WO2014007087A1 - Antenna apparatus - Google Patents

Antenna apparatus Download PDF

Info

Publication number
WO2014007087A1
WO2014007087A1 PCT/JP2013/067180 JP2013067180W WO2014007087A1 WO 2014007087 A1 WO2014007087 A1 WO 2014007087A1 JP 2013067180 W JP2013067180 W JP 2013067180W WO 2014007087 A1 WO2014007087 A1 WO 2014007087A1
Authority
WO
WIPO (PCT)
Prior art keywords
antenna
ground conductor
slit
substrate
chip antenna
Prior art date
Application number
PCT/JP2013/067180
Other languages
French (fr)
Japanese (ja)
Inventor
楠本裕亮
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
Publication of WO2014007087A1 publication Critical patent/WO2014007087A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
    • H01Q1/38—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith formed by a conductive layer on an insulating support
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/48—Earthing means; Earth screens; Counterpoises

Definitions

  • the present invention relates to an antenna device including a substrate and a chip antenna mounted on the substrate, and in particular, mobile communication devices such as mobile phone terminals, GPS receivers, and short-range wireless devices such as Bluetooth (registered trademark).
  • the present invention relates to a small antenna device used for an electronic device having a communication function.
  • an antenna device having a chip antenna is often used.
  • the chip antenna is mounted on a predetermined mounting area on the substrate.
  • the chip antenna mounting portion with the ground conductor removed from the front and back surfaces is a so-called non-ground (Non GND) type antenna, and the chip antenna mounting portion with the ground conductor on the back surface is so-called. It is called an on-ground (On GND) type antenna.
  • Patent Document 1 discloses an antenna device in which stable characteristics can be obtained even if the mounting position of the chip antenna on the substrate varies.
  • the current flowing through the ground conductor formed on the substrate is important.
  • the conventional antenna device provided with the chip antenna there is hardly anything that controls the antenna characteristics by designing the pattern of the ground conductor of the substrate, and the ground conductor on the back surface of the chip antenna mounting area is not patterned.
  • a current in the reverse direction flows in the ground conductor of the substrate with respect to the current flowing in the radiation electrode of the chip antenna. It tends to be canceled out by electromagnetic field radiation.
  • this phenomenon is referred to as “cancellation effect due to reverse-phase current”.
  • it is important to allow a current to flow through the entire ground conductor of the substrate so that the ground conductor of the substrate operates as an antenna, but the amount of current flowing through the entire substrate is reduced by the reverse phase current.
  • An object of the present invention is to provide an antenna device having improved antenna characteristics in consideration of a current flowing through a ground conductor formed on a substrate on which a chip antenna is mounted.
  • the antenna device of the present invention is configured as follows.
  • a chip antenna including a dielectric substrate and a radiation electrode formed on the dielectric substrate, and a substrate including a base material and a ground conductor formed on the base material.
  • the radiation electrode has a first end grounded to the ground conductor and a capacitive power supply from a second end, A slit is formed in a region facing the mounting surface of the chip antenna in the ground conductor formation region.
  • the reverse phase current becomes smaller as the radiating electrode is further away from the ground conductor, the height dimension of the dielectric substrate of the chip antenna is increased and the radiating electrode is formed on the upper surface of the dielectric substrate. Is effective for improving the antenna efficiency, but according to the present invention, since the cancellation action due to the reverse phase current is suppressed without increasing the chip antenna, the chip antenna can be reduced in height accordingly. .
  • the slit is formed at a position closer to the second end than the first end within a range facing the mounting surface of the chip antenna in a ground conductor forming region.
  • the slit extends in a direction orthogonal to a direction in which the radiation electrode extends.
  • the present invention when the electric field leaks from the slit, the amount of current induced in the ground conductor of the substrate increases, and the amount of radiation from the ground conductor increases. Furthermore, the reverse phase current, which tends to flow through the ground conductor of the substrate, is suppressed by the slit, and the influence of the canceling action due to the reverse phase current can be weakened. As a result, antenna efficiency can be improved. In addition, since it is not necessary to increase the height from the ground conductor of the substrate to the radiation electrode of the chip antenna, the height of the chip antenna can be reduced and the antenna device can be downsized.
  • FIG. 1 is a partial perspective view of an antenna device 301 according to an embodiment of the present invention.
  • FIG. 2 is a plan view of the antenna device 301.
  • 3A is a partial plan view of the antenna device 301, and
  • FIG. 3B is a plan view showing a conductor pattern on the substrate before the chip antenna 101, the matching element 31 and the characteristic adjustment element 32 are mounted.
  • FIG. 4A, FIG. 4B, and FIG. 4C are diagrams showing the relationship between the mounting position of the chip antenna and the conductor pattern on the lower surface of the substrate.
  • FIG. 5 is a perspective view showing the distribution of electric field strength near the chip antenna 101 and its mounting position.
  • FIGS. 6A and 6B are front views showing the distribution of electric field strength for two antenna devices having different slit positions.
  • FIGS. 7A and 7B are diagrams showing current flowing through the lower surface ground conductor 22, and particularly showing current flowing near a position facing the mounting surface of the chip antenna 101.
  • FIG. 8 is a diagram illustrating a change in antenna efficiency when the position and length of the slit SL are changed.
  • FIG. 9 is a partial bottom view of a substrate in an antenna device different from the antenna device shown in FIGS.
  • FIG. 10 is a partial bottom view of a substrate in still another antenna device different from the antenna device shown in FIGS.
  • FIG. 1 is a partial perspective view of an antenna device 301 according to an embodiment of the present invention
  • FIG. 2 is a plan view of the antenna device.
  • the antenna device 301 includes a substrate 201 and a chip antenna 101 mounted on the substrate 201.
  • the chip antenna 101 includes a rectangular parallelepiped dielectric base 10, and a radiation electrode 11, a feeding electrode 12, a ground electrode 13 and the like formed on the dielectric base 10.
  • the substrate 201 includes a dielectric or insulating base material 20, a power supply terminal 23 formed on the base material 20, a power supply line 24, a power supply electrode connection terminal 25, a ground electrode connection terminal 26, a back electrode connection terminal 29, An upper surface ground conductor 21 and a lower surface ground conductor 22 are included.
  • the upper surface ground conductor 21 is electrically connected to the lower surface ground conductor 22 through a plurality of plated-through holes PTH.
  • the radiation electrode 11 of the chip antenna 101 extends to the left rear end face of the dielectric substrate 10, and the first end of the radiation electrode 11 (the lower end of the left rear end face of the dielectric substrate 10) is the substrate 201. Connected (grounded) to the upper surface ground conductor 21.
  • a gap GA ⁇ b> 1 is formed between the second end 11 ⁇ / b> S of the radiation electrode 11 and the power supply electrode 12.
  • a capacitance is generated between the radiation electrode 11 and the feeding electrode 12 in the gap GA1. That is, the radiation electrode 11 is capacitively fed via the feeding electrode 12.
  • a first end of the ground electrode 13 is connected to the upper surface ground conductor 21 of the substrate 201.
  • a gap GA ⁇ b> 2 is formed between the ground electrode 13 and the radiation electrode 11.
  • a capacitance is generated between the radiation electrode 11 and the ground electrode 13 in the gap GA2. That is, the capacitance between the radiation electrode 11 and the ground is determined by the gap GA2.
  • a radiation electrode counter electrode facing the radiation electrode 11 on the upper surface is formed.
  • the feed electrode 12 of the chip antenna 101 is connected to the feed electrode connection terminal 25.
  • the ground electrode 13 is connected to the ground electrode connection terminal 26.
  • the back electrode formed on the lower surface of the chip antenna 101 is connected to the connection electrode.
  • the connection terminal 29 is drawn from this connection electrode.
  • a matching element 31 is connected between the power supply line 24 connecting the power supply terminal 23 and the power supply electrode connection terminal 25 and the upper surface ground conductor 21.
  • a characteristic adjusting element 32 is connected between the connection terminal 29 of the back electrode and the upper surface ground conductor 21.
  • FIG. 3A is a partial plan view of the antenna device 301
  • FIG. 3B is a plan view showing a conductor pattern on the substrate before the chip antenna 101, the matching element 31 and the characteristic adjustment element 32 are mounted.
  • FIG. 3B a two-dot chain line represents a range facing the mounting surface of the chip antenna 101. In this range, the connection electrode 28, the feeding electrode connection terminal 25, the ground electrode connection terminal 26, and the connection terminals 27a and 27b of the radiation electrode ground end are formed.
  • the matching element 31 is, for example, a chip inductor or a chip capacitor, and matches the impedance of the power feeding circuit connected to the power feeding terminal 23 with the impedance of the chip antenna 101.
