WO2007020728A1

WO2007020728A1 - Antenna structure and wireless communication apparatus provided with same

Info

Publication number: WO2007020728A1
Application number: PCT/JP2006/304620
Authority: WO
Inventors: Nobuhito Tsubaki; Kazunari Kawahata
Original assignee: Murata Manufacturing Co., Ltd.
Priority date: 2005-08-12
Filing date: 2006-03-09
Publication date: 2007-02-22
Also published as: JPWO2007020728A1; JP4508242B2

Abstract

An antenna structure is provided with a radiation electrode (4) for a high frequency band, for performing antenna operation at a resonance frequency of the high frequency band, and a base body (3) whereupon the radiation electrode (4) is arranged. The base body (3), for instance, is mounted on a printed board (2), and in a region whereupon the base body (3) is mounted, for instance, a coil-like radiation electrode (5) for a low frequency band is arranged. The radiation electrode (4) is formed on the base body (3), except on a base body portion whereupon a magnetic field having a high magnetic flux density passes at a coil center part of the radiation electrode (5). The base body (3) is composed of a mixed material including a dielectric material and a magnetic material.

Description

Specification

Antenna structure and wireless communication apparatus including the same

Technical field

The present invention relates to an antenna structure for performing wireless communication in a low frequency band and wireless communication in a high frequency band, and a wireless communication apparatus including the antenna structure. Background art

[0002] There is a wireless communication device having both a wireless communication function using a high frequency band and a wireless communication function using a low frequency band. For example, in a mobile phone, wireless communication of signals such as voice signals for calls and data signals such as video and text information is performed in a high frequency band such as about 800 MHz or more. In some cases, such a mobile phone is provided with a wireless communication function for a wireless ID system (RF—ID system), for example. In the wireless ID system, for example, wireless communication is performed in a low frequency band of about 13.56 MHz. In other words, a portable telephone that can support a wireless ID system has both a wireless communication function in a high frequency band and a wireless communication function in a low frequency band.

Patent Document 1: Japanese Patent Application Laid-Open No. 11 345518

Patent Document 2: JP 2000-339437 A

Patent Document 3: Japanese Patent Application Laid-Open No. 2004-173308

Disclosure of the invention

Problems to be solved by the invention

[0004] In a mobile phone having a wireless communication function in the low frequency band as described above, for example, an antenna 30 for a high frequency band as shown in Fig. 20a is provided, and for example, a pick-up coil or the like. An antenna for the low frequency band that also has power is provided.

[0005] An antenna 30 for a high frequency band shown in FIG. 20a has a state in which a radiation electrode 31 capable of performing an antenna operation at a resonance frequency in a high frequency band is provided on a dielectric substrate 32. is there. From the viewpoint of improving antenna characteristics, this high-frequency band antenna 30 has a circuit board edge that avoids the mounting area of other parts of the circuit board 34 provided in the mobile phone 33 as shown in FIG. 20b, for example. Provided in the section. [0006] Furthermore, the antenna for the low frequency band is constituted by a film-like spiral electrode 35 formed on the circuit board 34 as shown in FIG. 20b, for example. Since the spiral electrode 35 performs an antenna operation with a resonance frequency in the low frequency band, the spiral electrode 35 has a radiation electrode 31 for the high frequency band in order to have a resonance frequency in the low frequency band. Compared to, it is easy to enlarge.

However, with the miniaturization of the wireless communication device (mobile phone 33), the spiral electrode 35 for the low frequency band is required to be miniaturized. In addition, a reduction in the formation area of the antenna (radiating electrode) is also required. Furthermore, when the mobile phone 33 is a folding type, as shown in the schematic side view of FIG. 20c, when the mobile phone 33 is folded, another circuit board 34 is provided on one side of the circuit board 34. The circuit board 36 will be arranged. Since the other circuit board 36 is provided with components such as a liquid crystal panel 37, for example, the components of the circuit board 36 block the magnetic field generated from the spiral electrode 35 for the low frequency band and increase the antenna sensitivity. Deteriorate. In addition, a magnetic field of an external force is blocked by the components of the circuit board 36 and reaches the spiral electrode 35 for the low frequency band. Therefore, the spiral electrode 35 for the low frequency band has a problem that the antenna sensitivity on the circuit board 36 side is significantly worse than that of the spiral electrode 35.

Means for solving the problem

The present invention has the following configuration as means for solving the above problems. In other words, the antenna structure of the present invention is

A radiation electrode for a high frequency band that performs antenna operation with a resonance frequency of the high frequency band, and a base on which the radiation electrode for the high frequency band is provided,

In the space formed by partially lacking the substrate, there is a low frequency band antenna component equipped with a coil that functions as a radiation electrode for the low frequency band that performs antenna operation with a resonance frequency in the low frequency band. Arranged,

The radiating electrode for the high frequency band is formed on the base body so as to avoid the base part through which the high magnetic field of the magnetic flux density of the coil center portion of the low frequency band antenna component passes. It is characterized by being composed of a mixed material including a dielectric material and a magnetic material. [0009] The antenna structure of the present invention includes

A radiation electrode for a low frequency band that performs antenna operation with a resonance frequency in a low frequency band, a radiation electrode for a high frequency band that performs antenna operation with a resonance frequency in a high frequency band, the radiation electrode for the low frequency band, and the high frequency A substrate on which both radiation electrodes for the band are provided,

Have

The substrate is also characterized by being composed of a mixed material including a dielectric material and a magnetic material.

[0010] Furthermore, the antenna structure of the present invention includes:

An antenna structure in which a substrate including a radiation electrode for a high frequency band that performs antenna operation at a resonance frequency of a high frequency band is mounted on a printed circuit board,

A coiled radiation electrode for a low frequency band that performs an antenna operation with a resonance frequency in a low frequency band is formed in the printed circuit board area on which the substrate is mounted. The base having the radiation electrode for the high frequency band is laminated on the upper side.

