WO2010057263A1 - Système de transpondeur à radiofréquences - Google Patents

Système de transpondeur à radiofréquences Download PDF

Info

Publication number
WO2010057263A1
WO2010057263A1 PCT/AU2009/001514 AU2009001514W WO2010057263A1 WO 2010057263 A1 WO2010057263 A1 WO 2010057263A1 AU 2009001514 W AU2009001514 W AU 2009001514W WO 2010057263 A1 WO2010057263 A1 WO 2010057263A1
Authority
WO
WIPO (PCT)
Prior art keywords
antenna
transponder
radio frequency
signals
frequency
Prior art date
Application number
PCT/AU2009/001514
Other languages
English (en)
Inventor
Nemai Chandra Karmakar
Isaac Balbin
Original Assignee
Monash University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from AU2008906011A external-priority patent/AU2008906011A0/en
Application filed by Monash University filed Critical Monash University
Priority to CN2009801553023A priority Critical patent/CN102317810A/zh
Priority to NZ593545A priority patent/NZ593545A/en
Priority to EP09827052.3A priority patent/EP2366120A4/fr
Priority to CA2743955A priority patent/CA2743955A1/fr
Priority to AU2009317877A priority patent/AU2009317877B2/en
Publication of WO2010057263A1 publication Critical patent/WO2010057263A1/fr
Priority to US13/111,849 priority patent/US9164169B2/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/12—Supports; Mounting means
    • H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
    • H01Q1/2208—Supports; Mounting means by structural association with other equipment or articles associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems
    • H01Q1/2225—Supports; Mounting means by structural association with other equipment or articles associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/74—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
    • G01S13/75—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems using transponders powered from received waves, e.g. using passive transponders, or using passive reflectors
    • G01S13/751—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems using transponders powered from received waves, e.g. using passive transponders, or using passive reflectors wherein the responder or reflector radiates a coded signal
    • G01S13/753—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems using transponders powered from received waves, e.g. using passive transponders, or using passive reflectors wherein the responder or reflector radiates a coded signal using frequency selective elements, e.g. resonator
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/74—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
    • G01S13/82—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems wherein continuous-type signals are transmitted
    • G01S13/825—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems wherein continuous-type signals are transmitted with exchange of information between interrogator and responder
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
    • G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
    • G06K19/067—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
    • G06K19/07—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips
    • G06K19/077—Constructional details, e.g. mounting of circuits in the carrier
    • G06K19/07749—Constructional details, e.g. mounting of circuits in the carrier the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/24—Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/0407—Substantially flat resonant element parallel to ground plane, e.g. patch antenna
    • H01Q9/0442—Substantially flat resonant element parallel to ground plane, e.g. patch antenna with particular tuning means

