Conventional signal jammers use white noise broadband transmission and rely on power to suppress interference to achieve signal interference. With the rapid deployment of 5G base stations by various communication operators in recent years, the excessive density of base stations will cause customers to feel signal interference. The effective distance of jamming is shortened. So some customers proposed to increase the transmission power of the interference signal, and then the question arose: what is the interference effect after the power of the signal jammer is doubled? Can the interference distance be doubled?
The results are often regrettable. For example: in a certain practical application site, if the average transmission power of each output frequency band of a signal jammer is 2W, use a mobile phone to test the effective interference distance, assuming that the result of the field test is that the radius of the effective interference area is 10 m. If we replace it with a signal jammer with an average output power of 4W for testing, we will find that: first of all, its effective interference radius is almost impossible to double, that is, in this field environment, it is impossible to reach a radius of 20 meters. But at the same time, we can also find that compared with the original distance of 10 meters, after the transmission power is doubled, the effective interference distance will increase, but it will not be obvious, and it may be increased to about 12 or 13 meters. Even sometimes it feels like there is no change, and it remains at a position of about 10 meters. Why?
The reason is that in the field of radio frequency communication, the unit we usually use to convert the "W" that represents the radio frequency output power into a level value becomes "dBm". Here I recommend an oral calculation formula for converting the transmit power value into a level value: every time the "W" of the power doubles, the level value will increase by 3dBm. Still use the previous example to illustrate: when the output power is 2W, the corresponding level value is 33dBm, when the power is doubled and 2W becomes 4W, the corresponding level value is 36dBm, when the power is doubled, When 4W becomes 8W, the corresponding level value is 39dBm.
If the signal jammer wants to achieve a completely stable jamming effect, it is usually required that the strength of the jamming signal emitted by it, that is, the level value, should be at least 5~8dBm higher than the strength of the base station signal. In the real environment, due to the large number of base stations, there are many differences in the location and direction of distribution, and considering the influence of other factors, in the test site of the signal jammer, when we go to detect the signal strength of the base station, it is actually not fixed or not. Instead, it is in a state of beating and changing all the time. The signal of the base station is strong and sometimes weak, and the difference in beating may even reach more than 5dBm. Because of this, even if the signal jammer increases the transmission power by one part, that is, the level value increases by 3dBm, but the increase range may still be within the range of the base station signal's change and jump, so in the end it will be It is difficult to see a significant increase in the distance of signal interference.
