JP4688071B2 - ANTENNA DEVICE AND RADIO COMMUNICATION DEVICE - Google Patents

Description

    The present invention relates to an antenna device and a wireless communication device including a frequency adjustment circuit.

Along with miniaturization of mobile phones and the like, antenna devices are also designed to be miniaturized by disposing the radiation electrode on a dielectric substrate to substantially increase the electrical length of the antenna. However, if the antenna device is physically small, the frequency bandwidth may be narrowed. For this reason, there has been proposed an antenna device that is provided with a frequency variable circuit to increase the bandwidth (for example, Patent Document 1 and Patent Document 2).
FIG. 12 is a perspective view showing an example of a conventional antenna device provided with a frequency variable circuit.
As shown in FIG. 12, in this antenna device 200, a loop-shaped radiation electrode 210 that performs a monopole antenna operation is formed on a dielectric substrate 220, and a frequency variable circuit 230 is provided on the loop path of the radiation electrode 210. An intervening configuration is adopted. The frequency variable circuit 230 is configured by soldering parts such as a variable capacitance element 231 such as a barracuda and an inductor 232 onto the radiation electrode 210, and changing the capacitance of the variable capacitance element 231, thereby changing the electric power of the radiation electrode 210. The length can be changed. As a result, the resonant frequency of the antenna device can be changed using the frequency variable circuit 230, and as a result, the frequency bandwidth can be increased.

International Publication No. 2004/109850 JP 2006-060384 A

However, in the conventional antenna device described above, it is difficult to mount small components such as the variable capacitance element 231 and the inductor 232 on the dielectric substrate 220 with high accuracy.
That is, when these components are mounted on the dielectric substrate 220 using a machine, a positioning marker is provided on the surface of the dielectric substrate 220, and the conveyed component is used as a reference for the dielectric substrate 220 with respect to the positioning marker. It was implemented above. However, it is difficult to mount small components such as the variable capacitance element 231 and the inductor 232 at the position of the positioning marker with high accuracy. Moreover, the mounting accuracy decreases as the distance between the small component that has been conveyed and the positioning marker increases.
Further, when the component is surface-mounted on the radiation electrode 210 on the dielectric substrate 220, the surface of the dielectric substrate 220 needs to be flat. A small component requires a higher flatness in the dielectric substrate 220 than a large component. For this reason, when small components such as the variable capacitance element 231 and the inductor 232 are mounted on the dielectric substrate 220 having a normal flatness, some external electrodes of the components float from the radiation electrode 210, resulting in poor contact. There is a risk of entering a state.
Further, in the above-described conventional antenna device, components such as the variable capacitance element 231 and the inductor 232 of the frequency variable circuit 230 are mounted in a state of protruding from the surface of the dielectric substrate 220. There is a risk that parts may come off or be damaged.

  The present invention has been made in order to solve the above-described problems. A frequency adjustment circuit can be mounted without considering the positional accuracy of a component with respect to a substrate, and the degree of freedom in shape design is high and external An object of the present invention is to provide an antenna device and a wireless communication device that are resistant to impact.

In order to solve the above-mentioned problems, the invention of claim 1 is characterized in that a radiation electrode connected to a power supply unit and formed on a substrate, and interposed between the radiation electrode, the first input / output terminal is a radiation. An antenna device comprising: a frequency adjustment circuit connected to the power supply side open end of the electrode and having a second input / output terminal connected to the front end side open end of the radiation electrode, wherein the frequency adjustment circuit is connected to the substrate. And a plurality of components that are mounted on the surface of the substrate to form a circuit, and first and second input / output terminals that are disposed on the surface of the substrate. A plurality of components of the frequency adjustment circuit can be stored and a bottomed recess having a smaller diameter than the substrate of the frequency adjustment circuit is provided, and the substrate of the frequency adjustment circuit is mounted on the recess with the surface facing the recess. And storing a plurality of components in the recess, and Feeding portion side open end and a first output terminal of the radiation electrodes facing each other, and the facing front end portion open end and the second input-output terminals to each other, a configuration in which each connected soldering.
With this configuration, when power of a predetermined frequency is supplied from the power supply unit to the power supply unit side open end of the radiation electrode, the power supply unit side open end and the tip end side open end of the radiation electrode are connected to the first frequency adjustment circuit. Since it is connected to the input / output terminal and the second input / output terminal, electric power is also supplied to the open end of the distal end portion via this frequency adjustment circuit, and is fed to the entire radiation electrode. The radiation electrode resonates at a frequency corresponding to the reactance value of the frequency adjustment circuit.
Since the frequency adjustment circuit is composed of a substrate, a plurality of components mounted on the surface of the substrate and constituting the circuit, and first and second input / output terminals disposed on the surface of the substrate. There is no need to mount multiple small parts directly on the substrate.
Further, since it is sufficient to mount a large substrate on which small components are already mounted on the base, the problem of contact failure of the parts does not occur regardless of the flatness of the surface of the base.
Further, since the shape of the base can be freely deformed and designed, the antenna device itself can be miniaturized and can cope with a narrow antenna mounting area.

