RFID ANTENNA, RFID TAG AND METHOD FOR MANUFACTURING SUCH AN ANTENNA RFID

Abstract

RFID ANTENNA, RFID TAG AND METHOD FOR MANUFACTURING SUCH AN RFID ANTENNA The present invention relates to an RFID antenna (28) comprising: - a central inductive circuit (50), and - at least two lobes (52) extending radially from the central inductive circuit (50). Figure: Figure 2

Description

Title of the invention: RFID ANTENNA, RFID TAG AND METHOD FOR MANUFACTURING SUCH AN RFID ANTENNA TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to an RFID antenna. The present invention also relates to an RIFD tag comprising such an RFID antenna and a method of manufacturing this RFID tag.

[0002] CONTEXT OF THE INVENTION

[0003] Radio Frequency Identification (RFID) has become a very important identification and tracking tool for packaged goods, after barcodes and text. To achieve these operations, RFID technology uses electromagnetic fields to automatically identify and track RFID tags attached to objects.

[0004] These RFID tags have enabled the rapid deployment of wireless automatic identification of products, parts, supplies, equipment, and animals. The RFID tags are attached to or incorporated into the items or their packaging and programmed with variable identification information specific to the item. The RFID tags can be incorporated into the packages either by affixing an embedded RFID tag or by affixing an RFID tag to the package.

[0005] However, in practice, the detection of RFID tags is not satisfactory, because the reading range is very short. Summary of the invention

[0006] It is therefore necessary to have an RIFD antenna with a greater reading range.

[0007] To this end, the specification describes an RFID antenna comprising:

[0008] - a central inductive circuit, and

[0009] - at least two lobes extending radially from the central inductive circuit.

[0010] According to other aspects of the RFID antenna, which are advantageous but not mandatory, the RFID antenna may incorporate one or more of the following features, taken in any technically permissible combination:

[0011] - each lobe belongs to a respective pair of lobes, two lobes of the same pair of lobes being symmetrical with respect to the central inductive circuit.

[0012] - the at least two lobes comprise primary lobes and at least one lobe lateral, the angle between the lateral lobe and one of the primary lobes being less than 90°.

[0013] - the angle between the side lobe and one of the primary lobes is less than 60°.

[0014] - a width and a length are defined for each lobe, the width of each side lobe being less than the smallest width of the primary lobes and the length of each side lobe being less than the smallest length of the primary lobes.

[0015] - the surface area of ​​the central inductive circuit is less than 300 mm2.

[0016] - the central inductive circuit extends between an internal periphery and the periphery external, the ratio between the surface area of ​​the central inductive circuit and the surface area of ​​the internal periphery being between 0.18 and 2.75.

[0017] - an aspect ratio is defined for each lobe, the aspect ratio of each lobe being between 0.25 and 2.00.

[0018] - the aspect ratio of each lobe is less than 1.00.

[0019] - a minimum width is defined for each lobe, the minimum width of each lobe being greater than 0.1 mm.

[0020] - the central inductive circuit extends from an internal periphery to an external periphery for which respective diameters are defined, the diameter of the internal periphery being between 8.0 mm and 20.0 mm.

[0021] - the difference between the diameters of the inner periphery and the outer periphery is greater than 5.0 mm.

[0022] - the lobes and the central inductive circuit are made of the same conductive material.

[0023] - a length is defined for the antenna, the length of the antenna being greater than 40 mm.

[0024] - the length of the antenna is between 80 mm and 100 mm.

[0025] - the RFID antenna is adapted to receive and transmit signals to frequencies belonging to a frequency range extending from 860 MHz to 960 MHz.

[0026] - the number of lobes is even.

[0027] - the number of lobes is between 2 and 10.

[0028] - the lobes are placed symmetrically around the central inductive circuit.

[0029] - the length of the antenna is greater than 50 mm, preferably greater than 80 mm and, more preferably, greater than or equal to 100 mm.

[0030] - the length of the antenna is between 80 mm and 100 mm.

[0031] - the length of the antenna is equal to 80 mm with a margin of 10%, preferably of 5%, advantageously of 2% and more preferably of 1%. A quantity A is equal to B with a margin of X% when the quantity is between (1-X%)*B and (1+X%)*B.

[0032] - the length of the antenna is equal to 100 mm with a margin of 10%, preferably of 5%, advantageously of 2% and more preferably of 1%.

[0033] - a maximum width is defined for a lobe as the maximum dimension the along an axis orthogonal to the axis of symmetry of the lobe.

[0034] - the maximum width of the lobe is between 10 mm and 50 mm.

[0035] - the maximum width of the lobe is equal to 10 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0036] - the maximum width of the lobe is equal to 15 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0037] - the maximum width of the lobe is equal to 20 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0038] - the maximum width of the lobe is equal to 30 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0039] - the maximum width of the lobe is equal to 50 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0040] - a length is defined for the lobe as the maximum distance between the pro orthogonal projections of two points of the lobe on an axis of symmetry of the lobe.

[0041] - the length of the lobe is between 20 mm and 60 mm.

[0042] - the length of the lobe is equal to 20 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0043] - the length of the lobe is equal to 25 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0044] - the length of the lobe is equal to 30 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0045] - the length of the lobe is equal to 35 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0046] - the length of the lobe is equal to 40 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0047] - the length of the lobe is equal to 45 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0048] - the length of the lobe is equal to 50 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0049] - the length of the lobe is equal to 60 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0050] - an internal diameter is defined for the central inductive circuit as the diameter of the inner periphery of the central inductive circuit.

[0051] - the internal diameter of the central inductive circuit 28 is between 7 mm and 30 mm.

[0052] - the internal diameter of the central inductive circuit is equal to 7 mm with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0053] - the internal diameter of the central inductive circuit is equal to 7.5 mm with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0054] - the internal diameter of the central inductive circuit is equal to 8 mm with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0055] - the internal diameter of the central inductive circuit is equal to 8.5 mm with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0056] - the internal diameter of the central inductive circuit is equal to 9 mm with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0057] - the internal diameter of the central inductive circuit is equal to 9.5 mm with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0058] - the internal diameter of the central inductive circuit is equal to 10 mm with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0059] - the internal diameter of the central inductive circuit is equal to 12 mm with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0060] - the internal diameter of the central inductive circuit is equal to 15 mm with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0061] - the internal diameter of the central inductive circuit is equal to 16 mm with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0062] - the internal diameter of the central inductive circuit is equal to 17 mm with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0063] - the internal diameter of the central inductive circuit is equal to 18 mm with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0064] - the internal diameter of the central inductive circuit is equal to 19 mm with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0065] - the internal diameter of the central inductive circuit is equal to 20 mm with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0066] - the internal diameter of the central inductive circuit is equal to 25 mm with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% or more preferably a margin of 1%.

[0067] - the internal diameter of the central inductive circuit is equal to 30 mm with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0068] - an external diameter is defined for the central inductive circuit as the diameter of the outer periphery of the central inductive circuit.

[0069] - the external diameter of the central inductive circuit is between 8 mm and 40 mm.

[0070] - the external diameter of the central inductive circuit is equal to 8.8 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0071] - the external diameter of the central inductive circuit is equal to 10 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0072] - the external diameter of the central inductive circuit is equal to 11 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0073] - the external diameter of the central inductive circuit is equal to 12 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0074] - the external diameter of the central inductive circuit is equal to 14 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0075] - the external diameter of the central inductive circuit is equal to 15 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0076] - the external diameter of the central inductive circuit is equal to 18 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0077] - the external diameter of the central inductive circuit is equal to 20 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0078] - the external diameter of the central inductive circuit is equal to 25 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0079] - the external diameter of the central inductive circuit is equal to 26 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0080] - the external diameter of the central inductive circuit is equal to 27 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0081] - the external diameter of the central inductive circuit is equal to 28 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0082] - the external diameter of the central inductive circuit is equal to 29 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0083] - the external diameter of the central inductive circuit is equal to 35 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0084] - the external diameter of the central inductive circuit is equal to 40 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0085] - the width of the central inductive circuit is between 8.0 and 20.0.

[0086] - the width of the central inductive circuit is equal to 8.0 mm with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0087] - the width of the central inductive circuit is equal to 9 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0088] - the width of the central inductive circuit is equal to 10 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0089] - the width of the central inductive circuit is equal to 11 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0090] - the width of the central inductive circuit is equal to 12 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0091] - the width of the central inductive circuit is equal to 13 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0092] - the width of the central inductive circuit is equal to 14 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0093] - the width of the central inductive circuit is equal to 15 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0094] - the width of the central inductive circuit is equal to 16 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0095] - the width of the central inductive circuit is equal to 17 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0096] - the width of the central inductive circuit is equal to 18 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0097] - the width of the central inductive circuit is equal to 19 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0098] - the width of the central inductive circuit is equal to 20.0 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0099] - a main axis and a secondary axis are defined for the central inductive circuit.