The high frequency band radiation electrode is formed on the base body avoiding the high magnetic field of the magnetic flux density at the center of the coil of the coiled low frequency band radiation electrode.

The substrate is characterized in that it is made of a mixed material including a dielectric material and a magnetic material.

Furthermore, the wireless communication apparatus of the present invention is characterized in that an antenna structure having a configuration unique to the present invention is provided.

The invention's effect

[0012] According to the present invention, the base on which the radiation electrode for the high frequency band is formed is made of a mixed material including a dielectric material and a magnetic material. The dielectric material of the mixed material constituting the substrate has a specific dielectric constant almost constant regardless of the frequency. Have sex. In contrast, magnetic materials have a high relative permeability for frequencies in the low frequency band, and are low for frequencies in the high frequency band, for example, a relative permeability (for example, close to approximately 1, relative permeability). It has something. The inventor paid attention to the characteristics of the magnetic material.

[0013] That is, by appropriately adjusting the mixing ratio of the dielectric material and the magnetic material according to the characteristics of the magnetic material, the base made of the mixed material containing the dielectric material and the magnetic material is In the low frequency band, it can be treated as a magnetic material (although the characteristics of the dielectric material are not weakened) due to the magnetic permeability of the magnetic material. In addition, the magnetic material has a magnetic permeability of almost 1 in the high-frequency band, so it can be handled as a dielectric. For this reason, the base material behaves as a magnetic base material with a stronger characteristic based on the relative magnetic permeability of the magnetic material than the relative dielectric constant of the dielectric material for frequencies in the low frequency band. In addition, the substrate behaves as a dielectric substrate for a frequency in a high frequency band because the characteristics based on the relative permittivity of the dielectric material are stronger than the relative permeability of the magnetic material. The substrate constituting the antenna structure of the present invention can have the above-mentioned specific characteristics by being composed of a mixed material including a dielectric material and a magnetic material.

[0014] In the present invention, the radiation electrode for the low frequency band is formed in a space disposed in the absence of the base part, or is formed on the base body together with the radiation electrode for the high frequency band. Or is formed in a substrate mounting area of a printed circuit board on which the substrate is mounted. In other words, the substrate is arranged in a part of the path of the magnetic field generated from the radiation electrode for the low frequency band. In other words, according to the present invention, the base can be configured to behave as a magnetic substrate for frequencies in the low frequency band, so that part of the magnetic field of the radiation electrode for the low frequency band passes through the magnetic material. It can be. By adopting a configuration in which the magnetic field passes through the magnetic material in this way, it is possible to reduce the size of the radiation electrode for the low frequency band. In addition, since the radiation electrode for the low frequency band is reduced in size, the substrate on which the radiation electrode for the high frequency band is formed can be provided with the small radiation electrode for the low frequency band, A radiation electrode for a low frequency band can be disposed so as to be within the mounting region of the substrate. Thereby, for example, the formation area of the radiation electrode for the low frequency band in the circuit board of the wireless communication device can be reduced.

[0015] Further, since the radiation electrode for the low frequency band can be reduced in size, A radiation electrode for a low frequency band can be disposed at the edge of the circuit board built in the line communication device. By arranging the radiation electrode for the low frequency band at the edge part of the circuit board, the magnetic field generated by the components mounted on the circuit board out of the magnetic field generated by the radiation electrode cover for the low frequency band. Decrease. As a result, the antenna sensitivity of the radiation electrode for the low frequency band can be improved.

[0016] Further, when the radiation electrode for the low frequency band is formed in a coil shape and the radiation electrode for the low frequency band and the radiation electrode for the high frequency band are laminated, the high frequency band The radiation electrode for the frequency band is designed for the low frequency band by having a structure that is formed on the substrate avoiding the base part through which the magnetic field with high magnetic flux density passes through the center of the coil of the radiation electrode for the low frequency band. Magnetic field force with a high magnetic flux density of the radiation electrode The situation of being blocked by the radiation electrode for the high frequency band can be avoided. As a result, the radiation electrode for the low frequency band and the radiation electrode for the high frequency band are arranged close to each other! Therefore, it is possible to suppress the deterioration of the antenna characteristics of the radiation electrode for the low frequency band.

[0017] Further, in the wireless communication device provided with the antenna structure of the present invention, the wireless communication device can be downsized by downsizing the antenna structure. In addition, it is possible to expand the arrangement space of components other than the antenna in the wireless communication device. Further, when it is desired that the antenna sensitivity of the low frequency band radiation electrode is good and the direction is expanded, the antenna structure of the present invention is provided at the edge portion of the circuit board, so that the low frequency band is provided. Among the magnetic fields radiated from the radiation electrode cover, the magnetic field blocked by the circuit board components can be reduced. As a result, the direction of good antenna sensitivity of the radiation electrode for the low frequency band can be expanded.

Brief Description of Drawings

FIG. 1 is a model diagram for explaining an antenna structure of a first embodiment.

FIG. 2 is a graph for explaining an example of frequency characteristics of relative permittivity of a dielectric material and frequency characteristics of relative permeability of a magnetic material.

FIG. 3a is a model diagram showing a configuration example of an antenna component for a low frequency band.

FIG. 3b is a model diagram showing another configuration example of the antenna component for the low frequency band.

FIG. 3c is a model diagram showing still another configuration example of the antenna component for low frequency band. [4a] It is an exploded view for explaining a configuration example of the antenna component for the low frequency band shown in FIG. 4b.

FIG. 4b is a model diagram showing another configuration example of the antenna component for the low frequency band.

FIG. 5a is a model diagram showing another configuration example of the antenna component for the low frequency band.

FIG. 5b is a model diagram showing another configuration example of the antenna component for the low frequency band.

[Fig. 6] Furthermore, it is a model diagram showing another configuration example of the antenna component for the low frequency band. 圆 7] A diagram for explaining one of the obtained effects of the antenna structural force of the first embodiment.

