Wireless communication device

Abstract

This wireless communication device is provided with: a base material provided with a surrounding surface; an antenna conductor having a first end portion and a second end portion and provided on the base material so as to extend along the encircling surface; and an RFIC chip that is provided on the base material and performs wireless communication using the antenna conductor. The first end portion and the second end portion of the antenna conductor face each other at a distance from each other in the circumferential direction of the surrounding surface. The antenna conductor includes a slit extending in a circumferential direction from a first end portion toward a second end portion.

Description

Technical Field

[0001] This disclosure relates to wireless communication devices. Background Technology

[0002] For example, Patent Document 1 discloses a strip-shaped wireless communication device equipped with a dipole antenna. In the wireless communication device described in Patent Document 1, dipole antennas are provided on the strip-shaped sheet member, extending from the RFIC chip located at the central portion along the long side of the sheet member toward the outer end along the long side of the sheet member.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2023 / 276583 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] Furthermore, in recent years, there has been a demand for wireless communication devices capable of transmitting wirelessly at substantially the same communication distance in any direction within 360 degrees. Therefore, it was considered to modify the strip-shaped wireless communication device with a dipole antenna described in Patent Document 1 into a cylindrical shape. However, when the wireless communication device described in Patent Document 1 is modified into a cylindrical shape, the two ends of the dipole antenna, which are the points of maximum voltage, approach each other, resulting in a large capacitance between the two ends. Therefore, when the wireless communication device described in Patent Document 1 is modified into a cylindrical shape, the communication distance becomes extremely short compared to before modification, meaning that wireless communication at a practical distance is impossible.

[0008] Therefore, the subject of this disclosure is to perform wireless communication in a wireless communication device with substantially the same communication distance in any direction of 360 degrees.

[0009] Solution for solving the problem

[0010] To address the aforementioned technical challenges, according to one aspect of this disclosure, a wireless communication device is provided, comprising: a substrate having a surrounding surface; an antenna conductor having a first end and a second end disposed on the substrate such that it extends along the surrounding surface; and an RFIC chip disposed on the substrate, which performs wireless communication using the antenna conductor, wherein the first end and the second end of the antenna conductor are spaced apart from each other in the circumferential direction of the surrounding surface, and the antenna conductor has a slit extending circumferentially from the first end toward the second end.

[0011] The effects of the invention

[0012] According to this disclosure, in a wireless communication device, wireless communication can be performed in any direction of 360 degrees with substantially the same communication distance. Attached Figure Description

[0013] Figure 1 This is a perspective view of a wireless communication device according to Embodiment 1 of this disclosure.

[0014] Figure 2 These are perspective views of the wireless communication device of Implementation Method 1, observed from different viewpoints.

[0015] Figure 3 This is a perspective view of the base module in the wireless communication device according to Embodiment 1.

[0016] Figure 4 This is a top view of the base module in the wireless communication device of Embodiment 1.

[0017] Figure 5 This is a 3D view of the RFIC module.

[0018] Figure 6 This is a top view of the RFIC module.

[0019] Figure 7 This is an exploded 3D view of the RFIC module.

[0020] Figure 8 It is a graph showing the relationship between the communication direction and communication distance of wireless communication devices.

[0021] Figure 9 This is a perspective view of the base module in a comparative example wireless communication device.

[0022] Figure 10 This is a perspective view of the base module in the wireless communication device according to Embodiment 2.

[0023] Figure 11 This is a perspective view of the base module in the wireless communication device according to embodiment 3.

[0024] Figure 12 This is a perspective view of the base module in the wireless communication device according to embodiment 4.

[0025] Figure 13 This is a perspective view of the wireless communication device according to embodiment 5.

[0026] Figure 14 This is a top view of the base module in the wireless communication device of embodiment 5.

[0027] Figure 15 This is a perspective view of the wireless communication device according to embodiment 6.

[0028] Figure 16This is a top view of the base module in the wireless communication device of embodiment 6. Detailed Implementation

[0029] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0030] (Implementation Method 1)

[0031] Figure 1 as well as Figure 2 These are perspective views of the wireless communication device of Embodiment 1 of this disclosure, viewed from different directions.

[0032] like Figure 1 as well as Figure 2 As shown, the wireless communication device 10 of this embodiment 1 is cylindrical. Specifically, the wireless communication device 10 includes: a cylindrical substrate 12 having a surrounding surface 12a; an antenna conductor 14 disposed on the substrate 12; and an RFIC (Radio Frequency integrated circuit) chip 16 disposed on the substrate 12, which performs wireless communication using the antenna conductor 14. The cylindrical substrate 12 is, for example, a cylindrical cap having an opening 12b at one end. Furthermore, Figure 1 as well as Figure 2 Arrow R in the figure indicates the circumferential direction of the surrounding surface 12a of the substrate 12. In addition, axis C is the central axis of the cylindrical substrate 12.

