WO2010107137A1

WO2010107137A1 - Chip antenna

Info

Publication number: WO2010107137A1
Application number: PCT/JP2010/055478
Authority: WO
Inventors: 淳伊藤; 祐一馬場
Original assignee: カンタツ株式会社
Priority date: 2009-03-19
Filing date: 2010-03-19
Publication date: 2010-09-23
Also published as: TW201042818A

Abstract

A chip antenna able to reliably transmit and receive a GHz band radio wave having high straight-line propagation properties. In the chip antenna (10), which is comprised of an antenna element (12) formed around a prism-shaped base (11) but not on the ends of the base (11), the ridge parts of the base (11) on which the antenna element (12) is formed have curved shapes. Further, the antenna element (12) is formed in a meandering state along the longitudinal direction of the base (11), and the bent angular parts are formed in a smooth curved shape. Due to this, the straight-line propagation properties of the antenna element (12) are improved and the 1.5 Ghz band and 2.4 Ghz band radio waves with high straight-line propagation properties are more inclined to resonate. As a result, 1.5 GHz band and 2.4 GHz band radio waves can be reliably transmitted and received.

Description

Chip antenna

The present invention relates to a chip antenna suitable for mobile devices such as mobile phones and PDAs (Personal Digital Assistants), personal computers compatible with wireless LAN (Local Area Network), game devices, and home appliances.

As an antenna incorporated in a cellular phone or the like, a chip antenna that replaces a rod antenna or a helical coil antenna has been generally known (see, for example, Patent Documents 1 to 3). In this type of chip antenna, an antenna element made of a silver alloy or the like and a feeding portion are formed in an appropriate pattern on the surface of a base made of dielectric plastics having a high dielectric constant. It has the characteristic of being.
Here, Patent Document 1 describes a chip antenna in which a plurality of inverted L-shaped antenna elements are formed to face both side surfaces of a base. Patent Document 2 describes a chip antenna in which an inverted L-shaped antenna element is formed across a peripheral surface except for both end surfaces of a base. Further, Patent Document 3 describes a chip antenna in which antenna elements are formed in a meandering manner on the upper surface of a base.

JP 2007-166297 A Japanese Patent Laid-Open No. 2002-50918 JP 2002-124812 A

In recent years, this type of chip antenna has been requested to be able to reliably transmit and receive radio waves in the GHz band. However, it is difficult to reliably transmit and receive these radio waves because the radio waves in the GHz band are extremely straight. In this regard, in the chip antennas described in Patent Documents 1 to 3 described above, there is actually no special means for reliably transmitting and receiving radio waves in the GHz band with extremely high straightness.
Therefore, an object of the present invention is to provide a chip antenna that can reliably transmit and receive radio waves in the GHz band with high straightness.

In order to solve such a problem, a chip antenna according to the present invention is a chip antenna in which an antenna element is formed on a surface of a prismatic base, and the antenna element is a peripheral surface excluding both end faces of the base, or It is formed in the surrounding surface except a both-sides surface, The ridgeline part in which an antenna element is formed is formed in the curved surface shape among the ridgeline parts of a base | substrate.
In the chip antenna according to the present invention, since the ridge line portion of the base on which the antenna element is formed is formed in a curved surface, the straightness of the antenna element is improved, and the GHz band radio wave having high straightness is likely to resonate. .
Here, in the chip antenna in which the antenna element is formed on the peripheral surface excluding the both end surfaces of the base body, a base array in which a plurality of base bodies are continuous in the longitudinal direction is manufactured. A plurality of chip antennas can be manufactured by forming a plurality of antenna elements corresponding to the substrate and then cutting the substrate array in the longitudinal direction to divide the substrate into a plurality of substrates.
Similarly, in the chip antenna in which the antenna element is formed on the peripheral surface excluding both side surfaces of the base body, a base array in which a plurality of base bodies are continuous in the width direction is manufactured. A plurality of chip antennas can be manufactured by forming a plurality of antenna elements corresponding to the substrate and then cutting the substrate array in the width direction to divide the substrate into a plurality of substrates.
In the chip antenna of the present invention, the antenna element can be formed in a meandering state along the longitudinal direction of the substrate. In this case, in order to improve the straightness of the antenna element, it is preferable that the bent portion of the antenna element is formed in a curved shape.
In the chip antenna of the present invention, the substrate is preferably made of dielectric plastics having a dielectric constant ε of 3 to 20. In this case, the wavelength shortening rate due to the base is increased, so that the chip antenna can be further miniaturized.

