JPWO2018123345A1 - Antenna device - Google Patents

Abstract

The antenna device is miniaturized while securing isolation between the antennas. An antenna device (1) according to an embodiment of the present invention includes a ground conductor (GND1), a first antenna (ANT1), a second antenna (ANT2), and a loop portion (LP11). The first antenna (ANT1) and the second antenna (ANT2) are electrically connected to the ground conductor. The loop portion (LP11) includes a parasitic element (PE11) and a reactance element (RT11). The parasitic element (PE11) has an end (T10) electrically connected to the ground conductor (GND1). The parasitic element (PE11) has its end (T9) connected to the ground conductor (GND1) via the reactance element (RT11).

Description

  The present invention relates to an antenna apparatus provided with a plurality of antennas.

  An antenna device provided with a plurality of antennas is known. For example, Japanese Patent Application Laid-Open No. 2006-42111 (Patent Document 1) discloses an antenna apparatus provided with two antennas.

Unexamined-Japanese-Patent No. 2006-42111

  In an antenna apparatus provided with a plurality of antennas, it is necessary to secure isolation between the antennas. The isolation is a quantity that indicates the degree of signal leakage from one antenna element to the other between the antenna elements. The isolation is expressed as a ratio (dB) between the power of the input signal to one antenna element and the power of the leaked signal from one antenna element to the other antenna element.

  In the antenna device disclosed in Patent Document 1, the resonance phenomenon occurring in the loop path formed by the parasitic element and the ground plane reduces the current excited from one antenna to the other. As a result, isolation between the antennas is ensured.

  In the antenna device as disclosed in Patent Document 1, the resonant frequency of the loop path needs to be adjusted based on the frequency of the signal received by the antenna. The length of the parasitic element affects the inductance component of the parasitic element. Changing the length of the parasitic element changes the resonant frequency of the loop path. Therefore, changing the length of the parasitic element makes it difficult for the loop portion to resonate with the signal received by the antenna. The amount of signal transmitted from the antenna to the other antenna may increase and isolation between the antennas may be degraded. In the antenna device as disclosed in Patent Document 1, the parasitic element can be an obstacle to miniaturizing the antenna device while securing isolation between the antennas.

  The present invention has been made to solve the problems as described above, and an object thereof is to miniaturize an antenna device while securing isolation between the antennas.

  An antenna device according to an embodiment of the present invention includes a ground conductor, a first antenna and a second antenna, and a first loop portion. The first antenna and the second antenna are electrically connected to the ground conductor. The first loop portion includes a first parasitic element and a first reactance element. In the first parasitic element, one end of the first parasitic element is electrically connected to the ground conductor. In the first parasitic element, the other end of the first parasitic element is connected to the ground conductor via the first reactance element.

  The fact that one circuit element is "electrically connected" to another circuit element means that both are directly connected or indirectly connected via another circuit element other than the two. Means

  In the antenna device according to the present invention, the energy of the signal is consumed in the first loop portion by transmitting the signal received by the first antenna or the second antenna to the first loop portion. The power of the signal transmitted from one antenna to the other is reduced. As a result, isolation between antennas can be secured.

  In the antenna device according to the present invention, the other end of the first parasitic element is connected to the ground conductor via the first reactance element. The resonant frequency of the first loop portion can be adjusted by the length (inductance component) of the first parasitic element and the reactance of the first reactance element when designing the antenna device. Even when the first parasitic element is shortened, the antenna device can be designed such that the first loop portion resonates with the signal received by the first antenna by adjusting the reactance of the first reactance element. As a result, the antenna device can be miniaturized.

  According to the antenna device of the present invention, the antenna device can be miniaturized while securing isolation between the antennas.

