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 help the shielding effect: one is the output power of the device, the second is the working method of the shielding, and the third is the use environment (indoor or outdoor), The fourth is to shield the interference intensity of the surrounding environment.
Nowadays, mobile phones are all digital signals, and digital signals have strong anti-interference ability. Generally, analog signal technology is used to interfere with digital signals. Therefore, digital signals must be used to interfere with digital signals. The interference effect is very different. The jammer using digital interference signal technology has lower power and higher efficiency than the signal jammer using analog signal interference technology.
The analysis of synthesis, attenuation and reflection of indoor mobile phone signals and interference signals is very complicated. Before shielding, the strength and quality of mobile phone signals in the local space have a great impact on shielding. Different mobile phones have different effects. Generally, mobile phones with strong ability to receive weak signals may not have good anti-interference effects.
The direction of the base station and the direction of the shielded area of the mobile phone also affect the shielding effect. The general spatial signal strength is about -60 to -70dbm, the base station can reach about -40dbm within a few hundred meters, and the mobile phone reception strength range is generally between -35 and -95dbm. The higher the power of the mobile phone signal in space, the shorter the shielding distance.
The above is a conclusion based on the law of radio signal transmission in free space. In reality, there are many obstacles on the ground that affect the transmission of radio waves. The above can only be used as a qualitative reference, especially indoors. The above law is very different from the actual situation. Therefore, this problem is very difficult-accurately calculated at one time and can only be determined according to the actual situation on site. Precise construction projects must carry out preliminary research and signal testing, and then design specific solutions. In the later stage, timely follow-up tests are required, and certain corresponding supplements can be made to be foolproof, that is, to achieve the effect of strict shielding.