JP2008078714A - Antenna in common use for two-frequency, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna in common use for two frequencies capable of securing stable quality such as high electric characteristics. <P>SOLUTION: In the non-grounded antenna in common use for two frequencies, first and second λ<SB>1</SB>/4 antenna patterns 31 and 32 resonating at a wavelength λ<SB>1</SB>and first and second λ<SB>2</SB>/4 antenna patterns 41 and 42 resonating at a wavelength λ<SB>2</SB>are extended like approximately identical lines an insulating gap apart from each other on one surface 11 of a slender insulating substrate 1, and the first λ<SB>1</SB>/4 and λ<SB>2</SB>/4 antenna patterns 31 and 41 and the second λ<SB>1</SB>/4 and λ<SB>2</SB>/4 antenna patterns 32 and 42 are spaced from each other in an area other than lateral side parts 51 and 52, and through holes 71 and 72 are provided in this area. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a dual-frequency antenna that can be shared by radio waves in two frequency bands, and an electronic device including the dual-frequency antenna.

In recent years, wireless LANs to which two frequency bands of 2.4 GHz band and 5 GHz band are allocated, such as wireless LANs to which two frequency bands are allocated in the same wireless communication system, have been used. The antenna installed in equipment has been required to be a dual-frequency antenna that can be shared by two frequency bands. The Such dual frequency antenna, the longitudinal end to lambda _2/4 striatum antenna element of elongate substrates are formed in a linear shape conductive pattern, rectangular conducting lambda _2/4 strip-shaped antenna element to the other of thereby forming a pattern, lambda _1/4 the cylindrical antenna element so as to be disposed on the outer periphery of the lambda _2/4 striatum antenna element fitted disposed on the substrate, the lambda _2/4 strip-shaped antenna element those soldering the lambda _1/4 strip-shaped antenna element L shape input has been known (see Patent Document 1).

JP 2003-338708 A

Meanwhile, the two-frequency antenna of Patent Document 1, the lambda _2/4 insulating substrate on which the antenna element is formed, the mounting positions the cylindrical antenna element separate, yet, separate lambda _1/4 strip Since the antenna element is positioned and attached by soldering, there is a problem that the quality of the product such as electrical characteristics is easily affected by variations in the mounting operation.

  This invention is proposed in view of the said subject, Comprising: It aims at providing the dual frequency shared antenna which can ensure stable quality, such as a high electrical property, and an electronic device provided with the dual frequency shared antenna. .

A dual frequency antenna of the present invention, an antenna pattern which resonates the insulating elongate substrates at the wavelength lambda _1, is provided integrally with an antenna pattern which resonates at the wavelength lambda ₁ and wavelength different lambda _2, dual frequency of ungrounded a shared antenna, on one surface of the insulating substrate, first, second lambda _1/4 antenna patterns, and the first, second lambda _2/4 antenna pattern, spaced apart by respective insulating gap to extend substantially in the longitudinal direction in the same straight line, the first lambda _1/4 antenna pattern and the first lambda _2/4 antenna patterns, and a second lambda _1/4 antenna pattern and the second lambda _2/4 The antenna patterns are separated from each other at least in a region other than the vicinity of the insulating gap.

Further, the two-frequency antenna of the present invention, wherein the insulating substrate first lambda _1/4 antenna pattern and the separation portion of the first lambda _2/4 antenna pattern and the second lambda _1/4 antenna pattern and providing a through-hole in the spaced locations of the second lambda _2/4 antenna pattern.

Further, the two-frequency antenna of the present invention, the on the other surface of the insulating substrate, wherein by disposing a third lambda _1/4 antenna pattern on the first lambda _1/4 antenna pattern and a position substantially corresponding to connected through a conductor provided in the through-hole of the insulating substrate, the third, fourth lambda _2/4 first respective antenna patterns, and arranged on the second lambda _2/4 antenna pattern and a position substantially corresponding to The connection is made through a conductor provided in the through hole of the insulating substrate.