According to a second aspect of the present invention, there is provided a radiation electrode connected to the power supply unit and formed on the substrate, and is interposed in the middle of the radiation electrode, the first input / output terminal being open to the power supply unit side of the radiation electrode. An antenna device including a frequency adjustment circuit connected to an end portion and having a second input / output terminal connected to an open end portion on the distal end side of the radiation electrode, the frequency adjustment circuit comprising: a substrate; and a surface of the substrate. The circuit board of the frequency adjustment circuit is composed of a plurality of components that are mounted on the circuit board and the first and second input / output terminals disposed on the surface of the board, and the frequency adjustment circuit of the base is disposed on the substrate. And a second bottomed concave portion capable of accommodating a plurality of components of the frequency adjustment circuit is formed in the concave portion, and a first input / output is provided on the substrate of the frequency adjustment circuit. The first via hole exposed on the back side of the substrate while connected to the terminal Forming a second via hole exposed on the back surface of the substrate in a state of being connected to the second input / output terminal, with the surface on which the plurality of components are mounted facing down, and the plurality of components in the second recess In the housed state, the substrate is housed in the recess, the feeding electrode side open end and the tip end open end of the radiation electrode are projected into the recess, and a spring portion is formed at each of these ends. These spring portions are configured to be in pressure contact with the first via hole and the second via hole, respectively.
With this configuration, it is possible to attach the frequency adjustment circuit to a predetermined location without soldering components constituting the frequency adjustment circuit to the radiation electrode on the dielectric substrate. Therefore, since the substrate does not require heat resistance against soldering, the substrate can be formed from various deformable materials without considering the heat resistance of the substrate.
Further, external impact is directly applied to the back side of the substrate exposed to the outside, and is not directly applied to the component.

According to a third aspect of the present invention, there is provided a radiation electrode connected to the power supply unit and formed on the substrate, and is interposed in the middle of the radiation electrode, and the first input / output terminal of the radiation electrode is at the power supply unit side open end. And a frequency adjustment circuit having a second input / output terminal connected to the open end of the radiation electrode, the frequency adjustment circuit being mounted on the substrate and the surface of the substrate And a plurality of components of the frequency adjustment circuit in a portion where the frequency adjustment circuit of the base is arranged, and a plurality of components constituting the circuit and the first and second input / output terminals disposed on the surface of the substrate. Is provided with a bottomed recess having a smaller diameter than the frequency adjustment circuit board, and the substrate of the frequency adjustment circuit is placed on the recess with the surface facing the recess, and a plurality of components are mounted. housed in the recess, placing a frequency adjustment circuit substrate parts In addition, a plurality of hook portions that can be engaged from above are erected on the edge portion of the substrate, and the edge portion of the substrate is pressed from above with the hook portion to connect the first input / output terminal and the second input / output terminal. The power supply unit side open end and the tip end side open end are electrically connected.
With this configuration, the hook portion erected on the base body engages and presses against the edge of the substrate from above, so that the first and second input / output terminals, the power supply portion side open end, and the tip end side open. The electrical connection with the end becomes stronger.

According to a fourth aspect of the present invention, in the antenna device according to any one of the first to third aspects, the frequency adjustment circuit includes at least one input / output different from the first and second input / output terminals. A terminal is provided, and one or more additional radiation electrodes different from the radiation electrode are formed on the substrate or outside the substrate with the base end positioned in the vicinity of the frequency adjustment circuit, and each additional radiation electrode is formed. The base end portion of the electrode is connected to each of the input / output terminals.
With such a configuration, the antenna portion constituted by the feed electrode side open end, the frequency adjustment circuit, and the tip end side open end of the radiation electrode resonates at a predetermined frequency, and the feed electrode side open end of the radiation electrode and the frequency An antenna portion composed of the adjustment circuit and the additional radiation electrode resonates at another predetermined frequency.