FIG. 8 is a model diagram showing another arrangement example of antenna components for low frequency band.

FIG. 9 is a model diagram showing an example of another arrangement posture of antenna components for low frequency band.

FIG. 10a is a diagram for explaining another example of the radiation electrode for the high frequency band.

FIG. 10b is a cross-sectional side view of the high-frequency band radiation electrode shown in FIG. 10a.

[11a] It is a diagram for explaining the antenna structure of the second embodiment.

[11] ib] is a model diagram showing an example of a substrate constituting the antenna structure of the second embodiment.

[11c] FIG. 11c is a model diagram showing another embodiment of the base body constituting the antenna structure of the second embodiment.

[Lid] is a model diagram showing still another embodiment of the substrate constituting the antenna structure of the second embodiment.

[12] FIG. 12 is a diagram for explaining an antenna structure of a third embodiment.

13a] is a model diagram showing an example of the shape of the hole for lowering the effective magnetic permeability in the region where the radiation electrode for the high frequency band is formed on the substrate.

13b] is a model diagram showing another example of the shape of the hole for lowering the effective magnetic permeability of the region where the radiation electrode for the high frequency band is formed on the base.

13c] A model diagram showing still another example of the shape of the hole for lowering the effective magnetic permeability of the formation region of the radiation electrode for the high frequency band in the base. FIG. 13D is a model diagram showing still another embodiment of the hole for lowering the effective permeability of the formation region of the radiation electrode for the high frequency band in the base.

FIG. 14a is a model diagram showing a modification of the antenna structure shown in FIG.

FIG. 14b is a model diagram showing another modification of the antenna structure shown in FIG. [15a] This is a model diagram showing an example of an inverted F-type radiation electrode for a high-frequency band.

[15b] This is a model diagram showing an example of an inverted F type high-frequency radiation electrode.

FIG. 16a is a model diagram showing an example of a line-shaped high-frequency band radiation electrode.圆 16b] is a model diagram showing another form of the radiation electrode for the line-shaped high frequency band. 圆 17] is a diagram for explaining the antenna structure of the fourth embodiment.

[18] FIG. 18 is a drawing for explaining the antenna structure of the fifth embodiment.

FIG. 19a is a diagram for explaining another embodiment.

FIG. 19b is a diagram for explaining still another embodiment.

FIG. 20a is a diagram for explaining a conventional problem.

FIG. 20b is a diagram for explaining the conventional problem together with FIG. 20a.

FIG. 20c is a diagram for explaining a conventional problem together with FIGS. 20a and 20b.

Explanation of symbols

1 Antenna structure

2 Circuit board

3 Substrate

4 Radiation electrode for high frequency band

5 Antenna components for low frequency band

25 Radiation electrode for low frequency band

26 holes

27 Base

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic perspective view of the antenna structure of the first embodiment. The antenna structure 1 of the first embodiment includes a substrate 3 mounted on a circuit board 2 that is a printed circuit board, and a high frequency band radiation electrode 4 (4A, 4B) that performs antenna operation at a resonance frequency of the high frequency band. And a low-frequency band antenna component 5 having a radiation electrode that performs antenna operation with a resonance frequency in a low-frequency band.

[0022] In the first embodiment, the base body 3 has an aspect in which a rectangular parallelepiped bottom surface side is partially absent to form a cross-sectional shape and a square shape. The substrate 3 is made of a mixed material in which a dielectric material and a magnetic material are mixed with a resin material. The substrate 3 is produced by a molding technique such as injection molding. Since the base body 3 is produced by the molding technique, the base body 3 can be easily manufactured.

[0023] As shown by a chain line | 8 in the graph of FIG. 2, the dielectric material has a characteristic that the relative dielectric constant is constant regardless of the change in frequency. On the other hand, as shown by the solid line α in the graph of FIG. 2, the magnetic material has a high saturation state that gradually increases as the frequency decreases with respect to the low frequency band. Has relative permeability. In addition, the magnetic material has a substantially stable low relative permeability (for example, a relative permeability of about 1) that gradually decreases as the frequency increases with respect to the frequency in the high frequency band. In addition, in the magnetic material, the relative permeability rapidly decreases as the frequency increases within the frequency range between the low frequency band having a high relative permeability and the high frequency band having a low relative permeability. It has a characteristic part with an inflection point.

[0024] In the first embodiment, the substrate 3 is configured with attention paid to the characteristics of the magnetic material described above. In order for the base 3 to have the following characteristics, a dielectric material or a magnetic material is selected as a constituent material of the base 3, and a mixing ratio of the dielectric material and the magnetic material is set. ing. In other words, the low frequency band antenna component 5 is based on the relative permeability of the magnetic material rather than the relative dielectric constant of the dielectric material for frequencies in the low frequency band including the resonance frequency (for example, 13.56 MHz) at which the antenna operates. As a result, the characteristics are so strong that the substrate 3 behaves as a magnetic substrate. Also, the high frequency band radiation electrode 4 (4A, 4B) has a high frequency band including a resonance frequency (for example, a frequency of 800 MHz or more) at which the antenna operation is performed. With respect to the frequency, the characteristics based on the relative permittivity of the dielectric material are stronger than the relative permeability of the magnetic material, and the substrate 3 behaves as a dielectric substrate. In this first embodiment, the substrate 3 can behave as a magnetic substrate for such a low frequency band frequency, and can behave as a dielectric substrate for a high frequency band frequency. In addition, a dielectric material, a magnetic material, and a mixing ratio of the dielectric material and the magnetic material are set.