[0033] In this embodiment 1, the wireless communication device 10 is manufactured by deforming a strip-shaped base module 20 containing an antenna conductor 14 and an RFIC chip 16 into a cylindrical shape and placing the cylindrical base module 20 on a substrate 12.

[0034] Figure 3 This is a 3D view of the base module. Additionally, Figure 4 This is a top view of the base module. Furthermore, the XYZ orthogonal coordinate system in the figure is used to facilitate understanding of this disclosure and does not limit this disclosure. The X-axis direction represents the long side direction of the base module, the Y-axis represents the short side direction (width direction), and the Z-axis direction represents the thickness direction.

[0035] like Figure 3 as well as Figure 4 As shown, the base module 20 has a strip-shaped sheet member 22, an antenna conductor 14 disposed on the sheet member 22, and an RFIC chip 16 disposed on the sheet member 22.

[0036] In this embodiment 1, the sheet member 22 of the base module 20 is rectangular, and is made of resins such as PPS, PET, and PP. Figure 1 as well as Figure 2As shown, the sheet member 22 is disposed on the substrate 12 in a deformed cylindrical state. Specifically, the cylindrical sheet member 22 is disposed on the substrate 12 such that its long side direction (X-axis direction) is substantially parallel to the circumferential direction R of the surrounding surface 12a of the substrate 12, and its width direction (Y-axis direction) is substantially parallel to the central axis C of the substrate 12. Therefore, for example, the sheet member 22 is adhered to the outer or inner surface of the cylindrical substrate 12. In addition, for example, the sheet member 22, maintained in a cylindrical state, is inserted into the substrate 12.

[0037] In this embodiment 1, the antenna conductor 14 on the sheet member 22 is rectangular, for example, a conductor pattern made of a conductive material such as aluminum. The antenna conductor 14 extends along the long side direction (X-axis direction) of the sheet member 22 and has a first end 14a and a second end 14b.

[0038] like Figure 1 as well as Figure 2 As shown, when the cylindrical sheet member 22 is disposed on the substrate 12, the antenna conductor 14 extends along the surrounding surface 12a of the substrate 12. For example, the antenna conductor 14 extends in the circumferential direction R with an extension length of more than 3 / 4 of the surrounding length of the surrounding surface 12a. Additionally, as... Figure 2 As shown, the first end 14a and the second end 14b of the antenna conductor 14 are positioned opposite each other at a distance D in the circumferential direction R of the surrounding surface 12a. Further details regarding the distance D will be described later.

[0039] like Figure 3 as well as Figure 4 As shown, the antenna conductor 14 has a slit 14c. Furthermore, the term "slit" as used in this specification refers to a notch that starts from the outer periphery of the antenna conductor 14, extends substantially along the long side direction (X-axis direction) of the antenna conductor 14 (i.e., the circumferential R of the surrounding surface 12a of the substrate 12), and whose terminal is not connected to the outer periphery (the terminal is located inside the outer periphery).

[0040] like Figure 3 as well as Figure 4 As shown, the slit 14c is formed on the antenna conductor 14 in such a way that it starts from the first end 14a and extends toward the second end 14b along the long side direction (X-axis direction) (i.e., the circumferential R of the surrounding surface 12a of the substrate 12). Specifically, in the case of this embodiment 1, the antenna conductor 14 is rectangular, so its first end 14a and second end 14b respectively include a first end edge 14d and a second end edge 14e extending along a direction intersecting the circumferential R of the surrounding surface 12a of the substrate 12 (i.e., the width direction (Y-axis direction) of the base module 20). The slit 14c starts from the first end edge 14d of the first end 14a and extends toward the second end edge 14e of the second end 14b along the long side direction, terminating near the second end edge 14e.

[0041] Furthermore, in this embodiment 1, the slit 14c extends in a meandering manner with a substantially constant width. The reason for the meandering extension of the slit 14c will be explained later.

[0042] In this embodiment 1, the antenna conductor 14 is magnetically coupled to the RFIC chip 16. Therefore, the RFIC chip 16 is modular.

[0043] Figure 5 This is a 3D view of the RFIC module. Additionally, Figure 6 This is a top view of the RFIC module. Furthermore, Figure 7 This is an exploded 3D view of the RFIC module.

[0044] like Figures 5-7 As shown, in this embodiment 1, the RFIC chip 16 is modularized. That is, the RFIC chip 16 is assembled in the RFIC module 30. The RFIC module 30 has a chip member 32, an RFIC chip 16 disposed on the chip member 32, and a coil conductor 34 electrically connected to the RFIC chip 16.

[0045] The sheet member 32 is rectangular and made of insulating material. Additionally, the sheet member 32 has a first surface 32a and a second surface 32b that is the opposite side to the first surface 32a.

