JP5785007B2 - ANTENNA DEVICE AND COMMUNICATION DEVICE - Google Patents

Description

  The present invention relates to an antenna device that performs information communication by electromagnetic field coupling between a pair of electrodes facing each other at a predetermined communication wavelength, and a communication device in which the antenna device is incorporated.

  In recent years, a system has been developed in which data such as music and images is transmitted wirelessly between electronic devices such as computers and small portable terminals without using cables or media. Some of such wireless transmission systems are capable of high-speed transfer of up to about 560 Mbps at a short distance of several centimeters. Among such transmission systems capable of high-speed transfer, TransferJet (registered trademark) is advantageous in that the communication distance is short but the possibility of eavesdropping is low and the transmission speed is high.

  TransferJet (registered trademark) can be achieved by electromagnetic field coupling of corresponding high frequency couplers at very short distances, and the signal quality depends on the performance of the high frequency coupler. For example, as shown in FIG. 16, a high-frequency coupler described in Patent Document 1 has a printed circuit board 201 in which a ground 202 is formed on one surface and a microstrip structure formed on the other surface of the printed circuit board 201. The stub 203 includes a coupling electrode 208 and a metal wire 207 that connects the coupling electrode 208 and the stub 203. In the high frequency coupler described in Patent Document 1, a transmission / reception circuit 205 is also formed on the printed circuit board 201. Further, in Patent Document 1, as a modified example in which the transmission / reception circuit 205 is not formed on the printed circuit board 201, a printed circuit board 201 in which a ground 202 is formed on one surface as shown in FIG. A configuration including a microstrip structure stub 203 formed on the other surface, a coupling electrode 208, and a metal wire 207 connecting the coupling electrode 208 and the stub 203 is described.

  However, as shown in FIG. 16, the high-frequency coupler described in Patent Document 1 needs to increase the area of the plate-like coupling electrode 208 in order to perform good communication. This is because a certain length depending on the communication wavelength is necessary, and in order to increase the coupling strength, the coupling electrode 208 must be enlarged. In addition, since the metal wire 207 needs to connect the coupling electrode 208 and the stub 203 at a predetermined position, there is a problem in process such that alignment accuracy is required at the time of manufacture.

  In order to solve these problems, Non-Patent Document 1 discloses an antenna device having a structure in which electromagnetic coupling is performed in a direction perpendicular to the end face of the antenna device (hereinafter referred to as an end radiation type). . Here, as shown in FIG. 18A, the three-dimensional orthogonal coordinate system is XYZ, and the end face of the antenna device 300 published from Non-Patent Document 1 is the XY plane. In FIG. 18A, the outer dimensions defined by the XYZ axes are 25 [mm], 0.1 to 0.3 [mm], and 10 [mm], respectively. In this case, as shown in FIG. 18B, the antenna device 300 includes a ground 313 formed on the surface XZ of the dielectric substrate 311, a line 312 formed at a certain distance from the ground 313, A power supply unit 314 is provided in the approximate center of the line 312 and supplies power to the ground 313. If the line 312 is designed to be about half the wavelength of the communication wavelength, both ends of the line 312 become open stubs having a length of ¼ wavelength from the power feeding unit 314, and strong electric field radiation is centered around both ends of the line 312. Occur. As a result, the antenna device 300 can obtain strong electromagnetic coupling between the line 312 and the electrode disposed in a plane-symmetric position with respect to the plane XY of the dielectric substrate 311.

JP 2008-31816 A

Hitachi Cable News Release 2011.9.17, Hitachi Cable, Ltd., 2010.10.5, CEATEC exhibition, http://www.hitachi-cable.co.jp/products/news/20100917.html

  However, in the antenna device 300 described in Non-Patent Document 1 described above, the length of the line 312 needs to be designed to be approximately half the communication wavelength as shown in FIG. In the example shown in FIG. 18A, a length of 12.5 [mm] from the center position defined in the X-axis direction, and a total length of 25 [mm] are required. Although it is possible to reduce the thickness, it is difficult to reduce the size of the surface XZ, particularly in the direction in which the line 312 is routed.

  The present invention has been proposed in view of such circumstances, and has a structure that is advantageous for both miniaturization and low profile while realizing both good communication characteristics and mechanical strength. An object is to provide an antenna device. Another object of the present invention is to provide a communication device in which this antenna device is incorporated.

As a means for solving the above-described problems, an antenna device according to the present invention is an antenna device that performs information communication by electromagnetic coupling between a pair of electrodes facing each other at a predetermined communication wavelength. A coupling electrode that is formed and electromagnetically coupled to electrodes of other antenna devices to enable communication, and the coupling electrode is formed on one surface of the dielectric substrate and has a length that is ½ of the communication wavelength. A first wiring, a conductor facing the first wiring in the surface direction of the dielectric substrate and electrically connected to the first wiring, and a central portion of the first wiring and a conductor; Are coupled to the electrodes of other antenna devices arranged on the extension line connecting the conductors, the conductor is a ground formed on the same surface of the first wiring and the dielectric substrate, and the first wiring is a ground A substantially loop formed at a predetermined distance outside Consists Jo, with its one end is ground and electrically connected, powered as an input terminal of the supply voltage the other end relative to the ground, characterized in Rukoto.
The antenna device according to the present invention is an antenna device that performs information communication by electromagnetic field coupling between a pair of electrodes facing each other at a predetermined communication wavelength. The antenna device is formed on a dielectric substrate and is an electrode of another antenna device. And a coupling electrode that can communicate with each other by electromagnetic field coupling, and the coupling electrode has a length of ½ of a communication wavelength and a first wiring formed on one surface of the dielectric substrate; 1 and a conductor that is opposed to the surface of the dielectric substrate and electrically connected to the first wiring, and is disposed on an extension line that connects the central portion of the first wiring and the conductor. The antenna is electromagnetically coupled to the electrode of the antenna device, and the conductor is a second wiring having a length of ½ of the communication wavelength, and one end of the second wiring is electrically connected to one end of the first wiring. connected, the coupling electrode, the central portion of the first wiring and the central portion of the second wiring Characterized by coupling electrode and the electromagnetic field of another antenna device which is disposed on an extended line connecting.

