JP2016192684A - Antenna device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna device which is not easily affected by the surrounding environment and can be adjusted flexibly at each resonance frequency which has been double-resonated. SOLUTION: A substrate body 2 is provided with a patterned ground surface GND and first to third elements 5 on at least one of a front surface and a back surface of the substrate body, and the first element extends in the first direction. Part E1, second extension part E2, third extension part E3, and fourth extension part E4, the tip of the first element is connected to the ground plane, and the second element is The proximal end is connected to the distal end side of the one extending portion or the distal end of the third extending portion, and extends along the fourth extending portion. [Selection] Figure 1

Description

  The present invention relates to an antenna device that is less susceptible to the influence of the surrounding environment and that provides good characteristics.

  In recent years, there has been a demand for downsizing of an antenna, and development of an antenna that can obtain a wide bandwidth and high gain even if the antenna is small is in progress. For example, Patent Document 1 discloses a loading in which a loading inductance pattern and a frequency adjustment capacitance unit are connected in series to an antenna that has one end as a power supply port and the other end as a termination unit and resonates at a predetermined center frequency. The antenna module which connected the part is proposed.

On the other hand, conventionally, in a communication device, an antenna device using a radiation electrode and a dielectric block, an antenna device using a switch, and a control voltage source have been proposed to make the resonance frequency of the antenna double resonance.
For example, as a conventional technique using a dielectric block, Patent Document 2 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 3, 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. An antenna device has been proposed that includes a switch that is interposed between the end portion and electrically connects or disconnects the second radiation electrode with the first radiation electrode.

JP 2002-271123 A JP 2010-81000 A JP 2010-166287 A

However, the following problems remain in the above-described conventional technology.
That is, with the technique described in Patent Document 1, the antenna performance may not be sufficiently exerted depending on the material of the case of the device to be incorporated and the surrounding environment.
In addition, when performing double resonance, the technique using a dielectric block as described in Patent Document 2 uses a dielectric block that excites a radiation electrode. For each device, a dielectric block, a radiation electrode pattern, etc. There is a disadvantage that the design is required and the antenna performance is deteriorated depending on the design condition or unstable elements are increased. 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 3, a configuration of a control voltage source, a reactance circuit, and the like are necessary 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, is not easily affected by the surrounding environment, and can be adjusted flexibly for each resonance frequency that has been double-resonated. An object of the present invention is to provide an antenna device that can be secured inexpensively and easily and that can be reduced in size and thickness.

  The present invention employs the following configuration in order to solve the above problems. That is, an antenna device according to a first invention includes an insulating substrate body, and at least one of a front surface and a back surface of the substrate body, each having a ground surface and a first element patterned with a metal foil, A first element is provided with a feeding point on a proximal end side close to the ground surface and extends in a direction away from the ground surface, and a proximal end at a distal end of the first extending portion Are connected to each other and extend in a direction orthogonal to the first extension, and a direction orthogonal to the second extension from the tip of the second extension and the first extension A third extending portion extending in a direction opposite to the base end side of the existing portion; and a fourth extending portion extending along the second extending portion from the distal end of the third extending portion. The tip of the first element is connected to the ground plane.

  In the antenna device of the present invention, the tip of the first element is connected to the ground surface, and the second extending portion and the fourth extending portion are formed by the U-shaped portion of the first element extending from the second extending portion to the fourth extending portion. A stray capacitance is generated between the extending portion and the resonance frequency can be obtained even when a ground plane or a metal is placed close to the first element or the like, so that it can function as an antenna. .

An antenna device according to a second aspect of the present invention includes a second element patterned with a metal foil on at least one of a front surface and a back surface of the substrate body, and the second element is on a front end side of the first extending portion. Or the base end is connected to the front-end | tip of the said 3rd extension part, It is characterized by extending along the said 4th extension part.
That is, in this antenna device, since at least one of the front surface and the back surface of the substrate body is provided with the above-described ground surface, the first element, and the second element that are patterned with metal foil, By effectively utilizing each stray capacitance between the two, a double resonance can be achieved.
In particular, since the second element has a base end connected to the distal end side of the first extension part or the distal end of the third extension part and extends along the fourth extension part, the second element is mainly the first element. A resonance frequency different from the obtained resonance frequency can be obtained, and a double resonance can be achieved.

