Device and Method for Analysing Radio-Frequency Systems

• US 20100176927A1
• Filed: 01/30/2007
• Published: 07/15/2010
• Est. Priority Date: 01/30/2006
• Status: Active Grant

• Current Assignee: Voyantic Oy
• Original Assignee: Voyantic Oy
• Inventors: Partanen, Juho, Voutilainen, Jukka
• Granted Patent: US 8,461,967 B2
• Time in Patent Office: Days
• US Class Current: 340/10.300
• 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 7/10465 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

The invention relates to a device for analysing radio-frequency systems. Such a device comprises means for detecting radio-frequency electromagnetic signals, and means for determining at least one analog property of the radio-frequency signal received form the reader. According to the invention, the device further comprises means for producing an electromagnetic excitation signal in order to excite the radio-frequency tag, and means for determining at least one analog property of the return signal received from the radio-frequency tag. The device permits the effective analysis of RFID systems, for example, in system-installation and error-searching situations.

Claims

1. Device for analysing radio-frequency systems, which comprise at least one radio-frequency tag and at least one reader for reading wirelessly the information content of the said radio-frequency tag, and which device comprises

means for detecting radio-frequency electromagnetic signals, and

means for determining at least one analog property of the radio-frequency signal received form the reader,

means for producing an electromagnetic excitation signal in order to excite the radio-frequency tag, and

means for determining at least one analog property of the return signal received from the radio-frequency tag.

2. Device according to claim 1, wherein the said analog property of the signal received from the reader is one of the following:

the signal'"'"'s strength, the signal'"'"'s frequency, the signal'"'"'s phase.

3. Device according to claim 1, wherein the said analog property of the return signal received from the radio-frequency tag is one of the following:

the signal'"'"'s strength, the signal'"'"'s frequency, the signal'"'"'s phase.

4. Device according to claim 1, further comprising means, preferably an adjustable attenuator, for equalizing the strengths of the signal received from the reader and the return signal received from radio-frequency tag.

5. Device according to claim 1, comprising means for producing a varying frequency radio-frequency signal and means for dividing the power of the varying frequency signals in order to produce an excitation signal and to determine the analog properties of the signal received from the reader and received from the radio-frequency tag.

6. Device according to claim 1, wherein the means for producing an excitation signal are arranged to produce a broadband signal and the means for determining at least one analog property of the return signal are arranged to convert the return signal to a frequency domain.

7. Device according to claim 1, wherein the device is arranged to measure the activation threshold of the radio-frequency tag, preferably as a function of the frequency.

8. Device according to claim 1, comprising means for analysing the modulation contained in the signal received from the reader or the signal received from the radio-frequency tag.

9. Device according to claim 8, wherein the analysis of the signal modulation comprises the determining of the rise and fall times of the modulation.

10. Device according to claim 1, comprising means for determining at least one analog property of the reader, on the basis of at least one analog property of the signal received from reader.

11. Device according to claim 1, comprising means for determining at least one analog property of the radio-frequency tag, such as its frequency response, its resonance frequency, its quality factor, or the field strength required to perform a command, on the basis of the said at least one return signal received from the radio-frequency tag, or the return signal and an excitation signal produced to excite the radio-frequency tag.

12. Device according to claim 1, comprising in addition means for processing the digital information contained in signals received from the reader or the radio-frequency tag.

13. Device according to claim 1, which comprises means for analysing the quality of the transfer link of the signal, for example, the number of bit errors.

14. Device according to claim 1, comprising in addition means for modulating the excitation signal.

15. Device according to claim 14, wherein the means for producing the excitation signal and the means for modulating the excitation signal can be arranged to produce a response signal to the reader, triggered by the signal received from the reader.

16. Device according to claim 1, comprising a micro-controller, which is arranged to control the means for producing the excitation signal and to analyse the said properties of the received signals.

17. Device according to claim 1, comprising an antenna or antenna connector and means from adjusting the properties or the matching of the antenna.

18. Device according to claim 16, wherein the micro-controller is arranged to adjust the properties and matching of the antenna, on the basis of the properties of the signal measured from the tag.

19. Device according to claim 1, comprising means for evaluating the compatibility of the tag and the reader, by comparing at least one property of the tag with at least one property of the reader.

20. Device according to claim 1, comprising means for configuring the excitation signal on the basis of the signal received from the reader.

21. Device according to claim 1, which is portable and comprises a case, in which all the components of the device are fitted integrally.

22. Method for analysing radio-frequency systems, which comprise at least one radio-frequency tag and at least one reader for reading wirelessly the information content of the said radio-frequency tag, which method comprises the following steps:

(a) a first excitation signal is created in the vicinity of the radio-frequency tag,

(b) the analog response of the radio-frequency tag caused by the first excitation signal is measured,

(c) the analog properties produced by the second excitation signal produced by the said reader are measured,

wherein the stages (a), (b), and (c) are performed using a single device and the method comprises in addition a stage, in which

(d) the analog properties of the second excitation signal are compared with the analog response of the radio-frequency tag, in order to evaluate the compatibility of the reader and the radio-frequency tag.

23. Method according to claim 22, wherein, with the aid of stages (a) and (b), the activation threshold of the radio-frequency tag is measured, preferably as a function of frequency.

24. Method according to claim 22, wherein the analog properties of the second excitation signal are measured at several points in the vicinity of the said reader and are compared with the analog response of the radio-frequency tag.

25. Method according to claim 23, wherein stage (d) too is performed using the said device.

26. Method according to claim 25, comprising in addition a stage (b2), in which a mathematical model of the tag is created in the device on the basis of the analog response of the radio-frequency tag, and the model is used in stage (d) to evaluate the compatibility of the reader and the radio-frequency tag.

27. Method according to claim 25, comprising in addition a stage (c2), in which on the basis of the analog properties of the second excitation signal a mathematical model of the reader is created in the device and the model is used in stage (d) in order to evaluate the compatibility of the reader and the radio-frequency tag.

28. Method according to claim 23, wherein

the desired analog properties of the tag are determined with the aid of stages (a) and (b),

the properties or matching of the antenna in the said device are adjusted to correspond to the analog properties of the tag,

in stage (c), the adjusted antenna is measured, using the strength of the signal induced in the antenna by the field of the reader at least one point and further the strength of the signal obtained through the adjusted antenna is measured,

in stage (d), it is determined whether the signal is sufficiently great for the tag to function.

29. Method according to claim 23, wherein a portable device, preferably is used as said device.