Radar jamming device
The Gap generator is a radar jamming device that was used in Second World War but it made a reappearance in Third World War. It was created by Albert Einstein to give the Allied forces a tactical advantage in reconnaissance and information warfare, and it served both these purposes admirably during the conflict.
Second World War
The Gap generator was one of the many genius inventions provided by Einstein that helped the struggling European Allies overcome their Soviet opposition during the Second World War. Its ability to disrupt radar signals and provide "dark sectors" for the Allied military was a godsend on more than one occasion, allowing Allied bases to spring up undetected with little fear of surveillance.
After the war ended, the Gap generator saw limited use near Allied bases, mostly serving as a deterrent for any sneaky ideas post-war Russia might be leaning towards. It changed little during this time period, with most alterations coinsiding with small advancements in radar tech.
Third World War
With the outbreak of the Third World War, America scrambled for any advantage they could get over the Soviet invaders, including assistance from the European nations. With Einstein once again providing his brilliant mind for the western side of the iron curtain, many of his older creations, such as the Gap Generator, saw a modernized return in the new Allied military. The device had changed little since its inception in WWII: other than its ability to jam modern radar signals, it was virtually the same as it had always been. This was both a good and bad thing as the generator was just as potent as ever, but at the same time it still suffered from the same energy consumption needs of the previous conflict. It saw use in both the American and European theaters of the war.
Psychic Dominator Disaster
After Allied time travel rebooted the Third World War, the Gap generator once again saw itself on the battlefield. This time, it appeared with several new modifications that allowed it to "bend" the psychic radar around itself, making it just as effective against Yuri's unusual radar technology as it had always been against conventional radar. Unfortunately, the modifications were not perfect: the overwhelming psychokinetic power of a "Psychic Reveal" was enough to temporarily overwhelm the generator's processors, revealing anything it hid for a few seconds.
War of the Three Powers
Cherdenko's erasure of Professor Einstein meant that the Allies no longer had the gap generator to serve in the Allied arsenal of Third World War. However the latest version of the Mirage Tank had a secondary function named the gap generator to hide any friendly units within its radius from the enemy.
Tactics and Counters
Like the Second World War version this gap generator would generate a black shroud to hide a large part of the player's (and opponents') bases from enemy radar. Even the Spy Satellite would not be able to remove the shroud generated by the Gap Generator, though it would reveal the location of that person's base. However destroying enough power plants would cause the gap generator to cease functioning or get an air view and destroy it first.
The Gap generator operates in a similar function to the Brotherhood of Nod's Stealth Generator in Tiberian Sun and Disruption Tower in Tiberium Wars. Both structures had the ability to "cloak" its affiliated bases from enemy radar, although via different approaches (Nod's "stealth" and Allies' "shroud"). As the Allies and Nod were similar in terms of technology and tactics in their first appearances, this may not be a coincidence.