JP6825750B2 - Antenna device and electronic equipment - Google Patents

Description

The present invention relates to an antenna device and an electronic device including the antenna device.

In a portable electronic device provided with an antenna device, the antenna device is provided together with an electronic circuit in a portable, limited-sized housing. Therefore, there are naturally restrictions on the size of the circuit board and the size of the antenna device that can be accommodated in the housing.

On the other hand, the frequency band used for communication is becoming wider, but as mentioned above, there is not enough space to install antennas, and it is difficult to install a large number of antennas to cover a plurality of frequency bands. ing.

As one method of widening the frequency characteristics of the radiation gain of the antenna device, the characteristics of the non-feeding radiation element are fed and radiated by magnetically coupling the non-feeding radiation element physically separated from the power supply circuit to the power supply radiation element. Conventionally, a method of adding to the characteristics of the device has been used.

For example, Patent Document 1 discloses an antenna device including two radiating elements and a coupling degree adjusting circuit for controlling power supply to the two radiating elements.

International Publication No. 2012/153690

However, in order to construct an antenna device applicable to further wideband communication in recent years, the above-mentioned method of adding a non-feeding radiation element cannot be applied. For example, even if another non-feeding radiation element is placed close to the non-feeding radiation element coupled to the feeding radiation element, the effect of widening the bandwidth is small. This is because the newly added passive repeater cannot receive sufficient power from the already provided passive repeater.

An object of the present invention is to provide an antenna device including a fed radiation element and a non-feed radiation element, which effectively widens the bandwidth, and an electronic device including the antenna device.

The antenna device as an example of the present disclosure is
A first coupling element including a first coil and a second coil coupled to the first coil, a feeding circuit, a feeding radiation element, a first non-feeding radiation element, and a second non-feeding radiation element are provided.
The feeding radiation element is connected to the power feeding circuit, the first coil is connected between the first non-feeding radiation element and the ground, and the second coil is the second non-feeding radiation element and the ground. Connected in between
The first non-feeding radiating element is fed by electric field coupling with the feeding radiating element, and the second non-feeding radiating element is fed via the first coupling element.

According to the above configuration, the feeding radiation element and the first non-feeding radiation element can be strongly electrocoupled, and the second non-feeding radiation element is coupled to the first non-feeding radiation element via the coupling element. , The characteristics of the second non-feeding radiation element as a radiation element are effectively utilized. Therefore, a wide band antenna device can be obtained.

An electronic device as an example of the present disclosure includes the antenna device, a circuit board on which a power feeding circuit connected to the antenna device is formed, and a housing for accommodating the antenna device and the circuit board.

With the above configuration, an electronic device including an antenna device provided in a limited space in the housing can be obtained.

According to the present invention, a wideband antenna device including a feeding radiation element and a non-feeding radiation element, and an electronic device including the wideband antenna device can be obtained.

FIG. 1A is a circuit diagram of the antenna device 101A according to the first embodiment. Further, FIG. 1B is a circuit diagram of the antenna device 101B according to the first embodiment. FIG. 2A is a plan view of a main part of the electronic device 201 including the antenna device 101A, and FIG. 2B is a side view thereof. FIG. 2C is a schematic circuit diagram of the antenna device 101A formed on the circuit board 40. FIG. 3 is a perspective view of an electronic device including the antenna device 101A. FIG. 4 is a cross-sectional view of the electronic device 201 including the antenna device 101A. FIG. 5 is a perspective view of the coupling element 30. FIG. 6 is an exploded plan view showing a conductor pattern formed in each layer of the coupling element 30. FIG. 7 is a circuit diagram of the coupling element 30 including four coil conductor patterns. FIG. 8 is a diagram showing the frequency characteristics of the reflection coefficient of the antenna device 101A. FIG. 9 is a circuit diagram of the antenna device 102 according to the second embodiment. 10 (A) is a plan view of a main part of an electronic device 202 including an antenna device 102, and FIG. 10 (B) is a side view thereof. FIG. 11 is a circuit diagram of the antenna device 103 according to the third embodiment. FIG. 12 is a circuit diagram of the antenna device 104 according to the fourth embodiment. FIG. 13 is a diagram showing the frequency characteristics of the reflection coefficient of the antenna device 104. FIG. 14 is a circuit diagram of an antenna device as a comparative example.

First, the configurations of various aspects of the antenna device and the electronic device according to the present invention will be described.

The antenna device of the first aspect according to the present invention is
A coupling element including a first coil and a second coil that couples to the first coil,
The first and second non-feeding radiating elements that are indirectly fed from the feeding circuit and the feeding radiating element that is directly fed from the feeding circuit are provided.
The first coil is connected between the first passive repeater and the ground.
The second coil is connected between the second passive repeater and the ground.
The first non-feeding radiating element is electrically coupled to the feeding radiating element.

According to the above configuration, the feeding radiation element and the first non-feeding radiation element can be strongly electrocoupled, and the second non-feeding radiation element is coupled to the first non-feeding radiation element via the coupling element. , The characteristics of the second non-feeding radiation element as a radiation element are effectively utilized. Therefore, a wide band antenna device can be obtained.

In the antenna device of the second aspect according to the present invention, the first coupling element is an element in which a plurality of insulating base materials and a plurality of conductor patterns are laminated, and the plurality of conductor patterns are the plurality of insulating materials. The first coil and the second coil are formed on the surface of the base material, and are formed by one or more conductor patterns among the plurality of conductor patterns. According to this structure, a small first coupling element having a high coupling coefficient is configured, and a small antenna device can be obtained.

The antenna device of the third aspect according to the present invention has a portion in which the feeding radiation element and the first non-feeding radiation element extend in the same direction with each other. According to this structure, the coupling between the feeding radiation element and the first non-feeding radiation element can be enhanced.

