JP2014003504A - Antenna device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna device capable of flexibly adjusting resonance frequencies forming a double resonance state.SOLUTION: An antenna device includes: a substrate body; a ground pattern GND formed on a surface of the substrate body; and first to third elements 3 to 5. In the first element, a feeding point FP is provided at the base end side. The first element extends in a constant direction with first passive elements P1a, P1b and an antenna element AT connected with a middle part of the first element. The second element extends along the first element with a base end of the second element connected with the base end side of the first element. A third element includes at least a fifth extending part E5 extending in a direction opposite to the first element.

Description

  The present invention relates to an antenna device capable of making multiple resonances.

2. Description of the Related Art Conventionally, in communication equipment, an antenna device using a radiation electrode and a dielectric block, an antenna device using a switch, and a control voltage source has been proposed to make the resonance frequency of the antenna double resonant.
For example, as a conventional technique using a dielectric block, Patent Document 1 proposes a composite antenna that achieves high efficiency by forming a radiation electrode on a resin molded body and further integrating the dielectric block with an adhesive. .

  Further, as a conventional technique using a switch and a control voltage source, in Patent Document 2, a first radiation electrode, a second radiation electrode, a middle portion of the first radiation electrode, and a base of the second radiation electrode are disclosed. There has been proposed an antenna device including a switch interposed between the end portions and electrically connecting or disconnecting the second radiating electrode with the first radiating electrode.

JP 2010-81000 A JP 2010-166287 A

However, the following problems remain in the above-described conventional technology.
That is, in the technique using the dielectric block as described in Patent Document 1, a dielectric block that excites the radiation electrode is used, and it is necessary to design the dielectric block, the radiation electrode pattern, etc. for each device. Depending on design conditions, antenna performance may be degraded, and unstable elements may increase. In addition, since the radiation electrode is formed on the surface of the resin molding, it is necessary to design the radiation electrode pattern on the resin molding. Depending on the communication equipment to be mounted and its application, the antenna design and mold design This is necessary and causes a significant increase in cost. Furthermore, since the dielectric block and the molded resin are integrated with an adhesive, the antenna performance may be degraded or unstable depending on the adhesive conditions (adhesive thickness, adhesive area, etc.) in addition to the adhesive Q value. There is a disadvantage that the number of elements increases.
In addition, in the case of an antenna device using a switch and a control voltage source as described in Patent Document 2, a configuration of a control voltage source, a reactance circuit, and the like are required to switch the resonance frequency with the switch. However, there is a problem in that each device is complicated, there is no degree of freedom in design, and easy antenna adjustment is difficult.

  The present invention has been made in view of the above-mentioned problems, and can flexibly adjust each resonance frequency that has been double-resonated. It is an object of the present invention to provide an antenna device that can be thinned.

  The present invention employs the following configuration in order to solve the above problems. That is, the antenna device according to the first invention includes an insulating substrate body, and a ground pattern, a first element, a second element, and a third element, each of which is patterned with a metal foil on the surface of the substrate body. The first element is provided with a feeding point on the base end side close to the ground pattern, and the first passive element and the antenna element of the dielectric antenna are connected in this order and extend in a certain direction. The second element has a base end connected to the base end side of the first element, and a second passive element is connected midway and extends along the first element, and the third element is One end is connected to the base end side of the first element, and at least a portion extending in the direction opposite to the first element is provided.

  Since this antenna apparatus includes not only the first element and the second element but also the third element, it becomes possible to perform double resonance at at least three resonance frequencies. In particular, since the third element extends in the opposite direction to the first element, interference between the resonance frequency obtained mainly from the third element and the resonance frequency obtained mainly from the first element can be reduced.

The antenna device according to a second aspect of the present invention is the antenna device according to the first aspect, wherein the first element extends in a certain direction from a base end to the first passive element, and the first passive element. A second extending portion extending in the extending direction of the first extending portion by extending the antenna element from the middle, and extending from the tip of the second extending portion toward the second element side A third extending portion that extends between the second extending portion and the second element from the tip of the third extending portion and extends along the second extending portion. It has the 4th extension part connected to the base end side of 2 extension parts, or the 1st extension part, It is characterized by the above-mentioned.
That is, in this antenna device, an annular loading pattern (hereinafter referred to as an opening loading portion) capable of effectively generating stray capacitance inside and outside is configured at the open end portion of the first element, so that an antenna element having high impedance can be obtained. Compared with the case where becomes an open end, it is possible to suppress the influence of the surrounding human body and peripheral parts and prevent the antenna performance from deteriorating.