Definitions

  • the present invention relates to a radio frequency transponder, a radio frequency transponder system, and a process performed by the system.
  • the transponder is passive and the system may be used for identifying and tracking items where the transponders are in close proximity, such as when applied to books of libraries.
  • Radio frequency identification (RFID) systems are based around the use of an RFID tag which is a radio frequency transponder attached to an object and used to store a unique identification code for the object. The code is read from the tag by an RFID reader of the system.
  • RFID systems employed in libraries use an RFID tag that includes an antenna and a microcontroller semiconductor chip that stores the unique identification code for the tag.
  • RFID systems In Australia, only about 6% of public libraries currently use RFID systems for identifying the items they hold. It is considered that one of the reasons for the relatively low adoption of RFID systems within libraries is the cost of the tags.
  • the primary cost associated with tags including microcontrollers is the microcontroller itself.
  • a "chipless" RFID tag uses a transponder that is passive in that it does not include any active processing circuitry, such as a microcontroller. The absence of a microcontroller significantly reduces the cost.
  • a chipless RFID system should have a reasonable read range (e.g. > 30cm) and use tags that are small in size, flexible and printable to reduce cost.
  • Surface acoustic wave RFID tags have been adopted, but are rigid and bulky making them unsuitable for many applications, particularly in libraries where the items, or assets, with tags are stacked in arrangements where the tags are in close proximity.
  • a chipless RFID tag which consists of a set of resonant dipoles and when interrogated is able to provide a signal that represents an RF barcode.
  • the tag relies solely on a series of printed dipoles terminated in variable capacitors that create a series of resonant peaks that can be detected by a reader when interrogated.
  • Another chipless tag that has been proposed includes a series of fractal structures where each is resonant at a different frequency and similarly can produce a backscattered signal when interrogated that represents a unique code. Detection, however, is based on backscattered amplitude which can be unreliable for many applications, particularly in libraries. Difficulties also arise in printing the proposed tags, such as when the tag includes structures gap-coupled to a microstrip line of the tag.
  • chipless printable RFID tags that have been proposed are their limited information carrying capacity (only 8 bits for time domain responses and 34 bits for frequency domain responses) and the efficiency and accuracy of the RFID readers used with the tags.
  • the reader systems should be able to: (i) compensate for the limited capacity of information that can be extracted from a chipless RFID tag; (ii) read multiple chipless tags in close vicinity; and (iii) discriminate between the items the tags are applied to quickly and efficiently.
  • the present invention provides a radio frequency transponder, including: a substrate; and at least one planar antenna on said substrate, said antenna having a shape determining a corresponding resonant frequency of said antenna; wherein said antenna causes a phase difference between backscattered signals generated in response to excitation of said antenna by orthogonally polarised interrogation signals at said resonant frequency, and said phase difference represents a code of said antenna.
  • the present invention also provides a radio frequency transponder system, including: the transponder; and a reader for generating the interrogation signals and reading the backscattered signals to extract said code.
  • the present invention also provides a radio frequency reader for interrogating a radio frequency transponder, including: a frequency interface unit for transmitting polarised interrogation signals and receiving backscattered signals from the transponder in response; and a signal processing unit for determining a code of the transponder from phase difference of said backscattered signals.
  • the present invention also provides a radio frequency process, including: transmitting polarised interrogation signals; receiving backscattered signals from a transponder in response; and determining a code of the transponder from phase difference of said backscattered signals.
  • Figure 1 is a block diagram of an embodiment of a radio frequency transponder system according to the present invention
  • Figure 2 is a diagram of a stub loaded microstrip patch antenna for a tag
  • Figure 3 is a graph of return signal loss against frequency for the antenna of Figure 2;
  • Figure 4 is a graph of the relative phase of the backscattered signal against stub length of the antenna of Figure 2;
  • FIG. 5 is a diagram of an embodiment of a radio frequency transponder according to the present invention.
  • Figure 6 is a graph of the phase difference between backscattered signals in two orthogonal polarisations against absence or presence of stubs on antennas of the transponder of Figure 5, for different resonant frequencies;
  • Figure 7 is a diagram of a dual polarised stub loaded microstrip patch antenna for a tag;
  • Figure 8 is a graph of return and insertion losses against frequency for the antenna of Figure 7;
  • Figure 9 is a radiation pattern for the antenna of Figure 7;
  • Figure 10 is a graph of the phase of the backscattered signal against frequency and for different stub lengths for the antenna of Figure 7;
  • Figure 11 is a diagram of a two-by-two array of patch antennas of Figure 7;
  • Figure 12 is a graph of radiation characteristics (boresight gain and side lobes) against element separation for the array of Figure 11 in a Corners layout;
  • Figure 13 is a radiation pattern for the array of Figure 11 ;
  • Figure 14 is a graph of radiation characteristics (boresight gain and side lobes) against element translation distance for positions of antennas in the array;
  • Figure 15 is a graph of radiation characteristics (boresight gain and side lobes) against element separation for the array of Figure 11 in a NSEW layout
  • Figure 16 is a graph of the phase of the backscattered signal from the array against frequency and relative to stub length;
  • Figure 17 is a graph of backscattered phase difference against stub length for the antenna of Figure 7 and the array of Figure 11 ;
  • Figure 18 is a diagram of an embodiment of a chipless transponder with six two- by-two patch antenna arrays, according to the present invention.
  • Figure 19 is a diagram of an embodiment of the radio transponder system
  • Figure 20 is a block diagram of a reader of the radio transponder system
  • Figure 21 is a diagram of an antenna of the reader
  • Figure 22 is a block diagram of the reader reading a number of tags; and Figure 23 is a graph of frequency against time illustrating frequency modulated continuous wave signal analysis for transmitted and received signals of the reader.
  • a radio frequency transponder system 100 is used for radio frequency identification (RFID) applications.
  • the system 100 includes RFID tags 102, at least one RFID reader system 104 for interrogating or reading the tags using radio frequency interrogation or excitation signals, and an application system 106.
  • the application system 106 is a computer system, such as produced by IBM Corporation or
  • the application system 106 stores and runs application and database software to process data provided by a reader 104 and record data associated with the items or assets on which the tags 102 are placed.
  • the RFID Tag The RFID Tag
  • the tags 102 of the system 100 are each a passive and chipless (i.e. without a microcontroller or microprocessor) radio frequency transponder that stores a unique identification code for each tag 102.
  • the code is obtained from the phase data of the back scattered signal from the transponder in two orthogonal polarisation planes when the transponder is excited by radio frequency interrogation signals produced by the reader 104.
  • the tag 102 includes an array of stub loaded microstrip patch antennas printed on a dielectric substrate using electrically conductive ink.
  • the stub loaded microstrip patch antenna (SLMPA) of the tag 102 is based on a microstrip patch antenna 202, shown in Figure 2.