Further, the two-frequency antenna of the present invention, first, towards the insulation gap to the second lambda _2/4 antenna patterns provided an area for widening, so as to face the widened region, third, 4 of lambda _2/4 toward the insulating gap antenna pattern and providing a region widening. The widened area may be a gradually widened area, a stepwise widened area, or the like. Furthermore, it is also possible to have the same configuration to lambda _1/4 antenna pattern.

Further, the two-frequency antenna of the present invention, first, second lambda _1/4 antenna pattern, and the first, the coaxial line connected by the insulating gap near the second lambda _2/4 antenna pattern wherein along a substantially longitudinal direction of the insulating substrate disposed at a distance from each other in the other side, wide, overlap the coaxial line from the coaxial line to at least the tip of said first or second lambda _1/4 antenna pattern It is characterized by providing the protrusion part arrange | positioned.

  Moreover, an electronic apparatus according to the present invention includes the dual-frequency antenna.

  In the invention of the present application, the partial configuration of each invention is changed to another configuration, or another configuration is added to the configuration of each invention, or the partial configuration of each invention is partially functioned. It is also included as a superordinate concept by deleting as much as possible.

An electronic apparatus including a two-frequency antenna and the dual frequency antenna of the present invention, first, second lambda _1/4 antenna pattern and the first, the second lambda _2/4 antenna patterns on a single insulating substrate Since they are integrally provided in an appropriate arrangement, the work of attaching a separate antenna element to the insulating substrate can be eliminated. Therefore, it is possible to prevent variations in product quality during the manufacturing process, and it is possible to reliably obtain a dual-frequency antenna having stable electrical characteristics and an electronic device including the dual-frequency antenna.

Further, by providing the through-hole in the insulating substrate in spaced locations between lambda _1/4 antenna pattern and lambda _2/4 antenna pattern are arranged in parallel, increasing the impedance between the two antenna patterns with air intervening, the resonant frequency It is possible to increase the isolation between the two antenna patterns having different values.

Further, the other surface of the insulating substrate, connected by conductors provided arranged to both patterns at positions corresponding substantially with lambda _1/4 antenna pattern on one surface of lambda _1/4 antenna pattern in the through hole, lambda _2/4 by connecting a conductor of an antenna pattern is disposed in a position substantially corresponding to the lambda _2/4 antenna pattern on one surface providing both patterns in the through-hole, current to the one surface and the other surface Antenna patterns having the same distribution can be formed, and a uniform gain can be obtained in almost all directions.

The first, towards the insulation gap to the second lambda _2/4 antenna patterns provided an area for widening, so as to face the widened region across the insulating substrate, the third, fourth lambda ₂ / toward said insulating gap by providing an area for widening the 4 antenna pattern relates frequency of the wavelength lambda _2, it is possible to lower the quality factor Q, to obtain broadband characteristics.

Further, the coaxial line is disposed apart from the other surface side of the insulating substrate, and a protrusion that is wider than the coaxial line and overlaps the coaxial line is provided at the tip of the λ 1/4 antenna pattern on the _one surface. By providing, leakage current can be prevented while accommodating movement within the width of the protruding portion of the coaxial line.

  An embodiment of a dual-frequency antenna according to the present invention will be described with reference to the drawings.

As shown in FIGS. 1 to 3, the non-grounded dual-frequency antenna according to this embodiment is provided in close contact with an insulating substrate 1 that is an elongated rectangle and one surface 11 of the insulating substrate 1. a first, first, second lambda _2/4 antenna patterns 41 and 42 which resonates at the second lambda _1/4 antenna patterns 31 and 32, and short wavelength lambda ₂ than the wavelength lambda ₁ which resonates at lambda _1, third, fourth lambda _2/4 antenna which resonates provided in close contact with the other surface 12 of the insulating substrate 1, a third lambda _1/4 antenna pattern 33 which resonates at the wavelength lambda _1, and the wavelength lambda ₂ Patterns 43 and 44 are provided.