[0025] In the first embodiment, the base body 3 has a form in which a part on the bottom side is partially absent, and a space 6 is formed in the lack part. The base body 3 is mounted on an edge portion on one end side of the circuit board 2 in such a posture that the space 6 is on the circuit board 2 side. The antenna component 5 for the low frequency band is provided on the circuit board 2 so as to be disposed in the space 6 formed in the lacking portion of the base 3. The antenna component 5 for low frequency band is used in a radio communication system using a low frequency band such as a radio ID system. The low-frequency band antenna component 5 includes a coil that functions as a radiation electrode for a low-frequency band that performs an antenna operation with a predetermined resonance frequency in the low-frequency band.

In the first embodiment, the antenna component 5 for low frequency band has a small size that can be placed in the space 6 of the base 3 and performs antenna operation at the set resonance frequency. If it has a configuration that can be used, the configuration is not particularly limited, and can take various forms. For example, the low-frequency band antenna component 5 may have a configuration in which a coil pattern 11 as a low-frequency band radiation electrode is formed on the upper surface of the magnetic substrate 10, as shown in FIG. 3a. Further, as shown in FIG. 3b, the low-frequency band antenna component 5 may have a configuration in which a coil pattern 11 as a low-frequency band radiation electrode is formed across a plurality of surfaces of the magnetic substrate 10. Good. Furthermore, in the low frequency band antenna component 5, as shown in FIG. 3c, a coil pattern 11 as a radiation electrode for the low frequency band is formed on the upper surface of the magnetic substrate 10, and an upper side of the coil pattern 11 is formed. A configuration in which the dielectric film 12 is laminated and formed.

[0027] Further, in the antenna component 5 for low frequency band, the coil pattern 13 as shown in Fig. 4a and the magnetic layer (not shown) are alternately stacked, and as shown in Fig. 4b, Integrated It may be configured as described above. The plurality of coil patterns 13 are electrically connected in series by via holes formed in the magnetic layer to constitute one coil.

[0028] Further, the low frequency band antenna component 5 may have a configuration in which the conductive wire 14 is wound in a coil shape, as shown in FIG. 5a. Further, as shown in FIG. 5b, the low-frequency band antenna component 5 has a configuration in which a core 15 having a magnetic material force such as ferrite is arranged at the center of a coil formed by winding a conductive wire 14 in a coil shape. It is good. Furthermore, the low frequency band antenna component 5 may have a configuration in which a conducting wire 17 is formed on the circumferential surface of the magnetic substrate 16 as shown in FIG.

In the first embodiment, any of the various configurations as described above may be adopted as the configuration of the antenna component 5 for the low frequency band. In this first embodiment, the antenna component 5 for low frequency band is such that the magnetic field having a high magnetic flux density at the center of the coil of the antenna component 5 for low frequency band is substantially orthogonal to the substrate surface of the circuit board 2 and the upper surface of the substrate 3. It is fixed to the circuit board 2 with its posture.

[0030] In the first embodiment, the radiation electrode 4 for the high frequency band can be used for a radio communication system using a high frequency band such as a radio communication of an audio signal or a data signal of a mobile phone. is there. The radiation electrode 4 for the high frequency band can perform an antenna operation at a predetermined resonance frequency in the high frequency band, and a magnetic field having a high magnetic flux density at the center of the coil of the antenna component 5 for the low frequency band. The configuration is not particularly limited as long as the configuration is formed in the upper surface region of the substrate that avoids the passing portion, but an example of the configuration is shown in FIG. In the example of FIG. 1, the radiation electrode 4 for the high frequency band includes a power supply radiation electrode 4A and a parasitic radiation electrode 4B. Radiation electrodes 4A and 4B are λ Z4 type radiation electrodes. The feed radiation electrode 4 例えば is connected to a radio communication high frequency circuit 18 provided in a radio communication device, for example, and performs an antenna operation. The parasitic radiation electrode 4Β is electromagnetically coupled to the feeding radiation electrode 4Α and resonates with the resonance operation of the feeding radiation electrode 4Α to create a double resonance state. In this way, the feed radiation electrode 4 給電 and the non-feed radiation electrode 4 形成 are formed so that a double resonance state can be created, thereby utilizing the effect of widening the frequency band and different frequency bands. The effect of being able to support multiple wireless communication systems and the antenna gain Improvement effects and the like can be obtained.

In the first embodiment, as described above, the base 3 is made of a mixed material including a dielectric material and a magnetic material. As a result, the substrate 3 is configured to behave as a magnetic substrate for frequencies in the low frequency band and to behave as a dielectric substrate for frequencies in the high frequency band. That is, the substrate 3 is a dielectric substrate when viewed from the radiation electrode 4 for the high frequency band, and is a magnetic substrate when viewed from the antenna component 5 for the low frequency band. For this reason, as shown in the first embodiment, the low frequency band antenna component 5 is arranged so that a magnetic field having a high magnetic flux density in the center of the coil of the low frequency band antenna component 5 passes through the base 3. Therefore, the antenna component 5 for low frequency band can be downsized by the wavelength shortening effect of the magnetic material. In the first embodiment, since the antenna component 5 for low frequency band can be reduced in size, the antenna component 5 for low frequency band can also be mounted in the mounting region of the substrate 3 on the circuit board 2. As a result, the antenna mounting area required for mounting the antenna on the circuit board 2 can be reduced.

Furthermore, in the first embodiment, the high-frequency band radiation electrode 4 (4A, 4B) avoids a portion through which a magnetic field having a high magnetic flux density passes at the center of the coil of the low-frequency band antenna component 5. It is formed. Therefore, it is possible to prevent the magnetic field (radio wave) of the antenna component 5 for the low frequency band from being disturbed by the radiation electrode 4 for the high frequency band. For this reason, it is possible to suppress bad antenna characteristics of the antenna component 5 for the low frequency band due to the close arrangement of the radiation electrode 4 for the high frequency band.

