WO2018123345A1 - Antenna device - Google Patents

Antenna device Download PDF

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Publication number
WO2018123345A1
WO2018123345A1 PCT/JP2017/041650 JP2017041650W WO2018123345A1 WO 2018123345 A1 WO2018123345 A1 WO 2018123345A1 JP 2017041650 W JP2017041650 W JP 2017041650W WO 2018123345 A1 WO2018123345 A1 WO 2018123345A1
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WIPO (PCT)
Prior art keywords
antenna
antenna device
loop
ground conductor
loop portion
Prior art date
Application number
PCT/JP2017/041650
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French (fr)
Japanese (ja)
Inventor
正裕 伊澤
Original Assignee
株式会社村田製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社村田製作所 filed Critical 株式会社村田製作所
Priority to CN201780080840.5A priority Critical patent/CN110121815B/en
Priority to JP2018558901A priority patent/JP6673503B2/en
Publication of WO2018123345A1 publication Critical patent/WO2018123345A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/52—Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/28—Combinations of substantially independent non-interacting antenna units or systems
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/30—Resonant antennas with feed to end of elongated active element, e.g. unipole
    • H01Q9/42—Resonant antennas with feed to end of elongated active element, e.g. unipole with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Definitions

  • the present invention relates to an antenna device including a plurality of antennas.
  • Patent Document 1 Japanese Unexamined Patent Application Publication No. 2006-42111 discloses an antenna device including two antennas.
  • Isolation is an amount indicating the degree of signal leakage from one antenna element to the other antenna element between antenna elements. Isolation is expressed as the ratio (dB) between the power of the input signal to one antenna element and the power of the leakage signal from one antenna element to the other antenna element.
  • the current excited from one antenna to the other is reduced by a resonance phenomenon that occurs in the loop path formed by the parasitic element and the ground plane. As a result, isolation between antennas is ensured.
  • the resonance 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. If the length of the parasitic element is changed, the resonance frequency of the loop path changes. For this reason, if the length of the parasitic element is changed, the loop portion hardly resonates with the signal received by the antenna. There is a possibility that the amount of signal transmitted from the antenna to the other antenna increases and the isolation between the antennas decreases.
  • the parasitic element can be an obstacle to downsizing the antenna device while ensuring isolation between the antennas.
  • the present invention has been made to solve the above-described problems, and an object of the present invention is to downsize the antenna device while ensuring isolation between the antennas.
  • An antenna device 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 unit 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.
  • a circuit element is "electrically connected" to another circuit element when both are directly connected or indirectly connected via a different circuit element. Means.
  • the antenna device when the signal received by the first antenna or the second antenna is transmitted to the first loop unit, the energy of the signal is consumed in the first loop unit. The power of the signal transmitted from one antenna to the other antenna is reduced. As a result, isolation between antennas can be ensured.
  • the other end of the first parasitic element is connected to the ground conductor via the first reactance element.
  • the resonance frequency of the first loop portion can be adjusted by the length of the first parasitic element (inductance component) 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 so that the first loop unit 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 reduced in size.
  • the antenna device according to the present invention can reduce the size of the antenna device while ensuring isolation between the antennas.
  • FIG. 3 is a diagram illustrating an example of an equivalent circuit diagram of the antenna device according to Embodiment 1.
  • FIG. It is a figure which shows an example of the external appearance of the antenna apparatus shown by FIG.
  • FIG. 6 is a diagram showing an example of an equivalent circuit diagram of an antenna device according to a modification of the first embodiment.
  • FIG. 6 is a diagram illustrating an example of an equivalent circuit diagram of an antenna device according to Embodiment 2.
  • FIG. 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. 5, and the isolation characteristic of the antenna apparatus shown by FIG.
  • FIG. 10 is a diagram illustrating an example of an equivalent circuit diagram of the antenna device according to the third embodiment. 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 together the isolation characteristic of the antenna apparatus shown by FIG. 8, and the isolation characteristic of the antenna apparatus shown by FIG.
  • FIG. 10 is a diagram illustrating an example of an equivalent circuit diagram of an antenna device according to a fourth embodiment. It is a figure which shows an example of the external appearance of the antenna apparatus shown by FIG.
  • FIG. 10 is a diagram illustrating an example of an equivalent circuit diagram of an antenna device according to Modification 1 of Embodiment 4.
  • FIG. 10 is a diagram showing an example of an equivalent circuit diagram of an antenna device according to Modification 2 of Embodiment 4.
  • FIG. 10 is a diagram illustrating an example of an equivalent circuit diagram of an antenna device according to Modification 3 of Embodiment 4.
  • FIG. 1 is a diagram illustrating an example of an equivalent circuit diagram of the antenna device 1 according to the first embodiment.
  • the antenna device 1 can perform communication according to a plurality of communication methods.
  • the antenna device 1 can perform communication in accordance with WiFi (registered trademark) (Wireless Fidelity) and Bluetooth (registered trademark) in, for example, 2400 to 2484 MHz (2.4 GHz band).
  • WiFi registered trademark
  • Bluetooth registered trademark
  • the antenna device 1 includes a ground conductor GND1, antennas ANT1 and ANT2, and a loop portion LP11.
  • the ground conductor GND ⁇ b> 1 is drawn as a straight line connecting the feeding points FP ⁇ b> 1 and FP ⁇ b> 2 in order to make it easy to understand the connection relationship between each component. The same applies to FIG. 4, FIG. 5, FIG. 8, FIG. 11, and FIG.
  • the antenna ANT1 is connected to the ground conductor GND1 through the feeding point FP1.
  • the antenna ANT2 is connected to the ground conductor GND1 through the feeding point FP2.
  • the resonance frequency of the antenna ANT1 is close to the resonance frequency of the antenna ANT2.
  • the 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.
  • the reactance element RT11 is connected to the ground conductor GND1 at the connection point N11.
  • the reactance element RT11 includes an inductor L11.
  • the reactance element RT11 may include a capacitor.
  • 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 part LP11 and the antenna ANT1 is stronger than the capacitive coupling between the loop part LP11 and the antenna ANT2.
  • the magnitude relationship is expressed by the fact 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.
  • the antenna device 1 including the antennas ANT1 and ANT2, it is necessary to ensure isolation between the antennas ANT1 and ANT2.
  • the signal received by the antenna ANT1 or ANT2 is transmitted to the loop part LP11, whereby the power of the signal is consumed in the loop part LP11.
  • the power of the signal transmitted from one antenna to the other antenna is reduced.
  • the isolation between the antenna ANT1 and the antenna ANT2 can be ensured by the loop portion LP11.
  • 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.
  • the resonance frequency f1 of the loop portion LP11 is changed.
  • the resonance frequency f1 of the loop portion LP11 is set to the parasitic element PE11. It is necessary to adjust by a method other than the change of the length.
  • the resonance frequency f1 of the loop portion LP11 is adjusted by changing the reactance of the reactance element RT11.
  • the resonance 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 so that the loop portion LP11 resonates with a 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 reduced in size.
  • FIG. 2 is a diagram 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 FIG. 6, FIG. 9, and FIG.
  • the ground conductor GND1 extends in the X-axis direction.
  • the antenna ANT1, the parasitic element PE11 included in the loop part LP11, and the reactance element RT11 are arranged 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 that extends from the feed point FP1 in the Y-axis direction and bends from the Y-axis direction to the X-axis direction.
  • the antenna ANT1 includes a main body ML1, a short-circuit line SL1, and a feed line FL1.
  • the main body ML1 extends in the X-axis direction from the bent portion BP1 of the antenna ANT1.
  • the feed line FL1 extends in the Y-axis direction from the feed point FP1 to the bent portion BP1.
  • the short-circuit line SL1 connects the main body ML1 and the ground conductor GND1. Since the short circuit line SL1 has an inductance component, the resonance 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 monopole antenna. As a result, the dead space is reduced and the antenna device 1 can be downsized. Further, since the main body ML1 can be arranged away from the ground conductor GND1, the capacitive coupling between the main body ML1 and the ground conductor GND1 can be weakened. As a result, the signal radiation capability of the main body ML1 can be increased.
  • the distance between the loop part LP11 and the antenna ANT1 is smaller than the distance between the loop part LP11 and the antenna ANT2. Therefore, capacitive coupling between the loop part LP11 and the antenna ANT1 is stronger than capacitive coupling between the loop part LP11 and the antenna ANT2.
  • the loop portion LP11 since the loop portion LP11 is 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, a notch (notch) of the dielectric substrate can be formed between the loop portion LP11 and the antenna ANT2, and the degree of freedom in designing 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 bent portion BP2 from the Y-axis direction to the X-axis direction.
  • the parasitic element PE11 extends from the bent portion BP2 in the X-axis direction, and is bent from the X-axis direction to the Y-axis direction at the bent portion BP3.
  • the parasitic element PE11 extends from the bent portion BP3 in the Y-axis direction, and is bent in the bent portion BP4 from the Y-axis direction to the X-axis direction.