The insulating substrate 1 is formed of a glass epoxy material having a relative dielectric constant ε _r = 4.7, for example, but can be formed of an appropriate insulating material. The antenna patterns 31 to 33 and 41 to 44 are integrally formed and laminated on one surface 11 and the other surface 12 of the insulating substrate 1 by etching, and an antenna is arranged at the center in the longitudinal direction of the insulating substrate 1. A pattern is not formed, and an insulating gap 2 is provided that performs impedance adjustment and a feeding structure. Incidentally, by adjusting the width of the insulating gap 2 (length in the longitudinal direction of the insulating substrate 1), it is possible to adjust the antenna impedance in both of the two frequency bands. For example, in the 2.4 GHz band and the 5 GHz band, The width of the insulating gap 2 is preferably about 2.5 mm.

lambda _1/4 antenna patterns 31, 32, 33 is formed in a substantially rectangular plate shape which extends in the longitudinal direction of the insulating substrate 1, bent in an L-shape at the tip by a second lambda _1/4 antenna patterns 32 Thus, a projecting portion 321 extending is formed. lambda _2/4 antenna patterns 41, 42, 43 and 44, insulating the longitudinal direction of the substrate 1 is formed in a plate shape that extends, widening region 411 to gradually widen toward the insulating gap 2 at its base end side, 421, 431, and 441 are formed, respectively.

A first lambda _1/4 antenna pattern 31 first lambda _2/4 antenna pattern 41, the above the insulating gap 2 in the insulating substrate 1 on one surface 11, horizontal side of the base end side 51 and connected. First lambda _1/4 antenna pattern 31, the disposed near one end of the in the width direction on one surface 11, the first lambda _2/4 antenna pattern 41, the one surface 11 The antenna patterns 31, 41 are arranged in parallel with each other in a region other than the lateral side portion 51, and a through hole 71 is provided in the longitudinal direction at the separation portion of the insulating substrate 1. It is formed to extend to. The through hole 71, between the first lambda _1/4 antenna pattern 31 and the first lambda _2/4 antenna pattern 41, a third lambda _1/4 antenna pattern 33 below the third lambda _2/4 Impedance is increased by interposing an air layer (dielectric constant ε = 1.0) having a dielectric constant smaller than that of the insulating substrate 1 between the antenna pattern 43 and the antenna patterns 31 and 33 that resonate with the wavelength λ ₁ and the wavelength λ _2. Thus, the isolation characteristics of the antenna patterns 41 and 43 that resonate can be improved.

A second lambda _1/4 antenna pattern 32 and the second lambda _2/4 antenna pattern 42, the under side of the in insulating gap 2 on one surface 11, connecting the base end side in horizontal side 52 Is formed. Second lambda _1/4 antenna pattern 32, the near one end of the in the width direction on one surface 11, substantially the same straight line with the first lambda _1/4 antenna patterns 31 spaced apart by an insulating gap 2 is arranged so as to Jo, the second lambda _2/4 antenna pattern 42 near the other end in the width direction of the one surface 11, the first lambda _2/4 spaced apart by an insulating gap 2 The antenna patterns 41 are arranged so as to be substantially in the same straight line, and both the antenna patterns 32 and 42 are arranged apart from each other in a region other than the lateral side portion 52, and a through hole 72 is formed at the separated portion of the insulating substrate 1. It is formed to extend in the longitudinal direction. The through-hole 72, as in the case of the through hole 71, an air layer is interposed between the second lambda _1/4 antenna pattern 32 and the second lambda _2/4 antenna pattern 42, the isolation characteristic Can be increased.