  • the power supply terminal 23 is simply shown in each figure. A power feeding circuit is connected to the power feeding terminal 23.
  • the characteristic adjusting element 32 is a chip capacitor for finely adjusting the capacitance between the connection electrode 28 of the back electrode and the ground conductor 21.
  • the resonance frequency of the antenna device 301 is determined by the inductance of the radiation electrode 11 of the chip antenna 101, the capacitance between the radiation electrode 11 and the back electrode and the capacitance of the characteristic adjustment element 32. The resonance frequency of the antenna device 301 can be determined.
  • FIGS. 4B and 4C are diagrams showing the relationship between the mounting position of the chip antenna and the conductor pattern on the lower surface of the substrate.
  • 4A is a partial plan view in the vicinity of the mounting position of the chip antenna 101
  • FIGS. 4B and 4C are partial plan views on the back side of the mounting position of the chip antenna 101.
  • FIG. FIG. 4B is a diagram illustrating the antenna device 301
  • FIG. 4C is a diagram illustrating the antenna device of the comparative example. 4B and 4C, a two-dot chain line represents a range facing the mounting surface of the chip antenna 101.
  • the antenna device 301 is an on-ground type antenna in which the mounting surface of the chip antenna 101 is mounted to face the lower surface ground conductor 22.
  • GE is a position corresponding to the grounding position (first end) of the radiation electrode 11
  • OE is a position corresponding to the capacity feeding position (second end) of the radiation electrode 11.
  • the lower surface ground conductor 22 has a slit SL formed in a range facing the mounting surface of the chip antenna 101.
  • the slit SL is a portion where the lower surface ground conductor 22 is not formed.
  • One end of the slit SL is opened at the edge 22E of the lower surface ground conductor 22.
  • the slit SL extends from the edge 22E of the lower surface ground conductor 22 inward by a dimension D in a direction orthogonal to the direction in which the radiation electrode 11 extends.
  • the slit SL shown in FIG. 4B is formed near the capacitive power supply position OE within the range from the position GE corresponding to the grounding position of the radiation electrode 11 to the position OE corresponding to the capacitive power supply position.
  • the slit SL shown in FIG. 4C is formed near the position GE corresponding to the ground contact position within the above range.
  • FIG. 5 is a perspective view showing the distribution of electric field strength near the chip antenna 101 and its mounting position.
  • the intensity of the electric field is expressed by concentration.
  • a strong electric field is generated around the second end 11 ⁇ / b> S of the radiation electrode 11.
  • 6 (A) and 6 (B) are front views showing electric field intensity distributions for two antenna devices having different slit positions.
  • 6A shows the electric field strength of the antenna device 301A in which the slit SL is formed at the position shown in FIG. 4B, that is, the antenna device in which the slit SL is formed at the opposite position on the capacitive feeding side where electric field strength is high.
  • FIG. 6B shows the electric field strength of the antenna device 301B in which the slit SL is formed at the position shown in FIG. 4C, that is, the antenna device in which the slit SL is formed at the opposite position on the low electric field strength side. Yes. In either case, the intensity of the electric field is expressed as a concentration.
  • the electric field is applied to the substrate 201 from the slit SL. Leak to the bottom side. Therefore, the amount of current induced in the lower surface ground conductor 22 of the substrate increases, and the amount of radiation from the substrate increases. This effect also improves the antenna efficiency (radiation capability).
  • the ground conductor formed on the substrate also acts as a shield conductor that prevents interference with other electronic components and circuits
  • the slit SL opens the ground conductor in a slit shape, that is, the ground conductor Since the opening area of the ground conductor is small in the conductor forming region, the shielding effect of the ground conductor is hardly lowered.
  • FIG. 7 (A) and 7 (B) are diagrams showing the current flowing through the lower surface ground conductor 22, and particularly showing the current flowing near the position facing the mounting surface of the chip antenna 101.
  • FIG. 7A illustrates the antenna device 301
  • FIG. 7B illustrates the antenna device of the comparative example.
  • the slit SL is formed, as shown in FIG. 7A, when the current ECf flows through the radiation electrode of the chip antenna 101, the current ECr is induced in the lower surface ground conductor 22 of the substrate. ECr is suppressed by the slit SL.
  • the slit SL is formed in the range of the ground conductor formation region facing the mounting surface of the chip antenna 101, the canceling action due to the reverse phase current can be reduced, and as a result, the antenna efficiency is improved.
  • the slit SL extends in a direction orthogonal to the direction in which the radiation electrode of the chip antenna 101 extends, a negative phase current that tends to flow to the ground conductor 22 even with a slit having a short slit length D can be effectively suppressed.
  • the inductance of the ground conductor changes depending on the presence / absence of the slit SL and the formation position, and the resonance frequency of the antenna device changes slightly. Therefore, the resonance frequency shift caused by the formation of the slit can be reduced. Fine adjustment may be made by capacitance.
  • FIG. 8 is a diagram showing changes in antenna efficiency when the position and length of the slit SL are changed.
  • the improvement amount of the antenna efficiency with respect to the slit length D is plotted on the basis of the case where there is no slit SL.
  • the dimension of the mounting surface of the chip antenna 101 is 3.0 ⁇ 9.8 mm, and the height dimension is 3.0 mm.
  • the thickness dimension of the substrate 201 is 1.0 mm.
  • the antenna device 301A is an antenna device in which slits SL are formed at opposing positions on the capacitive power feeding side where electric field strength is high.
  • the antenna device 301B is an antenna device in which a slit SL is formed at a position where the electric field strength is low.
  • the antenna device 301A (antenna device in which the slit SL is formed at a position opposite to the capacitive power feeding side with high electric field strength) is compared with the antenna device 301B (antenna device in which the slit SL is formed in a position on the low electric field strength side). It can be seen that the improvement in antenna efficiency is large. In the case of the antenna device 301B, the improvement amount of the antenna efficiency hardly changes depending on the change of the slit length D, but in the antenna device 301A, the improvement amount of the antenna efficiency becomes larger as the slit length D becomes longer. From this, it can be seen that as the slit length D increases, the radiation amount due to leakage of the electric field from the slit SL increases, and the antenna efficiency is improved.
  • the current induced in the ground conductor of the substrate by the current flowing through the radiation electrode of the chip antenna decreases as the distance between the radiation electrode and the ground conductor decreases, so the height dimension of the dielectric substrate of the chip antenna is increased.
  • forming the radiation electrode on the upper surface of the dielectric substrate is effective for improving the antenna efficiency.
  • the “cancellation effect due to the reverse phase current” can be achieved without increasing the chip antenna. "Is suppressed, the chip antenna can be reduced in height accordingly.
  • 9 and 10 are partial bottom views of a substrate in an antenna device different from the antenna device shown above.
  • the configuration of the upper surface of the substrate and the configuration of the chip antenna mounted on the upper surface of the substrate are the same as those shown in FIG.
  • the slit SL is T-shaped. Even in this shape, the antenna efficiency is improved because of the leakage action of the electric field from the slit SL and the suppression action of the reverse phase current.
  • the slit does not necessarily have a shape extending in one direction, and may include a portion extending in a plurality of directions.
  • the slit SL is inclined with respect to the extending direction of the radiation electrode of the chip antenna. Even in this shape, the slit SL is non-parallel to the direction in which the radiation electrode extends, and thus has an action of leaking an electric field from the slit SL and an action of suppressing a reverse phase current. Therefore, antenna efficiency is improved.
  • the direction in which the slit extends does not necessarily have to be orthogonal to the direction in which the radiation electrode extends, and may be inclined.
  • the slit SL extends from the position GE corresponding to the grounding position of the radiation electrode 11 to the position OE corresponding to the capacitive power supply position. Although it is formed within the range, it may protrude from this range.
  • the ground conductor forming region is closer to the position corresponding to the grounding position than the position corresponding to the capacitive power feeding position within the range facing the mounting surface of the chip antenna. Even if formed, the antenna efficiency can be improved.
  • the mounting surface of the chip antenna is not limited to the on-ground type antenna that is mounted facing the ground conductor of the substrate, but a part of the mounting surface of the chip antenna is mounted facing the ground conductor of the substrate.
  • the antenna device can be similarly applied because an electric current is induced in the ground conductor of the substrate.