[0046] The RFIC chip 16 has a first terminal 16a and a second terminal 16b that are electrically connected to the coil conductor 34.

[0047] In this embodiment 1, the RFIC chip 16 is disposed on the first surface 32a of the wafer member 32. Specifically, firstly, a first connecting pad conductor 36 electrically connected to one end of the coil conductor 34 and a second connecting pad conductor 38 electrically connected to the other end of the coil conductor 34 are disposed on the first surface 32a of the wafer member 32. These first connecting pad conductors 36 and second connecting pad conductors 38 are, for example, conductor patterns.

[0048] The first terminal 16a of the RFIC chip 16 is electrically connected to and fixed relative to the first connector conductor 36, for example via soldering material. The second terminal 16b of the RFIC chip 16 is electrically connected to and fixed relative to the second connector conductor 38, for example via soldering material.

[0049] The coil conductor 34 is magnetically coupled to the antenna conductor 14 of the base module 20.

[0050] In this embodiment 1, the coil conductor 34 includes a first helical conductor 40 disposed on a first surface 32a of the sheet member 32 and a second helical conductor 42 disposed on a second surface 32b of the sheet member 32. When viewed from above (along the Z-axis), the first helical conductor 40 and the second helical conductor 42 partially overlap each other. These first helical conductors 40 and second helical conductors 42 are, for example, conductor patterns.

[0051] In addition, in the case of this embodiment 1, the coil conductor 34 includes an interlayer connecting conductor 44 such as a through-hole conductor that passes through the sheet member 32 in the thickness direction (Z-axis direction) and electrically connects one end 40a of the first helical conductor 40 to one end 42a of the second helical conductor 42.

[0052] like Figure 6 As shown, when viewed from above (along the Z-axis), the sheet component 32 has an RFIC chip 16, a first connecting disk conductor 36, and a second connecting disk conductor 38 arranged in the opening 34a of the coil conductor 34.

[0053] To electrically connect the other end 40b of the first helical conductor 40 in the coil conductor 34 to the first connecting disc conductor 36, the first connecting conductor 46 is disposed on the first surface 32a of the sheet member 32. The first connecting conductor 46 is, for example, a conductor pattern.

[0054] In addition, in order to electrically connect the other end 42b of the second helical conductor 42 in the coil conductor 34 to the second connecting disk conductor 38, the second connecting conductor 48 is disposed on the second surface 32b of the sheet member 32. The second connecting conductor 48 is, for example, a conductor pattern. The second connecting conductor 48 is electrically connected to the second connecting disk conductor 38 via an interlayer connecting conductor 50, such as a through-hole conductor penetrating the sheet member 32.

[0055] In order to couple with the magnetic field of the coil conductor 34 in such an RFIC module 30, such as Figure 3 as well as Figure 4 As shown, the antenna conductor 14 has an opening 14f. In this embodiment 1, the RFIC module 30 is, for example, attached to the portion of the sheet member 22 exposed through the opening 14f of the antenna conductor 14 by an insulating adhesive. The opening 14f is formed on the antenna conductor 14 to the size and shape of the rectangular sheet member 32 that surrounds the RFIC module 30 at intervals. That is, the opening edge of the opening 14f surrounds the coil conductor 34 of the RFIC module 30 at intervals.

[0056] According to such a wireless communication device 10 (i.e., base module 20), when a signal (radio wave) is received, current flows through the antenna conductor 14. The current flowing along the opening edge of the opening 14f generates a magnetic field passing through the opening 14f. This magnetic field induces a current in the coil conductor 34 of the RFIC module 30. The RFIC chip 16 operates by receiving this current supply, supplying a current corresponding to a transmit signal in response to the received signal to the coil conductor 34. Upon receiving this current supply, the coil conductor 34 generates a magnetic field corresponding to the transmit signal. Through this magnetic field, a current corresponding to the transmit signal flows through the antenna conductor 14, and the antenna conductor 14 emits a transmit signal (radio wave) in response to the received signal.

[0057] In the case of this embodiment 1, such as Figure 1 as well as Figure 2 As shown, the antenna conductor 14 extends along the surrounding surface 12a of the substrate 12. As a result, the wireless communication device 10 is able to perform wireless communication at substantially the same communication distance in any normal direction of the surrounding surface 12a.

[0058] Figure 8 This is a graph showing the relationship between the communication direction and communication distance of wireless communication devices. Furthermore, Figure 8 The communication direction and communication distance are shown when viewed from the extension direction of the central axis C of the cylindrical substrate 12. Additionally, Figure 8 The direction where the angle is zero is the direction in which the RFIC module 30 exists.

