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

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.