[0100] - the main axis of the central inductive circuit is between 4.0 mm and 25.0 mm.

[0101] - the main axis of the central inductive circuit is equal to 4.4 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0102] - the main axis of the central inductive circuit is equal to 5 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0103] - the main axis of the central inductive circuit is equal to 6 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0104] - the main axis of the central inductive circuit is equal to 7 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0105] - the main axis of the central inductive circuit is equal to 9 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0106] - the main axis of the central inductive circuit is equal to 10 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0107] - the main axis of the central inductive circuit is equal to 12 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0108] - the main axis of the central inductive circuit is equal to 13 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0109] - the main axis of the central inductive circuit is equal to 14 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0110] - the main axis of the central inductive circuit is equal to 20.0 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0111] - the minor axis of the central inductive circuit is between 3.0 mm and 15.0 mm.

[0112] - the minor axis of the central inductive circuit is equal to 3.5 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0113] - the minor axis of the central inductive circuit is equal to 4.0 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0114] - the minor axis of the central inductive circuit is equal to 4.5 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0115] - the minor axis of the central inductive circuit is equal to 5.0 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0116] - the minor axis of the central inductive circuit is equal to 7.5 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0117] - the minor axis of the central inductive circuit is equal to 8.0 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0118] - the minor axis of the central inductive circuit is equal to 9.0 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0119] - the minor axis of the central inductive circuit is equal to 10.0 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0120] - the minor axis of the central inductive circuit is equal to 12.5 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0121] - the lobe comprising a proximal segment, the length of the proximal segment is the minimum lobe width.

[0122] - the minimum width of the lobe is between 0.4 mm and 10 mm.

[0123] - the minimum lobe width is equal to 0.4 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0124] - the minimum lobe width is equal to 0.5 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0125] - the minimum lobe width is equal to 1 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0126] - the minimum lobe width is equal to 1.5 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0127] - the minimum width of the lobe is equal to 2 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0128] - the minimum lobe width is equal to 2.5 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0129] - the minimum width of the lobe is equal to 3 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0130] - the minimum lobe width is equal to 4 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0131] - the minimum width of the lobe is equal to 5 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0132] - the minimum lobe width is equal to 7.5 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0133] - the minimum width of the lobe is equal to 10 mm with a margin of 10%, preferably 5%, advantageously 2% and more preferably 1%.

[0134] - the surface area of ​​the central inductive circuit is between 5.0 mm2 and 475 mm2.

[0135] - the surface area of ​​the central inductive circuit is equal to 5.3 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0136] - the surface area of ​​the central inductive circuit is equal to 14.1 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0137] - the surface area of ​​the central inductive circuit is equal to 17.5 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0138] - the surface area of ​​the central inductive circuit is equal to 18.25 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0139] - the surface area of ​​the central inductive circuit is equal to 20.0 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0140] - the surface area of ​​the central inductive circuit is equal to 22.8 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0141] - the surface area of ​​the central inductive circuit is equal to 23.6 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0142] - the surface area of ​​the central inductive circuit is equal to 28.3 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0143] - the surface area of ​​the central inductive circuit is equal to 29.8 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0144] - the surface area of ​​the central inductive circuit is equal to 31.4 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0145] - the surface area of ​​the central inductive circuit is equal to 34.7 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0146] - the surface area of ​​the central inductive circuit is equal to 37.3 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0147] - the surface area of ​​the central inductive circuit is equal to 48.8 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0148] - the surface area of ​​the central inductive circuit is equal to 50.2 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably- initially a margin of 1%.

[0149] - the surface area of ​​the central inductive circuit is equal to 51.2 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0150] - the surface area of ​​the central inductive circuit is equal to 51.8 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0151] - the surface area of ​​the central inductive circuit is equal to 54.2 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0152] - the surface area of ​​the central inductive circuit is equal to 55.7 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0153] - the surface area of ​​the central inductive circuit is equal to 57.3 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0154] - the surface area of ​​the central inductive circuit is equal to 60.6 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0155] - the surface area of ​​the central inductive circuit is equal to 61.2 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0156] - the surface area of ​​the central inductive circuit is equal to 63.2 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0157] - the surface area of ​​the central inductive circuit is equal to 67.5 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0158] - the surface area of ​​the central inductive circuit is equal to 70.7 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0159] - the surface area of ​​the central inductive circuit is equal to 87.9 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0160] - the surface area of ​​the central inductive circuit is equal to 102.1 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0161] - the surface area of ​​the central inductive circuit is equal to 157.0 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0162] - the surface area of ​​the central inductive circuit is equal to 168.8 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0163] - the surface area of ​​the central inductive circuit is equal to 180.6 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0164] - the surface area of ​​the central inductive circuit is equal to 184.5 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0165] - the surface area of ​​the central inductive circuit is equal to 200.0 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0166] - the surface area of ​​the central inductive circuit is equal to 226.0 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0167] - the surface area of ​​the central inductive circuit is equal to 304.2 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0168] - the surface area of ​​the central inductive circuit is equal to 471.0 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0169] - the area of ​​the surface delimited by the internal periphery is between 19.0 mm2 and 250.0 mm2.

[0170] - the area of ​​the surface delimited by the internal periphery is equal to 19.2 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0171] - the area of ​​the surface delimited by the internal periphery is equal to 21.7 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0172] - the area of ​​the surface delimited by the internal periphery is equal to 25.1 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0173] - the area of ​​the surface delimited by the internal periphery is equal to 26.7 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0174] - the area of ​​the surface delimited by the internal periphery is equal to 28.3 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0175] - the area of ​​the surface delimited by the internal periphery is equal to 33.6 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0176] - the area of ​​the surface delimited by the internal periphery is equal to 39.3 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0177] - the area of ​​the surface delimited by the internal periphery is equal to 47.1 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0178] - the area of ​​the surface delimited by the internal periphery is equal to 50.2 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0179] - the area of ​​the surface delimited by the internal periphery is equal to 53.3 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0180] - the area of ​​the surface delimited by the internal periphery is equal to 56.5 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0181] - the area of ​​the surface delimited by the internal periphery is equal to 59.6 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0182] - the area of ​​the surface delimited by the internal periphery is equal to 88.3 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0183] - the area of ​​the surface delimited by the internal periphery is equal to 94.2 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0184] - the area of ​​the surface delimited by the internal periphery is equal to 100.5 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0185] - the area of ​​the surface delimited by the internal periphery is equal to 106.7 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0186] - the area of ​​the surface delimited by the internal periphery is equal to 127.2 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0187] - the area of ​​the surface delimited by the internal periphery is equal to 134.2 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0188] - the area of ​​the surface delimited by the internal periphery is equal to 157.0 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0189] - the area of ​​the surface delimited by the internal periphery is equal to 245.3 mm2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0190] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the inner periphery is between 0.2 and 4.2.

[0191] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 0.2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0192] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 0.5 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0193] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 0.6 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0194] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 0.8 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0195] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 0.9 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0196] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 1.0 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0197] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 1.1 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0198] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 1.2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0199] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 1.3 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0200] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 1.4 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0201] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 1.5 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0202] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 1.6 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0203] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 1.7 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0204] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 1.9 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0205] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 2.1 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0206] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 2.2 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0207] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 2.3 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0208] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 2.8 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0209] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 3.0 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0210] - the ratio between the area of ​​the central inductive circuit and the area of ​​the surface delimited by the internal periphery is equal to 4.1 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0211] - the aspect ratio of a lobe is the ratio between the maximum width of the lobe and the lobe length.

[0212] - the aspect ratio of the lobe is between 0.25 and 2.00.

[0213] - the aspect ratio of the lobe is between 0.25 and 1.00.

[0214] - the aspect ratio of the lobe is between 0.25 and 2.00.

[0215] - the aspect ratio of the lobe is between 0.25 and 0.80.

[0216] - the aspect ratio of the lobe is between 0.25 and 0.50.

[0217] - the aspect ratio of the lobe is between 0.30 and 0.50.

[0218] - the aspect ratio of the lobe is between 0.30 and 0.40.

[0219] - the aspect ratio of the lobe is equal to 0.27 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0220] - the aspect ratio of the lobe is equal to 0.33 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0221] - the aspect ratio of the lobe is equal to 0.34 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0222] - the aspect ratio of the lobe is equal to 0.35 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0223] - the aspect ratio of the lobe is equal to 0.36 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a 1% margin.