[0059] like Figure 8 As shown, regarding the angular direction (0 degrees) and its opposite angular direction (180 degrees) of the RFIC module 30, although the communication distance is slightly shorter compared to other angular directions, there is no angular direction with an extremely short communication distance. Therefore, the wireless communication device 10 of this embodiment 1 can perform wireless communication with substantially the same communication distance in any normal direction of the surrounding surface 12a of the substrate 12. The reason for this will be explained by comparative examples.

[0060] Figure 9 This is a perspective view of the base module in a comparative example wireless communication device.

[0061] like Figure 9 As shown, the comparative example base module 120, like that of Embodiment 1, includes a strip-shaped sheet member 122, an antenna conductor 114 disposed on the sheet member 122, and an RFIC chip 16 disposed on the sheet member 122 and using the antenna conductor 114 for wireless communication. In the case of the comparative example base module 120, the antenna conductor 114 is a dipole antenna extending from the RFIC chip 16 disposed at the central portion of the strip-shaped sheet member 122 in the long side direction (X-axis direction) toward the outer end of the sheet member 122 in the long side direction.

[0062] exist Figure 9 In the case of the base module 120 of the comparative example shown, if radio waves are received, current flows from the first end 114a of the dipole antenna-shaped antenna conductor 114 toward the second end 114b or vice versa. That is, the first end 114a and the second end 114b become the points of maximum voltage.

[0063] If the base module 120 of this comparative example is cylindrical with the first end 114a and the second end 114b spaced apart, a large capacitance is generated between the first end 114a and the second end 114b. For example, if the potential of the first end 114a is set to +V and the potential of the second end 114b is set to -V, a potential difference Δ2V is generated between these ends 114a and 114b, forming a large capacitance between them. As a result, the current flowing through the antenna conductor 114 is consumed by the capacitance, and the communication distance of the antenna conductor 114 is drastically reduced compared to before it was cylindrical.

[0064] In contrast, in the case of this embodiment 1, such as Figure 4 As shown, the first end 14a of the antenna conductor 14 is divided into two parts 14g and 14h by a slit 14c. In this case of the antenna conductor 14, when a radio wave is received, current flows from one part 14g of the first end 14a towards the other part 14h, or vice versa. Specifically, current flows from one part 14g along the slit 14c towards the second end 14b, then back from the second end 14b, and flows from the second end 14b along the slit 14c towards the other part 14h. That is, currents flow in opposite directions on the two opposite sides of the antenna conductor 14 separated by the slit 14c. Furthermore, the parts 14g and 14h in the first end 14a become points of maximum voltage.

[0065] If the base module 20 of this embodiment 1 is cylindrical and the first end 14a and the second end 14b are spaced apart and opposite each other, unlike the comparative example, no large capacitance is generated between them. For example, if the potential of one part of the first end 14a is set to +V and the potential of the other part is set to -V, the potential of the second end 14b is approximately zero. Thus, the potential difference between the spaced-apart first end 14a and second end 14b is ΔV. As a result, a smaller capacitance is formed between the first end 14a and the second end 14b of the antenna conductor 14 than in the comparative example. As a result, the communication distance of the antenna conductor 114 of this embodiment 1 is not drastically reduced compared to before it was cylindrical, and remains substantially the same in any normal direction of the surrounding surface 12a of the substrate 12.

[0066] A capacitance is also generated between the two opposite portions of the antenna conductor 14, separated by slit 14c. However, this capacitance is used to achieve impedance matching between the antenna conductor 14 and the RFIC chip 16, i.e., to match the resonant frequency with the communication frequency. Furthermore, for this impedance matching, the extension length of slit 14c is adjusted to a predetermined extension length corresponding to the resonant frequency. By making the slit 14c of the predetermined extension length meandering, the size of the antenna conductor 14, i.e., the size of the base module 20, is made more compact compared to the straight-line case.

[0067] In addition, such as Figure 2 As shown, by making the base module 20 cylindrical, the distance D between the first end 14a and the second end 14b, which are opposite each other in the circumferential direction R, is preferably larger than the width W of the slit 14c. If, unlike this, the distance D is smaller than the width W, the impedance matching between the antenna conductor 14 and the RFIC chip 16 is affected, and the resonant frequency changes. That is, similar to the capacitance between the two ends of the antenna conductor 14 opposite each other across the slit 14c, the capacitance between the first end 14a and the second end 14b participates more significantly in impedance matching.

[0068] According to this embodiment 1 as described above, the wireless communication device 10 can perform wireless communication in any direction of 360 degrees with substantially the same communication distance.

[0069] (Implementation Method 2)

[0070] This second embodiment is an improvement upon the first embodiment described above. Therefore, this second embodiment will be described focusing on the differences from the first embodiment. Furthermore, structural elements that are substantially the same as those in the wireless communication device 10 of the first embodiment will be labeled with the same reference numerals.