FIG. 2 is a diagram showing an example of an equivalent circuit diagram of the antenna device according to Embodiment 1. It is a figure which shows an example of the external appearance of the antenna apparatus shown by FIG. It is a figure which shows the isolation characteristic of the antenna apparatus shown by FIG. FIG. 7 is a diagram showing an example of an equivalent circuit diagram of an antenna device according to a modification of the first embodiment. FIG. 7 is a diagram showing an example of an equivalent circuit diagram of an antenna device according to a second embodiment. It is a figure which shows an example of the external appearance of the antenna apparatus shown by FIG. FIG. 6 is a diagram collectively showing the isolation characteristics of the antenna device shown in FIG. 5 and the isolation characteristics of the antenna device shown in FIG. 1. FIG. 16 is a diagram showing an example of an equivalent circuit diagram of the antenna device according to Embodiment 3. It is a figure which shows an example of the external appearance of the antenna apparatus shown by FIG. It is a figure which shows the isolation characteristic of the antenna apparatus shown by FIG. 8, and the isolation characteristic of the antenna apparatus shown by FIG. 5 collectively. FIG. 16 is a diagram showing an example of an equivalent circuit diagram of the antenna device according to the fourth embodiment. It is a figure which shows an example of the external appearance of the antenna apparatus shown by FIG. FIG. 17 is a diagram showing an example of an equivalent circuit diagram of an antenna apparatus according to a first modification of the fourth embodiment. FIG. 21 is a diagram showing an example of an equivalent circuit diagram of an antenna apparatus according to a second modification of the fourth embodiment. FIG. 21 is a diagram showing an example of an equivalent circuit diagram of an antenna apparatus according to a third modification of the fourth embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals, and the description thereof will not be repeated in principle.

First Embodiment
FIG. 1 is a view showing an example of an equivalent circuit diagram of the antenna device 1 according to the first embodiment. The antenna device 1 can perform communication based on a plurality of communication methods. The antenna device 1 can perform communication in compliance with, for example, WiFi (registered trademark) (Wireless Fidelity) and Bluetooth (registered trademark) in 2400 to 2484 MHz (2.4 GHz band).

  As shown in FIG. 1, the antenna device 1 includes a ground conductor GND1, antennas ANT1 and ANT2, and a loop portion LP11. In FIG. 1, the ground conductor GND1 is drawn as a straight line connecting the feed points FP1 and FP2 in order to make it easy to understand the connection relationship between the components. The same applies to FIGS. 4, 5, 8, 11, and 13 to 15.

  The antenna ANT1 is connected to the ground conductor GND1 via the feeding point FP1. The antenna ANT2 is connected to the ground conductor GND1 via the feeding point FP2. The resonant frequency of the antenna ANT1 and the resonant frequency of the antenna ANT2 are close to each other.

  Loop portion LP11 includes a parasitic element PE11 and a reactance element RT11. The end T9 of the parasitic element PE11 is connected to the ground conductor GND1 via the reactance element RT11. The end T10 of the parasitic element PE11 is connected to the ground conductor GND1. Reactance element RT11 is connected to ground conductor GND1 at connection point N11. Reactance element RT11 includes an inductor L11. Reactance element RT11 may include a capacitor.

  In the loop portion LP11, a loop path is formed by the parasitic element PE11, the reactance element RT11, and the portion of the ground conductor GND1 from the connection point N11 to the end T12 of the parasitic element PE11.

  The capacitive coupling between the loop portion LP11 and the antenna ANT1 is stronger than the capacitive coupling between the loop portion LP11 and the antenna ANT2. The magnitude relationship in FIG. 1 is expressed by that the parasitic element PE11 and the antenna ANT1 are connected via the capacitor C1, while the parasitic element PE11 and the antenna ANT2 are not connected via the capacitor. ing.

  In the antenna device 1 including the antennas ANT1 and ANT2, it is necessary to secure the isolation between the antennas ANT1 and ANT2. In the antenna device 1, the signal received by the antenna ANT1 or ANT2 is transmitted to the loop unit LP11, and the power of the signal is consumed in the loop unit LP11. The power of the signal transmitted from one antenna to the other is reduced. In the antenna device 1, isolation between the antenna ANT1 and the antenna ANT2 can be secured by the loop portion LP11.