[0033] By placing the antenna structure 1 at the edge of the circuit board that avoids the mounting area of the circuit component on the circuit board 2, the antenna component 5 for the low frequency band is Compared with the case where it is mounted on a portion other than the edge portion, the directivity of the magnetic field (radio wave) radiation of the antenna component 5 for the low frequency band can be expanded. For example, when the antenna structure 1 in the first embodiment is provided in a foldable portable telephone, the antenna structure 1 is provided at the edge portion of the circuit board 2 as shown in the side view of FIG. As a result, the magnetic field of the antenna component 5 for the low frequency band can spread in the vertical direction in FIG. 7 without being blocked by the component 20 such as a liquid crystal panel. Thus, the antenna sensitivity of the antenna component 5 for low frequency band can be improved. [0034] It should be noted that the antenna component 5 for the low frequency band is within the mounting region of the base 3 on the circuit board 2, and the circuit of the circuit board 2, the radiation electrode 4 for the high frequency band, and the antenna component 5 for the low frequency band. The location of the antenna component 5 for the low frequency band, which is arranged at an appropriate position in consideration of the configuration of the wiring connecting the radiating electrode and the configuration of the radiation electrode 4 for the high frequency band, etc., is the position shown in FIG. It is not limited to. For example, as shown in FIG. 8, the antenna component 5 for low frequency band may be arranged so that a magnetic flux having a high magnetic flux density in the center of the coil passes through the corner of the base 3. In the first embodiment, the low frequency band antenna component 5 has a posture in which a magnetic field having a high magnetic flux density at the center of the coil of the component 5 is substantially orthogonal to the substrate surface of the circuit board 2 and the upper surface of the substrate 3. For example, as shown in FIG. 9, the antenna component 5 for the low frequency band has a magnetic field with a high magnetic flux density at the center of the coil so that it substantially follows the board surface of the circuit board 2 and the upper surface of the base 3. You may arrange | position with a various attitude | position. In this case, the magnetic field having a high magnetic flux density at the center of the coil of the antenna component 5 for low frequency band does not pass through the upper surface of the substrate 3. For this reason, when the radiation electrode 4 for the high frequency band is formed on the upper surface of the substrate 3, the restriction of the formation region of the radiation electrode 4 for the high frequency band by the antenna component 5 for the low frequency band is relaxed. As a result, the degree of freedom in designing the radiation electrode 4 for the high frequency band can be increased.

Further, in the example of FIG. 1, the base body 3 is configured to have a cross-sectional force-fitting shape. For example, as shown in FIG. 9, the base body 3 has a recess 21 on the bottom surface side. In other words, a space portion for accommodating the antenna component 5 for the low frequency band may be provided.

Furthermore, the antenna structure 1 may be configured as shown in the perspective view of FIG. 10a and the sectional side view of FIG. 10b. That is, in the antenna structure 1, the radiation electrode 4 (4A, 4B) has a loop shape. That is, the radiation electrode 4 (4A, 4B) is formed to extend from the edge of the circuit board 2 to the outer region of the circuit board 2 while bulging downward from the circuit board 2, and then the end surface of the circuit board 2 with a space therebetween. The circuit board 2 is formed to wrap around and extend to the upper surface side of the circuit board 2, and the extended distal end side is arranged on the upper surface of the circuit board 2 with a gap. A base 3 made of a mixed material including a dielectric material and a magnetic material is formed on a part of the radiation electrode 4 (4A, 4B). Also, mounting the base 3 on the circuit board 2 In the region, the antenna component 5 for the low frequency band is arranged in a portion that cannot be seen as a shadow of the radiation electrode 4 in FIG. 10a.

[0037] The second embodiment will be described below. In the description of the second embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and the duplicate description of the common portions is omitted.

[0038] The second embodiment is characterized by the form of the substrate 3. The other configuration of the antenna structure 1 is the same as that of the first embodiment. That is, from the viewpoint of improving the antenna characteristics of the low-frequency band antenna component 5, the thickness of the portion of the base 3 through which the magnetic field having a high magnetic flux density at the center of the coil of the low-frequency band antenna component 5 passes is thick. Is preferred. On the other hand, when viewed from the radiation electrode 4 for the high frequency band, since the magnetic material is contained in the substrate 3, magnetic material loss due to the magnetic material of the substrate 3 occurs. For this reason, it is preferable that the substrate 3 is thin. In consideration of this, in the second embodiment, the base 3 has a thickness of the portion of the base 3 through which a magnetic field having a high magnetic flux density in the center part of the coil of the low frequency band antenna component 5 passes. It has a form that is thicker than the average thickness of the region where the radiation electrode 4 is formed.

[0039] As a specific example, for example, the low-frequency band antenna component 5 is positioned in the position of the circuit board 2 as shown in Fig. 11a (that is, the circuit in the predetermined substrate mounting region in the circuit board 2). In the case where the substrate 3 is disposed on the edge near the center of the substrate 2, the base 3 may take a form as shown in FIGS. That is, in the example of FIG. 11a, the base 3 is continuously thickened according to the direction force from one side 3b to the other side 3a of the opposing edge portions 3a, 3b, and the top surface of the base is relative to the bottom surface of the base. It is formed in a form that tilts and rises. The substrate 3 is mounted on the edge portion of the circuit board 2 so that the thin portion is disposed on the edge portion on one end side of the circuit board 2 and the thick portion is disposed on the arrangement side of the antenna component 5 for the low frequency band. It is done. A recess (not shown) is provided on the bottom surface side of the base 3 for forming a space for accommodating and arranging the antenna component 5 for low frequency band.

[0040] In the example of Fig. L ib, the substrate 3 has a substantially hill-like form. A concave portion (not shown) for forming a space for accommodating and arranging the antenna component 5 for low frequency band is provided on the bottom surface side of the portion where the thickness of the base 3 is the thickest.

