Multi-resonance antenna

Abstract

The present invention discloses a multi-resonant antenna comprising a main antenna and an additional radiating element. The main antenna comprises a main portion forming an open loop and a feed portion diverging from the main portion. The additional radiating element extends from the main antenna toward the exterior of the main antenna. The multi-resonant antenna of the present invention has a structure capable of resonating at multiple operating frequencies.

Description

Technical Field

[0001] The present invention relates to a multi-resonance antenna. Background Art

[0002] Japanese Patent No. 6020451 (Patent Document 1) discloses a small broadband antenna 900. Figure 8 As shown, antenna 900 of Patent Document 1 includes a split ring resonator 910 using a split ring 920, which is a ring-shaped conductor having a slit portion 922. Specifically, antenna 900 of Patent Document 1 includes a main body 930 and a feeder 940, with main body 930 forming split ring 920. Here, feeder 940 is provided for main body 930.

[0003] The antenna 900 of Patent Document 1 operates at the resonant frequency of the split ring resonator 910. In other words, the antenna 900 of Patent Document 1 resonates only at one operating frequency and cannot cope with a wide frequency band. Summary of the Invention

[0004] An object of the present invention is to provide an antenna having a structure capable of generating resonance at multiple operating frequencies.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] In one aspect, the present invention provides a multi-resonance antenna comprising a main antenna and an additional radiating element. The main antenna comprises a main portion forming an open loop and a feed portion diverging from the main portion. The additional radiating element extends from the main antenna toward the exterior of the main antenna.

[0007] In addition to the main antenna, the multi-resonant antenna also includes an additional radiating element. This structure allows the multi-resonant antenna of the present invention to resonate at both the operating frequency of the first resonant section and the operating frequency of the second resonant section. In other words, the multi-resonant antenna of the present invention has a structure capable of resonating at multiple operating frequencies. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 FIG2 is a plan view of a multi-resonance antenna according to an embodiment of the present invention, wherein the antenna assembly mounted on the circuit board and its vicinity are shown in an enlarged scale.

[0009] Figure 2 is included in Figure 1 A plan view of a circuit board in a multi-resonant antenna is shown. The mounting area and its vicinity, on which the antenna assembly is mounted, are shown on an enlarged scale.

[0010] Figure 3 is included in Figure 1 A perspective view of an antenna assembly in a multi-resonance antenna is shown.

[0011] Figure 4 yes Figure 1 A schematic diagram of a first variation of a multi-resonance antenna is shown.

[0012] Figure 5 yes Figure 1 FIG. 4 is a schematic diagram of a second variation of a multi-resonant antenna.

[0013] Figure 6 yes Figure 1 A schematic diagram of a third variation of a multi-resonance antenna is shown.

[0014] Figure 7 yes Figure 1 FIG. 4 is a schematic diagram of a fourth variation of a multi-resonance antenna.

[0015] Figure 8 This is a plan view of the antenna disclosed in Patent Document 1. DETAILED DESCRIPTION

[0016] like Figure 1 As shown, the multi-resonance antenna 10 of the embodiment of the present invention is provided with a circuit board (substrate) 20 and an antenna assembly 32. In this embodiment, the antenna assembly 32 partially forms the main antenna 30.

[0017] like Figure 2 As shown, the circuit board 20 of this embodiment has a conductive pattern (pattern) 200. Conductive pattern 200 includes a feed portion 210, a ground pattern (ground portion) 220, and an additional radiating element 230. Furthermore, conductive pattern 200 includes a first main portion 252 that partially forms the main antenna 30. The first main portion 252 is located in a mounting area 250 where the antenna assembly 32 is mounted. The first main portion 252 has a pattern shape determined based on the desired antenna characteristics. The first main portion 252, together with the antenna assembly 32 mounted on the circuit board 20, forms the main antenna 30. Thus, the multi-resonant antenna 10 of this embodiment includes the main antenna 30 and the additional radiating element 230.

[0018] from Figure 1 and Figure 2 It can be understood that the antenna assembly 32 of this embodiment is formed from a metal member, which is mounted on the circuit board 20 when in use. In other words, the antenna assembly 32 is a discrete component that is mounted on the circuit board 20 when in use. However, the present invention is not limited to this. The antenna assembly 32 of the present invention can be formed using other methods, such as plating a resin body with a metal film or attaching a metal member to the resin body.