[0224] - the aspect ratio of the lobe is equal to 0.37 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0225] - the aspect ratio of the lobe is equal to 0.38 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0226] - the aspect ratio of the lobe is equal to 0.40 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0227] - the aspect ratio of the lobe is equal to 0.41 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0228] - the aspect ratio of the lobe is equal to 0.42 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0229] - the aspect ratio of the lobe is equal to 0.46 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0230] - the aspect ratio of the lobe is equal to 0.50 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0231] - the aspect ratio of the lobe is equal to 0.53 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0232] - the aspect ratio of the lobe is equal to 0.80 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0233] - the aspect ratio of the lobe is equal to 1.02 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0234] - the aspect ratio of the lobe is equal to 1.09 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0235] - the aspect ratio of the lobe is equal to 1.33 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0236] - the aspect ratio of the lobe is equal to 1.82 with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0237] - the inter-lobe angle is between 25° and 70°, preferably between 30° and 60°.

[0238] - the inter-lobe angle is equal to 30° with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0239] - the inter-lobe angle is equal to 35° with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0240] - the inter-lobe angle is equal to 45° with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0241] - the inter-lobe angle is equal to 60° with a margin of 10%, preferably a margin of 5%, advantageously a margin of 2% and more preferably a margin of 1%.

[0242] The specification also relates to an RFID tag comprising an RFID antenna as described above, and an RFID chip in which said RFID chip is electrically connected to the central inductive circuit of said RFID antenna.

[0243] The specification also relates to a method of manufacturing an RFID tag, the manufacturing method comprising a step of forming an RFID antenna on a substrate, the RFID antenna comprising:

[0244] - a central inductive circuit, and

[0245] - at least two lobes extending radially from the central inductive circuit,

[0246] the forming step is carried out using a method selected from conductive metal transfer printing, conductive inkjet printing and conductive screen printing.

[0247] According to other aspects of the method, which are advantageous but not mandatory, the manufacturing method may comprise one or more of the following features, taken in any technically permissible combination:

[0248] - the manufacturing process comprises:

[0249] - cutting an RFID antenna from a sheet of metal, the RFID antenna including:

[0250] - a central inductive circuit, and

[0251] - at least two lobes extending radially from the central inductive circuit, and

[0252] - fix the RFID antenna to the substrate by gluing.

[0253] - the manufacturing process comprises:

[0254] - a step of providing a metallized substrate with a continuous layer of metal,

[0255] - a step of forming an RFID antenna comprising:

[0256] - a central inductive circuit, and

[0257] - at least two lobes extending radially from the central inductive circuit,

[0258] the forming step is performed by removing metal from the substrate outside the areas dedicated to forming the RFID antenna using a chemical technique or mechanical etching. Brief description of the drawings

[0259] The invention will be better understood on the basis of the following description which is given in correspondence with the appended figures and by way of illustrative example, without restricting the subject of the invention. In the appended figures:

[0260] - [Fig.l] is a schematic representation of an RFID system comprising a RFID antenna,

[0261] - [Fig.2] is a schematic representation of an example of an RFID antenna seen from above and offering an improved reading range, the RFID antenna comprising a central inductive circuit and lobes,

[0262] - [Fig.3] is a schematic representation of another example of an RFID antenna top view with another shape for the central inductive circuit,

[0263] - [Fig.4] is a schematic representation of several examples of antennas RFID top views with other shapes for the central inductive circuit,

[0264] - [Fig.5] is a schematic representation of the different layers of a label,

[0265] - [Fig.6] is a schematic representation of an example of an RFID antenna provided of a chip,

[0266] - [Fig.7] is a schematic representation of another example of an RFID antenna top view,

[0267] - [Fig.8] is a schematic representation of 15 other examples of antennas RFID top views,

[0268] - [Fig.9] is a schematic representation of twelve examples of RFID antennas according to the prior art.

[0269] - [Fig. 10] is a schematic representation of a custom probe, and

[0270] - [Fig.l 1] is a schematic representation of the field of an RFID reader.

[0271] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0272] An RFID system 10 is illustrated in [Fig.l].

[0273] The RFID system 10 comprises an RFID reader 12, a controller 14 and an RFID tag 16.

[0274] In this RFID system 10, the RFID reader 12 and the controller 14 can be considered active to the extent that they are supplied with electricity.

[0275] On the other hand, the RFID tag 16 is passive.

[0276] The RFID reader 12 is the main power source for the RFID system 10.

[0277] The RFID reader 12 interacts with the controller 14 to read / write and send in RFID tag order training 16.

[0278] For example, the controller 14 is here a smartphone system using an Android / iOS application to control the operation of the RFID reader 12.

[0279] In the example of [Fig.l], the RFID reader 12 comprises a signal generator 18, a transmitting antenna 20, a receiving antenna 22, an amplifier 24 and a processing unit 26.

[0280] The RFID tag 16 comprises an RFID antenna 28, a power supply unit 30, a memory 32 and a logic unit 34.

[0281] In operation, the signal generator 18 generates a UHF signal 36, which is transmitted by the antenna 20 to the RFID tag 16.

[0282] A UHF signal is a signal belonging to the UHF band, that is to say a signal whose frequency is between 860 MHz and 960 MHz.

[0283] Using such a frequency range significantly increases the distance at which the tagged object can be identified by RFID.

[0284] Each antenna disclosed in the present specification is therefore preferably designed to operate at frequencies belonging to a frequency range extending from 860 MHz to 960 MHz.

[0285] This implies that each antenna has specific dimensions to generate or detect signals at that frequency.

[0286] The UHF signal 36 transmitted by the RFID reader 12 includes a control signal which can be used to request data from the RFID tag 16.

[0287] The UHF signal 36 is picked up by the RFID antenna 28, which provides power to the power supply unit 30 to power the RFID tag 16.

[0288] The memory 32 includes data, such as the tag identification data.

[0289] The RFID tag 16, powered by the UHF signal 36, interprets this signal with the logic unit 34 and, if the logic unit 34 deems it appropriate, responds with a response signal 38.

[0290] In other words, the RFID tag 16 then uses the energy stored in the power supply unit 30 to respond with the requested data by taking the same path to the RFID reader 12, and the signal sent by the RFID tag 16 to the RFID reader 12 is called a backscatter signal. The backscatter signal responds with the requested data on the same signal.

[0291] The response signal 38 is therefore called the backscatter signal.

[0292] The response signal 38 includes the identification data of the tag.

[0293] The response signal 38 is received by the receiving antenna 22.

[0294] The received signal is amplified by amplifier 24.

[0295] The processing unit 26 interprets the amplified signal and sends the information to the controller 14 for use.

[0296] As is apparent from this operation, the backscatter signal 38 constitutes the backbone of this RFID system 10 and allows the passive RFID tag 16 to respond to an identification request from a reader 12.

[0297] This operation assumes that the RFID tag 16 can communicate with the antennas 20 and 22 of the RFID reader 12.

[0298] For this, the RFID tag 16 must be close to the RFID reader 12.

[0299] In other words, this means that the reading distance 40 must be as short as possible.

[0300] The reading distance 40 corresponds to the distance between the transmitting antenna 20 and the RFID antenna 28.

[0301] This distance is set by the electromagnetic field produced by the RFID antenna 28. More precisely, the reading distance 40 must be included in the reading range RR. The reading range RR includes the entire possible reading distance and corresponds to the distances at which the electromagnetic field produced by the RFID antenna 28 can be read by an RFID reader.

[0302] In order to improve reading, it is therefore desirable that the RFID antenna 28 can generate an electromagnetic field offering a better reading range RR.

[0303] An example design of an RFID antenna 28 having such an advantage is shown in [Fig.2].

[0304] The RFID antenna 28 extends mainly in a plane perpendicular to the direction of propagation of the UHF signal 36 and the response signal 38.

[0305] This propagation direction corresponds to a Z axis in [Fig.2], so that the propagation direction is hereinafter called the Z propagation direction.

[0306] Two transverse directions are also defined, a first transverse direction corresponding to an X axis (which is horizontal in the plane of [Fig.2]) and a second transverse direction corresponding to a Y axis (which is vertical in the plane of [Fig.2]).

[0307] Hereinafter, these transverse directions are respectively called first transverse direction X and second transverse direction Y.

[0308] The RFID antenna 28 comprises a central inductive circuit 50 (hereinafter referred to as central circuit 50) and two lobes 52.

[0309] This example is not limiting insofar as other embodiments are envisaged, in particular with reference to figures 3, 4, 6, 7 or 8.

[0310] The central circuit 50 is a conductive track which extends between two ends 54, the two ends 54 being separated in space.

[0311] The central circuit 50 is, for example, made of a conductive metal, such as copper, aluminum, silver, gold, etc.