Specific stray capacitances include stray capacitance between the fourth extension and the second element, stray capacitance between the fourth extension and the ground pattern, and the inside of the loading pattern (second The stray capacitance between the extension portion and the fourth extension portion) and the stray capacitance between the antenna element and the ground can be generated, and at least the resonance frequency obtained mainly from the first element and the second element A high degree of freedom in adjustment can be obtained at each resonance frequency with respect to the resonance frequency obtained mainly, and at the same time, both the antenna performance and the reduction of the influence of the human body and peripheral parts can be achieved.
Therefore, by effectively utilizing the internal and external combined stray capacitance due to the loading pattern having the loading element antenna element that does not self-resonate at a desired resonance frequency, it is possible to achieve multiple resonances, It is also possible to reduce the influence.

Furthermore, by selecting the antenna element and the passive element, it is possible to flexibly adjust each resonance frequency, and it is possible to obtain an antenna device capable of making multiple resonances according to design conditions. Thus, since each resonance frequency can be flexibly adjusted in terms of the antenna configuration, the resonance frequency can be switched, and the adjustment location by a passive element or the like can be changed according to the application or device.
In addition, it is possible to design in the plane of the substrate body, and it is possible to reduce the thickness compared to the case of using a conventional dielectric block or resin molded body, and by selecting an antenna element that is a dielectric antenna, Miniaturization and high performance are possible. Further, there is no need for costs due to molds, design changes, etc., and low costs can be realized.

An antenna device according to a third invention is the antenna device according to any one of the second invention, wherein the third element is a portion extending in a direction opposite to the first element, and the fifth extension. It has the 6th extension part which is connected to the tip of an existing part and extends in the direction orthogonal to the fixed direction and the 2nd element side.
That is, in this antenna device, the third element has a sixth extending portion connected to the tip of the fifth extending portion and extending in the direction orthogonal to the predetermined direction and on the second element side. Even when the antenna occupation area on the substrate body is narrow and it is difficult to extend the third element in the extending direction of the fifth extending portion, it is possible to extend the antenna by changing the direction at the sixth extending portion. Performance (radiation efficiency, bandwidth) can be improved.

An antenna device according to a fourth invention is the antenna device according to the second or third invention, further comprising a fourth element patterned on the surface of the substrate body with a metal foil, wherein the fourth element is the first extension portion. Extending in the direction perpendicular to the certain direction and toward the second element.
That is, in this antenna device, since the fourth element extends from the middle of the first extending portion in the direction orthogonal to the certain direction and toward the second element, the resonance frequency mainly consisting of the fourth element is As a result, four double resonances can be realized by the first to fourth elements. In addition, it becomes possible to widen a bandwidth by making a 4th element into a wide part.

An antenna device according to a fifth invention is characterized in that, in the third invention, the ground pattern is arranged closer to a base end side of the fifth extending portion than a tip end of the sixth extending portion. To do.
That is, in this antenna device, since the ground pattern is arranged closer to the proximal end side of the fifth extending portion than the distal end of the sixth extending portion, the distance between the ground pattern and the distal end of the sixth extending portion is As a result, the influence of the ground pattern can be reduced. In the case where the fourth element is provided, the distance between the ground pattern and the tip of the fourth element is also increased, and the influence of the ground pattern can be reduced also in the fourth element.

An antenna device according to a sixth invention is the antenna device according to the fourth invention, wherein the first extending portion has an interference control portion protruding along the fourth element between the fourth element and the ground pattern. It is characterized by that.
That is, in this antenna device, since the first extending part has the interference control part protruding along the fourth element between the fourth element and the ground pattern, the fourth element, the interference control part, During this period, stray capacitance is generated, and the influence of the human body and peripheral parts can be reduced. Further, when the third element has the sixth extension portion, and because the stray capacitance interposed between the fourth element and the sixth extension portion is in the vicinity of the feeding point, the fourth element side Compared with the case where the 6th extension part E side interferes directly, it becomes possible to reduce an influence.

An antenna device according to a seventh invention is characterized in that, in any one of the second to sixth inventions, the fourth extending portion is connected to a proximal end side of the second extending portion. .
That is, in this antenna device, since the fourth extending portion is connected to the proximal end side of the second extending portion, an annular structure constituted by the first extending portion and the second to fourth extending portions. This loading pattern is separated through the first passive element, and the frequency can be easily adjusted by suppressing the return of the high-frequency current from the loading pattern to the first extending portion.

The antenna device according to an eighth aspect of the present invention is the antenna device according to any one of the second to seventh aspects, wherein the first extending portion is formed with a notch portion disposed to face the base end portion of the second extending portion. It is characterized by being.
That is, in this antenna device, the first extending portion is formed with a notch portion disposed opposite to the base end portion of the second extending portion, so that the gap between the notched portion and the second extending portion is formed. The stray capacitance is generated in accordance with the cutout area of the cutout portion, and the cutout portion functions as a capacitance control portion. Interference between the fourth element side and the first element side can be suppressed by the capacity control portion of the notch.

