It maybe not a weapon, but can be a shockwave assigned to a Countermeasure, you just would have to make it EMP Shockwave, that way while you're getting away from your own countermeasure the explosion keeps expanding near you, but not at enough speed to give you the EMP status, while the other firghter will get the EMP distortion, and somewhat that will help you........
Also setting a high value Blast will help to make the shooter be confused......the Shockwave would need be low-damage, enough to be able to destroy multiple missiles and bombs that come behind you.....
It's something more like an EMP Mine, but it would help, at least the attacker will be advised to take distance before shooting........