The principle of cell phone signal jammer from YIFALIU's blog
The shielding distance of the device has a great relationship with the power of the device and the use environment. There are several aspects that are helpful to the shielding effect: first, the output power of the device, second, the working mode of the shield, and third, the use environment (indoor or outdoor), The fourth is to shield the interference intensity of the surrounding environment.
Nowadays, mobile phones all use digital signals, and digital signals have strong anti-interference capabilities. Generally, the effect of using analog signal technology to interfere with digital signals is poor, so digital signals must be used to interfere with digital signals. Digital interference signals and analog interference signals of the same power have a negative impact on mobile phones. The interference effects are quite different. Jammers using digital jamming signal technology have lower power and higher efficiency than signal jammers using analog signal jamming technology.
The analysis of synthesis, attenuation, and reflection of indoor mobile phone signals and interference signals is very complex. Before shielding, the strength and quality of local mobile phone signals have a great impact on shielding. Different mobile phones have different effects. Generally, mobile phones with strong ability to receive weak signals may not necessarily have good anti-interference effects.
The direction of the base station and the direction of the mobile phone shielding area also affects the shielding effect. Generally, the signal strength in space is about -60 to -70dbm, and it can reach about -40dbm within a few hundred meters of the base station. The mobile phone reception strength range is generally between -35 to -95dbm. The higher the signal power strength of space mobile phones, the shorter the shielding distance.
The above is a conclusion based on the rules of radio signal transmission in free space. In reality, there are many obstacles on the ground that affect radio wave transmission. The above can only be used as a qualitative reference. Especially indoors, the above rules are very different from the actual situation. Therefore, this problem is difficult to calculate accurately at the moment and can only be determined based on the actual situation on site. Accurate construction projects must conduct preliminary research and signal testing, and then design specific solutions. In the later stage, timely tracking and testing are required, and certain corresponding supplements must be made to be foolproof, that is, to achieve a strict shielding effect.
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