In the antenna device of the fourth aspect according to the present invention, the fed radiation element resonates in the first frequency band and the second frequency band having a frequency higher than the first frequency band, and the first non-feeding radiation The element and the second non-feeding radiation element resonate in the second frequency band. According to this structure, the second frequency band can be widened.

In the antenna device of the fifth aspect according to the present invention, the resonance frequency of the second non-feeding radiation element is the resonance frequency of the feeding radiation element in the second frequency band and the resonance frequency of the first non-feeding radiation element. between. According to this structure, the second frequency band having a high frequency band can be effectively widened.

In the antenna device of the sixth aspect according to the present invention, the feeding radiation element, the first non-feeding radiation element and the second non-feeding radiation element are formed so as to be arranged in a plane direction, and the first non-feeding radiation element is formed. Is in a position sandwiched between the feeding radiation element and the second non-feeding radiation element. According to this structure, the radiation efficiency of the second non-feeding radiation element is higher than that of the first non-feeding radiation element, so that the resonance frequency in the second frequency band of the feeding radiation element and the resonance frequency of the first non-feeding radiation element The gain between them is increased, and the second frequency band is effectively widened.

In the antenna device of the seventh aspect according to the present invention, the ground is a ground conductor, and the feeding radiation element is arranged at a position farther from the ground conductor than the first non-feeding radiation element. According to this structure, the radiation efficiency of the long wire feeding radiation element connected to the feeding circuit is increased.

The antenna device of the eighth aspect according to the present invention is an inverted F type radiating element in which the feeding radiating element has a feeding line and a short-circuit line. According to this structure, an antenna device having a small-sized feeding radiation element having high radiation efficiency can be obtained.

The antenna device of the ninth aspect according to the present invention includes an inductor connected in series between the short-circuit line of the inverted F type radiating element and the ground. According to this structure, it is possible to obtain an antenna device having a feeding radiation element corresponding to low-band communication while being compact.

The antenna device of the tenth aspect according to the present invention has a portion extending in a direction away from the first non-feeding radiation element from the connection portion of the feeding line to the inverted F type radiation element. According to this structure, the influence of the first passive radiating element on the feeding radiating element is small, and the magnetic field coupling between the first passive radiating element and the feeding radiating element can be enhanced.

In the antenna device of the eleventh aspect according to the present invention, the feeding radiation element is connected between the feeding circuit and the ground, and the first non-feeding radiation element and the second non-feeding radiation element are the feeding radiation elements. Partially surrounded by. According to this structure, the first non-feeding radiation element and the second non-feeding radiation element can be arranged in a limited space together with the feeding radiation element, and a small antenna device is configured.

The antenna device of the twelfth aspect according to the present invention includes an impedance adjusting circuit connected between the fed radiation element and the ground, and has a resonance frequency of the first non-feeding radiation element and the second non-feeding radiation element. The impedance of the impedance adjusting circuit at the resonance frequency of is higher than the impedance at the resonance frequency of the feeding radiation element. According to this structure, at the resonance frequency of the first non-feeding radiation element and the resonance frequency of the second non-feeding radiation element, the feeding radiation element is substantially relative to the first non-feeding radiation element and the second non-feeding radiation element. Since there is no effect, the radiation efficiency of the first non-feeding radiation element or the second non-feeding radiation element alone can be maintained.

The antenna device of the thirteenth aspect according to the present invention includes a capacitor connected in series between the first passive repeater and the first coil. According to this structure, the resonance frequency of the first passive repeater can be set to a predetermined frequency without shortening the line length of the first passive repeater. Therefore, the degree of coupling between the first non-feeding radiation element and the feeding radiation element can be ensured.

The antenna device of the fourteenth aspect according to the present invention has a second coupling element including a third coil and a fourth coil coupled to the third coil, and the feeding circuit via the first coupling element and the second coupling element. The third coil is connected between the second non-feeding radiation element and the ground, and the fourth coil is the third non-feeding radiation element and the ground. Is connected to. According to this structure, a wider band can be further achieved by the three non-feeding radiation elements.

The electronic device according to the fifteenth aspect according to the present invention includes the antenna device according to any one of the antenna devices according to the first aspect to the antenna device according to the twelfth aspect, and the feeding circuit connected to the antenna device. A circuit board on which the antenna device is formed and a housing for accommodating the antenna device and the circuit board are provided. According to this structure, an electronic device including a wideband antenna device can be obtained.

In the electronic device according to the sixteenth aspect of the present invention, the power feeding radiation element, the first non-feeding radiation element, and the second non-feeding radiation element are formed of a dielectric or an insulator covering a part of the circuit board. It is a conductor pattern. According to this structure, an electronic device provided with a space-saving and high-gain antenna device can be obtained as compared with a structure in which each radiating element is formed on a circuit board.

In the electronic device of the seventeenth aspect according to the present invention, the power feeding radiating element has a shape along the outer edge of the housing. According to this structure, an electronic device provided with a relatively large-sized feeding radiation element is configured without limiting the space inside the housing.

Hereinafter, a plurality of embodiments for carrying out the present invention will be shown with reference to the drawings with reference to some specific examples. The same reference numerals are given to the same parts in each figure. Although the embodiments are shown separately for convenience of explanation in consideration of the explanation of the main points or the ease of understanding, partial replacement or combination of the configurations shown in different embodiments is possible. In the second and subsequent embodiments, the description of matters common to those of the first embodiment will be omitted, and only the differences will be described. In particular, similar actions and effects with the same configuration will not be mentioned sequentially for each embodiment.

<< First Embodiment >>
FIG. 1A is a circuit diagram of the antenna device 101A according to the first embodiment. Further, FIG. 1B is a circuit diagram of another antenna device 101B according to the first embodiment.

The antenna device 101A includes a feeding radiation element 10, a first non-feeding radiation element 21, a second non-feeding radiation element 22, and a coupling element 30.