An antenna device according to a ninth invention includes the main substrate according to any one of the first to eighth inventions, wherein a main ground portion electrically connected to the ground pattern is patterned with a metal foil on a surface thereof. It is characterized by being.
That is, in this antenna device, the main ground part electrically connected to the ground pattern is provided with a main board having a pattern formed of a metal foil on the surface, so that a high frequency circuit or the like is provided on the main ground part side of the main board. The substrate body can be downsized. In addition, it is possible to install the board body above the main board, and the degree of freedom of installation in the housing of the device is improved. Furthermore, in order to respond flexibly to the arrangement conditions of the housing to be mounted, it is possible to employ a flexible substrate or the like for the substrate body separately from the main substrate. In addition, a spacer made of a high dielectric constant material or a rubber material can be inserted between the substrate body and the main substrate, so that the effect of reducing the size of the conductor pattern (each element) and the impact absorption effect can be obtained.

The present invention has the following effects.
According to the antenna device of the present invention, the third element extends in the opposite direction to the first element, thereby reducing interference between the resonance frequency obtained mainly from the third element and the resonance frequency obtained mainly from the first element. can do. In addition, by forming an annular loading pattern that can effectively generate stray capacitance inside and outside at the open end of the first element, it is possible to make multiple resonances with high antenna performance and to influence the human body and peripheral parts Can also be reduced.
Furthermore, by selecting the antenna element and the passive element, each resonance frequency can be adjusted flexibly, so that multiple resonances can be achieved according to design conditions, and miniaturization and high performance can be achieved.
Therefore, the antenna device of the present invention can easily achieve multiple resonances corresponding to various applications and devices, and can save space.

In one Embodiment of the antenna device which concerns on this invention, it is a top view which shows the positional relationship of each element. In this embodiment, it is a wiring diagram which shows the stray capacitance produced with an antenna apparatus. In this embodiment, they are a perspective view (a), a plan view (b), a front view (c), and a bottom view (d) showing an antenna element. In this embodiment, it is a simplified sectional view showing an antenna device. In this embodiment, it is a graph which shows the VSWR characteristic (voltage standing wave ratio) at the time of making 4 resonance in a free space state and a human body wearing state. In this embodiment, it is a graph which shows the radiation pattern of an antenna device.

  Hereinafter, an embodiment of an antenna device according to the present invention will be described with reference to FIGS.

As shown in FIGS. 1 and 2, the antenna device 1 according to the present embodiment includes an insulating substrate body 2 and a ground pattern GND formed by patterning a metal foil such as a copper foil on the surface of the substrate body 2. The first element 3, the second element 4, the third element 5, and the fourth element 6 are provided.
In addition, as shown in FIG. 4, the antenna device 1 includes a main substrate 2B in which a main ground portion G2 electrically connected to the ground pattern GND by a connection wiring 11 is patterned on a surface with a metal foil such as a copper foil. It has.

  The substrate body 2 has a substantially long plate shape and is installed above the main substrate 2B. Between the substrate body 2 and the main substrate 2B, an insulating property formed of a general resin such as ABS is used. A spacer S is inserted. The main ground portion G2 is also provided directly below the substrate body 2.

The first element 3 is provided with a feeding point FP on the base end side close to the ground pattern GND, and two first passive elements P1a and P1b and a dielectric antenna antenna element AT are connected in this order. Extend in a certain direction. Here, the certain direction is an extending direction of the substrate body 2. The two first passive elements P1a and P1b are connected in series via the land portion.
The second element 4 has a base end connected to the base end side of the first element 3, and a second passive element P <b> 2 is connected midway and extends along the first element 3.

  The first element 3 includes a first extending portion E1 extending in a certain direction from the base end to the first passive elements P1a and P1b, and an antenna element AT from the first passive elements P1a and P1b. A second extending portion E2 extending in the extending direction of the first extending portion E1, and a third extending portion E3 extending from the tip of the second extending portion E2 toward the second element 4 side. The tip of the third extension E3 is between the second extension E2 and the second element 4 from the tip of the third extension E3 and extends along the second extension E2. The tip of the second extension E2 is the base of the second extension E2. It has the 4th extension part E4 connected to the end side.

