At present, signal jammers are widely used in conference rooms, schools and detention centers, which can be said to be widely used, mainly to shield the signals of mobile communication equipment. Nowadays, with a mobile phone, the information sent can be spread to any corner of the world instantly through communication software and network. The speed of information transmission is so fast. However, compared with the above places, sometimes it does not need a mobile phone, so it can use shielding devices. The signal jammer interferes the signal received by the mobile phone according to the communication principle of the mobile phone, so as to shield the mobile phone signal.

As one of the most important communication devices, mobile phones can also receive signals from nearby base stations before sending information to the outside world, so that the opposite party can transmit its own signals. The information is mainly transmitted by the electromagnetic wave, and the wireless signal frequency band used by the mobile phone is closely related to each operator. The current signal shielding devices are all full band interference devices, which can effectively shield all bands of the three major operators when working. When the signal jammer is working, it scans from low frequency band to high frequency band at a certain speed of waveform, and generates multiple wireless signals to cover all frequency band signals of the operator, finally forming a shielding area to achieve the desired effect.