[0312] In the present example, the small space 56 between the ends 54 gives a substantially annular shape to the central circuit 50.

[0313] This means that the central circuit 50 is comprised between an internal periphery 58 and an external periphery 60.

[0314] The inner periphery 58 and the outer periphery 60 are, in the present example, concentric circles.

[0315] An inner diameter D58 and an outer diameter D60 can be defined as being respectively the diameter of the inner periphery 58 and the diameter of the outer periphery 60.

[0316] The internal diameter D58 is between 8 mm (millimeters) and 30 mm.

[0317] The width W50 of the central circuit 50 is defined as the difference between the external diameter D60 and the internal diameter D58.

[0318] The width W50 of the central circuit 50 is greater than 5 mm, preferably less than 10 mm.

[0319] The surface A50 of the central circuit 50 is defined as the result of the surface A60 of the external periphery 60 minus the surface A58 of the internal periphery 58.

[0320] The surface A50 of the central circuit 50 is less than 300 mm2.

[0321] Preferably, the surface A50 of the central circuit 50 is greater than 50 mm2, preferably greater than 100 mm2.

[0322] A first ratio RI can also be defined as being the ratio between the surface A50 of the central circuit 50 and the surface A58 of the internal periphery 58.

[0323] The first ratio RI is preferably between 0.18 and 2.75.

[0324] Other geometries can be envisaged for the central circuit 50.

[0325] In particular, it can be considered as an oval shape, as shown schematically in [Fig.3].

[0326] In this case, the inner periphery 58 becomes an inner ellipse and the outer periphery 60 becomes an outer ellipse.

[0327] The equivalent of the diameter is the combination of two distances: the major axis M58 (respectively M60) and a minor axis m58 (respectively m60).

[0328] In the representation of [Fig.3], the main axis M58 (respectively M60) extends along the first transverse direction X while the secondary axis m58 (respectively m60) extends along the second transverse direction Y.

[0329] Other shapes corresponding to the oval shape of the central circuit 50 are shown in drawings A to C of [Fig.4].

[0330] In these figures, drawing A is an elongated oval shape corresponding to the shape of a horseshoe, while designs B to C are oval shapes with a larger gap between the ends.

[0331] It can also be considered as a rectangular shape, as shown schematically in drawing D of [Fig.4].

[0332] In this case, the inner periphery 58 becomes an inner rectangle and the outer periphery 60 becomes an outer rectangle.

[0333] The equivalent of the diameter is the combination of two distances: the length L58 (respectively L60) and the width W58 (respectively W60) of the internal periphery 58 (respectively of the external periphery 60).

[0334] In the representation of [Fig.2], the length L58 (respectively L60) extends along the first transverse direction X while the width W58 (respectively W60) extends along the second transverse direction Y.

[0335] More generally, it appears that the shape of the central circuit 50 is such that the central circuit 50 corresponds to a track with a space between two ends and extending between an internal shape and an external shape.

[0336] Preferably, the inner shape and the outer shape are identical and share the same center.

[0337] Further, the shape is such that the width of the central circuit 50 is the same in each direction.

[0338] If we return to [Fig.2], the ends 54 have a non-limiting square shape and are separated in space by a rectangular space.

[0339] The two lobes 52 constitute a circuit made of conductive material, generally the same as that used for the central circuit 50.

[0340] The lobe 52 comprises a proximal portion 52P and a distal portion 52D.

[0341] An element is a lobe when the proximal portion forms a truncated divergent element closed at one end by the distal portion, the distal portion being delimited by a circle.

[0342] This gives the lobe the shape of a flower petal, more precisely a daisy petal.

[0343] In the present case, the lobe is truncated because each lobe 52 extends from the outer periphery 60 of the central circuit 50.

[0344] This implies that each lobe 52 extends between four edges, an extreme edge 62, a first proximal edge 64, a second proximal edge 66 and a distal edge 68.

[0345] The extreme edge 62 and the distal edge 68 are a portion of a circle.

[0346] The extreme edge 62 is here concave while the distal edge 68 is convex.

[0347] In the present case, the first proximal edge 64 and the second proximal edge 66 are lines.

[0348] Furthermore, each lobe 52 extends along an axis of symmetry 70.

[0349] The axis of symmetry 70 is a radial direction relative to the central circuit 50.

[0350] This implies that the first proximal edge 64 and the second proximal edge 66 are symmetrical about the 70 axis of symmetry.

[0351] The axis of symmetry 70 separates the distal edge 68 into two equal parts.

[0352] Further, the first proximal edge 64, the second proximal edge 66 and the distal edge 68 form a continuous curve.

[0353] This means that at each point on the curve formed by these edges 64, 66 and 68, the tangent to the curve is continuous. In other words, the tangent at each point on the curve has the same value on the left and on the right.

[0354] In particular, there is no point where the tangent abruptly changes value, as in the case of an acute angle.

[0355] The edges 62, 64, 66 and 68 make it possible to define specific points for each lobe 52.

[0356] These specific points are as follows: • a first proximal end 72, which is the intersection between the external periphery 60 of the central circuit 50 and the first proximal edge 64, • a second proximal end 74, which is the intersection between the external periphery 60 of the central circuit 50 and the second proximal edge 66, • a first intermediate point 76, which is the intersection between the first proximal edge 64 and the distal edge 68, • a second intermediate point 78, which is the intersection between the second proximal edge 66 and the distal edge 68, and • a distal end 80, which is the middle of the distal edge 68 or the intersection between the distal edge 68 and the axis of symmetry 70.

[0357] A vertex 82 is also defined for each lobe 52, the vertex 82 being defined as the intersection of the first proximal edge 64 and the second proximal edge 66.

[0358] The lobe being truncated in the case of [Fig.2], the apex 82 is represented by extending the first proximal edge 64 and the second proximal edge 66 by dotted lines.

[0359] This representation makes it possible to define a divergence angle 84 for the lobe 52, the divergence angle 84 being the angle formed at the vertex 82 between the first proximal edge 64 and the second proximal edge 66.

[0360] The divergence angle 84 is between 0° and 25°, preferably between 5° and 10°.

[0361] It is also noted that the apex 82 and the distal end 80 are aligned along the axis of symmetry 70.

[0362] Based on these specific points, it is also possible to define characteristic dimensions for the lobe 52, namely the length L52 of the lobe 52, the maximum width MW52 of the lobe 52 and the minimum width W52.

[0363] The length L52 is the extension of the lobe 52 along the axis of symmetry 70, namely the maximum distance between the orthogonal projections of two points of the lobe 52 on the axis of symmetry 70.

[0364] Length L52 is the distance between distal end 80 and a proximal segment 86, proximal segment 86 connecting first proximal end 72 and second proximal end 74.

[0365] The length L52 is between 25 mm and 50 mm.

[0366] The maximum width MW52 is the extension of the lobe 52 along an orthogonal axis perpendicular to the axis of symmetry 70.

[0367] This orthogonal axis is here parallel to the second transverse direction Y.

[0368] The maximum width MW52 is the maximum distance between the orthogonal projections of two points of the lobe 52 on the orthogonal axis 88.

[0369] In the present case, the maximum width MW52 is the distance between the first intermediate point 76 and the second intermediate point 78. The maximum width MW52 is the length of an intermediate segment 90, the intermediate segment 90 connecting the first intermediate point 76 and the second intermediate point 78.

[0370] The maximum width MW52 is between 10 mm and 50 mm.

[0371] In the present example, the ratio AR between the maximum width MW52 of the lobe 52 and the length L52 of the lobe 52 is less than 2, preferably less than 1 and more preferably less than 0.8.

[0372] The ratio AR between the maximum width MW52 of the lobe 52 and the length L52 of the lobe 52 is noted AR because this ratio corresponds to the aspect ratio of the lobe 52.

[0373] Hereinafter, this value is called the aspect ratio AR of lobe 52.

[0374] The aspect ratio AR is greater than 0.25.

[0375] The minimum width W52 corresponds to the length of the proximal segment 86.

[0376] In the present example, the proximal segment 86 and the intermediate segment 90 are both parallel to the second transverse direction Y.

[0377] The proximal portion 52P therefore diverges from the minimum width W52 to the maximum width MW52 when following the proximal portion 52P from the proximal segment 86 to the intermediate segment 90.

[0378] The minimum width W52 is greater than 0.1 mm, preferably greater than 0.5 mm.

[0379] In the example of [Fig.2], the distal edge 68 is a semicircle.

[0380] The diameter of the distal edge 68, which corresponds to the diameter of this semicircle, is hereinafter called D68.