  In the antenna device 1, the resonance frequency f1 of the loop portion LP11 needs to be adjusted based on the frequency of the signal received by the antenna ANT1 or ANT2. The length of the parasitic element PE11 included in the loop portion LP11 affects the inductance component of the parasitic element PE11. When the length of the parasitic element PE11 is changed, the resonance frequency f1 of the loop portion LP11 is changed. In order to miniaturize the antenna device 1 by shortening the length of the parasitic element PE11 while securing the isolation between the antenna ANT1 and the antenna ANT2, the resonant frequency f1 of the loop portion LP11 is set to the parasitic element PE11. It needs to be adjusted in a way other than changing the length of the.

  Therefore, in the antenna device 1, the resonance frequency f1 of the loop portion LP11 is adjusted by changing the reactance of the reactance element RT11. The resonant frequency f1 of the loop portion LP11 can be adjusted by the length (inductance component) of the parasitic element PE11 and the reactance of the reactance element RT11 when the antenna device 1 is designed. Even when the parasitic element PE11 is shortened, the antenna device 1 can be designed such that the loop portion LP11 resonates with the signal received by the antenna ANT1 or ANT2 by adjusting the reactance of the reactance element RT11. As a result, the antenna device can be miniaturized.

  FIG. 2 is a view showing an example of the appearance of the antenna device 1 shown in FIG. In FIG. 2, the X-axis direction and the Y-axis direction are orthogonal to each other. The same applies to FIGS. 6, 9, and 12.

  As shown in FIG. 2, the ground conductor GND1 extends in the X-axis direction. The antenna ANT1, the parasitic element PE11 included in the loop portion LP11, and the reactance element RT11 are disposed on the dielectric substrate 10. The antenna ANT2 is disposed on the dielectric substrate 20.

  The antenna ANT1 is an inverted F-type monopole antenna which extends from the feeding point FP1 in the Y-axis direction and bends in the X-axis direction from the Y-axis direction. The antenna ANT1 includes a main body portion ML1, a short circuit line SL1, and a feed line FL1. Main body portion ML1 extends in the X-axis direction from bending portion BP1 of antenna ANT1. The feed line FL1 extends in the Y-axis direction from the feed point FP1 to the bending portion BP1. The short circuit line SL1 connects the main body portion ML1 and the ground conductor GND1. Since the short circuit line SL1 has an inductance component, the resonant frequency of the antenna ANT1 can be adjusted to a desired value by forming the short circuit line SL1.

  The mounting space can be effectively utilized by making the antenna ANT1 an inverted F-type monopole antenna. As a result, the dead space is reduced, and the antenna device 1 can be miniaturized. Further, since main body portion ML1 can be disposed apart from ground conductor GND1, capacitive coupling between main body portion ML1 and ground conductor GND1 can be weakened. As a result, the radiation capability of the signal of the main body portion ML1 can be enhanced.

  The distance between the loop portion LP11 and the antenna ANT1 is smaller than the distance between the loop portion LP11 and the antenna ANT2. Therefore, the capacitive coupling between the loop portion LP11 and the antenna ANT1 is stronger than the capacitive coupling between the loop portion LP11 and the antenna ANT2. In the first embodiment, since the loop portion LP11 is made close to the antenna ANT1, it is not necessary to form a dielectric substrate between the loop portion LP11 and the antenna ANT2. Therefore, for example, the notch of the dielectric substrate can be formed between the loop portion LP11 and the antenna ANT2, and the degree of freedom in design of the dielectric substrate can be increased.

  The parasitic element PE11 extends in the Y-axis direction from the reactance element RT11, and is bent in the X-axis direction from the Y-axis direction at the bending portion BP2. The parasitic element PE11 extends in the X-axis direction from the bending portion BP2, and is bent in the Y-axis direction from the X-axis direction at the bending portion BP3. The parasitic element PE11 extends in the Y-axis direction from the bending portion BP3 and is bent in the X-axis direction from the Y-axis direction at the bending portion BP4. The parasitic element PE11 extends in the Y-axis direction from the ground conductor GND1, and is bent in the X-axis direction from the Y-axis direction at the bending portion BP5. The parasitic element PE11 extends from the bending portion BP4 to BP5.