The coupling element 30 includes a first coil L1 and a second coil L2 that is electromagnetically coupled (mainly magnetically coupled) to the first coil L1. Considering that the coupling between the first coil L1 and the second coil L2 is enhanced, the coupling element 30 is preferably a laminated transformer or chip component in which the first coil L1 and the second coil L2 are laminated.

The first coil L1 of the coupling element 30 is connected between the first passive repeater 21 and the ground, and the second coil L2 is connected between the second passive repeater 22 and the ground.

The first non-feeding radiation element 21 and the feeding radiation element 10 have a portion extending in the same direction, and the first non-feeding radiation element 21 is electrically coupled to the feeding radiation element 10 at the extending portion. The arrow lines at both ends in FIGS. 1 (A) and 1 (B) illustrate this electric field coupling. The portion where the first non-feeding radiation element 21 and the feeding radiation element 10 extend in the same direction is a portion where the first non-feeding radiation element 21 and the feeding radiation element 10 run in parallel with each other at intervals.

The feed radiation element 10 is an inverted F type radiation element including a main radiation element 11, a sub radiation element 12, a feed line 13, and a short circuit line 14. A feeding circuit 1 is connected between the feeding line 13 and the ground. Inductors Ls are connected in series between the short-circuit line 14 and the ground.

In the method of taking the XY coordinate axes shown in FIGS. 1 (A) and 1 (B), the main radiating element 11 extends in the Y direction from the ends of the first stretched portion 11A and the first stretched portion 11A in the X direction. A second stretched portion 11B to be stretched, a third stretched portion 11C extending in the −Y direction from the end of the second stretched portion 11B, and a fourth stretched portion 11D extending in the −X direction from the end of the third stretched portion 11C. Consists of.

The sub-radiating element 12 extends in the X direction from the middle of the first extending portion 11A of the main radiating element 11 and is arranged between the second extending portion 11B and the fourth extending portion 11D of the main radiating element 11. Then, a stray capacitance Cs is formed between the vicinity of the tip of the sub-radiating element 12 and the vicinity of the tip of the main radiating element 11 (near the tip of the fourth extending portion 11D). The stray capacitance Cs is a capacitance generated between the conductor pattern constituting the main radiation element 11 and the conductor pattern constituting the sub-radiation element 12. This stray capacitance is a capacitance component added to the radiation element of the inverted F antenna, and the resonance frequencies of the main radiation element 11 and the sub-radiation element 12 are adjusted by the magnitude of the stray capacitance.

The antenna device 101A includes a capacitor C connected in series between the first passive repeater 21 and the first coil L1 of the coupling element 30. This capacitor C is provided to raise the resonance frequency of the first passive repeater 21 to a predetermined frequency while maintaining the first passive repeater 21 at a predetermined length. As a result, the first non-feeding radiating element 21 for the high band is not extremely shortened, so that the coupling between the first non-feeding radiating element 21 and the feeding radiating element 10 can be enhanced. However, when it is not necessary to shorten the first passive repeater 21 so much in order to raise the resonance frequency of the first passive repeater 21 to a predetermined frequency, as in the antenna device 101B shown in FIG. 1 (B). In addition, the capacitor C may be omitted.

The power feeding radiating element 10 is directly fed from the power feeding circuit 1. The first non-feeding radiating element 21 is fed by electric field coupling of the feeding radiating element 10 with the main radiating element 11. The second non-feeding radiation element 22 is fed from the first non-feeding radiation element 21 via the coupling element 30.

The name of the "passive repeater" is a name meaning a radiant element that is not directly fed from the feeding circuit 1, and is indirectly fed as described above.

The inductor Ls makes it difficult for a high-frequency current in the high band of the communication frequency band to flow from the short-circuit line 14 to the ground side. As a result, the vicinity of the electric field coupling of the first non-feeding radiation element 21 is prevented from becoming an equivalent short circuit, and the first non-feeding radiation element 21 and the feeding radiation element 10 are compared with the case where the inductor Ls is not provided. Electric field coupling works more effectively. However, for example, when the electric field coupling between the first non-feeding radiation element 21 and the feeding radiation element 10 does not matter, the inductor Ls may not be provided as in the antenna device 101B shown in FIG. 1 (B).

FIG. 2A is a plan view of a main part of an electronic device 201 including an antenna device 101A, FIG. 2B is a side view thereof, and FIG. 2C is an antenna formed on a circuit board 40. It is a schematic circuit diagram of the apparatus 101A. FIG. 3 is a perspective view of a main part of an electronic device including the antenna device 101A. Further, FIG. 4 is a cross-sectional view of the electronic device 201 including the antenna device 101A.

As shown in FIG. 4, the electronic device 201 includes an antenna device 101A, a circuit board 40 on which a power feeding circuit connected to the antenna device 101A is formed, a housing 50 containing the antenna device 101A and the circuit board 40, and a housing 50. To be equipped.

As shown in FIGS. 2 (A), 2 (B), and 2 (C), the circuit board 40 includes a ground conductor forming region GR and a ground conductor non-forming region NGR. The antenna 41 is arranged at a position covering the ground conductor non-forming region NGR of the circuit board 40. The antenna 41 has a predetermined conductor pattern formed on a dielectric or an insulator. A feeding radiation element 10, a first non-feeding radiation element 21, and a second non-feeding radiation element 22 are formed on the surface of the antenna 41. The surface of the antenna 41 is a radiation element forming region. The smallest rectangular region surrounding the plurality of radiating elements formed in the plane may be used as the radiating element forming region. Further, the feeding radiation element 10, the first non-feeding radiation element 21, and the second non-feeding radiation element 22 are formed so as to be arranged in a plane direction, and the first non-feeding radiation element 21 is the power feeding radiation element 10 and the second non-feeding element 10. It is in a position sandwiched between the feeding radiation element 22 and the power feeding radiation element 22. Therefore, the feeding radiation element 10 and the second non-feeding radiation element 22 are located outside the radiation element forming region of the first non-feeding radiation element 21. The power feeding radiation element 10, the first non-feeding radiation element 21, and the second non-feeding radiation element 22 are conductor patterns such as Cu formed by, for example, the LDS method (Laser Direct Structuring).

