Oscillator tuning system and oscillator tuning method

• US 8,035,483 B2
• Filed: 01/10/2007
• Issued: 10/11/2011
• Est. Priority Date: 08/25/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Song, Il-jong, Yoon, Chol-su, Min, Young-hoon
• Primary Examiner(s): Wu; Daniel
• Assistant Examiner(s): Mahase; Pameshanand
• Application Number:
  US11/651,576
• Publication Number:
  US 20080055091A1
• Time in Patent Office: 1,735 Days
• Field of Search: 340/10.1, 340/10.41
• US Class Current: 340/10.1
• 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 19/0724 the arrangement being a circuit for communicating at a plurality of frequencies, e.g. for managing time multiplexed communication over at least two antennas of different types
• CPC Class Codes: G06K 19/0726 the arrangement including a circuit for tuning the resonance frequency of an antenna on the record carrier
• CPC Class Codes: G06K 7/10237 the reader and the record carrier being capable of selectively switching between reader and record carrier appearance, e.g. in near field communication [NFC] devices where the NFC device may function as an RFID reader or as an RFID tag
• 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 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

Abstract

An oscillator tuning system and an oscillator tuning method are provided. The system includes a determination unit which determines whether a power which is used in an RFID tag having an RFID oscillator is greater than a reference value; and a frequency tuner which tunes a driving frequency of the RFID oscillator according to a result of the determination. The method includes determining whether a power which is used in an RFID tag having an RFID oscillator is greater than a reference value; and tuning a driving frequency of the RFID oscillator according to a result of the determination.

Claims

1. An oscillator tuning system comprising:

a determination unit which determines whether a power which is used in an RFID tag having an RFID oscillator is greater than a reference value; and

a frequency tuner which tunes a driving frequency of the RFID oscillator according to a result of the determination,

wherein the determination unit determines a driving condition of the RFID oscillator as a near field region or a far field region as the result of the determination.

3. The oscillator tuning system of claim 1, wherein the frequency tuner

tunes the driving frequency of the RFID oscillator as an M multiple of 640 KHz if the driving condition is determined as the near field region, and

tunes the driving frequency of the RFID oscillator as an N multiple of 640 KHz, N being greater than M, if the driving condition is determined as the far field region.

4. The oscillator tuning system of claim 1, wherein the determination unit comprises a limiter which limits an electrical change of a variable to be less than a reference value, and the limiter outputs a Low or a High as an output by considering the variable at an established point within the limiter.

5. The oscillator tuning system of claim 4, wherein the limiter comprises at least one of a resistor chain, a diode chain, and a transistor chain.

6. The oscillator tuning system of claim 4, wherein, if the Low is output from the limiter,

the determination unit determines the driving condition of the RFID oscillator as the near field region as the result of the determination, and

the frequency tuner tunes the driving frequency of the RFID oscillator as an M multiple of 640 KHz.

7. The oscillator tuning system of claim 4, wherein, if the High is output from the limiter,

the determination unit determines the driving condition of the RFID oscillator as the far field region as the result of the determination, and

the frequency tuner tunes the driving frequency of the RFID oscillator as an N multiple of 640 KHz.

8. The oscillator tuning system of claim 1, wherein the frequency tuner tunes the driving frequency of the RFID oscillator by tuning an oscillator current flowing into the RFID oscillator.

17. The oscillator tuning system of claim 1, wherein the determination unit and the frequency tuner are provided on the RFID tag.

2. An oscillator tuning system comprising:

a determination unit which measures a distance from an RFID tag having an RFID oscillator to an RFID reader associated with the RFID tag, and determines whether the measured distance is greater than a reference value; and

a frequency tuner which tunes a driving frequency of the RFID oscillator according to a result of the determination,

wherein the determination unit determines a driving condition of the RFID oscillator as a near field region or a far field region as the result of the determination.

9. An oscillator tuning method comprising:

determining whether a power which is used in an RFID tag having an RFID oscillator is greater than a reference value; and

tuning a driving frequency of the RFID oscillator according to a result of the determination,

wherein the determining of whether the power which is used in the RFID tag having the RFID oscillator is greater than the reference value comprises;

determining a driving condition of the RFID oscillator as a near field region or a far field region as the result of the determination.

11. The oscillator tuning method of claim 9, wherein the tuning of the driving frequency of the RFID oscillator according to the result of the determination comprises:

tuning the driving frequency of the RFID oscillator as an M multiple of 640 KHz if the driving condition is determined as the near field region, and

tuning the driving frequency of the RFID oscillator as an N multiple of 640 KHz, N is being greater than M, if the driving condition is determined as the far field region.

12. The oscillator tuning method of claim 9, wherein the determining of whether the power which is used in the RFID tag having the RFID oscillator is greater than the reference value comprises:

limiting an electrical change of a variable to be less than a reference value; and

outputting a Low or a High as an output by considering the variable at an established point.

13. The oscillator tuning method of claim 12, wherein the limiter comprises at least one of a resistor chain, a diode chain, and a transistor chain.

14. The oscillator tuning method of claim 12, wherein, if the Low is output,

the determining of whether the power which is used in the RFID tag having the RFID oscillator is greater than the reference value further comprises determining the driving condition of the RFID oscillator as the near field region as the result of the determination, and

the tuning of the driving frequency tunes the driving frequency of the RFID oscillator the as an M multiple of 640 KHz.

15. The oscillator tuning method of claim 12, wherein, if the High is output,

the determining of whether the power which is used in the RFID tag having the RFID oscillator is greater than the reference value further comprises determining the driving condition of the RFID oscillator as the far field region, as the result of the determination, and

the tuning of the driving frequency tunes the driving frequency of the RFID oscillator the as an N multiple of 640 KHz.

16. The oscillator tuning method of claim 9, wherein the tuning of the driving frequency tunes the driving frequency of the RFID oscillator by tuning an oscillator current flowing into the RFID oscillator.

10. An oscillator tuning method comprising:

measuring a distance from an RFID tag having an RFID oscillator to an RFID reader associated with the RFID tag;

determining whether the measured distance is greater than a reference value; and

tuning a driving frequency of the RFID oscillator according to a result of the determination,

wherein the determining of whether the measured distance is greater than the reference value comprises;

determining a driving condition of the RFID oscillator as a near field region or a far field region as the result of the determination.