  Parasitic element PE11 includes portion PT1 and portion PT2. The portion PT1 is a portion from the bending portions BP2 to BP3. The portion PT2 is a portion from the bending portions BP4 to BP5. The portion PT1 is disposed between the main body portion ML1 of the antenna ANT1 and the ground conductor GND1. The distance between the portion PT2 and the ground conductor GND1 is larger than the distance between the portion PT1 and the ground conductor GND1.

  Since the parasitic element PE11 has a plurality of bending portions BP2 to BP5, the parasitic element PE11 can be arranged to be as long as possible within the limited mounting space. In addition, since the mounting space can be effectively used, the dead space can be reduced, and the antenna device 1 can be miniaturized. Furthermore, by adjusting the distance between the portion PT1 and the main body portion ML1, the capacitive coupling between the parasitic element PE11 and the antenna ANT1 can be adjusted to a desired strength.

  FIG. 3 is a diagram showing the isolation characteristic IS1 of the antenna device 1 shown in FIG. In FIG. 3, the attenuation (dB) on the vertical axis is shown as a negative value. The larger the absolute value of the amount of attenuation, the greater the isolation between the antennas, since it means that the signal received by one antenna is not transmitted to the other. The same applies to FIGS. 7 and 10. As shown in FIG. 3, the amount of attenuation is minimized at the resonance frequency f1 of the loop portion LP11, and an amount of attenuation of about -20 dB is realized.

  In the antenna device 1, the loop portion LP11 is disposed between the antennas ANT1 and ANT2. The loop portion LP11 may be disposed on the opposite side of the antenna ANT2 as viewed from the antenna ANT1 instead of between the antennas ANT1 and ANT2 as in the antenna device 1A shown in FIG. 4, for example.

  As described above, according to the antenna device according to the first embodiment and the modification of the first embodiment, the antenna device can be miniaturized while securing isolation between the antennas.

Second Embodiment
In the first embodiment, the case where only one end of the parasitic element included in the loop portion is connected to the ground conductor via the reactance element has been described. In the second embodiment, the case where the isolation between the antennas is further increased by connecting both ends of the parasitic element to the ground conductor via the reactance element will be described.

  FIG. 5 is a view showing an example of an equivalent circuit diagram of the antenna device 2 according to the second embodiment. In the antenna device 2 shown in FIG. 5, the loop portion LP11 of the antenna device 1 shown in FIG. 1 is replaced with a loop portion LP12. The configuration other than the loop portion LP12 is the same as that of the antenna device 1, and therefore the description of the configuration is not repeated.

  Loop portion LP12 includes a parasitic element PE12, and reactance elements RT11 and RT12. The end T11 of the parasitic element PE12 is connected to the ground conductor GND1 via the reactance element RT11. The end T12 of the parasitic element PE12 is connected to the ground conductor GND1 via the reactance element RT12.

  Reactance element RT12 is connected to the ground conductor at connection point N12. Reactance element RT12 includes an inductor L12. Reactance element RT12 may include a capacitor.

  In the loop portion LP12, a loop path is formed by the parasitic element PE12, the reactance element RT11, the portion of the ground conductor GND1 from the connection points N11 to N12, and the reactance element RT12. The resonance frequency of the loop portion LP12 is the resonance frequency f1 as in the first embodiment.

  FIG. 6 is a view showing an example of the appearance of the antenna device 2 shown in FIG. As shown in FIG. 6, the parasitic element PE12 and the reactance elements RT11 and RT12 included in the loop portion LP12 are disposed on the dielectric substrate 10.

  FIG. 7 is a diagram collectively showing the isolation characteristic IS2 of the antenna device 2 shown in FIG. 5 and the isolation characteristic IS1 of the antenna device 1 shown in FIG. The isolation characteristic IS1 shown in FIG. 7 is similar to the isolation characteristic IS1 shown in FIG.

  As shown in FIG. 7, at the resonance frequency f1 of the loop portion LP12, the absolute value of the attenuation of the isolation characteristic IS2 exceeds the absolute value of the attenuation of the isolation characteristic IS1 by about 15 dB. Thus, both ends of the parasitic element PE12 are connected to the ground conductor via the reactance elements RT11 and RT12, respectively, when the absolute value of the attenuation of the isolation characteristic IS2 exceeds the absolute value of the attenuation of the isolation characteristic IS1. This is because the bias of the current distribution in the parasitic element PE12 is suppressed more than in the first embodiment. According to the antenna device 2, the isolation between the antennas ANT1 and ANT2 can be further increased.