[0019] from Figure 1 and Figure 2It can be understood that in this embodiment, the main antenna 30 is formed by the antenna component 32 and a portion (the first main body portion 252) of the conductive pattern 200 of the circuit board 20. However, the present invention is not limited to this. The main antenna 30 may be formed only by the antenna component 32. Alternatively, the main antenna 30 may be formed by one or more conductive layers included in the circuit board 20. For example, the main antenna 30 may be formed by using a multilayer wiring substrate as the circuit board 20 and using multiple conductive layers and multiple through-holes included in the multilayer wiring substrate.

[0020] refer to Figure 3 The antenna assembly 32 of this embodiment includes a second main portion 320, a feed leg portion 340, and a facing portion 350. The antenna assembly 32 also includes multiple grounding portions 370 and multiple fixing portions 380. The second main portion 320, together with the first main portion 252 of the circuit board 20, forms the main portion of the main antenna 30. In other words, in this embodiment, the main portion of the main antenna 30 is formed by the first main portion 252 of the circuit board 20 and the second main portion 320 of the antenna assembly 32.

[0021] like Figure 3 As shown, the second main body 320 of this embodiment is shaped like a substantially rectangular ring that is long in the transverse direction. However, the present invention is not limited thereto. The second main body 320 of the present invention can have various ring shapes, for example, not only a substantially rectangular ring, but also a circular, elliptical, and polygonal ring. In this embodiment, the transverse direction is the X direction. Specifically, in this embodiment, the negative X direction is also referred to as the first predetermined direction.

[0022] like Figure 3 As shown, the second body portion 320 has a first end portion 322 and a second end portion 324. The first end portion 322 and the second end portion 324 are separated and opposed to each other to form a split portion 326. In other words, the second body portion 320 forms an open ring having the split portion 326.

[0023] like Figure 3 As shown, the feed leg portion 340 diverges from the second main body portion 320. In the present embodiment, the feed leg portion 340 diverges from the second main body portion 320 at a position closer to the first end portion 322 than the second end portion 324. The feed leg portion 340 extends rearward and then downward. When the main antenna 30 is mounted on the circuit board 20, the feed leg portion 340 is connected to the feed portion 210. In the present embodiment, the front-to-back direction is the Y direction. The positive Y direction points forward, while the negative Y direction points rearward. Specifically, in the present embodiment, the positive Y direction is also referred to as the second predetermined direction. In addition, in the present embodiment, the up-down direction is the Z direction. The positive Z direction points upward, while the negative Z direction points downward.

[0024] like Figure 3As shown, the facing portion 350 includes a first facing portion 352 and a second facing portion 354. The first facing portion 352 and the second facing portion 354 are spaced apart and opposed to each other to form a capacitor. The first facing portion 352 and the second facing portion 354 are provided to the first end 322 and the second end 324 of the second main body 320, respectively. In this embodiment, the first end 322 and the first facing portion 352 are integrally formed. Similarly, the second end 324 and the second facing portion 354 are integrally formed.

[0025] like Figure 3 As shown, the first facing portion 352 has a first upper facing portion 362 extending downward from the first end portion 322, and a first lower facing portion 364 extending forward, then downward, and further rearward from the first end portion 322. Furthermore, the second facing portion 354 has a second upper facing portion 366 extending rearward from the second end portion 324, and a second lower facing portion 368 extending forward, then downward, and further rearward from the second end portion 324. However, the present invention is not limited thereto. In the present invention, assuming that the first facing portion 352 and the second facing portion 354 are formed into a capacitor having desired characteristics, their shapes and sizes are not particularly limited.

[0026] from Figure 3 As can be seen, the second main portion 320, due to its shape, forms the inductive element of the main antenna 30. The first end portion 322 and the second end portion 324, together with the first and second facing portions 352 and 354, form the capacitive component of the main antenna 30. This structure enables the main antenna 30 to operate as an LC resonant circuit (first resonant component). The LC resonant circuit formed by the main antenna 30 is also known as a split-ring resonator. Therefore, the main antenna 30 forms the first resonant component.

