Antenna shield design for optimized em wave propagation in resistivity logging tools

A downhole resistivity tool comprising:

• a resistivity tool body having a longitudinal axis;
• a resistivity antenna deployed on the tool body;
• and
• an antenna shield deployed on the tool body about the antenna, the shield comprising a sleeve having opposing first and second sleeve ends with two spaced apart fingers formed in the sleeve between the opposing sleeve ends, each finger extending from adjacent an opposite sleeve end, the fingers each including a finger end that is electrically connected to an adjacent finger end by a transverse arm, the fingers being substantially parallel with the longitudinal axis of the tool body.

An antenna assembly for a downhole resistivity tool having a resistivity tool body defined along a longitudinal axis, the antenna assembly comprising:

• a resistivity antenna deployed on the tool body;
• and
• a metallic antenna shield deployed on the tool body about the antenna, the shield comprising a sleeve having a sleeve wall with opposing first and second sleeve ends;
• first and second spaced apart support columns formed by the sleeve wall, the support columns substantially parallel with one another and extending fully from the first sleeve end to the second sleeve end;
• first and second spaced apart, longitudinal slot segments formed through the sleeve wall and between the support columns, each slot segment extending from a first slot end adjacent one sleeve end to a second slot end adjacent the opposing sleeve end;
• and a transverse slot segment interconnecting an end of the first slot segment and an end of the second slot segment so as to form a finger between the first and second slot segments.