Abstract: A resonant via-type connection between layers of a multilayer support structure having, at predetermined RF frequencies, a very low, effectively short circuit impedance. The resonant vias utilize the inductance of a via post by forming it into a resonant circuit with a capacitance at the via's distal end coupled to another conductor. A plurality of resonant vias can be formed having respective plurality of resonant frequencies to form a wideband connection. The capacitances at the vias' distal ends coupling to another conductor can be formed to resonate with the total series inductance of the via post and of wire connections to an attached device.

Abstract: New core geometries to increase the sensing range of proximity transducers in general, and eddy current killed oscillator mode sensors, in particular. A theoretical analysis yields electromagnetic parameters that facilitate prediction of the sensing capability of any ferrite core geometry. The results of this analysis is applied to a multitude of Finite Element Analysis models to study changes in maximum sensing distance due to ferrite core geometry modifications. This yielded preferred embodiments for shielded and unshielded sensors.