Radio tag evaluation system and method

• US 20070046472A1
• Filed: 08/23/2006
• Published: 03/01/2007
• Est. Priority Date: 08/26/2005
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Yamashita, Seiichi
• Granted Patent: US 7,609,164 B2
• Time in Patent Office: Days
• US Class Current: 340/572.100
• CPC Class Codes: G01R 29/10 Radiation diagrams of antennas
• CPC Class Codes: G01S 7/40 Means for monitoring or calibrating
• 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
• CPC Class Codes: G06K 7/0095 Testing the sensing arrangement, e.g. testing if a magnetic card reader, bar code reader, RFID interrogator or smart card reader functions properly testing of electrical circuits G01R31/28
• 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: G06K 7/10465 the interrogation device being capable of self-diagnosis, e.g. in addition to or as part of the actual interrogation process testing of electrical circuits in general G01R31/28

Abstract

A radio tag evaluation system includes a transmission member providing a frequency signal to a radio tag. A transmitting antenna, which is placed on one side of the radio tag for transmiting the inquiry signal supplied from the transmission member. The radio tag is placed and supported around the center of an anechoic box. A receiving antenna is placed on the other side of the radio tag. A reception member is connected to the receiving antenna for analyzing a response signal. The transmitting antenna and the receiving antenna are placed orthogonally to each other, and the primary face of the radio tag is placed substantially at an angle of 45 degrees with respect to the transmitting antenna. The receiving antenna is unable to directly receive a transmission radio wave which has passed around the radio tag. Accordingly, a response signal emitted from the radio tag can be relatively strongly received.

Claims

1. A radio tag evaluation system evaluating a radio tag on the basis of a response signal outputted in response to an inquiry signal, the system comprising:

transmission means providing, as a transmission wave, a frequency signal which includes the inquiry signal to the radio tag;

a transmitting antenna, which is placed at a predetermined distance from the radio tag on one side of the radio tag, and which transmits the inquiry signal supplied from the transmission means, the radio tag being placed around the center of an anechoic box;

a receiving antenna, which is placed at a predetermined distance from the radio tag on the other side of the radio tag, and which receives the response signal transmitted from the radio tag in response to the inquiry signal; and

reception means, which is connected to the receiving antenna, and which analyzes the response signal.

2. The radio tag evaluation system according to claim 1, wherein the transmitting and receiving antennas are placed orthogonally to each other, and

wherein a primary face of the radio tag is placed substantially at 45 degrees to the transmitting and receiving antennas.

3. The radio tag evaluation system according to claim 1, wherein the transmitting antenna and the receiving antenna are dipole antennas with a length equal to half of a wavelength of the transmission wave.

4. The radio tag evaluation system according to claim 2, wherein the transmitting antenna and the receiving antenna are dipole antennas with a length equal to half of a wavelength of the transmission wave.

5. The radio tag evaluation system according to claim 1, and further comprising:

distribution means distributing the transmission wave transmitted from the transmission means to a side of the transmitting antenna and the other side thereof;

conversion means converting a phase and amplitude of part of the transmission wave distributed to the other side; and

addition means adding the part of the transmission wave converted by the conversion means to a wave received by the receiving antenna.

6. The radio tag evaluation system according to claim 2, and further comprising:

distribution means distributing the transmission wave transmitted from the transmission means to a side of the transmitting antenna and the other side thereof;

conversion means converting a phase and amplitude of part of the transmission wave distributed to the other side; and

addition means adding the part of the transmission wave converted by the conversion means to a wave received by the receiving antenna.

7. The radio tag evaluation system according to claim 3, and further comprising:

distribution means distributing the transmission wave transmitted from the transmission means to a side of the transmitting antenna and the other side thereof;

conversion means converting a phase and amplitude of part of the transmission wave distributed to the other side; and

addition means adding the part of the transmission wave converted by the conversion means to a wave received by the receiving antenna.

8. The radio tag evaluation system according to claim 5, wherein the conversion means imparts an opposite phase to the part of the transmission wave distributed to the other side, the opposite phase being opposite to that of a signal obtained by eliminating the response signal from the signal received from the receiving antenna to the addition means.

9. The radio tag evaluation system according to claim 8, wherein the conversion means adjusts the amplitude of the part of the transmission wave, which is distributed to the other side, to the same amplitude or to the substantially same amplitude as the amplitude of the signal obtained by eliminating the response signal from the signal received from the receiving antenna to the addition means.

10. The radio tag evaluation system according to claim 1, wherein the reception means is a time series spectrum analyzer.

11. The radio tag evaluation system according to claim 2, wherein the reception means is a time series spectrum analyzer.

12. The radio tag evaluation system according to claim 3, wherein the reception means is a time series spectrum analyzer.

13. The radio tag evaluation system according to claim 5, wherein the reception means is a time series spectrum analyzer.

14. The radio tag evaluation system according to claim 8, wherein the reception means is a time series spectrum analyzer.

15. The radio tag evaluation system according to claim 9, wherein the reception means is a time series spectrum analyzer.

16. A radio tag evaluation system adapted to evaluate a radio tag on the basis of a response signal outputted in response to an inquiry signal, the system comprising:

a transmission member providing a frequency signal which includes the inquiry signal;

a transmitting antenna positioned at a predetermined distance from a radio tag for transmitting the inquiry signal supplied from the transmission member;

a receiving antenna positioned at a predetermined distance from the transmitting antenna on another side of a radio tag from the transmitting antenna for receiving the response signal transmitted from a radio tag in response to the inquiry signal; and

a reception member being connected to the receiving antenna for analyzing the response signal.

17. The radio tag evaluation system according to claim 16, wherein the transmitting and receiving antennas are placed orthogonally to each other, and

wherein a primary face of a radio tag is placed substantially at 45 degrees to the transmitting and receiving antennas.

18. The radio tag evaluation system according to claim 16, wherein the transmitting antenna and the receiving antenna are dipole antennas with a length equal to half of a wavelength of the transmission wave.

19. A radio tag evaluation method for evaluating a radio tag on the basis of a response signal outputted in response to an inquiry signal, comprising the steps of:

placing the radio tag around the center of an anechoic box;

placing a transmitting antenna at a predetermined distance from the radio tag on one side of the radio tag;

placing a receiving antenna at a predetermined distance from the radio tag on the other side of the radio tag;

transmitting the inquiry signal to the radio tag from transmission means connected to the transmitting antenna; and

analyzing the response signal with reception means connected to the receiving antenna.

20. The radio tag evaluation method according to claim 19, wherein the reception means is a time series spectrum analyzer.