According to this embodiment, an electronic device provided with a space-saving and high-gain antenna device can be obtained as compared with a structure in which each radiating element is formed on the circuit board 40.

Since the stray capacitance Cs shown in FIGS. 1 (A) and 1 (B) is generated between the conductor pattern constituting the main radiating element 11 and the conductor pattern constituting the sub radiating element 12, the main radiating element 11 is used. The size of the stray capacitance Cs can be adjusted by trimming the open end of the constituent conductor pattern or the conductor pattern constituting the sub-radiating element 12.

The power supply circuit 1 shown in FIGS. 1 (A), 1 (B), and 2 (C) is formed on the circuit board 40. Further, a coupling element 30, an inductor Ls, and a capacitor C are formed on the circuit board 40. (In the example shown in FIG. 2C, the chip capacitor C and the chip inductor Ls are mounted.) The coupling element 30 is a chip component (layered transformer) including the first coil L1 and the second coil L2. It is mounted on the circuit board 40.

As shown in FIG. 2C, in a state where the antenna 41 is mounted on the circuit board 40 and electrically connected, the feeding radiation element 10 formed on the antenna 41 is one end of the feeding circuit 1 and It is connected to one end of the chip inductor Ls. Further, the first non-feeding radiation element 21 is connected to one end of the chip capacitor C, and the second non-feeding radiation element 22 is the second non-feeding radiation element connection terminal PS2 of the coupling element 30 (FIGS. 1A and 1). B) is connected to).

The second non-feeding radiating element 22 extends non-parallel to the first non-feeding radiating element 21. Therefore, the second non-feeding radiation element 22 is mainly magnetically coupled to the first non-feeding radiation element 21 via the coupling element 30 without unnecessary electric field coupling.

According to the present embodiment, since the feeding radiation element 10 is an inverted F type radiation element, an antenna device having a small size and high radiation efficiency feeding radiation element can be obtained. Further, since the inductor Ls connected in series between the short-circuit line 14 of the inverted F type radiating element and the ground is provided, the feeding radiating element corresponding to communication in a low frequency band (for example, a low band described later) despite its small size. An antenna device having the above is obtained. In addition, in FIGS. 2A and 2C, an example in which a conductor pattern is not formed between the feeder line 13 and the short-circuit line 14 is shown, but a conductor pattern is formed in this portion. You may. That is, a continuous conductor pattern may be formed from the feeder line 13 to the short-circuit line 14.

Further, according to the present embodiment, since the second extending portion 11B extending in the direction away from the first non-feeding radiating element 21 from the connecting portion of the feeding line 13 to the inverted F type radiating element is provided, the feeding radiating element 10 has. Since most of the contribution to the radiation is located away from the first non-feeding radiation element 21, it is possible to prevent the radiation of the feeding radiation element 10 from being hindered by the first non-feeding radiation element 21. In other words, the influence of the first non-feeding radiating element 21 on the feeding radiating element 10 is small. Since the second non-feeding radiation element 22 is located at a position farther from the feeding radiation element 10 than the first non-feeding radiation element 21, the influence on the feeding radiation element 10 is further small. As a result, the radiation characteristics of the first non-feeding radiation element 21 and the second non-feeding radiation element 22 can be added to the radiation characteristics of the power supply radiation element 10 with almost no change in the radiation characteristics of the power supply radiation element 10.

Here, a circuit diagram of an antenna device as a comparative example is shown in FIG. The antenna device as a comparative example includes a feeding radiation element 60, a first non-feeding radiation element 71, a second non-feeding radiation element 72, and a coupling element 80. The first coil LA of the coupling element 80 is connected between the feeding radiation element 60 and the ground, and the second coil LB is connected between the first non-feeding radiation element 71 and the ground. The second non-feeding radiating element 72 is arranged in close proximity to the first non-feeding radiating element 71 for electric field coupling.

In the antenna device of the comparative example as shown in FIG. 14, a further non-feeding radiation element (second non-feeding radiation element 72) cannot be strongly coupled to the non-feeding radiation element (first non-feeding radiation element 71). It is difficult for the further non-feeding radiation element (second non-feeding radiation element 72) to receive sufficient power from the non-feeding radiation element (first non-feed radiation element 71). Therefore, the effect of widening the band by adding the second passive repeater 72 is small. Further, when the feeding radiation element 60 and the first non-feeding radiation element 71 are coupled by the coupling element 80 in this way, the first non-feeding radiation element 71 changes the radiation characteristics of the feeding radiation element 60.

Next, a configuration example of the coupling element 30 will be shown.

FIG. 5 is a perspective view of the coupling element 30, and FIG. 6 is an exploded plan view showing a conductor pattern formed in each layer of the coupling element 30.

The coupling element 30 of this embodiment is a rectangular parallelepiped chip component mounted on a circuit board in an electronic device. In FIG. 5, the outer shape of the coupling element 30 and the internal structure thereof are shown separately. The outer shape of the coupling element 30 is represented by a two-dot chain line. A first ground terminal PG1, a first non-feeding radiation element connection terminal PS1, a second ground terminal PG2, and a second non-feeding radiation element connection terminal PS2 are formed on the outer surface of the coupling element 30. Further, the coupling element 30 includes a first surface MS1 and a second surface MS2 which is a surface opposite to the first surface. In the present embodiment, the first surface MS1 is the mounting surface, and this surface faces the circuit board.

