Why can wireless signal jammer block mobile phone signals?
Many users who use wireless signal jammers do not understand its working principle, and their use often exceeds the frequency range, resulting in poor use results.
The working principle of the wifi signal jammer is that within a certain frequency range, wireless devices (mobile phones, etc.) and base stations communicate through radio waves to complete data and sound transmission at a certain baud rate and modulation method. When the mobile phone communicates, it communicates with the base station through the uplink frequency, and then transfers the signal to the mobile service exchange center to complete the call. In the standby state, the mobile phone communicates with the base station through the broadcast control channel. Once there is a call demand, the mobile phone will first be assigned a business channel according to the specific conditions of the channel near the terminal through request, so that the mobile phone jumps to the business channel to complete the call and data transmission. . At the same time, wireless communication must ensure a sufficient signal-to-noise ratio to effectively receive and complete communication.
Based on the above working principle, wireless signal jammers are generally composed of power supply, electronic scanning control unit, segmented radio frequency module unit, amplifier unit, transmitting antenna unit and other parts. After the signal generator generates a scanning signal and passes through the inverter, it enters the oscillator and is modulated to the mobile communication operating frequency band. It is then amplified by a power amplifier and controlled by a voltage regulator tube. The amplified frequency sweeping signal is launched into the air in the form of radio waves. Because the frequency sweep signal causes garbled interference in the message signal received by the mobile phone (increasing the proportion of noise signals to the device threshold), the mobile phone cannot receive normal data sent by the base station, so that the mobile phone cannot establish a normal connection with the base station, causing the mobile phone to disconnect. Base station communication network. The mobile phone shows symptoms such as no signal on the search network and no service system, achieving a blocking effect.
The interference power of the wireless signal jammer is certain, and the shielding radius of the unobstructed space is determined by the path attenuation and the received base station signal level. In order for a cell phone signal jammer to interfere with the mobile network, it must be ensured that the signal field emitted by the jammer is stronger than the field strength of the mobile signal in the interference area. The closer the interference location is to the base station, the stronger the field strength and the smaller the effective interference area, and vice versa. , the farther the interference location is from the base station, the weaker the field strength and the larger the effective interference area.
It can be seen that within a certain transmit power, the interference range depends on the field strength in the interference area. No matter how powerful the wireless signal jammer is, as long as the transmit power is a fixed value, as the interval increases, the interference signal strength will gradually attenuate. , thereby losing the ability to interfere.
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