Cell phone signal jammers have become standard equipment in examination rooms. Not only for middle school or university entrance exams, such as postgraduate exams, civil service exams and various qualification certificate exams, cell phone signal blocking devices are also required to prevent candidates from contacting the outside world through wireless signals. Now the mobile phone signal jammer is a full-band, which can block all G3G4G signals and 2.4GWIFI signals and Bluetooth signals of all three operators of China Mobile, China Unicom and China Telecom. The principle is to interfere with the frequency of mobile phone receiving base stations and wireless routers through its own frequency, thereby achieving the purpose of shielding them.

Principle: Within a certain frequency range, mobile phones and base stations are connected through radio electromagnetic waves, and data and sound transmission are completed with a certain baud rate and modulation method. The communication principle of the mobile phone signal jammer is that the 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 speed of the scan creates random code interference in the phone's reception signal. The phone cannot detect normal data sent from the base station, so the phone cannot establish a connection with the base station. Mobile phones show symptoms such as searching the network, no signal, and no service system. Because we know that wireless communication communicates through electromagnetic waves. The functional properties of electromagnetic waves depend on their frequency.

Our mobile phones must emit electromagnetic waves that meet the requirements when they are connected to the base stations of our communication operators. Different communication systems use different frequencies so everyone is safe and does not interfere with each other. The basic principle of cell phone jamming devices is to emit the same radio frequency signals as cell phones. Due to the same frequency, mobile phones cannot distinguish which signal is the traditional base station signal, thereby achieving "interference". As long as there is a machine on the same frequency as the phone, it will send out a lot of information when the base station tries to connect to the phone. "noise".

You will find that the signal on your phone cannot be recognized, so you will refuse to communicate with the phone. In the early days, signal jammers only blocked one set of frequencies, such as 2G, however, complex jammers can block multiple types of networks at the same time, such as 2-3-4-5G. So, how to achieve this multi-network interference? it's actually really easy. In other words, the interference bands of these three signals are repeated in a cyclic manner, covering the interference bands of these three signals simultaneously. The interval of this cycle is so small that the phone has no chance to talk, but can only sit down and quietly make a brick. Covering 2/3/4/5G, what about Bluetooth and wifi? It's okay, it's easy to do. Jammers have evolved again, Bluetooth and Wi-Fi have evolved again, adding frequency bands within the scanning range, allowing complete coverage of several common communication methods in society.

Bluetooth, Wi-Fi Many people don’t understand the difference between mobile data. This appears to be wireless communication technology. In fact, the main difference between them is the frequency band. In mobile communication technology, 2G mainly works in the 900-1700MHz frequency band, 3G works in the 1900-2100MHz frequency band, 4G works in the 2300-2500MHz frequency band, and 5G works in the 3400-3600MHz frequency band.