JP2003051705A - Surface mount antenna and communication equipment employing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized surface mount antenna with high performance that can transceive a signal in a plurality of frequency bands. SOLUTION: Radiation electrodes 3, 4 are provided on a dielectric base 2. The radiation electrode 3 is formed substantially into a loop where an open end 3k is opposed to a feeding section 3a at an interval. An electric field is concentrated between the open end 3k of the radiation electrode 3 and the feeding section 3s. The open end 3k of the radiation electrode 3 is spaced from an open end 4k of the radiation electrode 4 with an interval to prevent mutual interference. A loading electrode 8 is provided in the vicinity of the open end 4k of the radiation electrode 4 to concentrate the electric field between the electrode 8 and the open end 4k. Since the electromagnetic coupling between the radiation electrodes 3, 4 can be relaxed, the electromagnetic coupling amount between the radiation electrodes 3, 4 can easily be adjusted even when the interval between the radiation electrodes 3, 4 is decreased so as to downsize the surface mount antenna 1. Further, the radiation electrodes 3, 4 can easily be impedance-matched and the gain can be enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount antenna mounted on a circuit board of a communication device and a communication device using the same.

[0002]

BACKGROUND ART FIG. 8 is a schematic perspective view showing an example of a surface mount antenna. The surface mount antenna 25 has a plurality of signals (radio waves) in different frequency bands.
Which has a rectangular parallelepiped dielectric base 26, and the surface of the dielectric base 26 is
The feeding radiation electrode 27 and the parasitic radiation electrode 28 are arranged adjacent to each other with a gap.

In this surface mount antenna 25,
For example, by being mounted on the circuit board of the communication device, the power supply radiation electrode 27 is connected to the signal supply source 32 of the communication device via the power supply electrode 30 on the side surface 26c of the dielectric substrate 26. In addition, the parasitic radiation electrode 28 is grounded to the ground of the communication device via the grounding electrode 31 on the side surface 26c of the dielectric substrate 26.

When a signal is supplied from the signal supply source 32 to the power supply electrode 30, the signal is transmitted to the power supply radiation electrode 27 and also supplied to the parasitic power supply electrode 28 by electromagnetic coupling. The supply of the signal causes the feeding radiation electrode 27 and the non-feeding radiation electrode 28 to resonate, so that signal transmission or reception (antenna operation) is performed.

The feeding radiation electrode 27 is constructed so as to be capable of transmitting or receiving a signal in a predetermined basic frequency band and a higher frequency band higher than this. However, since the frequency band on the high-order side is narrow in the feeding radiation electrode 27 alone, in this example, in order to broaden the frequency band on the high-order side, the feeding radiation electrode is set in the high-order frequency band. 27 and the parasitic radiation electrode 28 are configured so as to create a multiple resonance state.

[0006]

However, in order for both the feeding radiation electrode 27 and the parasitic radiation electrode 28 adjacent to each other to perform good antenna operation, the electromagnetic coupling between the feeding radiation electrode 27 and the parasitic radiation electrode 28 is required. The amount should be appropriate.

For example, if the electromagnetic coupling between the feeding radiation electrode 27 and the parasitic radiation electrode 28 is too strong, the feeding radiation electrode 2
7 and the parasitic radiation electrode 28 strongly interfere with each other, which causes a problem that the feeding radiation electrode 27 and the parasitic radiation electrode 28 cannot create a favorable multiple resonance state.

In order to solve such a problem, if the amount of electromagnetic coupling between the feeding radiation electrode 27 and the parasitic radiation electrode 28 is made appropriate, the gap between the feeding radiation electrode 27 and the parasitic radiation electrode 28 is adjusted. is necessary. However, when the size of the dielectric substrate 26 is restricted according to the demand for miniaturization of the antenna, the feeding radiation electrode 27 and the parasitic radiation electrode 28 are appropriately coupled so that the electromagnetic coupling amount becomes appropriate. There is a problem that it is very difficult to adjust the distance between the 27 and the parasitic radiation electrode 28. In other words, if the distance between the feeding radiation electrode 27 and the parasitic radiation electrode 28 is adjusted so that the electromagnetic coupling amount between the feeding radiation electrode 27 and the parasitic radiation electrode 28 becomes appropriate, the dielectric substrate 26
However, there is a problem that it is difficult to downsize the surface mount antenna 25.