  As described above, also with the antenna device according to the second embodiment, isolation between the antennas can be ensured, and the antenna device can be miniaturized.

  Furthermore, according to the antenna device of the second embodiment, both ends of the parasitic element in the loop portion are connected to the ground conductor through the reactance element, respectively, to suppress the bias of the current distribution in the parasitic element. Can. As a result, isolation between antennas can be further increased.

Third Embodiment
In Embodiment 1 and Embodiment 2, the case where the antenna device includes one loop portion has been described. The antenna device according to the present invention may include a plurality of loop portions. In the third embodiment, the case where the antenna apparatus includes two loop units and the loop unit is disposed for each antenna will be described.

  FIG. 8 is a diagram showing an example of an equivalent circuit diagram of the antenna device 3 according to the third embodiment. In the antenna device 3 shown in FIG. 8, a loop portion LP22 is added to the configuration of the antenna device 2 shown in FIG. The configuration other than the loop portion LP22 is the same as that of the antenna device 2, and therefore the description of the configuration is not repeated.

  Loop portion LP22 includes a parasitic element PE22, and reactance elements RT21 and RT22. The end T21 of the parasitic element PE22 is connected to the ground conductor GND1 via the reactance element RT21. The end T22 of the parasitic element PE22 is connected to the ground conductor GND1 via the reactance element RT22.

  Reactance element RT21 is connected to ground conductor GND1 at connection point N21. Reactance element RT21 includes an inductor L21. Reactance element RT21 may include a capacitor.

  Reactance element RT22 is connected to ground conductor GND1 at connection point N22. Reactance element RT22 includes an inductor L22. Reactance element RT22 may include a capacitor.

  In the loop portion LP22, a loop path is formed by the parasitic element PE22, the reactance element RT21, the portion of the ground conductor GND1 from the connection points N21 to N22, and the reactance element RT22. The resonant frequency of the loop portion LP22 is a resonant frequency f2.

  The capacitive coupling between the loop portion LP22 and the antenna ANT2 is stronger than the capacitive coupling between the loop portion LP22 and the antenna ANT1. The magnitude relationship in FIG. 8 is expressed by the parasitic element PE22 and the antenna ANT2 being connected via the capacitor C2, while the parasitic element PE22 and the antenna ANT1 are not connected via the capacitor. ing.

  FIG. 9 is a view showing an example of the appearance of the antenna device 3 shown in FIG. As shown in FIG. 9, the parasitic element PE21 and the reactance elements RT21 and RT22 included in the loop portion LP22 are disposed on the dielectric substrate 20.

  The distance between the loop portion LP22 and the antenna ANT2 is smaller than the distance between the loop portion LP22 and the antenna ANT1. Therefore, the capacitive coupling between the loop portion LP22 and the antenna ANT2 is stronger than the capacitive coupling between the loop portion LP22 and the antenna ANT1. In the second embodiment, since the loop portion LP22 is close to the antenna ANT2, it is not necessary to form a dielectric substrate between the loop portion LP22 and the antenna ANT1. Therefore, for example, the notch of the dielectric substrate can be formed between the loop portion LP22 and the antenna ANT1, and the degree of freedom in design of the dielectric substrate can be increased.

  FIG. 10 is a diagram showing together the isolation characteristic IS3 of the antenna device 3 shown in FIG. 8 and the isolation characteristic IS2 of the antenna device 2 shown in FIG. The isolation characteristic IS2 shown in FIG. 10 is similar to the isolation characteristic IS2 shown in FIG. In the frequency band of 2000 to 3000 MHz shown in FIG. 10, the isolation characteristic IS3 has a larger absolute value of attenuation than the isolation characteristic IS2. The isolation characteristic IS3 has the largest absolute value of the amount of attenuation at the resonance frequency f2 of the loop portion LP22.