  A fifth aspect of the present invention is the antenna device according to any one of the second to fourth aspects, wherein the base is formed by molding a synthetic resin.

  The invention of claim 6 is the antenna device according to any one of claims 2 to 4, wherein the base is formed by molding a material obtained by adding a dielectric to a synthetic resin.

  The invention according to claim 7 is the antenna device according to any one of claims 1 to 4, wherein the base is formed by molding a dielectric.

The invention according to claim 8 is the antenna device according to any one of claims 2 to 7, wherein the substrate of the frequency adjustment circuit is a flexible substrate.
With this configuration, the frequency adjustment circuit can be provided on the curved surface of the base body by bending the substrate.

According to a ninth aspect of the present invention, in the antenna device according to any one of the first to eighth aspects, the frequency adjustment circuit can change the reactance value of the circuit by controlling the capacitance of the variable capacitance element. The configuration is a frequency variable circuit.
With this configuration, the resonance frequency can be changed by controlling the capacitance of the variable capacitance element even after the frequency variable circuit is attached to the base.

  According to a tenth aspect of the present invention, a wireless communication device includes the antenna device according to any one of the first to ninth aspects.

As described above in detail, according to the antenna device of the present invention, since there is no need to directly mount a plurality of small parts constituting the frequency adjustment circuit on the base, the frequency adjustment can be performed without considering the position accuracy of the parts. There is an excellent effect that the circuit can be mounted with high accuracy. In addition, regardless of the flatness of the surface of the substrate, there is no problem of component contact failure, and production with a high yield is possible.
Further, the degree of freedom in designing the antenna shape is very high, and the antenna can be downsized in accordance with the antenna mounting area.
Furthermore, since external impacts are not directly applied to the parts, durability against external impacts is high.

In particular, according to the second aspect of the present invention, since the base can be formed of various deformable materials without considering the heat resistance of the base, the base can be formed into a narrow antenna mounting space having a special shape. By making it correspond, it can also mount in this antenna mounting space, As a result, the further miniaturization of an antenna apparatus can be achieved.
Furthermore, since an external impact is not directly applied to the component, an antenna device that is resistant to the external impact can be realized.

  According to the invention of claim 3, the hook portion erected on the base body electrically connects the first and second input / output terminals, the power supply portion side open end portion, and the tip end portion side open end portion. Since it is made stronger, the antenna characteristics can be further enhanced.

  Furthermore, according to the invention of claim 4, it is possible to realize an antenna device that is small in size and capable of multi-resonance.

  Further, according to the inventions of claims 5 and 6, since the substrate is formed of synthetic resin or a material obtained by adding a dielectric to synthetic resin, the shape of the substrate can be freely deformed.

  According to the invention of claim 8, since the frequency adjusting circuit can be provided on the curved surface, the degree of freedom in designing the substrate can be further increased.

  According to the ninth aspect of the present invention, the resonance frequency can be changed by controlling the capacitance of the variable capacitance element even after the frequency variable circuit is attached to the substrate. Can be done.

  According to the tenth aspect of the present invention, it is possible to realize a wireless communication device that is small, resistant to external impact, and capable of high-quality communication.

It is a disassembled perspective view which isolate | separates and shows a frequency adjustment circuit about the antenna apparatus which concerns on 1st Example of this invention. It is an equivalent circuit diagram of a frequency adjustment circuit. It is sectional drawing which shows the state which isolate | separated the frequency adjustment circuit from the base | substrate. It is sectional drawing which shows the attachment state to the base | substrate of a frequency adjustment circuit. It is a top view which shows the attachment state to the base | substrate of a frequency adjustment circuit. It is a diagram for demonstrating adjustment of the resonant frequency. It is sectional drawing which shows the attachment state to the base | substrate of the frequency adjustment circuit in 2nd Example of this invention. It is a top view which shows the attachment state to the base | substrate of a frequency adjustment circuit. It is sectional drawing which shows the attachment state to the base | substrate of the frequency adjustment circuit in 3rd Example of this invention. It is a top view which shows the attachment state to the base | substrate of a frequency adjustment circuit. It is an equivalent circuit schematic of the frequency variable circuit which is the principal part of the antenna apparatus which concerns on 4th Example of this invention. It is a perspective view which shows an example of the conventional antenna device.

  The best mode of the present invention will be described below with reference to the drawings.

