JP2003243919A - Small-sized antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized antenna, provided with an antenna element 14 having two meander patterns 14a, 14b whose meander directions are different, and a resin molded material 16 formed in a manner of embedding the antenna element, with a stable characteristic where deformation of the meander patterns hardly takes place at forming of the resin molded material. <P>SOLUTION: A fillet portion 12 is provided in the inside of a corner portion T<SB>1</SB>, which is easily deformed during resin molding, among corner portions of the meander patterns 14a, 14b and chamfering is eliminated to thicken the width of conductor. Since frequency variations become greater if the corner portion T<SB>2</SB>, which is similarly easily deformed, is provided with the fillet portion and the chamfering is eliminated, no fillet portion is provided to the corner portion T<SB>2</SB>but the chamfering only is omitted, and the corner portion T<SB>3</SB>adjacent to the corner portion T<SB>2</SB>is provided with the fillet portion 12 and the chamfering is eliminated. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a small antenna in which an antenna element having a meandering pattern in at least a part thereof and a resin molded body are integrated.

[0002]

2. Description of the Related Art For a small antenna in which an antenna element and a resin molded body are integrated, the antenna element is set in a cavity of a mold and resin is injection molded.
It is manufactured by so-called insert molding (see, for example, Patent Document 1). The antenna element has a meander pattern punched or etched from a thin metal plate (the conductor becomes a narrow strip shape) (may be all meander patterns or some may be meander patterns) ), When the small antenna is manufactured by the above method, the meander pattern is likely to be deformed due to the flow of resin during injection molding.

Therefore, conventionally, when forming an antenna element, when the antenna element and a wide frame provided on the outside thereof are formed as an integral conductor pattern that is connected by a number of connecting portions, and injection molding is performed. The frame and the connecting portion are sandwiched between molds and held so that the meander pattern is not deformed.

[0004]

[Patent Document 1] Japanese Patent Laid-Open No. 10-209745

[0005]

However, if the meander pattern becomes complicated, there is a portion where the meander pattern and the frame cannot be connected by the connecting portion, and deformation easily occurs at this portion.

Further, in the case of an antenna element having a meander pattern, it is advantageous to chamfer the outside of the corner part of the meander pattern in order to widen the band. However, chamfering the outside of the corner reduces the mechanical strength of the corner,
This also causes a deformation of the meander pattern during injection molding.

In order to prevent the deformation of the meander pattern, it is effective to widen the band-shaped conductor or thicken it, but if this is done, the resonance frequency will increase, which is not preferable.

In view of the above problems, it is an object of the present invention to provide a small antenna with stable antenna characteristics in which the meander pattern is unlikely to be deformed when a resin molded body is molded.

[0009]

Means for Solving the Problems To achieve this object, the present invention provides a small-sized antenna provided with an antenna element having a meander pattern of a band-shaped conductor and a resin molded body formed integrally with the antenna element. In the antenna, a fillet portion is provided inside the corner portion of the meander pattern, which is easily deformed during resin molding.

As used herein, the “fillet portion” is as shown in FIG.
As shown in (A), (B), or (C), at a corner portion T where the strip-shaped conductor 10 bends, it refers to a portion 12 that extends inward from a portion where straight line inner sides of the strip-shaped conductor 10 intersect. Providing such fillet portions 12 reinforces the corner portions, so that the corner portions are less likely to be deformed during resin molding. Further, when the fillet portion 12 is provided, the conductor width in that portion is widened, but since the conductor width is locally widened, an increase in the resonance frequency can be suppressed.

The resin is likely to be deformed at the corners where the outer frame-side connecting part of the meander pattern is not near, so that the fillet is preferably provided at such corners. .

Further, when the antenna element has a plurality of meander patterns having different meander traveling directions, the corner portion where the meander traveling direction changes cannot generally be provided with a connecting portion with the frame in the vicinity.
The fillet portion is preferably provided at such a corner portion because it is easily deformed during resin molding.

Further, in the case of an antenna element having a meander pattern, it is preferable that the corner portion of the meander pattern is chamfered on the outside as described above, but the corner portion provided with the fillet portion is not chamfered on the outside. Preferably. This is because it is preferable to omit chamfering and further reinforce the corner portion that is provided with the fillet portion for reinforcement.

