Modulator and modulation method for a wireless data transmission device

• US 8,274,370 B2
• Filed: 01/12/2007
• Issued: 09/25/2012
• Est. Priority Date: 07/12/2004
• Status: Active Grant

• Current Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Original Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Inventors: Friedrich, Ulrich, Fischer, Martin, Pangels, Michael
• Primary Examiner(s): BROWN, VERNAL U
• Application Number:
  US11/652,563
• Publication Number:
  US 20070109102A1
• Time in Patent Office: 2,083 Days
• Field of Search: 340/10.1, 340/825.2, 340/10.2, 340/10.4, 340/10.5, 340/10.3, 340/505
• US Class Current: 340/10.4
• 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

Abstract

In certain embodiments, an apparatus includes a rectifier and a switch. The rectifier is configured to modulate a received carrier signal. The switch is coupled to at least one node of the rectifier. The switch is configured to modify an impedance of the rectifier to modulate the received carrier signal by providing a potential to the at least one node of the rectifier based on a field strength of the received carrier signal and a modulation-control signal.

Claims

1. An apparatus comprising:

a rectifier configured to modulate a received carrier signal; and

a switch coupled to at least one node of the rectifier, the switch being configured to modify an impedance of the rectifier to modulate the received carrier signal by providing a potential to the at least one node of the rectifier based on a field strength of the received carrier signal and

a modulation-control signal.

2. The apparatus of claim 1, wherein the potential provided to the at least one node of the rectifier is a reference potential.

3. The apparatus of claim 1, further comprising a voltage sensor configured to provide a voltage based on the field strength of the received carrier signal, the voltage sensor being coupled between the switch the rectifier.

4. The apparatus of claim 3, further comprising an evaluation unit configured to control the providing of the potential to the at least one node of the rectifier based on the modulation-control signal and the voltage based on the field strength of the received carrier signal.

5. The apparatus of claim 3, further comprising a comparator configured to provide a signal when the voltage based on the field strength of the received carrier signal is higher than a reference voltage.

6. The apparatus of claim 1, wherein the at least one node of the rectifier is a high frequency node such that providing the potential to the high-frequency node performs phase modulation of the received carrier signal.

7. The apparatus of claim 1, wherein the rectifier is further configured to return the modulated received carrier signal to a base station.

8. The of claim 1, wherein the switch is one of a transistor, a metal-oxide-semiconductor field-effect transistor (MOSFET), a varactor, or a metal-oxide-semiconductor (MOS) varactor.

16. The apparatus of claim 1, wherein the at least one node of the rectifier is a low-frequency node, such that providing the potential to the low-frequency node performs phase modulation of the received carrier signal.

9. An apparatus comprising:

means for receiving a carrier signal from a base station;

means for modulating the received carrier signal; and

means for modifying an impedance of a rectifier to modulate the received carrier signal by providing a potential to at least one node of the rectifier based on a field strength of the received carrier signal and a modulation-control signal.

10. The apparatus of claim 9, further comprising means for providing a voltage based on the field strength of the received carrier signal.

11. The apparatus of claim 10, further comprising means for controlling the providing of the potential to the at least one node of the rectifier based on the modulation-control signal and the voltage based on the field strength of the received carrier signal.

12. The apparatus of claim 10, further comprising means for providing a signal when the voltage based on the field strength of the received carrier signal is higher than a reference voltage.

13. The apparatus of claim 9, wherein the potential provided to the at least one node of the rectifier is a reference potential.

14. The apparatus of claim 9, wherein providing the potential to at least one node of the rectifier comprises providing the potential to a high-frequency node of the rectifier for performing phase modulation of the received carrier signal.

15. The apparatus of claim 9, wherein providing the potential to at least one node of the rectifier comprises performing amplitude modulation of the received carrier signal by providing the potential to a low-frequency node of the rectifier.

17. A method comprising:

receiving a carrier signal from a base station;

modulating the received carrier signal; and

modifying an impedance of a rectifier to modulate the received carrier signal by providing a potential to at least one node of the rectifier based on a field strength of the received carrier signal and a modulation-control signal.

18. The method of claim 17, wherein the potential provided to the at least one node of the rectifier is a reference potential.

19. The method of claim 17, further comprising providing a voltage based on the field strength of the received carrier signal.

20. The method of claim 19, further comprising controlling the providing of the potential to the at least one node of the rectifier based on the modulation-control signal and the voltage based on the field strength of the received carrier signal.

21. The method of claim 19, further comprising-providing a signal when the voltage based on the field strength of the received carrier signal is higher than a reference voltage.

22. The method of claim 17, wherein providing the potential to at least one node of the rectifier comprises providing the potential to a high-frequency node of the rectifier for performing phase modulation of the received carrier signal.

23. The method of claim 17, wherein providing the potential to at least one node of the rectifier comprises providing the potential to a low-frequency node of the rectifier for performing amplitude modulation of the received carrier signal.