To my understanding every conductor reemits a bit of electromagnetic waves induced in it by radiation.
If theres a way in an antenna one could create a wave of opposite phase to the incident one so that there's no net oscillating field, could it make it invisible to radar?
this can be done my matching the electromagnetic impedance of the material to that of free air. By using dissipative elements (ohmic resistance) in the material to match impedances, the radar waves will be absorbed and dissipated, generating almost no reflection and thereby making the object invisible to radar. This is the fundamental principle of stealth materials.