The present invention has been made to solve the above problems, and an object thereof is to reduce the size of a base (miniaturization of an antenna) when forming a plurality of radiation electrodes on the base. An object of the present invention is to provide a surface-mounted antenna that easily adjusts the electromagnetic coupling amount of the plurality of radiation electrodes to an appropriate coupling amount, and a communication device including the same.

[0010]

In order to achieve the above object, the present invention has the following constitution as means for solving the above problems. That is, a first aspect of the present invention is a surface-mounted antenna in which a plurality of strip-shaped radiation electrodes that perform an antenna operation are formed on a surface of a base body with a gap between each other, and one end side of each radiation electrode is externally connected. Of the radiation electrode, the other end side of which is an open end, and the open ends of the respective radiation electrodes are spaced apart from each other with a distance preventing mutual interference, and An electric field concentration electrode for concentrating an electric field is arranged between the open end of the radiation electrode and the open end via a space, and the electric field concentration electrode is a power supply unit of the radiation electrode, or It is characterized in that it is a separately provided electrode for loading.

A second invention comprises the configuration of the first invention,
The base body has a rectangular parallelepiped shape, and the open ends of the radiation electrodes are formed on different surfaces of the base body, respectively.

A third aspect of the invention has the structure of the first or second aspect of the invention, wherein at least one of the radiation electrodes has a substantially loop shape whose open end is disposed close to the power feeding portion with a gap. It is characterized by that.

A fourth invention comprises the structure of the first, second or third invention, and a plurality of radiation electrodes are arranged at least partially in parallel, and the radiation electrodes are adjacent to each other in the parallel arrangement portion. The radiation electrodes are characterized in that the directions from the feeding portion to the open end are opposite to each other.

According to a fifth aspect of the present invention, which comprises any one of the first to fourth aspects of the present invention, the base has a rectangular parallelepiped shape, and each radiation electrode is formed along the longitudinal direction of the base. The radiation electrodes are formed on different surfaces of the substrate.

A sixth invention relates to a communication device, and the first to fifth inventions are provided.
The invention is characterized in that the surface mount antenna according to any one of the inventions is provided.

In the present invention, the open ends of the radiation electrodes are spaced apart from each other with a distance preventing mutual interference, and an electric field for concentrating an electric field between the open ends of the radiation electrodes. Electrodes for concentration are arranged. For this reason,
Since the electromagnetic coupling between the radiation electrodes is relaxed, the radiation electrodes can be arranged close to each other while suppressing the mutual interference of the radiation electrodes, and the size of the substrate (surface mount antenna) can be reduced. be able to. In addition, it becomes easy to adjust the electromagnetic coupling amount between the radiation electrodes to an appropriate coupling amount so that each radiation electrode can perform favorable antenna operation.

Therefore, it is possible to provide a small surface mount antenna which can transmit or receive signals in a plurality of different frequency bands. Further, as the surface mount antenna is downsized, the communication device can be downsized.

Further, by adjusting the electromagnetic coupling amount between the radiation electrodes to an appropriate coupling amount, it becomes easy to obtain matching of the radiation electrodes. Furthermore, since each radiation electrode can perform good resonance operation, the gain of each radiation electrode can be improved and the sensitivity of the surface mount antenna can be improved. Thereby, the reliability of signal transmission / reception of the surface mount antenna and the communication device can be improved.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows an example of a surface-mounted antenna, which is characteristic of the communication device of the first embodiment, together with a matching circuit and a signal supply source. Note that there are various configurations of the communication device, and in this first embodiment example,
Any configuration may be adopted for the communication device other than the surface mount antenna, and here, the configuration other than the surface mount antenna of the communication device is omitted.

