LC marker construction useful as an electromagnetically interrogatable transponder means

US5285191A · kind A · utility

Inventor

• Max Reeb · Uhingen, DE

Key dates

• Filing date: May 7, 1992
• Grant date: Feb 8, 1994
• Expiry date: May 7, 2012

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T29/49155
• WIPO field: Control
• WIPO sector: Instruments

Abstract

A planar LC marker construction useful as an electromagnetically interrogatable transponder is comprised of at least two conductive paths forming planar clockwise and counterclockwise turning spiral patterns (if viewed from the same side) aligned face-to-face, and turn by turn, in opposition to each other, and spaced by an insulative layer. The layer may have various components, at least one of which may be an adhesive layer to co-perform a capacitive function at radio frequency. At least in part that layer may configure as a sheet. The construction features a superior in-system detectivity owing to a very low RF electromagnetic field deflection, and can be produced cheaply for one-time use.