U.S. navy research on jamming weapons

Comtech Telecommunications Corp.'s subsidiary -- to provide solid-state, high-power RF amplifier systems for use on the U.S. Navy’s Next Generation 4G jammer – Low Band (NGJ-LB) Demonstration of Existing Technologies (DET).

The NGJ system will augment, and ultimately replace the EA-18G Growler aircraft’s legacy ALQ-99 Tactical Jammer System with advanced airborne electronic attack capabilities for defeating increasingly advanced and capable threats.

The U.S. Navy’s EW Simulator Development RDT&E program develops technology and testing to ensure that jamming and self-protection systems provide advanced protection in the years ahead from both current and future threats. Of special interest to military planners is applying this work to such platforms as the all-important EA-18G Growler and F-35 Joint Strike Fighter.

Current and emerging EW programs that benefit from the EW Simulator Development effort include the ALR-67 radar warning receiver, the ALQ-214 Integrated Defensive Electronic Countermeasures suite, and the Next Generation Jammer, among many others.

The use of the jamming weapon

But what happens when the UAV is jammed? Commercial jammers and counter-UAV systems function by emitting strong signals towards the aircraft using the most commonly used frequencies for UAVs, which for communications are 900 MHz and 2.4 and 5.8 GHz, and for GPS are the L1 and L2 bands. The effect of the strong signals emitted by jammers is that the SNR (signal-to-noise ratio) is so small that the receiver cannot decode the real signal from the noise–similar to when we cannot understand someone speaking in a room full of other people talking.

When a UAV is portable jammer, the UAV will lose both GPS, and therefore navigation, and remote control from the pilot. Again, the most conservative option for the pilot is to maintain a constant attitude (pitch and roll equal to 0) and to descend in controlled way until the UAV touches the ground. This is what 99% of commercially available drones do and what makes jammers and other counter-UAV measures so effective.

The Republic of Singapore Air Force has several weapons at its disposal, including a jammer gun, which emits signals that can jam the control signals of drones, as well as a drone catcher system, which uses a net to catch them.