[0027] Reference again Figure 2 The feed section 210, ground pattern 220, additional radiating element 230, and first main body 252 formed on the circuit board 20 are formed using a single conductive layer (conductive pattern 200). Furthermore, the feed section 210, ground pattern 220, additional radiating element 230, and first main body 252 are adjacent to each other. However, the present invention is not limited thereto. The feed section 210, ground pattern 220, additional radiating element 230, and first main body 252 can be formed using conductive layers and through-holes included in a multilayer wiring substrate.

[0028] like Figure 2 As shown, in this embodiment, the conductive pattern 200 covers the surface of the circuit board 20 except for a predetermined area. The feeding portion 210 is formed in the slit 222 formed in the conductive pattern 200. The feeding portion 210 extends in the front-rear direction.

[0029] from Figure 1To understand, the additional radiating element 230 extends outward from the main antenna 30. In detail, as Figure 2 As shown, the additional radiating element 230 extends from the first main portion 252 toward the exterior of the main antenna 30. In this embodiment, the additional radiating element 230 includes a base portion 232 extending from the first main portion 252 in the second predetermined direction (positive Y direction), and a first extension portion 234 extending from the base portion 232 in the first predetermined direction (negative X direction). However, the present invention is not limited thereto. If the additional radiating element 230 extends from the first main portion 252 in the first predetermined direction, the additional radiating element 230 may not include the base portion 232. Furthermore, the additional radiating element 230 may extend from the feed portion 210 toward the exterior of the main antenna 30. In this case, the base portion 232 may not have a linear shape, but may have a curved shape. Furthermore, the first extension portion 234 of the additional radiating element 230 may have a wide portion at its tip.

[0030] like Figure 1 As shown, in plan view, the additional radiating element 230 extends from the first end 322 of the antenna assembly 32 and near the feed leg portion 340. Furthermore, in plan view, the additional radiating element 230 does not overlap with the ground pattern 220. The additional radiating element 230 forms at least a portion of a second resonant portion that is different from the first resonant portion. Specifically, the additional radiating element 230, alone or in conjunction with a portion of the conductive pattern 200, forms the second resonant portion.

[0031] like Figure 1 and 2 As shown, a gap region 240 is formed between the first extension portion 234 of the additional radiating element 230 and the ground pattern 220. The size of the gap region 240 is determined in consideration of the characteristics of the main antenna 30 and the characteristics of the additional radiating element 230.

[0032] like Figure 2 As shown, the ground pattern 220 has a second extension portion 224 and a third extension portion 226 that partially define a void area 240. The second extension portion 224 is away from the first extension portion 234 of the additional radiating element 230 in the front-to-rear direction and extends from the vicinity of the mounting area 250 in the first predetermined direction. The third extension portion 226 extends from the second extension portion 224 in the second predetermined direction.

[0033] like Figure 1 and Figure 2 As shown, in this embodiment, the tip of the first extension portion 234 of the additional radiation element 230 is away from and toward the third extension portion 226 in the first predetermined direction.

[0034] The electrical length of the additional radiating element 230 is determined based on one quarter of the length of the desired operating frequency. The desired operating frequency is different from the operating frequency of the main antenna 30.

[0035] In the multi-resonance antenna 10 formed as described above, the first resonant section and the second resonant section have different operating frequencies. In other words, the multi-resonance antenna 10 of this embodiment can resonate at the operating frequency of the main antenna 30 and the operating frequency of the additional radiating element 230. The first resonant section is connected to a resonant source (not shown) via the feed section 210. The second resonant section is connected to the first resonant section. Thus, the multi-resonance antenna 10 has a structure capable of resonating at multiple operating frequencies.

[0036] In more detail, the multi-resonant antenna 10 of this embodiment has a structure capable of generating electrical resonance at two operating frequencies, one of which is the operating frequency of the LC resonant circuit operating as the main antenna 30, and the other is the operating frequency of the additional radiating element 230 depending on the electrical length of the additional radiating element 230.

[0037] The embodiment of the present invention has been described so far, and the embodiment can be modified as follows.

[0038] (Variation 1)

[0039] like Figure 4 As shown, the first modified multi-resonance antenna 10A includes a main antenna 30A and an additional radiating element 230A. The main antenna 30A includes a main portion 320A, a feed portion 210A, a ground line portion 342, and a facing portion 350A. The multi-resonance antenna 10A also includes a substrate (not shown).