[0381] The diameter D68 of the distal edge 68 is between 5 mm and 45 mm, preferably between 10 mm and 30 mm.

[0382] In the case of [Fig.2], the two lobes 52 have the same shape here.

[0383] Furthermore, the lobes 52 constitute a pair.

[0384] In the present description, two lobes 52 form a pair when their axes of symmetry 70 are aligned (along the first transverse direction X of [Fig.2]).

[0385] This implies that the RFID antenna 28 is symmetrical with respect to the second transverse direction Y.

[0386] Furthermore, the RFID antenna 28 of the embodiment of [Fig.2] is also symmetrical with respect to the first transverse direction X.

[0387] The length L28 of the RFID antenna 28 is defined as the greatest distance between two points of the RFID antenna 28 along the main direction.

[0388] In the present case, the length of the RFID antenna 28 is the sum of the length of the central circuit 50 and twice the length of the lobes 52.

[0389] The length L28 of the RFID antenna 28 is greater than 40 mm.

[0390] Preferably, the length L28 of the RFID antenna 28 is between 80 mm and 120 mm.

[0391] Alternatively or additionally, the length L28 of the RFID antenna 28 is a fraction of the UHF wavelength of the UHF signal 36.

[0392] Preferably, the fraction is equal to % with a margin of 1% (which gives a length between 80 mm and 100 mm) or to U2 with the same margin (which gives a length between 160 mm and 200 mm).

[0393] This RFID antenna 28 is part of an RFID tag, as can be seen in [Fig.5],

[0394] More precisely, it is the RFID antenna 28 provided with an RFID chip 100, as visible in [Fig.6], which constitutes a layer of the RFID tag of [Fig.5]

[0395] The RFID chip 100 is here a chip or a Higg band, which is attached to the ends 54.

[0396] This RFID antenna 28 is intended to be integrated into an RFID tag.

[0397] An example of the different layers 28, 100, 102, 104, 106 and 108 of such an RFID tag 110 is shown schematically in [Fig.5].

[0398] Above the RFID antenna 28 are the RFID chip 100, the face (layer 102) and the shell (layer 104), if applicable.

[0399] Under the RFID antenna 28, there is the substrate (layer 106) and the adhesive (layer 108), if applicable.

[0400] The layers of the RFID tag 110 will in practice depend on the method of manufacturing the RFID antenna 28.

[0401] The RFID tag can be manufactured using several techniques, easily accessible to those skilled in the art.

[0402] According to a first example of techniques, the method of manufacturing the antenna RFID 28 includes a step of forming the RFID antenna 28 using conductive metal transfer printing.

[0403] According to a second example technique, the method of manufacturing the RFID antenna 28 comprises a step of forming the RFID antenna 28 using conductive inkjet printing.

[0404] According to a third example technique, the method of manufacturing the RFID antenna 28 comprises a step of forming the RFID antenna 28 using conductive screen printing.

[0405] According to a fourth example technique, the method of manufacturing the antenna comprises a step of cutting the RFID antenna 28 from a metal sheet and a step of adhesively fixing the antenna to the substrate.

[0406] According to the fifth technique example, the method of manufacturing the RFID antenna 28 comprises a step of providing a metallized substrate with a continuous layer of metal and a step of forming the antenna by removing the metal from the substrate outside the areas dedicated to the formation of the RFID antenna 28.

[0407] This removal can be carried out by a chemical technique or by mechanical etching.

[0408] Based on this manufacturing method, an RFID tag can be produced, for example, by printing an electrically conductive antenna directly onto a packaging substrate and mounting a chip on the printed antenna.

[0409] This allows an RFID tag 110 to be incorporated into a packaged article by affixing this tag to the packaging substrate used to package the article.

[0410] This RFID tag 110 has the particularity of having a specially designed RFID antenna 28.

[0411] As shown in the experimental section, this design of the RFID antenna 28 allows for a better RR reading range.

[0412] The design also allows for better impedance matching.

[0413] Furthermore, this improvement in the behavior of the associated RFID tag is achieved with existing RFID tag manufacturing processes.

[0414] This manufacturing method is also compatible with other embodiments of the antenna which may be envisaged, and in particular embodiments comprising more pairs of lobes.

[0415] [Fig.7] illustrates another example of design of the RFID antenna 28.

[0416] In order to avoid repeating the same elements, only the differences between the example in [Fig.2] are indicated below.

[0417] In the case of [Fig.7], the antenna 28 comprises three pairs of lobes instead of one pair of lobes as in the example of [Fig.2].

[0418] This means that the antenna comprises the pair of lobes 52 of [Fig.2] and pairs 120 additional lobes.

[0419] The lobes of the additional lobe pairs 120 correspond to the side lobes 120 while the lobes already present in the case of [Fig.2] correspond to the primary lobes 52.

[0420] In the present case, the antenna 28 comprises four side lobes 120 and two primary lobes 52.

[0421] The design of the RFID antenna 28 remains symmetrical with respect to the first transverse direction X and the second transverse direction Y.

[0422] This implies that each primary lobe 52 is interposed between two side lobes 120.

[0423] An inter-lobe angle al22 between the side lobes 120 and the primary lobe 52 can be defined.

[0424] This inter-lobe angle a 122 is less than 90°, preferably less than 60°.

[0425] Furthermore, the dimensions of the side lobes 120 are smaller than those of the primary lobe 52. This applies to the length or width (maximum) of the side lobe 120.

[0426] [Fig.8] schematically illustrates fifteen other examples of antenna designs, which bear a Latin number from I to XV.

[0427] In the case of [Fig.8], each antenna I to XV comprises at least three pairs of lobes instead of one pair of lobes as in the example of [Fig.2].

[0428] All these examples have the same antenna length, which here is equal to 100 mm. This makes it easier to compare these examples.

[0429] These antennas differ in the number of lobe pairs, the width of the primary lobe and the inter-lobe angle, as shown in this table:

[0430] [Tables 1] Antenna example Number of lobe pairs Primary lobe width (mm) Interlobe angle (°) I 3 10 30 II 2 15 35 III 3 10 45 IV 3 10 60 V 5 10 30 VI 3 15 30 VII 3 10 35 VIII 3 15 45 IX 3 15 60 X 5 15 30 XI 3 20 30 XII 4 15 30 XIII 3 20 45 XIV 3 20 60 XV 5 20 30

[0431] Table 1: Some characteristics of antenna designs according to designs I to XV of [Fig.8]

[0432] As shown in the experimental section, this antenna design also allows to improve the reading range of an RFID tag.

[0433] EXPERIMENTAL SECTION

[0434] Several experiments were carried out by the applicant and are described below.

[0435] Hereinafter, unless otherwise indicated, all parts are by weight and all temperatures are in degrees Celsius.

[0436] Experiment 1 - performance of comparative examples

[0437] Using a Zebra ZT610 300 dpi thermal transfer printer supplied by Zebra Technologies Corporation of Lincolnshire, Illinois, the RFID antennas depicted in [Fig. 9] were printed on 4-inch-wide TRANSFERGLOSS PLUS RP51 40# WHITE KRAFT paper supplied by Raflatec Corporation of Mills River, North Carolina, using Me-tallograph® conductive thermal transfer ribbon supplied by Armor-IIMAK Corporation of Amherst, New York. The A conduction thermal transfer process using Metallograph® ribbon deposited a 0.245 micron thick conductive aluminum antenna onto the Transfergloss paper. The print speed on the ZT610 was 2 inches per second and the print energy was set to 28. Once printed, the conductive antenna was ready for use on the RFID tag.

[0438] A Higgs-3 RFID strip, supplied by Alien Technologies of San Jose, California, was attached to each of the printed RFID antennas in [Fig. 9]. The Higgs-3 RFID chip is a highly integrated, 800-bit memory UHF RFID tag single chip. The chip complies with the specifications of the global EPC Class 1 Gen 2. Two-part silver conductive epoxy adhesive number 8330D-19G 8330D supplied by MG Chemicals of Burlington, Ontario, Canada, was used to attach a Higgs-3 RFID chip-mounted strip to the antenna. Equal parts of the silver epoxy adhesive and initiator were dispensed onto a clean surface and mixed with a wooden stick for 30 seconds to ensure a smooth and homogeneous mixture. Using the wooden stick, a 3 mm x 3 mm layer of the mixed adhesive was applied to each foot of the chip box over the printed RFID antenna.The Higgs 3 RFID strip was then picked up using a vacuum pen and mounted onto the antennas so that the mounting pads on the Higgs RFID strip were aligned with the conductive epoxy applied to the antenna. The antenna with the mounted Higgs RFID strips was placed in a heat press set at 260°C and pressed for 45 minutes. The antennas and strips were then removed from the heat press and allowed to cool for at least 4 hours, after which it was found that the strips were well bonded to the antennas, which could then be flexed without the strip coming loose.