  Since the antenna device 3 includes the two loop parts LP12 and LP22, when the signal received by the antenna ANT1 or ANT2 is transmitted to the loop part LP12, the energy of the signal is consumed in the loop part LP12. The energy of the signal is consumed in the loop portion LP22 also when it is transmitted to the loop portion LP22. As a result, the absolute value of attenuation is larger in the isolation characteristic IS3 than in the isolation characteristic IS2, and the isolation between the antennas ANT1 and ANT2 can be further increased.

  As described above, also with the antenna device according to the third embodiment, isolation between the antennas can be ensured, and the antenna device can be miniaturized.

  Furthermore, according to the antenna device according to the third embodiment, the isolation between the antennas can be further increased by the plurality of loop portions.

Fourth Embodiment
In Embodiments 1 to 3, the case where the antenna device includes two antennas has been described. The antenna device according to the present invention may include three or more antennas. In the fourth embodiment, the case in which the antenna apparatus includes three antennas will be described.

  FIG. 11 is a diagram showing an example of an equivalent circuit diagram of the antenna device 4 according to the fourth embodiment. In the antenna device 4 shown in FIG. 11, an antenna ANT3, a loop portion LP32, and a feeding point FP3 are added to the configuration of the antenna device 3 shown in FIG. The configuration other than these is the same as that of the antenna device 3, and therefore the description of the configuration is not repeated.

  The antenna ANT3 is connected to the ground conductor GND1 via the feeding point FP3. Loop portion LP32 includes a parasitic element PE32, and reactance elements RT31 and RT32. The end T31 of the parasitic element PE32 is connected to the ground conductor GND1 via the reactance element RT31. The end T32 of the parasitic element PE32 is connected to the ground conductor GND1 via the reactance element RT32.

  Reactance element RT31 is connected to ground conductor GND1 at connection point N31. Reactance element RT31 includes an inductor L31. Reactance element RT31 may include a capacitor.

  Reactance element RT32 is connected to ground conductor GND1 at connection point N32. Reactance element RT32 includes an inductor L32. Reactance element RT32 may include a capacitor.

  In the loop portion LP32, a loop path is formed by the parasitic element PE32, the reactance element RT31, the portion of the ground conductor GND1 from the connection points N31 to N32, and the reactance element RT32.

  The capacitive coupling between the loop portion LP32 and the antenna ANT3 is stronger than the capacitive coupling between the loop portion LP32 and the antenna ANT1, and is stronger than the capacitive coupling between the loop portion LP32 and the antenna ANT2. The magnitude relationship in FIG. 11 is that the parasitic element PE32 and the antenna ANT3 are connected via the capacitor C3, while the parasitic element PE32 and the antennas ANT1 and ANT2 are not connected via the capacitor. It is expressed.

  FIG. 12 is a view showing an example of the appearance of the antenna device 4 shown in FIG. As shown in FIG. 12, the antenna ANT 3, the parasitic element PE 32 included in the loop portion LP 32, and the reactance elements RT 31 and RT 32 are disposed on the dielectric substrate 30.

  The distance between the loop portion LP32 and the antenna ANT3 is smaller than the distance between the loop portion LP32 and the antenna ANT1, and smaller than the distance between the loop portion LP32 and the antenna ANT2. Therefore, the capacitive coupling between the loop portion LP32 and the antenna ANT3 is stronger than the capacitive coupling between the loop portion LP32 and the antenna ANT1, and stronger than the capacitive coupling between the loop portion LP32 and the antenna ANT2. In the fourth embodiment, it is not necessary to form a dielectric substrate between the loop portion LP32 and the antenna ANT1 and between the loop portion LP32 and the antenna ANT2 by bringing the loop portion LP32 close to the antenna ANT3. Therefore, for example, a notch of the dielectric substrate can be formed between the loop portion LP32 and the antenna ANT1 and between the loop portion LP32 and the antenna ANT2 to increase the degree of freedom in design of the dielectric substrate.