Furthermore, when one of the two corners forming one U-turn is easily deformed during resin molding, the corner closer to the center (center of length) of the antenna element is It is preferable to omit chamfering without providing a fillet portion, and to provide a fillet portion at a corner farther from the center to omit chamfering. This is because if the corner portion closer to the center of the antenna element is thickened, the frequency variation becomes large.

Further, in the small antenna of the present invention, the antenna elements are arranged so that the meandering pitch directions of the first meandering pattern and the second meandering pattern are different, and the first meandering pattern is It has a corner near the gate where the resin is injected during resin molding and a corner far away from the gate. It is preferable that the meat portion is provided.

That is, the small antenna according to claim 1 is
A small antenna provided with an antenna element (14) having a meander pattern of a band-shaped conductor and a resin molded body (16) molded so as to be integrated with the antenna element, wherein a resin molding is performed in a corner portion of the meander pattern. Inside the corners, which tend to be deformed, the fillet (1
2) is provided.

The small antenna according to claim 2 is the small antenna according to claim 1, wherein the fillet portion (12) is a connecting portion (26) with the outer frame (24) of the meander pattern.
Is provided in a corner portion (T1) which is not nearby.

The small antenna according to claim 3 is the small antenna according to claim 1, wherein the antenna element (14) has a plurality of meander patterns (14a, 14b) having different meander traveling directions, The flesh portion (12) is characterized in that it is provided at the corner portion (T1) where the meandering traveling direction changes.

The small antenna according to claim 4 is the small antenna according to claim 1, wherein most of the corner portions of the meander pattern are chamfered on the outside, and the fillet portion (12) is formed. The corner portion (T1) provided is characterized in that the outside is not chamfered.

The small antenna according to claim 5 is the small antenna according to claim 4, wherein one corner portion (T2) of the two corner portions (T2, T3) constituting one U-turn portion is If the antenna element (14) is easily deformed during resin molding, the corner (T2) closer to the center of the antenna element (14) is chamfered without a fillet, and the corner (T3) farther from the center is a corner. A feature is that a meat part (12) is provided and chamfering is omitted.

A small antenna according to claim 6 is the small antenna according to claim 1, wherein the antenna elements have different meander traveling directions, and the first meander pattern (14
a) and the second meander pattern (14b) are arranged so that the pitch directions of the meanders are orthogonal to each other, and the first meander pattern has a corner portion near a gate into which resin is injected during resin molding. And a corner portion at a position apart from each other, and a corner portion at a position adjacent to a corner portion at a close position is provided with a fillet portion (12).

The small antenna according to claim 7 is an antenna element (1
4) and a resin molded body (16) molded so as to be integrated with this antenna element, in a small antenna, inside at least one of the plurality of corners of the antenna element (14). It is characterized in that a fillet portion (12) is provided in the.

By thus forming the fillet portions at the corners of the antenna element, it is possible to reinforce the predetermined corners.

A small antenna according to claim 8 is the small antenna according to claim 7, wherein the antenna element (14) has a chamfered corner portion (T).
4) and a corner portion (T1) in which the chamfering on the outside is omitted and the fillet portion (12) is provided.

In this way, while providing the corner by chamfering the outside to widen the band, the chamfering on the outside is omitted and the corner is provided to improve the strength, thereby providing a wider band and injection. It is possible to achieve both prevention of deformation during molding.

A small antenna according to claim 9 is the small antenna according to claim 7 or 8, wherein a plurality of corner portions of the antenna element (14) are chamfered on the outside or outside. The chamfer is omitted and the fillet portion (12) is provided at any one of the corner portions (T1).

[0027] Normally, it is desirable that the corner portion for which the strength is required to be improved is limited, so that the corner is not chamfered, the fillet portion is provided, and the other corner portions are chamfered to widen the band.

The small antenna according to claim 10 is the small antenna according to any one of claims 7 to 9, wherein the corner portion provided with the fillet portion (12) is more easily deformed than other corner portions. It is characterized by being a part.

As described above, it is possible to effectively prevent deformation at the time of injection molding by providing a fillet portion at a corner portion that is more easily deformed than other corner portions to improve the strength.

