How to Make 4G Cell Phone Jammer ?

        4G Cell phone Jammers are installed in no disturbance zones such as schools or colleges. But how exactly does this instrument jam cell phones? These jamming instruments prevent mobiles from receiving signals from the base stations. 
     Though it may sound like a complicated process making your own 4G cell phone jammer is not really a rocket science. You should know however that in many countries, including the USA, they are illegal and subject to large federal fines and possible criminal prosecution. Who knows what you might interfere with.

1

Understand the working principles. This 4g cell phone jammer operates at GSM800 frequency since most mobile phones use it to operate. So the selected VCO is a sweeping oscillator, which is very effective but may be hard to construct for the beginners without nice RF-testing equipment.

• As a noise source you can use a 45MHz clock oscillator which is driving a Local Oscillator port located on a mini-circuit mixer. There is also an impedance matching network for the Local Oscillator signal to pass through it. It is used to equate impedances of the clock oscillator and the port of the mixer.
• RF input (which is this port of the mixer) connects to the first 800MHz cell phone antenna, and the RF output is sent to the mini-circuit amplifier. This amplifier increases the output power for 15-16dbm. The amplified signal is then sent to the second cell phone antenna.

2

Know how it works. All cell phones which use GSM800 have their transmitted and received frequencies always separated by 45MHz. So when the mobile phone tries to call, it is blocked by its own signal returning to it! Isn’t that cool? When the phone blabber annoys you – turn your jammer on and that wrongdoer will hear own voice in his or her cell phone.

• Oh, by the way, you can also use this mobile signal jammer to block any cell-based tracking systems which use your GPS to track and record your car’s moves. And it is quite possible to jam IEDs which detonated using cell phones.
• The mixer used is designed to work up to 600MHz but in this case it works pretty well.
• RF amplifier is doing its job perfectly yet draws additional power.

3

Use an old aluminium box as a frame for the jammer and old UHF connectors from Motorola cell phone as input/output.

4

Attach RF connectors to the circuit.

5

Use a nine volt battery and voltage regulator to supply all components. Place the battery inside and separated by the foamed plastic from the other components.

• Place the power on/off switch on the top.

6

Screw the input and output antennas (also from old Motorola mobile phone) onto UHF connectors.

7

Your 4g cell phone jammer is ready. Enjoy!