  • the parasitic element PE11 extends from the ground conductor GND1 in the Y-axis direction, and is bent from the Y-axis direction to the X-axis direction at the bent portion BP5.
  • the parasitic element PE11 extends from the bent part BP4 to BP5.
  • the parasitic element PE11 includes a part PT1 and a part PT2.
  • the part PT1 is a part from the bent parts BP2 to BP3.
  • the part PT2 is a part from the bent parts BP4 to BP5.
  • the part PT1 is disposed between the main body 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.
  • the parasitic element PE11 has a plurality of bent portions BP2 to BP5, the parasitic element PE11 can be arranged to be as long as possible in a limited mounting space. Further, since the mounting space can be used effectively, the dead space is reduced and the antenna device 1 can be downsized. Furthermore, by adjusting the distance between the portion PT1 and the main body 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.
  • the vertical axis attenuation (dB) is shown as a negative value.
  • FIGS. 7 and 10. As shown in FIG. 3, the attenuation is minimized at the resonance frequency f1 of the loop portion LP11, and an attenuation of about ⁇ 20 dB is realized.
  • the loop portion LP11 is disposed between the antennas ANT1 and ANT2.
  • the loop portion LP11 may be disposed not on the antenna ANT1 and ANT2, but on the side opposite to the antenna ANT2, as seen from the antenna ANT1, as in the antenna device 1A shown in FIG.
  • the antenna device can be downsized while ensuring the isolation between the antennas.
  • FIG. 5 is a diagram illustrating an example of an equivalent circuit diagram of the antenna device 2 according to the second embodiment.
  • the loop portion LP11 of the antenna device 1 shown in FIG. 1 is replaced with a loop portion LP12. Since the configuration other than the loop portion LP12 is the same as that of the antenna device 1, the description of the configuration will not be repeated.
  • the 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.
  • the reactance element RT12 is connected to the ground conductor at the connection point N12.
  • the reactance element RT12 includes an inductor L12.
  • the reactance element RT12 may include a capacitor.
  • 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 diagram 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 arranged on the dielectric substrate 10.
  • FIG. 7 is a diagram 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 the same as the isolation characteristic IS1 shown in FIG.
  • the absolute value of the attenuation amount of the isolation characteristic IS2 exceeds the absolute value of the attenuation amount of the isolation characteristic IS1 by about 15 dB.
  • the absolute value of the attenuation amount of the isolation characteristic IS2 exceeds the absolute value of the attenuation amount of the isolation characteristic IS1 because both ends of the parasitic element PE12 are connected to the ground conductor via the reactance elements RT11 and RT12, respectively. This is because the bias of the current distribution in the parasitic element PE12 is suppressed more than in the first embodiment.
  • the isolation between the antennas ANT1 and ANT2 can be further increased.
  • both ends of the parasitic element of the loop portion are connected to the ground conductor via the reactance elements, respectively, thereby suppressing the bias of the current distribution in the parasitic element. Can do. As a result, the isolation between the antennas can be further increased.
  • the antenna device includes one loop unit.
  • the antenna device according to the present invention may include a plurality of loop portions.
  • the antenna device includes two loop units, and the loop unit is arranged for each antenna.
  • FIG. 8 is a diagram illustrating an example of an equivalent circuit diagram of the antenna device 3 according to the third embodiment.
  • a loop portion LP22 is added to the configuration of the antenna device 2 shown in FIG. Since the configuration other than the loop portion LP22 is the same as that of the antenna device 2, the description of the configuration will not be repeated.
  • the 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.
  • the reactance element RT21 is connected to the ground conductor GND1 at the connection point N21.
  • the reactance element RT21 includes an inductor L21.
  • the reactance element RT21 may include a capacitor.
  • the reactance element RT22 is connected to the ground conductor GND1 at the connection point N22.
  • the reactance element RT22 includes an inductor L22.
  • the reactance element RT22 may include a capacitor.
  • 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 resonance frequency of the loop portion LP22 is the resonance frequency f2.
  • the capacitive coupling between the loop part LP22 and the antenna ANT2 is stronger than the capacitive coupling between the loop part LP22 and the antenna ANT1.
  • the magnitude relationship is expressed by the fact that the parasitic element PE22 and the antenna ANT2 are 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 diagram 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 arranged on the dielectric substrate 20.
  • the distance between the loop part LP22 and the antenna ANT2 is smaller than the distance between the loop part LP22 and the antenna ANT1. Therefore, capacitive coupling between the loop part LP22 and the antenna ANT2 is stronger than capacitive coupling between the loop part LP22 and the antenna ANT1.
  • the loop part LP22 since the loop part LP22 is close to the antenna ANT2, it is not necessary to form a dielectric substrate between the loop part LP22 and the antenna ANT1. Therefore, for example, a notch of the dielectric substrate can be formed between the loop portion LP22 and the antenna ANT1, and the degree of freedom in designing the dielectric substrate can be increased.
  • FIG. 10 is a diagram showing 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 the same as 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 attenuation at the resonance frequency f2 of the loop portion LP22.
  • the antenna device 3 since the antenna device 3 includes two loop portions LP12 and LP22, when the signal received by the antenna ANT1 or ANT2 is transmitted to the loop portion LP12, the energy of the signal is consumed in the loop portion LP12. Even when the signal is transmitted to the loop part LP22, the energy of the signal is consumed in the loop part LP22. As a result, the isolation characteristic IS3 has a greater attenuation value than the isolation characteristic IS2, and the isolation between the antennas ANT1 and ANT2 can be further increased.
  • the isolation between the antennas can be further increased by the plurality of loop portions.
  • 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.
  • the case where the antenna device includes three antennas will be described.
  • FIG. 11 is a diagram illustrating an example of an equivalent circuit diagram of the antenna device 4 according to the fourth embodiment.
  • an antenna ANT3, a loop portion LP32, and a feed point FP3 are added to the configuration of the antenna device 3 shown in FIG. Since the configuration other than these is the same as that of the antenna device 3, the description of the configuration will not be repeated.
  • 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.
  • the reactance element RT31 is connected to the ground conductor GND1 at the connection point N31.
  • the reactance element RT31 includes an inductor L31.
  • the reactance element RT31 may include a capacitor.
  • the reactance element RT32 is connected to the ground conductor GND1 at the connection point N32.
  • the reactance element RT32 includes an inductor L32.
  • the reactance element RT32 may include a capacitor.
  • 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 part LP32 and the antenna ANT3 is stronger than the capacitive coupling between the loop part LP32 and the antenna ANT1, and is stronger than the capacitive coupling between the loop part LP32 and the antenna ANT2.
  • the magnitude relationship 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 diagram showing an example of the appearance of the antenna device 4 shown in FIG. As shown in FIG. 12, the antenna ANT3, the parasitic element PE32 included in the loop part LP32, and the reactance elements RT31 and RT32 are arranged on the dielectric substrate 30.
  • the distance between the loop part LP32 and the antenna ANT3 is smaller than the distance between the loop part LP32 and the antenna ANT1, and smaller than the distance between the loop part LP32 and the antenna ANT2. Therefore, capacitive coupling between the loop part LP32 and the antenna ANT3 is stronger than capacitive coupling between the loop part LP32 and the antenna ANT1, and stronger than capacitive coupling between the loop part LP32 and the antenna ANT2.
  • Embodiment 4 the case where a loop part is arranged for every three antennas has been described. There is no need for a loop portion to be arranged for every three antennas, and if there is one loop portion in which at least one end of a parasitic element is connected to a ground conductor via a reactance element, any configuration is possible. There may be.
  • antenna device 4A according to Modification 1 of Embodiment 4 shown in FIG. 13 when there is no loop portion corresponding to antenna ANT2
  • antenna device 4B according to Modification 2 of Embodiment 4 shown in FIG.
  • the configuration may be such that there is no loop portion corresponding to one of the three antennas, as in the case where there is no loop portion corresponding to the antenna ANT3.
  • two antennas out of the three antennas are used as in the antenna device 4C according to the third modification of the fourth embodiment shown in FIG. 15 (when there is no loop portion corresponding to the antenna ANT2 and the antenna ANT3).
  • a configuration without a corresponding loop portion may be used.
  • the antenna devices according to the fourth and fourth modification examples 1 to 3 of the fourth embodiment can secure the isolation between the antennas and reduce the size of the antenna device.

Abstract

The purpose of the present invention is to reduce the size of an antenna device while ensuring isolation between antennas. An antenna device (1) according to one embodiment of the present invention comprises: a ground conductor (GND1); a first antenna (ANT1); a second antenna (ANT2); and a loop part (LP11). The first antenna (ANT1) and the second antenna (ANT2) are electrically connected to the ground conductor. The loop part (LP11) includes a parasitic element (PE11) and a reactance element (RT11). For the parasitic element (PE11), an end part (T10) is electrically connected to the ground conductor (GND1). For the parasitic element (PE11) an end part (T9) is connected to the ground conductor (GND1) via the reactance element (RT11).