Example 1
FIG. 1 is an exploded perspective view showing a frequency adjustment circuit 4 separated from the antenna device according to the first embodiment of the present invention.
The antenna device 1 of this embodiment is provided in a wireless communication device such as a mobile phone.
As shown in FIG. 1, the antenna device 1 is formed in a non-ground region 101 of a circuit board 100 of a wireless communication device, and exchanges high-frequency signals with a power feeding unit 110 such as a transmission / reception unit.
The antenna device 1 includes a base 2, a radiation electrode 3, and a frequency adjustment circuit 4 interposed in the middle of the radiation electrode 3.

  The base 2 is made of ceramic and has a rectangular parallelepiped shape.

The radiation electrode 3 is a conductor having a loop shape as a whole, and is formed on the base 2.
Specifically, the radiation electrode 3 is separated into a power feeding unit side electrode 31 and a tip end side electrode 32 with a bottomed recess 5 as a mounting unit of a frequency adjusting circuit 4 described later. The power feeding unit side electrode 31 is connected to the power feeding unit 110 through a conductor pattern 111 formed on the non-ground region 101. The power feeding portion side electrode 31 climbs the left side portion of the front surface 21 of the base 2, goes straight on the upper surface 22 for a predetermined distance, then bends to the right side, and reaches the left edge of the concave portion 5 for the frequency adjustment circuit 4. On the other hand, the tip portion side electrode 32 proceeds from the right edge of the recess 5 to the right on the upper surface 22, and proceeds to the back surface 23 side along the right edge portion of the upper surface 22. After that, after bending to the left at the right corner of the upper surface 22, it proceeds to the left on the upper surface 22, bends to the front 21 side at the left corner of the upper surface 22, and its tip faces the power supply unit side electrode 31.

  The frequency adjustment circuit 4 is a circuit capable of adjusting the resonance frequency of the antenna device 1 including the radiation electrode 3 and the frequency adjustment circuit 4 by changing the reactance value of the entire radiation electrode 3 according to the reactance value.

FIG. 2 is an equivalent circuit diagram of the frequency adjustment circuit 4.
As the frequency adjustment circuit 4, various circuits can be applied. For example, a single inductor, a single capacitor, a series resonance circuit or parallel resonance circuit of an inductor and a capacitor, or a circuit in which an inductor or a capacitor is connected in series to these resonance circuits can be applied.
In this embodiment, as shown in FIG. 2, a capacitor 43 is connected in parallel to a series circuit of a capacitor 41 and an inductor 42 to constitute a frequency adjustment circuit 4, and a terminal 4a is connected to the first input of this parallel circuit. An output terminal was used, and the terminal 4b was a second input / output terminal.
Specifically, as shown in FIG. 1, a conductor pattern 4c is formed on the surface of a ceramic substrate 40, and a capacitor 41, an inductor 42 and a capacitor 43 are mounted on the conductor pattern 4c. Then, terminals 4a and 4b were formed at both ends of the conductor pattern 4c.
The frequency adjusting circuit 4 is formed separately from the base 2 and the radiation electrode 3 and attached to the base 2 by soldering.

3 is a cross-sectional view showing a state in which the frequency adjustment circuit 4 is separated from the base body 2, FIG. 4 is a cross-sectional view showing a state in which the frequency adjustment circuit 4 is attached to the base body 2, and FIG. It is a top view which shows the attachment state to the base | substrate 2 of the circuit 4. FIG.
That is, as shown in FIG. 3, the recess 5 is provided on the upper surface 22 of the base 2, and the diameter of the recess 5 is set smaller than the outer diameter of the substrate 40. Further, the diameter of the recess 5 is set to a size that can accommodate components such as the capacitor 41 , and the depth to the bottom 5a is set deeper than the height of these components.
Then, with the solders 45 and 46 attached to the terminals 4a and 4b of the frequency adjustment circuit 4, the surface of the substrate 40 is directed downward, and the terminals 4a and 4b are placed on the power feeding part side electrode 31 and the tip part of the radiation electrode 3. The entire substrate 40 was lowered toward the recess 5 while being positioned directly above the side electrode 32. As a result, the terminals 4a and 4b come into contact with the open end portions 31a and 32a.
In this state, by performing reflow soldering, as shown in FIG. 4, the terminal 4 a of the conductor pattern 4 c is connected to the open end of the power feeding unit side electrode 31 in a state where components such as the capacitor 41 are accommodated in the recess 5. While soldering to 31a, the terminal 4b was soldered to the open end part 32a of the front end side electrode 32.
In this way, as shown in FIG. 5, the substrate 40 covers and protects the components such as the capacitor 41 housed in the recess 5 from above the recess 5.

