Mobile phone signal jammers are mainly aimed at all kinds of examination rooms, schools, gas stations, churches, courts, libraries, conference centers (rooms), theaters, hospitals, governments, finance, prisons, public security, military areas and other places where the use of mobile phones is prohibited. It is understood that the mobile phone signal jammers on the market can limit the mobile phone signal beyond 500M meters from the transmitter, for example, some jammers have a radius of >20 meters. The shielding radius can be adjusted, and the coverage can reach more than 30 square meters. The mobile phone signal blocker can only shield the mobile phone signal without affecting other electronic equipment. Save electricity, the power is 12W--480W.
It looks like a WIFI transmitter, and the principle is actually the same.
When the mobile phone is working, it is within a certain frequency range. The mobile phone and the base station are connected by radio waves to complete the transmission of data and sound with a certain baud rate and modulation method.
The common mobile phone signal jammers on the market have the following frequencies: 869~894MHz; 925~960MHz; 1805~1880MHz and various styles of signal jammer 1900~1990MHz, etc. The working frequency bands are CDMA800, GSM900, DCS1800, and PCS1900. It can control the range of about 40 meters in diameter, using DC-DC converter input voltage, 5V output voltage.
After the listing of 3G signals, the working frequency bands of mobile phone signal jammers on the market today have also been upgraded from the previous four frequency bands to five frequency bands. On the basis of the previous four frequency bands, the frequency band of 2100 to 2200 has been added. It is used for shielding and interfere with the 3G band.
The cell phone jammer scans from the low-end frequency of the forward channel to the high-end frequency at a certain speed during the working process. The scanning speed can cause garbled interference in the message signal received by the mobile phone, and the mobile phone cannot detect the normal data sent from the base station, so that the mobile phone cannot establish a connection with the base station. The mobile phone is manifested as searching the network, no signal on the mobile phone, no service system, etc.