We can compare a mobile phone to a radio for the time being. The radio often chuckles or the channel is simply messed up and cannot be heard. This means that the signal is disturbed. Since the radio can be disturbed, the mobile phone is the same. And interfere with some devices. The communication principle of the mobile phone jammer, the mobile cell phone jammer scans from the low end frequency of the forward channel to the high end at a certain speed during the working process. This 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 a search network, no signal, no service system and other phenomena.
Compared with the mobile phone jammer, the appearance is not particularly important, but the structure of the setting is different. From the appearance, mobile phone signal jammers can be divided into external antennas and internal antennas. The antenna and power supply of the built-in antenna are all installed in the case, occupying a small area, and there is no need to connect the antenna before use, which is more convenient. Therefore, the first choice for the mobile phone signal jammer in the examination room is the signal jammer with the built-in antenna. In addition, the appearance of the mobile phone jammer also needs to consider the examinee’s visual experience, try to make the appearance simple, the color is not abrupt, and not let the examinee have visual pressure.