A first conductor pattern L11, a second conductor pattern L12, a third conductor pattern L21, and a fourth conductor pattern L22 are formed inside the coupling element 30. The first conductor pattern L11 and the second conductor pattern L12 are connected via an interlayer connection conductor V1. The third conductor pattern L21 and the fourth conductor pattern L22 are connected via an interlayer connection conductor V2. In FIG. 5, the insulating base materials S11, S12, S21, and S22 on which the conductor patterns are formed are shown separately in the stacking direction.

The first ground terminal PG1 and the first passive repeater connection terminal PS1 are terminals to which both ends of the first coil L1 are connected, and the first passive repeater connection terminal PS1 and the second ground terminal PG2 are of the second coil. It is a terminal to which both ends are connected.

As shown in FIG. 6, the insulating base material S11 has the first conductor pattern L11, the insulating base material S12 has the second conductor pattern L12, the insulating base material S21 has the third conductor pattern L21, and the insulating base material S22 has the fourth conductor. Patterns L22, respectively, are formed. In these coil conductor patterns, the insulating base materials S11, S12, are arranged so that the first conductor pattern L11, the second conductor pattern L12, the third conductor pattern L21, and the fourth conductor pattern L22 are arranged in order from the layer closest to the mounting surface. S21 and S22 are laminated. Note that FIG. 6 shows an insulating base material on which a coil conductor pattern is formed. In the coupling element 30 of the present embodiment, a plurality of insulating base materials having no coil conductor pattern formed are laminated below the insulating base material S11 and above the insulating base material S22, respectively.

The first end of the first conductor pattern L11 is connected to the first ground terminal PG1, and the second end is connected to the first end of the second conductor pattern L12 via the interlayer connection conductor V1. The second end of the second conductor pattern L12 is connected to the first non-feeding radiation element connection terminal PS1. Further, the first end of the third conductor pattern L21 is connected to the second non-feeding radiation element connection terminal PS2, and the second end of the third conductor pattern L21 is of the fourth conductor pattern L22 via the interlayer connection conductor V2. It is connected to the first end. The second end of the fourth conductor pattern L22 is connected to the second ground terminal PG2.

When the coupling element 30 is composed of a resin multilayer substrate, the insulating base materials S11, S12, S21, and S22 are, for example, liquid crystal polymer (LCP) sheets, and the conductor patterns L11, L12, L21, and L22 are, for example, copper foils. It was done. When the coupling element 30 is composed of a ceramic multilayer substrate, the insulating substrates S11, S12, S21, and S22 are, for example, low temperature co-fired ceramics (LTCC [Low Temperature Co-fired Ceramics]), and the conductor patterns L11 and L12. , L21 and L22 are, for example, printed and formed of copper paste.

FIG. 7 is a circuit diagram of the coupling element 30 including the above four coil conductor patterns. The second conductor pattern L12 and the first conductor pattern L11 are connected in series to form the first coil L1. Similarly, the fourth conductor pattern L22 and the third conductor pattern L21 are connected in series to form the second coil L2. The first coil L1 and the second coil L2 are electromagnetically coupled.

With the above configuration, the conductor patterns L11, L12, L21, and L22 overlap over the entire circumference in a plan view, and the conductor patterns L11, L12, L21, and L22 are closest to each other in the stacking direction (other insulating base materials). The coupling coefficient between the first coil L1 and the second coil L2 is high because the first coil L1 and the second coil L2 are adjacent to each other in the stacking direction.

It is also possible to appropriately adjust the coupling coefficient to an appropriate value via another insulating base material on which a conductor pattern is not formed.

FIG. 8 is a diagram showing the frequency characteristics of the reflection coefficient of the antenna device 101A. Here, the horizontal axis is the frequency, and the vertical axis is the reflection loss (S11) of the antenna device 101A as seen from the feeding circuit 1. In FIG. 8, resonance points are generated at frequencies f11, f12, f21, and f22. Here, the frequency f11 is the resonance frequency of the main radiation element 11 in the first frequency band F1, and the frequency f12 is the resonance frequency of the sub-radiation element 12. This frequency f12 is a resonance frequency in the second frequency band F2, which has a higher frequency than the first frequency band. Further, the frequency f21 is the resonance frequency of the first passive radiating element 21, and the frequency f22 is the resonance frequency of the second passive radiating element 22.

The first frequency band F1 is, for example, a low band communication frequency band from 700 MHz to 960 MHz, and the second frequency band F2 is a high band communication frequency band, for example, from 1700 MHz to 2700 MHz. In this example, the resonance of the main radiating element 11 is used for low band communication, and the resonance of the sub radiating element 12 is used for high band communication such as the 1800 MHz band. Further, the resonance of the resonance frequency f22 of the second non-feeding radiation element 22 and the resonance of the resonance frequency f21 of the first non-feeding radiation element 21 are used for high-band communication in a region higher than f12. As described above, the feeding radiation element 10 has a resonance frequency in both the first frequency band F1 and the second frequency band F2, and the first non-feeding radiation element 21 and the second non-feeding radiation element 22 have a second frequency band F2. Has a resonance frequency.

The resonance frequency f22 of the second non-feeding radiation element 22 is defined between the resonance frequency f21 of the first non-feed radiation element 21 and the resonance frequency f12 in the second frequency band of the power supply radiation element 10. Therefore, the resonance frequency of the first non-feeding radiation element 21 from the resonance frequency of the feeding radiation element 10 (particularly, the resonance frequency f12 of the sub-radiation element 12 in this embodiment, that is, the resonance frequency in the second frequency band of the feeding radiation element 10). The antenna devices 101A and 101B can be used over a wide band continuous up to f21. Further, since the second non-feeding radiation element 22 is located outside the radiation element forming region (a position electrically separated from the power supply circuit 1) with respect to the first non-feeding radiation element 21, radiation is not easily hindered. Therefore, the second passive repeater 22 effectively contributes to widening the bandwidth.

In addition to the basic resonance frequency (λ / 4 resonance) of the main radiation element 11, a higher-order resonance mode such as 3λ / 4 resonance may be used. Further, the high frequency band can be similarly widened for the inverted F type radiating element in which the feeding radiating element does not include the sub radiating element.