The communication device according to the present invention is a communication device that performs information communication by electromagnetic coupling between a pair of electrodes facing each other at a predetermined communication wavelength. And a coupling electrode that is electromagnetically coupled to enable communication, and a transmission / reception processing unit that is electrically connected to the coupling electrode and performs signal transmission / reception processing. A first wiring having a length and formed on one surface of the dielectric substrate, and a conductor that is opposed to the first wiring in the surface direction of the dielectric substrate and is electrically connected to the first wiring. It has an electromagnetic field coupling with an electrode of another antenna device arranged on an extension line connecting the central portion of the first wiring and the conductor, and the conductor is formed on the same surface of the first wiring and the dielectric substrate. The first wiring has a predetermined distance outside the ground. It consists substantially loop-shape formed at a, with its one end connected to ground and electrically, characterized in that it is powered as an input terminal of the supply voltage the other end relative to the ground.
The communication device according to the present invention is a communication device that performs information communication by electromagnetic coupling between a pair of electrodes facing each other at a predetermined communication wavelength. And a coupling electrode that is electromagnetically coupled to enable communication, and a transmission / reception processing unit that is electrically connected to the coupling electrode and performs signal transmission / reception processing. The first wiring formed on one surface of the dielectric substrate having a length, the central portion of the first wiring opposed to the surface direction of the dielectric substrate, and electrically connected to the first wiring And an electromagnetic field coupling with an electrode of another antenna device arranged on an extension line connecting the central portion of the first wiring and the conductor, and the conductor has a length of ½ of the communication wavelength. A second wiring, wherein one end of the second wiring is electrically connected to one end of the first wiring. Is connected, the coupling electrode is characterized in that the coupling the first central portion and the electrode and the electromagnetic field of another antenna device which is disposed on an extended line connecting the center portion of the second wiring lines .

  In the present invention, since the first wiring and the conductor are formed on one surface of the dielectric substrate, the mechanical strength can be realized.

  Further, the present invention provides an extension line connecting the central portion of the first wiring having a length of ½ of the communication wavelength and the central portion of the first wiring and the conductor facing the surface direction of the dielectric substrate. By electromagnetically coupling with the electrodes of other antenna devices placed, the degree of freedom in adjusting the aspect ratio defined by the surface direction of the dielectric substrate is high, and both miniaturization and low profile of the antenna device are achieved. However, good communication characteristics can be realized.

  Therefore, according to the present invention, it is possible to achieve both a reduction in the size and a reduction in the height of the antenna device while making it possible to achieve both good communication characteristics and mechanical strength.

It is a figure which shows the structure of the communication system with which the antenna device to which this invention was applied is integrated. It is a figure which shows the structure of the high frequency coupler which concerns on 1st Embodiment which is an antenna device to which this invention was applied. It is a perspective view which shows the communication state between high frequency couplers in the high frequency coupler which concerns on 1st Embodiment. It is an electric field distribution map which shows the electric field analysis result in the central section in the high frequency coupler concerning a 1st embodiment. It is a frequency characteristic figure which shows the analysis result of the coupling strength between the high frequency coupler concerning a 1st embodiment, and a standard coupler. It is a figure which shows the structure of the high frequency coupler which concerns on 2nd Embodiment which is an antenna apparatus with which this invention was applied. It is a perspective view which shows the communication state between high frequency couplers in the high frequency coupler which concerns on 2nd Embodiment. It is an electric field distribution map which shows the electric field analysis result in the central section in the high frequency coupler concerning a 2nd embodiment. It is a frequency characteristic figure which shows the analysis result of the coupling strength between the high frequency coupler concerning a 2nd embodiment, and a standard coupler. It is a figure which shows the structure of the high frequency coupler which concerns on the modification of 2nd Embodiment which is an antenna device to which this invention was applied. It is a perspective view which shows the communication state between high frequency couplers in the high frequency coupler which concerns on the modification of 2nd Embodiment. It is a frequency characteristic figure which shows the analysis result of the coupling strength between the high frequency coupler concerning the modification of a 2nd embodiment, and a standard coupler. It is an electric field distribution diagram which shows the electric field analysis result in the central section in the high frequency coupler concerning the modification of a 2nd embodiment. It is a figure which shows the analysis result of the magnetic field vector distribution of the high frequency coupler which concerns on the modification of 2nd Embodiment. It is a figure for demonstrating the specific example of the electronic device with which the antenna device to which this invention was applied was integrated. It is a figure which shows the structure of the high frequency coupler which concerns on a prior art example. It is a figure which shows the structure of the high frequency coupler which concerns on a prior art example. It is a figure which shows the structure of the high frequency coupler which concerns on a prior art example.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. It should be noted that the present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the present invention.

<Communication system>
An antenna device to which the present invention is applied is a device that performs information communication by electromagnetic coupling between a pair of opposed electrodes, and is a communication system that enables high-speed transfer of about 560 Mbps, for example, as shown in FIG. 100 is used by being incorporated.

  The communication system 100 includes communication devices 101 and 105 that perform two data communications. Here, the communication apparatus 101 includes a high-frequency coupler 102 having a coupling electrode 103 and a transmission / reception circuit unit 104. In addition, the communication device 105 includes a high-frequency coupler 106 having a coupling electrode 107 and a transmission / reception circuit unit 108.

  As shown in FIG. 1, when the high-frequency couplers 102 and 106 provided in each of the communication devices 101 and 105 are arranged to face each other, the two coupling electrodes 103 and 107 operate as one capacitor, and the band-pass filter as a whole. By operating in this way, a high-frequency signal in the 4 to 5 GHz band for realizing high-speed transfer of, for example, about 560 Mbps can be efficiently transmitted between the two high-frequency couplers 102 and 106.

