Method and system for a RFID transponder with configurable feed point for RFID communications

• US 9,013,311 B2
• Filed: 06/09/2010
• Issued: 04/21/2015
• Est. Priority Date: 06/09/2009
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Rofougaran, Ahmadreza, Rofougaran, Maryam
• Primary Examiner(s): YANG, JAMES J
• Application Number:
  US12/797,041
• Publication Number:
  US 20100308970A1
• Time in Patent Office: 1,777 Days
• Field of Search: 340 101- 106, 3405721-5729, 235375-385
• US Class Current: 340/572.7
• CPC Class Codes: G01S 13/06 Systems determining position data of a target
• CPC Class Codes: G06K 7/10316 using at least one antenna particularly designed for interrogating the wireless record carriers antennas in general H01Q1/22
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/13091 Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01Q 1/2283 mounted in or on the surface of a semiconductor substrate as a chip-type antenna or integrated with other components into an IC package
• CPC Class Codes: H01Q 13/20 Non-resonant leaky-waveguide or transmission-line antennas; Equivalent structures causing radiation along the transmission path of a guided wave
• CPC Class Codes: H01Q 13/22 Longitudinal slot in boundary wall of waveguide or transmission line H01Q13/203 takes precedence
• CPC Class Codes: H01Q 15/006 Selective devices having photonic band gap materials or materials of which the material properties are frequency dependent, e.g. perforated substrates, high-impedance surfaces
• CPC Class Codes: H01Q 15/0066 said selective devices being reconfigurable, tunable or controllable, e.g. using switches
• CPC Class Codes: H01Q 15/23 Combinations of reflecting surfaces with refracting or diffracting devices
• CPC Class Codes: H01Q 19/06 using refracting or diffracting devices, e.g. lens radome H01Q1/42
• CPC Class Codes: H04B 1/0458 Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages matching circuits in general H03H
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 7/24 for communication between two or more posts wireless communication networks H04W

Abstract

A Method and system for a RFID transponder with configurable feed point for RFID communications is provided. In this regard, an RFID transponder may receive RF signals via a leaky wave antenna and modulate an amplitude of a backscattered signal associated with the received RF signals by switching between a plurality of feed points of the leaky wave antenna to vary an input impedance of said RFID transponder. Each of the plurality of feed points may be located in a different position in the resonant cavity of the leaky wave antenna. The input impedance may be controlled by switching a load in and out of a receive path of the RFID transponder. The leaky wave antenna may be integrated within and/or on an integrated circuit, an integrated circuit package, or a combination thereof.

Claims

1. A method for communication, the method comprising:

receiving RF signals via a leaky wave antenna of a radio frequency identification (RFID) transponder that includes an integrated circuit external to said leaky wave antenna; and

modulating an amplitude of a backscattered signal associated with said received RF signals by controlling an input impedance of said RFID transponder,

wherein said input impedance is controlled by switching between a plurality of feed points of said leaky wave antenna using a feed point switch in said integrated circuit, each feed point having a different position relative to a distance between a partially reflective surface and a reflective surface that define a cavity of the leaky wave antenna,

a positive terminal of each of at least two of said plurality of feed points is coupled to a different positive terminal of said integrated circuit and a negative terminal of each of said at least two of said plurality of feed points is coupled to a negative terminal of said integrated circuit, and

each said different positive terminal is controlled by said feed point switch.

2. The method according to claim 1, comprising varying said input impedance by switching a load in and out of a receive path of said RFID transponder.

3. The method according to claim 1, comprising switching between said plurality of feed points via a micro-electromechanical system switch.

4. The method according to claim 1, wherein each of said plurality of feed points is located in the cavity of said leaky wave antenna.

5. The method according to claim 1, wherein said leaky wave antenna is integrated within or on an integrated circuit, an integrated circuit package, or a combination thereof.

6. The method according to claim 1, comprising modulating a frequency of said backscattered signal by controlling the distance between the partially reflective surface and the reflective surface that form the cavity of said leaky wave antenna.

7. The method according to claim 6, comprising controlling said distance between the partially reflective surface and the reflective surface via a micro-electromechanical system.

8. The method according to claim 1, wherein said received RF signals cause charge to accumulate on one or more capacitors in said RFID transponder resulting in a voltage that at least one of controls and powers one or more portions of said RFID transponder.

9. The method according to claim 8, comprising controlling, with said voltage, a switch that connects and disconnects a battery of said RFID transponder to one or more other components of said RFID transponder.

10. The method according to claim 8, comprising powering, with said voltage, at least one of a radio subsystem and a processing subsystem of said RFID transponder.

11. A system for communication, the system comprising:

one or more circuits in a radio frequency identification (RFID) transponder comprising a leaky wave antenna and an integrated circuit external to said leaky wave antenna, said one or more circuits being configured to;

receive RF signals via the leaky wave antenna of the RFID transponder; and

modulate an amplitude of a backscattered signal associated with said received RF signals by controlling an input impedance of said RFID transponder,

where said input impedance is controlled by switching between a plurality of feed points of said leaky wave antenna using a feed point switch in said integrated circuit, each feed point having a different position relative to a distance between a partially reflective surface and a reflective surface that define a cavity of the leaky wave antenna,

a positive terminal of each of at least two of said plurality of feed points is coupled to a different positive terminal of said integrated circuit and a negative terminal of each of said at least two of said plurality of feed points is coupled to a negative terminal of said integrated circuit, and

each said different positive terminal is controlled by said feed point switch.

12. The system according to claim 11, wherein said one or more circuits are configured to vary said input impedance by switching a load in and out of a receive path of said RFID transponder.

13. The system according to claim 11, wherein said one or more circuits comprise a micro-electromechanical system switch to switch between said plurality of feed points.

14. The system according to claim 11, wherein each of said plurality of feed points is located in the cavity of said leaky wave antenna.

15. The method according to claim 11, wherein said leaky wave antenna is integrated within or on an integrated circuit, an integrated circuit package, or a combination thereof.

16. The system according to claim 11, wherein said one or more circuits are configured to modulate a frequency of said backscattered signal by controlling the distance between the partially reflective surface and the reflective surface that form the cavity of said leaky wave antenna.

17. The system according to claim 16, comprising a micro-electromechanical system configured to control said distance between the partially reflective surface and the reflective surface.

18. The system according to claim 11, wherein:

said one or more circuits comprise one or more capacitors and diodes;

said received RF signals cause charge to accumulate on said one or more capacitors resulting in a voltage that at least one of controls and powers at least a portion of said one or more circuits.

19. The system according to claim 18, wherein:

said one or more circuits comprise a switch that connects and disconnects a battery of said RFID transponder to one or more other components of said RFID transponder; and

said switch is controlled with said voltage.

20. The system according to claim 18, wherein said one or more circuits comprise a radio subsystem and a baseband processing subsystem and said voltage powers at least one of said radio subsystem and said processing subsystem.