[0040] from Figure 4 It can be understood that in the first variant of the multi-resonant antenna 10A, the main antenna 30A and the additional radiating element 230A are integrally formed. For example, when used, the combination of the main antenna 30A and the additional radiating element 230A can be formed by a metal member mounted on a substrate (not shown). Alternatively, the combination of the main antenna 30A and the additional radiating element 230A can be formed by one or more conductive patterns (patterns) formed on or in the substrate. Conversely, a portion of the combination of the main antenna 30A and the additional radiating element 230A can be formed by one or more conductive patterns formed on or in the substrate, and the remaining portion of the combination of the main antenna 30A and the additional radiating element 230A can be formed by a metal member different and separate from the substrate.

[0041] like Figure 4As shown, the main body 320A includes a first portion 330, a second portion 332, a third portion 334, a fourth portion 336, and a fifth portion 338. The first portion 330 and the second portion 332 extend in a transverse direction. The first portion 330 and the second portion 332 are arranged along a first predetermined direction. The fourth portion 336 extends in a transverse direction. The fourth portion 336 is spaced apart from the first portion 330 and the second portion 332 in the front-to-back direction and is arranged parallel to the first portion 330 and the second portion 332. The third portion 334 and the fifth portion 338 extend in the front-to-back direction. The third portion 334 and the fifth portion 338 are arranged to be spaced apart and parallel to each other.

[0042] like Figure 4 As shown, the first portion 330 and the second portion 332 of the main body 320A have a first end 322A and a second end 324A, respectively. The first end 322A and the second end 324A are separated and opposed to each other, forming a split portion 326A. The third portion 334 of the main body 320A connects the second portion 332 with the fourth portion 336. The fifth portion 338 of the main body 320A connects the first portion 330 with the fourth portion 336. Thus, the main body 320A forms an open ring with the split portion 326A. However, the present invention is not limited to this. Assuming that the main body 320A forms an open ring, the main body 320A can have another ring shape, such as a circular or oval shape.

[0043] like Figure 4 As shown, the feed portion 210A diverges from the main portion 320A at a position closer to the first end 322A than the second end 324A. Furthermore, the additional radiating element 230A extends from the main portion 320A at another position closer to the first end 322A than the second end 324A. Specifically, both the feed portion 210A and the additional radiating element 230A diverge from the first portion 330 of the main portion 320A. In a lateral direction or a first predetermined direction, the additional radiating element 230A is further from the first end 322A than the feed portion 210A. However, the present invention is not limited thereto. Depending on the desired characteristics, the additional radiating element 230A may be located at the same position as the feed portion 210A or closer to the first end 322A than the feed portion 210A. Furthermore, depending on the desired characteristics, the additional radiating element 230A may extend from the feed portion 210A instead of from the main portion 320A.

[0044] like Figure 4As shown, the feed section 210A extends from the first portion 330 of the main body 320A toward the fourth portion 336 in the front-to-back direction. A ground pattern (not shown) is formed on the substrate (not shown), and the fourth portion 336 of the main body 320A is electrically connected to the ground pattern. Alternatively, the fourth portion 336 of the main body 320A may be part of the ground pattern. The end of the feed section 210A is connected to a feed line (not shown) or a circuit element (not shown) to serve as a driving point 40. In addition, at least one of the third portion 334 of the main body 320A, the fourth portion 336 of the main body 320A, and the fifth portion 338 of the main body 320A should be connected to the ground pattern.

[0045] like Figure 4 As shown, the additional radiating element 230A extends from the main portion 320A of the main antenna 30A toward the exterior of the main antenna 30A. Specifically, the additional radiating element 230A includes a base portion 232A extending from the first portion 330 of the main portion 320A in the second predetermined direction, and a first extension portion 234A extending from the base portion 232A in the first predetermined direction. When a substrate (not shown) includes a ground pattern (not shown), the additional radiating element 230A is formed so as not to overlap with the ground pattern in plan view. However, the present invention is not limited to this. While the additional radiating element 230A includes the first extension portion 234A, it may not include the base portion 232A. Furthermore, the shape of the first extension portion 234A is not limited to a rectangle, but may include a wide portion at its tip. The additional radiating element 230A corresponds to a quarter wavelength of the desired operating frequency.

