs the mobile phone to receive the frequency of the base station. The jammer and the base station are destined to be a competition connection. If the transmission power of the signal jammer is less than the channel that the base station transmits to the mobile phone in the environment at that time Power, then the jammer will not be able to shield, as long as the power of the signal jammer is greater than the power delivered by the base station to the mobile phone in order to effectively shield. Therefore, any shielding device used in different signal environments will show different shielding intervals, and mobile, China Unicom and telecommunications will be different, because the base station density, base station orientation and base station power built by these three operators cannot be the same of.
In other words, how many meters can be shielded by a mobile phone signal jammer is not only related to its own transmission power, but also to the distance between the base stations in the use environment (base stations are not limited to large-scale transmission towers built on the ground, but also buildings. The signal expansion antenna on the top and the signal expansion and spreading made in some buildings), another important factor is obstacles, if it is a metal material, it will be directly blocked; if it is a solid wall of reinforced concrete, it will be less attenuated after penetration 10 times; if it is a wood board or glass material, the attenuation after penetration is relatively small.