<< Second Embodiment >>
In the second embodiment, an example in which the first non-feeding radiation element and the feeding radiation element are electrically coupled to each other at the tip portions will be described.

FIG. 9 is a circuit diagram of the antenna device 102 according to the second embodiment. The antenna device 102 includes a first non-feeding radiating element 21, a second non-feeding radiating element 22, a feeding radiating element 10, and a coupling element 30.

The first coil L1 of the coupling element 30 is connected between the first passive repeater 21 and the ground, and the second coil L2 is connected between the second passive repeater 22 and the ground.

The tip portions of the first non-feeding radiating element 21 and the feeding radiating element 10 are close to each other. Further, the tip of the first non-feeding radiation element 21 and the tip of the feeding radiation element 10 extend in the same direction. However, the extending direction of the feeding radiation element 10 from the connection portion (feeding point) of the feeding line and the extending direction of the first non-feeding radiation element 21 from the coupling element 30 are opposite. The first non-feeding radiating element 21 and the feeding radiating element 10 are electrically coupled to each other mainly at a portion where the tip portions are close to each other (a portion surrounded by a broken line in the drawing).

The power feeding radiating element 10 is directly fed from the power feeding circuit 1. The first non-feeding radiating element 21 is fed by electric field coupling with the feeding radiating element 10. The second non-feeding radiation element 22 is fed from the first non-feeding radiation element 21 via the coupling element 30.

The power feeding radiation element 10 is used for communication in the first frequency band (for example, low band from 700 MHz to 960 MHz) due to its 1/4 wavelength resonance, and is high in the second frequency band (for example, 1700 MHz to 2700 MHz) due to its 3/4 wavelength resonance. Used for band) communication. Further, the resonance of the first passive repeater 21 and the resonance of the second passive repeater 22 are used for communication in the second frequency band.

As described above, since the tip of the power feeding radiating element 10 (the end far from the connection portion of the feeder line) and the tip of the first non-feeding radiating element 21 are portions having strong electric field strength, the first non-feeding is supplied. Even if the parallel running distance between the tip of the radiating element 21 and the tip of the feeding radiating element 10 is short, the feeding radiating element 10 and the first non-feeding radiating element 21 can be strongly coupled.

10 (A) is a plan view of a main part of an electronic device 202 including an antenna device 102, and FIG. 10 (B) is a side view thereof.

The electronic device 202 includes an antenna device 102, a circuit board 40 on which a power feeding circuit connected to the antenna device 102 is formed, and a housing for accommodating the antenna device 102 and the circuit board 40. The housing is not shown in FIGS. 10 (A) and 10 (B).

The circuit board 40 includes a ground conductor forming region GR and a ground conductor non-forming region NGR. The antenna 41 is arranged at a position covering the ground conductor non-forming region NGR of the circuit board 40. The antenna 41 has a predetermined conductor pattern formed on a dielectric or an insulator. A feeding radiation element 10, a first non-feeding radiation element 21, and a second non-feeding radiation element 22 are formed on the surface of the antenna 41. The power feeding radiation element 10, the first non-feeding radiation element 21, and the second non-feeding radiation element 22 are conductor patterns such as Cu formed by, for example, the LDS method (Laser Direct Structuring).

The power supply circuit 1 shown in FIG. 9 is formed on the circuit board 40. Further, a coupling element 30 is formed on the circuit board 40. The coupling element 30 is a chip component including the first coil L1 and the second coil L2, and is mounted on the circuit board 40.

The feeding radiation element 10 formed on the antenna 41 is connected to one end of the feeding circuit 1 in a state where the antenna 41 is mounted on the circuit board 40 and is electrically connected. Further, the first non-feeding radiation element 21 and the second non-feeding radiation element 22 are connected to the coupling element 30.

As shown in FIG. 10A, in the radiation element forming region of the feeding radiation element 10, the first non-feeding radiation element 21, and the second non-feeding radiation element 22, the second non-feeding radiation element 22 is the first non-feeding element 22. It is located outside the feed radiating element 21. According to this structure, the radiation efficiency of the second passive repeater 22 is higher than that of the first passive repeater 21, so that the resonance frequency in the second frequency band of the passive repeater 10 and the first passive repeater 21 The gain in the frequency band between the resonance frequency and the frequency band is increased, and the second frequency band is effectively widened.

Further, as shown in FIG. 10A, the feeding radiation element 10 is arranged at a position farther from the ground conductor forming region GR than the first non-feeding radiation element 21. According to this structure, the radiation efficiency of the long wire feeding radiation element 10 connected to the power feeding circuit 1 is increased.

<< Third Embodiment >>
In the third embodiment, an example in which the feeding radiation element is a loop-shaped radiation element will be described.

FIG. 11 is a circuit diagram of the antenna device 103 according to the third embodiment. The antenna device 103 includes a first non-feeding radiation element 21, a second non-feeding radiation element 22, a feeding radiation element 10, and a coupling element 30.

The end of the power feeding radiating element 10 opposite to the connection end of the power feeding circuit 1 is connected to the ground via the impedance adjusting circuit 15. Since a loop is formed by the feeding radiation element 10, the impedance adjusting circuit 15, the ground, and the feeding circuit 1, the feeding radiation element 10 can be said to be a loop-shaped radiation element. The feeding radiation element 10 is formed at a position surrounding the first non-feeding radiation element 21 and the second non-feeding radiation element 22.

The first non-feeding radiating element 21 and the feeding radiating element 10 have a portion extending in the same direction (a portion in which the first non-feeding radiating element 21 and the feeding radiating element 10 run in parallel), and the extending portion thereof. The first non-feeding radiating element 21 is electrically coupled to the feeding radiating element 10.