An antenna device according to a third invention is the antenna device according to the second invention, further comprising a third element patterned with metal foil on at least one of the front surface and the back surface of the substrate body, wherein the second element is the third element. A fifth extension extending from the tip of the extension in the same direction as the third extension; and a sixth extension extending from the tip of the fifth extension along the fourth extension. And the third element extends from a tip end of the first extending portion in a direction opposite to the second extending portion.
That is, in this antenna device, since the third element extends from the tip of the first extending portion in the direction opposite to the second extending portion, the resonance frequency and the main frequency obtained by the first element are mainly used. In addition, a resonance frequency different from the resonance frequency obtained by the second element can be obtained.

The antenna device according to a fourth aspect of the present invention is the antenna device according to the second or third aspect, wherein the first element extends in a direction away from the ground surface from the tip of the fourth extension. And an eighth extending portion extending from the distal end of the seventh extending portion toward the proximal end side of the fourth extending portion along the fourth extending portion and having the distal end connected to the ground surface. It is characterized by having.
That is, in this antenna device, the first element has the seventh extending portion and the eighth extending portion and has a folded shape. Therefore, the first element is connected to the ground surface and has a low impedance. The tip of the first element can be moved away from the tip of the second element, and the tip of the second element can have a higher impedance. In addition, the stray capacitance generated between the eighth extending portion and the fourth extending portion or the second element can achieve high performance mainly at the resonance frequency obtained by the second element. Furthermore, since the first element is folded, the size can be reduced.

The antenna device according to a fifth aspect of the present invention is the antenna device according to the fourth aspect, wherein the first element extends along the seventh extending portion from the middle of the fourth extending portion to the middle of the eighth extending portion. It has the 9th extension part which exists.
That is, in this antenna device, the first element has the ninth extending portion that extends along the seventh extending portion from the middle of the fourth extending portion to the middle of the eighth extending portion. , Stray capacitance is generated between the ninth extending portion and the seventh extending portion, which becomes the loading capacity adjustment pattern, and the resonance frequency obtained mainly from the base end of the first element to the ninth extending portion; Two resonance frequencies can be obtained, that is, the resonance frequency obtained mainly from the ninth extending portion to the tip of the eighth extending portion. Further, by adjusting the connection position of the ninth extending portion, it is possible to adjust the stray capacitance to be loaded, and it is possible to adjust the two resonance frequencies.

An antenna device according to a sixth invention is characterized in that, in any one of the second to fifth inventions, a tip of the second element is connected to the ground plane.
That is, in this antenna device, since the tip of the second element is connected to the ground surface, the impedance of the tip of the second element is reduced when the design conditions are easily affected by the relationship with surrounding components. The influence of surrounding parts can be suppressed.

An antenna device according to a seventh invention is characterized in that, in any one of the first to sixth inventions, an antenna element of a dielectric antenna is connected to the fourth extending portion.
That is, in this antenna device, the element length of the loading element that does not self-resonate at a desired resonance frequency can be shortened, the impedance can be increased, and the stray capacitance can be increased. In addition, the size and the antenna characteristics can be improved.
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.
In particular, since the antenna element of the dielectric antenna is connected to the fourth extending portion, a large stray capacitance can be generated between the second element and the third element.

An antenna device according to an eighth invention is characterized in that, in any one of the first to seventh inventions, a passive element is connected to the first extending portion.
That is, in this antenna device, it is possible to obtain an antenna device that can flexibly adjust each resonance frequency by selecting a passive element and can achieve 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.