The small antenna according to claim 11 is the small antenna according to any one of claims 7 to 9, wherein the corner portion where the fillet portion (12) is provided has a frame (24) outside the antenna element (14). ) Is a corner portion (T1) which is not near.

Since such a corner portion is easily deformed, the deformation at the time of injection molding can be effectively prevented in the case of such a configuration.

A small antenna according to claim 12 is the antenna according to any one of claims 7 to 9, wherein the fillet portion (1
A small antenna characterized in that the corner portion provided with 2) is a corner portion (T5) close to the gate (37) into which resin is injected during resin molding.

Since the corner portion near the gate is easily deformed by being exposed to high injection pressure during injection molding, when the fillet portion is provided in such a corner portion, the deformation during injection molding is effectively prevented. can do.

A small antenna according to claim 13 is the small antenna according to claims 7 to 9, wherein the antenna element (14) has a plurality of meander patterns (14a, 14b) having different meander traveling directions. The corner portion provided with the fillet portion (12) is a corner portion (T1) in which the meandering traveling direction changes.

Since it is difficult to provide a connecting portion with the outer frame and the corner portion is easily deformed, such a corner portion can effectively prevent deformation during injection molding.

A small antenna according to claim 14 is the small antenna according to any one of claims 7 to 9, wherein one U
It has two corners (T2, T3) forming a turn part, and a fillet part (12) is provided only on one of the two corners (T2, T3). .

This is because if the fillet portions 12 are provided on both of the corner portions adjacent to each other in the meander width direction, the frequency variation becomes large. This is U including these corners
It is thought that this is because the electrical length of the turn part is significantly shortened.

A small antenna according to a fifteenth aspect is the small antenna according to the fourteenth aspect, wherein a corner portion (T3) provided with a fillet portion (12) of the two corner portions (T2, T3) is It is characterized in that it is a corner portion (T3) farther from the center of the antenna element (14).

As described above, if the fillet portions 12 are provided on both of the corner portions adjacent to each other in the meander width direction as described above, the frequency variation increases, so the fillet portions 12 are provided only on one corner. This is because the frequency variation is further suppressed by setting the corner portion as a corner portion far from the center portion of the antenna element.

A small antenna according to claim 16 is the small antenna according to any one of claims 7 to 9, wherein a corner portion (T2) that is more easily deformed than other corners among the plurality of corner portions of the meander pattern. Is a resin molding (1
6) when located near the center of the resin molded body (16), the corner portion (T
At least one of the corner portions (T1, T3) connected to 2) has a fillet portion (12).

By the way, as described above, if the corner portion near the center of the antenna element is thickened, the frequency variation becomes large. Therefore, when the corner portion which is easily deformed is located near the center, the corner portion which is easily deformed is continuously provided. It is possible to achieve a good balance between the effect of suppressing the frequency fluctuation and the effect of preventing deformation by providing a fillet portion at the corner portion.

A small antenna according to claim 17 is the small antenna according to any one of claims 7 to 9, wherein the antenna element (14) has three corner portions (T1, T2, T).
3) including a crank-shaped pattern, and one corner portion (T2) of the crank-shaped pattern is located near the center of the resin molded body (16), the resin molded body (16) It is characterized in that a fillet portion (12) is provided on at least one of the corner portions (T1, T3) that are located away from the center and are connected to the corner portion (T2).

Since it is difficult to provide a connecting portion with the outer frame and the corner portion is easily deformed, in the case of such a configuration, it is possible to achieve both the prevention of deformation during injection molding and the suppression of frequency fluctuation with good balance.

A small antenna according to claim 18 is the small antenna according to any one of claims 7 to 9, wherein a corner portion (T2) near a gate (37) into which a resin is injected at the time of resin molding has a resin molded body. When it is located near the center of (16), it is located away from the center of the resin molded body (16) and is connected to the corner (T2).
1, T3) is provided with a fillet portion (12).

As described above, the corner portion close to the gate is easily exposed to high injection pressure during injection molding and is easily deformed. Therefore, in such a configuration, it is possible to prevent deformation during injection molding and suppress frequency fluctuation. You can achieve a good balance.