The power feeding radiating element 10 is directly fed from the power feeding circuit 1. The first non-feeding radiating element 21 is fed by electric field coupling of the feeding radiating element 10 with the main radiating element 11. The second non-feeding radiating element 22 is fed from the first non-feeding radiating element 21 via the coupling element 30.

The fed radiation element 10 is used for communication in the first frequency band (for example, a low band from 700 MHz to 960 MHz), and the first passive repeater 21 and the second passive repeater 22 are used in the second frequency band (for example, from 1700 MHz to 2700 MHz). Used for high band) communication.

The impedance adjusting circuit 15 has a high impedance in the high band, and the tip end portion (the end portion on the side far from the connection portion of the feeding circuit 1) of the feeding radiation element 10 is substantially opened. In other words, the reactance of the impedance adjusting circuit 15 is determined so that the tip of the feeding radiation element 10 is substantially open in the high band. Therefore, in the high band, the first passive repeater 21 and the second passive repeater 22 are not electrically surrounded by the loop. In other words, when the first non-feeding radiation element 21 and the second non-feeding radiation element 22 radiate, the feeding radiation element 10 is made to appear open by the impedance adjusting circuit 15. Therefore, in the high band, the first non-feeding radiation element 21 and the second non-feeding radiation element 22 act as radiation elements without being affected by the feeding radiation element 10. That is, the radiation efficiency of the first passive repeater 21 or the second passive repeater 22 alone is maintained.

According to this embodiment, the feeding radiation element 10 is connected between the feeding circuit 1 and the ground, and the first non-feeding radiation element 21 and the second non-feeding radiation element 22 are partially surrounded by the power feeding radiation element 10. Therefore, the first non-feeding radiation element 21 and the second non-feeding radiation element 22 can be arranged in a limited space together with the power feeding radiation element 10, and a small antenna device is configured.

<< Fourth Embodiment >>
In the fourth embodiment, an example of an antenna device including three or more non-feeding radiation elements and two or more coupling elements will be shown.

FIG. 12 is a circuit diagram of the antenna device 104 according to the fourth embodiment. The antenna device 104 includes a feeding radiation element 10, a first non-feeding radiation element 21, a second non-feeding radiation element 22, a third non-feeding radiation element 23, and coupling elements 30A and 30B.

The antenna device 104 of the present embodiment includes a third non-feeding radiation element 23 and two coupling elements 30A and 30B, unlike the examples shown in FIGS. 1 (A) and 1 (B).

The coupling element 30A includes a first coil L1 and a second coil L2 that is electromagnetically coupled (mainly magnetically coupled) to the first coil L1. The coupling element 30B includes a third coil L3 and a fourth coil L4 that is electromagnetically coupled (mainly magnetically coupled) to the third coil L3.

The first coil L1 of the coupling element 30A is connected between the first passive repeater 21 and the ground. A series circuit of the second coil L2 of the coupling element 30A and the third coil L3 of the coupling element 30B is connected between the second non-feeding radiation element 22 and the ground. The fourth coil L4 of the coupling element 30B is connected between the third passive repeater 23 and the ground.

The feed radiation element 10 is an inverted F type radiation element including a main radiation element 11, a sub radiation element 12, a feed line 13, and a short circuit line 14. A feeding circuit 1 is connected between the feeding line 13 and the ground via a capacitor C. Inductors Ls are connected in series between the short-circuit line 14 and the ground.

The configuration of the power feeding radiating element 10 is as shown in the first embodiment. The configuration of the first non-feeding radiation element 21 and the second non-feeding radiation element 22 is the same as that of the first non-feeding radiation element 21 and the second non-feeding radiation element 22 shown in the first embodiment.

FIG. 13 is a diagram showing the frequency characteristics of the reflection coefficient of the antenna device 104. Here, the horizontal axis is the frequency, and the vertical axis is the reflection loss (S11) of the antenna device 104 as seen from the feeding circuit 1. In FIG. 13, resonance points are generated at frequencies f11, f12, f21, f22, and f23. Here, the frequency f11 is the resonance frequency of the main radiation element 11 in the first frequency band F1, and the frequency f12 is the resonance frequency of the sub-radiation element 12. This frequency f12 is a resonance frequency in the second frequency band F2, which has a higher frequency than the first frequency band. Further, the frequency f21 is the resonance frequency of the first non-feeding radiation element 21, the frequency f22 is the resonance frequency of the second non-feed radiation element 22, and the frequency f23 is the resonance frequency of the third non-feed radiation element 23.

The first frequency band F1 is, for example, a low band communication frequency band from 700 MHz to 960 MHz, and the second frequency band F2 is a high band communication frequency band, for example, from 1700 MHz to 2700 MHz. In this example, the resonance of the main radiating element 11 is used for low band communication, and the resonance of the sub radiating element 12 is used for high band communication such as the 1800 MHz band. Further, the resonance of the resonance frequency f21 of the first non-feeding radiation element 21, the resonance of the resonance frequency f22 of the second non-feeding radiation element 22, and the resonance of the resonance frequency f23 of the third non-feeding radiation element 23 are higher than the above f12. Used for high band communication in the region.

As described above, the feeding radiation element 10 has a resonance frequency in both the first frequency band F1 and the second frequency band F2, and the first non-feeding radiation element 21, the second non-feeding radiation element 22, and the third non-feeding radiation element 10 have resonance frequencies. The radiating element 23 has a resonance frequency in the second frequency band F2.

By providing three or more non-feeding radiation elements in this way, and by providing a coupling element connected to each non-feeding radiation element, a wider band can be further achieved.

As a matter of course, the antenna device in the present invention can be used not only for transmission but also for reception or transmission / reception, and works in the same manner even if transmission / reception has an opposite relationship. The "feeding circuit" is not limited to a circuit that outputs transmission power, and corresponds to a circuit that inputs and amplifies a reception signal at the time of reception.