Third lambda _1/4 antenna pattern 33 and the third lambda _2/4 antenna pattern 43 on the upper side of at insulating gap 2 to the other surface 12, connecting the base end side in horizontal side 53 Is formed. Third lambda _1/4 antenna pattern 33, the disposed near one end of the other side 12 in the width direction, a third lambda _2/4 antenna pattern 43, the other surface 12 The antenna patterns 33, 43 are arranged in parallel with each other in a region other than the lateral side portion 53, and the through hole 71 is arranged at the separation portion of the insulating substrate 1. ing. The third antenna patterns 33 and 43 connected by the lateral side portion 53 of the other surface 12 are substantially the same shape as the first antenna patterns 31 and 41 connected by the lateral side portion 51 of the one surface 11, the same size, are oppositely arranged such shape corresponding across the insulating substrate 1, a third lambda _1/4 antenna pattern 33 on the back side of the first lambda _1/4 antenna pattern 31, a first lambda _2/4 antenna pattern 41, a third lambda _2/4 antenna pattern 43 on the back side of the widening region 411, widening region 431, horizontal side 53 is disposed on the rear side of the horizontal side 51.

Fourth lambda _2/4 antenna pattern 44 on the lower side of in the insulating gap 2 to the other surface 12 is formed so as to extend along the horizontal side 54 in the insulating gap 2. Fourth lambda _2/4 antenna pattern 44 is disposed near the other end in the width direction of the other surface 12, through holes 72 are disposed near the substantially tip. The other in the plane 12 of the fourth lambda _2/4 antenna pattern 44 and the horizontal side 54, in the surface 11 of the one second lambda _2/4 antenna pattern 42 and the horizontal side 52 and substantially isomorphic, the same size, are oppositely arranged such shape corresponding across the insulating substrate 1, the second lambda _2/4 antenna pattern 42, the widening region 421, a fourth lambda ₂ on the rear side of the horizontal side 52 / 4 antenna pattern 44, widened region 441, and lateral side portion 54 are arranged. Note that the lower side of in the insulating gap 2 to the other surface 12, lambda _1/4 antenna pattern is not disposed.

A plurality of through holes 6 penetrating in the thickness direction are formed at predetermined positions corresponding to the antenna patterns 31, 33, 41 to 44 and the insulating substrate 1, and the antenna patterns 31, 33 are formed on the peripheral walls of the through holes 6. The conductors conducting to 41 to 44 are plated. Insulating substrate 1 interposed therebetween opposing lambda _1/4 antenna pattern 31 and 33, and the lambda _2/4 antenna pattern 41 43, and lambda _2/4 antenna pattern 42 44, the conductors plating of the through-holes 6, respectively Thus, the current distributions of the antenna patterns on the one surface 11 and the other surface 12 become equal.

  The insulating substrate 1 on which the antenna patterns 31 to 33 and 41 to 44 are formed is fitted to the base end portion 13 where the antenna pattern is not formed in the fitting recess 81 of the holder 8 installed in the electronic device. Attached to electronic equipment.

On the other surface 12 side of the insulating substrate 1, a coaxial line 9 is disposed along the longitudinal direction substantially below the insulating gap 2. At the front end side of the coaxial line 9, the inner conductor 91 is connected to the lateral side portion 53 conducting to the upper antenna patterns 31, 33, 41, 43 by soldering or the like, and the antenna patterns 31, 33 in the first frequency band and the first The antenna patterns 41 and 43 in the two frequency bands are connected in a direct current manner. Further, the outer conductor 92 is connected to the lateral side portion 54 that is electrically connected to the lower antenna patterns 32, 42, 44 by soldering or the like, and the antenna pattern 32 in the first frequency band and the antenna patterns 42, 44 in the second frequency band. Is connected in a direct current manner. The proximal end side of the coaxial line 9 is inserted into the insertion hole 82 of the holder 8 and connected to a high frequency circuit in the electronic device. The coaxial line 9 is disposed at a predetermined position so that the air layer 21 is provided away from the other surface 12 by the thickness of the spacer portion 83 between the fitting recess 81 and the insertion hole 82 of the holder 8. The portion near the tip is supported by the solder portion so as to maintain a separated state. The coaxial line 9, across the air layer 21 and the insulating substrate 1 of the separation portion is arranged to overlap the projected portion 321 of the second lambda _1/4 antenna pattern 32 is wider than the coaxial line 9 . The separation distance between the coaxial line 9 and the other surface 12 may be appropriately set so as to prevent leakage current to the holder 8 side in consideration of the impedance between the lateral side portion 53 and the inner conductor 91 and the like. Is possible. Further, the projecting portion 321, near point distance of the outer conductor 92 and the antenna pattern 32 or the like to conduct a horizontal side 54 holder side to lambda _1/4 from the connection point between, i.e. in the vicinity of the portion where the voltage is maximum providing the well, preferably it is preferable that provided λ _1/4 ± 10% about the area around the location of the λ _1/4.