A small antenna according to claim 19 is the small antenna according to any one of claims 7 to 9, wherein the antenna element (14) is a first meander arranged so that pitch directions of meanders having different meander directions are orthogonal to each other. The first meander pattern (14a) has a pattern (14a) and a second meander pattern (14b), and the first meander pattern (14a) is located near the center of the resin molding (16) (T).
2) is located away from the center of the resin molding (16) and is connected to the corner (T2).
1, T3), and the corner portion (T
1, T3) is provided with a fillet portion (12).

Since such a corner portion is likely to be deformed to such a shape, it is possible to achieve both the prevention of deformation during injection molding and the suppression of frequency fluctuation in a well-balanced manner.

A small antenna according to claim 20 is the small antenna according to any one of claims 7 to 9, wherein the antenna element (14) is a first meander arranged so that pitch directions of meanders having different meander directions are orthogonal to each other. It has a pattern (14a) and a second meander pattern (14b), and the first meander pattern (14a) is close to the gate (37) into which the resin is injected at the time of resin molding and the resin molded body ( 16) a corner portion (T2) located near the center of the gate and the corner portion (T1, T2) located away from the gate (37) and connected to the corner portion (T2).
3) and has the above-mentioned connected corner portions (T1, T)
The fillet portion (12) is provided on at least one of the points 3).

Since such a corner portion is likely to be deformed, in the case of such a configuration, it is possible to achieve both the prevention of deformation during injection molding and the suppression of frequency fluctuation with good balance.

A small antenna according to a twenty-first aspect is the small antenna according to the fourteenth to seventeenth aspects, wherein the corner portion (T) is located near the center of the resin molded body (16).
2) A small antenna whose chamfer is omitted.

Since the corner portion is easily deformed as described above, the chamfering further reduces the strength. Therefore, the chamfering portion is not provided in order to suppress the frequency fluctuation, but it is desirable to omit the chamfering.

A small antenna according to claim 22 is the small antenna according to any one of claims 7 to 19, wherein the antenna element (14) is provided with a fillet portion (12) and a chamfered corner portion ( T6) is further included.

Even if the corner portion is further provided, it is possible to prevent the deformation and widen the band.

[0054]

Embodiments of the present invention will be described below.
A detailed description will be given with reference to the drawings.

FIG. 2 shows an embodiment of the present invention. In this small antenna, the antenna element 14 is composed of two meander patterns 14a and 14b having different meandering directions, and the antenna element 14 is embedded in a flat resin molding 16. A power supply terminal 18 is formed on one end side of the antenna element 14 so as to extend outside the resin molded body 12, and a fixed terminal 20 to a circuit board or the like extends outside the resin molded body 16 on the other end side. Has been formed.

Such a small antenna is manufactured as follows. First, the conductor pattern 22 as shown in FIG.
Are formed by punching or etching a thin metal plate (for example, a copper plate). This conductor pattern 22 holds an antenna element 14 composed of two meander patterns 14a and 14b having different meandering directions in a rectangular wide frame 24. The antenna element 14 is connected to the frame 24 at a number of places via connecting portions 26. Further, one end side of the antenna element 14 is connected to the frame 24 via the power supply terminal 18, and the other end side is connected to the frame 24 via the fixed terminal 20. As a result, the antenna element 14 is held at a predetermined position in the frame 24. Reference numeral 28 denotes positioning holes formed at the four corners of the frame 24.

Such a conductor pattern 22 is set in a mold and injection molding is performed. The mold is an upper mold and a lower mold in which the frame of the two-dot chain line is the cavity 30 and the parts outside the two-dot chain line (outer end side of the connecting portion 26 of the conductor pattern 22, terminals 18, 20
The outer end side and the frame 24) are sandwiched. The gate 37 for injecting the resin into the cavity 30 is provided on the surface 30a of the cavity 30 on the fixed terminal 20 side of the antenna element 14. After injection molding with such a die, the connecting portion 26 is cut along the peripheral surface of the resin molded body, and the power supply terminal 18 and the fixed terminal 20 are cut while leaving an appropriate length. Such a small antenna can be obtained.

Antenna element of this small antenna
14 is composed of two meander patterns 14a and 14b having different meander traveling directions, and the meander pattern is complicated. When the meander pattern is complicated in this way, a corner portion where the connecting portion 26 cannot be formed is formed. For example, corner portions T1 and T2. Such corners T1 and T2 are easily deformed by the flow of resin during resin molding. The corner portion T4 on the inner side of the second meander pattern 14b is also a corner portion where a connecting portion cannot be formed. However, since the meander width of the second meander pattern 14b is narrow, deformation does not easily occur, and there is no problem as it is.

