RF jammer Types | Types of RF signal jammer techniques

RF jammer is used for RF signal jamming. The types of RF signal jammer techniques, mobile jammer block diagram and RF jammer manufacturers are mentioned.

RF jamming is the concept used to disrupt the transmission of a particular radio or satellite station. As a result of RF signal jamming, the desired wireless signal can not be received or decoded properly at the wireless receiver station.

The concept of signal jamming came into existence from military establishment. The idea is during the war situations when one country do not want their radio transmissions to be intercepted by their enemy. The army use RF signal jammers which does wireless signal jamming near the border areas. Following points are considered for the design of RF jammer.

RF Jammer
Figure-1 : RF Signal Jammer in communication

• Frequency of the RF jammer should be equal to the receiving station frequency; which need to be disrupted.
• Modulation type of RF jammer should also be equal to the disrupting station.
• Power of the RF jammer should be higher than disrupting station.

Types of jamming techniques

There are various different approaches followed in RF jamming to prevent mobile phones from ringing in a specific region or area. It is mainly used in worship places and in national border areas during wars. Following table mentions these different type of device. They are categorized into Type-A, Type-B, Type-C, Type-D and Type-E. Following table mentions types of jamming techniques.

Jammer Technique Type Emergency Call Efficiency Regularity Approval Implementation
Type-A Blocked Low Not allowed Very simple
Type-B Allowed Medium Needed complex, requires third party cellular services
Type-C Allowed High Needed Complex, requires intelligent handset
Type-D Allowed Medium Needed Simple
Type-E Blocked High(No signal transmission) Allowed Simple

Based on the above jammer types, buyer can decide on which type of signal jammer requires to be purchased. Pls. refer few of the RF jammer manufacturers below.

Jamming to signal ratio equation

As mentioned above, function of RF signal jammer is to insert an interference signal into the radio communication frequency in such a way so that actual signal (i.e. wanted signal) is completely submerged by the RF interference.

The effect of jamming signal depends upon J/S ( Jamming to Signal ratio ), interleaving, modulation type, channel coding technique of the target system.

Jamming to Signal ratio can be expressed by the following equation.
J/S = (Pj * Gjr * Grj * Rtr2 * Lr * Br)/(Pt * Gtr * Grt * Rjr2 *Lj * Bj)

Pj= RF Jammer Power
Pt= Transmitter power
Gjr= Antenna Gain from Jammer to the receiver
Grj= Antenna Gain from Receiver to the Jammer
Gtr=Antenna Gain from Transmitter to the receiver
Grt= Antenna Gain from Receiver to Transmitter
Br= Communications receiver Bandwidth
Bj= Jamming Transmitter Bandwidth
Rtr= Range between communication transmitter and receiver
Rjr= Range between Jammer and communication Receiver
Lj= Jammer Signal Loss, this includes polarization loss
Lr= Communication signal Loss

Mobile Jammer Block Diagram

Mobile Jammer Block Diagram
Figure-2 : Block diagram of Mobile Jammer

As mentioned in the mobile jammer block diagram above, mobile jammer consists of three main parts viz. power supply, IF section and RF section. Power supply section usually provides needed DC voltages to IF section and RF section. IF section generates IF frequency by tuning VCO module as desired. VCO is tuned by reference oscillator signal. RF section converts IF frequency to the RF frequency by using RF upconverter. This RF upconverted frequency is amplified using RF power amplifier and tra smitted using suitable RF antenna.

RF Signal Jammer manufacturers

Popular RF signal jammer manufacturers are as follows.
•  SESP Group
•  Enterprise Control Systems Ltd, UK, { manufacturer of RF inhibitors or RF Jammers}
•  WolvesFleet Technology Co.,Ltd. {jammers for vehicle,stationary application, bomb jammers, cellular Jammers,RF jammers}
•  HSS Development,75 South Broadway,New York,USA. {RF jammer,cellular jammer,portable and stationary bomb jammer,prison jammer,tactical jammer etc. }

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