Further, the electronic device in the present invention is not limited to the electronic devices 201 and 202 already shown. For example, the electronic device provided with the antenna device shown in the third embodiment and the fourth embodiment is also included in the electronic device in the present invention.

Finally, the description of the embodiments described above is exemplary in all respects and not restrictive. Modifications and changes can be made as appropriate for those skilled in the art. The scope of the present invention is indicated by the scope of claims, not by the above-described embodiment. Further, the scope of the present invention includes modifications from the embodiment within the scope of the claims and within the scope of the claims.

C ... Capacitor GR ... Ground conductor forming region L1, LA ... 1st coil L2, LB ... 2nd coil L3 ... 3rd coil L4 ... 4th coil L11 ... 1st conductor pattern L12 ... 2nd conductor pattern L21 ... 3rd conductor Pattern L22 ... 4th conductor pattern Ls ... inductor MS1 ... 1st surface MS2 ... 2nd surface NGR ... ground conductor non-forming region PG1 ... 1st ground terminal PG2 ... 2nd ground terminal PS1 ... ... Second non-feeding radiation element connection terminals S11, S12, S21, S22 ... Insulating base material V1, V2 ... Interlayer connection conductor 1 ... Power supply circuit 10, 60 ... Power supply radiation element 11, 71 ... Main radiation element 11A ... First extension Part 11B ... 2nd stretched part 11C ... 3rd stretched part 11D ... 4th stretched part 12, 72 ... Sub-radiating element 13 ... Feeding line 14 ... Short-circuit line 15 ... Impedance adjusting circuit 21 ... 2 Non-feeding radiation elements 30, 30A, 30B, 80 ... Coupling element 40 ... Circuit board 41 ... Antenna 50 ... Housing 101A, 101B, 102, 103, 104 ... Antenna device 201, 202 ... Electronic equipment

Claims (19)

A first coupling element including a first coil and a second coil that couples to the first coil,
Power supply circuit and
Feeding radiation element and
The first passive repeater and
With a second passive repeater
The feeding radiation element is connected to the feeding circuit and is connected to the feeding circuit.
The first coil is connected between the first passive repeater and the ground.
The second coil is connected between the second passive repeater and the ground.
The first non-feeding radiating element is fed by electric field coupling with the feeding radiating element.
The second non-feeding radiating element is fed via the first coupling element.
Antenna device. The open end of the first non-feeding radiating element and a part of the feeding radiating element are electrically coupled without passing through another conductor.
The antenna device according to claim 1. The minimum distance between the open end of the second passive radiating element and the open end of the first passive radiating element is compared with the minimum distance between the open end of the first passive radiating element and the fed radiating element. is seperated,
The antenna device according to claim 1 or 2. The first coupling element is an element in which a plurality of insulating base materials and a plurality of conductor patterns are laminated.
The plurality of conductor patterns are formed on the surface of the plurality of insulating substrates.
The first coil and the second coil are formed by one or more conductor patterns among the plurality of conductor patterns.
The antenna device according to any one of claims 1 to 3 . The feeding radiation element and the first non-feeding radiation element have portions extending in the same direction as each other.
The antenna device according to any one of claims 1 to 4 . The power feeding radiating element resonates in the first frequency band and the second frequency band having a higher frequency than the first frequency band.
The first passive repeater and the second passive repeater resonate in the second frequency band.
The antenna device according to any one of claims 1 to 5 . The resonance frequency of the second non-feeding radiating element is between the resonance frequency of the feeding radiating element in the second frequency band and the resonance frequency of the first unfed radiating element.
The antenna device according to claim 6 . The feeding radiation element, the first non-feeding radiation element, and the second non-feeding radiation element are formed so as to be arranged in a plane direction, and the first non-feeding radiation element is the power feeding radiation element and the second non-feeding radiation element. The antenna device according to claim 7 , which is located between the two. The ground is a ground conductor
The antenna device according to any one of claims 1 to 8 , wherein the feeding radiation element is arranged at a position farther from the ground conductor than the first non-feeding radiation element. The feed radiation element is an inverted F type radiation element having a feed line and a short circuit line.
The antenna device according to any one of claims 1 to 8 . An inductor provided in series between the short circuit wire and ground.
The antenna device according to claim 10 . The antenna device according to claim 10 or 11 , wherein the feeding radiation element has a portion extending in a direction away from the first non-feeding radiation element from the connection portion of the feeding line of the feeding radiation element. The feeding radiation element is connected between the feeding circuit and the ground,
The first non-feeding radiation element and the second non-feeding radiation element were partially surrounded by the power feeding radiation element.
The antenna device according to any one of claims 1 to 8 . An impedance adjustment circuit connected between the power feeding radiation element and the ground is provided.
The impedance of the impedance adjusting circuit at the resonance frequency of the first non-feeding radiation element and the resonance frequency of the second non-feeding radiation element is higher than the impedance at the resonance frequency of the feeding radiation element.
The antenna device according to claim 1 3. A capacitor connected in series between the first passive repeater and the first coil is provided.
The antenna device according to claim 1 1 4. A second coupling element including a third coil and a fourth coil that couples to the third coil,
A third non-feeding radiating element, which is fed from the feeding circuit via the first coupling element and the second coupling element, is provided.
The third coil is connected between the second passive repeater and the ground.
The fourth coil is connected between the third passive repeater and the ground.
The antenna device according to claim 1 1 5. An electronic device comprising the antenna device according to any one of claims 1 to 16 , a circuit board on which the power feeding circuit connected to the antenna device is formed, and a housing for accommodating the antenna device and the circuit board. machine. The feeding radiation element, the first non-feeding radiation element, and the second non-feeding radiation element are conductor patterns formed on a dielectric or an insulator covering a part of the circuit board.
The electronic device according to claim 17 . The electronic device according to claim 17 or 18 , wherein the power feeding radiating element has a shape along the outer edge of the housing.

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