A miniature resonating marker assembly that includes, in one embodiment, a
ferromagnetic core, a wire coil disposed around the core, and a capacitor
connected to the wire coil adjacent to the magnetic core. The core, coil,
and capacitor form a signal element that, when energized, generates a
magnetic field at a selected resonant frequency. The magnetic field has a
magnetic center point positioned along at least one axis of the signal
element. An inert encapsulation member encapsulates the signal element
therein and defines a geometric shape of the resonating marker assembly.
The geometric shape has a geometric center point substantially coincident
with the magnetic center point along at least a first axis of the signal
element. The shape and configuration of the assembly also provides for a
miniature signal element specifically tuned to resonate at a selected
frequency with a high quality factor.