RADIO FREQUENCY IDENTIFICATION (RFID) POSITIONING APPARATUS AND METHOD THEREOF

• US 20090058607A1
• Filed: 09/01/2008
• Published: 03/05/2009
• Est. Priority Date: 08/31/2007
• Status: Abandoned Application

• Current Assignee: G-Time Electronic Company Limited
• Original Assignee: G-Time Electronic Company Limited
• Inventors: WU, YING-FENG, WU, CHE-MING, HOU, TIEN-FA
• Application Number:
  US12/202,353
• Publication Number:
  US 20090058607A1
• Time in Patent Office: Days
• US Class Current: 340/10.100
• CPC Class Codes: G06K 7/10079 the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions
• CPC Class Codes: G06K 7/10336 the antenna being of the near field type, inductive coil
• CPC Class Codes: G06K 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 21/061 Two dimensional planar arrays
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching
• 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

This invention discloses a RFID positioning apparatus and a method for identifying and positioning at least one RFID tag. The apparatus comprises a transmission module for transmitting a frequency, a capacitor, sensing modules, an identification module and circuit modules. A first switching unit of the sensing module performs a connection operation according to the frequency to form a magnetic flux of a induction coil and the capacitor, such that the first induction coil senses an identification signal of a RFID tag. The identification module receives the identification signal for identifying and positioning the RFID tag. Each circuit module is connected to the transmission module, sensing module, capacitor and identification module, and transmits the identification signal. The circuit modules have substantially equal length to achieve a matched status of all induction coils.

Claims

1. A radio frequency identification (RFID) positioning apparatus, capable of identifying and positioning at least one RFID tag, and the RFID positioning apparatus comprising:

a transmission module capable of transmitting a frequency;

at least one capacitor;

a plurality of sensing modules, each having a first switching unit, at least one induction coil, and the first switching unit selectively performing a connection operation and a disconnection operation, wherein the connection operation makes a magnetic flux formed in the induction coil and the capacitor, such that the induction coil senses an identification signal of the RFID tag according to the magnetic flux;

an identification module capable of receiving the identification signal to identify and position the RFID tag; and

a plurality of circuit modules, each circuit module connected to the transmission module, one of the sensing modules, the capacitor and the identification module, for transmitting the identification signal;

wherein, the circuit modules have a length substantially equal to each other to enable all induction coils being a match status.

2. The apparatus of claim 1, wherein each sensing module further includes a second switching unit, for avoiding two identification signals from transmitting to the identification module at the same time.

3. The apparatus of claim 1, wherein each sensing module further includes a grounding unit, for avoiding other induction coils from interfering the induction coil.

4. The apparatus of claim 1, wherein each sensing module further includes a third 5 switching unit and a fourth switching unit, for grounding the induction coil.

5. The apparatus of claim 1, wherein the induction coil further comprises a plurality of parallel connected coils to enhance magnetic flux.

6. The apparatus of claim 1, wherein only one of the first switching units of the sensing modules perform a connection operation at a time.

7. The apparatus of claim 1, wherein the capacitor includes a fixed capacitor and a second variable capacitor, and the second variable capacitor is provided for adjusting a second capacitance to change the magnetic flux.

8. The apparatus of claim 1, wherein the identification module positions the RFID tag according to a position of the first induction coil.

9. The apparatus of claim 1, wherein the circuit modules have a length substantially equal to each other for reducing error of inductance of all induction coils.

10. A radio frequency identification (RFID) positioning method, comprising the steps of:

(a) providing a RFID positioning apparatus, and the apparatus comprising a transmission module, at least one capacitor, a plurality of sensing modules, an identification module and a plurality of circuit modules, and each sensing module having a first switching unit and at least one induction coil, and each circuit module being connected to the transmission module, one of the sensing modules, the capacitor and the identification module, and the circuit modules having a length substantially equal to each other;

(b) transmitting a frequency by the transmission module;

(c) performing a connection operation to the first switching unit of one of the sensing modules and a disconnection operation to the others of the first switching units;

(d) forming a magnetic flux of the first induction coil and the capacitor by the connection operation, wherein the first induction coil senses an identification signal of a RFID tag according to the magnetic flux;

(e) transmitting the identification signal through one of the circuit modules; and

(f) using the identification module to receive the identification signal, for identifying and positioning the RFID tag.

11. The method of claim 10, further comprising a Step (g) of setting up a second switching unit in each sensing module after the Step (f), for avoiding two identification signals from transmitting to the identification module at the same time.

12. The method of claim 11, further comprising a Step (h) of using a grounding unit in each sensing module after the Step (g) to avoid other induction coils from interfering the induction coil.

13. The method of claim 12, further comprising a Step (i) of setting up a third switching unit and a fourth switching unit in each sensing module after the Step (h), for grounding the induction coil.

14. The method of claim 10, wherein the capacitor includes a fixed capacitor and a second variable capacitor, and the second variable capacitor is provided for adjusting a second capacitance to change the magnetic flux.

15. The method of claim 10, wherein the identification module positions the RFID tag according to a position of the first induction coil.

16. The method of claim 10, wherein the circuit modules have a length substantially equal to each other, for reducing error of induction of all induction coils.