  Here, the transmitting and receiving coupling electrodes 103 and 107 included in the high-frequency couplers 102 and 106 are arranged to face each other with a distance of, for example, about 3 cm, and can be coupled to each other.

  In the communication system 100, for example, the transmission / reception circuit unit 104 connected to the high-frequency coupler 102 generates a high-frequency transmission signal based on the transmission data when a transmission request is generated from a higher-level application, and the coupling electrode 103 generates a coupling electrode. The signal is propagated to 107. Then, the transmission / reception circuit unit 108 connected to the reception-side high-frequency coupler 106 demodulates and decodes the received high-frequency signal, and passes the reproduced data to the higher-level application.

  The antenna device to which the present invention is applied is not limited to the above-described one that transmits a high frequency signal in the 4 to 5 GHz band, and can be applied to signal transmission in other frequency bands. A high frequency signal in the 4 to 5 GHz band will be described as a transmission target.

<First Embodiment>
As an antenna device incorporated in such a communication system 100, a high-frequency coupler 10 according to the first embodiment as shown in FIG. 2 will be described.

  In FIG. 2, a protective film 15 is shown in a transparent manner for easy understanding of a connection state of a line 12 and a ground 13 described later.

  As shown in FIG. 2, the high-frequency coupler 10 has a structure in which a ground 13 is formed on one surface of a dielectric substrate 11 and a loop-shaped line 12 is formed on the outer periphery of the ground 13 at a predetermined distance.

  The line 12 functions as a coupling electrode 17, and one end of the line 12 is opposed to the ground 13 to serve as a power feeding unit 14 that is a connection unit with the transmission / reception circuit unit 104 described above, and the other end of the line 12 is electrically connected to the ground 13. Connected. Further, the line 12 functioning as the coupling electrode 17 has its wiring length adjusted to be approximately half the communication wavelength.

  As is apparent from the following evaluation, the high-frequency coupler 10 having such a configuration has a line 12 functioning as the coupling electrode 17 at a position away from the power feeding unit ¼ of the communication wavelength, that is, the line The signal level is high at the line center portion 12a, which is the center portion of the twelve. Thereby, in the line center part 12a, it becomes a substantially symmetrical electric field distribution with respect to the formation surface of the ground 13. As a result, the coupling electrode 17 efficiently emits a longitudinal wave of the electric field in the surface direction E of the dielectric substrate 11 shown in FIG. 2, specifically, in the direction of the extension line connecting the line center portion 12 a and the ground 13. can do. As a result, the high-frequency coupler 10 has a strong coupling strength between the other coupling electrodes arranged so as to be plane-symmetric with the end face 11a of the dielectric substrate 11, and realizes good communication characteristics. Can do.

  The high frequency coupler 10 having such a configuration is manufactured by the following manufacturing process. First, of a single-sided copper foil substrate in which, for example, a copper foil is attached to one side of the dielectric substrate 11 as a conductive member, a part of the copper foil surface is removed by etching, and a ground 13 as shown in FIG. A line 12 is formed on the outside of the substrate at a predetermined interval. In the present embodiment, in the dielectric substrate 11, the line 12 is routed so as to surround the outer periphery of the ground 13 from the viewpoint of reducing the area in the surface direction. At the time of this formation, one end 12 b of the line 12 is kept connected to the ground 13. Then, the high frequency coupler 10 is completed by sticking the protective film 15 on the copper foil surface from which the power feeding unit 14 is omitted. In addition, the protective film 15 is for protecting a copper foil surface, and a resist etc. can be substituted and should just be installed as needed.

  In the high-frequency coupler 10 manufactured as described above, a portion between the other end portion 12c of the line 12 functioning as the coupling electrode 17 and the ground 13 functions as a power feeding portion 14, and the power feeding portion 14 is a transmission / reception circuit. It becomes a connection part with the part 104.

  The shape of the power supply unit 14 is changed to a connection method with the transmission / reception circuit unit 104, such as a coaxial cable, an ACF (anisotropic conductive film) with a flexible printed circuit board FPC, or an ACP (anisotropic conductive paste). It is preferable to adjust according to the use of the connection used.

  By the manufacturing process described above, the high-frequency coupler 10 can be manufactured by processing a single-sided copper foil substrate, and does not require processing such as alignment of complex patterns or inter-surface connection by through-holes. Can be manufactured by a simple process.

  Thus, since the high frequency coupler 10 can be completed by etching the copper foil on one side of the single dielectric substrate 11, it is excellent in mechanical strength. In addition, since the high frequency coupler 10 radiates such that the electric field is distributed in the plane direction of the dielectric substrate 11, for example, the high frequency coupler 10 is radiated so that the electric field is distributed in the thickness direction of the dielectric substrate. In comparison, it is not necessary to increase the thickness of the dielectric substrate in order to improve communication performance, and the overall height can be reduced.

  Further, in the high frequency coupler 10, as a material of the dielectric substrate 11, glass, a paper base material, or a glass fiber woven fabric is hardened with an epoxy resin, a phenol resin, etc. Dielectric constant polyimide, liquid crystal polymer, polytetrafluoroethylene, polystyrene, polyethylene, polypropylene, or the like, or a material obtained by making them porous can be used.

  In the manufacturing process described above, in the high-frequency coupler 10, the line 12 is formed as the coupling electrode 17 by the etching process using the single-sided substrate on which the copper foil is bonded, but the surface of the dielectric substrate 11 is plated and vacuumed. It may be formed directly by a masking state by vapor deposition or the like, or may be formed by a patterning process such as etching after formation, or may be formed by a printing method using a conductive paint.

  In addition to copper, a good conductor such as aluminum, gold, silver, or the like can be used as the material for the line 12 and the ground 13 that function as the coupling electrode 17. Any conductor can be used.