The surface-mounted antenna 1 of the first embodiment has a rectangular parallelepiped base 2 made of a dielectric material such as ceramics, on which two strip-shaped radiation electrodes 3 and 4 are formed. Has been done. The radiation electrode 3 extends from the side surface 2b of the base body 2 through the bottom surface 2f, the side surface 2d, and the upper surface 2a to the side surface 2
The radiation electrode 3 is formed in a substantially loop shape returning to b.
Both ends of the are opposed to each other with a space therebetween. The radiation electrode 4 is formed from the bottom surface 2f of the base 2 to the side surface 2d via the side surface 2b and the upper surface 2a.

In the first embodiment, both of the radiation electrodes 3 and 4 have end portions 3s and 4s formed on the side surface 2b, respectively, and a matching circuit formed on a circuit board of a communication device, for example. It is connected to the signal supply source 6 via 5. That is, in the radiation electrodes 3 and 4, the end portions 3s and 4s on the side surface 2b connected to the signal supply source 6 serve as power feeding portions, respectively.

The radiation electrodes 3 and 4 have open ends 3k and 4k at the other ends of the feeding portions 3s and 4s, respectively. In this first embodiment example, the open end 3k of the radiation electrode 3 is
And the open end 4k of the radiation electrode 4 are disposed on the side surfaces 2b and 2d of the base 2 which face each other.
In other words, the open end 3k, which is the strongest electric field portion of the radiation electrode 3, and the open end 4k, which is the strongest electric field portion of the radiation electrode 4, cause mutual interference between the radiation electrode 3 and the radiation electrode 4. They are spaced apart with a spacing to prevent them.

In addition, in the first embodiment, the radiation electrode 3 has a substantially loop shape, and the open end 3k of the radiation electrode 3 is arranged with a space between it and the feeding portion 3s. And a configuration in which an electric field is concentrated between the power feeding portion 3s. A loading electrode 8 is formed in the vicinity of the open end 4k of the radiation electrode 4 with a space therebetween, and the electric field is concentrated between the open end 4k of the radiation electrode 4 and the loading electrode 8. ing.

The loading electrode 8 may be, for example, conductively connected to the ground portion of the circuit board of the communication device to have a ground potential, or may not be grounded to the ground and have no ground potential. Whether or not the loading electrode 8 is grounded is appropriately selected. When the loading electrode 8 is not grounded, for example, the loading electrode 8 is used to improve the wettability of the solder when the base 2 is mounted on the circuit board of the communication device using solder. It may be used as a base electrode (fixing electrode).

In the first embodiment, the radiation electrodes 3, 4
Are arranged in parallel on the upper surface 2a of the base body 2, and in this arranged portion, the direction from the feeding portion 3s of the radiation electrode 3 to the open end 3k and the direction from the feeding portion 4s of the radiation electrode 4 to the open end 4k. The directions are opposite to each other.

When a signal is supplied to each of the radiation electrodes 3 and 4 from the signal supply source 6 through the matching circuit 5,
The signal energizes the regions from the power feeding portions 3s and 4s to the open ends 3k and 4k. By this signal conduction, the radiation electrode 3,
The signal 4 is transmitted or received (antenna operation) by the resonance operation of the device 4. In the first embodiment, the electrical lengths of the radiation electrodes 3 and 4 and the electrical lengths of the radiation electrodes 3 and 4 are set so that the radiation electrodes 3 and 4 can transmit and receive signals in different preset frequency bands. The distance between the open end 3k of the radiation electrode 3 and the feeding portion 3s and the distance between the open end 4k of the radiation electrode 4 and the loading electrode 8 are designed. By designing the radiation electrodes 3 and 4 in this way, the surface-mounted antenna 1 can have a frequency of 1
It is possible to transmit or receive signals in a plurality of different frequency bands such as 500 MHz band.

According to the first embodiment, the open ends (portions where the electric field is strong) 3k and 4k of the radiation electrodes 3 and 4 are formed on the side surfaces 2b and 2d of the base 2 which face each other and are separated from each other. It is arranged. In addition, the power supply portion 3s is arranged at the open end 3k of the radiation electrode 3 with a space,
An electric field is concentrated between the open end 3k and the power feeding portion 3s, and
The loading electrode 8 is provided at the open end 4k of the radiation electrode 4 with a space therebetween.
Are arranged, and an electric field is concentrated between the open end 4k and the loading electrode 8.