[0071] Figure 10 This is a perspective view of the base module in the wireless communication device according to Embodiment 2.

[0072] like Figure 10 As shown, the base module 220 in the wireless communication device of this embodiment 2, which is deformed into a cylindrical shape along the surrounding surface of the cylindrical substrate, has a rectangular antenna conductor 214 extending along the long side direction (X-axis direction) of the base module 220. The antenna conductor 214 has a meandering slit 214c extending from a first end 214a toward a second end 214b.

[0073] Specifically, the first end 214a and the second end 214b of the antenna conductor 214 include a first end edge 214d and a second end edge 214e extending in a direction intersecting the circumferential direction of the surrounding surface of the substrate (i.e., the width direction (Y-axis direction) of the base module 220). Additionally, it includes two side edges 214j and 214k extending circumferentially from both ends of the first end edge 214d (i.e., the long side direction (X-axis direction) of the base module 220) and connecting to both ends of the second end edge 214e. A slit 214c begins near the first end edge 214d of one of the side edges 214j of the first end 214a and extends circumferentially toward the second end 214b.

[0074] The wireless communication device of this embodiment 2 is similar to the wireless communication device 10 of embodiment 1 described above, and can perform wireless communication in any direction of 360 degrees with substantially the same communication distance.

[0075] (Implementation Method 3)

[0076] In the case of the above-described embodiment 1, such as Figure 3 as well as Figure 4 As shown, an RFIC chip 16 (i.e., RFIC module 30) is disposed near the center of the slit 14c of the antenna conductor 14. In contrast, in this embodiment 3, the RFIC chip is disposed inside the end of the slit. Therefore, this embodiment 3 will be described with this difference in mind. In addition, structural elements that are substantially the same as the structural elements of the wireless communication device 10 in embodiment 1 described above are labeled with the same reference numerals.

[0077] Figure 11 This is a perspective view of the base module in the wireless communication device according to embodiment 3.

[0078] like Figure 11 As shown, the base module 320 in the wireless communication device of this embodiment 3, which is deformed into a cylindrical shape along the surrounding surface of the cylindrical substrate, has an antenna conductor 314 extending along the long side direction (X-axis direction) of the base module 320. The antenna conductor 314 has a meandering slit 314c extending from a first end 314a toward a second end 314b.

[0079] Additionally, the RFIC module 30, which includes the RFIC chip, is disposed within the terminal of the slit 314c located at the second end 314b. Thus, the coil conductor within the RFIC module 30 (refer to...) Figure 5 The magnetic field is partially coupled to the terminal of the slit 314c surrounding the antenna conductor 314.

[0080] The wireless communication device of this embodiment 3 is similar to the wireless communication device 10 of embodiment 1 described above, and can perform wireless communication in any direction of 360 degrees with substantially the same communication distance.

[0081] (Implementation Method 4)

[0082] In the case of the above-described implementation method 1, such as Figure 4 As shown, the slit 14c of the antenna conductor 14 extends from the first end 14a towards the second end 14b without making a U-turn. In contrast, the slit in this embodiment 4 makes a U-turn. Therefore, this embodiment 4 will be described with this difference as the focus. In addition, structural elements that are substantially the same as the structural elements of the wireless communication device 10 of the above embodiment 1 are labeled with the same reference numerals.

[0083] Figure 12 This is a perspective view of the base module in the wireless communication device according to embodiment 4.

[0084] like Figure 12 As shown, the base module 420 in the wireless communication device of this embodiment 4, which is deformed into a cylindrical shape along the surrounding surface of a cylindrical substrate, has an antenna conductor 414 extending along the long side direction (X-axis direction) of the base module 420. The antenna conductor 414 has a slit 414c extending from a first end 414a toward a second end 414b. Furthermore, the slit 414c extends in a manner that makes a U-shaped turn at the second end 414b and returns to the first end 414a. Moreover, the slit 414c terminates midway toward the first end 414a. That is, the slit 414c is approximately "J"-shaped. Furthermore, in the case of this embodiment 4, the slit 414c has a shape in which its width gradually decreases as it moves toward the terminal.

[0085] Additionally, the RFIC module 30, containing the RFIC chip, is disposed within the terminal of the slit 414c. Thus, the coil conductor within the RFIC module 30 (refer to...) Figure 5 The magnetic field is partially coupled to the end of the slit 414c surrounding the antenna conductor 414.

[0086] The wireless communication device of this embodiment 4 is similar to the wireless communication device 10 of embodiment 1 described above, and can perform wireless communication with substantially the same communication distance in any direction of 360 degrees.

