System that is apparentely used to jam AWACS and even radio electronic devices of low orbiting satelites is now deployed in Latakia region of Syria.
https://en.wikipedia.org/wiki/Krasukha_EW_System
http://gadgtecs.com/2015/10/09/spy-planes-signal-jammers-high-tech-weapons-syria/
It was also used (or it's smaler equivalent) to jam the radars of USS Donald Cook in the Black Sea last year even according to Pentagon sources:
“The US destroyer USS Donald Cook, equipped with Tomahawk cruise missiles entered the neutral waters of the Black Sea on April 10, 2014. The purpose was a demonstration of force and intimidation in connection with the position of Russia in Ukraine and Crimea. The appearance of American warships in these waters is in contradiction of the Montreux Convention about the nature and duration of stay in the Black Sea by the military ships of countries not washed by this sea. In response, Russia sent an unarmed bomber Su- 24 to fly around the U.S. destroyer. However, experts say that this plane was equipped with the latest Russian electronic warfare complex. According to this version, Aegis spotted from afar the approaching aircraft, and sounded alarm. Everything went normally, and the American radars calculated the speed of the approaching target. But suddenly all the screens went blank. Aegis was not working any more, and the rockets could not get target information. Meanwhile, Su-24 flew over the deck of the destroyer, did battle turn and simulated a missile attack on the target. Then it turned and repeated the maneuver. And did so 12 times.”