With such a structure, the electromagnetic coupling between the radiation electrodes 3 and 4 can be significantly relaxed. Thereby, even if the distance between the radiation electrodes 3 and 4 is narrowed, mutual interference between the radiation electrodes 3 and 4 can be suppressed, and both the radiation electrodes 3 and 4 can perform good antenna operation. Therefore, it becomes easy to adjust the electromagnetic coupling amount between the radiation electrodes 3 and 4 to an appropriate coupling amount.

As described above, even if the distance between the radiation electrodes 3 and 4 is narrowed, the electromagnetic coupling amount between the radiation electrodes 3 and 4 can be made appropriate and mutual interference can be prevented. The type antenna 1) can be miniaturized.

The radiation electrodes 3 and 4 are formed on two or more surfaces of the substrate 2. In particular, since the radiation electrode 3 has a loop shape that substantially surrounds the substrate 2, the electrical length of the radiation electrodes 3 and 4 can be increased without increasing the size of the substrate 2. This configuration is also a configuration that can contribute to miniaturization of the base 2 (surface-mounted antenna 1).

Further, in the first embodiment, the radiation electrodes 3 and 4 are arranged side by side on the upper surface 2a of the base body 2 with a space between them. Are opposite to each other. This configuration is involved in mitigating mutual interference between the radiation electrodes 3 and 4.

Furthermore, in the first embodiment, as described above, mutual interference between the radiation electrodes 3 and 4 can be suppressed,
The radiation electrode 3 and the radiation electrode 4 can be easily aligned. Further, both the gains of the radiation electrode 3 and the radiation electrode 4 can be improved, and the sensitivity of the surface mount antenna 1 can be improved. Thereby, the reliability of wireless communication between the surface mount antenna 1 and the communication device can be improved.

The circuit configuration of the matching circuit 5 shown in FIG. 1 is an example, and the matching circuit 5 is not limited to the circuit configuration of FIG. 1 and may have other circuit configurations.

The second embodiment will be described below. In the description of the second embodiment, the same components as those in the first embodiment will be designated by the same reference numerals, and duplicate description of the common parts will be omitted.

The surface mount antenna 1 of the second embodiment is also characterized, and the surface mount antenna 1 of the second embodiment has the surface of the first embodiment as shown in FIG. The mounting type antenna 1 has almost the same structure as that of the mounting type antenna 1, but the formation position of the open end 4k of the radiation electrode 4 is different from that of the first embodiment. That is, in the second embodiment, the open end 4k of the radiation electrode 4 is arranged at the end of the upper surface 2a of the base 2 on the side surface 2d side. Also in this case, the open end 3k of the radiation electrode 3 and the open end 4k of the radiation electrode 4
Are in a state of being spaced apart from each other with a distance preventing mutual interference.

Also in the second embodiment, as in the first embodiment, a loading electrode 8 is provided on the side surface 2d of the substrate 2, and the loading electrode 8 and the radiation electrode 4 are provided.
The electric field is concentrated between the open end 4k and the open end 4k.

According to the second embodiment, the structure similar to that of the first embodiment is provided, so that the same effect as that of the first embodiment, that is, the mutual interference of the radiation electrodes 3 and 4 can be obtained. The effect that the surface mount antenna 1 (base 2) can be downsized while preventing it, the effect that the radiation electrodes 3 and 4 can be easily matched, and the gain of the radiation electrode 3 and the radiation electrode 4 can be obtained. It is possible to obtain an effect that both can be easily improved and the reliability of the surface-mounted antenna 1 and the communication device can be improved.

The third embodiment will be described below. In the description of the third embodiment, the same reference numerals are given to the same components as those of the above-described respective embodiments, and the duplicate description of the common portions will be omitted.

In the third embodiment, as shown in FIG. 3, the loading electrode 8 shown in each of the embodiments is not provided, and the open end 4k side of the radiating electrode 4 is extended to cause the radiation. The open end 4k of the electrode 4 is formed on the bottom surface 2f of the base 2. An electric field is concentrated between the open end 4k and the feeding portion 4s of the radiation electrode 4 or the ground portion of the circuit board of the communication device.

