The US military is working on the next-generation of gps jammer to defeat improvised explosive devices (IEDs) that pose such a grave threat to US forces deployed overseas. The jammers are called Joint Counter Radio-Controlled Improvised Explosive Device (RCIED) Electronic Warfare (JCREW) devices. They are high-power, modular, programmable, multiband radio frequency jammers designed to deny enemy use of selected portions of the radio frequency spectrum. They come in 3 varieties – fixed, mounted, and dismounted.

The broader Marine Air Defense Integrated System is meant to shoot down drone jammer , fixed-wing aircraft, and helicopters and includes both non-kinetic (jamming) and kinetic weapons to down drones. The kinetic weapon is a 7.62-millimeter minigun mounted on the new Humvee replacement, the Joint Light Tactical Vehicle. The Marine Corps plans to eventually add laser weapons to LMADIS.

portable jammer cell phone signals during class will undoubtedly bring good effect to teachers, students and classroom order. However, the school should make public the screening period, so that teachers and students can give a warning to friends and relatives in advance, so as to avoid other adverse consequences due to lack of contact in the event of emergency. Schools may also consider other ways of providing emergency access to teachers and students during the screening period for emergencies.

GPS jamming technology can also be used to manage drones. Professor Todd Humphreys and his team have taken control of an unmanned drone through a GPS spoofing technique at Austin. They used tiny helicopters to disrupt the GPS systems on unmanned aircraft, and then to provide coordinates for drones to move towards their given targets. It's not the first time a drone's vulnerability has been exposed, it's easy to buy a wifi jammer on the Internet, and then force a drone to crash or other operations. And this signal interference is effective for all unmanned aircraft.

http://www.musublog.jp/blog/perfectjammer/

https://truxgo.net/blogs/35819/35309/the-use-of-jammers-is-controversial