Wireless communication device

Abstract

To provide a wireless communication device capable of further improving communication performance. 【Solution means】A wireless communication device 10 of a battery-free wire type including a radiator 11, with one end of a pair of impedance matching units 18 and 19 connected to both sides of the radiator 11 avoiding the central portion in the longitudinal direction, respectively. The other ends of the impedance matching unit 18 and the impedance matching unit 19 are insulated by forming a gap 24 or arranging an insulating material, and are connected via an IC element 25 recording unique information.

Description

Technical Field

[0001] The present invention relates to a wireless communication device including a radiator.

Background Art

[0002] In a manufacturing factory or the like, an RF tag may be used for identifying and managing products or the like. By attaching an RF tag embedded with unique information to a product or the like and having a reader / writer exchange information with the RF tag through wireless communication, it is possible to realize the logistics management and position management of the product or the like. As RF tags, there are an active type driven by a built-in battery and a passive type that does not have a battery and is driven using radio waves received from the outside as an energy source. This active type RF tag can have a long communication distance, but has a high unit price and requires grasping the remaining capacity of the built-in battery. On the other hand, the passive type RF tag has a low unit price and does not require grasping the remaining capacity of the battery, but generally has a communication distance of about 5 m to 6 m, and depending on the application, it is required to extend the communication distance. Therefore, the present inventors have proposed several novel wireless communication devices so far (see Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] With the above wireless communication device, it was possible to extend the communication distance and improve the wireless communication function, but further performance improvement has been desired. An object of the present invention is to provide a wireless communication device capable of further improving communication performance.

Means for Solving the Problem

[0005] In order to further improve the performance of wireless communication devices, the inventors of the present invention have conceived the present invention by conducting various studies on the configuration of the radiator.

[0006] That is, the present invention is as follows. [1] A wireless communication device of a non-powered wire type equipped with a radiator, One ends of a pair of impedance matching portions A and B are respectively connected to both sides of the radiator avoiding the central portion in the longitudinal direction, and the other ends of the impedance matching portion A and the impedance matching portion B are insulated by forming a gap or arranging an insulating material, and are connected via an IC element recording unique information. A wireless communication device characterized by this.

[0007] [2] The impedance matching portion A has a conductor portion A arranged in parallel with the radiator and a matching adjustment portion A connecting the radiator and the conductor portion A, The impedance matching portion B has a conductor portion B arranged in parallel with the radiator and a matching adjustment portion B connecting the radiator and the conductor portion B, The wireless communication device according to [1] above, characterized in that the conductor portion A and the conductor portion B are in the insulated state and are connected via the IC element. [3] The radiator, the impedance matching portion A, and the impedance matching portion B are respectively arranged on an insulating substrate, The wireless communication device according to [2] above, characterized in that the conductor portion A and the conductor portion B are printed wirings formed on the substrate. [4] The wireless communication device according to [3] above, characterized in that the matching adjustment portion A and the matching adjustment portion B are printed wirings formed on the substrate. [5] The wireless communication device according to [2] or [3] above, wherein the matching adjustment unit A and the matching adjustment unit B are bar-shaped conductors, and the distance between the opposing bar-shaped conductors is adjustable.

[0008] [6] The wireless communication device according to [1] above, wherein the impedance matching unit A and the impedance matching unit B have wire materials of conductors.

[0009] [7] The wireless communication device according to any one of [1] to [6] above, further comprising a reflector arranged in parallel on one side of the radiator and a waveguide arranged in parallel on the other side of the radiator.

[0010] [8] The wireless communication device according to [7] above, wherein the impedance matching unit A and the impedance matching unit B are arranged obliquely around the axis of the radiator. [9] The wireless communication device according to [8] above, wherein the impedance matching unit A and the impedance matching unit B are arranged obliquely within a range of more than 0 degrees and 120 degrees or less from the waveguide side toward the reflector side.

[10] The wireless communication device according to [9] above, wherein the impedance matching unit A and the impedance matching unit B are arranged obliquely at 90 degrees.

[0011]

[11] The wireless communication device according to any one of [7] to

[10] above, wherein a plurality of the waveguides are arranged in parallel. [Advantages of the Invention]

[0012] According to the wireless communication device of the present invention, the communication performance can be improved. [Brief Description of the Drawings]

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0014] The wireless communication device of the present invention is a wireless power feeding line type wireless communication device provided with a radiator, and one ends of a pair of impedance matching portions A and B are respectively connected to both sides avoiding the central portion in the longitudinal direction of the radiator, and the other ends of the impedance matching portion A and the impedance matching portion B are insulated by forming a gap or arranging an insulating material, and are connected via an IC element recording unique information. Here, the wireless power feeding line type means a passive type that is not provided with a power feeding line (coaxial cable) in the device and is driven using radio waves received from the outside as an energy source.