  Further, since the coupling electrode 17 has the line 12 formed in a loop shape, the surface space of the dielectric substrate 11 can be used effectively, and the area of the high-frequency coupler 10 itself can be reduced. .

  The high-frequency coupler 10 including such a coupling electrode 17 has a structure in which an electromagnetic field is radiated from the surface direction E of the dielectric substrate 11 as described above, that is, from the end portion of the substrate. Compared with a structure that radiates an electromagnetic field in the vertical direction, it is not necessary to increase the thickness of the dielectric substrate in order to improve communication performance, and the height can be reduced.

  Next, in order to investigate the performance of the high-frequency coupler 10 according to the first embodiment, the coupling strength was analyzed using a three-dimensional electromagnetic field simulator HFSS manufactured by Ansoft. Here, an analysis model of the high-frequency coupler 10 was used under the following conditions. That is, a glass epoxy substrate having a dielectric constant of 4.3 was set as the material of the dielectric substrate 11, and copper having a thickness of 40 μm was set as the conductor material of the coupling electrode 17. The size of the high-frequency coupler 10 was 15 mm × 10.2 mm, and the thicknesses of the dielectric substrate 11 and the protective film 15 were 0.3 mm and 0.05 mm, respectively.

  The coupling strength is evaluated by the S-parameter transmission characteristic S21 used for evaluating the high-frequency transmission characteristic, and a pair of high-frequency couplers using the power feeding unit 14 serving as a signal input / output terminal of the high-frequency coupler 10 as an input port. The bond strength S21 between the ports was calculated.

  FIG. 3 shows the relative arrangement between the high-frequency couplers used for the analysis of the coupling strength S21. In this evaluation, one high-frequency coupler has a plate-like electrode 150a as shown in FIG. 3, and a reference high-frequency coupler 150 serving as a reference machine for evaluation was used. As shown in FIG. 3, the evaluation of the coupling strength is such that the direction E of the extension line connecting the line center portion 12a and the ground 13 and the surface of the electrode 150a of the reference high frequency coupler 150 are orthogonal to each other. The frequency characteristics of the coupling strength S21 were examined in a state where the coupling electrode 17 and the electrode 150a were opposed to each other with the center axes of the electrodes coincided with each other and 15 mm and 100 mm apart from each other.

  In addition, in order to evaluate the generation state of the electric field in the high frequency coupler 10, the electric field vector distribution in the vicinity of the high frequency coupler 10 at the facing distance of 15 mm was also examined.

  FIG. 4 is an analysis of the electric field distribution at 4 GHz of the high frequency coupler 10, and shows the electric field distribution on the formation surface of the coupling electrode 17 in the dielectric substrate 11 of the high frequency coupler 10. As is apparent from this result, the electric field is distributed on the arc from the center of the coupling electrode 17, that is, the line center 12 a in FIG. 4 to the outside, and is in a good coupling state with the reference high-frequency coupler 150. You can see that

  This is because the length of the line 12 constituting the coupling electrode 17 is substantially half of the communication wavelength, and one end of the line 12 is connected to the ground 13, so-called a short stub. This is because the electric field is maximized at the line center portion 12a corresponding to the / 4 portion. Thus, in the high frequency coupler 10, it was confirmed by analysis that a strong electric field is generated around the central portion of the coupling electrode 17.

  FIG. 5 shows an analysis result of the coupling strength S21 between the high-frequency coupler 10 and the reference high-frequency coupler 150, and −21.6 to −20 in a band of 4 to 6 GHz at a communication distance of 15 mm facing distance. .6 dB, strong coupling strength and flat frequency characteristics. For example, TransferJet (registered trademark) requires a bandwidth of 560 MHz. Generally, the center frequency shifts due to variations in high-frequency couplers and impedance matching with the circuit board. Since it has a sufficiently wide bandwidth, it can be satisfactorily communicated without being affected by these variations. Moreover, the communication interruption | blocking property of 4-5GHz-42dB or less is acquired in the non-communication distance of 100 mm of opposing distances.

  As described above, the high-frequency coupler 10 according to the first embodiment achieves good communication characteristics, as is apparent from the above simulation. Moreover, in the high frequency coupler 10, since the line 12 and the ground 13 are formed in the same planar shape of the dielectric substrate 11, mechanical strength can be realized. Further, in the high frequency coupler 10, the line center portion 12 a of the line 12 having a length of ½ of the communication wavelength and the extension line connecting the line center portion 12 a and the ground 13 facing the surface direction of the dielectric substrate 11. The size adjustment for realizing desired communication characteristics by electromagnetic coupling with electrodes of other antenna devices arranged in the antenna, that is, the adjustment of the aspect ratio defined by the surface direction of the dielectric substrate 11 It is possible to achieve good communication characteristics while achieving both a reduction in size and a reduction in height of the entire apparatus.

<Second Embodiment>
Next, a high-frequency coupler 20 according to the second embodiment as shown in FIG. 6 will be described as an antenna device incorporated in such a communication system 100.

  In FIG. 6, in order to make it easy to understand the winding state of the coil 26 described later, the dielectric substrate 21 is shown through.

  The high frequency coupler 20 includes a dielectric substrate 21 and a coil 26 electrically connected to coils 26a and 26b each having a length approximately equal to a half of the communication wavelength. A connection terminal 28 for connection with the transmission / reception circuit unit 104 is formed. In the coil 26, the signal levels of the coils 26a and 26b are reversed in polarity at the line center portions 26a1 and 26b1 of the coils 26a, that is, at one-fourth and three-fourths of the communication wavelength from one end of the coil 26. By becoming high, it functions as the coupling electrode 27. As a result, the line center portions 26a1 and 26b1 have a substantially symmetrical electric field distribution.

  The coupling electrode 27 having such a configuration efficiently emits a longitudinal wave of an electric field in the surface direction E of the dielectric substrate 21 shown in FIG. 2, specifically, in the direction of the extension line connecting the line center portions 26a1 and 26b1. can do. As a result, the high-frequency coupler 20 has high coupling strength with other coupling electrodes arranged on the extension line connecting the line center portions 26a1 and 26b1, and can realize good communication characteristics.