Description

アンテナ装置Antenna device
　本発明は、複数のアンテナを備えるアンテナ装置に関する。 The present invention relates to an antenna device including a plurality of antennas.
　複数のアンテナを備えるアンテナ装置が知られている。たとえば、特開２００６－４２１１１号公報（特許文献１）には、２つのアンテナを備えるアンテナ装置が開示されている。 An antenna device having a plurality of antennas is known. For example, Japanese Unexamined Patent Application Publication No. 2006-42111 (Patent Document 1) discloses an antenna device including two antennas.
特開２００６－４２１１１号公報JP 2006-42111 A
　複数のアンテナを備えるアンテナ装置においては、アンテナ間のアイソレーションを確保する必要がある。アイソレーションとは、アンテナ素子間において一方のアンテナ素子から他方のアンテナ素子への信号の漏れの程度を示す量である。アイソレーションは、一方のアンテナ素子への入力信号の電力と、一方のアンテナ素子から他方のアンテナ素子への漏洩信号の電力との比（ｄＢ）として表される。 In an antenna apparatus having a plurality of antennas, it is necessary to ensure isolation between the antennas. Isolation is an amount indicating the degree of signal leakage from one antenna element to the other antenna element between antenna elements. Isolation is expressed as the ratio (dB) between the power of the input signal to one antenna element and the power of the leakage signal from one antenna element to the other antenna element.
　特許文献１に開示されているアンテナ装置においては、無給電素子および地板によって形成されたループ経路において生じる共振現象により、一方のアンテナから他方のアンテナへ励振される電流が低減される。その結果、アンテナ間のアイソレーションが確保される。 In the antenna device disclosed in Patent Document 1, the current excited from one antenna to the other is reduced by a resonance phenomenon that occurs in the loop path formed by the parasitic element and the ground plane. As a result, isolation between antennas is ensured.
　特許文献１に開示されているようなアンテナ装置において、ループ経路の共振周波数は、アンテナが受信する信号の周波数に基づいて調整される必要がある。無給電素子の長さは、無給電素子のインダクタンス成分に影響を与える。無給電素子の長さを変更すると、ループ経路の共振周波数が変わってしまう。そのため、無給電素子の長さを変更するとアンテナによって受信された信号にループ部が共振し難くなる。当該アンテナから他方のアンテナに伝達される信号量が増加しアンテナ間のアイソレーションが低下する可能性がある。特許文献１に開示されているようなアンテナ装置においては、無給電素子が、アンテナ間のアイソレーションを確保しながらアンテナ装置を小型化することの障害になり得る。 In the antenna device as disclosed in Patent Document 1, the resonance 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. If the length of the parasitic element is changed, the resonance frequency of the loop path changes. For this reason, if the length of the parasitic element is changed, the loop portion hardly resonates with the signal received by the antenna. There is a possibility that the amount of signal transmitted from the antenna to the other antenna increases and the isolation between the antennas decreases. In the antenna device disclosed in Patent Document 1, the parasitic element can be an obstacle to downsizing the antenna device while ensuring isolation between the antennas.
　本発明は上記のような課題を解決するためになされたものであり、その目的はアンテナ間のアイソレーションを確保しながら、アンテナ装置を小型化することである。 The present invention has been made to solve the above-described problems, and an object of the present invention is to downsize the antenna device while ensuring isolation between the antennas.
　本発明の一実施形態に係るアンテナ装置は、グランド導体と、第１アンテナおよび第２アンテナと、第１ループ部とを備える。第１アンテナおよび第２アンテナは、グランド導体に電気的に接続されている。第１ループ部は、第１無給電素子と第１リアクタンス素子とを含む。第１無給電素子は、第１無給電素子の一方端がグランド導体に電気的に接続されている。第１無給電素子は、第１無給電素子の他方端が第１リアクタンス素子を介してグランド導体に接続されている。 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 unit 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.
　或る回路素子が他の回路素子に「電気的に接続されている」とは、両者が直接に接続されていること、あるいは両者とは別の回路素子を介して間接に接続されていることを意味する。 A circuit element is "electrically connected" to another circuit element when both are directly connected or indirectly connected via a different circuit element. Means.
　本発明に係るアンテナ装置においては、第１アンテナあるいは第２アンテナによって受信された信号が第１ループ部に伝達されることにより、当該信号のエネルギーが第１ループ部において消費される。一方のアンテナから他方のアンテナへ伝達される信号の電力が低減される。その結果、アンテナ間のアイソレーションを確保することができる。 In the antenna device according to the present invention, when the signal received by the first antenna or the second antenna is transmitted to the first loop unit, the energy of the signal is consumed in the first loop unit. The power of the signal transmitted from one antenna to the other antenna is reduced. As a result, isolation between antennas can be ensured.
　また、本発明に係るアンテナ装置においては、第１無給電素子の他方端が第１リアクタンス素子を介してグランド導体に接続されている。第１ループ部の共振周波数は、アンテナ装置の設計時において、第１無給電素子の長さ（インダクタンス成分）および第１リアクタンス素子のリアクタンスによって調整可能である。第１無給電素子を短くする場合でも、第１リアクタンス素子のリアクタンスを調整することにより、第１ループ部が第１アンテナによって受信された信号に共振するようにアンテナ装置を設計することができる。その結果、アンテナ装置を小型化することができる。 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 resonance frequency of the first loop portion can be adjusted by the length of the first parasitic element (inductance component) 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 so that the first loop unit 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 reduced in size.
　本発明に係るアンテナ装置によれば、アンテナ間のアイソレーションを確保しながら、アンテナ装置を小型化することができる。 The antenna device according to the present invention can reduce the size of the antenna device while ensuring isolation between the antennas.
実施の形態１に係るアンテナ装置の等価回路図の一例を示す図である。3 is a diagram illustrating an example of an equivalent circuit diagram of the antenna device according to Embodiment 1. FIG. 図１に示されるアンテナ装置の外観の一例を示す図である。It is a figure which shows an example of the external appearance of the antenna apparatus shown by FIG. 図１に示されるアンテナ装置のアイソレーション特性を示す図である。It is a figure which shows the isolation characteristic of the antenna apparatus shown by FIG. 実施の形態１の変形例に係るアンテナ装置の等価回路図の一例を示す図である。6 is a diagram showing an example of an equivalent circuit diagram of an antenna device according to a modification of the first embodiment. FIG. 実施の形態２に係るアンテナ装置の等価回路図の一例を示す図である。6 is a diagram illustrating an example of an equivalent circuit diagram of an antenna device according to Embodiment 2. FIG. 図５に示されるアンテナ装置の外観の一例を示す図である。It is a figure which shows an example of the external appearance of the antenna apparatus shown by FIG. 図５に示されるアンテナ装置のアイソレーション特性、および図１に示されるアンテナ装置のアイソレーション特性を併せて示す図である。It is a figure which shows the isolation characteristic of the antenna apparatus shown by FIG. 5, and the isolation characteristic of the antenna apparatus shown by FIG. 実施の形態３に係るアンテナ装置の等価回路図の一例を示す図である。FIG. 10 is a diagram illustrating an example of an equivalent circuit diagram of the antenna device according to the third embodiment. 図８に示されるアンテナ装置の外観の一例を示す図である。It is a figure which shows an example of the external appearance of the antenna apparatus shown by FIG. 図８に示されるアンテナ装置のアイソレーション特性、および図５に示されるアンテナ装置のアイソレーション特性を併せて示す図である。It is a figure which shows together the isolation characteristic of the antenna apparatus shown by FIG. 8, and the isolation characteristic of the antenna apparatus shown by FIG. 実施の形態４に係るアンテナ装置の等価回路図の一例を示す図である。FIG. 10 is a diagram illustrating an example of an equivalent circuit diagram of an antenna device according to a fourth embodiment. 図１１に示されるアンテナ装置の外観の一例を示す図である。It is a figure which shows an example of the external appearance of the antenna apparatus shown by FIG. 実施の形態４の変形例１に係るアンテナ装置の等価回路図の一例を示す図である。FIG. 10 is a diagram illustrating an example of an equivalent circuit diagram of an antenna device according to Modification 1 of Embodiment 4. 実施の形態４の変形例２に係るアンテナ装置の等価回路図の一例を示す図である。FIG. 10 is a diagram showing an example of an equivalent circuit diagram of an antenna device according to Modification 2 of Embodiment 4. 実施の形態４の変形例３に係るアンテナ装置の等価回路図の一例を示す図である。FIG. 10 is a diagram illustrating an example of an equivalent circuit diagram of an antenna device according to Modification 3 of Embodiment 4.
　以下、本発明の実施の形態について、図面を参照しながら詳細に説明する。なお、図中同一または相当部分には同一符号を付してその説明は原則として繰り返さない。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated in principle.