According to the chip antenna according to the present invention, since the ridge portion of the base on which the antenna element is formed is formed in a curved surface, the straightness of the antenna element is improved, and the radio wave in the GHz band with high straightness resonates. It becomes easy. As a result, it is possible to reliably transmit and receive GHz band radio waves.
In the chip antenna according to the present invention, when the antenna element is formed on the peripheral surface excluding both end faces of the substrate, a substrate array in which a plurality of substrates are continuous in the longitudinal direction is manufactured. A plurality of chip antennas can be easily manufactured by forming a plurality of antenna elements corresponding to each substrate on the peripheral surface and then cutting the substrate array in the longitudinal direction to divide the substrate into a plurality of substrates.
Further, in the chip antenna according to the present invention, when the antenna element is formed on the peripheral surface excluding both side surfaces of the base body, a base array in which a plurality of base bodies are continuous in the width direction is manufactured. After forming a plurality of antenna elements corresponding to each substrate on the peripheral surface of the array, the substrate array is cut in the width direction and divided into a plurality of substrates, whereby a plurality of chip antennas can be easily manufactured.
Furthermore, in the chip antenna of the present invention, when the base is made of dielectric plastics having a dielectric constant ε of 3 to 20, the speed of the radio wave passing through the base is greatly reduced, and the antenna element is correspondingly reduced. Since the wavelength of the radio wave transmitted and received by is greatly reduced, the chip antenna can be further miniaturized.

FIG. 1 is a perspective view showing an upper surface and a right side surface of a chip antenna according to a first embodiment of the present invention when viewed from one end side in a longitudinal direction.
FIG. 2 is a perspective view showing an upper surface and a left side surface of the chip antenna as viewed from one end side in the longitudinal direction.
FIG. 3 is a perspective view showing the lower surface and the right side surface of the chip antenna as viewed from the other end side in the longitudinal direction.
FIG. 4 is a perspective view showing the lower surface and the left side surface of the chip antenna as viewed from the other end side in the longitudinal direction.
FIG. 5 is a graph showing the relationship between the reception frequency and return loss of the chip antenna.
FIG. 6 is a perspective view of a base array used for manufacturing the chip antenna.
FIG. 7 is a perspective view showing the top surface and the right side surface of the chip antenna according to the second embodiment when viewed from one end side in the longitudinal direction.
FIG. 8 is a perspective view of a base array used for manufacturing the chip antenna.
FIG. 9 is a perspective view showing the top surface and the right side surface of the chip antenna according to the third embodiment when viewed from one end side in the longitudinal direction.
FIG. 10 is a perspective view showing the lower surface and the right side surface of the chip antenna as viewed from the other end side in the longitudinal direction.
FIG. 11 is a perspective view showing the top surface and the right side surface of the chip antenna according to the fourth embodiment when viewed from one end side in the longitudinal direction.
FIG. 12 is a perspective view showing the top surface and the right side surface of the chip antenna according to the fifth embodiment when viewed from one end side in the longitudinal direction.

Hereinafter, a first embodiment of a chip antenna according to the present invention will be described with reference to FIGS. A chip antenna 10 according to the first embodiment is a small and high-performance antenna that can be incorporated into a mobile device such as a next-generation mobile phone, and is a monopole having resonance frequencies in, for example, 1.5 GHz band and 2.4 GHz band. Functions as an antenna.
As shown in FIGS. 1 to 4, the chip antenna 10 of the first embodiment includes a base body 11 made of dielectric plastics formed in a prismatic shape having a length of 15 mm, a width of 3.5 mm, and a thickness of about 3.0 mm. It has. On the peripheral surface excluding both

end faces

11A and 11B of the base 11, an antenna element 12 constituting a monopole antenna, a power feeding unit 13 for feeding power to the antenna element 12, and a chip on a mounting board (not shown) For example, three land portions 14 for fixing the antenna 10 are formed.
The dielectric plastics constituting the substrate 11 is made of a composite material compounded with ceramics having a high dielectric constant, polyphenylene sulfide resin (PPS), and liquid crystal polymer (LCP), and has dimensional stability and solder suitable for precision molding. And a high dielectric property with a dielectric constant ε in the range of 3-20. Then, shot blasting is performed on the peripheral surface of the base body 11 excluding both

end faces

11A and 11B as a base treatment for forming the antenna element 12.
The antenna element 12, the feeding portion 13, and the three land portions 14 are formed by patterning a plating layer made of an appropriate conductive metal material such as copper, nickel, silver alloy or the like into a predetermined shape.
The antenna element 12 corresponds to, for example, a 1.5 GHz band GPS and a 2.4 GHz band W-LAN, and the wavelength is shortened according to the dielectric constant ε of the substrate 11. The antenna element 12 is formed in a meandering state along the longitudinal direction of the base 11 across the right side, the top, and the left side of the base 11 excluding both