[0015] By using the wireless communication device of the present invention, further improvement in communication performance can be achieved. In addition, the wireless communication device of the present invention is of a balanced power supply type powered by both the paired impedance matching unit A and impedance matching unit B. Since both sides of the IC element are respectively connected to the paired impedance matching unit A and impedance matching unit B, the connection strength can be improved and mass production becomes easier. This wireless communication device is a device that can be widely used for logistics management and position management of products and the like.

[0016] Hereinafter, each member of the wireless communication device of the present invention will be described. Theoretically, the wireless communication device can be composed of only a radiator, but it is preferably configured to further include a reflector arranged in parallel on one side thereof and a waveguide arranged in parallel on the other side with respect to the radiator. Also, it can be configured to have a radiator and a reflector (the waveguide is not required), or it can also be configured to have a radiator and a waveguide (the reflector is not required). Note that it is preferable that a plurality of waveguides are arranged in parallel. It is preferable that each of this radiator, reflector, and waveguide is immovably attached and fixed to a support that supports the radiator, reflector, and waveguide.

[0017] (Radiator) The radiator preferably has a single round bar that serves as an element functioning as a radiator (basically, the configuration of a dipole antenna). By configuring the radiator with a round bar in this way, electrical superiority can be obtained compared to other shapes. The round bar is a columnar bar with a circular cross-section (solid and not hollow (pipe)), and examples of its material include metals such as aluminum alloy, stainless steel, and brass. Considering ease of transportation (weight reduction), etc., it is preferably composed of an aluminum alloy. The diameter of this round bar is, for example, about 3 mm to 10 mm. The larger the diameter, the easier it is to obtain the skin effect (the easier it is for current to flow). However, considering ease of transportation, etc., about 3 mm to 7 mm is preferable. Note that the cross-sectional shape of the round bar is a perfect circle, but it may also be an ellipse or the like.

[0018] (Impedance Matching Unit) The paired impedance matching units A and B (hereinafter also simply referred to as impedance matching units) are parts that function to adjust (match) the impedance between the radiator side and the IC element, and it is preferable that they are symmetrically arranged on one side (side) of the radiator, centered on the longitudinal center of the radiator (see FIGS. 1(a) and 1(b)). It is preferable to perform the adjustment of the impedance between the radiator side and the IC element, for example, while checking the operation of the wireless communication device. As the adjustment method, for example, adjusting the ratio of the thickness (width) between the radiator and the impedance matching unit, adjusting the distance between the radiator and the impedance matching unit, adjusting the length of the impedance matching unit, etc. can be mentioned.

[0019] The impedance matching unit preferably has, for example, a round bar (a cylindrical shape with a circular cross-section (solid and not hollow (pipe))), a plate material, or a wire material. As the material, for example, metal products such as aluminum alloy, stainless steel, copper, and copper alloy can be mentioned. The width of this impedance matching unit (diameter in the case of a round bar or a wire) is preferably made narrower than the width of the radiator (width of the round bar). When the impedance matching unit has a round bar and a wire, for example, it is preferably set to a width of 50% or less of the width of the radiator, more preferably 30% or less of the width, and even more preferably 25% or less of the width (specifically, it is particularly preferable to set it to a width of about 1 mm or less).

[0020] The state where the other end of the impedance matching unit A and the other end of the impedance matching unit B are in an insulating state can be achieved by forming a gap (air layer) between the impedance matching unit A and the impedance matching unit B. In particular, it is preferably implemented by arranging an insulating material in terms of manufacturing. Here, examples of the insulating material include a plastic sheet material, paper, a cured resin (filling a liquid resin into the gap and curing), etc., but it is not particularly limited as long as it can be in an insulating state. The distance between the end faces of the other ends of the opposing impedance matching section A and the other end of the impedance matching section B (see the interval d in FIGS. 2(a) and 2(b)) can improve the performance of the radiator the narrower it is. Therefore, for example, 3 mm or less is preferable, 1 mm or less is more preferable, 500 μm or less is still more preferable, and 300 μm or less is particularly preferable. On the other hand, the lower limit is more than 0 μm, but in reality, about 100 μm is sufficient. When using the above-mentioned insulating material, the thickness of the insulating material may be adjusted to the above dimensions.

[0021] The impedance matching section A and the impedance matching section B are electrically connected via an IC element (IC chip, semiconductor). The IC element has a well-known structure based on silicon (Si), a discrimination code which is unique information is recorded (encoded), and the stored discrimination code is wirelessly transmitted to the outside by the electromotive force obtained by receiving radio waves from the antenna. For this IC element, a sheet-like wiring substrate can be used, specifically, a region including the IC element cut out from a commercially available RF tag (seal tag, inlay), but an IC element with unique information recorded thereon can also be used. The cutting out of the IC element from this commercially available RF tag is preferably performed so as to exclude the antenna portion together with the wiring formed on the sheet-like substrate (patterned and integrated with the sheet-like substrate).

