A system for generating a magnetic field for excitation of a leadless
marker assembly. The system of at least one embodiment includes a source
generator that generates a plurality of alternating electrical signals
each having an independently adjustable phase. A plurality of excitation
coils are configured to simultaneously receive a respective one of the
alternating electrical signals at a selected phase to generate a magnetic
field. The phase of the alternating electrical signal for each excitation
coil is independently adjustable relative to the phase of the alternating
electrical signal for the other excitation coils so as to adjust the
magnetic field from the respective coil. The magnetic fields from the
excitation coils combine to form a spatially adjustable excitation field
for excitation of the remote leadless marker assembly.