[0087] (Implementation Method 5)

[0088] In the case of the above-described implementation method 1, such as Figure 2As shown, by making the base module 20 cylindrical, the gap D between the first end 14a and the second end 14b, which are opposite each other in the circumferential direction R, is set to a size that will not form a large capacitance therebetween. However, when the gap D widens, the communication distance of the wireless communication device 10 in the normal direction of the portion of the sheet member 22 located between the first end 14a and the second end 14b is reduced compared to other directions, eventually resulting in a null point where communication is impossible. The wireless communication device of this embodiment 5 has a structure that suppresses the generation of such null points.

[0089] Figure 13 This is a perspective view of the wireless communication device according to Embodiment 5. Additionally, Figure 14 This is a top view of the base module in the wireless communication device of embodiment 5.

[0090] like Figure 13 as well as Figure 14 As shown, the base module 520 of the wireless communication device 510 of this embodiment 5 has a strip-shaped sheet member 522, an antenna conductor 514 disposed on the sheet member 522, and an RFIC module 30 disposed on the sheet member 522.

[0091] Antenna conductor 514 extends along the long side (X-axis direction) of sheet member 522 and has a first end 514a and a second end 514b. For example... Figure 13 As shown, when the cylindrical sheet member 522 is disposed on the substrate 512, the first end 514a and the second end 514b are spaced apart and opposite each other in the circumferential direction R.

[0092] Additionally, the antenna conductor 514 includes a slit 514c, which is formed to extend from a first end 514a toward a second end 514b along the long side direction (X-axis direction) (i.e., the circumferential R of the surrounding surface 512a of the substrate 512). A portion of the slit 514c is enlarged, and an RFIC module 30 is disposed in this enlarged portion.

[0093] Furthermore, the first end 514a and the second end 514b of the antenna conductor 514 respectively include a first end edge 514d and a second end edge 514e. In this embodiment 5, the first end edge 514d and the second end edge 514e respectively have the same... Figure 2 as well as Figure 4The first edge 14d and the second edge 14e of the antenna conductor 14 in Embodiment 1 shown above have different shapes. Specifically, in Embodiment 5, the first edge 514d and the second edge 514e of the antenna conductor 514 are not straight, but have portions that are close to each other in the circumferential direction R at a distance D2 and portions that are far apart in the circumferential direction R at a distance D1 greater than the distance D2. As a result, the first end 514a and the second end 514b can be close to each other in the circumferential direction R to a degree that can suppress the generation of null points. Since the length (length in the width direction (Y-axis direction) of the base module 520) of the portions that are close to each other at a distance D2 (in the case of Embodiment 5) is short, the increase in capacitance between the first end 514a and the second end 514b caused by this closeness is suppressed. That is, even if the first end 514a and the second end 514b are close enough to suppress the generation of null points, they can be separated by a distance D1 by a portion of each of them (in the case of embodiment 5, the central portion) so that the capacitance between the first end 514a and the second end 514b is suppressed to be small (compared to the case where the first end edge 514d and the second end edge 514e are straight).

[0094] Furthermore, in this embodiment 5, in the antenna conductor 514, the first end edge 514d of the first end 514a and the second end edge 514e of the second end 514b are respectively as follows: Figure 14 As shown, both the first end edge 514d and the second end edge 514e are concave when viewed from the thickness direction (Z-axis direction) of the base module 520. However, the shapes of the first end edge 514d and the second end edge 514e are not limited to concave. For example, either the first end edge 514d or the second end edge 514e may be straight, and the other may be convex.

[0095] Furthermore, in the case of embodiment 5, such as Figure 14 As shown, the antenna conductor 514 in slit 514c has two end branches on the first end 514a side. One first slit branch 514i is connected to the end edge 514d. The other second slit branch 514j is not connected to the outer periphery of the antenna conductor 514, but terminates at a predetermined length. The function of this second slit branch 514j will be explained.

[0096] like Figure 14As shown, the first end 514a of the antenna conductor 514 is separated into two parts 514g and 514h by a slit 514c. When the wireless communication device 510 transmits and receives radio waves, current flows from one part 514g along the slit 514c toward the second end 514b, then turns back at the second end 514b, and flows from the second end 514b along the slit 514c toward the other part 514h. The second slit branch 514j serves to make the first electrical length between one part 514g of the first end 514a and the second end 514b, and the second electrical length between the other part 514h of the first end 514a and the second end 514b, equal. That is, the second electrical length is adjusted by adjusting the length of the second slit branch 514j, thereby making the second electrical length close to the first electrical length. In the case of this embodiment 5, by adjusting the length of the second slit branch 514j to a predetermined length, the first electrical length and the second electrical length are made approximately equal. Therefore, the communication distance on one side of the central axis C of the cylindrical substrate 512 of the wireless communication device 510 is approximately equal to the communication distance on the other side.

[0097] (Implementation Method 6)

[0098] The wireless communication device of this embodiment 6 is a variation of the wireless communication device of embodiment 5 described above, configured such that when viewed in the extension direction of the central axis of the wireless communication device, the communication distance is further equal in any of the 360-degree directions.