[0022] The connection of the IC element to the impedance matching section can be carried out using the wiring formed on the sheet-like wiring substrate, or can also be carried out using a conductor (copper wire, etc.) separately connected to the IC element. The mounting position with respect to the impedance matching portion of this wiring or conductor (hereinafter also referred to as wiring etc.) is such that the closer it is to the end faces on the opposite sides of the impedance matching portion A and the impedance matching portion B, the better the performance of the radiator. Therefore, it is preferably in the range up to 10 mm from the end faces, more preferably in the range up to 5 mm, still more preferably in the range up to 2 mm, and particularly preferably in the range up to 1 mm, for example, at the ends on the opposite sides of the impedance matching portion A and the impedance matching portion B. In addition, the attachment of the wiring etc. to the impedance matching portion is not particularly limited as long as the wiring etc. does not come off from the impedance matching portion. For example, it can be carried out using an adhesive tape, resin (adhesive), solder, etc.

[0023] (Reflector) The reflector preferably has a round bar that serves as an element functioning as a reflector. The reflector is arranged parallel to one side of the radiator (see FIGS. 1(a) and 1(b)). The round bar constituting the reflector is a cylindrical bar with a circular cross-section (solid and not hollow (pipe)), and examples of its material include metals such as aluminum alloy and stainless steel. Considering ease of transportation (weight reduction), etc., it is preferably made of aluminum alloy. The diameter of this round bar is preferably about 3 mm to 10 mm, and more preferably about 4 mm to 7 mm, for example.

[0024] (Waveguide) The waveguide preferably has a round bar that serves as an element functioning as a waveguide. The waveguide is arranged parallel to the other side of the radiator (see FIGS. 1(a) and 1(b)). The round bar constituting this waveguide may be one, or may be a plurality of three or more, and a practical upper limit is about ten. In this way, by making the number of waveguides plural, the communication distance can be further extended. The round bar that constitutes the waveguide is a cylindrical bar with a circular cross-section (solid, not hollow (pipe)), and examples of its material include metals such as aluminum alloy and stainless steel. Considering ease of transportation (weight reduction), etc., it is preferably made of aluminum alloy. The diameter of this round bar is preferably about 3 mm to 10 mm, and more preferably about 4 mm to 7 mm.

[0025] (Lengths of radiator, reflector, and waveguide, etc.) Regarding the lengths of the above-described radiator, reflector, and waveguide, it is preferable that the length L2 of the reflector is slightly longer and the length L3 of the waveguide is slightly shorter with reference to the length L1 of the radiator (see Fig. 1(a)). Specifically, since the frequency of the radio wave used for the IC element recording the unique information is 920 MHz, the wavelength λ is 32.6 cm, so the length L1 of the radiator is 163.0 mm (=λ / 2). With reference to this length L1 of the radiator, it is preferable to adjust the length L2 of the reflector and the length L3 of the waveguide while performing operation confirmation. For example, the length L2 is made several mm (5 mm or less) longer than the length L1, and the length L3 is made several mm (5 mm or less) shorter than the length L1. When arranging a plurality of round bars functioning as waveguides, it is preferable to gradually shorten each length (by about several mm (5 mm or less)) in the direction away from the radiator.

[0026] (Lengths of impedance matching sections, etc.) The total length of the impedance matching section A and the impedance matching section B (or the total length of the conductor section arranged in parallel with the radiator) is shorter than the length L1 of the radiator, and it is preferable that the lengths of the impedance matching section A and the impedance matching section B are the same (see Fig. 1(a)). Specifically, since the frequency of the radio wave used for the IC element recording the unique information is 920 MHz, the wavelength λ is 32.6 cm. Therefore, the total length of the portion parallel to the radiators of the impedance matching section A and the impedance matching section B is 81.5 mm (= λ / 4), and the lengths of the impedance matching section A and the impedance matching section B are each 40.8 mm (= λ / 8). Based on this length, it is preferable to adjust while performing an operation check.

[0027] (Feature) The wireless communication device of the present invention has a structure without a feeding line, and the whole functions as a passive type RF tag. Thus, since a feeding line is not required, the length of the radiator can be made the theoretical length, so that designs such as wavelength shortening can be omitted (simplification and facilitation of the design can be achieved). As a result, it can be manufactured efficiently, the performance can be improved, and the quality can be stabilized.

[0028] Hereinafter, embodiments of the wireless communication device of the present invention will be specifically described with reference to the drawings, but the present invention is not limited to these embodiments.

[0029] As shown in FIGS. 1(a) and 1(b), the wireless communication device 10 according to the first embodiment of the present invention includes a radiator 11, a reflector 12, and a waveguide 13, and is a device attached to a support 14 such that the reflector 12 and the waveguide 13 are respectively arranged on both sides of the radiator 11. Here, since directivity is obtained in the direction of the waveguide 13 as viewed from the radiator 11, the following description will be made with the directivity direction D (refer to the arrows in FIGS. 1(a) and 1(b)) as the front.

