Evading RF (radar frequency) missiles is not unlike running from a bear. You don't have to outrun the threat itself but merely offer up a more tasty morsel instead—be that your podgy mate or, in the case of air combat, a juicy decoy with an enormous radar cross-section.
The AN/ALE-50, nicknamed "Little Buddy", is a towed decoy designed to counter incoming RF missiles. Carried in an under-wing pylon and deployed at the end of a long tow rope, the ALE-50 exploits an RF missile's basic targeting function—that is, locking on and tracking their targets by continually pinging them with radar—by presenting a target with a massive radar cross section compared to the plane pulling it. The RF missile interprets this larger cross section as a bigger plane (and presumably more valuable target) and locks onto the decoy instead.
First developed in 1988, the US Air Force, Navy, and Marines now all employ this countermeasure in their F-16, F/A-18E/F, and B-1B aircraft. It's seen action in Kosovo, Afghanistan, and Iraq and has successfully intercepted missiles in both training and actual combat. [Raytheon - Wiki - Defense Industry Daily]
Photo: Luke - F16.net