　［実施の形態１］
　図１は、実施の形態１に係るアンテナ装置１の等価回路図の一例を示す図である。アンテナ装置１は、複数の通信方式に準拠して通信を行なうことができる。アンテナ装置１は、たとえば２４００～２４８４ＭＨｚ（２．４ＧＨｚ帯）においてＷｉＦｉ（登録商標）（Wireless　Fidelity）およびＢｌｕｅｔｏｏｔｈ（登録商標）に準拠して通信を行なうことができる。 [Embodiment 1]
FIG. 1 is a diagram illustrating an example of an equivalent circuit diagram of the antenna device 1 according to the first embodiment. The antenna device 1 can perform communication according to a plurality of communication methods. The antenna device 1 can perform communication in accordance with WiFi (registered trademark) (Wireless Fidelity) and Bluetooth (registered trademark) in, for example, 2400 to 2484 MHz (2.4 GHz band).
　図１に示されるように、アンテナ装置１は、グランド導体ＧＮＤ１と、アンテナＡＮＴ１，ＡＮＴ２と、ループ部ＬＰ１１とを備える。図１においては、各構成要素間の接続関係をわかり易くするため、グランド導体ＧＮＤ１は、給電点ＦＰ１とＦＰ２とを接続する直線として描かれている。図４、図５、図８、図１１、および図１３～図１５においても同様である。 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 GND <b> 1 is drawn as a straight line connecting the feeding points FP <b> 1 and FP <b> 2 in order to make it easy to understand the connection relationship between each component. The same applies to FIG. 4, FIG. 5, FIG. 8, FIG. 11, and FIG.
　アンテナＡＮＴ１は、給電点ＦＰ１を介してグランド導体ＧＮＤ１に接続されている。アンテナＡＮＴ２は、給電点ＦＰ２を介してグランド導体ＧＮＤ１に接続されている。アンテナＡＮＴ１の共振周波数とアンテナＡＮＴ２の共振周波数とは近接している。 The antenna ANT1 is connected to the ground conductor GND1 through the feeding point FP1. The antenna ANT2 is connected to the ground conductor GND1 through the feeding point FP2. The resonance frequency of the antenna ANT1 is close to the resonance frequency of the antenna ANT2.
　ループ部ＬＰ１１は、無給電素子ＰＥ１１と、リアクタンス素子ＲＴ１１とを含む。無給電素子ＰＥ１１の端部Ｔ９は、リアクタンス素子ＲＴ１１を介してグランド導体ＧＮＤ１に接続されている。無給電素子ＰＥ１１の端部Ｔ１０は、グランド導体ＧＮＤ１に接続されている。リアクタンス素子ＲＴ１１は、接続点Ｎ１１においてグランド導体ＧＮＤ１に接続されている。リアクタンス素子ＲＴ１１は、インダクタＬ１１を含む。リアクタンス素子ＲＴ１１は、キャパシタを含んでいてもよい。 The 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. The reactance element RT11 is connected to the ground conductor GND1 at the connection point N11. The reactance element RT11 includes an inductor L11. The reactance element RT11 may include a capacitor.
　ループ部ＬＰ１１において、無給電素子ＰＥ１１、リアクタンス素子ＲＴ１１、および接続点Ｎ１１から無給電素子ＰＥ１１の端部Ｔ１２までのグランド導体ＧＮＤ１の部分により、ループ経路が形成されている。 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.
　ループ部ＬＰ１１とアンテナＡＮＴ１との容量結合は、ループ部ＬＰ１１とアンテナＡＮＴ２との容量結合よりも強い。図１において当該大小関係は、無給電素子ＰＥ１１とアンテナＡＮＴ１とがキャパシタＣ１を介して接続されている一方で、無給電素子ＰＥ１１とアンテナＡＮＴ２とはキャパシタを介して接続されていないことによって表現されている。 The capacitive coupling between the loop part LP11 and the antenna ANT1 is stronger than the capacitive coupling between the loop part LP11 and the antenna ANT2. In FIG. 1, the magnitude relationship is expressed by the fact 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.
　アンテナＡＮＴ１，ＡＮＴ２を備えるアンテナ装置１においては、アンテナＡＮＴ１とＡＮＴ２との間のアイソレーションを確保する必要がある。アンテナ装置１においては、アンテナＡＮＴ１あるいはＡＮＴ２によって受信された信号がループ部ＬＰ１１に伝達されることにより、当該信号の電力がループ部ＬＰ１１において消費される。一方のアンテナから他方のアンテナへ伝達される信号の電力が低減される。アンテナ装置１においては、ループ部ＬＰ１１によりアンテナＡＮＴ１およびアンテナＡＮＴ２の間のアイソレーションを確保することができる。 In the antenna device 1 including the antennas ANT1 and ANT2, it is necessary to ensure 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 part LP11, whereby the power of the signal is consumed in the loop part LP11. The power of the signal transmitted from one antenna to the other antenna is reduced. In the antenna device 1, the isolation between the antenna ANT1 and the antenna ANT2 can be ensured by the loop portion LP11.
　アンテナ装置１において、ループ部ＬＰ１１の共振周波数ｆ１は、アンテナＡＮＴ１あるいはＡＮＴ２が受信する信号の周波数に基づいて調整される必要がある。ループ部ＬＰ１１に含まれる無給電素子ＰＥ１１の長さは、無給電素子ＰＥ１１のインダクタンス成分に影響を与える。無給電素子ＰＥ１１の長さを変更すると、ループ部ＬＰ１１の共振周波数ｆ１が変わってしまう。アンテナＡＮＴ１およびアンテナＡＮＴ２の間のアイソレーションを確保しながら、無給電素子ＰＥ１１の長さを短くすることによりアンテナ装置１を小型化するためには、ループ部ＬＰ１１の共振周波数ｆ１を無給電素子ＰＥ１１の長さの変更以外の方法で調整する必要がある。 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 reduce the size of the antenna device 1 by shortening the length of the parasitic element PE11 while ensuring isolation between the antenna ANT1 and the antenna ANT2, the resonance frequency f1 of the loop portion LP11 is set to the parasitic element PE11. It is necessary to adjust by a method other than the change of the length.
　そこでアンテナ装置１においては、リアクタンス素子ＲＴ１１のリアクタンスを変更することによってループ部ＬＰ１１の共振周波数ｆ１を調整する。ループ部ＬＰ１１の共振周波数ｆ１は、アンテナ装置１の設計時において、無給電素子ＰＥ１１の長さ（インダクタンス成分）およびリアクタンス素子ＲＴ１１のリアクタンスによって調整可能である。無給電素子ＰＥ１１を短くする場合でも、リアクタンス素子ＲＴ１１のリアクタンスを調整することにより、ループ部ＬＰ１１がアンテナＡＮＴ１あるいはＡＮＴ２によって受信される信号に共振するようにアンテナ装置１を設計することができる。その結果、アンテナ装置を小型化することができる。 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 resonance 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 so that the loop portion LP11 resonates with a 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 reduced in size.
　図２は、図１に示されるアンテナ装置１の外観の一例を示す図である。図２において、Ｘ軸方向とＹ軸方向は互いに直交している。図６、図９、および図１２においても同様である。 FIG. 2 is a diagram 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 FIG. 6, FIG. 9, and FIG.
　図２に示されるように、グランド導体ＧＮＤ１は、Ｘ軸方向に伸びている。アンテナＡＮＴ１、ならびにループ部ＬＰ１１に含まれる無給電素子ＰＥ１１、およびリアクタンス素子ＲＴ１１は、誘電体基板１０に配置されている。アンテナＡＮＴ２は、誘電体基板２０に配置されている。 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 part LP11, and the reactance element RT11 are arranged on the dielectric substrate 10. The antenna ANT2 is disposed on the dielectric substrate 20.
　アンテナＡＮＴ１は、給電点ＦＰ１からＹ軸方向に伸び、Ｙ軸方向からＸ軸方向に屈曲する逆Ｆ型のモノポールアンテナである。アンテナＡＮＴ１は、本体部ＭＬ１と、短絡線ＳＬ１と、給電線ＦＬ１とを含む。本体部ＭＬ１は、アンテナＡＮＴ１の屈曲部ＢＰ１からＸ軸方向に伸びている。給電線ＦＬ１は、給電点ＦＰ１から屈曲部ＢＰ１までＹ軸方向に伸びている。短絡線ＳＬ１は、本体部ＭＬ１とグランド導体ＧＮＤ１とを接続している。短絡線ＳＬ１にはインダクタンス成分があるため、短絡線ＳＬ１を形成することにより、アンテナＡＮＴ１の共振周波数を所望の値に調整することができる。 The antenna ANT1 is an inverted F-type monopole antenna that extends from the feed point FP1 in the Y-axis direction and bends from the Y-axis direction to the X-axis direction. The antenna ANT1 includes a main body ML1, a short-circuit line SL1, and a feed line FL1. The main body ML1 extends in the X-axis direction from the bent portion BP1 of the antenna ANT1. The feed line FL1 extends in the Y-axis direction from the feed point FP1 to the bent portion BP1. The short-circuit line SL1 connects the main body ML1 and the ground conductor GND1. Since the short circuit line SL1 has an inductance component, the resonance frequency of the antenna ANT1 can be adjusted to a desired value by forming the short circuit line SL1.