That is, a loading pattern capable of effectively generating stray capacitance inside and outside is configured at the open end portion of the first element 3 by the second to fourth extending portions E2 to E4 connected in a ring shape.
The first extending portion E1 extends from the base end serving as the feeding point FP to the distal end to which the first passive element P1b is connected, extending in a substantially strip shape that is wide in the certain direction (the extending direction of the substrate body 2). Yes.
A portion on the base end side of the first extending portion E1 (the base end side from the notch portion E1a) extends in a direction perpendicular to the certain direction when viewed partially, and the first element 3 and The direction is orthogonal to the second element 4. Moreover, since it is arrange | positioned so that it may become a reverse direction with respect to the 3rd element 5 and the 4th element 6, and it has arrange | positioned in the vicinity of the feeding point FP, The entire occupied area can be expanded without interference, and the antenna performance (such as broadening the band) can be improved.
Moreover, although the loading pattern from the 1st extension part E1 and the 2nd extension part E2 to the 4th extension part E4 is electrically connected via 1st passive element P1a, P1b, as a pattern, Are separated by first passive elements P1a and P1b.

The third extending portion E3 extends in a direction orthogonal to the extending direction of the second extending portion E2 and the fourth extending portion E4, and the second extending portion E2 and the fourth extending portion E4 are , Longer than the third extending portion E3.
The second element 4 extends in the same direction as the loading pattern from the corner of the tip of the first extending portion E1 provided wider than the loading pattern.

  The third element 5 has one end connected to the base end side of the first element 3 and a fifth extending portion E5 extending in the opposite direction to the first element 3, and the fifth extending portion E5. A sixth extending portion E6 connected to the tip and extending in the direction orthogonal to the predetermined direction and extending toward the second element 4;

The fourth element 6 extends from the middle of the first extending portion E1 in a direction orthogonal to the predetermined direction and toward the second element 4, and has a wide portion wider than the line width of the second element 4. Has been.
The ground pattern GND is arranged closer to the base end side of the fifth extending portion E5 than the tip end of the sixth extending portion E6. The ground pattern GND is connected to the main ground portion G2, and is formed in a rectangular pattern.

The first extending part E1 is formed wider than the second extending part E2, and a notch part E1a disposed opposite to the base end part of the second extending part E2 is formed on the second extending part E2 side. Is formed.
The first extending part E1 has an interference control part E1b protruding along the fourth element 6 between the fourth element 6 and the ground pattern GND.
That is, the sixth extending portion E6, the fourth element 6, and the interference control portion E1b extend in the same direction.
The sixth extending portion E6 and the fourth element 6 extend in the same direction with a space therebetween, and the fifth extending portion E5 extending therebetween has a rectangular recess. E5a is formed. A ground pattern GND is disposed in the recess E5a.

The board body 2 and the main board 2B are general printed boards, and in the present embodiment, printed boards made of glass epoxy resin or the like are employed.
The feeding point FP is connected to a high frequency circuit (not shown) provided in the main ground portion G2 of the main board 2B.

  The antenna element AT is a loading element that does not self-resonate at a desired resonance frequency. For example, as shown in FIG. 3, the antenna element AT is a chip antenna in which a conductor pattern 22 such as Ag is formed on the surface of a dielectric 21 such as ceramics. is there. As the antenna element AT, elements having different lengths, widths, conductor patterns 22 and the like may be selected according to the setting of the resonance frequency or the like, and the same element may be selected.

Each of the elements extends at a distance from each other so as to generate a stray capacitance between them and a stray capacitance between the ground pattern GND or the main ground portion G2.
That is, as shown in FIG. 2, the stray capacitance Ca between the fourth extending portion E4 and the second element 4, the stray capacitance Cb between the fourth extending portion E4 and the ground pattern GND, and the loading pattern , The stray capacitance Cc between the antenna element AT and the main ground portion G2, and the cutout portion E1a (capacitance control) (in the second extension portion E2 and the fourth extension portion E4). Part) and the second extension part E2, the stray capacitance Cf between the first extension part E1 and the ground pattern GND, and between the first extension part E1 and the main ground part G2. Stray capacitance Cg, stray capacitance Ch between the fourth element 6 and the main ground portion G2, stray capacitance Ci between the fourth element 6 and the interference control portion E1b, the fifth extending portion E5 and the main Stray capacitance Cj between ground part G2 A floating capacitance Ck between the sixth extension portion E6 and the ground pattern GND, and the stray capacitance Cm between the sixth extension portion E6 and the main ground portion G2 can be generated.

  As the first passive elements P1a and P1b, the second passive element P2, and the third passive element P3, for example, jumper wires, inductors, capacitors, or resistors are employed.

  Next, each resonance frequency in the antenna device of the present embodiment will be described with reference to FIGS.