Further, in the case of an antenna element having a meander pattern, it is preferable to provide the chamfered portion 32 on the outer side of all the corner portions as shown in FIG. 4 in order to widen the band. However, providing the chamfered portions 32 at the corner portions T1 and T2, which are easily deformed during resin molding, lowers the mechanical strength of those portions and results in promoting deformation.

Therefore, in this embodiment, the corner portion T
1 That is, in the corner portion where the meandering direction of the meander pattern changes, a fillet portion 12 is provided on the inner side, chamfering to be provided on the outer side is omitted, and the conductor width is locally thickened to improve the mechanical strength. It is intended. In addition, the corner portion T5 shown in FIG.
Since it is close to 7, it is easily deformed, and if the fillet portion 12 is provided here, the strength can be improved. The corner portion near the gate 37 is easily deformed because the resin injection pressure at the time of injection molding is high near the gate, as described above.

Here, the corner portion T2 shown in FIG. 3 is also desired to have a structure similar to that of the corner portion T5 shown in FIG. 5 if the mechanical strength is emphasized. However, the corner portions T2 shown in FIG. Providing the section 12 may increase the frequency variation, which is not preferable in some cases. this is,
It is considered that the electric length of the crank-shaped portion including these corner portions is significantly shortened. Of the two corners T2 and T3 forming one U-turn part of the meander pattern as shown in the figure, if the corner T2 closer to the center of the antenna element 14 is thickened, the frequency fluctuation becomes particularly large. Tended to be. It is considered that this is due to the volume of the dielectric material around the conductor. Since the conductor buried in the vicinity of the periphery of the dielectric chip (resin molding) is in the periphery of the chip, the dielectric constant contributes to the state including the outside (air). Therefore, the effective dielectric constant is lowered, and the wavelength shortening effect of the dielectric is not great. Therefore, a change in conductor length does not cause a large change in frequency.
However, the conductor near the center of the dielectric chip has a smaller air contribution rate than the conductors at the periphery, and as a result, the effective permittivity is high and the wavelength shortening effect is large. Therefore, it is considered that a slight change in conductor length causes a large change in frequency.

Therefore, in this embodiment, the corner portion T2 closer to the center of the antenna element 14 is chamfered without providing a fillet portion, and the corner portion T2 closer to the outer surface of the resin molded body 16 (farther from the center). The corner portion T3 is provided with the fillet portion 30 and the chamfering is omitted, thereby improving the mechanical strength of one U-turn portion as a whole and reducing the frequency fluctuation.

More specifically, in this embodiment, the first meander pattern 14a and the second meander pattern 14b are arranged so that the meander pitch directions are orthogonal to each other. The first meander pattern 14a has a wider meander width than the second meander pattern 14b. During resin molding, one end of the first meander pattern 14a in the meander width direction is arranged near the surface 30a of the cavity 30 on which the gate 37 is provided, and the other end is arranged at a position away from the surface 30a. It It is expected that the resin flowing into the cavity during resin molding will flow substantially along the meander width direction of the first meander pattern 14a. Corner T2
Is closer to the gate 37 than the corner portion T1 adjacent thereto during resin molding. The corner T2 is
It is located closer to the gate 37 than the corner T3 adjacent thereto. In other words, the first meander pattern 14a
Inside, the corner T2 is closest to the gate 37,
Adjacent corner portions T1 and T3 are located at positions sandwiching this. A fillet portion 12 is provided on each of the corner portions T1 and T3. Further, chamfering on the outside of these corner portions T1, T2, T3 is omitted.

In some cases, one of the fillet portions 12 of the corner portions T1 and T3 may be omitted. Further, it may not be necessary to omit the chamfering of the corner portions T1, T2, T3. In addition, a gate 3 for injecting resin at the time of resin molding
7 usually remains as a gate mark on the resin molded product 30.