　アンテナＡＮＴ１を逆Ｆ型のモノポールアンテナとすることにより、実装スペースを有効に活用することができる。その結果、デッドスペースが減少し、アンテナ装置１を小型化することができる。また、本体部ＭＬ１をグランド導体ＧＮＤ１から離して配置することができるため、本体部ＭＬ１とグランド導体ＧＮＤ１との容量結合を弱めることができる。その結果、本体部ＭＬ１の信号の放射能力を高めることができる。 The mounting space can be effectively utilized by making the antenna ANT1 an inverted-F monopole antenna. As a result, the dead space is reduced and the antenna device 1 can be downsized. Further, since the main body ML1 can be arranged away from the ground conductor GND1, the capacitive coupling between the main body ML1 and the ground conductor GND1 can be weakened. As a result, the signal radiation capability of the main body ML1 can be increased.
　ループ部ＬＰ１１とアンテナＡＮＴ１との距離は、ループ部ＬＰ１１とアンテナＡＮＴ２との距離よりも小さい。そのため、ループ部ＬＰ１１とアンテナＡＮＴ１との容量結合は、ループ部ＬＰ１１とアンテナＡＮＴ２との容量結合よりも強い。実施の形態１においては、ループ部ＬＰ１１をアンテナＡＮＴ１に近接させているため、ループ部ＬＰ１１とアンテナＡＮＴ２との間に誘電体基板を形成する必要がない。そのため、たとえばループ部ＬＰ１１とアンテナＡＮＴ２との間に誘電体基板の切り欠き（ノッチ）を形成することができるなど、誘電体基板の設計の自由度を高くすることができる。 The distance between the loop part LP11 and the antenna ANT1 is smaller than the distance between the loop part LP11 and the antenna ANT2. Therefore, capacitive coupling between the loop part LP11 and the antenna ANT1 is stronger than capacitive coupling between the loop part LP11 and the antenna ANT2. In the first embodiment, since the loop portion LP11 is 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, a notch (notch) of the dielectric substrate can be formed between the loop portion LP11 and the antenna ANT2, and the degree of freedom in designing the dielectric substrate can be increased.
　無給電素子ＰＥ１１は、リアクタンス素子ＲＴ１１からＹ軸方向に伸び、屈曲部ＢＰ２においてＹ軸方向からＸ軸方向に屈曲している。無給電素子ＰＥ１１は、屈曲部ＢＰ２からＸ軸方向に伸び、屈曲部ＢＰ３においてＸ軸方向からＹ軸方向に屈曲している。無給電素子ＰＥ１１は、屈曲部ＢＰ３からＹ軸方向に伸び、屈曲部ＢＰ４においてＹ軸方向からＸ軸方向に屈曲している。無給電素子ＰＥ１１は、グランド導体ＧＮＤ１からＹ軸方向に伸び、屈曲部ＢＰ５においてＹ軸方向からＸ軸方向に屈曲している。無給電素子ＰＥ１１は、屈曲部ＢＰ４からＢＰ５まで伸びている。 The parasitic element PE11 extends in the Y-axis direction from the reactance element RT11, and is bent in the bent portion BP2 from the Y-axis direction to the X-axis direction. The parasitic element PE11 extends from the bent portion BP2 in the X-axis direction, and is bent from the X-axis direction to the Y-axis direction at the bent portion BP3. The parasitic element PE11 extends from the bent portion BP3 in the Y-axis direction, and is bent in the bent portion BP4 from the Y-axis direction to the X-axis direction. The parasitic element PE11 extends from the ground conductor GND1 in the Y-axis direction, and is bent from the Y-axis direction to the X-axis direction at the bent portion BP5. The parasitic element PE11 extends from the bent part BP4 to BP5.
　無給電素子ＰＥ１１は、部分ＰＴ１および部分ＰＴ２を含む。部分ＰＴ１は、屈曲部ＢＰ２からＢＰ３までの部分である。部分ＰＴ２は、屈曲部ＢＰ４からＢＰ５までの部分である。部分ＰＴ１は、アンテナＡＮＴ１の本体部ＭＬ１とグランド導体ＧＮＤ１との間に配置されている。部分ＰＴ２とグランド導体ＧＮＤ１との距離は、部分ＰＴ１とグランド導体ＧＮＤ１との距離より大きい。 The parasitic element PE11 includes a part PT1 and a part PT2. The part PT1 is a part from the bent parts BP2 to BP3. The part PT2 is a part from the bent parts BP4 to BP5. The part PT1 is disposed between the main body 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.
　無給電素子ＰＥ１１が複数の屈曲部ＢＰ２～ＢＰ５を有することにより、限られた実装スペースの中で、できるだけ長くなるように無給電素子ＰＥ１１を配置することができる。また、実装スペースを有効に活用することができるため、デッドスペースが減少し、アンテナ装置１を小型化することができる。さらに、部分ＰＴ１と本体部ＭＬ１との距離を調整することにより、無給電素子ＰＥ１１とアンテナＡＮＴ１との容量結合を所望の強さに調整することができる。 Since the parasitic element PE11 has a plurality of bent portions BP2 to BP5, the parasitic element PE11 can be arranged to be as long as possible in a limited mounting space. Further, since the mounting space can be used effectively, the dead space is reduced and the antenna device 1 can be downsized. Furthermore, by adjusting the distance between the portion PT1 and the main body ML1, the capacitive coupling between the parasitic element PE11 and the antenna ANT1 can be adjusted to a desired strength.
　図３は、図１に示されるアンテナ装置１のアイソレーション特性ＩＳ１を示す図である。図３において縦軸の減衰量（ｄＢ）はマイナスの値として示されている。減衰量の絶対値が大きい程、一方のアンテナによって受信された信号が他方に伝わっていないことを意味するため、アンテナ間のアイソレーションは大きい。図７，図１０においても同様である。図３に示されるように、減衰量は、ループ部ＬＰ１１の共振周波数ｆ１において極小となり、－２０ｄＢ程度の減衰量が実現されている。 FIG. 3 is a diagram showing the isolation characteristic IS1 of the antenna device 1 shown in FIG. In FIG. 3, the vertical axis attenuation (dB) is shown as a negative value. The larger the absolute value of the attenuation, the greater the isolation between the antennas because 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 attenuation is minimized at the resonance frequency f1 of the loop portion LP11, and an attenuation of about −20 dB is realized.
　アンテナ装置１においては、ループ部ＬＰ１１がアンテナＡＮＴ１とＡＮＴ２との間に配置されている。ループ部ＬＰ１１は、たとえば図４に示されるアンテナ装置１Ａのように、アンテナＡＮＴ１とＡＮＴ２との間ではなく、アンテナＡＮＴ１から見て、アンテナＡＮＴ２とは反対側に配置されていてもよい。 In the antenna device 1, the loop portion LP11 is disposed between the antennas ANT1 and ANT2. The loop portion LP11 may be disposed not on the antenna ANT1 and ANT2, but on the side opposite to the antenna ANT2, as seen from the antenna ANT1, as in the antenna device 1A shown in FIG.
　以上、実施の形態１および実施の形態１の変形例に係るアンテナ装置によれば、アンテナ間のアイソレーションを確保しながら、アンテナ装置を小型化することができる。 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 downsized while ensuring the isolation between the antennas.
　［実施の形態２］
　実施の形態１においては、ループ部に含まれる無給電素子の一方端のみがリアクタンス素子を介してグランド導体に接続されている場合について説明した。実施の形態２においては、無給電素子の両端がそれぞれリアクタンス素子を介してグランド導体に接続されることにより、アンテナ間のアイソレーションをさらに大きくする場合について説明する。 [Embodiment 2]
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, a case will be described in which both ends of the parasitic element are connected to the ground conductor via the reactance element, thereby further increasing the isolation between the antennas.
　図５は、実施の形態２に係るアンテナ装置２の等価回路図の一例を示す図である。図５に示されるアンテナ装置２においては、図１に示されるアンテナ装置１のループ部ＬＰ１１がループ部ＬＰ１２に置き換えられている。ループ部ＬＰ１２以外の構成についてはアンテナ装置１と同様であるため、当該構成の説明を繰り返さない。 FIG. 5 is a diagram illustrating 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. Since the configuration other than the loop portion LP12 is the same as that of the antenna device 1, the description of the configuration will not be repeated.
