Many users who use wifi jammer for mobile phones do not understand its working principle and often overstep the frequency range when using it, resulting in improper use.
The principle of operation of mobile communication is that within a certain frequency range, wireless devices (mobile phones, etc.) communicate with the base station by radio waves and complete the transmission of data and sound with a certain speed. transmission and some modulation method. The mobile phone communicates with the base station via the uplink frequency, then transmits the signal to the mobile services switching center to initiate the call. In the standby state, the mobile phone communicates with the base station through the broadcast control channel. Once there is a call request, it will be allocated to the mobile phone service channel on demand according to the specific conditions of the channel near the terminal, so that the mobile phone can jump to the service channel to perform the call and data transmission.
According to the above working principles, a mobile phone jammer is usually composed of a power supply, an electronic scanning control unit, a segmented radio frequency module unit, an amplification unit and a transmitting antenna unit. The sweep signal generated by the signal generator passes through the inverter, enters the oscillator and modulates the working frequency band of mobile communication, then is amplified by the power amplifier, and the voltage regulator controls the power . The amplified frequency sweep signal is transmitted through the air in the form of radio waves. Since the frequency sweep signal causes scrambled interference on the message signal received by the mobile phone (the ratio of noise and noise signal at the threshold of the device increases), the mobile phone cannot receive the ordinary data sent by the base station, so that the mobile phone can not establish a normal connection with the base station, resulting in the disconnection of the mobile phone Open the communication network of the base station. The mobile phone shows no signal and no service system in the search network, which has got the blocking effect.
The interference power of the wave jammer is fixed and the shielding radius of the free space is determined by the path attenuation and the signal level of the receiving base station. In order to achieve the interference of the mobile phone signal jammer on the mobile network, it is necessary to make sure that the signal field emitted by the jammer is stronger than the mobile signal field 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. , The further the interference location is from the base station, the weaker the field strength and the larger the effective interference area.