  • the antenna 202 has a quadrilateral shape is printed on a substrate 204, has a length L, width W and a stub 206 which is used to load the antenna.
  • the stub 206 is typically relatively thin with respect to the dimensions of said antenna. According to Y.P. Zhang, "Design and Experiment on Differentially-Driven Microstrip Antennas," IEEE Trans, on AP, vol. 55 no.
  • the antenna 202 is governed by the following equations for a substrate with thickness h , resonant free space wavelength ⁇ 0 and relative permittivity ⁇ r , which enables the length and width to be selected based on a selected values of ⁇ r (i.e. the choice of material), h and ⁇ o .
  • the characteristic impedance of the loading provided by the stub 206 needs to be matched to be the same as the real part of the input impedance of the antenna. This is desirable to maximize the effect that the load will have on the backscattered signal produced when the antenna 202 is excited by the interrogation signal.
  • a 50 Ohm microstrip line is used for the stub 206 and according to Zhang its offset from the centre of the edge of the antenna 202 is given by:
  • the antenna is loaded at its edge with a distributed load rather than a lumped load.
  • the simplest sort of distributed load is an open circuit microstrip stub 206.
  • the impedance of the open circuit microstrip stub 206 of length SL (Stub Length), with characteristic impedance Zo, can be calculated using Richard's Transformation (as discussed in D. M. Pozar, Microwave Engineering, Hoboken, NJ: John Wiley & Sons, 2005) and is given by:
  • ⁇ g is the guided transmission wavelength
  • a SLMPA 202 was designed and simulated using 3D electromagnetic simulation software that provides a full-wave method-of-moments solver.
  • the simulated return loss is shown in Figure 3.
  • the simulated results of Figure 3 show a well matched antenna with a return loss peak of -24.9 dB at 2.4 GHz.
  • the width of the patch 202 gives rise to multiple modes being excited and the fundamental mode for the orthogonal polarization is visible at 2 GHz.
  • the backscattering properties of the SMLPA 202 can be analysed using Radar Cross Section (RCS) analysis.
  • RCS Radar Cross Section
  • the practical operating limits of using backscattered signals from an SLMPA can be analysed by examining the RCS characteristics of the antenna 202 when illuminated with a plane wave linearly polarized in the E-plane.
  • the main phase characteristics of the backscattered signal include a phase shift that depends on the stub length as shown in Figure 4.
  • the phase shift data in Figure 4 is shown relative to the backscattered phase of an SLMPA 202 with no stub loading.
  • the relative phase or phase difference follows a generally linear pattern according to the electrical length of the loading stub. There is some discrepancy due to imperfections in the fabrication however they are not significant.
  • the tag 102 of the transponder system 100 includes a number of SLMPAs 500, as shown in Figure 5, which have different respective resonant frequencies to enable the backscattered signal from each antenna 500 of the tag to be isolated or separated from each other.
  • the tag 102 is interrogated in two orthogonal planes using two excitation interrogation signals and the phase difference between the backscattered signal in the two planes is read and used to encode and determine the data of each antenna.
  • Using a phase difference of two signals avoids fundamental issues associated with environmental conditions where the phase of the signal would change, and also avoids having to determine the spatial position of an antenna 500 or the tag 102.
  • Each SLMPA 500 is configured to resonate at the same frequency in both of the two orthogonal planes (E 1 and E 2 ) of the excitation signal.
  • An SLMPA 500 can be encoded with a single bit of data by loading the antenna with no stub in one plane and a stub of length SL in the other plane.
  • the unique bit of code associated with each antenna 500 can then be extracted by comparing the phase of the backscattered signal in the two polarisation states, which is then digitised by the reader 104 to represent a 1 or 0.
  • the tag 102 comprises of a plurality of SLMPAs 500, as shown in Figure 5, printed using electrically conductive ink on a paper or plastic substrate 502.
  • the antennas 500 are square so that the resonant frequency is the same for the orthogonally polarised excitation signals. Alternatively, the antennas 500 may be polygons of equal sides to exhibit this characteristic.
  • the antennas 500 are of different lengths to correspond to respective different resonant frequencies.
  • the antennas are each loaded by a respective meandering stub 504 having a stub length SL.
  • the antennas 500 are printed adjacent each other with set spacing between them. Rather than simply loading the edge of each antenna with the stub, as shown in Figure 2, an insert feed is used for each stub 504.
  • each antenna 500 is characterised by two parallel rectangular recess sections in the antenna 500 to define an insert strip 506 having an insert length IL and an insert width IW.
  • the insert 506 is edge loaded by the meandering stub 504.
  • the stub 504 is a microstrip line that meanders away from and back towards the antenna 500 to improve spatial efficiency and to increase the stub's characteristic impedance, allowing larger impedances to be achieved with shorter overall stub lengths.
  • a transponder with three square SLMPAs 500 with side lengths (and widths) 38 mm, 41 mm and 44 mm and a spacing of 1 mm was constructed so as to provide antennas with respective resonant frequencies of 2.52 GHz, 2.33 GHz and 2.17 GHz in both orthogonal planes.
  • a meandering stub 504 of length 10.9 mm and width 0.2 mm was added to represent and encode a 1 bit, whereas the absence of any loading stub on the antenna 500 was used to represent a 0 bit.
  • the transponder was interrogated with linearly polarised interrogation signals having E field vectors oriented in the directions El and E2, as shown in Figure 5.
  • phase difference at boresight in the electric field was taken at 1 m, and the results obtained are shown in Figure 6 when different combinations of absence and presence of the stub 504 were used.
  • the phase difference read by the reader 104 varies between 0 to 180°, and by using this entire phase difference a single antenna 500 of the tag 102 can be used to encode additional digital information.
  • a single antenna 500 can produce code comprising a hexadecimal digit if phase differences with a separation of 11.25° are detected.
  • Encoding this phase difference with sufficient separation is achieved by changing the loading of the antenna by adjusting the length of the stub 504, for example by 1 to 2 mm for the example transponder. Therefore at each resonant frequency a hexadecimal digit can be obtained from the tag 102.
  • An RFID tag 102 with n antennas 500 resonant at different frequencies f/, f? ... ⁇ n -i, f « in an array configuration, as shown in Figure 5 allows n hexadecimal digits to be obtained by the reader 104 when the tag 102 is interrogated by the orthogonally polarised excitation signals E 1 and E 2 .
  • the reader 104 scans across the frequencies f; to f n to extract a codeword (or barcode) comprising the codes of each antenna 500.
  • the codeword represents the unique identification data (or ID) of the tag 102.
  • the reader 104 converts the magnitude of the phase difference of the backscattered signals at each resonant frequency f / to f n into a digital hexadecimal integer comprising a code and repeats the process at the next resonant frequency, until the stop bit of the codeword is found.
  • SLMPA 700 for use in the tag 102 is shown in Figure 7.
  • This SLMPA 700 is square and is loaded with two open circuit stubs 702 and 704 whose lengths are orthogonal to one another and extend from respective and adjacent sides of the patch antenna 700.
  • This antenna 700 is dual-resonant and will exhibit a maximum antenna mode RCS at the desired resonant frequency by selecting the lengths and the characteristic impedance of the stubs, as discussed below.
  • the antenna 700 has the advantage that it allows the signals in the H plane to also be utilised as a reference and provide greater discrimination.
  • the SLMPA 700 is again fabricated of conductive material and placed on a dielectric substrate 706 which is placed on a conductive ground plane 708.
