Electronic proximity identification and recognition system with isolated two-way coupling

• US 4,600,829 A
• Filed: 04/02/1984
• Issued: 07/15/1986
• Est. Priority Date: 04/02/1984
• Status: Expired due to Fees

• Current Assignee: Charles A. Walton
• Original Assignee: Charles A. Walton
• Inventors: Walton, Charles A.
• Primary Examiner(s): Trafton, David L.
• Application Number:
  US06/596,065
• Time in Patent Office: 834 Days
• Field of Search: 235/439, 235/492, 340/825.31, 340/825.34, 343/6.8 R, 343/6.8 LC, 455/41
• US Class Current: 235/439
• CPC Class Codes: G06K 19/067 Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G07C 9/28 the pass enabling tracking or indicating presence

Abstract

An electronic proximity identification and recognition system. The identification and recognition sections are physically separate from one another, but inductively coupled to one another by two-way coupling. The identification section and recognition section each have a sending and a receiving antenna. The antennas in each section are structured to have virtually zero mutual inductance.

Claims

1. An electronic proximity recognition and identification system comprising:

a recognition section including an oscillator for supplying an electrical signal to a power amplifier electrically coupled to said oscillator, a first reader antenna connected to said power amplifier for radiating electromagnetic power responsive to said power amplifier, a second reader antenna for receiving signals, the mutual inductance between said first and second reader antennas being approximately zero; and

an electronic identifier section having a first identifier antenna for receiving radiated power from said first reader antenna, means for generating an identifier carrier frequency, and a second identifier antenna for radiating signals of said identifier carrier frequency to said second reader antenna, the mutual inductance between said first and second identifier antennas being approximately zero.

2. The system of claim 1, wherein said first and second reader antennas are loop antennas.

3. The system of claim 1 wherein

said first and second identifier antennas are loop antennas.

4. The system of claim 2 wherein

said first and second identifier antennas are loop antennas.

5. The system of claim 1, wherein

the identifier section includes logic and memory means for modulating said identification carrier frequency signal, and second identifier antenna for radiating said identification carrier frequency signal which signal is responsive to a code within said memory means.

6. The system of claim 5 wherein

said first reader antenna inductively couples to said first identifier antenna, and the second identifier antenna inductively couples to said second reader antenna.

7. The system of claim 1, wherein

said oscillator of the recognition section, oscillates within the radio frequency range;

and

said means for generating said identification carrier frequency operates within the radio frequency range.

8. The system of claim 2, wherein

said first and second reader antennas are tuned with capacitances to predetermined radio frequencies.

9. The system of claim 8 wherein

said first and second identifier antennas are tuned with capacitance to predetermined frequencies.

10. The system of claim 5, wherein

the recognition section includes a data processing unit for processing codes of said received signals.

11. The system of claim 10 wherein

the recognition section further includes a radio frequency amplifier electrically coupled to said second reader antenna.

12. The system of claim 11 wherein

said radio frequency amplifier includes means for automatic frequency control for locking onto the identifier frequency.