Explanation of Frequently Asked Questions about Mobile Phone Signal Jammers from YIFALIU's blog

The higher the power of the cell phone signal jammer, the better the effect. In fact, this is not the case. For example, if a space is about 400-500 square meters, you should choose a mobile phone signal jammer that can block about 600 square meters. It’s not that the higher the power, the better. After all, the power of a mobile phone signal jammer has a safe power range. Some customers expressed why most merchants' machines have poor shielding effects when the signal source is very close, while some merchants have very good effects. In fact, the poor signal shielding effect when the signal source is close actually proves that these The merchant is a legitimate merchant. Is to comply with safety is the power range. On the contrary, when the signal source is very close, the shielding effect is very good and the power is quite high. It is important to pay attention to these machines, because such machines have exceeded the safe power of normal use. Not only will it affect the uplink signal source, but there are also potential safety hazards, so customers who purchase it should pay attention. Therefore, the bigger the power of the mobile phone signal jammer, the better.

1. output power

The output power of the shielder

Antenna radiation performance (antenna gain, directivity, etc.)

2. How shielding works

Nowadays, mobile phones use digital signals, and digital signals have strong anti-shielding capabilities. Generally, the effect of shielding digital signals using analog signal technology is poor, so digital signals must be used to shield digital signals. Digital shielding signals and analog shielding signals of the same power have a negative impact on mobile phones. The shielding effect is very different. The signal jammer for sale using digital signal shielding technology has lower power and higher efficiency than the jammer using analog signal shielding technology.

3. Indoor and outdoor are different

The analysis of synthesis, attenuation, and reflection of indoor mobile phone signals and shielded signals is very complex.

4. 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 a good anti-shielding effect.

5. The direction and distance of the signal source and the direction of the mobile phone shielding area also affect the shielding effect.

6. Shielding distance and radio signal transmission distance characteristics. Now we will briefly discuss the shielding distance based on the attenuation of radio signal transmission in free space. According to the transmission theory formula, every time the radio wave transmission distance is doubled, the signal strength is attenuated by 6db (the signal power is reduced by 4 times). . Let's take a certain mobile phone signal jammer GSM 900MHZ as an example. If the mobile phone signal strength in a certain area that needs to be blocked is -50dbm, and the effective shielding distance of the jammer is 10 meters, the change in mobile phone signal strength will directly affect the shielding distance. , see the table below for details:

Note: dbm is the abbreviation of dbmw, which represents the power intensity unit of radio equipment or signals, that is, decibel milliwatts

Generally, the signal strength in space is around -60 to -70dbm, and the maximum within a few hundred meters of the base station can reach around -40dbm. The mobile phone reception strength range is generally between -35 to -95dbm.

The higher the signal power intensity of space mobile phones, the shorter the shielding distance.

The above discussion is based on the rules of radio signal transmission in free space (the so-called free space is similar to space). In reality, there are many obstacles on the ground that affect radio wave transmission. The above conclusion can only be used as a qualitative reference, especially The above rules are very different from reality indoors. Therefore, this issue 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.