  • the return loss obtained for the SLMPA 700 is shown in Figure 8, where the S 11 and S 22 plots are the same and the S 21 and S 12 plots are the same and the subscripts represent the input and output ports examined.
  • the two-dimensional radiation patterns for the backscattered signals in both the E and H planes are shown in Figure 9. This shows a good return loss of -22.2 dB at 6.12 GHz for both ports, and transmission leakage of power from one port to the other of -31.3 dB.
  • the antenna has a gain of 4.4 dBi, and the radiation pattern shows a main lobe radiating in the outward no ⁇ nal direction of the patch (boresight).
  • the RCS can be varied with respect to frequency and create a frequency spectrum where distinct changes in the phase and amplitude are observable.
  • the RCS consists of two components referred to as the antenna mode scattering and the structural mode scattering.
  • the structural mode scattering is an unavoidable portion of the RCS that occurs due to the structure of the SLMPA itself, and exists for all possible radar targets. In general this scattering component does not exhibit a phase difference between its orthogonally polarized components.
  • the antenna mode is a function of the radiation characteristics of the antenna itself and is designed using standard antenna theory, as described above.
  • the two scattering component parameters are defined with respect to the total electric field scattered from an antenna given by the following, as discussed in C. A. Balanis, Antenna Theory: Analysis and Design, 2 nd edition, Hoboken, NJ: John Wiley & Sons, 2005 ("Balanis").
  • E S (Z L ) The electric field scattered by the antenna when it is loaded with an impedance of Z L
  • I m * The current induced when the antenna is in transmitting mode with a conjugate match
  • I 1 The current induced when the antenna is in transmitting mode
  • T * The conjugate matched reflection co-efficient
  • E' The time- varying electric field
  • Equation (9) represents the antenna mode scattering
  • the structural mode for the SLMPA 700 this can be determined by providing the antenna 700 with different loading stub lengths.
  • the structural mode was found to be almost constant across the frequency band except for a clear resonant dip at 6.12 GHz. Outside of the resonant band the scattering consists of only the structural mode component, while in the band it is a combination of both the antenna and structural mode components. The resonance appears as a null in the RCS indicating destructive interference between the two scattering components.
  • the phase response showed a smooth pattern except in the resonant band where a steady increase in the phase is observed as the loading stub is extended.
  • an array of SLMPAs is used.
  • SLMPAs For a two-by- two array 1100, as shown in Figure 11, there are a number of factors that affect the overall radiation characteristics of the structure. These include the layout of the array (linear, planar etc.), the distance between the elements and the excitation amplitude and phase of each element.
  • the transponder 102 is illuminated with a plane wave with uniform magnitude and phase and so the excitation amplitude and phase are equal.
  • the array 1100 consists of four identical SLMPAs 700 in a North, South, East, West (NSEW) layout as shown in Figure 11.
  • the elements 700 are arranged symmetrically along a square of side length S.
  • the inter-element spacing is described by the parameter S and the element orientation is described by the translation parameter D, which has values from -0.5*S to 0.5*S.
  • the translation described by the parameter D for each element is in the clockwise direction indicated in Figure 11.
  • the transponder ground plane is square shaped so that the structural mode scattering in each orthogonal polarization is equal, and its edge length is G.
  • the total radiated field as a product of the single element radiation pattern and the Array Factor (AF) is:
  • the array factor is given by the following, as discussed in Balanis.
  • Equation (13) is the same array factor as for a standard 2x2 planar array with an inter- element separation of S.
  • the normalized form can be expressed as
  • Equations (15) and (19) show that the larger the separation between the elements defined by the parameter S, the smaller the angle ⁇ where the 1 st grating lobe will occur. In other words the closer the elements are to each other than the better the sidelobe performance 0 will be. Also, the NSEW layout should have its optimum size with larger values of S since there is a factor of 2 in equation (19) that does not exist in equation (15).
  • the performance of the 2x2 SLMPA array 1100 was simulated using the full- wave method-of-moments solver, and the radiation characteristics of the structure relate directly 5 to the antenna mode scattering component.
  • the array 1100 was illuminated by a uniform plane wave, and so the excitation for each port was uniform with no phase offset, and to make the result comparable with that for a single SLMPA 700 only 25% of the power used previously was delivered to the whole array 1100.
  • the antenna array showed an improved maximum gain of 10.2 dBi with a side lobe of -13.9 dB, as shown in Figure 12.
  • the side lobe level becomes larger as the element separation moves beyond half of the free space wavelength, and then multiple side lobes begin to appear.
  • the antenna main beam gain is over 10 dBi when 0.5* ⁇ ⁇ S ⁇ ⁇ , as shown in Figure 12, while the side lobe level remains below -3 dB.
  • the structural mode scattering is dependent on the overall size of the structure including the substrate and the ground plane. If the structure of the tag 102 is too large then the antenna mode scattering component will be too small compared with the structural mode scattering component and no longer observable. As the edge length G is increased the structural mode scattering increases significantly and the resonance is increasingly difficult to observe. Also, when the ground plane size is too small the radiation of the elements is disturbed at the edges.
  • the transponder 1800 includes 24 SLMPA patch elements 700 and was designed to operate in the UWB spectrum from 3.1 to 10.9 GHz.
  • the transponder 1800 contains six resonant frequency signatures over the band from 4.5 to 6.75 GHz.
  • the six-signature chipless RFID transponder 1800 includes optimally matched SLMPAs 700 at six resonant frequencies that do not interfere, and their parameters are listed in Table 1 below. Given the optimal spacing distance (S) for the Corners layout is larger than for the NSEW layout, the SLMPA arrays with shorter resonant wavelengths are placed at a smaller S, and with D closer to 0.
  • the transponder 1800 is symmetric for all resonant frequencies. Also, the non-radiating elements are placed or positioned so their mutual coupling effects are symmetric as well, and cancel each other out. This produces a main radiated beam for each resonant frequency that is aligned directly to boresight, with almost equal beamwidths for all resonant frequencies. This is significant as it enables each antenna array and thus the transponder 1800 to be read from a fixed location.
  • the six sets of 2x2 SLMPA arrays are labelled with a number that indicates their patch width (9,10,11,12,13,14 mm).
  • the highest frequency (smallest size) SLMPAs are placed on the inner layer which has space for two sets of 2x2 SLMPA arrays (9, 10 mm).
  • the outer layer includes the remaining four sets of 2x2 SLMPA arrays with the highest frequency array of these (11 mm) placed in the NSEW orientation, and the lowest frequency array (14 mm) in the Corners orientation.
  • the intermediate frequency arrays (12, 13 mm) are placed in between NSEW and Corners layouts with
  • the transponder was also used in an experimental environment based on the operating principles described above, and a summary of the experimental results is shown below in Table 3.
  • the above shows an average measured phase shift of 41° at each signature frequency for the transponder 1800, and confirms the backscattered phase difference for each frequency signature can be controlled by adjusting the lengths of loading stubs of the antenna elements of the arrays.
  • the transponder size can be considerably reduced, such as to the size of a credit card or smaller.
  • a tag 102 of this size can be fabricated on a plastic or paper substrate by printing the patch with conductive ink using a flexography printing process.