end faces

11A and 11B.
The antenna element 12 includes a base-side straight portion 12A extending in a band shape from the one end surface 11A side to the other end surface 11B side on the upper right side of the base body 11, and a central portion of the upper surface of the base body 11 from the other end face 11B side. It has a strip-shaped intermediate straight portion 12B that is folded back toward the end surface 11A side, and a strip-shaped front-end-side straight portion 12C that is folded back from the one end surface 11A side toward the other end surface 11B side.
The antenna element 12 includes a base-end side bent portion 12D that is bent so that the base-end side straight portion 12A is continuous with the power feeding portion 13 (see FIG. 3) on the one end surface 11A side of the base 11, and the base 11 An intermediate bent portion 12E that bends so that the proximal end straight portion 12A and the intermediate straight portion 12B are continuous on the other end face 11B side, and an intermediate straight portion 12B and a distal end straight portion 12C on the one end face 11A side of the base body 11. And a distal end side bent portion 12F which is bent so as to be continuous.
Here, among the ridge line portions of the base body 11, the ridge line portion where the antenna element 12 is formed, that is, the upper surface and the right side surface of the base body 11, so as to ensure the straightness of the antenna element 12 and improve the high frequency characteristics. The ridge line portion between them and the ridge line portion between the upper surface and the left side surface are not formed in a right angle but are formed in a curved surface shape of about 0.5 to 0.8R.
Further, in order to secure the straightness of the antenna element 12 and further improve the high frequency characteristics, the bent corners of the base end side bent portion 12D, the intermediate bent portion 12E, and the distal end side bent portion 12F of the antenna element 12 are , It is not a right angle but a smooth curved line.
As shown in FIGS. 3 and 4, the power feeding portion 13 that feeds power to the antenna element 12 is formed on the right side portion of the lower surface of the one end portion 11 </ b> A of the base body 11, and the proximal end side bent portion 12 </ b> D of the antenna element 12. It is continuous. Further, the three land portions 14 for fixing the chip antenna 10 on a mounting substrate (not shown) are formed at the other three corner portions excluding the portion where the power feeding portion 13 is formed on the lower surface of the base 11.
The chip antenna 10 of the first embodiment configured as described above transmits and receives, for example, 1.5 GHz band and 2.4 GHz band radio waves by being incorporated in a mounting board of a mobile device (not shown).
Here, in the chip antenna 10 of the first embodiment, the ridge line portion of the base body 11 on which the antenna element 12 is formed, that is, the ridge line portion between the upper surface and the right side surface of the base body 11 and between the upper surface and the left side surface. The ridge portion is not a right-angled shape but is formed in a curved surface shape of about 0.5 to 0.8R. In addition, the bent corners of the base end side bent portion 12D, the intermediate bent portion 12E, and the distal end side bent portion 12F of the antenna element 12 are formed in a smooth curved line instead of a right angle.
For this reason, in the chip antenna 10 of the first embodiment, the straightness of the antenna element 12 is improved, and the relational characteristic between the reception frequency and the return loss is as shown in the graph of FIG. That is, in the chip antenna 10 according to the embodiment, 1.5 GHz band and 2.4 GHz band radio waves with high straightness are likely to resonate, and 1.5 GHz band and 2.4 GHz band radio waves can be reliably transmitted and received. It becomes possible.
Here, in manufacturing the chip antenna 10 of the first embodiment, a base array (see FIG. 6) in which a plurality of base bodies 11 are continuous in the longitudinal direction is manufactured, and each base body 11 corresponds to the peripheral surface of the base array. After the plurality of antenna elements 12 are formed, the chip array 10 can be easily manufactured by cutting the base array in the longitudinal direction and dividing the base array into the plurality of bases 11.
At this time, since the formation pattern of the antenna element 12 is a relatively simple meandering pattern, the antenna element 12 can be easily formed as compared with the antenna elements in the conventional prior art.
The chip antenna according to the present invention is not limited to the above-described first embodiment. For example, the chip antenna 20 of the second embodiment as shown in FIGS. 7 and 8 and as shown in FIGS. The chip antenna 30 of the third embodiment, the chip antenna 40 of the fourth embodiment as shown in FIG. 11, or the chip antenna 50 of the fifth embodiment as shown in FIG.
The chip antenna 20 of the second embodiment shown in FIG. 7 and FIG. 8 is such that an antenna element 22 constituting a monopole antenna is formed on the peripheral surface excluding both