In the dual-frequency antenna of the above embodiment, the antenna patterns 31 to 33 and 41 to 44 are integrally formed on the insulating substrate 1, so that the influence due to the variation in the manufacturing work is eliminated as much as possible to stabilize the quality. It is possible to mass-produce dual-frequency antennas with stable electrical characteristics. Also, a like lambda _1/4 antenna pattern 31 of the first frequency band which is provided in parallel, by providing the through hole 71 or the like between lambda _2/4 antenna pattern 41 and the like of the second frequency band, the through holes It is possible to improve the isolation characteristics of the antenna patterns 31 and 41 etc. in different frequency bands in the air layer interposed in 71 etc. Further, the antenna patterns 31, 41, 32, and 42 are formed on one surface 11 of the insulating substrate 1, and the antenna patterns 33, 43, and 44 are formed on the other surface 12, and conductor plating for providing these in the through holes 6 is performed. Therefore, it is possible to provide an antenna pattern having the same current distribution on one surface 11 and the other surface 12, and the antenna gain can be made uniform in almost all directions. Further, by providing the widened region 411 to 441 in lambda _2/4 antenna patterns 41 to 44, lowering the inductance L of the resonance wavelength lambda _2, further, a widening region 411 that face each other across the insulating substrate 1 431,421 441, the capacity C can be increased and the quality factor Q can be reduced, and the frequency characteristics can be widened.

  In addition, the coaxial line 9 is disposed on the other surface 12 side of the insulating substrate 1 so as to be separated from the end of the antenna pattern 31, 41 on the one surface 11 on the holder 8 side and the outer conductor 92 of the coaxial line 9. Further, the protruding portion 321 and the coaxial line 9 formed on the antenna pattern 32 on the one surface 11 are connected to the insulating substrate 1 and the insulating substrate 1 held by the spacer 83 and the coaxial line. 9 are arranged so as to sandwich the air layer 21 in the separated portion, and the dielectric constant between the antenna pattern 32 and the projecting portion 321 and the coaxial line 9 is a composite dielectric constant of the dielectric constant of the insulating substrate and the dielectric constant of air. Thus, the impedance can be further increased, and the effect of preventing leakage current to the holder 8 side, that is, the electronic device side on which the holder 8 is installed can be enhanced.

The non-grounded dual-frequency antenna of the above embodiment can be installed in various electronic devices with the holder 8 attached to the housing. For example, personal computers such as mobile phones, personal digital assistants, notebook computers, etc. It can be installed in electronic devices such as computers, electronic books, and in-vehicle terminals.
[Example]
The dual frequency antenna of the non-grounded in the above embodiment, lambda _1/4 antenna patterns 31 to 33 of the target frequency band of the first frequency band 2.4 GHz to 2.5 GHz, the lambda _2/4 antenna pattern 41-42 The target frequency band is configured as the second frequency band 4.9 GHz to 5.9 GHz, and the results of measuring the radiation directivity characteristics in the horizontal plane with respect to the vertical polarization are shown in FIGS. 4 and 5. FIG. 4 shows horizontal radiation directivity characteristics for vertical polarization in the first frequency band 2.4 to 2.5 GHz, and FIG. 5 shows horizontal radiation directivity characteristics for vertical polarization in the second frequency band 4.9 to 5.9 GHz. is there. A substantially uniform radiation directivity characteristic was obtained in all directions for the first frequency band and the second frequency band, and the antenna gain was about 2.14 dBi in any direction. Further, as shown in FIG. 6, VSWR was smaller than 2.0 over the entire first frequency band and the entire second frequency band, and good VSWR characteristics were exhibited. Furthermore, the ratio band (%) of VSWR 2.0 with respect to the center frequency of 5.36 GHz in the second frequency band is ((0.47 GHz * 4 scale) /5.36 GHz) × 100 is about 35%. In the frequency band, it showed very wide band characteristics.

