The mobile phone signal shielding experience for the college entrance examination is believed to have been devastated. Even those who have not experienced it should also know about the mobile phone shielding device in the college entrance examination examination room. The mobile phone signal shielding device is actually such an item. What is a shielding instrument and where can it be used?
The cell phone jammer device is mainly forbidden for various examination rooms, colleges, gas stations, main churches, courts, public libraries, international conference centers (rooms), cinemas, hospital outpatient clinics, government departments, financial industries, prison cells, public security, and defense centers. Application mobile phone venue. According to statistics, the shielding devices on the sales market today can limit mobile phone signals that are 500M meters away from the launching station and have a half-length of >20 meters. The shielding is semi-adjustable, it only shields the mobile phone signal, and does not cause harm to other electronic products. Save energy, the output power is 20W-480w.
For the basic principle of this kind of communication, the mobile phone shielding instrument scans from the low-end frequency to the high-end at a certain rate during the whole working process. When the mobile phone works, it is within a certain frequency range, and the mobile phone and the communication base station are connected by wave, and the data information and sound transmission are carried out at a certain baud rate and deployment method. The scanning rate can produce garbled effects in the message signal received by the mobile phone, and the data information transmitted from the communication base station cannot be checked on the mobile phone, so that the mobile phone cannot establish a connection with the communication base station. The main manifestations on the mobile phone are that the network cannot be searched, the signal is poor, and the service system is not available.
At present, with the rapid progress of the Internet, the development trend of mobile phone shielding devices is also upgrading, and the cost is very low. As long as the frequency band of the known network is included in the disturbing team, all radio communications can be shielded and destroyed.