[0099] Figure 15 This is a perspective view of the wireless communication device according to Embodiment 6. Additionally, Figure 16 This is a top view of the base module in the wireless communication device of embodiment 6.

[0100] like Figure 15 as well as Figure 16 As shown, the base module 620 of the wireless communication device 610 of this embodiment 6 has a strip-shaped sheet member 622, an antenna conductor 614 disposed on the sheet member 622, and an RFIC module 30 disposed on the sheet member 622.

[0101] Antenna conductor 614 extends along the long side (X-axis direction) of sheet member 622 and has a first end 614a and a second end 614b. For example... Figure 15 As shown, when the cylindrical sheet member 622 is disposed on the substrate 612, the first end 614a and the second end 614b are spaced apart and opposite each other in the circumferential direction R.

[0102] Additionally, the antenna conductor 614 has a meandering slit 614c, which is formed to extend from the first end 614a toward the second end 614b along the long side direction (X-axis direction) (i.e., the circumferential R of the surrounding surface 612a of the substrate 612). A portion of the slit 614c is enlarged, and an RFIC module 30 is disposed in this enlarged portion.

[0103] In this embodiment 6, unlike embodiment 5 described above, the base module 620 has a sub-antenna conductor 652. For example... Figure 16 As shown, the sub-antenna conductor 652 extends along the long side (X-axis direction) of the sheet member 622 along the antenna conductor 614. Furthermore, the sub-antenna conductor 652 extends from the first end 614a of the antenna conductor 614 in the direction (X-axis direction) toward the second end 614b of the antenna conductor 614. In this embodiment 6, the antenna conductor 614 and the sub-antenna conductor 652 are integrated into a single conductor pattern.

[0104] Based on this sub-antenna conductor 652, the directional nature of the communication range of the wireless communication device 610 is essentially eliminated when viewed in the direction of extension of the central axis C. That is, when viewed in the direction of extension of the central axis C, the communication range is substantially equal in any of the 360-degree directions.

[0105] In addition, such as Figure 15 as well as Figure 16 As shown, in the wireless communication device 610 of this embodiment 6, two sub-antenna conductors 652 are disposed on the sheet member 622 such that an antenna conductor 614 is spaced between them. However, the sub-antenna conductor 652 may be any single one.

[0106] The present disclosure has been described above with examples of several embodiments, but the embodiments of the present disclosure are not limited thereto. For example, in embodiment 1, the chip member 32 of the RFIC module 30 and the chip member 22 of the base module 20 are made independent, but coil conductors 34 and the like can also be provided on the surface and back of the chip member 22, and the RFIC module 30 and the base module 20 can be integrated by mounting the RFIC chip 16.

[0107] Furthermore, in the case of the above-described embodiment 1, such as Figure 3 as well as Figure 4As shown, the antenna conductor 14 and the RFIC chip 16 are magnetically coupled via the coil conductor 34. However, embodiments of this disclosure are not limited to this. For example, the RFIC chip may be configured to span the slit of the antenna conductor, or a lead-out electrode portion may be formed on the slit electrode of the antenna conductor. Specifically, the first terminal and the second terminal of the RFIC chip are fixed to the two banks of the slit or the lead-out electrode ends via soldering or the like. Thus, the RFIC chip is directly connected to the antenna conductor.

[0108] Furthermore, for impedance matching, the RFIC chip and antenna conductor can also be connected via a coil conductor (inductor). For example, an RFIC module can be fabricated comprising an RFIC chip, a first coil conductor connected at one end to a first terminal of the RFIC chip and at the other end to the antenna conductor, and a second coil conductor connected at one end to a second terminal of the RFIC chip and at the other end to the antenna conductor. This RFIC module is then positioned across the antenna conductor in a slot-like manner. Compared to a direct connection between the RFIC chip and antenna conductor without a coil conductor (inductor), this allows for miniaturization of the base module. Furthermore, without a coil conductor, it is necessary to increase the size of the antenna conductor (i.e., increase the antenna length) to match the impedance between the RFIC chip and the antenna conductor.

[0109] That is, the various methods of this disclosure are as follows.

[0110] The first approach is a wireless communication device comprising: a substrate having a surrounding surface; an antenna conductor having a first end and a second end disposed on the substrate such that it extends along the surrounding surface; and an RFIC chip disposed on the substrate, which performs wireless communication using the antenna conductor, wherein the first end and the second end of the antenna conductor are spaced apart from each other in the circumferential direction of the surrounding surface, and the antenna conductor has a slit extending circumferentially from the first end toward the second end.

[0111] The second approach, based on the wireless communication device of the first approach, includes a first end edge extending in a direction intersecting the circumferential direction at the first end of the antenna conductor, and the slit extending circumferentially from the first end edge at the first end toward the second end.