With the above-mentioned structure, since the portion where the connecting portion of the first meander pattern 14a cannot be formed, especially the periphery of the corner portion T2 is reinforced, it is possible to suppress the deformation of the antenna element 14 during resin molding. A small antenna with stable characteristics can be obtained. Further, in this embodiment, chamfering is omitted at the three corners T1, T2, T3, but all the other corners are chamfered, and most of the chamfered corners are
By omitting the chamfering of the three corners T1, T2, T3, there is little risk that the widening of the band will be hindered.

In the above embodiment, the case where the antenna element 14 is embedded in the resin molding 16 has been described. However, the small antenna of the present invention has a configuration in which the antenna element 14 is integrally provided on the surface of the resin molding 16. You can also do it. In this case, as a mold for molding the resin molded body, a mold in which a cavity is formed in only one of the upper mold and the lower mold is used, and the mold of the mold in which the cavity is not formed is used. The antenna element may be set on the surface and injection molding may be performed.

[0067]

As described above, according to the present invention,
In a small antenna in which an antenna element having a meander pattern and a resin molded body are integrated, deformation of the meander pattern can be suppressed during molding of the resin molded body, so that a small antenna with stable antenna characteristics can be obtained.

[Brief description of drawings]

1A, 1B, and 1C are explanatory views of a fillet portion and a chamfered portion used in the present invention, respectively.

FIG. 2 is a plan view showing an embodiment of a small antenna according to the present invention.

3 is a plan view showing a conductor pattern used to manufacture the small antenna of FIG.

FIG. 4 is a plan view showing a conductor pattern having chamfers at all corners for comparison with the conductor pattern of FIG.

FIG. 5 is a plan view showing a conductor pattern used in another embodiment of the small antenna according to the present invention.

[Explanation of symbols] 10: Strip conductor 12: fillet T: Corner 14: Antenna pattern 14a: first meander pattern 14b: second meander pattern 16: Resin molding 18: Power supply terminal 20: Fixed terminal 22: Conductor pattern 24: Frame 26: Connection part 30: Mold cavity 32: Chamfer 33: First straight part of the meander pattern 34: Second straight part of the meander pattern 37: Gate

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takahiro Ueno             2-6-1, Marunouchi, Chiyoda-ku, Tokyo             Kawa Electric Industry Co., Ltd. F-term (reference) 5J046 AA05 AA10 AB06 QA02

Claims (22)