[0030] The wireless communication device 10 has a radiator 11 with a single metal round bar 15, a reflector 12 with a single metal round bar 16, two waveguides 13 each having a single metal round bar 17, and is mounted and fixed to a support 14 made of a prismatic material (bar material) of metal or plastic such that, in plan view, the axes are aligned in a direction orthogonal to the longitudinal direction of the support 14. Here, the material, shape (cross-sectional shape), etc. of the support 14 are not particularly limited as long as the radiator 11, reflector 12, and waveguides 13 can be mounted and fixed and the wireless communication device 10 can function.

[0031] One end of an impedance matching section 18 (impedance matching section A) and an impedance matching section 19 (impedance matching section B) are respectively connected to both sides of the radiator 11 avoiding the central portion in the longitudinal direction thereof, and the other ends of the impedance matching section 18 and the impedance matching section 19 are arranged to face each other in an insulated state.

[0032] The impedance matching section 18 has a conductor section 20 (conductor section A) arranged in parallel with the radiator 11 and a matching adjustment section 21 (matching adjustment section A) connecting the radiator 11 and the conductor section 20, and the impedance matching section 19 has a conductor section 22 (conductor section B) arranged in parallel with the radiator 11 and a matching adjustment section 23 (matching adjustment section B) connecting the radiator 11 and the conductor section 22, and the conductor section 20 and the conductor section 22 are in an insulated state. The conductor section 20 and the conductor section 22 are each composed of a metal round bar, and the matching adjustment section 21 and the matching adjustment section 23 are each composed of a metal bar material. Examples of such bar materials include round bars, square bars, and plate materials.

[0033] The paired conductor section 20 and conductor section 22 are arranged in an insulated state with their axes aligned (on the same axis). Here, "with their axes aligned" includes not only the case where the axis of the conductor section 20 and the axis of the conductor section 22 are exactly the same, but also the case where there is a slight deviation as long as the functions of the impedance matching section 18 and the impedance matching section 19 are not impaired. The total length of the conductor part 20 and the conductor part 22 (= λ / 4) is approximately the same as the length of the central part in the longitudinal direction of the radiator 11 (round bar 15). As shown in FIGS. 1(a), 2(a), and (b), the conductor part 20 and the conductor part 22 are arranged with a gap 24 (interval d) between their end faces, and are connected by a sheet-like wiring substrate 26 on which the IC element 25 is mounted.

[0034] The matching adjustment part 21 is arranged orthogonally to the radiator 11 and the conductor part 20, and the matching adjustment part 23 is arranged orthogonally to the radiator 11 and the conductor part 22. As a result, the matching adjustment part 21 and the matching adjustment part 23 are arranged in parallel, but they can also be arranged non-parallel. The matching adjustment part 21 and the matching adjustment part 23 are attached and fixed to specific positions of the radiator 11, the conductor part 20, and the conductor part 22, but they can also be made movable with respect to the radiator 11, the conductor part 20, and the conductor part 22. Thereby, the interval between the opposing matching adjustment part 21 and the matching adjustment part 23 can be adjusted, and the impedance can be adjusted.

[0035] The attachment and fixation of the above-mentioned round bar 15, impedance matching part 18 (conductor part 20 and matching adjustment part 21), and impedance matching part 19 (conductor part 22 and matching adjustment part 23) to the support 14 can be implemented by arranging them on a support base 28 attached and fixed to the upper surface of the support 14 and screwing them (not shown), etc., but it is not particularly limited as long as it can be attached and fixed to the support 14. Note that the round bar 15, impedance matching part 18, and impedance matching part 19 on the support base 28, and the sheet-like wiring substrate 26 on which the IC element 25 is mounted are exposed to the outside, but it is preferably covered with a cover material or the like, for example. Also, the impedance matching part 18 (conductor part 20 and / or matching adjustment part 21), and the impedance matching part 19 (conductor part 22 and / or matching adjustment part 23), and the sheet-like wiring substrate 26 on which the IC element 25 is mounted can be coated with resin or the like and integrated.

[0036] Here, as shown in FIG. 3(a), it is preferable to arrange the impedance matching unit 18 and the impedance matching unit 19 in an inclined manner about the axis of the radiator 11 (round bar 15). FIG. 3(b) shows the result of measuring the received radio wave intensity (RSSI: Received Signal Strength Indicator) while changing the inclination angles of the impedance matching unit 18 and the impedance matching unit 19 from the waveguide side toward the reflector side, using a wireless communication device having only the radiator 11 to which the impedance matching unit 18 and the impedance matching unit 19 are connected, with the communication distance (distance between radiators) to an antenna (reader) being 50 cm.

