in the same or substantially the same plane as the lc resonant frequency circuit or is in a close generally parallel plane to the circuit it will be appreciated by those of ordinary skill in the art that the amplification shield may be spaced from the lc resonant frequency circuit if desired and may be in a different plane fig7 for example if desired the lc resonant frequency circuit could overlap all or a portion of the amplification shield but if there is an overlap it is preferably only a slight overlap the lc resonant frequency circuit could be spaced from the amplification shield by preferably the spacing is small while not being limited to a particular theory both the lc resonant frequency circuit and the amplification shield are passive in that they are not required to be a source of energy but are responsive to energy in an electromagnetic field fig2 illustrates a first example of a preferred embodiment of a lc resonant frequency circuit 5 in the form of an exemplary lc resonant tag 10 and a surrounding amplification shield 12 while not being limited to a particular theory the amplification shield 12 is comprised of a planar layer of metal foil with a thickness of about 38 microns and is generally in the configuration of a square while the thickness of about 38 microns is a preferred.