The present invention has the following effects.
According to the antenna device of the present invention, the tip of the first element is connected to the ground surface, and the second extending portion is formed by the U-shaped portion of the first element extending from the second extending portion to the fourth extending portion. A stray capacitance is generated between the fourth extending portion, so that a resonance frequency can be obtained even when a ground plane or a metal is placed close to the first element or the like and function as an antenna. Can do.
In addition, by providing the ground surface, the first element, and the second element, which are patterned with metal foil, on at least one of the front surface and the back surface of the substrate body, it floats between each element and between the ground surfaces. Capacitance is generated, and multiple resonances can be achieved with at least two resonance frequencies.
In particular, since the second element has a base end connected to the distal end side of the first extension part or the distal end of the third extension part and extends along the fourth extension part, the second element is mainly the first element. A resonance frequency different from the obtained resonance frequency can be obtained, and a double resonance can be achieved.
In addition, each resonant frequency can be flexibly adjusted by selecting the antenna element and passive element connected to the element, so that multiple resonance 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 1st Embodiment of the antenna device which concerns on this invention, it is a top view which shows the positional relationship of each element. In 1st Embodiment, it is a wiring diagram which shows the main area | regions which contribute to each resonance frequency. FIG. 3 is a wiring diagram showing stray capacitance generated in the antenna device in the first embodiment. In 1st Embodiment, it is a perspective view (a) which shows an antenna element, a top view (b), a front view (c), and a bottom view (d). In 1st Embodiment, it is a graph which shows the VSWR characteristic (voltage standing wave ratio) at the time of making it 4 resonance. In 2nd Embodiment of the antenna apparatus which concerns on this invention, it is an exploded top view which shows the positional relationship of each element. In other embodiment of the antenna device which concerns on this invention, it is a top view which shows the positional relationship of each element.

  Hereinafter, a first embodiment of an antenna device according to the present invention will be described with reference to FIGS. 1 to 4.

  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 surface GND that is patterned on a surface of the substrate body 2 with a metal foil such as a copper foil. A first element 3, a second element 4, and a third element 5 are provided.

  The first element 3 includes a first extending portion E1 provided with a feeding point FP on the base end side close to the ground surface GND and extending in a direction away from the ground surface GND, and a first extending portion E1. A second extending portion E2 having a proximal end connected to the distal end and extending in a direction orthogonal to the first extending portion E1, and a direction orthogonal to the second extending portion E2 from the distal end of the second extending portion E2. A third extension E3 extending in a direction opposite to the base end side of the first extension E1, and a fourth extension extending from the tip of the third extension E3 along the second extension E2. And the existing portion E4.

  Note that the direction orthogonal to the first extending portion E1 is a direction along the end side of the ground surface GND facing the base end portion of the first extending portion E1, and the substrate body 2 facing this end side It is also a direction along one side. The direction away from the ground plane GND is the direction toward the one side of the substrate body 2.

The tip of the first element 3 is connected to the ground plane GND.
The second element 4 has a proximal end connected to the distal end of the third extending portion E3 and extends along the fourth extending portion E4.
That is, the second element 4 includes a fifth extending portion E5 extending from the tip of the third extending portion E3 in the same direction as the third extending portion E3, and a fourth extending from the tip of the fifth extending portion E5. And a sixth extending portion E6 extending along the existing portion E4.

The third element 5 extends from the tip of the first extending portion E1 in the direction opposite to the second extending portion E2.
The first element 3 includes a seventh extending portion E7 extending in a direction away from the ground surface GND from the tip of the fourth extending portion E4, and a fourth extending portion E4 from the tip of the seventh extending portion E7. And an eighth extending portion E8 extending toward the base end side of the fourth extending portion E4 and having a distal end connected to the ground surface GND. That is, the first element 3 has a shape that is folded in an inverted U shape. Note that the tip of the eighth extension E8 is connected to the ground plane GND.
The first element 3 has a ninth extending portion E9 extending along the seventh extending portion E7 from the middle of the fourth extending portion E4 to the middle of the eighth extending portion E8. That is, an annular portion is formed by the proximal end sides of the ninth extending portion E9 and the eighth extending portion E8, and the distal end sides of the seventh extending portion E7 and the fourth extending portion E4.