Landscapes

  • Details Of Aerials (AREA)

Abstract

An antenna apparatus is provided with: a chip antenna (101) including a dielectric block and a radiating electrode formed on the dielectric block; and a substrate (201) including a base material and a ground conductor formed on the base material. The radiating electrode of the chip antenna (101) has a first end grounded to the ground conductor and is capacitively fed via a second end. A slit (SL) is formed in an area opposite the mounting surface of the chip antenna (101). In this configuration, an electric field leaks via the slit, whereby the amount of current induced in the ground conductor of the substrate is increased, and the amount of radiation from the ground conductor is increased. Further, the inverse phase current (ECr) that would flow into the ground conductor of the substrate is suppressed by the slit.

Description

アンテナ装置Antenna device
　この発明は、基板とこの基板に実装されたチップアンテナとで構成されるアンテナ装置に関し、特に、携帯電話端末、ＧＰＳ受信機などの移動体通信機器、Bluetooth（登録商標）のような近距離無線通信機能を有する電子機器に用いられる小型のアンテナ装置に関するものである。 The present invention relates to an antenna device including a substrate and a chip antenna mounted on the substrate, and in particular, mobile communication devices such as mobile phone terminals, GPS receivers, and short-range wireless devices such as Bluetooth (registered trademark). The present invention relates to a small antenna device used for an electronic device having a communication function.
　移動体通信機器や近距離無線通信機能を有する電子機器においては、チップアンテナを備えたアンテナ装置が多く用いられる。前記チップアンテナは基板上の所定の実装領域に実装される。このチップアンテナの実装部の表裏面のグランド導体を抜いた（非グランド領域とした）ものは所謂ノングランド（Non GND）タイプのアンテナ、チップアンテナの実装部の裏面にグランド導体を有するものは所謂オングランド（On GND）タイプのアンテナと呼ばれる。 In mobile communication devices and electronic devices having a short-range wireless communication function, an antenna device having a chip antenna is often used. The chip antenna is mounted on a predetermined mounting area on the substrate. The chip antenna mounting portion with the ground conductor removed from the front and back surfaces (non-ground area) is a so-called non-ground (Non GND) type antenna, and the chip antenna mounting portion with the ground conductor on the back surface is so-called. It is called an on-ground (On GND) type antenna.
　いずれのタイプのアンテナ装置においても、チップアンテナと基板のグランド導体との位置関係はアンテナ特性上重要である。例えば特許文献１には、基板に対するチップアンテナの実装位置がばらついても安定した特性が得られるようにしたアンテナ装置が開示されている。 In any type of antenna device, the positional relationship between the chip antenna and the ground conductor of the substrate is important for antenna characteristics. For example, Patent Document 1 discloses an antenna device in which stable characteristics can be obtained even if the mounting position of the chip antenna on the substrate varies.
特開２００３－１２４７２５号公報JP 2003-124725 A
　オングランドタイプのアンテナにおいては、基板に形成されているグランド導体に流れる電流が重要である。しかし、チップアンテナを備えた従来のアンテナ装置においては基板のグランド導体のパターン設計によってアンテナ特性を制御するものは殆ど無く、チップアンテナの実装領域の裏面のグランド導体についてはパターン化されていなかった。 In the on-ground type antenna, the current flowing through the ground conductor formed on the substrate is important. However, in the conventional antenna device provided with the chip antenna, there is hardly anything that controls the antenna characteristics by designing the pattern of the ground conductor of the substrate, and the ground conductor on the back surface of the chip antenna mounting area is not patterned.
　また、オングランドタイプのアンテナ装置においては、チップアンテナの放射電極に流れる電流に対して基板のグランド導体には逆方向（逆相）の電流が流れるため、放射電極による電磁界放射がグランド導体による電磁界放射で打ち消される傾向にある。以降、この現象を「逆相電流による打ち消し作用」という。オングランドアンテナの場合、基板のグランド導体全体に電流を流して基板のグランド導体をアンテナとして動作させることが重要であるが、前記逆相電流により基板全体に流れる電流量が減少してしまう。 Further, in the on-ground type antenna device, a current in the reverse direction (reverse phase) flows in the ground conductor of the substrate with respect to the current flowing in the radiation electrode of the chip antenna. It tends to be canceled out by electromagnetic field radiation. Hereinafter, this phenomenon is referred to as “cancellation effect due to reverse-phase current”. In the case of an on-ground antenna, it is important to allow a current to flow through the entire ground conductor of the substrate so that the ground conductor of the substrate operates as an antenna, but the amount of current flowing through the entire substrate is reduced by the reverse phase current.
　この発明の目的は、チップアンテナが実装される基板に形成されているグランド導体に流れる電流を考慮して、アンテナ特性を改善したアンテナ装置を提供しようとするものである。 An object of the present invention is to provide an antenna device having improved antenna characteristics in consideration of a current flowing through a ground conductor formed on a substrate on which a chip antenna is mounted.
　本発明のアンテナ装置は次のように構成される。 The antenna device of the present invention is configured as follows.
（１）誘電体基体およびこの誘電体基体に形成された放射電極を含んで構成されるチップアンテナと、基材およびこの基材に形成されたグランド導体を含んで構成される基板と、を備え、前記基板に前記チップアンテナが実装されて構成されたアンテナ装置において、
　前記放射電極は第１端が前記グランド導体に接地され、且つ第２端から容量給電され、
　前記グランド導体の形成領域のうち前記チップアンテナの実装面に対向する範囲内にスリットが形成されたことを特徴とする。 (1) A chip antenna including a dielectric substrate and a radiation electrode formed on the dielectric substrate, and a substrate including a base material and a ground conductor formed on the base material. In the antenna device configured by mounting the chip antenna on the substrate,
The radiation electrode has a first end grounded to the ground conductor and a capacitive power supply from a second end,
A slit is formed in a region facing the mounting surface of the chip antenna in the ground conductor formation region.
　この構成により、スリットから電界が漏れ出すことにより、基板のグランド導体に誘起される電流量が増え、グランド導体からの放射量が増大する。また、基板のグランド導体に流れようとする、チップアンテナの放射電極に流れる電流とは逆相の電流（逆相電流）がスリットで抑制されることになり、逆相電流による打ち消し作用の影響を弱めることができる。特にチップアンテナの実装面に対向する範囲内にスリットを設けることによって逆相電流による打ち消し作用が大きくなる。その結果、アンテナ効率を改善できる。 With this configuration, an electric field leaks from the slit, thereby increasing the amount of current induced in the ground conductor of the substrate and increasing the amount of radiation from the ground conductor. In addition, the current that is opposite to the current flowing through the radiation electrode of the chip antenna that is going to flow through the ground conductor of the substrate (reverse phase current) is suppressed by the slit, and the influence of the canceling action due to the reverse phase current is reduced. Can weaken. Particularly, by providing a slit in a range facing the mounting surface of the chip antenna, the canceling action due to the reverse phase current is increased. As a result, antenna efficiency can be improved.
　また、前記逆相電流は、放射電極がグランド導体から離れているほど小さくなるので、チップアンテナの誘電体基体の高さ寸法を大きくするとともに、この誘電体基体の上面に放射電極を形成することはアンテナ効率の向上のために有効であるが、本発明によれば、チップアンテナを高くしなくても前記逆相電流による打ち消し作用が抑制されるので、その分、チップアンテナを低背化できる。 Further, since the reverse phase current becomes smaller as the radiating electrode is further away from the ground conductor, the height dimension of the dielectric substrate of the chip antenna is increased and the radiating electrode is formed on the upper surface of the dielectric substrate. Is effective for improving the antenna efficiency, but according to the present invention, since the cancellation action due to the reverse phase current is suppressed without increasing the chip antenna, the chip antenna can be reduced in height accordingly. .
（２）前記スリットは、グランド導体の形成領域のうち、前記チップアンテナの実装面に対向する範囲内で、前記第１端よりも前記第２端寄りの位置に形成されていることが好ましい。この構成により、電界強度の高い位置にスリットが配置されることになるので、基板の下面からの電界の漏れ出しが大きくなり、アンテナ効率が向上する。 (2) Preferably, the slit is formed at a position closer to the second end than the first end within a range facing the mounting surface of the chip antenna in a ground conductor forming region. With this configuration, since the slit is disposed at a position where the electric field strength is high, the leakage of the electric field from the lower surface of the substrate is increased, and the antenna efficiency is improved.
（３）前記スリットは前記放射電極の延びる方向に対し直交方向に延びていることが好ましい。この構成により、小さなスリットでも逆相電流の抑制効果が得られる。 (3) It is preferable that the slit extends in a direction orthogonal to a direction in which the radiation electrode extends. With this configuration, a negative phase current suppressing effect can be obtained even with a small slit.