  • the stubs of the patches need to be varied for each tag 102 and to reduce cost are printed using conductive ink and an inkjet printing process.
  • the ground plane can be printed, like the patch, using conductive ink and a flexography process.
  • the transponder system 100 utilizes two orthogonal polarization states during both transmission and reception when interrogating the tag.
  • the separate polarizations can be provided at the reader 104 with a single dual-polarized antenna, or two separate orthogonally polarized antennas (Ap 1 and Ap 2 for polarization states Pl and P2 respectively) as shown in Figure 19.
  • the system can also function using a mono-static setup where the same antennas are used for transmission and reception or in a bi-static setup, as shown in Figure 19 where separate antennas are used for transmission (Ap 1 T and and reception (Ap 11 R and A P2 , R ).
  • the reader 104 generates the interrogation signal, (Ip 1 (f) and at a frequency, / (GHz), and then divides the power equally between Ap 1; ⁇ and Ap 2 T.
  • Ip 1 (f) the interrogation signal
  • / (GHz) the frequency
  • Ap 1; ⁇ and Ap 2 T the frequency that are now two signals that propagate through free space towards the tag 102.
  • the signals reach the transponder and are scattered according to its Radar Cross Section (RCS) characteristics.
  • the tag 102 is designed so that the RCS characteristics differ in the orthogonal polarization states Pl and P2, as discussed above.
  • the phase shift is set so that the return signals (Rp 1 (f) and Rp 2 (f)) that propagate back towards the reader have a phase difference of,
  • phase signatures that are used to obtain digital data from the return signals at each resonant frequency. For example, for 7 frequency signatures, each frequency signature will contain a discrete phase difference between 0 - 180°, and each phase signature is resolved to the nearest 10° creating 18 possible combinations for each frequency signature instead of the standard 2 combinations (binary).
  • ⁇ N can be generated as defined in Equation (20).
  • the number of represented bits is at least equal to the highest integer value equal to or less than (i.e. the "floor” of) a product of: the number of frequency signatures; and the base-2 logarithm of the number of bins.
  • the number of bins is determined by the total detachable phase angle (180°) divided by the resolution of the bins (To).
  • the reader 104 operates at microwave frequencies, and includes a planar array transmit and receive antenna 2002, a high frequency interface unit 2004 connected to the antenna 2002, and a digital control unit 2006 connected between the application system 106 and the high frequency interface unit 2004.
  • the digital control unit 2006 includes microcontroller circuitry to perform digital signal processing on the data obtained from the RFID transponder 102 and to also control transmission of interrogation signals generated by the high frequency interface unit 2004.
  • the control unit 2006 enables the reader 104 to communicate with the transponders 102 wirelessly by performing modulation and anti-collision procedures and decoding the received data from the transponders 102.
  • the unit 2006 includes a microprocessor 2008, a memory block 2010, analog-to-digital converters 2012 and a communications interface 2014 for connecting to the application system 106.
  • the HF interface unit 2004 transmits and receives radio frequency (RF) signals, and includes two separate signal paths to correspond with the two directional data flows from and to the transponder 102.
  • a local oscillator 2050 (LO) generates the RF carrier signal, which is amplified by a power amplifier 2054, and the amplified signal is transmitted through the antenna 2002.
  • a directional coupler 2056 separates the reader's transmitted signals and the received weak backscattered signals from the tag 102.
  • the directional coupler consists of two continuously coupled homogenous transmission lines, and if all ports are matched, the power of the incoming and outgoing signals is divided in the coupler.
  • the received backscattered signal is weak and a low noise amplifier 2058 increases the signal's amplitude before it is fed to an RF mixer 2052 with the signal generated by the local oscillator 2050 to produce an intermediate frequency signal.
  • the intermediate frequency signal is processed by a gain and phase detector 2060 to generate received data for the digital control unit 2006.
  • the HF interface unit 2004 is protected from EM interference using metal cages.
  • the antenna 2002 includes two phased array antennas 2100 which each comprise, as shown in Figure 21: (i) a 3x2 element phased array antenna panel; and (ii) associated beamforming modules, as discussed in N.C. Karmakar, "Smart Antennas for Automatic
  • Each beamforming module is a 4 bit digital phase shifter array to control the beam in a three dimensional (3D) plane.
  • the phase shifter arrays connect to individual element of the array antenna, control the values of ⁇ x and ⁇ y in Equation (11) which are the individual x- and y-plane phase shifts of elements, thus enabling beamforming in a 3D plane.
  • ⁇ x and ⁇ y in Equation (11) which are the individual x- and y-plane phase shifts of elements, thus enabling beamforming in a 3D plane.
  • two sets of the beamforming modules or networks including the two array antennas 2100 are operated coherently.
  • the same beamforming networks that are used for transmission are also used for reception.
  • the antennas 2100 are oriented in orthogonal planes for the polarisation diversity as described with reference to Figure 19.
  • Dual-polarised sub-arrays can be used instead of the array elements of the antenna 2100 for high resolution dual -polarised signal transmission and reception.
  • a number of antennas are used in various positions to exploit diversity. For example, in an active three-antenna configuration, a single pole three throw (SP3T) switch activates three adjacent array modules to collimate the in-phase beams in even further fine resolution.
  • SP3T single pole three throw
  • the antenna 2002 can then produce high gain scan coverage in 360° azimuth and elevation plane patterns.
  • the antenna 2002 detects individual RFID tags 102, as shown in Figure 22. The exact bearing of each tag 102 from the reader 104 is calculated from the beam position of the antenna.
  • MUSIC Multiple Signal Classification
  • the interrogating signals from the reader transmit antenna Tx are sent to the tag 102 which returns frequency modulated echoes towards the reader 104 and the receive antenna Rx of the reader 104 receives the modulated echoes.
  • the reader 104 can use frequency modulated continuous wave (FMCW) signals from the transmit antenna Tx, with an instantaneous frequency that varies linearly in time, as shown in Figure 23.
  • FMCW frequency modulated continuous wave
  • the receive antenna Rx receives modulated echoes after a time delay, where the echoes for tags with different resonant frequencies are received at different times, as shown in Figure 23. If the frequency response of the tags are well separated in frequency, the FMCW echo signals will automatically be placed in different frequency bins for separate processing. In the signal processing both amplitude and phase of the radar cross section (RCS) are stored and processed. If the frequency response of the tags are not well separated, and tags' echoes overlap in the received time-frequency spectrum, then the added phases and amplitudes can indicate the number of tags which send the echo signals.
  • RCS radar cross section
  • the phase difference is significant and the phase vector addition of the echo signals is used to determine the presence of the bits encoded in each tag 102.
  • the reader 104 is able to determine the number of tags 102 which are collided in time and frequency spectrum.
  • the received FMCW signals are used to distinguish moving tags 102 from stationary tags 102 by recording any Doppler shift of echo signals and the range of the tags 102.
  • Time-domain windowing techniques are used to enhance the detection quality of echo signals.
  • the reader 104 uses anti-collision measures, such as time of arrival (ToA), direction of arrival (DoA), polarisation diversity (PD), cross correlation of echo signals and frequency chirping of carrier signals, to discriminate between tags 102, particularly those in close proximity.