[0439] The impedance of a printed antenna was measured using the method described in the article "Impedance measurement for balanced UHF RFID tag antennas," Hailong Zu, YC Andrew Ko and Terry T. Ye, 2010 IEEE Radio and Wireless Symposium (RWS), New Orleans, LA, USA.

[0440] This method uses a vector network analyzer (VNA) and a custom probe ([Fig. 10]). The probe is designed so that it can be electrically connected to the antenna using spring connectors 300 to measure the impedance experienced by the chip. The signal from connectors 310 passes through coaxial cables 320 to connectors 330 that connect the probe to the VNA. The VNA is calibrated to simulate the attachment of the chip to read the approximate impedance. To calibrate a VNA, a custom 50 ohm load is used.

[0441] Measurements of the reading range of a given RFID tag were carried out in the large open space of a building with concrete walls, using a TURCK U Grok UHF RFID reader supplied by the TURCK company of Minneapolis (Minnesota). The reader, which operates in the 865-928 MHz range, is optimal for the required 915 MHz frequency. The orientation of the reader and tag can have a significant impact on the read range measurement, as the reader antenna is directional.

[0442] [Fig. 11] illustrates the directional radiation pattern of an RFID reader antenna. The maximum reading distance L can be achieved when the RFID tag is placed along the beam direction d. Consecutive measurements are made using a measuring tape between the reader and the RFID tag, until the reader is no longer able to read the tag.

[0443] Furthermore, the axis of symmetry 70 of the RFID antenna tag must be perpendicular to the direction of the beam d of the RFID reader for the measurements of the reading range RR.

[0444] The furthest distance at which the reader can read the tag is defined as the read range RR of the RFID tag.

[0445] RR read range measurements were performed with tags produced using the comparison antennas described in [Fig.9].

[0446] The experimental results are shown in Table 2, with the antenna length (dimension of the antenna along the first transverse direction X) and the antenna height (dimension of the antenna along the second transverse direction Y).

[0447] [Tables2] Comparative example Antenna design name Z (Ohm) Antenna length (mm) Antenna height (mm) RR (m) IA Skeleton H 63.6-12.6j 80 60 0 IB Dessymm 59.0-7.8j 80 60 0 IC SymmXY 55.6-6.9j 80 50 0.4 1D Symmspi 53.5-9.7j 80 50 0.6 1E Symmsploop 52.5-3.5j 80 30 0.7 1F SymmspX 48.8-12.8j 80 30 0.9 IG SymmCurrdist 50.9-3.4j 80 30 1.5 1H Symcommy 50.6-5.1j 80 30 1.75 11 Symcommxy 49.6-50.7d 80 40 1.5 U Squiggle-1 48.6-3,Ij 100 15 1.6 1% Squiggle-2 49.8-3,Ij 100 15 2.3 IL Squiggle-3 48.3-7.8d 100 15 1.7

[0448] Z: antenna impedance

[0449] Table 2: Performance of IA to IL antenna designs

[0450] As shown in Table 2, the reading ranges of these RFID antennas com relative values ​​vary from 0 to 2 meters.

[0451] Many comparative IA to IL antenna designs do not match the impedance of the Higgs chip used in these tags, which is 50-0j.

[0452] Comparative Examples II Symcommy and 1K Squiggle-2 have the closest impedance match and exhibit only modest reading ranges.

[0453] Experiment 2 - Examples according to [Fig.6]

[0454] Several variants named 2A to 2Y of the RFID antenna 28 having the design illustrated in [Fig. 6] were printed and mounted with RFID chips in a manner analogous to those of examples IA to IL. The measurements of the RR reading range and the impedance on these examples 2A to 2Y were also carried out in a manner analogous to those of examples IA to IL.

[0455] The results are presented in Table 3.

[0456] Examples 2A to 2Y all include a core circuit 50 to which a Higgs chip / strip 3 has been attached, as well as two antenna lobes, as shown in [Fig.6]. Unexpectedly, it has been found that the surface area of ​​the core circuit 50 and the lobes extending from the core circuit 50 contribute to the read range RR of the RFID tag.

[0457] As shown in Table 3, for antennas with measured impedance close to 50-0j, RFID tags with larger inductive circuits have a greater read range.

[0458] It has also been found that lobe width and length also strongly influence reading range. Lower ratios of lobe width to length (aspect ratio AR) contribute to increased reading range RR.

[0459] Comparing examples 2R and 2Y, it appears that the only parameter that varies is the value of the minimum width W52. The values ​​tested are respectively 4 mm, 3 mm, 2.5 mm, 2 mm, 1.5 mm, 1 mm and 0.5 mm.

[0460] The value of 2.5 mm (corresponding to example 2T) for the minimum width W52 seems to provide the largest RR reading range, namely 16.3 m. Indeed, when the minimum width W52 decreases from 2.5 mm to 0.5 mm (examples 2T to 2X), the RR reading range decreases from 16.3 m to 7 m. Similarly, when the minimum width W52 increases from 2.5 mm to 4 mm (examples 2R to 2T), the RR reading range increases from 16.3 m to 10 m.

[0461] It can also be emphasized that, whatever the value of the minimum width W52, all the RFID tags of examples 2R to 2Y have a greater reading range (compared to examples IA to IL).

[0462] Example 2Y is compared to Example 2T.

[0463] For Example 2T, the antenna was composed of 0.245 micron thick aluminum, while the antenna of Example 2Y was prepared using 50 micron thick aluminum foil, 3302 electrically conductive aluminum tape supplied by 3M of St. Paul, MN 55144-1000.

[0464] No significant difference was observed in the read range between Example 2T and Example 2Y, meaning that the thickness of the aluminum used to prepare the antenna did not impact its performance in the range of 0.245 microns to 50 microns.

[0465] [Tables3] Exem pie L28 (mm) MW52 (mm) L52 (mm) D58 (mm) D60 (mm) W52 (mm) A50 (mm2) AR Z28 («) RR (m) 2A 80 50 27,5 15 25 5 157,0 1,818 50-4j 5,0 2B 80 30 27,5 15 25 5 157,0 1,091 50-4j 7,0 2C 80 10 27,5 15 25 5 157,0 0,364 50-4j 12,5 2D 100 15 45,6 8 8,8 0,4 5,3 0,329 64-7j 3,4 2E 100 15 45 8 10 1 14,1 0,333 53,6- 3,8j 5,0 2F 100 15 44 8 12 2 31,4 0,341 49,2-3j 4,6 2G 100 15 43 8 14 3 51,8 0,349 49,6-3j 7,0 2H 100 15 41 12 18 3 70,7 0,366 52-2j 6,0 21 100 15 41 10 18 4 87,9 0,366 49-8, lj 10,0 2J 100 15 41 8 18 5 102,1 0.366 51-1, lj 4.5 2K 100 15 32.5 30 35 2 70.7 0.462 55+7j 7.0 2L 100 15 32.5 25 35 7.5 304.2 0.462 53-7j 5.0 2M 100 15 37.5 15 25 2 70.7 0.400 49.7-18j 8.8 2N 100 15 30 20 40 10 471.0 0.500 64-8, 6j 3.0 20 100 30 37.5 15 25 5 157.0 0.800 50-4j 7.5 2P 100 10 37.5 15 25 5 157.0 0.267 50-4j 14.0 2Q 100 20 37.5 15 25 5 157.0 0.533 50-4j 11.0 2R 100 15 37.5 15 25 4 157,0 0,400 51+2 2j 10 2S 100 15 37,5 15 25 3 157,0 0,400 50-0, 6j 12,5 2T 100 15 37.5 15 25 2.5 157.0 0.400 50-4d 16.3 2U 100 15 37.5 15 25 2 157.0 0.400 50-4d 14.7 Example L28 (mm) MW52 (mm) L52 (mm) D58 (mm) D60 (mm) W52 (mm) A50 (mm2) AR Z28 (“) RR (m) 2V 100 15 37.5 15 25 1.5 157.0 0.400 51-3d 11.5 2W 100 15 37.5 15 25 1 157.0 0.400 50+1 7d 12 2X 100 15 37.5 15 25 0.5 157.0 0.400 54-6d 7 2Y 100 15 37.5 15 25 2.5 157.0 0.400 50-4d 16.3

[0466] Z28: impedance of RFID antenna 28

[0467] Table 3: Performance of 2A to 2Y antenna designs

[0468] Experiment 3 - Examples according to [Fig.3]

[0469] Variants of the inventive RFID antenna 28, shown in [Fig. 3], were printed and mounted with RFID chips in a manner analogous to those of examples 1A to 11L.