An antenna element AT of a dielectric antenna is connected to the fourth extending portion E4 on the way.
In addition, the first extending element E1 is connected to the first passive element P1 on the way.
The first element 3 includes a first ground pattern G1 having a proximal end connected to the distal end side with respect to the first passive element P1 of the first extending portion E1 and the other end connected to the ground surface GND, and a first extending portion E1. It has a second ground pattern G2 having a proximal end connected to the proximal end side of the first passive element P1 in the existing portion E1 and the other end connected to the ground plane GND.
A second passive element P2 is connected to the first ground pattern G1, and a third passive element P3 is connected to the second ground pattern G2. Thus, the first passive element P1, the second passive element P2, and the third passive element P3 constitute a π-type impedance adjustment circuit.

The board body 2 is a general printed board, and in the present embodiment, a printed board made of glass epoxy resin or the like is employed.
The feed point FP is connected to a feed point of a high frequency circuit (not shown). For example, a core wire of a coaxial cable (not shown) connected to a high-frequency circuit is connected to the feed point FP, and the ground wire of the coaxial cable is connected to a nearby ground plane GND. A high frequency circuit is mounted in the area of the ground plane GND.
For example, an inductor, a capacitor, a resistor, or a jumper line is used as each passive element.

The antenna element AT is a loading element that does not self-resonate at a desired resonance frequency, and is a chip antenna in which a conductor pattern 122 such as Ag is formed on the surface of a dielectric 121 such as ceramic as shown in FIG. is there. Both end portions of the conductor pattern 122 are connected to opposite ends of the divided portion of the fourth extending portion E4 for mounting, so that the antenna element AT becomes a part of the fourth extending portion E4.
As the antenna element AT, elements having different lengths, widths, conductor patterns, and the like may be selected according to the setting of the resonance frequency and the like. Depending on the desired frequency, the dielectric 121 used in the antenna element AT may be a magnetic material or a composite material in which a dielectric and a magnetic material are mixed.

The first element 3, the second element 4, and the third element 5 extend at a distance from each other so as to generate a stray capacitance between them and a stray capacitance between the ground plane GND. Yes.
That is, as shown in FIG. 3, the stray capacitance Ca between the eighth extending portion E8 and the sixth extending portion E6 and the stray capacitance between the ninth extending portion E9 and the seventh extending portion E7. Cb, the stray capacitance Cc between the fourth extension E4 and the eighth extension E8, the stray capacitance Cd between the sixth extension E6 and the fourth extension E4, and the fourth extension The stray capacitance Ce between the distal end side of the antenna element AT and the third element 5 in the existing portion E4, and the stray capacitance Ce ′ between the antenna element AT and the second extending portion E2 and the third element 5 The stray capacitance Ce ″ between the base end side of the antenna element AT and the second extending portion E2 in the fourth extending portion E4, and the floating between the second extending portion E2 and the ground plane GND. The capacitance Cf, the stray capacitance Cg between the fourth extending portion E4 and the ground plane GND, and the stray capacitance Ch between the third element 5 and the ground plane GND A sixth extending part E6 and stray capacitance Ci between the ninth extending portion E9 can be generated.
Note that, in the annular portion surrounded by the fourth extending portion E4, the seventh extending portion E7, the eighth extending portion E8, and the ninth extending portion E9, in addition to the stray capacitance Cb, the fourth extending portion Although the stray capacitance is generated between E4 and the eighth extending portion E8, the stray capacitance Cb is dominant in the annular portion due to the relationship between the stray capacitances Cc, Cg, and Ci.

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

  In the antenna device 1 of 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 from the lowest frequency. In order, double resonance is realized in four frequency bands.

Hereinafter, these resonance frequencies will be described in detail.
“About the first resonance frequency f1”
The frequency of the first resonance frequency f1 can be set and adjusted by the first element 3, the antenna element AT, and the stray capacitances Ca, Cb, Cc, Cd, Ce, Ce ′, Ce ″, Cf, Cg. it can.
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, Ce ′, Ce ″, Cf, Cg.
Furthermore, the final frequency adjustment can be flexibly performed by selecting the first passive element P1.
The final impedance adjustment can be flexibly performed by controlling the flow of the high-frequency current flowing on the first ground pattern G1 and the ground plane GND side by selecting the second passive element P2.
In this way, the first resonance frequency f1 is adjusted mainly at the portion of the one-dot chain line A1 in FIG.