　本発明によれば、スリットから電界が漏れ出すことにより、基板のグランド導体に誘起される電流量が増え、グランド導体からの放射量が増大する。さらに、基板のグランド導体に流れようとする、前記逆相電流がスリットで抑制されることになり、逆相電流による打ち消し作用の影響を弱めることができる。その結果、アンテナ効率を改善できる。また、基板のグランド導体からチップアンテナの放射電極までの高さを高くしなくてもよいのでチップアンテナを低背化でき、アンテナ装置を小型化できる。 According to the present invention, when the electric field leaks from the slit, the amount of current induced in the ground conductor of the substrate increases, and the amount of radiation from the ground conductor increases. Furthermore, the reverse phase current, which tends to flow through the ground conductor of the substrate, is suppressed by the slit, and the influence of the canceling action due to the reverse phase current can be weakened. As a result, antenna efficiency can be improved. In addition, since it is not necessary to increase the height from the ground conductor of the substrate to the radiation electrode of the chip antenna, the height of the chip antenna can be reduced and the antenna device can be downsized.
図１は本発明の実施形態に係るアンテナ装置３０１の部分斜視図である。FIG. 1 is a partial perspective view of an antenna device 301 according to an embodiment of the present invention. 図２はアンテナ装置３０１の平面図である。FIG. 2 is a plan view of the antenna device 301. 図３（Ａ）はアンテナ装置３０１の部分平面図、図３（Ｂ）はチップアンテナ１０１、整合用素子３１および特性調整用素子３２を実装する前の状態での基板上の導体パターンを示す平面図である。3A is a partial plan view of the antenna device 301, and FIG. 3B is a plan view showing a conductor pattern on the substrate before the chip antenna 101, the matching element 31 and the characteristic adjustment element 32 are mounted. FIG. 図４（Ａ）、図４（Ｂ）、図４（Ｃ）は、チップアンテナの実装位置と基板の下面の導体パターンとの関係を示す図である。FIG. 4A, FIG. 4B, and FIG. 4C are diagrams showing the relationship between the mounting position of the chip antenna and the conductor pattern on the lower surface of the substrate. 図５はチップアンテナ１０１およびその実装位置付近の電界強度の分布を示す斜視図である。FIG. 5 is a perspective view showing the distribution of electric field strength near the chip antenna 101 and its mounting position. 図６（Ａ）、図６（Ｂ）はスリットの位置が異なる二つのアンテナ装置について、電界強度の分布を示す正面図である。FIGS. 6A and 6B are front views showing the distribution of electric field strength for two antenna devices having different slit positions. 図７（Ａ）、図７（Ｂ）は下面グランド導体２２に流れる電流を示す図であり、特にチップアンテナ１０１の実装面に対向する位置付近に流れる電流について示している。FIGS. 7A and 7B are diagrams showing current flowing through the lower surface ground conductor 22, and particularly showing current flowing near a position facing the mounting surface of the chip antenna 101. 図８はスリットＳＬの位置や長さを変化させた場合のアンテナ効率の変化を示す図である。FIG. 8 is a diagram illustrating a change in antenna efficiency when the position and length of the slit SL are changed. 図９は図１～図４に示したアンテナ装置とは異なるアンテナ装置における基板の部分下面図である。FIG. 9 is a partial bottom view of a substrate in an antenna device different from the antenna device shown in FIGS. 図１０は図１～図４に示したアンテナ装置とは異なるさらに別のアンテナ装置における基板の部分下面図である。FIG. 10 is a partial bottom view of a substrate in still another antenna device different from the antenna device shown in FIGS.
　図１は本発明の実施形態に係るアンテナ装置３０１の部分斜視図、図２はこのアンテナ装置の平面図である。アンテナ装置３０１は基板２０１とこの基板２０１に実装されたチップアンテナ１０１とで構成されている。 FIG. 1 is a partial perspective view of an antenna device 301 according to an embodiment of the present invention, and FIG. 2 is a plan view of the antenna device. The antenna device 301 includes a substrate 201 and a chip antenna 101 mounted on the substrate 201.
　チップアンテナ１０１は、直方体形状の誘電体基体１０およびこの誘電体基体１０に形成された放射電極１１、給電電極１２、接地電極１３等を含む。基板２０１は、誘電体または絶縁体の基材２０と、この基材２０に形成された給電端子２３、給電線路２４、給電電極接続端子２５、接地電極接続端子２６、裏面電極の接続端子２９、上面グランド導体２１および下面グランド導体２２を含む。上面グランド導体２１は複数のスルーホール（plated through hole）ＰＴＨを介して下面グランド導体２２と導通している。 The chip antenna 101 includes a rectangular parallelepiped dielectric base 10, and a radiation electrode 11, a feeding electrode 12, a ground electrode 13 and the like formed on the dielectric base 10. The substrate 201 includes a dielectric or insulating base material 20, a power supply terminal 23 formed on the base material 20, a power supply line 24, a power supply electrode connection terminal 25, a ground electrode connection terminal 26, a back electrode connection terminal 29, An upper surface ground conductor 21 and a lower surface ground conductor 22 are included. The upper surface ground conductor 21 is electrically connected to the lower surface ground conductor 22 through a plurality of plated-through holes PTH.
　図１において、チップアンテナ１０１の放射電極１１は誘電体基体１０の左後方端面に延在していて、放射電極１１の第１端（誘電体基体１０の左後方端面の下端）は基板２０１の上面グランド導体２１に接続（接地）されている。放射電極１１の第２端１１Ｓと給電電極１２との間には間隙ＧＡ１が形成されている。この間隙ＧＡ１で放射電極１１と給電電極１２との間に容量が生じる。すなわち放射電極１１は給電電極１２を介して容量給電される。接地電極１３の第１端は基板２０１の上面グランド導体２１に接続されている。接地電極１３と放射電極１１との間には間隙ＧＡ２が形成されている。この間隙ＧＡ２で放射電極１１と接地電極１３との間に容量が生じる。すなわち間隙ＧＡ２によって放射電極１１と接地との間の容量が定められている。誘電体基体１０の下面には上面の放射電極１１と対向する放射電極対向電極が形成されている。 In FIG. 1, the radiation electrode 11 of the chip antenna 101 extends to the left rear end face of the dielectric substrate 10, and the first end of the radiation electrode 11 (the lower end of the left rear end face of the dielectric substrate 10) is the substrate 201. Connected (grounded) to the upper surface ground conductor 21. A gap GA <b> 1 is formed between the second end 11 </ b> S of the radiation electrode 11 and the power supply electrode 12. A capacitance is generated between the radiation electrode 11 and the feeding electrode 12 in the gap GA1. That is, the radiation electrode 11 is capacitively fed via the feeding electrode 12. A first end of the ground electrode 13 is connected to the upper surface ground conductor 21 of the substrate 201. A gap GA <b> 2 is formed between the ground electrode 13 and the radiation electrode 11. A capacitance is generated between the radiation electrode 11 and the ground electrode 13 in the gap GA2. That is, the capacitance between the radiation electrode 11 and the ground is determined by the gap GA2. On the lower surface of the dielectric substrate 10, a radiation electrode counter electrode facing the radiation electrode 11 on the upper surface is formed.
　チップアンテナ１０１の給電電極１２は給電電極接続端子２５に接続されている。接地電極１３は接地電極接続端子２６に接続されている。チップアンテナ１０１の下面に形成されている裏面電極は接続電極に接続されている。接続端子２９は、この接続電極から引き出されている。 The feed electrode 12 of the chip antenna 101 is connected to the feed electrode connection terminal 25. The ground electrode 13 is connected to the ground electrode connection terminal 26. The back electrode formed on the lower surface of the chip antenna 101 is connected to the connection electrode. The connection terminal 29 is drawn from this connection electrode.
　給電端子２３と給電電極接続端子２５との間を接続する給電線路２４の途中と上面グランド導体２１との間には整合用素子３１が接続されている。また、裏面電極の接続端子２９と上面グランド導体２１との間には特性調整用素子３２が接続されている。 A matching element 31 is connected between the power supply line 24 connecting the power supply terminal 23 and the power supply electrode connection terminal 25 and the upper surface ground conductor 21. A characteristic adjusting element 32 is connected between the connection terminal 29 of the back electrode and the upper surface ground conductor 21.
　図３（Ａ）はアンテナ装置３０１の部分平面図、図３（Ｂ）はチップアンテナ１０１、整合用素子３１および特性調整用素子３２を実装する前の状態での基板上の導体パターンを示す平面図である。図３（Ｂ）において二点鎖線はチップアンテナ１０１の実装面に対向する範囲を表している。この範囲に接続電極２８、給電電極接続端子２５、接地電極接続端子２６、放射電極接地端の接続端子２７ａ，２７ｂが形成されている。 3A is a partial plan view of the antenna device 301, and FIG. 3B is a plan view showing a conductor pattern on the substrate before the chip antenna 101, the matching element 31 and the characteristic adjustment element 32 are mounted. FIG. In FIG. 3B, a two-dot chain line represents a range facing the mounting surface of the chip antenna 101. In this range, the connection electrode 28, the feeding electrode connection terminal 25, the ground electrode connection terminal 26, and the connection terminals 27a and 27b of the radiation electrode ground end are formed.
　整合用素子３１は例えばチップインダクタまたはチップキャパシタであり、給電端子２３に接続される給電回路のインピーダンスとチップアンテナ１０１とのインピーダンスとを整合させる。給電端子２３は各図において簡略的に表示している。給電端子２３には給電回路が接続される。 The matching element 31 is, for example, a chip inductor or a chip capacitor, and matches the impedance of the power feeding circuit connected to the power feeding terminal 23 with the impedance of the chip antenna 101. The power supply terminal 23 is simply shown in each figure. A power feeding circuit is connected to the power feeding terminal 23.
