Mobile phone interference circuit sharing

Mobile phones have become an essential gadget in our daily lives. But it can be annoying when used in inappropriate places like hospitals, schools, theaters, etc. For this purpose, a cell phone jammer circuit is used to block the signal received by the phone so that it does not work properly. But in some countries, the use of jammers is prohibited and you will be punished if you do so, so make sure that the law allows you to build and use this circuit.

Working principle of mobile phone interference circuit:

Typically, cell phones operate at specific frequencies, depending on the network and technology they use. But typically most mobile phones operate in a band between 800Mhz and 950Mhz. The above circuit uses a similar operating frequency range, which will cancel out the signal from the base station to the cell phone. This in turn confuses the cell phone and stops it working.

The working of this circuit starts with feeding the random noise signal signal as input. The signal can be anything (square wave, sine or voice signal) which is fed to capacitor C2 to remove the DC component from it. The signal is then fed to the RF oscillator built around the high frequency NPN transistor Q1 2N2222. The resistors R1 and R2 are used to fix the bias voltage to the base of the transistor.

The tank circuit used in the above circuit is built using two inductors and a variable capacitor to adjust the output frequency obtained from this circuit. This circuit is capable of providing frequency outputs from 725Mhz to 2.8GHz. Changing the position of the trimmer will change the output frequency. The frequency output can be determined by the formula.

F = 1/ 2¶ √LC

Based on this equation, we need to fix the capacitor value to 11pf to get a frequency range of about 850Mhz. You can use this formula to fix the LC value required for your desired output frequency.

Capacitor C3 is used to produce a continuous output frequency oscillation. Capacitor C4 is used to remove the DC component from the final output RF signal. You can use an RF antenna with this circuit or you can use an old cell phone antenna with this circuit for signal transmission. The range of this circuit is about 20 feet radius and is capable of killing the cell phones in it.

Notice:

Please use this circuit with caution, as some countries prohibit the use of cell phone jammers and you may be penalized.

Use the formula given above to fix the LC value for the desired frequency.

You may need to operate the jammer on a frequency based on the operating frequency your cell phone is using in the kill zone