Roadside bombs and other improvised explosive devices (IEDs) continue to account for a high percentage of military fatalities in Iraq and Afghanistan. This year alone, 158 of the 283 battlefield casualties among coalition soldiers in Afghanistan have been attributed to IEDs. These grim statistics, along with loss of civilian life and property damage, are driving a shift in focus from mitigating the effects of an explosive device detonation, such as the use of armor plating, to also neutralizing the threat prior to detonation. As the technology utilized by militants becomes more advanced, the field of electronic warfare provides the means to neutralize the threat posed by radio-controlled improvised explosive device (RCIED) detonation.

An RF jammer works by the prevention or disruption of a broadcast RF signal. If the jamming device can transmit a more powerful signal on the same frequency as the detonating transmitter, the threat is neutralized for the duration of the transmission of the jamming signal.

By permanently transmitting at a sufficient power level, an RF jammer effectively neutralizes the threat of RCIED detonation within its effective radius. There are several jamming methods used, depending on the type of RCIED.
Active bomb jammers transmit continuously, whereas reactive bomb jammers scan a range of frequencies and utilize detection algorithms to identify suspect signals. When a threat is identified, a reactive jammer focuses its signal against the perceived threat, allowing more power to be focused on the target frequency than can be achieved with an active jammer. Thus, the reactive type more suited to countering threats where the detonating transmitter is operates at power levels greater than 1 watt.

Broadband jammers are highly effective RF jammers with a wide range of operating frequencies, typically 20MHz up to 6GHz; representing the full range of transmitter and receiver technology available to militants, from radio controlled toy cars and citizens’ band radios, up to high frequency satellite phones. Utilizing barrage jamming, where a range of frequencies are transmitted simultaneously, or sweep jamming, where the transmission cycles through a range of frequencies rapidly, broadband jammers are typically deployed to counter low power RCIED transmitters operating under one watt. This is due to the broadband jammer’s available transmission power being spread over multiple frequencies, lowering its RCIED suppression capabilities. Sweep jamming helps to keep transmitter power high as the unit cycles through the programmed frequency range, but there is the possibility of a detonating signal slipping through between sweeps.

High power reactive jammers are typically coupled with active jammers to provide the maximum coverage against high and low power RCIED signals as the power of most RCIED transmission signals is below that of the surrounding electromagnetic environment.