In the antenna device 1 according to the present embodiment, as shown in FIG. 5, the first resonance frequency f1, the second resonance frequency f2, the third resonance frequency f3, and the fourth resonance frequency f4 are double-resonated. Is done.
The first resonance frequency f1 is in a low frequency band among the four resonance frequencies, and mainly the first element 3 (the first extension portion E1 and the second to fourth extension portions serving as the loading pattern). E2 to E4) and stray capacitance. The second resonance frequency f2 is an intermediate frequency band among the four resonance frequencies, and is mainly determined by the second element 4, the second passive element P2, and the stray capacitance. The third resonance frequency f3 is an intermediate frequency band different from the second resonance frequency f2 among the four resonance frequencies, and is mainly determined by the fourth element 6 and the stray capacitance. Further, the fourth resonance frequency f4 is in a high frequency band among the four resonance frequencies, and is mainly determined by the third element 5 and the stray capacitance.

Further, final impedance adjustment is performed for each resonance frequency by controlling the flow of the high-frequency current flowing on the ground pattern GND side using the third passive element P3.
Hereinafter, these resonance frequencies will be described in more detail.

“About the first resonance frequency f1”
The frequency of the first resonance frequency f1 includes a loading pattern (second to fourth extending portions E2 to E4, antenna element AT, first passive elements P1a and P1b), first extending portion E1 and stray capacitance Ca, It can be set and adjusted by Cb, Cc, Cd, Ce, Cf, and Cg.
Further, the impedance adjustment of the first resonance frequency f1 can be performed by setting each of the stray capacitances Ca, Cb, Cc, Cd, Ce, Cf, and Cg.

Further, the final frequency adjustment can be flexibly performed by selecting the first passive elements P1a and P1b.
The final impedance adjustment can be flexibly performed by selecting the third passive element P3.
In this way, the resonance frequency and impedance can be flexibly adjusted by the “antenna element AT”, “each element length”, “passive element”, and “each stray capacitance”. That is, the first resonance frequency f1 is adjusted mainly at the portion indicated by the broken line A1 in FIG.

“About the second resonance frequency f2”
The frequency of the second resonance frequency f2 can be set and adjusted by the second element 4, the first extending portion E1, and the stray capacitances Ca, Cb, Ce, Cf, and Cg.
The impedance adjustment of the second resonance frequency f2 can be performed by setting each of the stray capacitances Ca, Cb, Ce, Cf, and Cg.
Further, the final frequency adjustment can be flexibly performed by selecting the second passive element P2.

The final impedance adjustment can be flexibly performed by selecting the third passive element P3.
In this manner, the resonance frequency and impedance can be flexibly adjusted by “each wiring pattern”, “passive element”, and “each stray capacitance”. That is, the second resonance frequency f2 is adjusted mainly at the portion of the dashed-dotted line A2 in FIG.

“About the third resonance frequency f3”
The frequency of the third resonance frequency f3 can be set and adjusted by the fourth element 6, the first extension E1, and the stray capacitances Cf, Cg, Ch, Ci.
Further, the impedance adjustment of the third resonance frequency f3 can be performed by setting each of the stray capacitances Cf, Cg, Ch, and Ci.

The final impedance adjustment can be flexibly performed by selecting the third passive element P3.
In this manner, the resonance frequency and impedance can be flexibly adjusted by “each wiring pattern”, “passive element”, and “each stray capacitance”. That is, the third resonance frequency f3 is adjusted mainly at a portion indicated by a two-dot chain line A3 in FIG.

“About the fourth resonance frequency f4”
The frequency of the fourth resonance frequency f4 can be set and adjusted by the third element 5, the first extending portion E1, and the stray capacitances Cf, Cj, Ck, Cm.
The impedance adjustment of the fourth resonance frequency f4 can be performed by setting each of the stray capacitances Cf, Cj, Ck, and Cm.

The final impedance adjustment can be flexibly performed by selecting the third passive element P3.
In this manner, the resonance frequency and impedance can be flexibly adjusted by “each wiring pattern”, “passive element”, and “each stray capacitance”. That is, the fourth resonance frequency f4 is adjusted mainly at the portion indicated by the dotted line A4 in FIG.

Next, the loading pattern portion will be described.
The loading pattern is formed in a loop shape including the antenna element AT by the second extending portion E2 to the fourth extending portion E4 provided on the distal end side of the first extending portion E1, and the first element 3 is opened. This is an open load portion designed to load a composite capacity at the end portion. A composite capacity image in the loading pattern portion is shown in FIG.

  In addition, when only the loading part by the antenna element AT is connected to the front end side of the first extension part E1, the open end part becomes high impedance and is easily affected by the human body and peripheral parts. In some cases, sufficient performance cannot be secured. On the other hand, when the opening pattern structure including the antenna element AT as in the present embodiment is connected to the distal end side of the first extending portion E1, it is an open end, but a decrease in impedance is minimized. At the same time, the stray capacitance in the opening loading portion (loading pattern) can suppress the influence of the human body and peripheral parts.