　特性調整用素子３２は、裏面電極の接続電極２８とグランド導体２１との間の容量を微調整するためのチップキャパシタである。アンテナ装置３０１の共振周波数は、チップアンテナ１０１の放射電極１１のインダクタンス、放射電極１１と裏面電極との間のキャパシタンスおよびこの特性調整用素子３２のキャパシタンスによって定まるので、特性調整用素子３２のキャパシタンスによってアンテナ装置３０１の共振周波数を定めることができる。 The characteristic adjusting element 32 is a chip capacitor for finely adjusting the capacitance between the connection electrode 28 of the back electrode and the ground conductor 21. The resonance frequency of the antenna device 301 is determined by the inductance of the radiation electrode 11 of the chip antenna 101, the capacitance between the radiation electrode 11 and the back electrode and the capacitance of the characteristic adjustment element 32. The resonance frequency of the antenna device 301 can be determined.
　図４（Ａ）、図４（Ｂ）、図４（Ｃ）は、チップアンテナの実装位置と基板の下面の導体パターンとの関係を示す図である。図４（Ａ）はチップアンテナ１０１の実装位置付近の部分平面図、図４（Ｂ）および図４（Ｃ）はチップアンテナ１０１の実装位置の裏面側の部分平面図である。図４（Ｂ）はアンテナ装置３０１について示す図、図４（Ｃ）は比較例のアンテナ装置について示す図である。図４（Ｂ）、図４（Ｃ）において二点鎖線はチップアンテナ１０１の実装面に対向する範囲を表している。このように、アンテナ装置３０１は、チップアンテナ１０１の実装面が下面グランド導体２２と対向して実装された、オングランドタイプのアンテナである。ここで“ＧＥ”は放射電極１１の接地位置（第１端）に対応する位置、“ＯＥ”は放射電極１１の容量給電位置（第２端）に対応する位置である。 4 (A), 4 (B), and 4 (C) are diagrams showing the relationship between the mounting position of the chip antenna and the conductor pattern on the lower surface of the substrate. 4A is a partial plan view in the vicinity of the mounting position of the chip antenna 101, and FIGS. 4B and 4C are partial plan views on the back side of the mounting position of the chip antenna 101. FIG. FIG. 4B is a diagram illustrating the antenna device 301, and FIG. 4C is a diagram illustrating the antenna device of the comparative example. 4B and 4C, a two-dot chain line represents a range facing the mounting surface of the chip antenna 101. As described above, the antenna device 301 is an on-ground type antenna in which the mounting surface of the chip antenna 101 is mounted to face the lower surface ground conductor 22. Here, “GE” is a position corresponding to the grounding position (first end) of the radiation electrode 11, and “OE” is a position corresponding to the capacity feeding position (second end) of the radiation electrode 11.
　図４（Ｂ）および図４（Ｃ）に表れているように、下面グランド導体２２には、チップアンテナ１０１の実装面に対向する範囲内にスリットＳＬが形成されている。スリットＳＬは下面グランド導体２２が形成されていない部分である。スリットＳＬの一端は下面グランド導体２２の端縁２２Ｅで開放されている。スリットＳＬは下面グランド導体２２の端縁２２Ｅから内側へ放射電極１１の延びる方向に対する直交方向に寸法Ｄだけ延びている。 As shown in FIGS. 4B and 4C, the lower surface ground conductor 22 has a slit SL formed in a range facing the mounting surface of the chip antenna 101. The slit SL is a portion where the lower surface ground conductor 22 is not formed. One end of the slit SL is opened at the edge 22E of the lower surface ground conductor 22. The slit SL extends from the edge 22E of the lower surface ground conductor 22 inward by a dimension D in a direction orthogonal to the direction in which the radiation electrode 11 extends.
　図４（Ｂ）に示すスリットＳＬは、放射電極１１の接地位置に対応する位置ＧＥから容量給電位置に対応する位置ＯＥまでの範囲内の容量給電位置ＯＥ寄りに形成されている。図４（Ｃ）に示すスリットＳＬは、前記範囲内の接地位置に対応する位置ＧＥ寄りに形成されている。 The slit SL shown in FIG. 4B is formed near the capacitive power supply position OE within the range from the position GE corresponding to the grounding position of the radiation electrode 11 to the position OE corresponding to the capacitive power supply position. The slit SL shown in FIG. 4C is formed near the position GE corresponding to the ground contact position within the above range.
　図５はチップアンテナ１０１およびその実装位置付近の電界強度の分布を示す斜視図である。電界の強度を濃度で表している。図５に表れているように、放射電極１１の第２端１１Ｓを中心としてその周囲に強い電界が生じる。 FIG. 5 is a perspective view showing the distribution of electric field strength near the chip antenna 101 and its mounting position. The intensity of the electric field is expressed by concentration. As shown in FIG. 5, a strong electric field is generated around the second end 11 </ b> S of the radiation electrode 11.
　図６（Ａ）、図６（Ｂ）はスリットの位置が異なる二つのアンテナ装置について、電界強度の分布を示す正面図である。図６（Ａ）は図４（Ｂ）に示した位置にスリットＳＬが形成されたアンテナ装置３０１Ａ、すなわち電界強度の高い容量給電側の対向位置にスリットＳＬが形成されたアンテナ装置の電界強度を表している。図６（Ｂ）は図４（Ｃ）に示した位置にスリットＳＬが形成されたアンテナ装置３０１Ｂ、すなわち電界強度の低い側の対向位置にスリットＳＬが形成されたアンテナ装置の電界強度を表している。いずれも電界の強度を濃度で表している。 6 (A) and 6 (B) are front views showing electric field intensity distributions for two antenna devices having different slit positions. 6A shows the electric field strength of the antenna device 301A in which the slit SL is formed at the position shown in FIG. 4B, that is, the antenna device in which the slit SL is formed at the opposite position on the capacitive feeding side where electric field strength is high. Represents. FIG. 6B shows the electric field strength of the antenna device 301B in which the slit SL is formed at the position shown in FIG. 4C, that is, the antenna device in which the slit SL is formed at the opposite position on the low electric field strength side. Yes. In either case, the intensity of the electric field is expressed as a concentration.
　図６（Ａ）と図６（Ｂ）を対比すれば明らかなように、電界強度の高い容量給電側の対向位置にスリットＳＬが形成されたアンテナ装置３０１Ａでは、スリットＳＬから電界が基板２０１の下面側へ漏れ出す。そのため基板の下面グランド導体２２に誘起される電流量が増え、基板からの放射量が増加する。この作用によってもアンテナ効率（放射能力）が向上する。 6A and 6B, in the antenna device 301A in which the slit SL is formed at the opposite position on the capacitive power feeding side where the electric field strength is high, the electric field is applied to the substrate 201 from the slit SL. Leak to the bottom side. Therefore, the amount of current induced in the lower surface ground conductor 22 of the substrate increases, and the amount of radiation from the substrate increases. This effect also improves the antenna efficiency (radiation capability).
　なお、基板に形成されているグランド導体は他の電子部品や回路との干渉を防止するシールド導体としても作用するが、前記スリットＳＬはグランド導体をスリット状に開口するものであるので、すなわちグランド導体形成領域のうちグランド導体の開口面積は小さいので、グランド導体のシールド効果は殆ど低下しない。 Although the ground conductor formed on the substrate also acts as a shield conductor that prevents interference with other electronic components and circuits, the slit SL opens the ground conductor in a slit shape, that is, the ground conductor Since the opening area of the ground conductor is small in the conductor forming region, the shielding effect of the ground conductor is hardly lowered.
　図７（Ａ）、図７（Ｂ）は下面グランド導体２２に流れる電流を示す図であり、特にチップアンテナ１０１の実装面に対向する位置付近に流れる電流について示している。図７（Ａ）はアンテナ装置３０１について示す図、図７（Ｂ）は比較例のアンテナ装置について示す図である。 7 (A) and 7 (B) are diagrams showing the current flowing through the lower surface ground conductor 22, and particularly showing the current flowing near the position facing the mounting surface of the chip antenna 101. FIG. 7A illustrates the antenna device 301, and FIG. 7B illustrates the antenna device of the comparative example.
　スリットＳＬが無い場合、図７（Ｂ）に示すように、チップアンテナ１０１の放射電極に電流ＥＣｆが流れるとき、基板の下面グランド導体２２に逆相電流ＥＣｒが誘起される。換言すると、チップアンテナ１０１の容量給電部（電界結合部）の周辺は、電界強度が非常に高く、この電界により基板の下面グランド導体２２に、放射電極に流れる電流とは逆相の電流が誘起される。そのため、放射電極による電磁界放射がグランド導体による電磁界放射で打ち消される傾向となる。 When there is no slit SL, as shown in FIG. 7B, when the current ECf flows through the radiation electrode of the chip antenna 101, a reverse phase current ECr is induced in the lower surface ground conductor 22 of the substrate. In other words, the electric field strength is very high in the vicinity of the capacitive power feeding portion (electric field coupling portion) of the chip antenna 101, and this electric field induces a current having a phase opposite to the current flowing through the radiation electrode in the lower surface ground conductor 22 of the substrate. Is done. Therefore, the electromagnetic field radiation by the radiation electrode tends to be canceled by the electromagnetic field radiation by the ground conductor.
　スリットＳＬが形成されている場合は、図７（Ａ）に示すように、チップアンテナ１０１の放射電極に電流ＥＣｆが流れるとき、基板の下面グランド導体２２に電流ＥＣｒが誘起されるが、その電流ＥＣｒはスリットＳＬで抑制される。 In the case where the slit SL is formed, as shown in FIG. 7A, when the current ECf flows through the radiation electrode of the chip antenna 101, the current ECr is induced in the lower surface ground conductor 22 of the substrate. ECr is suppressed by the slit SL.
　このように、グランド導体形成領域のうちチップアンテナ１０１の実装面に対向する範囲内にスリットＳＬが形成されていることで、逆相電流による打ち消し作用を緩和でき、結果としてアンテナ効率が改善される。 As described above, since the slit SL is formed in the range of the ground conductor formation region facing the mounting surface of the chip antenna 101, the canceling action due to the reverse phase current can be reduced, and as a result, the antenna efficiency is improved. .