Further, in the third embodiment, the open end 3k of the radiation electrode 3 is formed at the end of the upper surface 2a of the base 2 on the side surface 2b side. Also in this case, as in each of the above-described embodiments, the electric field is concentrated between the open end 3k of the radiation electrode 3 and the feeding portion 3s of the radiation electrode 3. Further, the open end 3k of the radiation electrode 3 and the open end 4k of the radiation electrode 4 are in a state of being separated from each other with a gap preventing mutual interference.

Also in the third embodiment, the open end 3k of the radiating electrode 3 and the open end 4k of the radiating electrode 4 are spaced apart from each other and the radiating electrode is also provided in the same manner as in the above-mentioned respective embodiments. 3 is configured to concentrate the electric field on the open end 3k side of 3 and the electric field on the open end 4k side of the radiation electrode 4. From this, the electromagnetic coupling of the radiation electrodes 3 and 4 can be relaxed, and mutual interference between the radiation electrodes 3 and 4 can be suppressed.

Therefore, the amount of electromagnetic coupling between the radiation electrodes 3 and 4 is adjusted so that both the radiation electrodes 3 and 4 can perform good antenna operation without increasing the distance between the radiation electrodes 3 and 4. It becomes easy to adjust. As a result, it becomes possible to transmit or receive signals in a plurality of different frequency bands, and it is possible to provide a small surface mount antenna 1 and a communication device.

Further, the radiation electrodes 3 and 4 can be easily aligned. Furthermore, both the gains of the radiation electrodes 3 and 4 can be improved. As a result, the sensitivity of the surface mount antenna 1 can be improved, and the surface mount antenna 1 can be improved.
And the reliability of communication of a communication device can be improved.

Although the open end 3k of the radiation electrode 3 is formed on the upper surface 2a of the substrate 2 in the third embodiment, the radiation electrode is similar to the first and second embodiments. The open end 3k of 3 may be formed on the side surface 2b of the base 2.

The fourth embodiment will be described below. In the description of the fourth embodiment, the same components as those in the above-described embodiments will be denoted by the same reference numerals, and duplicate description of the common parts will be omitted.

In the fourth embodiment, as shown in FIGS. 4 and 5, the radiation electrodes 3 and 4 formed along the longitudinal direction A of the base 2 are formed on different surfaces. It is characterized by that.

That is, in the example shown in FIG. 4, the radiation electrode 3
Has the same shape as that of each of the above-described embodiments, and the portion of the radiation electrode 3 formed along the longitudinal direction A of the base 2 is formed on the portion formed on the bottom surface 2f of the base 2 and the upper surface 2a. It is the part that is being done.

The radiation electrode 4 is formed from the bottom surface 2f of the base 2 to the side surface 2b, and the side surface 2b is the upper surface 2a.
The side surface 2e is bent toward the side and bent toward the side surface 2e, and the side surface 2e is further formed along the longitudinal direction A of the base 2 to the side surface 2d. Then, it is further extended, and the open end 4k of the radiation electrode 4 is disposed in the vicinity of the loading electrode 8 on the side surface 2d. This radiation electrode 4
In the above, the portion of the radiation electrode 4 formed along the longitudinal direction A of the base 2 is a portion formed on the side surface 2 e of the base 2.

In the example shown in FIG. 5, in the radiation electrode 3,
The side surface 2b is formed from the side surface 2b toward the bottom surface 2f, and the bottom surface 2f is formed along the longitudinal direction A of the base 2.
to d. Then, the side surface 2d is bent toward the upper surface 2a while being formed toward the side surface 2c. Further, the side surface 2c is formed along the longitudinal direction A of the base body 2 and the feeding portion 3s of the radiation electrode 3 is formed. The open end 3k is arranged in the vicinity of. The part of the radiation electrode 3 formed along the longitudinal direction A of the base 2 is the part formed on the bottom surface 2f and the part formed on the side surface 2c.

The radiation electrode 4 has a shape similar to that shown in FIG. 4, and the portion of the radiation electrode 4 formed along the longitudinal direction A of the base 2 is formed on the side surface 2e of the base 2. It is the part that is.