Landscapes

  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Theoretical Computer Science (AREA)
  • Radar Systems Or Details Thereof (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)

Abstract

L’invention concerne un transpondeur à radiofréquences comprenant un substrat et au moins une antenne plane sur ledit substrat. Selon l’invention, ladite antenne présente une forme qui détermine une fréquence de résonance correspondante de ladite antenne, ladite antenne provoque une différence de phase entre les signaux rétrodiffusés produits en réaction à l’excitation de ladite antenne par des signaux d’interrogation à polarisation orthogonale à ladite fréquence de résonance et ladite différence de phase représente un code de ladite antenne.
PCT/AU2009/001514 2008-11-20 2009-11-20 Système de transpondeur à radiofréquences WO2010057263A1 (fr)

Priority Applications (6)

Application Number Priority Date Filing Date Title
CN2009801553023A CN102317810A (zh) 2008-11-20 2009-11-20 射频应答器系统
NZ593545A NZ593545A (en) 2008-11-20 2009-11-20 Radio frequency transponder system
EP09827052.3A EP2366120A4 (fr) 2008-11-20 2009-11-20 Système de transpondeur à radiofréquences
CA2743955A CA2743955A1 (fr) 2008-11-20 2009-11-20 Systeme de transpondeur a radiofrequences
AU2009317877A AU2009317877B2 (en) 2008-11-20 2009-11-20 Radio frequency transponder system
US13/111,849 US9164169B2 (en) 2008-11-20 2011-05-19 Radio frequency transponder system

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
AU2008906011 2008-11-20
AU2008906011A AU2008906011A0 (en) 2008-11-20 Radio frequency transponder system
AU2009905139 2009-10-21
AU2009905139A AU2009905139A0 (en) 2009-10-21 Radio frequency transponder system

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US13/111,849 Continuation US9164169B2 (en) 2008-11-20 2011-05-19 Radio frequency transponder system

Publications (1)

Publication Number Publication Date
WO2010057263A1 true WO2010057263A1 (fr) 2010-05-27

Family

ID=42197757

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU2009/001514 WO2010057263A1 (fr) 2008-11-20 2009-11-20 Système de transpondeur à radiofréquences

Country Status (7)