　スリットＳＬは、チップアンテナ１０１の放射電極の延びる方向に対して直交方向に延びているので、スリット長Ｄの短いスリットでもグランド導体２２に流れようとする逆相電流を効果的に抑制できる。 Since the slit SL extends in a direction orthogonal to the direction in which the radiation electrode of the chip antenna 101 extends, a negative phase current that tends to flow to the ground conductor 22 even with a slit having a short slit length D can be effectively suppressed.
　なお、スリットＳＬの有無および形成位置によって、グランド導体のインダクタンスが変化し、アンテナ装置の共振周波数が僅かながら変化するので、このスリットを形成することによる共振周波数のずれを前記特性調整用素子３２のキャパシタンスによって微調整してもよい。 The inductance of the ground conductor changes depending on the presence / absence of the slit SL and the formation position, and the resonance frequency of the antenna device changes slightly. Therefore, the resonance frequency shift caused by the formation of the slit can be reduced. Fine adjustment may be made by capacitance.
　図８は前記スリットＳＬの位置や長さを変化させた場合のアンテナ効率の変化を示す図である。ここでは、スリットＳＬの無い場合を基準として、スリット長Ｄに対するアンテナ効率の改善量をプロットしている。チップアンテナ１０１の実装面の寸法は３．０×９．８ｍｍであり、高さ寸法は３．０ｍｍである。また基板２０１の厚み寸法は１．０ｍｍである。アンテナ装置３０１Ａは図４（Ｂ）に示したとおり、電界強度の高い容量給電側の対向位置にスリットＳＬが形成されたアンテナ装置である。アンテナ装置３０１Ｂは図４（Ｃ）に示したとおり、電界強度の低い側の位置にスリットＳＬが形成されたアンテナ装置である。 FIG. 8 is a diagram showing changes in antenna efficiency when the position and length of the slit SL are changed. Here, the improvement amount of the antenna efficiency with respect to the slit length D is plotted on the basis of the case where there is no slit SL. The dimension of the mounting surface of the chip antenna 101 is 3.0 × 9.8 mm, and the height dimension is 3.0 mm. The thickness dimension of the substrate 201 is 1.0 mm. As shown in FIG. 4B, the antenna device 301A is an antenna device in which slits SL are formed at opposing positions on the capacitive power feeding side where electric field strength is high. As shown in FIG. 4C, the antenna device 301B is an antenna device in which a slit SL is formed at a position where the electric field strength is low.
　アンテナ装置３０１Ａ（電界強度の高い容量給電側の対向位置にスリットＳＬが形成されたアンテナ装置）は、アンテナ装置３０１Ｂ（電界強度の低い側の位置にスリットＳＬが形成されたアンテナ装置）に比べてアンテナ効率の改善量が大きいことが分かる。また、アンテナ装置３０１Ｂの場合、アンテナ効率の改善量はスリット長Ｄの変化によっては殆ど変化がないが、アンテナ装置３０１Ａではスリット長Ｄが長くなるほどアンテナ効率の改善量は大きくなる。このことから、スリット長Ｄが長くなることに伴い、スリットＳＬからの電界の漏れによる放射量が大きくなって、アンテナ効率が改善されることが分かる。 The antenna device 301A (antenna device in which the slit SL is formed at a position opposite to the capacitive power feeding side with high electric field strength) is compared with the antenna device 301B (antenna device in which the slit SL is formed in a position on the low electric field strength side). It can be seen that the improvement in antenna efficiency is large. In the case of the antenna device 301B, the improvement amount of the antenna efficiency hardly changes depending on the change of the slit length D, but in the antenna device 301A, the improvement amount of the antenna efficiency becomes larger as the slit length D becomes longer. From this, it can be seen that as the slit length D increases, the radiation amount due to leakage of the electric field from the slit SL increases, and the antenna efficiency is improved.
　なお、チップアンテナの放射電極に流れる電流によって基板のグランド導体に誘起される電流は、放射電極とグランド導体とが離れているほど小さくなるので、チップアンテナの誘電体基体の高さ寸法を大きくするとともに、この誘電体基体の上面に放射電極を形成することはアンテナ効率の向上のために有効であるが、本発明によれば、チップアンテナを高くしなくても前記「逆相電流による打ち消し作用」が抑制されるので、その分チップアンテナを低背化できる。 Note that the current induced in the ground conductor of the substrate by the current flowing through the radiation electrode of the chip antenna decreases as the distance between the radiation electrode and the ground conductor decreases, so the height dimension of the dielectric substrate of the chip antenna is increased. At the same time, forming the radiation electrode on the upper surface of the dielectric substrate is effective for improving the antenna efficiency. However, according to the present invention, the “cancellation effect due to the reverse phase current” can be achieved without increasing the chip antenna. "Is suppressed, the chip antenna can be reduced in height accordingly.
　図９、図１０は以上に示したアンテナ装置とは異なるアンテナ装置における基板の部分下面図である。基板の上面の構成および基板の上面に実装されるチップアンテナの構成は図１等に示したものと同じである。 9 and 10 are partial bottom views of a substrate in an antenna device different from the antenna device shown above. The configuration of the upper surface of the substrate and the configuration of the chip antenna mounted on the upper surface of the substrate are the same as those shown in FIG.
　図９に示す例では、スリットＳＬがＴ字状である。この形状であっても、スリットＳＬからの電界の漏れ出し作用および逆相電流の抑制作用があるので、アンテナ効率が向上する。このようにスリットは必ずしも一つの方向に延びる形状である必要はなく、複数の方向に延びる部分を備えていてもよい。 In the example shown in FIG. 9, the slit SL is T-shaped. Even in this shape, the antenna efficiency is improved because of the leakage action of the electric field from the slit SL and the suppression action of the reverse phase current. Thus, the slit does not necessarily have a shape extending in one direction, and may include a portion extending in a plurality of directions.
　図１０に示す例では、スリットＳＬがチップアンテナの放射電極の延びる方向に対して傾斜している。この形状であっても、スリットＳＬは放射電極の延びる方向に対し非平行であるので、スリットＳＬからの電界の漏れ出し作用および逆相電流の抑制作用がある。したがってアンテナ効率が向上する。このようにスリットの延びる方向は放射電極の延びる方向に対して必ずしも直交している必要はなく、傾斜していてもよい。 In the example shown in FIG. 10, the slit SL is inclined with respect to the extending direction of the radiation electrode of the chip antenna. Even in this shape, the slit SL is non-parallel to the direction in which the radiation electrode extends, and thus has an action of leaking an electric field from the slit SL and an action of suppressing a reverse phase current. Therefore, antenna efficiency is improved. Thus, the direction in which the slit extends does not necessarily have to be orthogonal to the direction in which the radiation electrode extends, and may be inclined.
　また、図４（Ａ）、図４（Ｂ）、図９、図１０に示した例では、スリットＳＬが放射電極１１の接地位置に対応する位置ＧＥから容量給電位置に対応する位置ＯＥまでの範囲内に形成されているが、この範囲からはみ出ていてもよい。 In the example shown in FIGS. 4A, 4B, 9, and 10, the slit SL extends from the position GE corresponding to the grounding position of the radiation electrode 11 to the position OE corresponding to the capacitive power supply position. Although it is formed within the range, it may protrude from this range.
　なお、スリットは電界強度の高いところに形成すると電界放射効果が高まるが、必ずしも電界強度の最も高い位置に形成されていなくてもよい。図４（Ｃ）および図８に示したように、グランド導体の形成領域のうち、チップアンテナの実装面に対向する範囲内で、容量給電位置に対応する位置より接地位置に対応する位置寄りに形成されていてもアンテナ効率の改善効果はある。 Note that, when the slit is formed at a place where the electric field strength is high, the field emission effect is enhanced, but it is not necessarily formed at the position where the electric field strength is the highest. As shown in FIGS. 4C and 8, the ground conductor forming region is closer to the position corresponding to the grounding position than the position corresponding to the capacitive power feeding position within the range facing the mounting surface of the chip antenna. Even if formed, the antenna efficiency can be improved.
　また、チップアンテナの実装面の全面が基板のグランド導体と対向して実装されたオングランドタイプのアンテナに限らず、チップアンテナの実装面の一部が基板のグランド導体と対向して実装されたアンテナ装置についても、基板のグランド導体に電流が誘起されるので、同様に適用できる。 In addition, the mounting surface of the chip antenna is not limited to the on-ground type antenna that is mounted facing the ground conductor of the substrate, but a part of the mounting surface of the chip antenna is mounted facing the ground conductor of the substrate. The antenna device can be similarly applied because an electric current is induced in the ground conductor of the substrate.
Ｄ…スリット長
ＥＣｆ…電流
ＥＣｒ…逆相電流
ＧＡ１，ＧＡ２…間隙
ＧＥ…接地位置対応位置
ＯＥ…容量給電位置対応位置
ＳＬ…スリット
１０…誘電体基体
１１…放射電極
１１Ｓ…第２端
１２…給電電極
１３…接地電極
２０…基材
２１…上面グランド導体
２２…下面グランド導体
２２Ｅ…端縁
２３…給電端子
２４…給電線路
２５…給電電極接続端子
２６…接地電極接続端子
２７ａ，２７ｂ…接続端子
２８…接続電極
２９…接続端子
３１…整合用素子
３２…特性調整用素子
１０１…チップアンテナ
２０１…基板
３０１…アンテナ装置 D ... slit length ECf ... current ECr ... reverse phase current GA1, GA2 ... gap GE ... grounding position corresponding position OE ... capacitance feeding position corresponding position SL ... slit 10 ... dielectric substrate 11 ... radiation electrode 11S ... second end 12 ... power supply Electrode 13 ... Ground electrode 20 ... Base material 21 ... Upper surface ground conductor 22 ... Lower surface ground conductor 22E ... Edge 23 ... Feed terminal 24 ... Feed line 25 ... Feed electrode connection terminal 26 ... Ground electrode connection terminals 27a, 27b ... Connection terminal 28 ... Connection electrode 29 ... Connection terminal 31 ... Matching element 32 ... Characteristic adjustment element 101 ... Chip antenna 201 ... Substrate 301 ... Antenna device