[0112] The third approach, based on the wireless communication device of the second approach, includes a second end edge extending along a direction intersecting the circumferential direction at the second end of the antenna conductor. The first end edge of the first end and the second end edge of the second end respectively have portions that are close to each other in the circumferential direction and portions that are far apart from each other in the circumferential direction.

[0113] The fourth method is based on the wireless communication device of the second method, wherein the slit branches at the first end into a first slit branch and a second slit branch, the first slit branch is connected to the first end edge of the first end, and the second slit branch terminates at a predetermined length.

[0114] The fifth method, based on the wireless communication device of the first method, includes a first end edge extending in a direction intersecting the circumferential direction and two side edges extending in the circumferential direction from both ends of the first end edge, and the slit starting from a portion near the first end edge of one of the side edges of the first end edge and extending in the circumferential direction toward the second end edge.

[0115] The sixth method, based on any of the first to fifth methods of wireless communication devices, wherein the circumferential interval between the first end and the second end is larger than the width of the slit at the first end.

[0116] The seventh method is based on the wireless communication device of any of the first to sixth methods, wherein the antenna conductor extends along the circumferential direction with an extension length of more than 3 / 4 of the circumferential length of the surrounding surface.

[0117] The eighth method is based on the wireless communication device of any of the first to seventh methods, wherein the slit is meandering.

[0118] The ninth method is based on any of the first to eighth methods of a wireless communication device, wherein the wireless communication device has an RFIC module, the RFIC module includes the RFIC chip and a coil conductor electrically connected to the RFIC chip, the antenna conductor has an opening that communicates with the slit and is defined by an opening edge that surrounds the coil conductor of the RFIC module at intervals, and the coil conductor is magnetically coupled to the opening edge of the opening in the antenna conductor.

[0119] The tenth method, based on any of the first to ninth methods of wireless communication devices, further includes a strip-shaped sheet member on which the antenna conductor and the RFIC chip are disposed, the sheet member being disposed on the substrate in a deformed cylindrical state.

Claims

1. A wireless communication device, wherein, The wireless communication device has: The substrate has a surrounding surface; An antenna conductor having a first end and a second end, disposed on the substrate such that it extends along the surrounding surface; as well as An RFIC chip, disposed on the substrate, uses the antenna conductor for wireless communication. The first end and the second end of the antenna conductor are spaced apart and opposite each other in the circumferential direction of the surrounding surface. The antenna conductor has a slit that starts from the first end and extends circumferentially toward the second end.

2. The wireless communication device according to claim 1, wherein, The first end of the antenna conductor includes a first end edge extending in a direction intersecting the circumferential direction. The slit begins at the first edge of the first end and extends circumferentially toward the second end.

3. The wireless communication device according to claim 2, wherein, The second end of the antenna conductor includes a second end edge extending in a direction intersecting the circumferential direction. The first edge of the first end and the second edge of the second end each have portions that are close to each other in the circumferential direction and portions that are far apart from each other in the circumferential direction.

4. The wireless communication device according to claim 2, wherein, The slit branches at the first end into a first slit branch and a second slit branch. The first slit branch is connected to the first end edge of the first end. The second slit branch terminates at a predetermined length.

5. The wireless communication device according to claim 1, wherein, The first end of the antenna conductor includes a first end edge extending in a direction intersecting the circumferential direction, and two side edges extending in the circumferential direction from both ends of the first end edge. The slit begins near the first end edge of one of the side edges of the first end and extends circumferentially toward the second end.

6. The wireless communication device according to any one of claims 1 to 5, wherein, The wireless communication device also has a secondary antenna conductor that extends from the first end of the antenna conductor and along the antenna conductor in a direction toward the second end.

7. The wireless communication device according to any one of claims 1 to 6, wherein, The circumferential interval between the first end and the second end is greater than the width of the slit at the first end.

8. The wireless communication device according to any one of claims 1 to 7, wherein, The antenna conductor extends circumferentially with an extension length of more than 3 / 4 of the circumferential length of the surrounding surface.

9. The wireless communication device according to any one of claims 1 to 8, wherein, The slit is meandering.

10. The wireless communication device according to any one of claims 1 to 9, wherein, The wireless communication device has an RFIC module, which includes the RFIC chip and a coil conductor electrically connected to the RFIC chip. The antenna conductor has an opening that communicates with the slit and is defined by an opening edge that surrounds the coil conductor of the RFIC module at intervals. The coil conductor is magnetically coupled to the opening edge of the opening in the antenna conductor.

11. The wireless communication device according to any one of claims 1 to 10, wherein, The wireless communication device also has a strip-shaped sheet member on which the antenna conductor and the RFIC chip are disposed, the sheet member being disposed on the substrate in a deformed cylindrical state.

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