  Further, the coupling electrode 27 can effectively utilize the space of the dielectric substrate 21 and can reduce the area of the high-frequency coupler 20 itself.

  Further, the high-frequency coupler 20 including such a coupling electrode 27 has a structure in which an electromagnetic field is radiated from the surface direction E of the dielectric substrate 21 as described above, that is, from the end portion of the substrate. As compared with a structure that radiates an electromagnetic field in the vertical direction, it is not necessary to increase the thickness of the dielectric substrate in order to improve communication performance, and the height can be reduced.

  A specific structure of the high-frequency coupler 20 having such a configuration will be described with an example of the following manufacturing process.

  First, a plurality of upper surface lines 23 a and lower surface lines 23 b made of a conductive metal such as copper or aluminum are formed on the upper surface 21 a and the lower surface 21 b of the dielectric substrate 21. At the time of this formation, one end of the upper surface line 23a and one end of the lower surface line 23b and another end of the upper surface line 23a are sequentially overlapped with the lower surface line 23b adjacent to the toroidal direction sandwiching the dielectric substrate 21. At the same time, the arrangement is such that the entire coil 26 has a toroidal shape when completed.

  In addition, about the process which forms the several upper surface line 23a and the lower surface line 23b, you may form by the process of plating, vapor deposition, etc. on the both surfaces of the dielectric substrate 21, or the dielectric substrate 21 by which double-sided copper foil was attached is performed. It may be formed by etching treatment.

  Next, in the dielectric substrate 21 on which the upper surface line 23a and the lower surface line 23b are formed, a plurality of through holes 24 are formed by a drill, a laser, or the like at a position where the upper surface line 23a and the lower surface line 23b overlap each other. By filling these through holes 24 with metal plating or conductive paste, all the upper surface lines 23a and lower surface lines 23b formed on both surfaces of the dielectric substrate 21 are electrically connected through the through holes 24. The toroidal coil 26 is completed.

  Both ends of the coil 26 serve as connection terminals 28 for connection to the transmission / reception circuit unit 104, and are preferably manufactured in a predetermined shape adjusted according to impedance matching.

  As a material of the dielectric substrate 21, glass, paper base material, or glass fiber woven fabric is hardened with epoxy resin, phenol resin, etc., for example, glass epoxy, glass composite substrate, low dielectric constant polyimide, liquid crystal polymer , Teflon, polystyrene, polyethylene, polypropylene and the like can be used. In particular, as the material of the dielectric substrate 21, it is preferable to use a material having a low dielectric constant from the viewpoint of electrical characteristics.

  Next, in order to investigate the performance of the high-frequency coupler 20 according to the second embodiment, the coupling strength was analyzed using a three-dimensional electromagnetic field simulator HFSS manufactured by Ansoft. Here, an analysis model of the high frequency coupler 20 was used under the following conditions. That is, a glass epoxy substrate having a dielectric constant of 4.3 was set as the material of the dielectric substrate 21, and copper having a thickness of 40 μm was set as the material of the coil 26 functioning as the coupling electrode 27. The size of the high frequency coupler 20 was 10 mm × 10 mm and the thickness was 1 mm.

  The coupling strength is evaluated by the transmission characteristic S21 of the S parameter used for evaluating the high frequency transmission characteristic, and the input / output of power is made between both ends of the connection terminals 28 and 28 which are the signal input / output ends of the high frequency coupler 20. Port.

  FIG. 7 shows a relative arrangement between the high-frequency couplers used for the analysis of the coupling strength S21. In this evaluation, one high-frequency coupler has a plate-like electrode 150a as shown in FIG. 7, and a reference high-frequency coupler 150 serving as a reference machine for evaluation was used. As shown in FIG. 7, the evaluation of the coupling strength is performed such that the direction E of the extension line connecting the line center portions 26a1 and 26b1 is orthogonal to the surface of the electrode 150a of the reference high frequency coupler 150 and the center of each electrode. In a state where the axes coincide, the coupling electrode 27 and the electrode 150a are opposed to each other, and the frequency characteristic of the coupling strength S21 is examined in a state where the spacing is 15 mm and 100 mm apart.

  Thus, the central axis of the high-frequency coupler 20 is a position having a length of approximately 1/4 with respect to the connection terminal 28 of the coil 26a, that is, a position having a length corresponding to a quarter wavelength of the communication frequency, A position having a length of approximately 1/4 with respect to the connection terminal 28 of the other coil 26b, that is, a position corresponding to 3/4 wavelength of the communication frequency, is half the thickness of the dielectric substrate 21. This is the direction penetrating in the in-plane direction at the position projected on the surface.

  In addition, in order to see the generation state of the electric field in the high frequency coupler 20, the electric field distribution in the vicinity of the high frequency coupler 20 at the facing distance of 15 mm was also examined.

  FIG. 8 shows the analysis result of the electric field distribution at 4.5 GHz which is the resonance frequency of the high-frequency coupler 20, and there are two places where the electric field is strong in the central axis direction connecting the line center portions 26a1 and 26b1, as if By acting like an electric dipole, it can be seen that the opposing high frequency coupler 150 is electromagnetically coupled.

  FIG. 9 shows an analysis result of the coupling strength S21 between the high-frequency coupler 20 and the reference high-frequency coupler 150, and a favorable coupling strength of −18 dB around 4.5 GHz at a communication distance of 15 mm facing distance. In addition, the non-communication distance with a facing distance of 100 mm has a communication blocking property of −40 dB or less.

  As described above, the high-frequency coupler 20 according to the second embodiment realizes good communication characteristics, as is apparent from the above simulation. Further, in the high frequency coupler 20, since the coil 26 functioning as the coupling electrode 27 is formed in the dielectric substrate 21, mechanical strength such as impact resistance can be realized. Further, in the high-frequency coupler 20, an extension connecting the line center portion 26a1 of the coil 26a having a length of ½ of the communication wavelength and the line center portion 26b1 of the coil 26b having a length of ½ of the communication wavelength. By electromagnetically coupling with electrodes of other antenna devices arranged on the line, for example, a dielectric substrate is used to improve communication performance compared to a structure that radiates an electromagnetic field in a direction perpendicular to the substrate surface. It is not necessary to increase the thickness, and the entire apparatus can be reduced in size and reduced in height.

<Modification of Second Embodiment>
Next, as an antenna device incorporated in such a communication system 100, a high-frequency coupler 30 according to a modification of the second embodiment as illustrated in FIG. 10 will be described.

  In FIG. 10, in order to make it easy to understand the winding state of the coil 36 to be described later, the dielectric substrate 31 is shown through.

  The high frequency coupler 30 includes a dielectric substrate 31 and a coil 36 electrically connected to coils 36a and 36b each having a length approximately half of the communication wavelength. A connection terminal 38 for connection with the transmission / reception circuit unit 104 is formed. Here, the connection terminal 38 includes a terminal 38a that contacts the end of the coil 36a and a terminal 38b that contacts the end of the coil 36b.

  The coil 36 is in a state in which the polarities of the signal levels are reversed from each other at the center of the line 36a1 and 36b1 of each of the coils 36a and 36b, that is, at a position 1/4 or 3/4 of the communication wavelength from one end of the coil 36. By becoming high, it functions as the coupling electrode 37. Thereby, in the line center portions 36a1 and 36b1, a substantially symmetrical electric field distribution is obtained.

  Further, the coil 36 is a winding direction reversal portion where the winding direction is reversed at the line center portions 36a1 and 36b1, respectively. For example, as shown in FIG. 10, in this modification, the coil 36 is wound in the clockwise direction from the terminal 38a to the central part 36a1, and from the central part 36a1 to the central part 36b1 counterclockwise. The structure is such that the portion 36b1 to the terminal 38b are clockwise. In other words, the winding direction of the coil 36 rotates clockwise to a distance corresponding to 0 to 1/4 communication wavelength, and counterclockwise to a distance corresponding to 1/4 to 3/4 communication wavelength. It turns clockwise to a distance corresponding to one communication wavelength.

  The coupling electrode 37 having such a configuration efficiently emits a longitudinal wave of an electric field in the plane direction E of the dielectric substrate 31 shown in FIG. 10, specifically, in the direction of the extension line connecting the line center portions 36a1 and 36b1. can do. As a result, the high-frequency coupler 30 has a strong coupling strength with other coupling electrodes arranged on an extension line connecting the line center portions 36a1 and 36b1, and can realize good communication characteristics.

  In addition, the coupling electrode 37 can effectively use the space of the dielectric substrate 31 and can reduce the area of the high-frequency coupler 30 itself.

  Further, the high-frequency coupler 30 including such a coupling electrode 37 has a structure in which an electromagnetic field is radiated from the surface direction E of the dielectric substrate 31 as described above, that is, from the end portion of the substrate. As compared with a structure that radiates an electromagnetic field in the vertical direction, it is not necessary to increase the thickness of the dielectric substrate in order to improve communication performance, and the height can be reduced.

  A specific structure of the high-frequency coupler 30 having such a configuration will be described with reference to an example of the following manufacturing process.

  First, a plurality of upper surface lines 33a and lower surface lines 33b made of a conductive metal such as copper or aluminum are formed on the upper surface 31a and the lower surface 31b of the dielectric substrate 31. In this formation, one end of the upper surface line 33a and one end of the lower surface line 33b are sequentially overlapped with the other end of the upper surface line 33a sandwiching the dielectric substrate 31 with the lower surface line 33b adjacent in the toroidal direction. At the same time, the coil 36 is arranged in a toroidal shape when completed.

  Specifically, with respect to one end of the connection terminal 38, for example, the end 38a, the winding direction of the coil 36 is determined at the line center portions 36a1 and 36b1 corresponding to the 1/4 communication wavelength and the 3/4 communication wavelength, respectively. An upper surface line 33a and a lower surface line 33b are arranged so as to be reversed.

  Next, in the dielectric substrate 31 on which the upper surface line 33a and the lower surface line 33b are formed, a plurality of through holes 34 are formed by a drill, a laser, or the like at a position where the upper surface line 33a and the lower surface line 33b overlap each other. By filling these through holes 34 with a metal plating process or a conductive paste, all the upper surface lines 33a and lower surface lines 33b formed on both surfaces of the dielectric substrate 31 are electrically connected via the through holes 34. A toroidal coil 36 is completed.

  In the coil 36 thus completed, the winding direction is reversed at the line center portions 36a1 and 36b1, and the coil 36 rotates clockwise to a distance corresponding to 0 to 1/4 communication wavelength, and 1/4 to 3/4 communication. The coil structure rotates counterclockwise to a distance corresponding to the wavelength and clockwise to a distance corresponding to 3/4 to 1 communication wavelength.

  Both ends of the coil 36 serve as connection terminals 38 for connection to the transmission / reception circuit unit 104, and are preferably manufactured in a predetermined shape adjusted according to impedance matching.

  About the process which forms the several upper surface line 33a and the lower surface line 33b, you may form by processes, such as plating and vapor deposition, on the both surfaces of the dielectric substrate 31, or it uses the dielectric substrate 31 by which double-sided copper foil was used. It may be formed by etching.

  As a material of the dielectric substrate 31, for example, a glass epoxy, a glass composite substrate, a low dielectric constant polyimide, a liquid crystal polymer, which is made of glass, paper base material, or glass fiber woven fabric hardened with an epoxy resin, a phenol resin, or the like. , Teflon, polystyrene, polyethylene, polypropylene and the like can be used. In particular, as a material of the dielectric substrate 31, it is preferable to use a material having a low dielectric constant in terms of electrical characteristics.

  In FIG. 10, the coil 36 is formed by the upper surface line 33 a and the lower surface line 33 b of the dielectric substrate 31 and the through hole 34 penetrating the dielectric substrate 31 to complete the high frequency coupler 30. For example, the high frequency coupler 30 may be completed by forming a coil 36 by processing a rigid wire and molding the coil 36 with a resin material.

  Next, in order to investigate the performance of the high-frequency coupler 30 according to the modification of the second embodiment, the coupling strength was analyzed using a three-dimensional electromagnetic field simulator HFSS manufactured by Ansoft. Here, an analysis model of the high frequency coupler 30 was used under the following conditions. That is, the dielectric substrate 31 is a glass epoxy substrate FR4 (Flame Retardant Type 4) frequently used in a printed circuit board, and the material of the coil 36 functioning as the coupling electrode 37 is copper. The size of the high frequency coupler 30 was 10.4 mm × 10.4 mm and the thickness was 1 mm.

  The coupling strength is evaluated by the transmission characteristic S21 of the S parameter used for evaluating the high frequency transmission characteristic, and the power between the two terminals 38a and 38b of the connection terminal 38 serving as the signal input / output terminal of the high frequency coupler 30 is measured. I / O port.

  FIG. 11 shows the relative arrangement between the high-frequency couplers used for the analysis of the coupling strength S21. In this evaluation, one high-frequency coupler has a plate-like electrode 150a as shown in FIG. 11, and a reference high-frequency coupler 150 serving as a reference machine for evaluation was used. As shown in FIG. 11, the evaluation of the coupling strength is performed such that the direction E of the extension line connecting the line center portions 36a1 and 36b1 is orthogonal to the surface of the electrode 150a of the reference high frequency coupler 150, and the center of each electrode. In a state where the axes coincide with each other, the coupling electrode 37 and the electrode 150a are opposed to each other, and the frequency characteristic of the coupling strength S21 is examined in a state where the distance is 15 mm or 100 mm.

  Thus, the center axis of the high-frequency coupler 30 is a position having a length of approximately 1/4 with respect to the terminal 38a of the connection terminal 38, that is, a position having a length corresponding to a quarter wavelength of the communication frequency, At a position where a position having a length of approximately 3/4 with respect to the terminal 38a, that is, a position corresponding to 3/4 wavelength of the communication frequency, is projected onto the half-thickness surface of the dielectric substrate 31. It is a direction that penetrates in the in-plane direction.

  In addition, in order to see the generation state of the electric field in the high frequency coupler 30, the electric field distribution and the magnetic field vector in the vicinity of the high frequency coupler 30 at the facing distance of 15 mm were also examined.

  FIG. 12 shows an analysis result of the coupling strength S21 between the high-frequency coupler 30 and the reference high-frequency coupler 150, and a favorable coupling strength of −18 dB at around 4.5 GHz at a communication distance of 15 mm facing distance. In addition, at a non-communication distance with a facing distance of 100 mm, it has a communication blocking property of −40 dB or less.

  FIG. 13 shows the analysis result of the electric field distribution at 4.48 GHz, which is the resonance frequency of the high frequency coupler 30, and there are two places where the electric field is strong in the central axis direction connecting the line center portions 36a1 and 36b1, as if By acting like an electric dipole, it can be seen that the opposing high frequency coupler 150 is electromagnetically coupled.

  As can be seen from FIG. 13, the position where the electric field becomes stronger is the position of the length of approximately 1/4 of the coil 36 from the terminal 38a of the connection terminal 38, that is, the position corresponding to the 1/4 communication wavelength. Further, strong electromagnetic field coupling can be obtained by penetrating these positions in the in-plane direction from the other terminal 38b to a position that is approximately ¼ of the length of the coil 36.

  As described above, the high-frequency coupler 30 according to the modification realizes good communication characteristics. Further, in the high frequency coupler 30, since the coil 36 functioning as the coupling electrode 37 is formed in the dielectric substrate 31, mechanical strength such as impact resistance can be realized. Further, in the high frequency coupler 30, an extension connecting the line center portion 36a1 of the coil 36a having a length of 1/2 of the communication wavelength and the line center portion 36b1 of the coil 36b having a length of 1/2 of the communication wavelength. By electromagnetically coupling with electrodes of other antenna devices arranged on the line, for example, a dielectric substrate is used to improve communication performance compared to a structure that radiates an electromagnetic field in a direction perpendicular to the substrate surface. It is not necessary to increase the thickness, and the entire apparatus can be reduced in size and reduced in height.

  Furthermore, as is clear from the analysis results shown in FIG. 14, the high frequency coupler 30 can improve the effective inductance of the coil 36, and as a result, the coupling efficiency of the high frequency coupler 30 itself can be improved. it can.

  FIG. 14 shows the analysis result of the magnetic field vector distribution at 4.48 GHz, which is the resonance frequency of the high frequency coupler 30, and is in a plane parallel to the central substrate in the thickness direction of the dielectric substrate 31, that is, the coil 36. The magnetic field vector distribution in a cross section parallel to the substrate is shown on the central axis.

  FIG. 14 shows that the magnetic field penetrating the inside of the coil 36 is in the same direction. The high frequency coupler 30 considers the characteristic that the polarity of the high frequency current changes at half wavelength due to the phase relationship, and the winding direction of the coil 36 whose total length corresponds to one communication wavelength is set to 1/4 communication wavelength, 3 / By reversing at the central portions 36a1 and 36b1 corresponding to the lengths of the four communication wavelengths, the magnetic field penetrating the inside of the coil 36 can be in the same direction.

  In this way, the high frequency coupler 30 can prevent a phenomenon in which magnetic fields generated by currents having locally different polarities cancel each other out inside the coil. Thereby, the high frequency coupler 30 can improve the effective inductance of the coil 36, and as a result, the coupling efficiency of the high frequency coupler 30 itself can be improved.