Also in the fourth embodiment, the open end 3k of the radiating electrode 3 and the open end 4k of the radiating electrode 4 are separated from each other with a distance preventing mutual interference, as in each of the above-described embodiments. It is arranged. And the open end 3k of the radiation electrode 3
Is arranged in the vicinity of the power feeding section 3s and is configured to concentrate an electric field between the open end 3k and the power feeding section 3s. Also,
A loading electrode 8 is formed in the vicinity of the open end 4k of the radiation electrode 4, and the electric field is concentrated between the open end 4k and the loading electrode 8.

With this structure, the same excellent effects as those of the above-described embodiments can be obtained. In addition, in the fourth embodiment, the portions of the radiation electrodes 3 and 4 formed along the longitudinal direction A of the base body 2 are formed on different surfaces of the base body 2, so that the radiation electrode is formed. There is no part where 3 and 4 are arranged side by side.
Mutual interference of can be suppressed more reliably.

The present invention is not limited to the above embodiments, but various embodiments can be adopted. For example, in each of the above-described embodiments, the power feeding unit 3s of the radiation electrode 3 is
And the feeding portion 4s of the radiation electrode 4 was formed on the same surface (side surface 2b) of the base body 2, but as shown in FIGS. 6A and 6B, the feeding portion 3s of the radiation electrode 3 and The radiation electrode 4 and the feeding portion 4s may be formed on different surfaces of the substrate 2.

Further, in each of the above embodiments, the radiation electrode 3
Has a substantially loop shape and is configured to concentrate an electric field between the open end 3k and the feeding portion 3s. For example, as shown in FIG. 6B, the radiation electrode 3 is similar to the radiation electrode 4. The shape may be adopted, and the loading electrode 8 may be provided in the vicinity of the open end 3k of the radiation electrode 3 to concentrate the electric field between the open end 3k and the loading electrode 8. Of course, also in this case, the open end 3k of the radiating electrode 3 and the open end 4k of the radiating electrode 4 are spaced apart from each other with a distance preventing mutual interference.

Further, in each of the above embodiments, the open ends 3k and 4k of the radiation electrodes 3 and 4 are formed on different surfaces of the base body 2. For example, the open ends 3k and 4k are
If the radiation electrodes 3 and 4 are separated from each other to such an extent that mutual interference can be suppressed, the open ends 3k and 4k are formed on the same surface of the base body 2 as shown in FIG. 7, for example. Good.

As described above, according to the present invention, the open ends 3k and 4k of the radiation electrodes 3 and 4 are arranged with a space for preventing mutual interference, and in the vicinity of the open ends 3k and 4k. As long as the electric field concentration electrodes for concentrating the electric field are arranged between the open ends 3k and 4k, the shapes of the radiation electrodes 3 and 4 and the presence or absence of the loading electrode 8 are particularly limited. However, it may be set appropriately. In addition,
When the radiation electrodes 3 and 4 have portions arranged in parallel, the signal conduction direction of the radiation electrode 3 and the signal conduction direction of the radiation electrode 4 are opposite to each other in the arrangement portions. It is desirable that the radiation electrodes 3 and 4 are formed on the radiating electrodes.

Further, in each of the above-described embodiments, two radiation electrodes are formed, but of course, three or more radiation electrodes may be formed, and the number of radiation electrodes formed is limited to the embodiment. Not a thing.

[0059]

According to the present invention, a plurality of radiation electrodes are formed on the substrate, and the open ends of these radiation electrodes are spaced apart from each other with a spacing preventing mutual interference, and An electric field concentration electrode for concentrating an electric field is arranged between the open end of the radiating electrode and the open end of the radiating electrode via a space. Thereby, the electromagnetic coupling between the radiation electrodes can be relaxed.

Therefore, the amount of electromagnetic coupling between the radiation electrodes can be easily adjusted. As a result, each radiation electrode can be operated as an antenna, and signals in a plurality of different frequency bands can be transmitted or received satisfactorily. Further, even if the distance between the radiation electrodes is narrowed, it is easy to adjust the electromagnetic coupling amount between the radiation electrodes to a good coupling amount, so that the surface mount antenna can be downsized. In addition, it is possible to promote the downsizing of the communication device.