  The dual-frequency shared antenna of the present invention can be used as an antenna of an electronic device used for a wireless LAN, for example.

The top view of the dual frequency antenna of an embodiment. The side view of the dual frequency shared antenna of the embodiment. The back view of the dual-frequency common antenna of an embodiment. The figure which shows the radiation directivity characteristic in a horizontal surface with respect to the 2.4-GHz-band vertical polarized wave in the dual frequency antenna of embodiment. The figure which shows the radiation directivity characteristic in a horizontal surface with respect to the vertical polarized wave of 5 GHz band in the dual frequency antenna of embodiment. The figure which shows the VSWR characteristic in the dual frequency shared antenna of embodiment.

Explanation of symbols

1 insulating substrate 11 on one surface 12 second surface 13 proximal end 2 insulating gap 21 air layer 31, 32, 33 lambda _1/4 antenna pattern 321 protruding portions 41, 42, 43, 44 lambda _2/4 antenna pattern 411, 421, 431, 441 Widened regions 51, 52, 53, 54 Horizontal side 6 Through hole 71, 72 Through hole 8 Holder 81 Fitting recess 82 Insertion hole 83 Spacer 9 Coaxial line 91 Internal conductor 92 External conductor

Claims (6)

An antenna pattern which resonates the insulating elongate substrates at the wavelength lambda _1, is provided integrally with an antenna pattern which resonates at the wavelength lambda ₁ and wavelength different lambda _2, a non-ground type dual frequency antenna, the insulating substrate on one surface of the first, second lambda _1/4 antenna pattern, and the first, the second lambda _2/4 antenna pattern, extending spaced apart in each insulating gap in the longitudinal direction substantially the same straight line was set, the first lambda _1/4 antenna pattern and the first lambda _2/4 antenna patterns, and a second lambda _1/4 antenna pattern and the second lambda _2/4 antenna pattern, at least the insulating gap respectively A dual-frequency antenna that is separated in a region other than the vicinity. Spacing of the first lambda _1/4 antenna pattern and the first lambda _2/4 wherein the spaced portions of the antenna pattern the second lambda _1/4 antenna pattern and the second lambda _2/4 antenna pattern of said insulating substrate The dual-frequency antenna according to claim 1, wherein a through hole is provided at each location. Wherein the other surface of the insulating substrate, via a third lambda _1/4 conductor antenna pattern disposed on the first lambda _1/4 antenna pattern and a position substantially corresponding to provided in the through hole of the insulating substrate connect, third, through the fourth lambda _2/4 first respective antenna pattern, the second lambda _2/4 conductor antenna pattern and be disposed in a position substantially corresponding to provided in the through hole of the insulating substrate The dual-frequency antenna according to claim 1, wherein the dual-frequency antenna is connected. First, towards the insulation gap to the second lambda _2/4 antenna patterns provided an area for widening, so as to face the widening region, the insulating third and fourth lambda _2/4 antenna pattern 4. The dual frequency antenna according to claim 3, wherein a region that widens toward the gap is provided. First, second lambda _1/4 antenna pattern, and the first, the along the coaxial line connected by the insulating gap near the second lambda _2/4 antenna pattern substantially in longitudinal direction of the insulating substrate other characterized in that the disposed spaced on the side, providing the first or protrusion disposed the overlap with coaxial line the coaxial line from a wide to at least the tip of the second lambda _1/4 antenna pattern The dual-frequency antenna according to any one of claims 1 to 4. An electronic apparatus comprising the dual-frequency antenna according to claim 1.

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