Next, operations and effects of the antenna device of this embodiment will be described.
FIG. 6 is a diagram for explaining adjustment of the resonance frequency.
In FIG. 1 and FIG. 4, when power of a predetermined frequency is supplied from the power supply unit 110 to the power supply unit side electrode 31 of the radiation electrode 3, the open end 31 a of the power supply unit side electrode 31 is connected to the terminal 4 a of the frequency adjustment circuit 4 through the solder 45. The power enters the frequency adjustment circuit 4. Since the open end 32 a of the tip end side electrode 32 is connected to the terminal 4 b through the solder 46, power is supplied from the frequency adjustment circuit 4 to the tip end side electrode 32. As a result, power is supplied to the entire radiation electrode 3 through the frequency adjustment circuit 4, and the portion including the radiation electrode 3 and the frequency adjustment circuit 4 resonates at a frequency corresponding to the reactance value of the frequency adjustment circuit 4.
Therefore, when the resonance frequency of the radiation electrode 3 not including the frequency adjustment circuit 4 is the frequency f1 as shown by the solid return curve S in FIG. 6, the resonance frequency is lower than the frequency f1. When it is desired to set the frequency f 1 ′, a frequency adjustment circuit 4 having a large reactance value is interposed in the radiation electrode 3. As a result, the electrical length of the entire radiation electrode 3 is increased, and the resonance frequency is lowered to the frequency f1 ′ as indicated by the broken return curve S in FIG.
As described above, according to this embodiment, the frequency can be changed only by changing the components such as the capacitors 41 and 43 and the inductor 42 of the frequency adjustment circuit 4. Can be achieved.

Further, since the frequency adjustment circuit 4 is formed separately from the base 2 and the radiation electrode 3, it is not necessary to mount small parts such as the capacitor 41 constituting the frequency adjustment circuit 4 directly on the radiation electrode 3 of the base 2. . Therefore, by using the antenna device 1 of this embodiment, the frequency adjustment circuit 4 can be mounted on the radiation electrode 3 with high accuracy without considering the positional accuracy of components such as the capacitor 41. Further, since the substrate 40 of the frequency adjusting circuit 4 only needs to be mounted on the base 2, there is no problem of component contact failure even when the flatness of the surface such as the upper surface 22 of the base 2 is low. As a result, it is possible to produce the antenna device 1 with a high yield.
Further, as shown in FIG. 5, since the substrate 40 is configured to cover and protect the components such as the capacitor 41 housed in the recess 5 from above the recess 5, even when an external impact is applied, The external impact is directly applied to the back side of the substrate 40 exposed to the outside, and is not directly applied to components such as the capacitor 41 accommodated in the recess 5.

(Example 2)
Next explained is the second embodiment of the invention.
FIG. 7 is a cross-sectional view showing a state in which the frequency adjustment circuit 4-3 is attached to the base 2 in the second embodiment of the present invention, and FIG. 8 shows a state in which the frequency adjustment circuit 4-3 is attached to the base 2. FIG.
As shown in FIG. 7 and FIG. 8, the antenna device of this embodiment has a frequency adjustment circuit housed in a recess, and feeds side electrode 31 and tip side electrode 32 of radiation electrode 3 and terminals of the frequency adjustment circuit. 4a and 4b are different from the first embodiment in that the connection is made without using solder.
That is, in the first embodiment, since the power supply unit side electrode 31, the tip end unit side electrode 32 and the terminals 4a and 4b are connected by the solders 45 and 46, ceramics having high heat resistance are used as the base 2. . However, in ceramics, since the degree of freedom in designing the shape of the substrate 2 is limited, it is preferable to form the substrate 2 using a resin having a high degree of freedom in shape design or a material obtained by adding a dielectric to the resin. However, in this case, in order to ensure the degree of freedom of shape, it is necessary to use a heat-resistant resin that can be soldered. There is no such restriction in the case of a pressure contact structure that is not soldered.
Details will be described below.
This antenna device also includes a base 2, a radiation electrode 3, and a frequency adjustment circuit 4-3 interposed in the middle of the radiation electrode 3.
The substrate 2 is formed by molding a synthetic resin or a material obtained by adding a dielectric to a synthetic resin. Such a material increases the degree of freedom in designing the shape of the base 2 as described above, but in this example, it was formed in a rectangular parallelepiped shape.