“About the second resonance frequency f2”
The frequency of the second resonance frequency f2 is from the base ends of the second extending portion E2, the third extending portion E3, and the fourth extending portion E4 to the connecting portion of the ninth extending portion E9 and the stray capacitance Ca, It can be set and adjusted by Cb, Cd, Ce, Ce ′, Ce ″, Cf, and Cg.
Further, the impedance adjustment of the second resonance frequency f2 can be performed by setting each of the stray capacitances Ca, Cb, Cd, Ce, Ce ′, Ce ″, Cf, Cg.
Furthermore, the final frequency adjustment can be flexibly performed by selecting the first passive element P1.
The final impedance adjustment can be flexibly performed by controlling the flow of the high-frequency current flowing on the first ground pattern G1 and the ground plane GND side by selecting the second passive element P2.
In this way, the second resonance frequency f2 is adjusted mainly at the portion of the two-dot chain line A2 in FIG.

“About the third resonance frequency f3”
The frequency of the third resonance frequency f3 is the second element 4, the second extending portion E2, the third extending portion E3, and the stray capacitances Ca, Cb, Ce, Ce ′, Ce ″, Cg, Cf, Ci. And can be set and adjusted.
Further, the impedance adjustment of the third resonance frequency f3 can be performed by setting each of the stray capacitances Ca, Cb, Ce, Ce ′, Ce ″, Cg, Cf, and Ci.
Furthermore, the final frequency adjustment can be flexibly performed by selecting the first passive element P1.
The final impedance adjustment can be flexibly performed by controlling the flow of the high-frequency current flowing on the second ground pattern G2 and the ground plane GND side by selecting the third passive element P3.
In this way, the third resonance frequency f3 is adjusted mainly at the portion of the broken 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 and the stray capacitances Ce, Ce ′, Ce ″, Ch.
Moreover, the impedance adjustment of the fourth resonance frequency f4 can be performed by setting each of the stray capacitances Ce, Ce ′, Ce ″, Ch.
Furthermore, the final frequency adjustment can be flexibly performed by selecting the first passive element P1.
The final impedance adjustment can be flexibly performed by controlling the flow of the high-frequency current flowing on the second ground pattern G2 and the ground plane GND side by selecting the third passive element P3.
In this way, the fourth resonance frequency f4 is adjusted mainly at the portion indicated by the dotted line A4 in FIG.

  As described above, in the antenna device 1 of the present embodiment, the tip of the first element 3 is connected to the ground plane GND, and the U-shape of the first element 3 extending from the second extending portion E2 to the fourth extending portion E4. Since the stray capacitances Ce, Ce ′, Ce ″ are generated between the second extending portion E2 and the third element 5 and the fourth extending portion E4 by the portion, the ground plane is directly below the first element 3 and the like. Even if GND and metal are arranged close to each other, the resonance frequency can be obtained and the antenna can function as an antenna.

  Since the ground surface GND, the first element 3, the second element 4, and the third element 5 are formed on the surface of the substrate main body 2 with a metal foil, the gap between each element and the ground surface GND is provided. It is possible to make multiple resonances by effectively using each stray capacitance between them.

In particular, since the second element 4 has a base end connected to the third extending portion E3 and extends along the fourth extending portion E4, the resonance frequency f1 obtained mainly by the first element 3 is Another resonance frequency f3 can be obtained, and a double resonance can be achieved.
Further, since the third element 5 extends from the tip of the first extending portion E1 in the direction opposite to the second extending portion E2, the resonance frequency f1 obtained mainly by the first element 3 and the main In addition, a resonance frequency f4 different from the resonance frequency f3 obtained by the second element 4 can be further obtained.