The fourth extending portion E4 is disposed so as to be able to generate the stray capacitance Ca between the second element 4 and is configured to load the composite capacitance with respect to the fourth resonance frequency f4 by the second element 4 as well. Is desirable.
Further, in order to achieve both the antenna performance and the reduction in the influence of the human body and peripheral parts, it is better that the area of the loading pattern is larger. In addition, if it is the same area, it is desirable to set the length of the 2nd extension part E2 and the 4th extension part E4 longer than the length of the 3rd extension part E3.

Next, the capacity control unit by the notch E1a will be described.
By forming the notch portion E1a on the distal end side of the first extending portion E1 (near the first passive element P1b), the area cut out between the base end side of the second extending portion E2 and the notch portion E1a A capacity control unit can be provided in accordance with the above.
In the case of the present embodiment, in order to suppress interference with the third element 5 that designs the fourth resonance frequency f4, the cutout portion E1a is formed to provide the capacitance control portion, and the first extension portion E1 is formed. doing.
Note that the capacity is increased as the area of the capacity control portion by the notch E1a is smaller (the interval is narrower), and the antenna performance such as the bandwidth of the first resonance frequency f1 is improved.

Next, the interference control unit E1b will be described.
The interference control part E1b is formed in the vicinity of the feeding point FP and protruding toward the fourth element 6 side of the first extension part E1.
The third resonance frequency f3 is mainly designed by the wide fourth element 6, but the fourth resonance frequency f4 also has a sixth extension E6 that extends in the same direction as the fourth element 6. Designed mainly with 3 elements 5. For this reason, the 4th element 6 and the 6th extension part E6 mutually interfere depending on distance, and there exists a tendency for antenna performance to deteriorate.

Therefore, in the present embodiment, the interference control unit E1b is provided in the vicinity of the fourth element 6, and the stray capacitance Ci with the fourth element 6 is generated. Thereby, since the stray capacitance Ci is interposed between the fourth element 6 and the sixth extending portion E6 and is in the vicinity of the feeding point FP, the influence can be reduced as compared with the case of direct interference.
The interference control unit E1b is more likely to generate the stray capacitance Ci with the fourth element 6 as the protrusion amount is longer. In addition, the stray capacitance Ci can reduce the influence of the human body and peripheral parts.

As described above, since the antenna device 1 according to the present embodiment includes the third element 5 as well as the first element 3 and the second element 4, it becomes possible to perform double resonance at at least three resonance frequencies. . In particular, the third element 5 extends in the opposite direction to the first element 3 to reduce interference between the resonance frequency obtained mainly from the third element 5 and the resonance frequency obtained mainly from the first element 3. it can.
In addition, by forming an annular loading pattern that can effectively generate stray capacitance inside and outside at the open end portion of the first element 3, compared with the case where the antenna element AT having a high impedance becomes the open end, The antenna performance can be prevented from deteriorating by suppressing the influence of the human body and peripheral parts.

Further, the stray capacitance between the fourth extending portion E4 and the second element 4, the stray capacitance between the fourth extending portion E4 and the ground pattern GND, and the inside of the loading pattern (second extending portion E2). Stray capacitance between the antenna element AT and the main ground portion G2, and at least a resonance frequency obtained mainly from the first element 3, and the stray capacitance between the antenna element AT and the main ground portion G2. It is possible to obtain a high degree of freedom in adjustment at each resonance frequency with the resonance frequency obtained mainly from the second element 4, and to achieve both the antenna performance and the reduction of the influence of the human body and peripheral parts.
Therefore, by effectively utilizing the internal and external composite stray capacitance by the above loading pattern having the loading element antenna element AT that does not self-resonate at a desired resonance frequency, it is possible to make a double resonance, and the human body and peripheral parts. It is also possible to reduce the influence of.

Furthermore, by selecting the antenna element AT and the passive element, it is possible to flexibly adjust each resonance frequency and to obtain an antenna device capable of making multiple resonances according to design conditions. Thus, since each resonance frequency can be flexibly adjusted in terms of the antenna configuration, the resonance frequency can be switched, and the adjustment location by a passive element or the like can be changed according to the application or device.
In addition, the design can be made in the plane of the substrate body 2, and the thickness can be reduced as compared with the case where a conventional dielectric block or resin molding is used, and the antenna element AT which is a dielectric antenna is selected. Thus, miniaturization and high performance can be achieved. Further, there is no need for costs due to molds, design changes, etc., and low costs can be realized.