[0041] In the example of FIG. 11c, the base 3 protrudes from the region where the low frequency band antenna component 5 is disposed. The portion 22 is formed so that the thickness of the base portion is increased. A recess (not shown) for forming a space for accommodating and arranging the low frequency band antenna component 5 is provided on the bottom surface side of the portion where the thickness of the base 3 is increased. In the example of the exploded view of id in Fig. L, the base 3 is hollow in the area avoiding the area where the low-frequency band antenna component 5 is disposed, and the base in the area where the low-frequency band antenna component 5 is disposed The thickness of the part has increased substantially. A recess (not shown) for forming a space for accommodating and arranging the low-frequency band antenna component 5 is provided on the bottom surface side of the substrate in the region where the low-frequency band antenna component 5 is disposed.

[0042] In the second embodiment, the base 3 has a configuration in which the magnetic flux density at the center of the coil of the antenna component 5 for low frequency band is high and the thickness of the portion through which the magnetic field passes can be increased. . As a result, the length of the base portion (that is, the magnetic base portion) through which the magnetic field having a high magnetic flux density passes in the central portion of the coil of the antenna component 5 for low frequency band is increased. For this reason, the effect of shortening the wavelength by the magnetic material is increased, so that it is possible to further reduce the size of the low-frequency band antenna component 5 and improve the antenna sensitivity. In addition, since the base portion of the formation region of the radiation electrode 4 for the high frequency band can be made thin, the magnetic material loss of the radiation electrode 4 for the high frequency band due to the magnetic material of the base body 3 can be reduced. Thereby, the antenna characteristics of the radiation electrode 4 for the high frequency band can be improved. In such a case, in order to reduce the magnetic material loss of the radiation electrode 4 for the high-frequency band, when the base portion where the radiation electrode 4 for the high-frequency band is formed is made thin, Due to this configuration, there is a concern that the wavelength shortening effect of the substrate 3 on the radiation electrode 4 for the high frequency band is reduced. Therefore, in order to prevent the wavelength shortening effect of the base 3 on the radiation electrode 4 for the high frequency band from being reduced, for example, a dielectric material having a high relative dielectric constant is used as the dielectric material contained in the base 3. I prefer to take measures.

[0043] A third embodiment will be described below. In the description of the third embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals, and overlapping description of the common portions is omitted.

In the third embodiment, as shown in FIG. 12, both the high frequency band radiation electrode 4 (4A, 4B) and the low frequency band radiation electrode 25 are provided on the substrate 3. Yes. That is, The substrate 3 is made of a mixed material containing a dielectric material and a magnetic material, as in the first and second embodiments. In the left region of FIG. 12 on the upper surface of the substrate 3, a radiation electrode 4 for a high frequency band having a feed radiation electrode 4A and a parasitic radiation electrode 4B is formed. In the right region of FIG. 12 on the upper surface of the substrate 3, a radiation electrode (coil electrode) 25 for a low frequency band made up of a coil pattern cover and a radiation electrode 4 for a high frequency band is formed. The structure of the antenna structure 1 other than these structures is the same as in the first and second embodiments.

In the third embodiment, both the high-frequency band radiation electrode 4 and the low-frequency band radiation electrode 25 are provided on a common base 3 to form a single component. For this reason, for example, the base 3 provided with both the radiation electrode 4 for the high frequency band and the radiation electrode 25 for the low frequency band is simply disposed in the mounting region of the setting of the circuit board 2 of the wireless communication device. The antenna structure 1 can be provided on the circuit board 2. Thereby, for example, the manufacturing process of the wireless communication device can be simplified.

By the way, when the radiation electrode 4 for the high frequency band is formed on the base 3 containing the magnetic material, the magnetic material causes a magnetic loss. For this reason, in order to reduce the magnetic material loss of the radiation electrode 4 for the high frequency band, a configuration in which the effective permeability of the base portion on which the radiation electrode 4 for the high frequency band is formed may be provided. For example, as shown in FIGS. 13a to 13d, a hole portion (or a hollow portion) 26 for reducing the effective magnetic permeability is provided in the base portion where the radiation electrode 4 for the high frequency band is formed. That is, in the example of FIG. 13a, a recess (having openings on both the front end face and the rear end face shown in FIG. 13a of the base 3 on the bottom surface of the base portion where the radiation electrode 4 for the high frequency band is formed. Groove (hole)) 26 is provided. In the example of FIG. 13b, a hole (through hole) 26 penetrating from the front end surface side to the rear end surface side of the substrate 3 shown in FIG. It has been. In the example of FIG. 13c, a hole portion 26 having an opening on the left side surface shown in FIG. 13c of the base 3 is provided in the base portion where the radiation electrode 4 for the high frequency band is formed. In the example of FIG. 13d, a recess (hole (recessed portion)) 26 having an opening is formed on the bottom surface of the base portion where the radiation electrode 4 for the high frequency band is formed. Thus, the hole 26 is formed in the base portion where the radiation electrode 4 for the high frequency band is formed. As a result, A configuration may be provided in which the magnetic permeability of the radiation electrode 4 for the high frequency band is reduced by lowering the effective permeability of the base portion on which the radiation electrode 4 for the wave band is formed. By providing such a configuration, the antenna characteristics of the radiation electrode 4 for the high frequency band can be improved.

Further, for example, a step is provided on the upper surface of the base 3 so that the formation region of the high-frequency band radiation electrode 4 on the upper surface of the base 3 is lower than the formation region of the low-frequency band radiation electrode 25. As a configuration, the thickness of the portion of the base 3 where the radiation electrode 4 for the high frequency band is formed may be thinner than the portion of the base 3 where the radiation electrode 25 for the low frequency band is formed. . By adopting such a configuration, there may be provided a configuration in which the magnetic permeability of the radiation electrode 4 for the high frequency band is reduced by lowering the effective permeability of the base portion where the radiation electrode 4 for the high frequency band is formed. . By providing such a configuration, it is possible to improve the antenna characteristics of the radiation electrode 4 for the high frequency band.

