Although a mobile phone is a wireless communication device used wherever it goes, there is also an invisible line dragging it, which is the mobile phone base station. Whether a mobile phone makes or receives a call, the first step is to establish a connection with a nearby mobile phone base station. If you hold a mobile phone in your left hand and your right hand, and use the left-hand mobile phone to dial the right-hand mobile phone, the electromagnetic waves of the mobile phone are not transmitted directly from the left hand to the right hand, but will be transmitted from the left-hand mobile phone to hundreds of meters away The mobile phone base station, and then make a big circle and transmit it back to the right mobile phone (except for the Bluetooth function). In normal times, the base station mobile phone is chatting hotly. The radio wave signals sent by both parties come and go, but when the full-band cell phone jammer is turned on, it will "beat gongs and drums" around the mobile phone, and the power of the received base station signal is much higher than that of the mobile phone. Times the "noise" radio wave signal, the mobile phone can't hear what the base station is talking about, and can't receive the signal from the base station normally, the connection between the two is cut off, and the mobile phone will become an island. are paralyzed.
The entire frequency band of electromagnetic waves ranges from a minimum of a few Hz to a maximum of tens of hundreds of GHz. The range is very large. Each section may be used as a communication signal. However, except for a small number of very professional equipment, ordinary full-band interference Instruments are "not loud enough" and "not complete in five tones". A full-band jammer can only interfere with a small part of the frequency band, and communication tools can use the uninterrupted frequency band for communication. Of course, all the 2G, 3G, 4G, and 5G mobile phone services of several domestic communication companies are concentrated in several small frequency bands, and the full-band jammers in the examination room can still concentrate on these frequency bands. When the full-band jammer is working, it will "sweep" electromagnetic waves from low frequency to high frequency in various frequency bands to interfere with the connection between the mobile phone and the base station.
In fact, there is basically no hope that the full-band jammer will make the mobile phone cheat, but cheaters can also use their own communication tools. to transmit the exam answers by radio. However, the road is one foot high and the devil is one foot high. Nanjing Bokang Electromechanical Technology Co., Ltd. can realize customization, achieve seamless shielding for 20--6000MHz, and ensure the fairness and fairness of the examination room.
DJI's DJI Mavic 3 (Royal 3) drones have been on the market for some time. Recently, a customer reported a problem when communicating with us: the drone jammers purchased and installed in the past are not suitable for this new type of drone. Xinjiang's DJI Mavic 3 (御3) UAV, it seems that the interference effect is not obvious, especially in terms of driving away and forced landing. If it is compared with the performance of other UAV models after being interfered, it feels that there will be A certain gap. The client wants to know why this is and what is a good solution?
First of all, we should know that every time DJI launches a new type of drone, its anti-jamming capability has been further optimized and upgraded. According to our detailed analysis and understanding, the DJI Mavic 3 (Royal 3) new drone of DJI, its remote control flight control and image transmission, the working frequency used is still the most commonly used 2.4G and 5.8G frequency bands, but in The frequency hopping anti-interference ability has been better strengthened. Compared with the previous models, the more special change is that the Beidou positioning module has been added to its navigation and positioning module. After understanding these, the reasons for the weakened function of UAV jammers in terms of driving away and forced landing can be roughly analyzed.