[0470] Examples 3A to 3AQ all have an antenna length of 100 mm, a primary lobe width of 15 mm and variations in the dimensions of the central circuit 50.

[0471] As shown in Table 1, the comparative RFID tags have a read range of 2.3 meters or less. The 3A to 3AQ RFID tag examples were measured to have read ranges ranging from 3 meters to 16.3 meters.

[0472] Analysis of the data in Table 4 shows that several dimensional characteristics of the RFID antenna 2 / 8 according to Examples 3A to 3AQ contribute to obtaining reading ranges greater than 4.5 meters.

[0473] In particular, for antennas having an internal diameter D58 greater than 8 mm and less than or equal to 30 mm and a difference in diameter between the external periphery 60 and the internal periphery 58 of said central circuit 50 preferably greater than 5.0 mm, greater reading range performance has been observed.

[0474] For antennas whose area A50 of the central circuit 50 is less than 300 mm2, a greater reading range of the RR performance was observed.

[0475] For an antenna whose ratio of the surface A50 of the central circuit 50 and the surface A58 of the internal periphery 58, RI, is between 0.18 and 2.75, a better performance of the reading range RR is observed.

[0476] [Tables4] Exem pie D58 (mm) D60 (mm) AR D60-D58 m5 8 M5 8 A50 (mm2) A58 (mm2) Rl=A50 / A58 Z(Q) RR (m) 3A 20 40 0,5 0 20,00 10 20 471,00 157,00 3,00 64-8.6j 3 3B 8 8.8 0.3 3 0.80 4 4.4 5.28 25.12 0.21 64-7j 3.4 3C 7 12 0.3 4 5.00 3.5 6 37.29 19.23 1.94 58-3.2j 3.8 3D 7 10 0,3 3 3.00 3.5 5 20.02 19.23 1.04 48.2-6j 4.2 3E 8 18 0.3 7 10.00 4 9 102.05 25.12 4.06 48-12j 4.5 3F 8 18 0.3 7 10.00 4 9 102.05 25.12 4.06 48-12j 4.5 3G 19 20 0.3 8 1.00 9 10 22.77 134.24 0.17 56-122j 4.5 3H 7.5 12 0.3 4 4.50 3.7 6 34.74 21.78 1.59 48.7-12 7j 4.6 31 8 12 0.3 4 4.00 4 6 31.40 25.12 1.25 49.2+13 j 4.6 3J 7 15 0.3 5 8.00 3.5 7 63.19 19.23 3.29 47.4-7j 4.6 3K 8 12 0.3 4 4.00 4 6 31.40 25.12 1.25 49.2-3j 4.6 3L 8.5 10 0.3 3 1.50 4 6 20.41 26.69 0.76 52.8-3j 4.8 3M 8 10 0.3 3 2.00 4 6 21.98 25.12 0.88 51.8-24j 5 3N 8.5 12 0.3 4 3.50 4 6 29.83 26.69 1.12 52-9j 5 30 8 10 0.3 3 2.00 4 5 14.13 25.12 0.56 53.6-3.8 j 5 3P 25 35 0.4 6 10.00 12.5 20 304.19 245.31 1.24 53-7j 5 3Q 7.5 10 0.3 3 2.50 3.7 5 17.47 21.78 0.80 52-17j 5.1 3R 7.5 15 0.3 5 7.50 3.7 7 60.64 21.78 2.78 52+35j 5.2 3S 9 11 0.3 4 2.00 4 6 23.55 28.26 0.83 49-2j 5.6 3T 12 18 0.3 7 6.00 6 9 70,65 56,52 1,25 52-2j 6 3U 18 20 0,3 8 2,00 9 10 29,83 127,17 0,23 56-94j 6 3V 9 12 0,3 4 3,00 4 6 28,26 28,26 1,00 51+61j 6.8 3W 9.5 11 0.3 4 1.50 4.5 6 18.25 33.56 0.54 50+132j 7 3X 8 15 0.3 5 7.00 4 7 57.31 25.12 2.28 51-2J 7 3Y 8 14 0,3 5 6.00 4 7 51.81 25.12 2.06 49.6-3J 7 3Z 30 35 0.4 6 5.00 4 6 70.65 94.20 0.75 55+7j 7 3 AA 8.5 15 0.3 5 6.50 4 7 55.74 26.69 2.09 51-2j 7.3 3AB 17 20 0.3 8 3.00 8 10 50.24 106.76 0.47 52-36j 8 3AC 9.5 12 0.3 4 2.50 4.5 6 22.96 33.56 0.68 49-19j 8.5 3AD 15 25 0.4 0 10.00 4 6 70.65 47.10 1.50 49.7- 18j 8.8 3AE 9 15 0.3 5 6.00 4 7 54.17 28.26 1.92 49.4+3j 9 3AF 9.5 15 0.3 5 5.50 4.5 7 48.87 33.56 1.46 50+64j 9 3AG 10 18 0.3 7 8.00 5 9 87.92 39.25 2.24 49.8-Ij 10 Exem pie D58 (mm) D60 (mm) AR D60-D58 m5 8 M5 8 A50 (mm2) A58 (mm2) A50 / A58 Z(Q) RR (m) 3AH 16 20 0.3 8 4.00 8 10 56.52 100.48 0.56 48-12J 10 3AI 18 25 0.4 0 7.00 4 6 61.23 56.52 1.08 48-19J 10 3AJ 19 25 0.4 0 6.00 4 6 58.09 59.66 0.97 48-12J 10 3AK 19 29 0.4 2 10.00 9 14 184.48 134.24 1.37 49-17J 12 3AL 17 27 0.4 1 10.00 8 13 168.78 106.76 1.58 51-0.00 2J 12.8 3AM 18 28 0.4 2 10.00 9 14 180.55 127.17 1.42 51-0,U 13 3AN 16 25 0.4 0 9.00 4 6 67.51 50.24 1.34 51-8J 14 3AO 17 25 0.4 0 8.00 4 6 64.37 53.38 1.21 50-62J 14 3AP 16 26 0.4 1 10.00 8 13 164.85 100.48 1.64 50-30J 15 3AQ 15 25 0.4 0 10.00 7.5 12.5 157.00 88.31 1.78 50-4J 16.3

[0477] Tableau 4: Performances of conceptions from 3A to 3AQ

[0478] Experience 4 - Exemplars used [Fig.4]

[0479] Variants of the inventive RFID antenna 28, shown in [Fig. 4], were printed and mounted with RFID chips in a manner analogous to those of Examples 1A to 11. The reading range and impedance measurements of these examples were also performed in a manner analogous to those of Example 1 and are summarized in Table 5.

[0480] Example 4A demonstrates that a rectangular inductive circuit can be used and a high reading range can still be achieved.

[0481] Example 4d shows that the orientation of the inductive circuit can be changed and that a high reading range can still be achieved.

[0482] Comparison of Examples 4C and 4D also shows that a small aspect ratio AR is desirable.

[0483] [Tables5] Example Antenna L28 (mm) MW52 (mm) L28 (mm) AR A50 (mm2) Z(Q) RR (m) 4A Figure 4 example D 100 15 37.5 0.40 200 51.3+0.4 j 10 4B Figure 4 example B (rotated) 100 15 42.5 0.35 157 52.9+6.8 d 10 4C Figure 4 example B 100 15 37.5 0.40 157 50-4d 14.6 4D Figure 4 example B 100 35 35 1.00 226 51.3+0.6 d 6.5

[0484] Table 5: Performance of 4A to 4D antenna designs

[0485] Experiment 5 - Influence of the number of lobes

[0486] Several variants of the RFID antenna 28 with multi-lobe designs, shown in [Fig. 8], were printed and mounted with RFID chips in a manner analogous to those in Experiment 1. The read range and impedance measurements on these examples were also performed in a manner analogous to those in Experiment 1. The corresponding results are summarized in Table 6.

[0487] Examples 2T and 5A, with 2 and 4 lobes respectively, were composed of lobes which all had a length of 37.5 mm and a maximum width MW52 of 15 mm. Example 5A has a total of 4 lobes, two on each side of the inductive circuit. The angle α between the two lobes on each side was 30°. Examples 5B to 5D had two primary lobes, one on each side of the inductive circuit, in a mirror-like manner. The dimensions of these primary lobes were L52 = 42 mm and MW52 = 15 mm.

[0488] The side lobes of Examples 5B to 5D were placed symmetrically with respect to the primary lobes with an angle a of 30° between all the lobes on each side of the inductive circuit. The dimensions of these side lobes were SideL = 22 mm and SideW = 10 mm. The decrease in reading range as a function of increasing the number of lobes is significant, with a reduction of more than 50% for 10-lobe antennas.