  Further, since the third element 5 has the sixth extending portion E6 connected to the tip of the fifth extending portion E5 and extending in the direction orthogonal to the predetermined direction and on the second element 4 side, the substrate Even when the antenna occupying area on the main body 2 is narrow and it is difficult to extend the third element 5 in the extending direction of the fifth extending portion E5, the direction is changed and extended by the sixth extending portion E6. Thus, antenna performance (radiation efficiency, bandwidth) can be improved.

  Further, since the fourth element 6 extends from the middle of the first extending portion E1 in the direction orthogonal to the predetermined direction and toward the second element 4, a resonance frequency mainly including the fourth element 6 is obtained. Thus, the first to fourth elements 3 to 6 enable four double resonances. Further, since the fourth element 6 is a wide portion wider than the line width of the second element 4, the bandwidth can be increased.

  Further, since the ground pattern GND is arranged closer to the proximal end side of the fifth extending portion E5 than the distal end of the sixth extending portion E6, the distance between the ground pattern GND and the distal end of the sixth extending portion E6 is increased. As a result, the influence of the ground pattern GND can be reduced. Note that the distance between the ground pattern GND and the tip of the fourth element 6 is also increased, and the influence of the ground pattern GND can be reduced also in the fourth element 6.

  Moreover, since the 1st extension part E1 has the interference control part E1b which protruded along the 4th element 6 between the 4th element 6 and the ground pattern GND, the 4th element 6 and the interference control part The stray capacitance Ci is generated between E1b and the influence of the human body and peripheral parts can be reduced. Further, since the stray capacitance Ci interposed between the fourth element 6 and the sixth extending part E6 is in the vicinity of the feeding point FP, the fourth element 6 side and the sixth extending part E6 side directly interfere with each other. Compared with the case where it does, it becomes possible to reduce an influence.

Moreover, since the 4th extension part E4 is connected to the base end side of the 2nd extension part E2, it is comprised by the 1st extension part E1 and the 2nd-4th extension part E2-E4. The annular loading pattern is separated via the first passive elements P1a and P1b, and the frequency can be easily adjusted by suppressing the return of the high-frequency current from the loading pattern to the first extending portion E1.
Moreover, since the notch part E1a opposingly arranged with the base end part of the 2nd extension part E2 is formed in the 1st extension part E1, between the notch part E1a and the 2nd extension part E2 The stray capacitance is generated according to the area of the cutout E1a, and the cutout E1a functions as a capacitance control unit. Interference between the fourth element 6 side and the first element 3 side can be suppressed by the capacity control portion of the notch E1a.

  Further, since the main ground portion G2 electrically connected to the ground pattern GND is provided with the main substrate 2B patterned on the surface with metal foil, a high frequency circuit or the like is provided on the main ground portion G2 side of the main substrate 2B. The substrate body 2 can be reduced in size. Moreover, it becomes possible to install the board body 2 above the main board 2B, and the degree of freedom of installation in the housing of the device is improved. Furthermore, in order to flexibly cope with the arrangement conditions of the housing to be mounted, it is possible to adopt a flexible substrate or the like for the substrate body 2 separately from the main substrate 2B. Further, it becomes possible to insert a spacer S made of a high dielectric constant material or a rubber material between the substrate body 2 and the main substrate 2B, so that a conductor pattern (each element) can be miniaturized and an impact absorbing effect can be obtained. Can do.

  Next, with respect to an example in which the antenna device of this embodiment was actually manufactured, the results of measuring the VSWR characteristics (voltage standing wave ratio) and the results of measuring the radiation pattern at each resonance frequency are shown in FIG. This will be described with reference to FIG.

First, the VSWR characteristics for a case where the human body and surrounding parts are in a free space state and a case where the human body is virtually attached to a plastic bottle containing physiological saline having the same salt concentration as the human body. The results of measuring (voltage standing wave ratio) are shown in FIG.
In the measurement of FIG. 5, an inductor having L = 2.7 nH was used as the first passive element P1a, and an inductor having L = 8.2 nH was used as the first passive element P1b. Further, an inductor with L = 2.7 nH was used as the second passive element P2. Further, a capacitor of C = 15 pF was used as the third passive element P3.