  In the fourth embodiment, the case where the loop portion is arranged for every three antennas has been described. It is not necessary to arrange a loop portion for every three antennas, and if there is only one loop portion in which at least one end of the parasitic element is connected to the ground conductor via a reactance element, what kind of configuration It may be. For example, antenna apparatus 4A (when there is no loop portion corresponding to antenna ANT2) according to the first modification of the fourth embodiment shown in FIG. 13 and antenna apparatus 4B according to the second modification of the fourth embodiment shown in FIG. As in the case where there is no loop portion corresponding to the antenna ANT3, the configuration may be such that there is no loop portion corresponding to one of the three antennas. Alternatively, as in an antenna apparatus 4C (in the case where there is no loop portion corresponding to antenna ANT2 and antenna ANT3) according to the third modification of the fourth embodiment shown in FIG. It may be a configuration without a corresponding loop part.

  As described above, also with the antenna devices according to the fourth embodiment and the first to third modifications of the fourth embodiment, isolation between the antennas can be secured and the antenna device can be miniaturized.

  The embodiments disclosed herein are also planned to be implemented in combination as appropriate, as long as no contradiction arises. It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is shown not by the above description but by the scope of claims, and is intended to include all modifications within the scope and meaning equivalent to the scope of claims.

  1 to 4, 1A, 4A to 4C antenna device, 10, 20, 30 dielectric substrate, ANT1 to ANT3 antenna, BP1 to BP5 bent portion, C1 to C3 capacitor, FL1 feeder, FP1 to FP3 feeding point, GND1 ground conductor L11, L12, L21, L22, L31, L32 Inductor, LP11, LP12, LP22, LP32 Loop part, ML1 body part, PE1, PE11, PE12, PE21, PE22, PE32 Parasitic element, PT1, PT2 part, RT11, RT12, RT21, RT22, RT31, RT32 Reactive element, SL1 short circuit.

Claims (14)

With a ground conductor,
A first antenna and a second antenna electrically connected to the ground conductor;
A first loop portion including a first parasitic element and a first reactance element;
In the first parasitic element, one end of the first parasitic element is electrically connected to the ground conductor, and the other end of the first parasitic element is the first reactive element via the first reactance element. An antenna device connected to a ground conductor.   The antenna device according to claim 1, wherein a distance between the first loop portion and the first antenna is smaller than a distance between the first loop portion and the second antenna.   The antenna device according to claim 2, wherein the first loop portion is close to the first antenna.   The antenna device according to any one of claims 1 to 3, wherein the first reactance element has an inductor. The ground conductor extends in a first direction,
The said 1st parasitic element is extended in the 2nd direction orthogonal to the said 1st direction, and has a bending part bent in the said 1st direction from the said 2nd direction. The antenna device according to item 1.   The antenna device according to claim 5, wherein the first antenna is a monopole antenna bent in the first direction from the second direction. The first parasitic element includes a first portion and a second portion along the first direction,
The first portion is disposed between a specific portion along the first direction of the first antenna and the ground conductor.
The antenna device according to claim 6, wherein a distance between the second portion and the ground conductor is larger than a distance between the first portion and the ground conductor.   The antenna device according to claim 7, further comprising a shorting conductor connecting the specific portion to the ground conductor. The first loop unit further includes a second reactance element,
The antenna device according to any one of claims 1 to 8, wherein the one end of the first parasitic element is connected to the ground conductor via the second reactance element. It further comprises a second loop section,
The antenna device according to any one of claims 1 to 9, wherein a distance between the second loop portion and the second antenna is smaller than a distance between the second loop portion and the first antenna.   The antenna device according to claim 10, wherein the second loop portion is close to the second antenna. And a third antenna electrically connected to the ground conductor,
The distance between the first loop portion and the first antenna is smaller than the distance between the first loop portion and the third antenna,
The antenna device according to claim 10, wherein a distance between the second loop portion and the second antenna is smaller than a distance between the second loop portion and the third antenna. It further comprises a third loop section,
The distance between the third loop portion and the third antenna is smaller than the distance between the third loop portion and the first antenna, and smaller than the distance between the third loop portion and the second antenna. An antenna device according to Item 12.   The antenna device according to claim 13, wherein the third loop portion is close to the third antenna.

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