[0048] In the examples shown in Fig. 12 and Figs. 13a to 13d, both the high-frequency band radiation electrode 4 and the low-frequency band radiation electrode 25 are formed on the upper surface of the substrate 3. The radiation electrode 4 for the high frequency band and the radiation electrode 25 for the low frequency band may be formed on different surfaces of the substrate 3, respectively. For example, in the example shown in FIG. 14a, the radiation electrode 4 for high frequency band is formed on the upper surface of the substrate 3, and the radiation electrode 25 for low frequency band is formed on the side surface of the substrate 3. In this way, the size of the substrate 3 can be increased by adopting a configuration in which the radiation electrode 4 for the high frequency band and the radiation electrode 25 for the low frequency band are respectively formed on different surfaces of the substrate 3. In addition, the electrode area of the radiation electrode 4 for the high frequency band and the radiation electrode 25 for the low frequency band can be increased. As a result, the frequency band of the radiation electrode 4 for the high frequency band and the radiation electrode 25 for the low frequency band can be widened, and the antenna characteristics can be improved. In the example of FIG. 14a, the radiation electrode 25 for the low frequency band is formed such that a magnetic field having a high magnetic flux density at the center of the coil of the radiation electrode 25 for the low frequency band is along the upper surface of the substrate 3. For this reason, the radiation electrode 4 for the high frequency band formed on the upper surface of the substrate 3 is designed so as not to worry about the path of the magnetic field having a high magnetic flux density at the center of the coil of the radiation electrode 25 for the low frequency band. be able to. That is, the design freedom of the radiation electrode 4 for the high frequency band can be increased. In addition, as shown in FIG. 14b, one or both of the radiation electrode 4 for the high frequency band and the radiation electrode 25 for the low frequency band are formed over a plurality of surfaces of the substrate 3. It is good also as the structure which has. By providing this configuration, it is possible to increase the electrode area of the radiation electrode 4 for the high frequency band and the radiation electrode 25 for the low frequency band. As a result, the frequency band of the radiation electrode 4 for the high frequency band and the radiation electrode 25 for the low frequency band can be widened, and the antenna characteristics can be improved.

[0050] Further, in the examples shown in Fig. 12 and Figs. 13a to 13d, the radiation electrode 4 for the high frequency band is a force that was a λZ4 type radiation electrode. For example, as shown in Figs. 15a and 15b, The radiation electrode 4 for the high frequency band may be an inverted F type radiation electrode. Further, a linear radiation electrode as shown in FIG. 16a or FIG. 16b may be used. In the examples of FIGS. 15a, 16a, and 16b, the radiation electrode 25 for the low frequency band is formed on the upper surface of the substrate 3. In the example of FIG. 15b, the radiation electrode for the low frequency band is formed by alternately laminating a coil pattern as shown in FIG. 4a and an insulating layer made of a mixed material including a dielectric material and a magnetic material. It is formed as a single unit.

[0051] The fourth embodiment will be described below. In the description of the fourth embodiment, the same components as those in the first to third embodiments will be denoted by the same reference numerals, and overlapping description of the common portions will be omitted.

In the fourth embodiment, as shown in the exploded view of FIG. 17, the radiating electrode 4 for the high frequency band is formed on the base 3 made of a mixed material containing a dielectric material and a magnetic material. ing. A coil-shaped radiation electrode 25 for a low frequency band is formed on a portion of the circuit board 2 on which the base 3 on which the radiation electrode 4 for the high frequency band is formed is mounted. That is, the base 3 having the high-frequency band radiation electrode 4 is laminated on the upper side of the low-frequency band radiation electrode 25 formed on the circuit board 2.

Also in the fourth embodiment, as in each of the above embodiments, high frequency band radiation is avoided as much as possible by avoiding a base portion through which a magnetic field having a high magnetic flux density at the center of the coil of the radiation electrode 25 for low frequency band passes. An electrode 4 is formed on the substrate 3.

[0054] A fifth embodiment will be described below. In the description of the fifth embodiment, the same components as those in the first to fourth embodiments are denoted by the same reference numerals, and the overlapping description of the common portions is omitted. To do.

In the fifth embodiment, as shown in the exploded view of FIG. 18, the radiation electrode 4 for the high frequency band is formed on the base 3 made of a mixed material containing a dielectric material and a magnetic material. ing. The radiation electrode 25 for the low frequency band is formed on, for example, a film-like base body 27 having, for example, a resin material strength. The base body 3 on which the high-frequency band radiation electrode 4 is formed and the base body 27 on which the low-frequency band radiation electrode 25 is formed are integrated into a single component. As shown in FIG. 18, in the fifth embodiment as well, in the same way as in each of the embodiments described above, the path of the magnetic field having a high magnetic flux density at the center of the coil of the radiation electrode 25 for the low frequency band is not obstructed. The high-frequency band radiation electrode 4 is formed on the substrate 3 while avoiding the base portion through which a magnetic field having a high magnetic flux density passes through the center of the coil of the low-frequency band radiation electrode 25.

[0056] In the example shown in Fig. 18, the force that the radiation electrode 25 for the low frequency band is formed on the upper surface of the base 27. For example, the radiation electrode 25 for the low frequency band includes a plurality of the base 27 It may be formed across the surface. Further, instead of forming the low-frequency band radiation electrode 25 on the film-like substrate 27 made of a resin material, the low-frequency band radiation electrode 25 is formed on a substrate made of a magnetic material cover. It is good also as a structure to be. Furthermore, a plurality of coil patterns constituting a low frequency band radiation electrode as shown in FIG. 4 are integrated with each other through a magnetic layer, and the low frequency band radiation electrode is formed inside the substrate. It may be in the form of being formed. Further, the radiation electrode for the low frequency band is the same as the antenna component 5 for the low frequency band as shown in the first embodiment, and the antenna component for the low frequency band is fixed to the base 27, The base body 3 on which the high-frequency band radiation electrode 4 is formed may be laminated and integrated on the upper side of the base body 27 to which the frequency band antenna component 5 is fixed. In this case, a space for accommodating the antenna component 5 for the low frequency band is formed on the bottom surface side of the base 3 without a part thereof. Thus, the form of the radiation electrode for the low frequency band constituting the antenna structure 1 of the fifth embodiment is not particularly limited.