[0046] like Figure 4 As shown, the facing portion 350A has a first facing portion 352A and a second facing portion 354A. The first facing portion 352A and the second facing portion 354A extend from the first end portion 322A and the second end portion 324A in the front-to-back direction respectively. The first facing portion 352A and the second facing portion 354A also extend toward the interior of the main body 320A. The first facing portion 352A and the second facing portion 354A are separated from each other by a predetermined distance and are arranged parallel to each other. However, the present invention is not limited to this. Assuming that the first facing portion 352A and the second facing portion 354A form a capacitor with predetermined characteristics, their shapes are not particularly limited. In addition, when the main body 320A is formed by a pattern on a substrate (not shown), the first facing portion 352A and the second facing portion 354A can be made of a metal component that is different from and separate from the substrate.

[0047] from Figure 4To understand, in the multi-resonant antenna 10A, the main antenna 30A is fed from the driving point 40. The additional radiating element 230A is connected to the main antenna 30A. With this structure, the main antenna 30A operates as an open-loop resonator (LC resonant circuit or first resonant section), and the additional radiating element 230A operates as a second resonant section different from the first resonant section. The first resonant section and the second resonant section have different resonant frequencies. Therefore, the first variant of the multi-resonant antenna 10A has a structure capable of electrically resonating at two operating frequencies: one of which is the operating frequency of the main antenna (first resonant section) 30A, and the other is the operating frequency of the additional radiating element (second resonant section).

[0048] (Transformation 2)

[0049] like Figure 5 As shown, in addition to the structure of the multi-resonance antenna 10A of the first modification, the multi-resonance antenna 10B of the second modification is further provided with a second extension portion (ground portion) 224B. Since the multi-resonance antenna 10B is identical to the multi-resonance antenna 10A of the first modification except for the second extension portion 224B, a detailed description of the structure other than the second extension portion 224B is omitted.

[0050] like Figure 5 As shown, the second extension 224B extends from one end of the fourth portion 336 of the main body 320A along a first predetermined direction. In other words, the second extension 224B is arranged parallel to the additional radiating element 230A. In the second predetermined direction, the second extension 224B is away from the additional radiating element 230A. When the main antenna 30A is made of a metal component, the second extension 224B can be integrally formed with the main antenna 30A using the metal component. Alternatively, the second extension 224B can be formed from a conductive pattern (not shown) of a substrate (not shown). Conversely, the second extension 224B can be connected to a ground pattern (not shown) of the substrate, or can be part of the ground pattern. However, in a plan view, the ground pattern is not present between the second extension 224B and the additional radiating element 230A.

[0051] from Figure 5 It can be understood that the multi-resonance antenna 10B of this modification also has a structure capable of generating resonance at two operating frequencies, one of which is the operating frequency of the main antenna (first resonant part) 30A, and the other is the operating frequency of the additional radiation element (second resonant part) 230A.

[0052] (Transformation 3)

[0053] like Figure 6As shown, in addition to the structure of the multi-resonance antenna 10B of the second modification, the multi-resonance antenna 10C of the third modification is further provided with a third extension portion (ground portion) 226C. Since the multi-resonance antenna 10C is identical to the multi-resonance antenna 10B of the second modification except for the third extension portion 226C, a detailed description of the structure other than the third extension portion 226C will be omitted.

[0054] like Figure 6 As shown, the third extension 226C extends from one end of the second extension 224B along the second predetermined direction. The third extension 226C and the additional radiating element 230A do not intersect each other. Specifically, the tip of the third extension 226C is distal to the additional radiating element 230A. In this variation, the third extension 226C does not protrude forward of the additional radiating element 230A in the front-to-back direction. However, the present invention is not limited thereto. The third extension 226C may protrude forward of the additional radiating element 230A in the front-to-back direction. Regardless, in the lateral direction or the first predetermined direction, the tip of the additional radiating element 230A is distal to the third extension 226C and faces the third extension 226C. The third extension 226C may be formed from a metal member or from a conductive pattern (not shown) on a substrate (not shown). Alternatively, the third extension 226C may be connected to a ground pattern (not shown) on the substrate or may be part of the ground pattern. However, in a plan view, no ground pattern exists between the third extension 226C and the additional radiating element 230A.

