Patent ID: 8368403

Claim:
A downhole logging tool, comprising: a tool body having a longitudinal axis; a set of co-located antennas carried on the tool body, two or more of the co-located antennas having orthogonal magnetic moments, one or more of the co-located antennas being formed from a pair of diametrically opposed antenna sections, each antenna section comprising a coil having a non-rectangular, curvilinear winding pattern; one or more additional antennas carried on the tool body spaced longitudinally apart from the set of co-located antennas; a shield, electromagnetically transparent to at least two co-located antennas having orthogonal magnetic moments, the shield having, for each antenna section, a linear segment, axially aligned slot therethrough substantially centered over a longitudinal axis of the antenna section coil, one or more linear segment, axially aligned slots therethrough disposed over and beside the antenna section coil, and linear segment, non-axially aligned slots therethrough disposed over the non-rectangular, curvilinear winding pattern of the antenna section coil, wherein each of the linear segment, non-axially aligned slots is substantially perpendicular to the underlying non-rectangular, curvilinear winding pattern of the antenna section coil and one or more of the linear segment, non-axially aligned slots is sloped at some non-transverse angle, and wherein a first path length around a slot is more than twice a second path length between two adjacent slots along an arc of the non-rectangular, curvilinear winding pattern, the shield circumferentially surrounding the set of co-located antennas; and an electromagnetically transparent shield having axially and non-axially aligned slots therethrough, wherein each of the slots is substantially perpendicular to the most proximate windings of the underlying antenna, the shield circumferentially surrounding each of the one or more additional antennas.