Abstract: The RF tag system of the present invention minimizes the effect of the RF tag on the overall radar cross section (RCS) of the object with which it is associated, tailors the signal reflected from the tag to match the actual RCS of the object with which it is associated, utilizes an RF tag design that reduces degenerative RF coupling at the tag, and is designed to exploit the operational features of conventional pulse Doppler radars. In accordance with one embodiment of the present invention, a radio frequency tag system is provided including an interrogator and a tag. The tag is secured to an object. The interrogator is configured to generate a transmitted electromagnetic interrogation signal at a predetermined interrogation frequency. The tag comprises an antenna array including a plurality of receiver antennas and a plurality of transmitter antennas.

Abstract: A system for and method of electromagnetically detecting an embedded dielectric region within a target object are provided. The method includes the steps of: (i) selecting a target object including a plurality of discrete scattering mediums, wherein the plurality of discrete scattering mediums include the embedded dielectric region and an adjacent dielectric region, and wherein the plurality of discrete scattering mediums define at least one dielectric interface between the embedded dielectric region and the adjacent dielectric region; (ii) directing electromagnetic radiation at the target object, wherein the electromagnetic radiation is characterized by a diagnostic frequency that is varied incrementally over a diagnostic frequency band; (iii) detecting electromagnetic radiation reflected by the target object over the predetermined frequency band such that there are M measurements of a reflected electromagnetic signal at frequencies f.sub.1, f.sub.2, . . . , f.sub.