The decoy has its own radar signature, its really small. It can mimic a larger object by receiving, amplifying, and then transmitting the signal the enemy radar

The decoy has its own radar signature, its really small. It can mimic a larger object by receiving, amplifying, and then transmitting the signal the enemy radar signal. Smaller objects can get closer to radar before they are detected so the decoy projects an image of a larger aircraft to hide within. The radar sees the plane and starts tracking it. The decoy can likely use some fancy signal processing to move the image of the object around and even project multiple objects. Add more decoys and you can overload the object tracking of the radar station. The radar might be in range to see the actual decoy at some point but ideally the radar is seeing a bunch of phantom planes and missiles at this point so the decoy just blends in with the swarm. Radar already does something similar to what you are suggesting, there are spread spectrum techniques that are much more jam/spoof-proof than just a constant ping or even a linear frequency sweep. You pseudo-randomly hop frequencies to avoid having someone broadcast a really strong signal at one frequency and to have someone be able to track your pattern of hopping. The pattern is generated similar to crypto, you start with a seed (the plaintext) and encrypt it with a key to get the pattern that you hop with.