  Also, since the first element 3 has a seventh extending portion E7 and an eighth extending portion E8 and has a folded shape, the first element 3 is connected to the ground plane GND and has a low impedance. The tip of the second element 4 can be moved away from the tip of the second element 4, and the tip of the second element 4 can have a higher impedance. Further, the stray capacitances Cc and Ca generated between the eighth extending portion E8, the fourth extending portion E4, and the second element 4 have high performance mainly at the resonance frequency f3 obtained by the second element 4. Can be realized. Furthermore, since the first element 3 is folded, the size can be reduced. Since the first element 3 is folded, the tip of the first element 3 is on the side opposite to the tip of the third element 5, and the open end of the third element 5 can be increased in impedance.

  Furthermore, since the first element 3 has the ninth extending portion E9 extending along the seventh extending portion E7 from the middle of the fourth extending portion E4 to the middle of the eighth extending portion E8. The stray capacitance Cb is generated between the ninth extending portion E9 and the seventh extending portion E7, which becomes the loading capacity adjustment pattern, and is obtained mainly from the base end of the first element 3 to the ninth extending portion E9. The two resonance frequencies of the resonance frequency f2 obtained and the resonance frequency f1 obtained mainly from the ninth extending portion E9 to the tip of the eighth extending portion E8 can be obtained. In addition, by adjusting the connection position of the ninth extending portion E9, the stray capacitances Cb and Ci to be loaded can be adjusted, and the two resonance frequencies can be adjusted.

In addition, the antenna element AT, which is a loading element that does not self-resonate at a desired resonance frequency, can shorten the element length, increase the impedance, and increase the stray capacitance. It is possible to improve the antenna characteristics.
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.
In particular, since the antenna element AT of the dielectric antenna is connected to the fourth extending portion E4, a large stray capacitance can be generated between the second element 4 and the third element 5.

  Further, by selecting the first passive element P1, 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.

  Next, a second embodiment of the antenna device according to the present invention will be described below with reference to FIG. Note that, in the following description of the embodiment, the same components described in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted.

The difference between the second embodiment and the first embodiment is that, in the first embodiment, the tip of the first element 3 is connected to the ground plane GND, and the tips of the second element 4 and the third element 5 are open ends. However, in the antenna device 21 of the second embodiment, as shown in FIG. 6, the tips of the second element 4 and the third element 5 are also connected to the ground plane GND. Note that the tips of the second element 4 and the third element 5 are connected to the ground plane GND through, for example, a through hole formed in the substrate body 2.
As described above, in the second embodiment, since at least one tip of the second element 4 and the third element 5 is also connected to the ground plane GND, it is easily affected by the relationship with surrounding parts depending on design conditions, etc. By reducing the impedance of the tip of the second element 4 or the third element 5, the influence of surrounding parts can be suppressed.

  Next, the results of measuring the VSWR characteristics (voltage standing wave ratio) of an example in which the antenna device of the above embodiment is actually manufactured will be described with reference to FIG.

In these measurements, the following passive elements were used.
First passive element P1: 1.0 nH inductor Second passive element P2: 3.9 nH inductor Third passive element P3: 0.5 pF capacitor

As can be seen from this measurement result, the first to fourth resonance frequencies f1 to f4 are obtained with a good bandwidth.
Note that the frequency of the first resonance frequency f1 is 879.1 MHz. The frequency of the second resonance frequency f2 is 1789.2 MHz. The frequency of the third resonance frequency f3 is 2140.4 MHz. Further, the frequency of the fourth resonance frequency f4 is 2612.0 MHz.

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

For example, in each of the above embodiments, the antenna element is provided in the fourth extending portion, but the antenna element is provided in the sixth extending portion or the third element to shorten the element, thereby reducing the overall size of the apparatus. It does not matter.
Moreover, in each said embodiment, although the passive element was connected to the 1st extension part, you may connect to another element and extension part. For example, you may connect a passive element to the front-end | tip part of a 1st element.

