[Trachmyr]

Actually you can make "Anti-Missile ECM's"...

Make a new PD weapon that only works at range 1, has no "firing animation" and an "electronic scrambling" sound, make it smaller than normal PD BUT make it only good vs. Seekers and lower it's weapon modifier, but give it enough damage to kill any seeker. This will give you a missile jammer that can affect one missile per turn, lower accuraccy means that the ECM will miss (how often depends on bonus).

Problems: Only works vs. 1 missile per "Jammer", and targeting sensors improve your "jamming" chance.