side surfaces

21C and 21D of a base body 21. Is formed along the longitudinal direction from the one end surface 21A of the base 21 to the upper surface.
Here, among the ridge lines of the base 21, the ridge lines where the antenna elements 22 are formed, that is, the one end surface 21 </ b> A and the top surface of the base 21, so as to ensure the straightness of the antenna element 22 and improve the high frequency characteristics. The ridge line portion between the upper surface and the ridge line portion between the upper surface and the other end surface 21B is formed in a curved surface shape of about 0.5 to 0.8 R that is not a right angle.
Further, the corners of the antenna element 22 that are bent are formed not in a right angle but in a smooth curved shape so as to ensure the straightness of the antenna element 22 and further improve the high frequency characteristics.
Also in this chip antenna 20, 1.5 GHz band and 2.4 GHz band radio waves having high straightness are likely to resonate, and 1.5 GHz band and 2.4 GHz band radio waves can be reliably transmitted and received.
Here, in the manufacture of the chip antenna 20 of the second embodiment, a base array (see FIG. 8) in which a plurality of base bodies 21 are continuous in the width direction is manufactured, and each base body 21 corresponds to the peripheral surface of the base array. After forming the plurality of antenna elements 22, the plurality of chip antennas 20 can be easily manufactured by cutting the base array in the width direction and dividing it into the plurality of bases 21.
A chip antenna 30 according to the third embodiment shown in FIGS. 9 and 10 is configured such that an antenna element 32 constituting an inverted L-shaped antenna is formed on the peripheral surface of the base 31 excluding both end faces 31A and 31B. Among the ridge line portions, the ridge line portion where the antenna element 32 is formed, that is, the ridge line portion between the upper surface and the right side surface of the base 31 and the ridge line portion between the upper surface and the left side surface are not perpendicular. It is formed in a curved surface shape of about 5 to 0.8R.
And the corner | angular part which the antenna element 22 bends is formed in the smooth curved line shape instead of a right angle so that the rectilinear property of the antenna element 22 may be ensured and a high frequency characteristic may be improved further.
Also in this chip antenna 20, 1.5 GHz band and 2.4 GHz band radio waves having high straightness are likely to resonate, and 1.5 GHz band and 2.4 GHz band radio waves can be reliably transmitted and received.
A chip antenna 40 according to the fourth embodiment shown in FIG. 11 has an antenna element 42 constituting an inverted F-shaped antenna formed from the right side surface to the upper surface of the peripheral surface excluding both

end surfaces

41A and 41B of the base body 41. In the ridge line portion of the base body 41, the ridge line portion where the antenna element 42 is formed, that is, the ridge line portion between the upper surface and the right side surface of the base body 41 and the ridge line portion between the upper surface and the left side surface are at right angles. It is formed in a curved shape of about 0.5 to 0.8R.
Similarly, in the chip antenna 50 of the fifth embodiment shown in FIG. 12, the antenna element 52 constituting the inverted F-shaped antenna is formed from the right side surface to the upper surface of the peripheral surface excluding both

end surfaces

51A and 51B of the base body 51. Among the ridge line portions of the base 51, the ridge line portion where the antenna element 52 is formed, that is, the ridge line portion between the upper surface and the right side surface of the base body 51 and the ridge line portion between the upper surface and the left side surface are It is formed in a curved surface of about 0.5 to 0.8 R that is not a right angle.
In the chip antenna 40 shown in FIG. 11 and the chip antenna 50 shown in FIG. 12 as well, the 1.5 GHz band and 2.4 GHz band, which are highly rectilinear, easily resonate in 1.5 GHz band and 2.4 GHz band. It is possible to reliably transmit and receive radio waves.

10, 20, 30, 40, 50

Chip antenna

11, 21, 31, 41, 51 Base 11A One end 11B

Other end

12, 22, 32, 42, 52 Antenna element 12A Base end side straight portion 12B Intermediate straight portion 12C Front end side straight portion 12D Base end side bent portion 12E Intermediate bent portion 12F Front end side bent portion 13 Power feeding portion 14 Land portion

Claims

A chip antenna having an antenna element formed on the surface of a prismatic base,
The antenna element is formed on a peripheral surface excluding both end surfaces of the base, or on a peripheral surface excluding both side surfaces,
Of the ridge line portions of the substrate, the ridge line portion on which the antenna element is formed is formed in a curved surface shape.
2. The chip antenna according to claim 1, wherein the antenna element is formed in a meandering state along a longitudinal direction of the base body, and a bent corner portion thereof is formed in a curved shape.
3. The chip antenna according to claim 1, wherein the substrate is made of dielectric plastics having a dielectric constant ε of 3 to 20.