You must have missed the part where a 50k$ Czech passive radar is defeating the F35 stealth capability.
Problem of EM sensors is most often then not, are active (especially radars and IFF), they broadcast or ping signals thus leaving quite a huge EM signature that can be pinpointed precisely with 3 antennas.
Problem of EM sensors is most often then not, are active (especially radars and IFF), they broadcast or ping signals thus leaving quite a huge EM signature that can be pinpointed precisely with 3 antennas.