SELECTIVELY COUPLING TO FEED POINTS OF AN ANTENNA SYSTEM

• US 20090058649A1
• Filed: 08/31/2007
• Published: 03/05/2009
• Est. Priority Date: 08/31/2007
• Status: Active Grant

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: Tuttle, John R.
• Granted Patent: US 7,936,268 B2
• Time in Patent Office: Days
• US Class Current: 340/572.100
• 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

Abstract

Selectively coupling to feed points of an antenna system. At least some of the illustrative embodiments are systems comprising an antenna system, an antenna communication circuit, a first diode coupled between the antenna communication circuit and a first feed point of the antenna system, and a second diode coupled between the antenna communication circuit and a second feed point of the antenna system. The antenna communication circuit is configured to couple the antenna communication circuit to the first and second feed points by forward biasing the diodes.

Claims

1. A system comprising:

an antenna system;

an antenna communication circuit;

a first diode coupled between the antenna communication circuit and a first feed point of the antenna system; and

a second diode coupled between the antenna communication circuit and a second feed point of the antenna system;

wherein the antenna communication circuit is configured to couple the antenna communication circuit to the first and second feed points by forward biasing the diodes.

2. The system according to claim 1 wherein the antenna communication circuit is configured to forward bias the diodes by applying a direct current (DC) current source to an anode of a selected diode.

3. The system according to claim 1 wherein the antenna system further comprises:

a radiative patch that defines a perimeter; and

a ground element, the radiative patch parallel and proximate to the ground element;

wherein the first and second feed points are one or more selected from the group consisting of;

within the perimeter; and

disposed on the perimeter.

4. The system according to claim 1 wherein the antenna system further comprises:

a first antenna having the first feed point and having a first polarization; and

a second antenna having the second feed point and having a second polarization.

5. The system according to claim 1 wherein the antenna communication circuit is one or more selected from the group consisting of:

a radio frequency identification (RFID) reader; and

a RFID circuit within an RFID tag.

25. The system according to claim 1 further comprising:

wherein the antenna communication circuit is a radio frequency identification (RFID) reader; and

a RFID tag communicatively coupled to the RFID reader.

26. The system according to claim 25 wherein the RFID tag further comprises:

a tag antenna having a plurality of feed points;

a RFID circuit; and

a plurality of diodes, at least one of said diodes coupled between each of the plurality of feed points and the RFID circuit;

wherein the RFID circuit is configured to selectively apply an antenna signal to the tag antenna through at least one of the plurality of diodes.

27. The system according to claim 26 wherein when the RFID circuit selectively applies the antenna signal the RFID circuit is configured to apply a bias current to a selected one of the plurality of diodes.

28. The system according to claim 26 further comprising a power source coupled to the RFID circuit.

6-16. -16. (canceled)

17. A semiconductor device comprising:

a substrate;

a first diode engaging the substrate, the first diode coupled to a first feed point of an antenna system;

a second diode engaging the substrate, the second diode coupled to a second feed point of the antenna system; and

a radio frequency identification (RFID) circuit engaging the substrate, the RFID circuit comprising an antenna signal line coupled to the first and second diodes.

18. The semiconductor device according to claim 17 wherein the RFID circuit is configured to selectively forward bias at least one of the first or second diodes.

19. The semiconductor device according to claim 17 wherein the RFID circuit is configured to couple the antenna signal line to the antenna system by selectively applying a bias current to at least one of the first or second diodes.

20. A system comprising:

a patch antenna having an active element defining a front of the patch antenna;

a first diode mechanically coupled to the patch antenna and electrically coupled to a first feed point of the active element of the patch antenna; and

a second diode mechanically coupled to the patch antenna and electrically coupled to a second feed point of the active element of the patch antenna;

wherein the first and second diodes are mechanically coupled to a location other than the front.

21. The system according to claim 20 where the first and second diodes are mechanically coupled to at least one selected from the group consisting of:

a back of the patch antenna; and

a side of the patch antenna.

22. The system according to claim 20 wherein the first and second diode engage the same substrate.

23. The system according to claim 20 further comprising an antenna communication circuit mechanically coupled to the patch antenna and electrically coupled to the first and second diodes.

24. The system according to claim 23 wherein the antenna communication circuit is configured to couple an antenna feed signal to the patch antenna by forward biasing at least one of the first or second diode.

29. A method comprising:

selectively coupling an antenna communication circuit to feed points of an antenna system, the selectively coupling comprising at least one selected from the group consisting of;

applying a forward biasing current by the antenna communication circuit to a first diode coupled between the antenna communication circuit and a first feed point of the antenna system; and

applying a forward biasing current by the antenna communication circuit to a second diode coupled between the antenna communication circuit and a second feed point of the antenna system.

30. The method according to claim 29 wherein selectively coupling further comprises selectively coupling the antenna communication circuit to feed points of an patch antenna having the first and second feed points.

31. The method according to claim 29 wherein selectively coupling further comprises selectively coupling the antenna communication circuit to at least one selected from the group consisting of:

a first antenna having the first feed point; and

a second antenna having the second feed point.

32. The method according to claim 29 wherein selectively coupling further comprises selectively coupling the antenna communication circuit being a radio frequency identification (RFID) reader to the antenna communication circuit.

33. The method according to claim 29 wherein selectively coupling further comprises selectively coupling the antenna communication circuit being a radio frequency identification (RFID) circuit to the antenna communication circuit.