[0055] from Figure 6 It can be understood that the multi-resonant antenna 10C of this modification also has a structure capable of electrically resonating at two operating frequencies, one of which is the operating frequency of the main antenna (first resonant part) 30A, and the other is the operating frequency of the additional radiating element (second resonant part) 230A.

[0056] (Transformation 4)

[0057] like Figure 7 As shown, the multi-resonance antenna 10D of the fourth modification is provided with an additional radiating element 230D in place of the additional radiating element 230A of the multi-resonance antenna 10A of the first modification. Since the multi-resonance antenna 10D is identical to the multi-resonance antenna 10A of the first modification except for the additional radiating element 230D, a detailed description of the details other than the additional radiating element 230D will be omitted.

[0058] like Figure 7As shown, the additional radiation element 230D diverges from the second portion 332 of the main body portion 320A. The additional radiation element 230D has a base 232D and a first extension 234D, the base 232D extending from the second portion 332 of the main body portion 320A in a second predetermined direction, and the first extension 234D extending in a direction opposite to the first predetermined direction. The additional radiation element 230D is formed to correspond to a quarter wavelength of the desired operating frequency. When the substrate (not shown) has a ground pattern (not shown), the additional radiation element 230D is formed so as not to overlap with the ground pattern in a plan view. However, the present invention is not limited thereto. Assuming that the additional radiation element 230D has the first extension 234D, it may not have the base 232D. In addition, the shape of the first extension 234D is not limited to a rectangle, but may have a wide portion at its tip. In addition, Figure 7 The multi-resonance antenna 10D shown can be further increased with Figure 5 The second extension 224B shown corresponds to the extension. Figure 7 The multi-resonance antenna 10D shown can be further increased with Figure 6 The second extension 224B and the third extension 226C are shown as corresponding extensions.

[0059] from Figure 7 To understand, the multi-resonant antenna 10D of this modification also has a structure capable of generating electrical resonance at two operating frequencies, one of which is the operating frequency of the main antenna (first resonant part) 30A, and the other is the operating frequency of the additional radiating element (first resonant part) 230D.

[0060] The above are preferred embodiments of the present invention and the technical principles used therein. For those skilled in the art, any obvious changes such as equivalent transformations, simple replacements, etc. based on the technical solution of the present invention, without departing from the spirit and scope of the present invention, are within the scope of protection of the present invention.

Claims

1. A multi-resonance antenna comprising a main antenna and an additional radiating element, characterized in that: The main antenna includes a main body portion forming an open loop and a feeding portion diverging from the main body portion; The additional radiating element extends from the main antenna toward the exterior of the main antenna; The multi-resonance antenna includes a ground portion; In a plan view, the additional radiating element does not overlap with the ground portion; The additional radiation element has a first extension portion extending along a first predetermined direction; The ground portion has a second extending portion extending away from the first extending portion in a second predetermined direction perpendicular to the first predetermined direction and along the first predetermined direction; The ground portion has a third extending portion extending from the second extending portion along the second predetermined direction; The first extension portion of the additional radiating element has a tip that is away from and toward the third extension portion in the first predetermined direction; The multi-resonance antenna includes a substrate having a pattern; as well as The main body portion of the main antenna is formed by a combination of at least a portion of the pattern on the substrate and a metal member that is different and separate from the substrate.

2. The multi-resonance antenna according to claim 1, wherein: The additional radiating element extends from the main body of the main antenna.

3. The multi-resonance antenna according to claim 1, wherein: The additional radiating element is formed by at least another part of the pattern on the substrate.

4. The multi-resonance antenna according to claim 1, wherein: The main body has a first end and a second end; The feed portion diverges from the main body portion at a position closer to the first end portion than the second end portion; as well as The additional radiating element extends from the main portion at a position closer to the first end portion than the second end portion, or extends from the feeding portion.

5. The multi-resonance antenna according to claim 1, wherein: The ground portion is integrally formed with the main body of the main antenna by using a metal member.

6. The multi-resonance antenna according to claim 1, wherein: The ground portion is formed by at least a portion of the pattern formed on the substrate.

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