Tutorial on How Mobile Phone Jammer Works

The GSM mobile jammer is a device which transmits the signals to the same frequency. The jamming section is successful when the area of the mobile phone signal is disabled if the jammer is on. The first jamming device was developed and used by the military for communication purpose. Where the planed commanders use RF communication to control their power and also in enemy communications. Nowadays the mobile users are increasing day by day, hence the mobile phone jammer devices are becoming civilian by comparing with the electronic devices to disable the mobile signals in specific locations.

What is a Mobile Jammer?

A mobile jammer is an instrument used to protect the cell phones from the receiving signal. The mobile jammer device broadcasts the signal of the same frequency to the GSM modem. The jamming is said to be successful when the mobile phone signals are disabled in a location if the mobile jammer is enabled.
Mobile Jammer
Mobile Jammer

Block Diagram of Mobile Jammer

The block diagram of the mobile jammer mainly includes power supply, IF section and RF section with an antenna.
Block Diagram of Mobile Jammer
Block Diagram of Mobile Jammer

Power supply

The power supply is used to provide the power to the entire sections in the mobile jammer with the available voltages. The basic block diagram of the power supply consists of the following parts.
Power Supply
Power Supply

Transformer: The transformer is used to transform the 220V AC to the other voltage levels(step up and step down)

Rectification: The rectification is used to convert the AC voltage to the DC voltage and this process can be done in two methods which are full wave & half wave rectification

Half wave Rectification: During the half wave rectification the input signal should be positive cycle, hence the output voltage will be appearing

Full wave Rectification: In this type of rectifications the input signal should be in both i.e. in positive and negative cycles hence the output voltage will be appear.

Filter: In this the large capacitors are used to minimize the ripples in the output. The filter is used in the output of full wave rectifier to eliminate the noise & fluctuations to provide the constant DC voltage

Regulators: The regulators are used to provide a preferred DC voltage

IF Section

The IF section is just a triangular or saw tooth wave generator. With the help of desired range of frequencies the tuning section of the jammer brushes the VCO. To compensate the proper amount of VCO from the desired frequency to the maximum. The noise which is mixed with triangular waves is generated by the tuning signal. The IF section is divided into three main sections which are given below
  • Noise generator
  • Mixer
  • Triangular wave generator

RF Section

The RF section is the heart of the mobile jammer because the output of the RF section is interacting with the mobile. There are three main sections in the RF section which are voltage controlled oscillator, power amplifier and antenna. The voltage controlled oscillator is very important in the RF section and it is a device. The RF section generates the RF signal which is interacting with the cell phones. The VCO output frequency is directly proportion to the input voltage, hence we can manage the output frequency with the help of input voltage. If the input voltage is DC then the out has a specific range of frequency or we have the triangular wave form is the input then the output will be extended to the specific range of frequency.

Mobile Jammer Circuit Diagram

The above circuit shows the mobile jammer circuit diagram and it is simple & easy to analyze. Basically the mobile jammer circuit consists of three main circuits. If the three main circuits are gathered then the output of that circuit is called as a jammer. The three circuits are mentioned below
Mobile Jammer Circuit Diagram
Mobile Jammer Circuit Diagram
  • RF amplifier
  • Tuning circuit
  • Voltage controlled oscillator
As we can see that the transistor Q1, and the two capacitors C4 & C5 and also with one resistor can compose the RF amplifier. By using the tuned circuit the RF amplifier amplifies the signal and the amplification signal is given to the antenna with the help of the capacitor C6 this capacitor will remove the DC signal and permit the AC signal. If the transistor Q1 is in ON state, then the tuned circuit at the collector end will be tune ON and the tuned circuit consists of capacitor C1 & inductor L1 hence it act as an oscillator with zero resistance. This oscillator will produce the high frequency with minimum impair. Both the indicator & capacitor in the tuned circuit will oscillate the resonating frequency.
The operation of the tuned circuit is easy to learn & understandable. If the tuned circuit is ON then the voltage is stored by the capacitor according to the capacity and the electric energy is the main function of the capacitor. Once the capacitor is fully charged it will allow the charge to flow through an indicator. Basically the inductor is used to store the magnetic energy through this voltage across the capacitor it will get decreased automatically, at the same time total magnetic energy is stored in the inductor and the charge of the capacitor will be zero. The inductor of the magnitude will be decreased and the capacitor will be charged with the help of current in a reverse polarity manner. After some period of time capacitor is charged completely and the magnetic energy transversely the inductor will be zero. Once again the capacitor will produce the charge to the inductor and becomes zero. After some time interval the capacitor will be charged with the help of an inductor and the capacitor will become zero.

The internal resistance is generated hence the oscillation will be stopped. The supply of the RF amplifier is through the capacitor C5 to the collector terminal which is before C6 for gain signal to the tuned signal. For generating noise the capacitors C2 and C3 are used for the frequency generated by the tuned circuit and these capacitors will produce the electronic pulses in random.

The cell phone Jammer works with the frequency of 450MHz if this frequency is hunk we need to generate the 450MHz frequency with same noise which is acted as a blocking signal because the receiver of the cell phone signal will not be able to understand the received signal. By this circuit we can able to block the cell phone signals.

Working of Mobile Jammer

The Mobile phone jammer devices transmit the similar radio frequency which is greater power than the cell phone. The communication between the cell phone and the base station of the phone tower is called as a denial of service attack.
Working of Mobile Jammer
Working of Mobile Jammer


This causes the obstruction with the communication of cell phones and towers to make the cell phones not viable and there is no network visibility. Hence it works in both ways i.e. Cell phone to the tower frequency and the other one is tower to mobile frequency.

Different Types of Mobile Jammers

There are different types of mobile jammers which are given below
  • Remote Controlled Mobile jammer
  • Adjustable Mobile Jammer
  • School & Prison Mobile Jammer
  • Explosion Proof Mobile jammer
  • Police & Military Mobile Jammer
  • Portable Mobile Jammer

Applications of Mobile Jammer

  • The Mobile jammers are used in the classrooms, and library to maintain silence
  • It is used in the seminar halls and meeting rooms to avoid disturbances
  • It is used in the hospitals
  • The mobile jammers are used in the temples, churches, etc.
This article is about the tutorial on how mobile jammer works and applications. I hope the given information in the article is helpful to give some good information and understanding the concept. For furthermore, if you have any queries regarding this concept or to implement electrical and electronic projects you can comment in the below section. Here is a question for you, Why we can’t use the mobile jammer on airplanes?
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Hi, I`m Sostenes, Electrical Technician and PLC`S Programmer.
Everyday I`m exploring the world of Electrical to find better solution for Automation. I believe everyday can become a Electrician with the right learning materials.
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