Claims (3)

  1. 　誘電体基体およびこの誘電体基体に形成された放射電極を含んで構成されるチップアンテナと、基材およびこの基材に形成されたグランド導体を含んで構成される基板と、を備え、前記基板に前記チップアンテナが実装されて構成されたアンテナ装置において、
    　前記放射電極は第１端が前記グランド導体に接地され、且つ第２端から容量給電され、
    　前記グランド導体の形成領域のうち前記チップアンテナの実装面に対向する範囲内にスリットが形成されたことを特徴とするアンテナ装置。     A chip antenna comprising a dielectric substrate and a radiation electrode formed on the dielectric substrate; and a substrate comprising a substrate and a ground conductor formed on the substrate, the substrate In the antenna device configured with the chip antenna mounted thereon,
    The radiation electrode has a first end grounded to the ground conductor and a capacitive power supply from a second end,
    An antenna device, wherein a slit is formed in a range facing the mounting surface of the chip antenna in a formation region of the ground conductor.
  2. 　前記スリットは、前記グランド導体の形成領域のうち前記チップアンテナの実装面に対向する範囲内で、前記第１端よりも前記第２端寄りの位置に形成されている、請求項１に記載のアンテナ装置。 2. The slit according to claim 1, wherein the slit is formed at a position closer to the second end than the first end within a range facing the mounting surface of the chip antenna in a formation region of the ground conductor. Antenna device.
  3. 　前記スリットは前記放射電極の延びる方向に対し直交方向に延びる、請求項１または２に記載のアンテナ装置。 The antenna device according to claim 1 or 2, wherein the slit extends in a direction orthogonal to a direction in which the radiation electrode extends.
PCT/JP2013/067180 2012-07-04 2013-06-24 Antenna apparatus WO2014007087A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2012150488 2012-07-04
JP2012-150488 2012-07-04