[0037] In the measurement of the received radio wave intensity, for the wireless communication device having only the radiator 11, the length of the radiator 11 was set to 163 mm, the lengths of the conductor part 20 of the impedance matching unit 18 and the conductor part 22 of the impedance matching unit 19 were each set to λ / 8 (diameter 4 mm × 40.5 mm), and a device in which the distance between the radiator 11 and the conductor part 20 (corresponding to the length of the matching adjustment part 21) and the distance between the radiator 11 and the conductor part 22 (corresponding to the length of the matching adjustment part 23) were each set to 8 mm was used. Also, for the antenna, an antenna composed of three elements (one radiator, one reflector, and one waveguide) provided with a feeding line was used.

[0038] As shown in Fig. 3(b), the received radio wave intensity increases as the tilt angle of the impedance matching section increases, reaches its maximum at a tilt angle of 90 degrees, and then tends to decrease. Specifically, the tilt angle from the waveguide side toward the reflector side is preferably within a range greater than 0 degrees and less than or equal to 120 degrees, more preferably within a range of 30 degrees or more and 100 degrees or less, even more preferably within a range of 60 degrees or more and 100 degrees or less, particularly preferably within a range of 80 degrees or more and 95 degrees or less, and most preferably 90 degrees (arranged so as to be perpendicular to the plane including the reflector and the waveguide in a side view (in an upright state)). Here, 90 degrees does not only mean exactly 90 degrees, but preferably includes cases where there is a deviation within a range of ±3 degrees, more preferably within a range of ±2 degrees, and even more preferably within a range of ±1 degree.

[0039] As shown in Figs. 1(a) and (b), behind the radiator 11, a metal round bar 16 that functions as a reflector 12 is arranged in parallel with the round bar 15 that functions as the radiator 11. The attachment and fixation of this round bar 16 to the support 14 can be achieved by passing through and screwing the support base 30 attached and fixed to the upper surface of the support 14 by the holding means 29. However, as long as the round bar 16 can be attached and fixed to the support 14, it is not particularly limited.

[0040] As shown in Figs. 1(a) and (b), on the side opposite to the reflector 12 with the radiator 11 interposed therebetween, that is, in front of the radiator 11, two metal round bars 17 that function as waveguides 13 are arranged in parallel with the round bars 15 and 16. The attachment and fixation of this round bar 17 to the support 14 can be achieved by passing through and screwing the support base 32 attached and fixed to the upper surface of the support 14 by the holding means 31. However, as long as the round bar 17 can be attached and fixed to the support 14, it is not particularly limited.

[0041] As shown in Fig. 1(a), the lengths of the radiator 11 (round bar 15), reflector 12 (round bar 16), and waveguide 13 (round bar 17) described above are such that the length L2 of the reflector 12 is slightly longer and the length L3 of the waveguide 13 is slightly shorter than the length L1 of the radiator 11. Also, the distance S1 between adjacent radiators 11 and reflectors 12, the distance S2 between the radiator 11 and the waveguide 13, and the distance S3 between the waveguides 13 are adjusted while performing operation confirmation.

[0042] Subsequently, the usage example of the wireless communication device 10 will be described. First, the wireless communication device 10 is installed on the object to be tracked. Also, a reader is installed at a location different from the object. As the antenna of this reader, for example, a Yagi-Uda antenna is used to give directivity. The wireless communication device 10 and the antenna are installed so as to be at height positions where they can communicate with each other. In the usage example thus configured, the reader can identify by exchanging information with the IC element 25 of the wireless communication device 10 through wireless communication. Also, it is possible to estimate the distance between them based on the intensity of the radio wave by which the reader and the wireless communication device 10 perform wireless communication. With the wireless communication device 10 of the present invention described above, it is possible to further improve the communication performance.

[0043] Next, the wireless communication devices according to the second and third embodiments of the present invention will be described with reference to Figs. 4 and 5, respectively. Note that the wireless communication devices according to the second and third embodiments are different from the wireless communication device 10 only in the configuration related to the radiator. Therefore, members having the same configuration as those of the wireless communication device 10 are denoted by the same reference numerals and the description thereof is omitted.

[0044] As shown in Fig. 4, the wireless communication device 40 according to the second embodiment is different from the wireless communication device 10 in that the radiator 11, the impedance matching unit 41 (impedance matching unit A), and the impedance matching unit 42 (impedance matching unit B) are respectively arranged on the insulating substrate 43. On this substrate 43, printed wiring is provided. Examples of this printed wiring include wiring of conductors such as those made of copper foil or gold plating. It is preferably made of gold plating, and more preferably flash gold plating in order to prevent deterioration over time due to oxidation of the substrate surface.

[0045] Here, the radiator 11 has both ends thereof mounted and fixed to the substrate 43 by, for example, a U-shaped fixing bracket 45 so as to maintain the contact state with a radiator contact pattern 44 which is a printed wiring made of copper foil formed on the substrate 43. Note that in order to further improve the contact property with the radiator contact pattern 44, it is preferable to solder the radiator 11 to the radiator contact pattern 44. In this case, the material of the radiator 11 is preferably made of brass or the like which is a solderable material.

[0046] The impedance matching unit 41 has a conductor part 46 (conductor part A) arranged in parallel with the radiator 11 and a matching adjustment part 47 (matching adjustment part A) connecting the radiator 11 and the conductor part 46. The impedance matching unit 42 has a conductor part 48 (conductor part B) arranged in parallel with the radiator 11 and a matching adjustment part 49 (matching adjustment part B) connecting the radiator 11 and the conductor part 48. The conductor part 46 and the conductor part 48 are in an insulated state and are connected via a sheet-like wiring base material 26 on which the IC element 25 is mounted.

[0047] Here, the conductor part 46 and the conductor part 48 are printed wirings made of copper foil formed on the substrate 43 and are formed in parallel with the radiator 11 (radiator contact pattern 44). The conductor part 46 and the sheet-like wiring base material 26 are connected via a separately provided connection auxiliary conductor part 50, and the conductor part 48 and the sheet-like wiring base material 26 are connected via a separately provided connection auxiliary conductor part 51. The connection auxiliary conductor part 50 and the connection auxiliary conductor part 51 are in an insulated state, but without using these, the lengths of the conductor part 46 and the conductor part 48 may be adjusted and their other ends may be directly connected to the sheet-like wiring base material 26.

[0048] Further, since the matching adjustment units 47 and 49 are each composed of a bar-shaped conductor, the distance between the opposing bars can be adjusted, enabling impedance adjustment. Here, after impedance adjustment, it is preferable to connect the matching adjustment unit 47 to the radiator 11 and the conductor unit 46 by soldering or the like, and to connect the matching adjustment unit 49 to the radiator 11 and the conductor unit 48 by soldering or the like. Furthermore, based on the specifications after impedance adjustment, the matching adjustment unit can also be composed of printed wiring formed on a substrate. Thereby, the configuration can be simplified and the manufacturing cost can be reduced.

[0049] As shown in FIG. 5, the wireless communication device 60 according to the third embodiment is different from the wireless communication device 10 in that the impedance matching unit 61 (impedance matching unit A) and the impedance matching unit 62 (impedance matching unit B) have the wire materials 63 and 64 of the conductor.

[0050] The wire materials of the wireless communication device 60 are, for example, made of copper with a diameter of 0.8 mm and a total length of 81.5 mm (= λ / 4). Both ends thereof are wound around (wrapping margin: 12 mm on one side) to positions 20 mm from the center position in the longitudinal direction of the radiator 11 to both sides thereof and connected. Also, the center in the longitudinal direction of the wire material is cut to form the wire materials 63 and 64, and the other ends are made in an insulated state and connected by the sheet-like wiring base material 26 on which the IC element 25 is mounted. The impedance matching unit 61 and the impedance matching unit 62 have a configuration in which the above-described conductor unit and the matching adjustment unit are integrated, and the shape at the time of attachment to the radiator 11 is, for example, an elliptical arc shape or a semi-circular shape, etc., and not all of the regions corresponding to the conductor unit are parallel to the radiator 11.

[0051] In the above configuration, a wireless communication device using only the radiator 11 to which the impedance matching unit 61 and the impedance matching unit 62 are connected was used. With the communication distance from the antenna (reader) set to 50 cm, the received radio wave intensity was measured. This antenna is composed of three elements (one radiator, one reflector, and one director), and is provided with a feeding line. As a result, a received radio wave intensity of -53 dBm to -55 dBm was obtained, confirming that it is a good value. In addition, for further improvement of the radio wave intensity, for example, it is preferable to adjust the length of the wire, the connection position of the impedance matching unit to the radiator, the length of the radiator, etc.

[0052] Subsequently, the wireless communication function of the wireless communication device to which the present invention is applied will be described with reference to FIGS. 6(a) to 6(c). Since the wireless communication functions of the wireless communication devices in the above-described embodiments are the same, in FIGS. 6(a) to 6(c), the wireless communication device 10 of the first embodiment described above will be used for explanation. Also, in FIGS. 6(a) to 6(c), for convenience of explanation, only the radiator 11, the reflector 12, and the director 13 of the wireless communication device 10 are illustrated. First, the wireless communication device 10 can correspond to the inclination of the wireless communication device 10 or the antenna 100. Hereinafter, this point will be described.

[0053] When the polarization characteristic of the radiator 11 is horizontal polarization, as shown in FIG. 6(a), in the wireless communication device 10 including the reflector 12 and the director 13 extending in the horizontal direction, if the polarization directions match between the wireless communication device 10 and the antenna 100, the IC element (unique information) can be surely detected. However, as shown in FIG. 6(b), when the wireless communication device 10 and the antenna 100 are relatively inclined in the rotation direction around the pointing direction D, the polarization direction is shifted between the wireless communication device 10 and the antenna 100, and the communication distance gradually becomes shorter. Depending on the relative inclination between the wireless communication device 10 and the antenna 100 in this way, there is a possibility that the IC element may not be detected.

[0054] Therefore, as shown in FIG. 6(c), the radiator 11, the reflector 12, and the waveguide 13 are arranged so as to cross each other, that is, the radiator 11, the reflector 12, and the waveguide 13 are arranged to extend in four directions perpendicular to the pointing direction D. Even when arranging them to cross each other, the radiator 11, the reflector 12, and the waveguide 13 are arranged parallel to each other. That is, a configuration having two sets of the radiator 11, the reflector 12, and the waveguide 13 as one set becomes a wireless communication device. By forming a cross antenna in this way, even if the wireless communication device 10 and the antenna 100 are relatively inclined in the rotational direction about the pointing direction D (for example, even if the antenna 100 is inclined as shown in FIG. 6(c)), that is, even if the polarization direction is shifted between the wireless communication device 10 and the antenna 100, the IC element can be surely detected.

[0055] FIG. 7 shows a configuration example in which the radiator 11, the reflector 12, and the waveguide 13 are arranged to cross each other, taking the wireless communication device 10 as an example. The radiator 11 (round bar 15) is disposed so as to penetrate the left and right side surfaces of the support 14a, and the radiator 11 (round bar 15) is also disposed so as to penetrate the upper and lower surfaces of the support 14a (the same applies to the round bar 16 of the reflector 12 and the round bar 17 of the waveguide 13). The crossing positions are preferably the same position in the pointing direction D, but as shown in FIG. 7, as long as it is a range that can be regarded as substantially the same position, there may be a slight deviation in the pointing direction D. This is because if the mutual intervals of the radiator 11, the reflector 12, and the waveguide 13 do not change, there is no influence on the communication distance.

[0056] With the above-described configuration, it is possible to cope with circular polarization, which was difficult in a two-dimensional structure, and to cope with the inclination of the wireless communication device 10 and the antenna 100. That is, in an environment where the inclination of the wireless communication device 10 or the antenna 100 fluctuates, a cross antenna may be formed as described in FIG. 6(c).

Example

[0057] Next, the analysis results obtained to confirm the effects of the present invention will be described. Here, the performance of the wireless communication device of the first embodiment described above was investigated. The specific conditions are as follows. · The wireless communication device is composed of three elements (one radiator, one reflector, and one waveguide). · Configuration of the radiator: A round bar made of aluminum alloy with a diameter of 4 mm · Length of the radiator: 146 mm, length of the reflector: 154 mm, length of the waveguide: 140 mm · Distance between the radiator and the reflector: 70 mm, distance between the radiator and the waveguide: 67 mm · Diameter of the conductor part of the impedance matching part: 0.5 mm · Length of the matching adjustment part of the impedance matching part (corresponding to the distance between the radiator and the conductor part): 7.5 mm · Total length of the paired conductor parts of the impedance matching part (corresponding to the length at the center in the length direction of the radiator): 20 mm

[0058] As a result, the feed point input impedance (Zi) was 46.3 + j119 Ω, the VSWR (Voltage Standing Wave Ratio) was 1.50, and the gain was 7.34 dBd. For reference, in the wireless communication device described in Japanese Patent Application Laid-Open No. 2019-16855, the gain was 3.40 dBd for the three-element case and 5.35 dBd for the four-element case.

[0059] From the above, it was confirmed that the wireless communication device of the present invention can achieve a higher gain than before and improve the communication performance of the antenna.

[0060] As described above, the present invention has been described with reference to the embodiments. However, the present invention is not limited to the configurations described in the above embodiments at all, and includes other embodiments and modifications conceivable within the scope of the matters described in the claims. For example, when configuring the wireless communication device of the present invention by combining some or all of the above-described embodiments and modifications, it is also included in the scope of the rights of the present invention.

Industrial Applicability

[0061] Since the present invention can provide a wireless communication device capable of improving communication performance, it is industrially useful.

Explanation of Signs

[0062] 10: Wireless communication device, 11: Radiator, 12: Reflector, 13: Waveguide, 14, 14a: Support, 15 - 17: Round bar, 18: Impedance matching unit (Impedance matching unit A), 19: Impedance matching unit (Impedance matching unit B), 20: Conductor part (Conductor part A), 21: Matching adjustment part (Matching adjustment part A), 22: Conductor part (Conductor part B), 23: Matching adjustment part (Matching adjustment part B), 24: Gap, 25: IC element, 26: Sheet-like wiring base material, 27: Holding means, 28: Support base, 29: Holding means, 30: Support base, 31: Holding means, 32: Support base, 40: Wireless communication device, 41: Impedance matching unit (Impedance matching unit A), 42: Impedance matching unit (Impedance matching unit B), 43: Substrate, 44: Pattern for radiator contact, 45: Fixing metal fitting, 46: Conductor part (Conductor part A), 47: Matching adjustment part (Matching adjustment part A), 48: Conductor part (Conductor part B), 49: Matching adjustment part (Matching adjustment part B), 50, 51: Auxiliary conductor part for connection, 60: Wireless communication device, 61: Impedance matching unit (Impedance matching unit A), 62: Impedance matching unit (Impedance matching unit B), 63, 64: Wire, 100: Antenna

Claims

1. A wireless communication device of a non-powered line type having a radiator, one end of a pair of impedance matching parts A and B is connected to both sides of the radiator apart from the longitudinal center, and the other ends of the impedance matching parts A and B are insulated by forming a gap of 100 μm or more and 3 mm or less or by arranging an insulating material, and are connected via an IC element having unique information recorded thereon; The antenna further includes a reflector disposed parallel to one side of the radiator and a director disposed parallel to the other side of the radiator, A wireless communication device (excluding wireless communication devices for microwaveable food packages) characterized in that the directors are arranged in parallel.

2. the impedance matching section A has a conductor section A arranged in parallel to the radiator, and a matching adjustment section A connecting the radiator and the conductor section A, the impedance matching section B has a conductor section B arranged in parallel with the radiator, and a matching adjustment section B connecting the radiator and the conductor section B, 2. The wireless communication device according to claim 1, wherein the conductor portion A and the conductor portion B are in the insulated state and connected via the IC element.

3. the radiator, the impedance matching section A, and the impedance matching section B are each disposed on an insulating substrate; 3. The wireless communication device according to claim 2, wherein the conductor portion A and the conductor portion B are printed wiring formed on the substrate.

4. A wireless communication device of a non-powered line type having a radiator, one end of a pair of impedance matching parts A and B is connected to both sides of the radiator apart from the longitudinal center, and the other ends of the impedance matching parts A and B are insulated by forming a gap of 100 μm or more and 3 mm or less or by arranging an insulating material, and are connected via an IC element having unique information recorded thereon; The antenna further includes a reflector disposed parallel to one side of the radiator and a director disposed parallel to the other side of the radiator, the impedance matching section A has a conductor section A arranged in parallel to the radiator, and a matching adjustment section A connecting the radiator and the conductor section A, the impedance matching section B has a conductor section B arranged in parallel with the radiator, and a matching adjustment section B connecting the radiator and the conductor section B, the conductor portion A and the conductor portion B are in the insulated state and connected via the IC element, the radiator, the impedance matching section A, and the impedance matching section B are each disposed on an insulating substrate; A wireless communication device (excluding wireless communication devices for microwave-compatible food packages) characterized in that the conductor portion A and the conductor portion B are printed wiring formed on the substrate, and the matching adjustment portion A and the matching adjustment portion B are printed wiring formed on the substrate.

5. A wireless communication device of a non-powered wire type having a radiator, One end of a pair of impedance matching units A and B is connected to both sides of the radiator except for the central portion in the longitudinal direction, and the other ends of the impedance matching units A and B are insulated by forming a gap or arranging an insulating material, and are connected via an IC element having unique information recorded thereon; the impedance matching section A has a conductor section A arranged in parallel to the radiator, and a matching adjustment section A connecting the radiator and the conductor section A, the impedance matching section B has a conductor section B arranged in parallel with the radiator, and a matching adjustment section B connecting the radiator and the conductor section B, the conductor portion A and the conductor portion B are in the insulated state and connected via the IC element, A wireless communication device, characterized in that the matching adjustment unit A and the matching adjustment unit B are conductive rods, and the distance between the opposing rods is adjustable.

6. A wireless communication device of a non-powered line type having a radiator, one end of a pair of impedance matching parts A and B is connected to both sides of the radiator apart from the longitudinal center, and the other ends of the impedance matching parts A and B are insulated by forming a gap of 100 μm or more and 3 mm or less or by arranging an insulating material, and are connected via an IC element having unique information recorded thereon; The antenna further includes a reflector disposed parallel to one side of the radiator and a director disposed parallel to the other side of the radiator, A wireless communication device (excluding wireless communication devices for microwaveable food packages) characterized in that the impedance matching section A and the impedance matching section B have conductive wires.

7. A wireless communication device of a non-powered wire type having a radiator, One end of a pair of impedance matching units A and B is connected to both sides of the radiator except for the central portion in the longitudinal direction, and the other ends of the impedance matching units A and B are insulated by forming a gap or arranging an insulating material, and are connected via an IC element having unique information recorded thereon; The antenna further includes a reflector disposed parallel to one side of the radiator and a director disposed parallel to the other side of the radiator, A wireless communication device, characterized in that the impedance matching section A and the impedance matching section B are arranged at an angle with respect to the axis of the radiator.

8. 8. The wireless communication device according to claim 7, wherein the impedance matching section A and the impedance matching section B are arranged at an inclination within a range of more than 0 degrees and less than or equal to 120 degrees from the director side to the reflector side.

9. 9. The wireless communication device according to claim 8, wherein the impedance matching section A and the impedance matching section B are disposed at an angle of 90 degrees.

10. 10. The wireless communication device according to claim 4, wherein the director is a plurality of directors arranged in parallel.

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