Every year during the middle school entrance examination, there will be mobile phone calls dropped around the school, slow Internet access and other network problems, which is because the school has turned on mobile phone jammers. If we think of mobile phones as hand-held two-way radios, radios can be interfered with, and mobile phones are no exception. Just like any radio, cell phone signals can get jammed.
The principle of mobile phone signal blocker is that in a certain frequency range, the mobile phone and the base station are connected by radio waves to complete the transmission of data and sound at a certain baud rate and modulation. According to the communication principle mentioned above, the mask scans from the low frequency of the forward channel to the high frequency at a certain speed during operation.
The scanning speed can cause garbled interference in the reception message signal of 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. Mobile phone search network, no signal, ineffective labor system and other phenomena. Eventually, the phone has no signal, can not receive text messages, phone calls.
Wireless communication is the application of electromagnetic waves to stop communication. The functional properties of electromagnetic waves are determined by their frequency. Our phones must emit the electromagnetic waves that are required to connect to our carrier's base station. The basic principle of mobile phone interference equipment is to transmit the same radio frequency as the mobile phone, because of the same frequency, the mobile phone can not tell which signal is the right base station signal, so as to complete the "interference". So how is this multi-network interference accomplished? It's actually very simple. That is, in a circular way, the interference band corresponding to the three signals is repeatedly played, and the three bands are covered at one time, and the distance of this cycle is very small, so that the mobile phone can only sit down obediently without speaking.
At present, the main principle of signal shielding and signal jammer is to emit grand noise in the frequency band used by mobile phones, disrupting the reception and transmission of normal signals of mobile phones. This small object is not only used to avoid cheating during exams, but also to avoid fear attacks in politics and the military.