  The shape and the like of the radiation electrode 3 are substantially the same as in the first embodiment. However, the open end portion 31a of the power supply unit side electrode 31 that is the open end portion of the power supply unit and the open end portion 32a of the tip end side electrode 32 that is the open end portion of the front end portion protrude into the recess 5 and are downward. Curved spring portions 31b and 32b are formed on the open end portion 31a and the open end portion 32a, respectively.

The frequency adjustment circuit 4-3 is the same in electrical circuit as the frequency adjustment circuit 4 of the first embodiment, but is different in size.
That is, the outer diameter of the substrate 40 of the frequency adjustment circuit 4-3 is set to be substantially the same as the diameter of the recess 5. A via hole 4e as a first via hole and a via hole 4f as a second via hole are provided in the substrate 40 of the frequency adjustment circuit 4-3. Specifically, the via holes 4e and 4f are exposed on the back surface of the substrate 40 in a state where the via holes 4e and 4f are connected to the terminals 4a and 4b.

  The shape and the like of the recess 5 are substantially the same as those in the first embodiment. However, in this recess 5, a recess 51 is formed as a second recess that can accommodate the capacitors 41 and 43 and the inductor 42 of the frequency adjustment circuit 4-3.

The frequency adjusting circuit 4-3 described above is housed in the concave portion 5 with its surface facing down and the via holes 4e and 4f facing the spring portions 31b and 32b of the radiation electrode 3, and is mounted on the substrate 40. The mounted capacitors 41 and 43 and the inductor 42 are accommodated in the recess 51.
In this state, the spring portions 31 b and 32 b of the power feeding portion side electrode 31 and the tip end portion side electrode 32 are pressed against the via holes 4 e and 4 f exposed on the back surface of the substrate 40.

Next, operations and effects of the antenna device of this embodiment will be described.
In FIG. 7, when electric power of a predetermined frequency is supplied from the power feeding unit 110 (see FIG. 1) to the power feeding unit side electrode 31 of the radiation electrode 3, the spring part 31b of the power feeding unit side electrode 31 is connected to the via hole 4e of the frequency adjusting circuit 4-3. The power enters the frequency adjustment circuit 4-3 through the terminal 4a. Since the spring portion 32b of the tip end side electrode 32 is in pressure contact with the via hole 4f, power is supplied to the tip end side electrode 32 through the terminal 4b and the via hole 4f of the frequency adjustment circuit 4-3. As a result, power is supplied to the entire radiation electrode 3 through the frequency adjustment circuit 4-3, and the portion including the radiation electrode 3 and the frequency adjustment circuit 4-3 corresponds to the reactance value of the frequency adjustment circuit 4-3. Resonates at the specified frequency.

Further, in the antenna device of this embodiment, the frequency adjustment circuit 4-3 created separately from the base 2 and the radiation electrode 3 is housed in the recess 5, and the feeding portion side electrode 31 and the tip portion side electrode of the radiation electrode 3 are accommodated. The structure which aims at the electrical connection with the electric power feeding part side electrode 31, the front-end | tip part side electrode 32, and the terminals 4a and 4b by the mechanical contact of the spring parts 31b and 32b of 32, and the via holes 4e and 4f of the frequency adjustment circuit 4-3. Therefore, soldering or the like is not required when the frequency adjustment circuit 4-3 is mounted on the base 2. For this reason, since the base 2 does not require heat resistance, the base 2 can be formed of various deformable materials.
Therefore, as described above, the base 2 is formed of a synthetic resin or a material obtained by adding a dielectric to a synthetic resin. Therefore, in this embodiment, the shape of the base 2 is formed in a rectangular parallelepiped shape, but the shape of the base 2 is not limited to this, and can be formed in various shapes. By freely deforming the shape of the base 2, it can be mounted in a narrow antenna mounting space having a special shape, and the antenna device can be miniaturized.

By the way, in the antenna device of this embodiment, the spring portions 31b and 32b of the power feeding portion side electrode 31 and the tip end portion side electrode 32 are in pressure contact with the via holes 4e and 4f of the substrate 40 of the frequency adjustment circuit 4-3. Are electrically connected to the frequency adjustment circuit 4-3. Therefore, contact resistance is reduced as compared with the case where electrical connection is achieved by merely bringing the open end portions 31a and 32a into contact with the via holes 4e and 4f without providing the spring portions 31b and 32b. Further, the thickness of the substrate 40 is usually not flat on the entire surface, but varies. Even in such a case, the spring portions 31b and 32b absorb variations due to their elasticity, so that contact failure due to variations in thickness does not occur.
Since other configurations, operations, and effects are the same as those in the first embodiment, description thereof is omitted.

