Coupling frames for RFID devices

Patent metadata

Field	Value
Publication number	US-9812782-B2
Application number	US-201615197795-A
Country	US
Kind code	B2
Filing date	Jun 30, 2016
Priority date	Aug 8, 2011
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

A transponder chip module (TCM) comprises an RFID chip (CM, IC), optionally contact pads (CP), a module antenna (MA), and a coupling frame (CF), all on a common substrate or module tape (MT). The coupling frame (CF) may be in the form of a conductive layer having an outer edge (OE) and a slit (S) or non-conductive stripe (NCS) extending from the outer edge to an inner position thereof which may be a central opening (OP). The coupling frame (CF) may be arranged so that the slit (S) or non-conductive strips (NCS) overlaps at least a portion of the module antenna (MA). Methods and apparatus are disclosed.

First claim

What is claimed is:

1. An RFID device comprising:
a transponder chip module (TCM) comprising an RFID chip (IC) and a module antenna (MA); and
a coupling frame (CF) comprising a conductive surface and having an electrical discontinuity comprising a slit (S) or non-conductive stripe (NCS) extending through the surface from an outer edge thereof to an inner position thereof, wherein the coupling frame is disposed so that the slit (S) or non-conductive stripe (NCS) overlaps at least a portion of the module antenna (MA).

2. The RFID device of claim 1 , wherein the coupling frame (CF) is disposed in a card body (CB) of a smart card (SC).

3. The RFID device of claim 1 , wherein the coupling frame (CF) is disposed on a module tape (MT) of the transponder chip module (TCM).

4. The RFID device of claim 1 , wherein the slit (S) or non-conductive stripe (NCS) extends to an opening (OP) in the coupling frame (CF).

5. The RFID device of claim 1 , wherein the slit (S) or non-conductive stripe (NCS) extends to an interior position of the coupling frame (CF).

6. The RFID device of claim 1 , wherein the slit (S) or non-conductive stripe (NCS) overlaps at least some turns of the module antenna (MA).

7. The RFID device claim 1 , wherein:
the transponder chip module (TCM) includes a module tape (MT) supporting the RFID chip (IC) and module antenna (MA); and
the coupling frame (CF) is disposed on an opposite side of the module tape (MT) from the module antenna (MA, PA).

8. The RFID device claim 1 , wherein:
the transponder chip module (TCM) includes a module tape (MT) supporting the RFID chip (IC) and module antenna (MA); and
the coupling frame (CF) is formed from a conductive layer (CL) on the module tape (MT) which is one of the (i) conductive layer used to form contact pads (CP) on the face-up side of the module tape (MT) and (ii) the conductive layer used to form the module antenna on the face-down side of the module tape (MT).

9. The RFID device claim 1 , wherein:
the module antenna (MA) comprises an etched planar antenna (PA) having a number of tracks (traces) separated by spaces;
wherein:
a track width is less than 100 μm; and
a spacing between adjacent tracks is less than 75 μm.

10. A method of improving coupling between an RFID device comprising a transponder chip module (TCM) and an external reader, the transponder chip module (TCM) comprising an RFID chip (IC, CM) and a module antenna (MA), characterized by:
incorporating an open-loop conductive coupling frame (CF) in the transponder chip module (TCM), wherein the coupling frame (CF) has a slit (S) or non-conductive stripe (NCS) extending from an outer edge (OE) thereof to an interior position thereof and coupling frame (CF) is positioned so that the slit (S) or non-conductive stripe (NCS) overlaps at least a portion of the module antenna (MA, PA, LES).

11. The method of claim 10 , wherein:
the coupling frame (CF) has an opening (OP) at the interior position thereof, and the opening defines an inner edge (IE) of the coupling frame (CF); and
the slit (S) or non-conductive stripe (NCS) extends from the opening (OP) to the outer edge (OE) of the coupling frame (CF).

12. In conjunction with an RFID device comprising an antenna having a number of tracks or turns separated by spaces, a coupling frame (CF) comprising a conductive surface and having an electrical discontinuity comprising a slit (S) or non-conductive stripe (NCS) extending through the surface from an outer edge thereof to an inner position thereof, wherein the coupling frame is disposed so that the slit (S) overlaps at least a portion of the module antenna (MA).

Assignees

• Finn David
• Lotya Mustafa
• Molloy Darren
• Féinics Amatech Teoranta

Inventors

• Finn David
• Lotya Mustafa
• Molloy Darren

Classifications

• H01Q7/00 Primary

  Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop · CPC title

• H01Q1/38

  formed by a conductive layer on an insulating support {(patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface  H01Q15/142)} · CPC title

• H01Q1/2225

  used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal · CPC title

• G06K19/07794

  the record carrier comprising a booster or auxiliary antenna in addition to the antenna connected directly to the integrated circuit · CPC title

• G06K19/07747

  at least one of the integrated circuit chips being mounted as a module · CPC title