[0489] [Tableauxô] Example No. of lobes L28 (mm) D60 (mm) al2 2 (°) MW5 2 (mm) L52 (mm) W side (mm ) L side (mm ) A50 (mm2 ) AR Z (“) RR (m) 2T 2 100 15 - 15 37.5 - - 157.0 0.4 0 50-4 j 16.3 5A 4 100 30 30 15 37.5 15 37 157 0.4 0 50-0 .89d 15.3 5B 6 100 26 30 15 37.5 10 22 157 0.4 0 51-1 2d 10 5C 8 100 60 30 15 37.5 10 22 157 0.4 0 54-8 d 7 5D 10 100 36 30 15 37.5 10 22 157 0.4 0 52-7 5d 6.8

[0490] Table 6: Performance of 5A to 5D antennas compared to 2T antenna

[0491] Example 6 - Influence of the thickness of the primary lobe and the angle between the lobes

[0492] Several variations of the inventive RFID antenna 28 with 6 lobes, illustrated in [Fig.7], were printed and mounted with RFID chips in a manner analogous to those of Example 1. The read range and impedance measurements of these examples were also carried out in a manner analogous to those of Example 1 and are summarized in Table 7. Examples 5C and 6A to 6N included two primary lobes, one on each side of the inductive circuit, mirrored, and four side lobes, two on each side of the inductive circuit.

[0493] Examples 5C and 6A to 6K included primary lobes of L52=37.5 mm and MW52 varying from 10 mm to 15 mm and side lobes of SideL = 22 mm and SideW of 10 mm. The angle al22 between the lobes on each side varied from 30° in Example 5C to 60° in Example 6c. This angle al22 did not have a significant impact on the maximum reading range.

[0494] Examples 6D to 6G included primary lobes of L L52=42 mm and MW52=10 mm and side lobes of SideL = 22 mm and SideW of 10 mm. The angle al22 between the lobes on each side varied from 30° in Example 5C to 60° in Example 6C. This angle al22 did not have a significant impact on the maximum read range.

[0495] Examples 6H to 6K included primary lobes of L L52=37.5 mm and MW52=20 mm and side lobes of SideL = 22 mm and SideW of 10 mm. The angle a 122 between the lobes on each side varied from 30° in example 5H to 60° in example 6K. This angle al22 did not have a significant impact on the maximum reading range.

[0496] The side lobe dimensions were kept constant throughout CôtéW = 10 mm and SideL =22 mm for all antennas in Examples 6C, 6G, 6K, and 6L to 6N. The dimensions of the primary lobes vary such that the radio aspect ratio AR varies from 0.27 to 0.53 for the 6-lobe and 10-lobe antennas in Examples 6C, 6G, 6K, and 6H to 6N. As shown in Table 7, as the aspect ratio AR increases, the read range decreases analogously for the 10-lobe antennas. 6-lobe and 10-lobe antennas. 10-lobe antennas have a shorter read range than 6-lobe antennas.

[0497] [Tables?] Example s No. of lobes L28 (mm) D60 (mm) al2 2 (°) MW5 2 (mm) L52 (mm) Side W (mm ) Side L (mm) A50 (mm2 ) AR Z (“) RR (m) 5C 6 100 26 30 15 37.5 10 22 157 0.4 0 51-1 2d 10 6A 6 100 26 35 15 37.5 10 22 157 0.4 0 51-1 16d 11 6B 6 100 32 45 15 37.5 10 22 157 0.4 0 52-6 d 11 6C 6 100 36 60 15 37.5 10 22 157 0.4 0 54-9 .8d 10 6D 6 100 26 30 10 37.5 10 22 157 0.2 7 51-3 d H, 6 6E 6 100 28 35 10 37.5 10 22 157 0.2 7 51-0.6d 12.5 6F 6 100 32 45 10 37.5 10 22 157 0.2 7 53-4d 11 6G 6 100 36 60 10 37.5 10 22 157 0.2 7 57-9d 8 6H 6 100 26 30 20 37.5 10 22 157 0.5 3 62-1 9.8d 4 61 6 100 28 35 20 37.5 10 22 157 0.5 3 55-1 6d 9 6d 6 100 32 45 20 37.5 10 22 157 0.5 3 58-0.42d 6 6K 6 100 36 60 20 37.5 10 22 157 0.5 3 59-8d 5 6L 10 100 34 30 10 37.5 10 22 157 0.2 7 54-0.8d 6 6M 10 100 36 30 15 37.5 10 22 157 0.4 0 52-7 5d 6.8 6N 10 100 37 30 20 37.5 10 22 157 0.5 59-2 5 3 2d Table 7: Performance of 6A to 6N antennas compared to 5A antenna

[0498]

Claims

Claims

1. RFID antenna (28) comprising: - a central inductive circuit (50), and - at least two lobes (52, 120) extending radially from the central inductive circuit (50), a minimum width being defined for each lobe (52), the minimum width of each lobe (52) being greater than 0.1 mm.

2. An RFID antenna according to claim 1, wherein each lobe (52, 120) belongs to a respective lobe pair, two lobes (52, 120) of the same lobe pair being symmetrical with respect to the central inductive circuit (50).

3. RFID antenna according to claim 1 or 2, wherein the at least two lobes (52, 120) comprise primary lobes (52) and at least one side lobe (120), the angle between the side lobe (120) and one of the primary lobes (52) being less than 90°, preferably less than 60°.

4. An RFID antenna according to claim 3, wherein the angle between the side lobe (120) and one of the primary lobes (52) is less than 60°.

5. An RFID antenna according to claim 3 or 4, wherein a width and a length are defined for each lobe (52), the width of each side lobe (120) being less than the smallest width of the primary lobes (52) and the length of each side lobe (120) being less than the smallest length of the primary lobes (52).

6. An RFID antenna according to any one of claims 1 to 5, wherein the area of ​​the central inductive circuit (50) is less than 300 mm2.

7. An RFID antenna according to any one of claims 1 to 6, wherein the central inductive circuit (50) extends between an inner periphery and an outer periphery, the ratio between the surface area of ​​the central inductive circuit (50) and the surface area of ​​the inner periphery being between 0.18 and 2.

75.

8. An RFID antenna according to any one of claims 1 to 7, wherein an aspect ratio is defined for each lobe (52), the aspect ratio of each lobe (52) being between 0.25 and 2.

00.

9. The RFID antenna of claim 8, wherein the aspect ratio of each lobe (52) is less than 1.

00.

10. An RFID antenna according to any one of claims 1 to 9, wherein the central inductive circuit (50) extends from an inner periphery to an outer periphery for which respective diameters are defined, the diameter of the inner periphery being between 8.0 mm and 20.0 mm.

11. The RFID antenna of claim 10, wherein the difference between the diameters of the inner periphery and the outer periphery is greater than 5.0 mm.

12. An RFID antenna according to any one of claims 1 to 11, wherein the lobes (52) and the central inductive circuit (50) are made of the same conductive material.

13. The RFID antenna of any one of claims 1 to 12, wherein a length is defined for the RFID antenna (28), the length of the RFID antenna (28) being greater than 40 mm.

14. The RFID antenna of claim 13, wherein the length of the RFID antenna (28) is between 80 mm and 100 mm.

15. RFID antenna according to any one of claims 1 to 14, wherein the RFID antenna (28) is adapted to receive and transmit signals at frequencies belonging to a frequency range extending from 860 MHz to 960 MHz.

16. An RFID tag (110) comprising an RFID antenna (28) according to any one of claims 1 to 15, and an RFID chip (100) wherein said RFID chip (100) is electrically connected to the central inductive circuit (50) of said RFID antenna (28).

17. A method of manufacturing an RFID tag (110), the manufacturing method comprising a step of forming an RFID antenna (28) on a substrate, the RFID antenna (28) comprising: - a central inductive circuit (50), and - at least two lobes (52, 120) extending radially from the central inductive circuit (50), a minimum width being defined for each lobe (52), the minimum width of each lobe (52) being greater than 0.1 mm, the forming step being carried out using a method selected from conductive metal transfer printing, conductive inkjet printing and conductive screen printing.

18. A method of manufacturing an RFID tag according to claim 17,

19. the manufacturing process comprising: - cutting the RFID antenna (28) from a sheet of metal, and - fixing by gluing the RFID antenna (28) to the substrate. A method of manufacturing an RFID tag according to claim 17, the manufacturing method comprising: - a step of providing a metallized substrate with a continuous layer of metal, - a step during which the metal of the substrate is removed outside the areas dedicated to the formation of the RFID antenna (18) using a chemical technique or mechanical etching.

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