In addition, as described above, it is preferable to connect the antenna element to be a part of the element. However, the antenna element may not be connected, and may be a fourth extending portion that is extended only by a metal foil such as a copper foil. . At this time, in order to increase the impedance, at least a part of the fourth extending part is formed into a narrow pattern narrower than the other parts, or a meander pattern extending in a fixed direction as a whole while zigzag is folded back. It is preferable.
Furthermore, when there is a margin in the substrate size, a part of the element may be replaced with a pattern in which a linear or plate-like metal is folded. Moreover, you may make it the pattern swirled in shapes, such as a spiral shape, using a through hole with respect to the front and back of the same board | substrate body.

  In each of the above embodiments, the ground plane, the ground pattern, the first element, the second element, and the third element are formed on one substrate body, but the substrate body is located on the base end side of the first extension portion. The substrate portion on which the first element, the second element, and the third element are removed, and the substrate portion on which the ground surface, the base end side of the first extension portion, the ground pattern, and the impedance adjustment circuit are formed. You may divide | segment into two board | substrate parts and install these by electrically connecting with each other by a connection wiring etc.

  As another example of the above embodiment, as shown in FIG. 7, the first extending portion E1 to the fourth extending portion E4 may be used without folding the first element 23. In this other example, the antenna element AT is not connected to the fourth extending portion E4. In this case, the effect of folding the first element and the effect of connecting the antenna element AT cannot be obtained, but the overall size can be reduced.

  DESCRIPTION OF SYMBOLS 1,21 ... Antenna apparatus, 2 ... Board | substrate main body, 23 ... 1st element, 4 ... 2nd element, 5 ... 3rd element, AT ... Antenna element, E1 ... 1st extension part, E2 ... 2nd extension Present part, E3 ... third extension part, E4 ... fourth extension part, E5 ... fifth extension part, E6 ... sixth extension part, E7 ... seventh extension part, E8 ... eighth extension part , E9, Ninth extension, FP, feeding point, G1, first ground pattern, G2, second ground pattern, GND, ground plane, P1, first passive element, P2, second passive element, P3, first. 3 passive elements

Claims (8)

An insulating substrate body;
A ground surface and a first element patterned with metal foil on at least one of the front surface and the back surface of the substrate body,
The first element is based on a first extending portion provided with a feeding point on a proximal end side close to the ground surface and extending in a direction away from the ground surface, and on a distal end of the first extending portion. A second extension portion connected to an end thereof and extending in a direction orthogonal to the first extension portion; and a direction orthogonal to the second extension portion from a tip of the second extension portion, wherein the first extension portion A third extending portion extending in a direction opposite to the base end side of the extending portion, and a fourth extending portion extending along the second extending portion from the distal end of the third extending portion. And
The antenna device, wherein a tip of the first element is connected to the ground plane. The antenna device according to claim 1,
A second element patterned with a metal foil is provided on at least one of the front and back surfaces of the substrate body,
The second element has a proximal end connected to a distal end side of the first extending portion or a distal end of the third extending portion, and extends along the fourth extending portion. apparatus. The antenna device according to claim 2, wherein
At least one of the front surface and the back surface of the substrate body includes a third element patterned with a metal foil,
The second element includes a fifth extending portion extending from the tip of the third extending portion in the same direction as the third extending portion, and the fourth extending portion from the tip of the fifth extending portion. A sixth extending portion extending along the
The antenna device, wherein the third element extends in a direction opposite to the second extending portion from a tip end of the first extending portion. In the antenna device according to claim 2 or 3,
The first element extends from the tip of the fourth extension part in a direction away from the ground surface, and along the fourth extension part from the tip of the seventh extension part. And an eighth extension portion extending toward the base end side of the fourth extension portion and having a distal end connected to the ground surface. The antenna device according to claim 4, wherein
The first element has a ninth extending portion extending along the seventh extending portion from the middle of the fourth extending portion to the middle of the eighth extending portion. Antenna device to do. In the antenna device according to any one of claims 2 to 5,
An antenna device, wherein a tip of the second element is connected to the ground plane. In the antenna device according to any one of claims 1 to 6,
An antenna device, wherein an antenna element of a dielectric antenna is connected to the fourth extending portion. In the antenna device according to any one of claims 1 to 7,
An antenna device, wherein a passive element is connected to the first extending portion.