(Example 3)
Next explained is the third embodiment of the invention.
FIG. 9 is a cross-sectional view showing a state in which the frequency adjustment circuit 4 is attached to the base 2 in the third embodiment of the present invention, and FIG. 10 is a plan view showing a state in which the frequency adjustment circuit 4 is attached to the base 2. is there.
The antenna device of this embodiment is different from the first and second embodiments in the fixing structure of the frequency adjustment circuit 4.

That is, as shown in FIGS. 9 and 10, the four hook portions 61 and 62 facing the concave portion 5 side are erected on the edge portion of the concave portion 5 so as to face each other. On the other hand, the power supply portion side electrode 31 of the radiation electrode 3 and the open end portions 31 a and 32 a of the tip end portion side electrode 32 were not projected into the recess 5, but were positioned at the opening edge of the recess 5.
Then, the substrate 40 of the frequency adjustment circuit 4 is placed on the peripheral portion of the recess 5 with the back surface thereof facing up, and the back surface edge portion of the substrate 40 is engaged with the four hook portions 61 and 62. The terminals 4a and 4b were brought into contact with the open end portions 31a and 32a of the power feeding portion side electrode 31 and the tip end portion side electrode 32, respectively.

With this configuration, the four hook portions 61 and 62 are engaged with and pressed against the edge of the substrate 40 from above, so that the open ends of the terminals 4a and 4b, the power feeding portion side electrode 31, and the tip portion side electrode 32 are provided. The electrical connection with 31a and 32a becomes stronger.
Other configurations, operations, and effects are the same as those in the first and second embodiments, and thus description thereof is omitted.

Example 4
FIG. 11 is an equivalent circuit diagram of a frequency variable circuit which is a main part of the antenna device according to the fourth embodiment of the present invention.
The antenna device of this embodiment is different from the first to third embodiments in that a frequency variable circuit is used as a frequency adjustment circuit.

That is, as shown in FIG. 11, a frequency variable circuit 4 ′ that can change the reactance value of the circuit by controlling the variable capacitance element is used as the frequency adjustment circuit.
In the frequency variable circuit 4 ′, a varactor 44 as a variable capacitance element is used instead of the capacitor 43 constituting the frequency adjustment circuit 4 (4-3) shown in FIG. The barracuda 44 is a diode that changes its capacitance according to the voltage value of the DC control voltage Vc.

With this configuration, when the DC control voltage Vc is input from the DC power source (not shown) to the cathode side of the varactor 44, the capacity of the varactor 44 changes according to the voltage value of the DC control voltage Vc, and the frequency variable circuit 4 ' The reactance value changes, and the resonance frequency of the antenna device changes. Therefore, even after the frequency variable circuit 4 ′ is attached to the base 2, the resonance frequency can be freely changed, so that the resonance frequency can be adjusted with high accuracy.
Since other configurations, operations, and effects are the same as those in the first to third embodiments, description thereof is omitted.

  DESCRIPTION OF SYMBOLS 1 ... Antenna apparatus, 2 ... Base | substrate, 3 ... Radiation electrode, 4,4-3 ... Frequency adjustment circuit, 4 '... Frequency variable circuit, 4a, 4b ... Terminal, 4c ... Conductor pattern, 4e, 4f ... Via hole, 5, 51: Recess, 5a ... Bottom, 21 ... Front, 22 ... Top, 23 ... Back, 31 ... Feeder side electrode, 31a, 32a ... Open end, 31b, 32b ... Spring part, 32 ... Tip side electrode, 40 ... Board, 41, 43 ... Capacitor, 42 ... Inductor, 44 ... Barracuda, 45, 46 ... Solder, 61, 62 ... Hook part, 100 ... Circuit board, 101 ... Non-ground area, 110 ... Feeding part, 111 ... Conductor pattern .

