For mobile phone safety issues, scientists in mobile communication through in-depth analysis of the mechanism of using electromagnetic emission technology, through trial and error, and finally found the effective ways of prevent leak and blocking signal, developed cell phone signal jammer successfully. Cell phone jammer, the use of advanced modern digital communication technology and electronic technology, military anti-jamming develops and produces new intelligent digital integrated system, the digital modulation control mode, through wireless technology control area wireless communication equipment normal communication.

Everyone knows in the same position, different indoor, different time may have great changes of mobile phone signal. According to scientists practical experience, it was found that the change of the value 10dbm can reach the highest power, with the minimum power are 10 times, according to the radio signal transmission distances every doubled, 6dbm power decrease in intensity, 10dbm changes and increase must power equipment may increase redundant, double. Otherwise it will cause the intermittent during operation. In the year of the 24 hours of continuous operation circumstance, this kind of circumstance is not allowed on the high requirements, special occasions such as protracted design according to the highest demand commonly when the signal and power redundancy design, high reliability, confidential for ensuring stable, shielding the effective demand is strictly jamming.

Conversely, in general, only quiet civil in a common conditions can make screen area or shielding rate more than 98%, its operation time, generally does not exceed 8 hours of continuous operation, not more than 1,500 hours. Regardless of how changes in the external environment, the cell phone jammer does not necessarily ensure signal of every corner of the screen, that is the basic Cell phone jamming.