As can be seen from this measurement result, even when the first to fourth resonance frequencies f1 to f4 obtained in the free space state are in the human body wearing state, the change in the resonance frequency is small and the fluctuation is suppressed. I understand that.
Typically, the case of the first resonance frequency f1 in the 900 MHz band and the second resonance frequency f2 in the 1800 MHz band will be described below.
First resonance frequency f1
<Free space state>
Resonance frequency: 873.1 MHz (VSWR = 1.4)
<Human body wearing state>
Resonance frequency: 789.1 MHz (VSWR = 1.60)
Second resonance frequency f2
<Free space state>
Resonance frequency: 1778.1 MHz (VSWR = 1.90)
<Human body wearing state>
Resonance frequency: 1640.1 MHz (VSWR = 1.60)

Next, FIG. 6 shows the measurement results of the radiation patterns at the first resonance frequency f1 and the second resonance frequency f2 for the antenna device of the above example.
Note that the extending direction of the antenna element AT (the extending direction of the second extending portion E2) is the Y direction, and the third extending portion E3 extends from the second extending portion E2 toward the fourth extending portion E4. The direction was the X direction, and the direction perpendicular to the surface of the substrate body 2 was the Z direction. At this time, vertical polarization, horizontal polarization, and power gain with respect to the YZ plane and ZX plane were measured. Moreover, this radiation pattern measurement was performed in the free space state.

  Note that the average power gain of the first resonance frequency f1 in the YZ plane was −3.5 dBi, and the average power gain of the second resonance frequency f2 was −7.4 dBi. In addition, the average power gain of the first resonance frequency f1 in the ZX plane was −5.2 dBi, and the average power gain of the second resonance frequency f2 was −4.0 dBi.

  In addition, this invention is not limited to the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.

For example, in the above embodiment, the main board is provided separately from the board main body, but an antenna device in which all the elements and the ground pattern are provided on one main board may be used.
In the above embodiment, the antenna element is provided only on the first element. However, the antenna element may be provided on the second element or the third element to shorten each element, thereby reducing the size of the entire apparatus. I do not care.

  DESCRIPTION OF SYMBOLS 1 ... Antenna apparatus, 2 ... Board | substrate main body, 2B ... Main board, 3 ... 1st element, 4 ... 2nd element, 5 ... 3rd element, 6 ... 4th element, AT ... Antenna element, E1 ... 1st extension Part, E1a ... notch part, E1b ... interference control part, E2 ... second extension part, E3 ... third extension part, E4 ... fourth extension part, E5 ... fifth extension part, E6 ... sixth Extension part, GND ... ground pattern, G2 ... main ground part, P1a, P1b ... first passive element, P2 ... second passive element, P3 ... third passive element, FP ... feeding point

Claims (9)

An insulating substrate body;
A ground pattern, a first element, a second element, and a third element each formed by patterning a metal foil on the surface of the substrate body;
The first element is provided with a feeding point on the proximal end side close to the ground pattern, and the first passive element and the antenna element of the dielectric antenna are connected in this order and extend in a certain direction.
The second element has a base end connected to the base end side of the first element and a second passive element connected in the middle and extends along the first element,
The third element includes at least a portion having one end connected to a proximal end side of the first element and extending in a direction opposite to the first element. The antenna device according to claim 1,
The first element extends from the base end to the first passive element in the predetermined direction, and the first extension part is arranged in the middle of the antenna element from the first passive element. A second extending portion extending in the extending direction, a third extending portion extending from the tip of the second extending portion toward the second element, and the tip of the third extending portion Between the second extending portion and the second element, and extending along the second extending portion, and a leading end thereof is on the proximal end side of the second extending portion or the first extending portion. An antenna device comprising: a connected fourth extending portion. The antenna device according to claim 2, wherein
A fifth extension part, wherein the third element is a part extending in a direction opposite to the first element;
An antenna apparatus comprising: a sixth extension portion connected to a tip of the fifth extension portion and extending in a direction orthogonal to the predetermined direction and extending toward the second element. In the antenna device according to claim 2 or 3,
Comprising a fourth element patterned with a metal foil on the surface of the substrate body;
The antenna device, wherein the fourth element extends from the middle of the first extending portion in a direction orthogonal to the predetermined direction and on the second element side. The antenna device according to claim 3, wherein
The antenna apparatus according to claim 1, wherein the ground pattern is arranged closer to a proximal end side of the fifth extending portion than a distal end of the sixth extending portion. The antenna device according to claim 4, wherein
The antenna device according to claim 1, wherein the first extending portion includes an interference control portion protruding along the fourth element between the fourth element and the ground pattern. In the antenna device according to any one of claims 2 to 6,
The antenna device, wherein the fourth extending portion is connected to a proximal end side of the second extending portion. In the antenna device according to any one of claims 2 to 7,
The antenna device according to claim 1, wherein a cutout portion is formed in the first extending portion so as to face the proximal end portion of the second extending portion. In the antenna device according to any one of claims 1 to 8,
An antenna device comprising: a main substrate having a main ground portion formed by patterning a metal foil on a surface of a main ground portion electrically connected to the ground pattern.