[Claims] 1. A small antenna provided with an antenna element (14) having a band-shaped conductor meander pattern, and a resin molding (16) molded so as to be integrated with the antenna element, wherein a corner of the meander pattern is provided. A small antenna characterized in that a fillet portion (12) is provided inside the corner portion of the portion that is easily deformed during resin molding. 2. The small antenna according to claim 1, wherein
The fillet portion (12) is a corner portion (T where the connecting portion (26) with the outer frame (24) of the meander pattern is not nearby.
Small antenna provided in 1). 3. The small antenna according to claim 1, wherein:
The antenna element (14) has a plurality of meander patterns (14a, 14b) with different meander traveling directions,
A small antenna characterized in that the fillet portion (12) is provided in the corner portion (T1) where the meandering traveling direction changes. 4. The small antenna according to claim 1, wherein
A small antenna characterized in that most of the corner portions of the meander pattern are chamfered on the outside, and the corner portion (T1) provided with the fillet portion (12) is not chamfered on the outside. 5. The small antenna according to claim 4, wherein:
Two corners that make up one U-turn (T2,
If one of the corners (T2) of T3) is likely to be deformed during resin molding, the corner (T2) closer to the center of the antenna element (14) does not have a fillet portion and chamfering is omitted. A small antenna characterized in that a corner portion (T3) farther from the center is provided with a fillet portion (12) to omit chamfering. 6. The small antenna according to claim 1, wherein
The antenna element has a first meander pattern (14a) and a second meander pattern (14a) which have different meandering directions.
and b) are arranged so that the pitch directions of the meanders are orthogonal to each other, and the first meander pattern has a corner part at a position close to the gate into which the resin is injected at the time of resin molding and a corner part at a position apart from the corner part. And a fillet (12) is provided at a corner located adjacent to a corner located near the corner. 7. A small antenna comprising an antenna element (14) having a meander pattern of a strip conductor and a resin molding (16) molded so as to be integrated with the antenna element, wherein the antenna element (1)
A small antenna characterized in that a fillet portion (12) is provided inside at least one of the plurality of corner portions of 4). 8. The small antenna according to claim 7,
The small antenna, wherein the antenna element (14) has a corner portion (T4) having a chamfered outside and a corner portion (T1) provided with a fillet portion (12) without the chamfering of the outside. 9. The miniature antenna according to claim 7, wherein a plurality of corner portions of the antenna element (14) are chamfered on the outer side, or
A small antenna, characterized in that it is one of the corner portions (T1) provided with a fillet portion (12) by omitting chamfering on the outside. 10. The small antenna according to claim 7, wherein the corner portion provided with the fillet portion (12) is a corner portion that is more easily deformed than other corner portions. A small antenna that does. 11. The small antenna according to claim 7, wherein the corner portion provided with the fillet portion (12) is
A small antenna characterized in that a connecting portion (26) with the outer frame (24) of the antenna element (14) is a corner portion (T1) not near. 12. The antenna according to claim 7, wherein a corner portion provided with the fillet portion (12) is close to a gate (37) into which resin is injected during resin molding. T5) is a small antenna. 13. The small antenna according to claim 7, wherein the antenna element (14) has a plurality of meander patterns (14a, 14b) having different meander traveling directions, and the fillet portion (12). ) Is provided at the corner
A small antenna characterized by a corner (T1) where the meandering direction changes. 14. The miniature antenna according to claim 7, further comprising two corner portions (T2, T3) forming one U-turn portion, the two corner portions (T2, T3). A small antenna characterized in that a fillet portion (12) is provided on only one of T3). 15. The small antenna according to claim 14, wherein the corner portion of the two corner portions (T2, T3) where the fillet portion (12) is provided is farther from the center of the antenna element (14). A small antenna characterized in that it is a corner portion (T3). 16. The small antenna according to claim 7, wherein a corner portion (T) that is more easily deformed than other corners among the plurality of corner portions of the meander pattern.
When 2) is located near the center of the resin molded body (16), it is located away from the center of the resin molded body (16),
The corner part (T1, T1) connected to the corner part (T2)
Small antenna having a fillet (12) on at least one of T3). 17. The miniature antenna according to claim 7, wherein the antenna element (14) has a crank-shaped pattern including three corners (T1, T2, T3). When one corner portion (T2) of the pattern is located near the center of the resin molded body (16), it is located away from the center of the resin molded body (16) and is connected to the corner portion (T2). A small antenna characterized in that a fillet portion (12) is provided on at least one of the corner portions (T1, T3). 18. The small antenna according to claim 7, wherein the gate (3) into which the resin is injected at the time of resin molding.
When the corner portion (T2) close to 7) is located near the center of the resin molding (16), the resin molding (16)
A small antenna characterized in that a fillet portion (12) is provided on at least one of the corner portions (T1, T3) connected to the corner portion (T2) and located away from the center of the small antenna. 19. The small antenna according to claim 7, wherein the antenna element (14) includes a first meander pattern (14a) and a second meander pattern (14a) arranged so that pitch directions of meanders having different meander directions are orthogonal to each other. The first meander pattern (14a) has a corner portion (T2) located near the center of the resin molded body (16) and the center of the resin molded body (16). It has a corner part (T1, T3) which is in a distant position and is connected to the corner part (T2), and a fillet part (12) is provided on at least one of the connected corner parts (T1, T3). Small antenna that is characterized by being. 20. The small antenna according to claim 7, wherein the antenna element (14) includes a first meander pattern (14a) and a second meander pattern (14a) arranged so that pitch directions of meanders having different meander directions are orthogonal to each other. The first meander pattern (14a) is located near the gate (37) into which the resin is injected during resin molding and near the center of the resin molded body (16). The corner portion (T1, T3) which is located at a position apart from the corner portion (T2) and the gate (37) and which is connected to the corner portion (T2). ) At least one of the fillets (1
2) A small antenna characterized by being provided. 21. The small antenna according to claim 14, wherein chamfering is omitted in the corner portion (T2) located near the center of the resin molded body (16). 22. The miniature antenna according to claim 7, wherein the antenna element (14) further comprises a corner portion (T6) provided with a fillet portion (12) and chamfered. A characteristic small antenna.