Country Link
US (1) US9164169B2 (fr)
EP (1) EP2366120A4 (fr)
CN (2) CN106654517A (fr)
AU (1) AU2009317877B2 (fr)
CA (1) CA2743955A1 (fr)
NZ (1) NZ593545A (fr)
WO (1) WO2010057263A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2992758A1 (fr) * 2012-06-27 2014-01-03 Inst Polytechnique Grenoble Systeme d'identification par frequences radio
US8967485B2 (en) 2009-12-16 2015-03-03 Adant Srl Reconfigurable antenna system for radio frequency identification (RFId)
CN113544691A (zh) * 2018-12-11 2021-10-22 Mhm微技术责任有限公司 通过阻抗变化的射频信号调制
TWI796384B (zh) * 2018-02-05 2023-03-21 美商波音公司 具有用於降低功率消耗的軸對稱薄化的數位波束成形陣列之系統及其製造方法

Families Citing this family (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120249395A1 (en) * 2011-03-30 2012-10-04 Convergence Systems Limited Ultra Thin Antenna
JP6116126B2 (ja) * 2012-03-29 2017-04-19 パナソニック株式会社 レーダ装置
US20130342326A1 (en) * 2012-06-22 2013-12-26 United States Of America As Represented By The Administrator Of The National Aeronautics And Spac Systems, apparatuses, and methods for transparent and ubiquitous sensing technology
US9975483B1 (en) * 2013-02-08 2018-05-22 Amazon Technologies, Inc. Driver assist using smart mobile devices
US9213873B2 (en) * 2013-03-22 2015-12-15 Symbol Technologies, Llc Determining movement of a radio frequency identification tag using a phase difference/frequency model
US11163050B2 (en) 2013-08-09 2021-11-02 The Board Of Trustees Of The Leland Stanford Junior University Backscatter estimation using progressive self interference cancellation
CN103413167A (zh) * 2013-08-11 2013-11-27 章伟 一种具有防伪功能的烟草frid标签
US9278589B2 (en) * 2013-12-16 2016-03-08 GM Global Technology Operations LLC Low line TPMS: sensor association using RSSI and doppler signatures with a single or multiple ECUs
WO2015168700A1 (fr) 2014-05-02 2015-11-05 The Board Of Trustees Of The Leland Stanford Junior University Procédé et appareil à des fins de suivi de mouvement au moyen de signaux radioélectriques
WO2015189846A1 (fr) * 2014-06-10 2015-12-17 Tag & Find Wireless Solutions Ltd. Lecteur rfid et système d'antenne pour localiser des articles au moyen d'un dispositif mobile
CN104899617A (zh) * 2015-04-24 2015-09-09 杨军 基于打印电子的Chipless RFID的3D定位方法
CN109301446A (zh) * 2015-08-20 2019-02-01 江苏省电力公司常州供电公司 馈电方便的超高频电子标签天线
ES2562732B2 (es) * 2015-08-25 2016-06-28 Universidad De Oviedo Sistema y Método para la detección de la orientación de objetos o seres vivos mediante el uso de dispersores electromagnéticos
DE102016113302A1 (de) * 2016-07-19 2018-01-25 Sick Ag RFID-Vorrichtung und Verfahren zum Kommunizieren mit mindestens einem RFID-Transponder
US10338205B2 (en) * 2016-08-12 2019-07-02 The Board Of Trustees Of The Leland Stanford Junior University Backscatter communication among commodity WiFi radios
CN110100464A (zh) 2016-10-25 2019-08-06 小利兰·斯坦福大学托管委员会 反向散射环境ism频带信号
US10739452B2 (en) * 2017-02-27 2020-08-11 Nec Corporation Distance estimation using multiple phase differences
CN107634338B (zh) * 2017-09-12 2021-08-10 惠州Tcl移动通信有限公司 一种双频wifi天线及移动终端
US20190178972A1 (en) * 2017-12-13 2019-06-13 Cypress Semiconductor Corporation Determining angle of arrival of a radio-frequency signal
US11923924B2 (en) * 2018-02-26 2024-03-05 Parallel Wireless, Inc. Miniature antenna array with polar combining architecture
US11372100B2 (en) * 2018-10-23 2022-06-28 Baidu Usa Llc Radar object classification and communication using smart targets
US11551537B2 (en) 2019-04-11 2023-01-10 Nexite Ltd. Wireless dual-mode identification tag
EP3996289A1 (fr) 2019-04-11 2022-05-11 Nexite Ltd. Étiquette d'identification sans fil bimode
CN112448126B (zh) * 2019-08-30 2024-02-09 Oppo广东移动通信有限公司 天线装置及电子设备
CN110943755B (zh) * 2019-12-10 2021-08-10 泰新半导体(南京)有限公司 一种基于结构模和天线模的时频混合射频装置
CN111967563B (zh) * 2020-09-04 2022-02-18 浙江大学 基于mfcc特征编码的组合型超宽带交叉极化无芯片rfid标签
US11635402B2 (en) * 2020-10-26 2023-04-25 Purdue Research Foundation Subsoil moisture monitoring system including battery-less wireless chipless sensors
EP4275160A1 (fr) 2021-01-11 2023-11-15 Nexite Ltd. Opérations sans contact et automatiques d'un magasin de vente au détail
US11797928B2 (en) 2021-12-13 2023-10-24 Nexite Ltd. Dual-antenna, four-armed identification tag

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5045862A (en) * 1988-12-28 1991-09-03 Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of Communications Dual polarization microstrip array antenna
US6861993B2 (en) * 2002-11-25 2005-03-01 3M Innovative Properties Company Multi-loop antenna for radio-frequency identification
US20050280539A1 (en) * 2004-06-22 2005-12-22 Pettus Michael G RFID system utilizing parametric reflective technology
US20060220794A1 (en) * 2005-04-04 2006-10-05 Jeffrey Zhu Phase modulation for backscatter transponders