Publications (1)

Publication Number Publication Date
WO2014007087A1 true WO2014007087A1 (en) 2014-01-09

Family

ID=49881845

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2013/067180 WO2014007087A1 (en) 2012-07-04 2013-06-24 Antenna apparatus

Country Status (1)

Country Link
WO (1) WO2014007087A1 (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003347835A (en) * 2002-05-24 2003-12-05 Murata Mfg Co Ltd Antenna structure and communication device provided with the same
WO2006120763A1 (en) * 2005-05-13 2006-11-16 Murata Manufacturing Co., Ltd. Antenna structure and radio communication device using the same

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003347835A (en) * 2002-05-24 2003-12-05 Murata Mfg Co Ltd Antenna structure and communication device provided with the same
WO2006120763A1 (en) * 2005-05-13 2006-11-16 Murata Manufacturing Co., Ltd. Antenna structure and radio communication device using the same

Similar Documents

Publication Publication Date Title
US10062956B2 (en) Antenna device and electronic apparatus
US8379408B2 (en) Electromagnetic shield structure, wireless device using the structure, and method of manufacturing electromagnetic shield
US10236579B2 (en) Dual-band dual-port antenna structure
US8525732B2 (en) Antenna device
US9698481B2 (en) Chip antenna and communication circuit substrate for transmission and reception
JP6187606B2 (en) Printed board
JP6015944B2 (en) ANTENNA DEVICE, COMMUNICATION DEVICE, AND ELECTRONIC DEVICE
US9142884B2 (en) Antenna device
JP2008311688A (en) Chip antenna
JP5403059B2 (en) Flexible substrate antenna and antenna device
US10811774B2 (en) Loop antenna
JP2008300897A (en) Antenna unit
JP5035323B2 (en) antenna
TWI765599B (en) Electronic device and antenna structure
JP2013211797A (en) Communication terminal
JP2009290687A (en) Antenna device and radio communication device
CN106465551B (en) The noise reducing method of circuit substrate and circuit substrate
US20090237309A1 (en) Radio apparatus and antenna device including anisotropic dielectric material
JPWO2012160947A1 (en) Antenna device and communication terminal device
WO2014007087A1 (en) Antenna apparatus
JP5958820B2 (en) Antenna device
JP2012104895A (en) Sliding wireless terminal
CN107658556B (en) Wireless communication device
JP5995059B2 (en) Antenna device
JP2015142224A (en) Antenna device and electronic apparatus

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 13813316

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13813316

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP