Carabinieri’s Aurisina Radio mobile phone was checked and found that a luxury car was carrying about 4,000 euros worth of designer jackets, shoes and T-shirts. The two men were driving in 62 and 54-year-old luxury cars, respectively. And Prosecco station. The inspection revealed that clothes in a shop in the Udi inland shopping mall and a shop in the province of Venice were the objects of various thefts. After Carabinieri was rebuilt, the 62-year-old man entered the store with a small bag containing a “cell phone jammer” (buy signal jammer). The anti-theft lock hidden in the bag lining can be avoided). Then, with the help of his accomplices, he chose what he wanted to steal and walked out undisturbed. When searching for the vehicle, almost all anti-theft devices except clothes were installed, jammers were found, and the anti-theft plate with magnets, two Swiss knives and 1,500 euros in cash were removed. As a result, these products were sold illegally.
Through the above events, various misunderstandings when using mobile phone jammers are discussed, as follows:
Misunderstanding 1: Use cell phone jammers to commit crimes
The use of jammers in man-made illegal and criminal activities is strictly prohibited. B. Avoid finding shopping malls when disturbed by jammers.
Misunderstanding 2: The stronger the performance of the mobile phone signal shielding device, the wider the shielding effect
In fact, this is not entirely correct. Many manufacturers use the status quo: ordinary users may not see the actual performance, and deliberately exaggerated the openness of the shielding performance, resulting in the device’s rated performance indicators losing the reference value. For large-area shielding systems, shielding technology is the decisive factor for shielding effectiveness. The benefits of advanced shielding technology are far greater than the output power factor of shielding equipment.
Misunderstanding 3: Use directional antennas to avoid external influences
This is also wrong, because the directional antenna covers the main lobe, side lobes and side lobes. The main lobe coverage angle is defined as the coverage angle of the mobile phone signal shielding when the external power of the main lobe drops by 3 dB. In other words, the radiation intensity of the side and back of the directional antenna is only much lower than the radiation intensity of the main lobe. Therefore, if the room near the antenna is shielded, the reflection of the shielded building will still cause external interference. In addition, if it is used improperly, it will cause upstream interference, and the interference area will be larger. Therefore, whether the equipment technology can meet the conditions, the application of the antenna and the debugging of the system are more meaningful than the use of a directional antenna.
Misunderstanding 4: Signal shielding distance is a difficult indicator
In fact, the distance is not an absolute value. It is related to the strength and quality of the spatial signal. In short, distance is meaningless. If under the same shielding performance, the distance of the weak point is 100 meters to 70 decibels, the distance of the strong 52 decibels is only 12.5 meters. The shielding distance depends on the antenna gain. The same Power Shielding host uses antennas with different gains, and the distances vary greatly. For example, an antenna with a gain of 16 dB is 100 meters away, and an antenna with a gain of 4 dB is 25 meters away.