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4725841A (en) * 1983-06-30 1988-02-16 X-Cyte, Inc. System for interrogating a passive transponder carrying phase-encoded information
US5995046A (en) * 1998-01-30 1999-11-30 Widata Corporation Radio geo-location system with advanced first received wavefront arrival determination
EP1035418B1 (fr) * 1999-02-09 2005-07-27 Magnus Granhed Antenne encapsulée pour transpondeur passif
JP2001034724A (ja) * 1999-06-29 2001-02-09 Xerox Corp バーコード及びバーコードシステム
US7639137B2 (en) * 2005-08-30 2009-12-29 Somnath Mukherjee System for identifying radio-frequency identification devices
JP4794974B2 (ja) * 2005-10-19 2011-10-19 富士通株式会社 タグアンテナ，これを用いるタグ及びｒｆｉｄシステム。
JP4235663B2 (ja) * 2006-11-16 2009-03-11 英一 小川 金属対応無線ｉｃタグ装置
CN102106110A (zh) * 2008-05-22 2011-06-22 惠普开发有限公司 多模态安全威慑物和用于产生该多模态安全威慑物的方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5045862A (en) * 1988-12-28 1991-09-03 Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of Communications Dual polarization microstrip array antenna
US6861993B2 (en) * 2002-11-25 2005-03-01 3M Innovative Properties Company Multi-loop antenna for radio-frequency identification
US20050280539A1 (en) * 2004-06-22 2005-12-22 Pettus Michael G RFID system utilizing parametric reflective technology
US20060220794A1 (en) * 2005-04-04 2006-10-05 Jeffrey Zhu Phase modulation for backscatter transponders

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP2366120A4 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8967485B2 (en) 2009-12-16 2015-03-03 Adant Srl Reconfigurable antenna system for radio frequency identification (RFId)
US9196970B2 (en) 2009-12-16 2015-11-24 Adant Technologies, Inc. Metamaterial reconfigurable antennas
FR2992758A1 (fr) * 2012-06-27 2014-01-03 Inst Polytechnique Grenoble Systeme d'identification par frequences radio
TWI796384B (zh) * 2018-02-05 2023-03-21 美商波音公司 具有用於降低功率消耗的軸對稱薄化的數位波束成形陣列之系統及其製造方法
CN113544691A (zh) * 2018-12-11 2021-10-22 Mhm微技术责任有限公司 通过阻抗变化的射频信号调制

Also Published As

Publication number Publication date
CN102317810A (zh) 2012-01-11
CA2743955A1 (fr) 2010-05-27
CN106654517A (zh) 2017-05-10
EP2366120A4 (fr) 2014-03-12
NZ593545A (en) 2014-07-25
AU2009317877B2 (en) 2014-10-23
EP2366120A1 (fr) 2011-09-21
AU2009317877A1 (en) 2010-05-27
US20120161931A1 (en) 2012-06-28
US9164169B2 (en) 2015-10-20

Similar Documents

Publication Publication Date Title
AU2009317877B2 (en) Radio frequency transponder system
Islam et al. Compact printable chipless RFID systems
Karmaker Tag, you're it radar cross section of chipless RFID tags
Islam et al. A $4\times 4$ Dual Polarized mm-Wave ACMPA Array for a Universal mm-Wave Chipless RFID Tag Reader
Uddin et al. UHF RFID antenna architectures and applications
Babaeian et al. A high gain dual polarized ultra-wideband array of antenna for chipless RFID applications
Islam et al. ‘Δ’slotted compact printable orientation insensitive chipless RFID tag for long range applications
Abbak et al. RFID coverage extension using microstrip-patch antenna array [wireless corner]
Ali et al. Millimeter-wave substrate integrated waveguide passive Van Atta reflector array
Re et al. FMCW radar with enhanced resolution and processing time by beam switching
Mekki et al. Investigation on the chipless RFID tag with a UWB pulse using a UWB IR-based reader
Koswatta et al. Investigation into antenna performance on read range improvement of chipless RFID tag reader
Islam et al. An 8× 8 mm-wave LP ACMPA array for a long-range mm-wave chipless RFID tag-sensor reader
Zomorrodi et al. Introduction of electromagnetic image-based chipless RFID system
Wang et al. A wide-angle and fully polarimetric retrodirective array based on tri-polarized antennas with pattern complementation
Son et al. Design of a circularly polarised radio-frequency identification reader antenna with high return loss
Lee et al. Wide-coverage array antenna using a dual-beam switching for UHF RFID applications
Balbin et al. Multi-antenna backscattered chipless RFID design
Lee et al. Quadruple‐feed beam‐controlled antenna array for the localisations of ultra‐high‐frequency radio‐frequency identification tags
Patel et al. Passive RFID tags for metallic environments using phased array reader antennas
Babaeian et al. 4× 4 element UWB dual-polarized aperture coupled microstrip patch antenna array for chipless RFID
Numan et al. Wide field of view retrodirective millimeter wave antenna array with pulse modulation and orthogonal polarization states
Lin et al. Broadband and high-gain antenna for frequency-coded chipless RFID handheld readers
Nataraj et al. Design of an Antenna Array for Radar Application
Di Carlofelice et al. Exploring Van-Atta UWB cross-pol chipless tag

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 200980155302.3

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09827052

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2009317877

Country of ref document: AU

WWE Wipo information: entry into national phase

Ref document number: 2743955

Country of ref document: CA

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2009317877

Country of ref document: AU

Date of ref document: 20091120

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 2009827052

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 593545

Country of ref document: NZ

WWE Wipo information: entry into national phase

Ref document number: 4724/DELNP/2011

Country of ref document: IN