Communication devices, a radio frequency identification device, and methods of communicating

• US 6,717,923 B1
• Filed: 11/24/1999
• Issued: 04/06/2004
• Est. Priority Date: 02/04/1998
• Status: Expired due to Fees

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: Smith, Freddie W.
• Primary Examiner(s): Holloway, III, Edwin C.
• Application Number:
  US09/449,031
• Time in Patent Office: 1,595 Days
• Field of Search: 370/278, 455/101, 455/106, 455/107, 455/78, 455/272, 455/277.1, 455/279.1, 455/282, 455/80, 455/81, 455/129, 342/42-51, 340/10.1, 340/10.34, 340/572.1, 340/572.7, 340/933, 340/572.5, 343/755, 343/815, 343/834, 343/844, 343/701, 343/700.MS, 343/777
• US Class Current: 370/278
• 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 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 19/07767 the first and second communication means being two different antennas types, e.g. dipole and coil type, or two antennas of the same kind but operating at different frequencies
• CPC Class Codes: G06K 19/07779 the inductive antenna being a coil
• CPC Class Codes: G06K 19/07786 the antenna being of the HF type, such as a dipole
• 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: 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 1/241 used in mobile communications, e.g. GSM H01Q1/247, H01Q1/248 take precedence
• CPC Class Codes: H01Q 1/38 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 Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching
• CPC Class Codes: H01Q 3/247 by switching different parts of a primary active element
• CPC Class Codes: H01Q 7/00 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 Class Codes: H01Q 9/16 with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole H01Q9/44 takes precedence

Abstract

The present invention provides communication devices, communication systems and methods of communicating. According to one embodiment of the invention, a communication device includes: a first antenna operable to receive wireless communication signals; a second antenna having plural leads, the second antenna being operable to output wireless communication signals; a connection including plural conductive lines having respective first ends and second ends, the connection being coupled with the leads of the second antenna at the first ends of the lines; and a switch coupled with the second ends of the connection, the switch being operable to provide one of selective shorting and isolation of the leads. One method of communicating of the invention includes: forming a first antenna; forming a second antenna; receiving wireless interrogation signals using the first antenna; outputting wireless identification signals using the second antenna; opening a coupling intermediate plural leads of the second antenna during the receiving.

Claims

1. A communication device comprising:

a first antenna operable to receive wireless communication signals;

a second antenna having plural leads, the second antenna being operable to output wireless communication signals;

a connection including plural conductive lines having respective first ends and second ends, the connection being coupled with the leads of the second antenna at the first ends of the lines;

a switch coupled with the second ends of the lines, the switch being operable to provide selective shorting and isolation of the leads to alter an impedance of the second antenna between a low impedance and a high impedance greater than the low impedance; and

wherein the connection provides the low load impedance of the second antenna during receiving of wireless communication signals via the first antenna.

2. The communication device according to claim 1 wherein the first antenna and the second antenna are separated by a distance approximately equal to the wavelength of the wireless communication signals.

3. The communication device according to claim 1 wherein the connection comprises a transmission line.

4. The communication device according to claim 1 wherein the connection has a length approximately equal to one quarter the wavelength of the wireless communication signals.

5. The communication device according to claim 1 wherein the switch is open during receiving of wireless communication signals via the first antenna.

6. The communication device according to claim 1 wherein the communication device comprises a radio frequency identification device.

7. The communication device according to claim 1 wherein the first antenna and second antenna are configured to beam form during receiving of wireless communication signals.

8. The communication device according to claim 1 further comprising a microprocessor coupled with the switch, the microprocessor being operable to control the switch.

9. The communication device according to claim 1 further comprising an integrated circuit comprising a microprocessor and a transponder coupled with the first antenna and second antenna.

10. The communication device according to claim 1 wherein the communication device comprises a wireless identification device.

11. The communication device according to claim 1 wherein the switch is operable to provide the selective shorting and isolation of the leads to implement backscatter communications.

12. The communication device according to claim 11 wherein the backscatter communications are implemented to provide identification operations of a radio frequency identification device.

24. The communication device according to claim 12 wherein the backscatter communications are implemented to provide identification operations of a radio frequency identification device.

13. A communication device comprising:

a first antenna operable to receive wireless communication signals;

a second antenna having plural leads operable to output wireless communication signals, the second antenna being selectively configured between a first load impedance and a second load impedance lower than the first load impedance;

a switch electrically coupled with the second antenna, the switch being selectively operable to close to electrically short the leads and open to electrically insulate the leads;

a transformer intermediate the switch and the second antenna, the transformer being configured to effect the second load impedance of the second antenna responsive to the switch being open; and

wherein the switch is controlled to be open during the receiving of wireless communication signals to provide the second load impedance of the second antenna during the receiving via the first antenna and using the transformer.

14. The communication device according to claim 13 wherein the communication device comprises a radio frequency identification device.

15. The communication device according to claim 13 wherein the transformer has a length approximately equal to one quarter the wavelength of the wireless communication signals.

16. The communication device according to claim 13 wherein the switch is selectively opened and closed during outputting of the wireless communication signals.

17. The communication device according to claim 13 further comprising an integrated circuit including a transponder configured to receive and output wireless communication signals.

18. The communication device according to claim 17 wherein the switch is implemented within the integrated circuit.

19. The communication device according to claim 17 wherein the integrated circuit further comprises a microprocessor operably coupled with the switch, the microprocessor being configured to control the switch.

20. The communication device according to claim 13 wherein the first antenna and second antenna are configured to beam form during receiving of wireless communication signals.

21. The communication device according to claim 13 wherein the first antenna and the second antenna are separated by a distance approximately equal to the wavelength of the wireless communication signals.

22. The communication device according to claim 13 wherein the communication device comprises a wireless identification device.

23. The communication device according to claim 13 wherein the switch is operable to provide the shorting and insulation of the leads to implement backscatter communications.

25. A method of communicating within a radio frequency identification device comprising:

forming a forward link antenna upon a first surface of a substrate;

forming a return link antenna upon the first surface of the substrate;

receiving wireless communication signals via the forward link antenna;

outputting wireless communication signals via the return link antenna responsive to the receiving;

spacing the forward link antenna and the return link antenna a distance of approximately one wavelength of the received and outputted wireless communication signals;

switching the impedance of the return link antenna during the outputting using a switch coupled with plural leads of the return link antenna;

opening the switch during the receiving;

transforming the load impedance of the return link antenna during the receiving using a transmission line having a length of approximately one quarter the wavelength of the received and outputted wireless communication signals; and

beam forming using the forward link antenna and the return link antenna.