　ループ部ＬＰ１２は、無給電素子ＰＥ１２と、リアクタンス素子ＲＴ１１，ＲＴ１２とを含む。無給電素子ＰＥ１２の端部Ｔ１１は、リアクタンス素子ＲＴ１１を介してグランド導体ＧＮＤ１に接続されている。無給電素子ＰＥ１２の端部Ｔ１２は、リアクタンス素子ＲＴ１２を介してグランド導体ＧＮＤ１に接続されている。 The 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.
　リアクタンス素子ＲＴ１２は、接続点Ｎ１２においてグランド導体と接続している。リアクタンス素子ＲＴ１２は、インダクタＬ１２を含む。リアクタンス素子ＲＴ１２は、キャパシタを含んでいてもよい。 The reactance element RT12 is connected to the ground conductor at the connection point N12. The reactance element RT12 includes an inductor L12. The reactance element RT12 may include a capacitor.
　ループ部ＬＰ１２において、無給電素子ＰＥ１２、リアクタンス素子ＲＴ１１、接続点Ｎ１１からＮ１２までのグランド導体ＧＮＤ１の部分、およびリアクタンス素子ＲＴ１２により、ループ経路が形成されている。ループ部ＬＰ１２の共振周波数は、実施の形態１と同様に共振周波数ｆ１である。 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.
　図６は、図５に示されるアンテナ装置２の外観の一例を示す図である。図６に示されるように、ループ部ＬＰ１２に含まれる無給電素子ＰＥ１２、およびリアクタンス素子ＲＴ１１，ＲＴ１２は、誘電体基板１０に配置されている。 FIG. 6 is a diagram 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 arranged on the dielectric substrate 10.
　図７は、図５に示されるアンテナ装置２のアイソレーション特性ＩＳ２、および図１に示されるアンテナ装置１のアイソレーション特性ＩＳ１を併せて示す図である。図７に示されるアイソレーション特性ＩＳ１は、図３に示されるアイソレーション特性ＩＳ１と同様である。 FIG. 7 is a diagram 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 the same as the isolation characteristic IS1 shown in FIG.
　図７に示されるように、ループ部ＬＰ１２の共振周波数ｆ１において、アイソレーション特性ＩＳ２の減衰量の絶対値は、アイソレーション特性ＩＳ１の減衰量の絶対値を１５ｄＢ程度上回っている。このようにアイソレーション特性ＩＳ２の減衰量の絶対値がアイソレーション特性ＩＳ１の減衰量の絶対値を上回るのは、無給電素子ＰＥ１２の両端がそれぞれリアクタンス素子ＲＴ１１，ＲＴ１２を介してグランド導体に接続されていることにより、実施の形態１よりも無給電素子ＰＥ１２における電流分布の偏りが抑制されるためである。アンテナ装置２によれば、アンテナＡＮＴ１とＡＮＴ２との間のアイソレーションをさらに大きくすることができる。 As shown in FIG. 7, at the resonance frequency f1 of the loop portion LP12, the absolute value of the attenuation amount of the isolation characteristic IS2 exceeds the absolute value of the attenuation amount of the isolation characteristic IS1 by about 15 dB. As described above, the absolute value of the attenuation amount of the isolation characteristic IS2 exceeds the absolute value of the attenuation amount of the isolation characteristic IS1 because both ends of the parasitic element PE12 are connected to the ground conductor via the reactance elements RT11 and RT12, respectively. 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.
　以上、実施の形態２に係るアンテナ装置によっても、アンテナ間のアイソレーションを確保するとともに、アンテナ装置を小型化することができる。 As described above, also with the antenna device according to Embodiment 2, it is possible to ensure isolation between the antennas and downsize the antenna device.
　さらに実施の形態２に係るアンテナ装置によれば、ループ部の無給電素子の両端がそれぞれリアクタンス素子を介してグランド導体に接続されていることにより、無給電素子における電流分布の偏りを抑制することができる。その結果、アンテナ間のアイソレーションをさらに大きくすることができる。 Furthermore, according to the antenna device according to the second embodiment, both ends of the parasitic element of the loop portion are connected to the ground conductor via the reactance elements, respectively, thereby suppressing the bias of the current distribution in the parasitic element. Can do. As a result, the isolation between the antennas can be further increased.
　［実施の形態３］
　実施の形態１および実施の形態２においては、アンテナ装置が１つのループ部を備える場合について説明した。本発明に係るアンテナ装置は、複数のループ部を備えていてもよい。実施の形態３においては、アンテナ装置が２つのループ部を備え、アンテナ毎にループ部が配置される場合について説明する。 [Embodiment 3]
In the first embodiment and the second embodiment, the case where the antenna device includes one loop unit has been described. The antenna device according to the present invention may include a plurality of loop portions. In the third embodiment, a case will be described in which the antenna device includes two loop units, and the loop unit is arranged for each antenna.
　図８は、実施の形態３に係るアンテナ装置３の等価回路図の一例を示す図である。図８に示されるアンテナ装置３においては、図５に示されるアンテナ装置２の構成にループ部ＬＰ２２が追加されている。ループ部ＬＰ２２以外の構成についてはアンテナ装置２と同様であるため、当該構成の説明を繰り返さない。 FIG. 8 is a diagram illustrating 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. Since the configuration other than the loop portion LP22 is the same as that of the antenna device 2, the description of the configuration will not be repeated.
　ループ部ＬＰ２２は、無給電素子ＰＥ２２と、リアクタンス素子ＲＴ２１，ＲＴ２２とを含む。無給電素子ＰＥ２２の端部Ｔ２１は、リアクタンス素子ＲＴ２１を介してグランド導体ＧＮＤ１に接続されている。無給電素子ＰＥ２２の端部Ｔ２２は、リアクタンス素子ＲＴ２２を介してグランド導体ＧＮＤ１に接続されている。 The 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.
　リアクタンス素子ＲＴ２１は、接続点Ｎ２１においてグランド導体ＧＮＤ１に接続されている。リアクタンス素子ＲＴ２１は、インダクタＬ２１を含む。リアクタンス素子ＲＴ２１は、キャパシタを含んでいてもよい。 The reactance element RT21 is connected to the ground conductor GND1 at the connection point N21. The reactance element RT21 includes an inductor L21. The reactance element RT21 may include a capacitor.
　リアクタンス素子ＲＴ２２は、接続点Ｎ２２においてグランド導体ＧＮＤ１に接続されている。リアクタンス素子ＲＴ２２は、インダクタＬ２２を含む。リアクタンス素子ＲＴ２２は、キャパシタを含んでいてもよい。 The reactance element RT22 is connected to the ground conductor GND1 at the connection point N22. The reactance element RT22 includes an inductor L22. The reactance element RT22 may include a capacitor.
　ループ部ＬＰ２２において、無給電素子ＰＥ２２、リアクタンス素子ＲＴ２１、接続点Ｎ２１からＮ２２までのグランド導体ＧＮＤ１の部分、およびリアクタンス素子ＲＴ２２により、ループ経路が形成されている。ループ部ＬＰ２２の共振周波数は、共振周波数ｆ２である。 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 resonance frequency of the loop portion LP22 is the resonance frequency f2.
　ループ部ＬＰ２２とアンテナＡＮＴ２と容量結合は、ループ部ＬＰ２２とアンテナＡＮＴ１との容量結合よりも強い。図８において当該大小関係は、無給電素子ＰＥ２２とアンテナＡＮＴ２とがキャパシタＣ２を介して接続されている一方で、無給電素子ＰＥ２２とアンテナＡＮＴ１とはキャパシタを介して接続されていないことによって表現されている。 The capacitive coupling between the loop part LP22 and the antenna ANT2 is stronger than the capacitive coupling between the loop part LP22 and the antenna ANT1. In FIG. 8, the magnitude relationship is expressed by the fact that the parasitic element PE22 and the antenna ANT2 are connected via the capacitor C2, while the parasitic element PE22 and the antenna ANT1 are not connected via the capacitor. ing.
　図９は、図８に示されるアンテナ装置３の外観の一例を示す図である。図９に示されるようにループ部ＬＰ２２に含まれる無給電素子ＰＥ２１、リアクタンス素子ＲＴ２１，ＲＴ２２は、誘電体基板２０に配置されている。 FIG. 9 is a diagram 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 arranged on the dielectric substrate 20.
　ループ部ＬＰ２２とアンテナＡＮＴ２との距離は、ループ部ＬＰ２２とアンテナＡＮＴ１との距離よりも小さい。そのため、ループ部ＬＰ２２とアンテナＡＮＴ２との容量結合が、ループ部ＬＰ２２とアンテナＡＮＴ１との容量結合よりも強い。実施の形態２においては、ループ部ＬＰ２２をアンテナＡＮＴ２に近接させているため、ループ部ＬＰ２２とアンテナＡＮＴ１との間に誘電体基板を形成する必要がない。そのため、たとえばループ部ＬＰ２２とアンテナＡＮＴ１との間に誘電体基板の切り欠き（ノッチ）を形成することができるなど、誘電体基板の設計の自由度を高くすることができる。 The distance between the loop part LP22 and the antenna ANT2 is smaller than the distance between the loop part LP22 and the antenna ANT1. Therefore, capacitive coupling between the loop part LP22 and the antenna ANT2 is stronger than capacitive coupling between the loop part LP22 and the antenna ANT1. In the second embodiment, since the loop part LP22 is close to the antenna ANT2, it is not necessary to form a dielectric substrate between the loop part LP22 and the antenna ANT1. Therefore, for example, a notch of the dielectric substrate can be formed between the loop portion LP22 and the antenna ANT1, and the degree of freedom in designing the dielectric substrate can be increased.