Therefore, it is possible to satisfactorily perform transmission or reception of signals in a plurality of different frequency bands, and it is possible to easily obtain a small surface mount antenna and a communication device.

Further, according to the present invention, as described above, the electromagnetic coupling amount between the respective radiation electrodes can be adjusted to a favorable coupling amount, so that the radiation electrodes can be easily aligned. Furthermore, it becomes easy to improve the gain of each radiation electrode. Thereby, the sensitivity of the surface-mounted antenna can be increased, and the reliability of communication of the surface-mounted antenna and a communication device including the same can be improved.

Further, in the case where at least one radiation electrode has a substantially loop shape, the above-described excellent effects can be obtained, and the radiation electrode can be formed without enlarging the substrate. Since it is possible to increase the electric length of the antenna, it is possible to promote miniaturization of the surface mount antenna.

Further, at least a part of the plurality of radiation electrodes is arranged in parallel, and the radiation electrodes adjacent to each other in the juxtaposed portion are opposite to each other in the direction from the feeding portion to the open end. In this case, since the current-carrying directions of the signals of the adjacent radiation electrodes are opposite to each other in the juxtaposed portion, mutual interference between the radiation electrodes can be further alleviated.

Furthermore, each of the radiation electrodes has a portion formed along the longitudinal direction of the base body, and the portions of the radiation electrodes are formed on different surfaces of the base body. In addition, since the distance between the radiation electrodes can be increased, mutual interference between the radiation electrodes can be suppressed more reliably.

[Brief description of drawings]

FIG. 1 is a model diagram schematically showing an example of a characteristic surface mount antenna in a first embodiment together with a matching circuit and a signal supply source.

FIG. 2 is a diagram illustrating a surface mount antenna according to a second embodiment.

FIG. 3 is a diagram for explaining a surface mount antenna of a third embodiment example.

FIG. 4 is a diagram for explaining a surface mount antenna according to a fourth embodiment.

FIG. 5 is a view for explaining another example of the surface mount antenna of the fourth embodiment.

FIG. 6 is a model diagram for explaining another embodiment example.

FIG. 7 is a model diagram for explaining another embodiment example.

FIG. 8 is a diagram for explaining a conventional example of a surface mount antenna.

[Explanation of symbols] 1 Surface mount antenna 2 base 3,4 Radiation electrode 8 Loading electrodes

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5J046 AA04 AA07 AA12 AB06 AB11                       PA07                 5J047 AA04 AA07 AA12 AB06 AB11                       FD01

Claims (6)

[Claims] 1. A surface mount antenna in which a plurality of strip-shaped radiation electrodes for performing an antenna operation are formed on a surface of a base body with a space between each other, and one end of each of the radiation electrodes receives a signal from the outside. The radiating electrode is provided with a power feeding portion, the other end side is an open end, and the open ends of the respective radiation electrodes are spaced apart from each other with a distance preventing mutual interference. An electric field concentrating electrode for concentrating an electric field is arranged between the open end and the open end via a space, and the electric field concentrating electrode is provided at a power feeding portion of the radiation electrode or separately provided. Surface mounted antenna characterized by being used as an electrode for loading. 2. The surface mount antenna according to claim 1, wherein the base has a rectangular parallelepiped shape, and the open ends of the respective radiation electrodes are formed on different surfaces of the base. 3. The surface mounting according to claim 1 or 2, wherein at least one radiation electrode has an open end formed in a substantially loop shape arranged in proximity to the power feeding portion with a gap. Type antenna. 4. A plurality of radiation electrodes are arranged at least partially in parallel, and the radiation electrodes are arranged in parallel.
The surface-mounted antenna according to claim 1, 2 or 3, wherein adjacent radiation electrodes are arranged such that the directions from the feeding portion toward the open end are opposite to each other. 5. The substrate has a rectangular parallelepiped shape, and each radiation electrode is
5. Each of the radiation electrodes has a portion formed along the longitudinal direction of the base body, and the portions of the respective radiation electrodes are formed on different surfaces of the base body. The surface mount antenna according to item 1. 6. A communication device comprising the surface mount antenna according to claim 1. Description: