Reactively coupled elements in circuits on flexible substrates

• US 6,181,287 B1
• Filed: 03/03/1998
• Issued: 01/30/2001
• Est. Priority Date: 03/10/1997
• Status: Expired due to Term

• Current Assignee: Precision Dynamics Corporation (Brady Corporation)
• Original Assignee: Precision Dynamics Corporation (Brady Corporation)
• Inventors: Beigel, Michael L.
• Primary Examiner(s): Ho, Tan
• Application Number:
  US09/034,176
• Time in Patent Office: 1,064 Days
• Field of Search: 343/742, 343/795, 343/726, 343/873, 343/793, 343/744, 340/505, 340/572, 340/825.54, 342/44, 342/57
• US Class Current: 343/741
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: G06K 19/0775 arrangements for connecting the integrated circuit to the antenna
• CPC Class Codes: G08B 13/2414 using inductive tags
• CPC Class Codes: G08B 13/2417 having a radio frequency identification chip
• CPC Class Codes: G08B 13/2431 Tag circuit details
• CPC Class Codes: G08B 13/2437 Tag layered structure, processes for making layered tags
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 1/2241 used in or for vehicle tyres
• CPC Class Codes: H01Q 11/12 Resonant antennas
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

An RFID circuit for incorporation in an identification device which includes a polymeric substrate, the circuit being formed or integrally connected with said substrate whereby said substrate becomes a component of the RFID circuit. Ax embodiment of the circuit includes circuit components printed or attached to opposite sides of said substrate utilizing the resistance of said substrate in a reactive or inductive circuit.

Claims

1. In a radio frequency identification circuit, the combination of:

a flexible, load-bearing and load-transmitting structural substrate;

electrically isolated components of said circuit formed on opposite surfaces of said substrate in overlying relationship with each other whereby said substrate creates a capacitive relationship between said components; and

an antenna connected to said circuit by said components.

2. The device of claim 1 in which the circuit components are imprinted in conductive ink.

3. The device of claim 1 in which the circuit components are fabricated from metallic foils.

4. The device of claim 1 in which the circuit components are polymer conductors.

5. In a radio frequency circuit, the combination of:

a flexible, load-bearing and load-transmitting structural substrate;

electrically isolated components of said circuit formed on opposite surfaces of said substrate in overlying relationship with each other whereby said substrate creates an inductive relationship between said components; and

an antenna connected to said circuit by said components.

6. In a radio frequency circuit, the combination of:

substrate means including a plurality of polymeric laminae secured in overlying relationship with one another, said laminae including a top lamina, a bottom lamina, and an intermediate lamina disposed between said top and bottom laminae, said radio frequency circuit being formed on one or more of said laminae;

electrically isolated circuit components formed on the top and bottom surfaces of said intermediate lamina to utilize said intermediate lamina as a circuit component; and

an antenna on one of said laminae connected to said radio frequency circuit by said components.

7. The device of claim 6 wherein the circuit components provide a reactive circuit.

8. The circuit of claim 6 wherein the circuit components provide an inductive circuit.

9. The radio frequency circuit of claim 6 which includes a plurality of antennae formed on opposite sides of said intermediate lamina in overlying relationship with each other.

10. The radio frequency circuit of claim 9 in which said antennae are operatively connected to said radio frequency circuit by a capacitive circuit of said components.

11. The circuit of claim 9 in which said antennae are operatively connected to said radio frequency circuit by an inductive circuit of said components.

12. In a circuit for an RFID, the combination of:

a flexible, load-bearing and load-transmitting structural substrate for said circuit, said substrate acting as a structural component of said RFID;

electrically isolated circuit components formed on opposite surfaces of said substrate in overlying relationship with each other to incorporate said substrate as an operative component of said circuit; and

an antenna on said substrate connected to said circuit circuit by said components.

13. The circuit components of claim 12 which ate capacitive and wherein said substrate operates as the dielectric component of said circuit components.

14. The circuit components of claim 12 which are inductive and wherein said substrate operates as the dielectric component of said circuit components.