　図１０は、図８に示されるアンテナ装置３のアイソレーション特性ＩＳ３、および図５に示されるアンテナ装置２のアイソレーション特性ＩＳ２を併せて示す図である。図１０に示されるアイソレーション特性ＩＳ２は、図７に示されるアイソレーション特性ＩＳ２と同様である。図１０に示される２０００～３０００ＭＨｚの周波数帯においては、アイソレーション特性ＩＳ３の方がアイソレーション特性ＩＳ２よりも減衰量の絶対値が大きい。アイソレーション特性ＩＳ３は、ループ部ＬＰ２２の共振周波数ｆ２において減衰量の絶対値が最も大きくなっている。 FIG. 10 is a diagram showing 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 the same as 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 attenuation at the resonance frequency f2 of the loop portion LP22.
　アンテナ装置３は２つのループ部ＬＰ１２，ＬＰ２２を備えているため、アンテナＡＮＴ１あるいはＡＮＴ２で受信された信号は、ループ部ＬＰ１２に伝達されたときに当該信号のエネルギーがループ部ＬＰ１２において消費されるとともに、ループ部ＬＰ２２に伝達されたときにもループ部ＬＰ２２において当該信号のエネルギーが消費される。その結果、アイソレーション特性ＩＳ３の方がアイソレーション特性ＩＳ２よりも減衰量の絶対値が大きくなり、アンテナＡＮＴ１とＡＮＴ２との間のアイソレーションをさらに大きくすることができる。 Since the antenna device 3 includes two loop portions LP12 and LP22, when the signal received by the antenna ANT1 or ANT2 is transmitted to the loop portion LP12, the energy of the signal is consumed in the loop portion LP12. Even when the signal is transmitted to the loop part LP22, the energy of the signal is consumed in the loop part LP22. As a result, the isolation characteristic IS3 has a greater attenuation value than the isolation characteristic IS2, and the isolation between the antennas ANT1 and ANT2 can be further increased.
　以上、実施の形態３に係るアンテナ装置によっても、アンテナ間のアイソレーションを確保するとともに、アンテナ装置を小型化することができる。 As described above, also with the antenna device according to Embodiment 3, it is possible to secure isolation between the antennas and downsize the antenna device.
　さらに実施の形態３に係るアンテナ装置によれば、複数のループ部により、アンテナ間のアイソレーションをさらに大きくすることができる。 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.
　［実施の形態４］
　実施の形態１～実施の形態３においては、アンテナ装置が２本のアンテナを備える場合について説明した。本発明に係るアンテナ装置は、３本以上のアンテナを備えていてもよい。実施の形態４においては、アンテナ装置が３本のアンテナを備える場合について説明する。 [Embodiment 4]
In the first to third embodiments, 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 Embodiment 4, the case where the antenna device includes three antennas will be described.
　図１１は、実施の形態４に係るアンテナ装置４の等価回路図の一例を示す図である。図１１に示されるアンテナ装置４においては、図８に示されるアンテナ装置３の構成にアンテナＡＮＴ３、ループ部ＬＰ３２、および給電点ＦＰ３が追加されている。これら以外の構成についてはアンテナ装置３と同様であるため、当該構成の説明を繰り返さない。 FIG. 11 is a diagram illustrating 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 feed point FP3 are added to the configuration of the antenna device 3 shown in FIG. Since the configuration other than these is the same as that of the antenna device 3, the description of the configuration will not be repeated.
　アンテナＡＮＴ３は、給電点ＦＰ３を介してグランド導体ＧＮＤ１に接続されている。ループ部ＬＰ３２は、無給電素子ＰＥ３２と、リアクタンス素子ＲＴ３１，ＲＴ３２とを含む。無給電素子ＰＥ３２の端部Ｔ３１は、リアクタンス素子ＲＴ３１を介してグランド導体ＧＮＤ１に接続されている。無給電素子ＰＥ３２の端部Ｔ３２は、リアクタンス素子ＲＴ３２を介してグランド導体ＧＮＤ１に接続されている。 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.
　リアクタンス素子ＲＴ３１は、接続点Ｎ３１においてグランド導体ＧＮＤ１に接続されている。リアクタンス素子ＲＴ３１は、インダクタＬ３１を含む。リアクタンス素子ＲＴ３１は、キャパシタを含んでいてもよい。 The reactance element RT31 is connected to the ground conductor GND1 at the connection point N31. The reactance element RT31 includes an inductor L31. The reactance element RT31 may include a capacitor.
　リアクタンス素子ＲＴ３２は、接続点Ｎ３２においてグランド導体ＧＮＤ１に接続されている。リアクタンス素子ＲＴ３２は、インダクタＬ３２を含む。リアクタンス素子ＲＴ３２は、キャパシタを含んでいてもよい。 The reactance element RT32 is connected to the ground conductor GND1 at the connection point N32. The reactance element RT32 includes an inductor L32. The reactance element RT32 may include a capacitor.
　ループ部ＬＰ３２において、無給電素子ＰＥ３２、リアクタンス素子ＲＴ３１、接続点Ｎ３１からＮ３２までのグランド導体ＧＮＤ１の部分、およびリアクタンス素子ＲＴ３２により、ループ経路が形成されている。 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.
　ループ部ＬＰ３２とアンテナＡＮＴ３と容量結合は、ループ部ＬＰ３２とアンテナＡＮＴ１との容量結合よりも強く、ループ部ＬＰ３２とアンテナＡＮＴ２との容量結合よりも強い。図１１において当該大小関係は、無給電素子ＰＥ３２とアンテナＡＮＴ３とがキャパシタＣ３を介して接続されている一方で、無給電素子ＰＥ３２とアンテナＡＮＴ１，ＡＮＴ２とはキャパシタを介して接続されていないことによって表現されている。 The capacitive coupling between the loop part LP32 and the antenna ANT3 is stronger than the capacitive coupling between the loop part LP32 and the antenna ANT1, and is stronger than the capacitive coupling between the loop part LP32 and the antenna ANT2. In FIG. 11, the magnitude relationship 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.
　図１２は、図１１に示されるアンテナ装置４の外観の一例を示す図である。図１２に示されるように、アンテナＡＮＴ３、ならびにループ部ＬＰ３２に含まれる無給電素子ＰＥ３２、およびリアクタンス素子ＲＴ３１，ＲＴ３２は、誘電体基板３０に配置されている。 FIG. 12 is a diagram showing an example of the appearance of the antenna device 4 shown in FIG. As shown in FIG. 12, the antenna ANT3, the parasitic element PE32 included in the loop part LP32, and the reactance elements RT31 and RT32 are arranged on the dielectric substrate 30.
　ループ部ＬＰ３２とアンテナＡＮＴ３との距離は、ループ部ＬＰ３２とアンテナＡＮＴ１との距離よりも小さく、ループ部ＬＰ３２とアンテナＡＮＴ２との距離よりも小さい。そのため、ループ部ＬＰ３２とアンテナＡＮＴ３との容量結合が、ループ部ＬＰ３２とアンテナＡＮＴ１との容量結合よりも強く、ループ部ＬＰ３２とアンテナＡＮＴ２との容量結合よりも強い。実施の形態４においては、ループ部ＬＰ３２をアンテナＡＮＴ３に近接させることにより、ループ部ＬＰ３２とアンテナＡＮＴ１との間およびループ部ＬＰ３２とアンテナＡＮＴ２との間に誘電体基板を形成する必要がない。そのため、たとえばループ部ＬＰ３２とアンテナＡＮＴ１との間およびループ部ＬＰ３２とアンテナＡＮＴ２との間に誘電体基板の切り欠きを形成するなど、誘電体基板の設計の自由度を高くすることができる。 The distance between the loop part LP32 and the antenna ANT3 is smaller than the distance between the loop part LP32 and the antenna ANT1, and smaller than the distance between the loop part LP32 and the antenna ANT2. Therefore, capacitive coupling between the loop part LP32 and the antenna ANT3 is stronger than capacitive coupling between the loop part LP32 and the antenna ANT1, and stronger than capacitive coupling between the loop part LP32 and the antenna ANT2. In the fourth embodiment, it is not necessary to form a dielectric substrate between the loop part LP32 and the antenna ANT1 and between the loop part LP32 and the antenna ANT2 by bringing the loop part LP32 close to the antenna ANT3. Therefore, the degree of freedom in designing the dielectric substrate can be increased, for example, by forming a notch in the dielectric substrate between the loop portion LP32 and the antenna ANT1 and between the loop portion LP32 and the antenna ANT2.
