Little knowledge that signal jammers must know
I believe everyone is familiar with mobile phone signal jammers. In recent years, various jammers have emerged on the market. Everyone claims that their mobile phone wifi jammers are particularly good, and the material is full of moisture, which makes you confused. Good or bad, so what should we know about jammers?
The first point is that the greater the power of the mobile phone signal shielding device, the farther the shielding effect will be. In fact, this is not entirely correct. Many manufacturers use the current situation that ordinary users cannot detect the actual power, and deliberately exaggerate the openness of the shielding power. Cause the nominal power index of the equipment to lose its reference value. For large-scale shielding systems, shielding skills are the decisive factor affecting the shielding effect. The advantages brought by advanced shielding technology are far greater than the output power factor of the shielding equipment. The second point is that directional antennas are used to avoid external interference. This is also incorrect, since the directional antenna masks the main lobe, side lobes and back lobes. The main lobe cover angle is defined as the shielding angle of the mobile phone signal when the external power of the main lobe drops by 3dB. That is to say, the radiation intensity on the sides and back of the directional antenna is only much lower than the main lobe. Therefore, if the space closer to the antenna is still relatively shielded, the reflection of the shielded building will still cause external interference. In addition, if used improperly, it will cause upstream interference, and the scope of the interference will be larger. Therefore, whether the equipment technology meets the conditions, the application of the antenna, and the debugging of the system are far more meaningful than whether to use a directional antenna. The third point is that we all think that the shielding distance of mobile phone signals is a hard indicator. Actually, the interval is not an absolute value. It has to do with the strength and quality of the signal in space. Simply put, intervals are meaningless. The same shielding power, if the distance is 100 meters - 70 decibels in the weaker place, then only 12.5 meters in the strong - 52 decibels. Shield spacing is related to antenna gain. The same power shield host uses different gain antennas, and their spacing will also be very different. For example, antennas with a gain of 16 db are separated by 100 meters, and antennas with a gain of 4 dB are separated by only 25 meters. To sum up, when choosing a mobile phone signal, it is necessary to combine the actual situation of the site environment, not only to trust the hearing, but also to test it in person.