Claims (10)

A radiation electrode connected to the power supply unit and formed on the substrate, and a first input / output terminal of the radiation electrode connected to the power supply unit side open end of the radiation electrode An antenna device comprising an input / output terminal and a frequency adjusting circuit connected to the open end of the radiation electrode,
The frequency adjusting circuit includes a substrate, a plurality of components that are mounted on the surface of the substrate to form a circuit, and the first and second input / output terminals disposed on the surface of the substrate,
In the part where the frequency adjustment circuit of the base is arranged, a plurality of components of the frequency adjustment circuit can be accommodated and a recessed portion having a bottom with a smaller diameter than the substrate of the frequency adjustment circuit is provided.
The substrate of the frequency adjustment circuit is placed on the recess with the surface facing the recess, and a plurality of components are housed in the recess, and the radiation electrode side open end of the radiation electrode faces each other. And the first input / output terminal, and the distal end side open end and the second input / output terminal facing each other, were soldered and connected, respectively.
An antenna device characterized by that. A radiation electrode connected to the power supply unit and formed on the substrate, and a first input / output terminal of the radiation electrode connected to the power supply unit side open end of the radiation electrode An antenna device comprising an input / output terminal and a frequency adjusting circuit connected to the open end of the radiation electrode,
The frequency adjusting circuit includes a substrate, a plurality of components that are mounted on the surface of the substrate to form a circuit, and the first and second input / output terminals disposed on the surface of the substrate,
A bottomed recess capable of accommodating the frequency adjustment circuit board is provided in a portion of the base body where the frequency adjustment circuit is disposed, and a bottomed first recess capable of accommodating a plurality of components of the frequency adjustment circuit in the recess. 2 recesses,
A first via hole exposed on the back surface of the substrate in a state connected to the first input / output terminal on the substrate of the frequency adjustment circuit, and an exposed back surface of the substrate in a state connected to the second input / output terminal. Forming a second via hole,
With the surface on which the plurality of components are mounted facing down, the substrate is stored in the recess in a state where the plurality of components are stored in the second recess,
The radiation electrode side open end and the tip end side open end of the radiation electrode protrude into the recess, and spring portions are formed at these ends, respectively, and these spring portions are connected to the first via hole and the first via hole. The two via holes were in pressure contact with each other .
An antenna device characterized by that. A radiation electrode connected to the power supply unit and formed on the substrate, and a first input / output terminal of the radiation electrode connected to the power supply unit side open end of the radiation electrode An antenna device comprising an input / output terminal and a frequency adjusting circuit connected to the open end of the radiation electrode,
The frequency adjusting circuit includes a substrate, a plurality of components that are mounted on the surface of the substrate to form a circuit, and the first and second input / output terminals disposed on the surface of the substrate,
In the part where the frequency adjustment circuit of the base is arranged, a plurality of components of the frequency adjustment circuit can be accommodated and a recessed portion having a bottom with a smaller diameter than the substrate of the frequency adjustment circuit is provided.
The substrate of the frequency adjustment circuit is placed on the recess with the surface facing the recess, and a plurality of components are housed in the recess.
A plurality of hook portions that can be engaged with the edge portion of the substrate from above are erected at a portion where the frequency adjustment circuit of the base is disposed, and the edge portion of the substrate is pressed from above with the hook portion, The first input / output terminal and the second input / output terminal were electrically connected to the power feeding unit side open end and the tip end side open end,
An antenna device characterized by that. The frequency adjusting circuit is provided with one or more input / output terminals different from the first and second input / output terminals,
One or more additional radiation electrodes different from the radiation electrode are formed on the substrate or outside the substrate in a state where the base end portion is positioned in the vicinity of the frequency adjustment circuit,
The base end of each additional radiation electrode was connected to each input / output terminal.
The antenna device according to any one of claims 1 to 3, wherein the antenna device is provided. The base is formed by molding a synthetic resin.
The antenna device according to any one of claims 2 to 4, wherein the antenna device is provided. The base is formed by molding a material obtained by adding a dielectric to a synthetic resin.
The antenna device according to any one of claims 2 to 4, wherein the antenna device is provided. The base is formed by molding a dielectric.
The antenna device according to any one of claims 1 to 4, wherein the antenna device is provided. The substrate of the frequency adjustment circuit is a flexible substrate.
The antenna device according to claim 2, wherein the antenna device is an antenna device. The frequency adjustment circuit is a frequency variable circuit that can change the reactance value of the circuit by controlling the capacitance of the variable capacitance element.
9. The antenna device according to claim 1, wherein the antenna device is characterized in that: Comprising the antenna device according to any one of claims 1 to 9,
A wireless communication device.

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