　実施の形態４においては、３つのアンテナ毎にループ部が配置されている場合について説明した。３本のアンテナ毎にループ部が配置されている必要はなく、無給電素子の少なくとも一方端がリアクタンス素子を介してグランド導体に接続されているループ部が１つあれば、どのような構成であってもよい。たとえば図１３に示される実施の形態４の変形例１に係るアンテナ装置４Ａ（アンテナＡＮＴ２に対応するループ部がない場合）および図１４に示される実施の形態４の変形例２に係るアンテナ装置４Ｂ（アンテナＡＮＴ３に対応するループ部がない場合）のように、３本のアンテナのうち１本のアンテナに対応するループ部がない構成であってもよい。あるいは、図１５に示される実施の形態４の変形例３に係るアンテナ装置４Ｃ（アンテナＡＮＴ２およびアンテナＡＮＴ３に対応するループ部がない場合）のように、３本のアンテナのうち２本のアンテナに対応するループ部がない構成であってもよい。 In Embodiment 4, the case where a loop part is arranged for every three antennas has been described. There is no need for a loop portion to be arranged for every three antennas, and if there is one loop portion in which at least one end of a parasitic element is connected to a ground conductor via a reactance element, any configuration is possible. There may be. For example, antenna device 4A according to Modification 1 of Embodiment 4 shown in FIG. 13 (when there is no loop portion corresponding to antenna ANT2) and antenna device 4B according to Modification 2 of Embodiment 4 shown in FIG. The configuration may be such that there is no loop portion corresponding to one of the three antennas, as in the case where there is no loop portion corresponding to the antenna ANT3. Alternatively, two antennas out of the three antennas are used as in the antenna device 4C according to the third modification of the fourth embodiment shown in FIG. 15 (when there is no loop portion corresponding to the antenna ANT2 and the antenna ANT3). A configuration without a corresponding loop portion may be used.
　以上、実施の形態４および実施の形態４の変形例１～変形例３に係るアンテナ装置によっても、アンテナ間のアイソレーションを確保するとともに、アンテナ装置を小型化することができる。 As described above, the antenna devices according to the fourth and fourth modification examples 1 to 3 of the fourth embodiment can secure the isolation between the antennas and reduce the size of the antenna device.
　今回開示された各実施の形態は、矛盾しない範囲で適宜組み合わせて実施することも予定されている。今回開示された実施の形態はすべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は上記した説明ではなくて請求の範囲によって示され、請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。 The embodiments disclosed this time are also scheduled to be implemented in appropriate combinations within a consistent range. The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
　１～４，１Ａ，４Ａ～４Ｃ　アンテナ装置、１０，２０，３０　誘電体基板、ＡＮＴ１～ＡＮＴ３　アンテナ、ＢＰ１～ＢＰ５　屈曲部、Ｃ１～Ｃ３　キャパシタ、ＦＬ１　給電線、ＦＰ１～ＦＰ３　給電点、ＧＮＤ１　グランド導体、Ｌ１１，Ｌ１２，Ｌ２１，Ｌ２２，Ｌ３１，Ｌ３２　インダクタ、ＬＰ１１，ＬＰ１２，ＬＰ２２，ＬＰ３２　ループ部、ＭＬ１　本体部、ＰＥ１，ＰＥ１１，ＰＥ１２，ＰＥ２１，ＰＥ２２，ＰＥ３２　無給電素子、ＰＴ１，ＰＴ２　部分、ＲＴ１１，ＲＴ１２，ＲＴ２１，ＲＴ２２，ＲＴ３１，ＲＴ３２　リアクタンス素子、ＳＬ１　短絡線。 1 to 4, 1A, 4A to 4C antenna device 10, 20, 30 dielectric substrate, ANT1 to ANT3 antenna, BP1 to BP5 bent part, C1 to C3 capacitor, FL1 feeder, FP1 to FP3 feeder, 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 reactance element, SL1 short circuit wire.

Claims (14)

  1. 　グランド導体と、
    　前記グランド導体に電気的に接続された第１アンテナおよび第２アンテナと、
    　第１無給電素子と第１リアクタンス素子とを含む第１ループ部とを備え、
    　前記第１無給電素子は、前記第１無給電素子の一方端が前記グランド導体に電気的に接続されているとともに、前記第１無給電素子の他方端が前記第１リアクタンス素子を介して前記グランド導体に接続されている、アンテナ装置。     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 connected to the ground via the first reactance element. An antenna device connected to a ground conductor.
  2. 　前記第１ループ部と前記第１アンテナとの距離は、前記第１ループ部と前記第２アンテナとの距離よりも小さい、請求項１に記載のアンテナ装置。 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.
  3. 　前記第１ループ部は、前記第１アンテナに近接している、請求項２に記載のアンテナ装置。 The antenna device according to claim 2, wherein the first loop portion is close to the first antenna.
  4. 　前記第１リアクタンス素子は、インダクタを有する、請求項１～請求項３のいずれか１項に記載のアンテナ装置。 The antenna device according to any one of claims 1 to 3, wherein the first reactance element includes an inductor.
  5. 　前記グランド導体は、第１方向に伸び、
    　前記第１無給電素子は、前記第１方向と直交する第２方向に伸び、前記第２方向から前記第１方向に屈曲している屈曲部を有する、請求項１～請求項４のいずれか１項に記載のアンテナ装置。     The ground conductor extends in a first direction;
    The first parasitic element has a bent portion that extends in a second direction orthogonal to the first direction and is bent in the first direction from the second direction. The antenna device according to item 1.
  6. 　前記第１アンテナは、前記第２方向から前記第１方向に屈曲するモノポールアンテナである、請求項５に記載のアンテナ装置。 The antenna device according to claim 5, wherein the first antenna is a monopole antenna bent from the second direction to the first direction.
  7. 　前記第１無給電素子は、前記第１方向に沿う第１部分および第２部分を含み、
    　前記第１部分は、前記第１アンテナの前記第１方向に沿う特定部分と前記グランド導体との間に配置され、
    　前記第２部分と前記グランド導体との距離は、前記第１部分と前記グランド導体との距離より大きい、請求項６に記載のアンテナ装置。     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 apparatus according to claim 6, wherein a distance between the second portion and the ground conductor is greater than a distance between the first portion and the ground conductor.
  8. 　前記特定部分を前記グランド導体に接続する短絡導体をさらに備える、請求項７に記載のアンテナ装置。 The antenna device according to claim 7, further comprising a short-circuit conductor that connects the specific portion to the ground conductor.
  9. 　前記第１ループ部は、第２リアクタンス素子をさらに含み、
    　前記第１無給電素子の前記一方端は、前記第２リアクタンス素子を介して前記グランド導体に接続されている、請求項１～請求項８のいずれか１項に記載のアンテナ装置。     The first loop part 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.
  10. 　第２ループ部をさらに備え、
    　前記第２ループ部と前記第２アンテナとの距離は、前記第２ループ部と前記第１アンテナとの距離よりも小さい、請求項１～請求項９のいずれか１項に記載のアンテナ装置。     A second loop portion;
    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.
  11. 　前記第２ループ部は、前記第２アンテナに近接している、請求項１０に記載のアンテナ装置。 The antenna device according to claim 10, wherein the second loop unit is close to the second antenna.
  12. 　前記グランド導体に電気的に接続された第３アンテナをさらに備え、
    　前記第１ループ部と前記第１アンテナとの距離は、前記第１ループ部と前記第３アンテナとの距離よりも小さく、
    　前記第２ループ部と前記第２アンテナとの距離は、前記第２ループ部と前記第３アンテナとの距離よりも小さい、請求項１０または請求項１１に記載のアンテナ装置。     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 or 11, 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.
  13. 　第３ループ部をさらに備え、
    　前記第３ループ部と前記第３アンテナとの距離は、前記第３ループ部と前記第１アンテナとの距離よりも小さく、前記第３ループ部と前記第２アンテナとの距離よりも小さい、請求項１２に記載のアンテナ装置。     A third loop portion;
    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. Item 13. The antenna device according to Item 12.
  14. 　前記第３ループ部は、前記第３アンテナに近接している、請求項１３に記載のアンテナ装置。 The antenna device according to claim 13, wherein the third loop portion is close to the third antenna.
PCT/JP2017/041650 2016-12-27 2017-11-20 Antenna device WO2018123345A1 (en)

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JP2005198245A (en) * 2003-12-10 2005-07-21 Matsushita Electric Ind Co Ltd Antenna
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CN110121815A (en) 2019-08-13
CN110121815B (en) 2021-04-16
JPWO2018123345A1 (en) 2019-07-11

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