[0057] The sixth embodiment will be described below. The sixth embodiment relates to a wireless communication apparatus. The wireless communication device of this sixth embodiment has a wireless communication function in a low frequency band and a high frequency band. It has a configuration capable of performing both the wireless communication function and the wireless communication function. In the sixth embodiment, any one of the antenna structures 1 shown in the first to fifth embodiments is provided. There are various configurations other than the antenna structure in the wireless communication apparatus, and here, any configuration may be adopted and the description thereof is omitted. In addition, since the description of the antenna structure 1 of the first to fifth embodiments has been described above, the overlapping description is omitted here.

It should be noted that the present invention is not limited to the forms of the first to sixth embodiments, and can take various forms. For example, the base 3 is composed of a mixed material in which a dielectric material and a magnetic material are mixed with a resin material. However, the constituent material of the base 3 may be a mixed material including a dielectric material and a magnetic material. For example, it may be a mixed material of only a dielectric material and a magnetic material.

[0059] In each of the first to sixth embodiments, the high-frequency band radiation electrode 4 is formed on the base 3. For example, as shown in FIGS. 19a and 19b, the high-frequency band radiation electrode 4 is formed. The radiation electrode 4 may have a configuration in which a part of the radiation electrode 4 is drawn from the base 3 to the circuit board 2 which is a printed board. Although not shown in the examples of FIGS. 19a and 19b, the low frequency band antenna component 5 and the coiled radiation electrode 25 for the low frequency band are formed in the mounting region of the base 3 on the circuit board 2. Has been.

[0060] Further, when the radiation electrode 25 for the low frequency band is formed on the base 3, the radiation electrode 25 for the low frequency band is part of the circuit board 2 from the base 3 to the printed board. The bow I is formed and the structure is as follows.

Furthermore, in addition to the configurations of the first to sixth embodiments, a dielectric film that covers at least a part of the radiation electrode 4 for the high frequency band may be provided. Thus, by providing the dielectric film on the radiation electrode 4 for the high frequency band, the wavelength shortening effect by the dielectric increases, and the radiation electrode 4 for the high frequency band can be further downsized. it can.

Industrial applicability

[0062] In the present invention, the antenna for the low frequency band can be miniaturized when the antenna for the high frequency band and the antenna for the low frequency band are provided. For this reason, it is incorporated into wireless communication devices such as portable wireless communication devices that are required to be miniaturized. It is effective to apply the present invention to an antenna structure and a wireless communication apparatus.

Claims

The scope of the claims

[1] A radiation electrode for a high frequency band that performs antenna operation with a resonance frequency in the high frequency band, and

And a substrate on which the radiation electrode for the high frequency band is provided,

The radiating electrode for the high frequency band is formed on the base body so as to avoid the base part through which the high magnetic field of the magnetic flux density of the coil center portion of the low frequency band antenna component passes. An antenna structure comprising a mixed material including a dielectric material and a magnetic material.

[2] The antenna structure according to claim 1, wherein the base is configured to be mounted on a printed circuit board, and a part of the radiation electrode for a high frequency band is formed to be pulled out on the printed circuit board. .

[3] A radiation electrode for a low frequency band that performs an antenna operation with a resonance frequency in a low frequency band, a radiation electrode for a high frequency band that performs an antenna operation with a resonance frequency in a high frequency band, and the radiation electrode for the low frequency band described above A substrate on which both the high-frequency band radiation electrodes are provided; and

Have

An antenna structure characterized in that the substrate is made of a mixed material including a dielectric material and a magnetic material.

[4] The base portion on which the radiation electrode for the high-frequency band is formed is provided with a hole or a hollow portion for controlling the effective permeability of the base portion. Antenna structure.

[5] The radiation electrode for the low frequency band is composed of a coil electrode, and one or both of the radiation electrode for the high frequency band and the coil electrode for the low frequency band are formed on a plurality of surfaces of the substrate. 4. The antenna structure according to claim 3, wherein the antenna structure is formed across.

[6] The radiation electrode for the low frequency band is composed of a coil electrode, and the radiation electrode for the high frequency band and the coil electrode for the low frequency band are respectively formed on different surfaces of the substrate. The antenna structure according to claim 3, wherein:

[7] The substrate is configured to be mounted on a printed circuit board, and the radiation electrode for the low frequency band is composed of a coil electrode. The radiation electrode for the high frequency band and the coil electrode for the low frequency band 4. The antenna structure according to claim 3, wherein one or both of them are formed so that a part of the base force is drawn out to the printed circuit board.

[8] An antenna structure in which a substrate having a radiation electrode for a high frequency band that performs antenna operation with a resonance frequency in a high frequency band is mounted on a printed circuit board,

The antenna structure according to claim 1, wherein the base is made of a mixed material including a dielectric material and a magnetic material.

[9] The dielectric material of the mixed material constituting the substrate has a characteristic that the relative permittivity does not substantially change with respect to the change in frequency in the high frequency band to be used, and the magnetic material is in the low frequency band. 9. The antenna structure according to claim 1, wherein the antenna structure has a high relative permeability.

[10] A wireless communication device comprising the antenna structure according to any one of [1] to [8].

[11] A wireless communication device comprising the antenna structure according to [9].

[12] The antenna structure is provided at an edge portion of the circuit board that avoids a mounting area of circuit configuration components in the circuit board built in the wireless communication device.

10. The wireless communication device according to 10. 2. The antenna structure according to claim 1, wherein the antenna structure is provided at an edge portion of the circuit board that avoids a mounting area of circuit configuration components in the circuit board built in the wireless communication device.

11. The wireless communication device according to 11.