<Application example>
As described above, the high-frequency couplers 10, 20, and 30 according to the first embodiment and the second embodiment achieve both a reduction in size and a reduction in the height of the entire apparatus. For example, as shown in FIG. It can be incorporated into a memory card 62 or the like for communication by being inserted into a slot 61 or the like provided on an end surface 60a of a portable electronic device 60 such as a cellular phone. Here, when the high frequency coupler 10 is provided in the memory card 62 due to the positional relationship with the high frequency coupler provided in the slot 61, the positional relationship is limited, but the first embodiment and the second embodiment are limited. The high-frequency couplers 10, 20, and 30 according to the embodiment have an advantage that they can be easily incorporated because both the downsizing and the low profile of the entire apparatus are compatible.

  10, 20, 30, 102, 106 High frequency coupler, 11, 21, 31, 311 Dielectric substrate, 11a, 60a End face, 12, 312 line, 12a, 26a1, 26b1, 36a1, 36b1 Line center, 12b, 12c End, 13, 202, 313 Ground, 14, 314 Power supply, 15 Protective film, 17, 27, 37, 103, 107, 208 Coupling electrode, 21a Upper surface, 21b Lower surface, 23a, 33a Upper surface line, 23b, 33b Bottom line, 24, 34 Through hole, 26, 26a, 26b, 36a, 36b Coil, 28, 38 Connection terminal, 38a, 38b terminal, 60 Portable electronic device, 61 slot, 62 Memory card, 100 Communication system, 101, 105 communication device, 104, 108 transmission / reception circuit unit, 1 0 reference EFC, 150a electrode, 201 a printed circuit board, 203 stub 205 transceiver circuit, 207 a metal wire, 300 antenna device

Claims (6)

In an antenna device that performs information communication by electromagnetic field coupling between a pair of opposed electrodes at a predetermined communication wavelength,
A coupling electrode formed on a dielectric substrate and electromagnetically coupled to electrodes of other antenna devices to enable communication,
The coupling electrode is
A first wiring formed on the dielectric substrate having a length of ½ of a communication wavelength, and a central portion of the first wiring is opposed to the surface direction of the dielectric substrate, and is connected to the first wiring. An electrically connected conductor;
Electromagnetically coupled with an electrode of the other antenna device arranged on an extension line connecting the central portion of the first wiring and the conductor ,
The conductor is a ground formed on the same surface of the first wiring and the dielectric substrate,
The first wiring has a substantially loop shape formed at a predetermined distance outside the ground, and one end of the first wiring is electrically connected to the ground, and the other end is fed with reference to the ground. antenna apparatus characterized Rukoto powered as an input terminal of the voltage. In an antenna device that performs information communication by electromagnetic field coupling between a pair of opposed electrodes at a predetermined communication wavelength,
A coupling electrode formed on a dielectric substrate and electromagnetically coupled to electrodes of other antenna devices to enable communication,
The coupling electrode is
A first wiring formed on the dielectric substrate having a length of ½ of a communication wavelength, and a central portion of the first wiring is opposed to the surface direction of the dielectric substrate, and is connected to the first wiring. An electrically connected conductor;
Electromagnetically coupled with an electrode of the other antenna device arranged on an extension line connecting the central portion of the first wiring and the conductor ,
The conductor is a second wiring having a length of ½ of the communication wavelength, and one end of the second wiring is electrically connected to one end of the first wiring;
The antenna is characterized in that the coupling electrode is electromagnetically coupled to an electrode of the other antenna device disposed on an extension line connecting the central portion of the first wiring and the central portion of the second wiring. apparatus. 3. The antenna device according to claim 2 , wherein the first wiring and the second wiring are formed of a coil wound through a through hole over the upper and lower surfaces of the dielectric substrate. 4. The antenna device according to claim 3 , wherein the winding direction is reversed at the center of each of the first wiring and the second wiring. In a communication device that performs information communication by electromagnetic field coupling between a pair of opposed electrodes at a predetermined communication wavelength,
A coupling electrode formed on a dielectric substrate and electromagnetically coupled to an electrode of another antenna device to enable communication;
A transmission / reception processing unit electrically connected to the coupling electrode and performing signal transmission / reception processing;
The coupling electrode is
A first wiring having a length of ½ of the communication wavelength and formed on one surface of the dielectric substrate, a central portion of the first wiring facing the surface direction of the dielectric substrate and the first wiring A conductor electrically connected to one wiring,
Electromagnetically coupled with an electrode of the other antenna device arranged on an extension line connecting the central portion of the first wiring and the conductor ,
The conductor is a ground formed on the same surface of the first wiring and the dielectric substrate,
The first wiring has a substantially loop shape formed at a predetermined distance outside the ground, and one end of the first wiring is electrically connected to the ground, and the other end is fed with reference to the ground. A communication apparatus, wherein power is supplied as a voltage input terminal . In a communication device that performs information communication by electromagnetic field coupling between a pair of opposed electrodes at a predetermined communication wavelength,
A coupling electrode formed on a dielectric substrate and electromagnetically coupled to an electrode of another antenna device to enable communication;
A transmission / reception processing unit electrically connected to the coupling electrode and performing signal transmission / reception processing;
The coupling electrode is
A first wiring having a length of ½ of the communication wavelength and formed on one surface of the dielectric substrate, a central portion of the first wiring facing the surface direction of the dielectric substrate and the first wiring A conductor electrically connected to one wiring,
Electromagnetically coupled with an electrode of the other antenna device arranged on an extension line connecting the central portion of the first wiring and the conductor ,
The conductor is a second wiring having a length of ½ of the communication wavelength, and one end of the second wiring is electrically connected to one end of the first wiring;
The coupling electrode is electromagnetically coupled to an electrode of the other antenna device disposed on an extension line connecting a central portion of the first wiring and a central portion of the second wiring. apparatus.

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