TWI539668B - Antenna device and communication device - Google Patents

Description

Antenna device and communication device

The present invention relates to an antenna device that utilizes a predetermined communication wavelength and performs information communication by electromagnetic field coupling between opposite ones of the electrodes, and a communication device incorporating the antenna device.

Priority is claimed on the basis of Japanese Patent Application No. 2011-023048, filed on Jan. 4, 2011, and Japanese Patent Application No. 2011-148566, filed on Jul. 4, 2011. This application is incorporated by reference to these applications.

In recent years, a system has been developed for wirelessly transmitting music, images, and the like between electronic devices such as computers or small portable terminals without using cables or media. In such a wireless transmission system, there is a high-speed transmission that can perform a maximum of 560 Mbps at a short distance of several cm. In such a high-speed transmission system, TransferJet (registered trademark) has the advantages of a short communication distance but a low probability of being eavesdropped and a high transmission speed.

TransferJet (registered trademark) is a type of electromagnetic field coupled by a high-frequency coupler corresponding to a super close distance, and its signal quality depends on the performance of the high-frequency coupler. For example, as shown in FIG. 16, the high-frequency coupler described in Patent Document 1 includes a printed circuit board 201 having a ground 202 formed on one surface, and a stub of a microstrip structure formed on the other surface of the printed substrate 201 ( The stub 203, the coupling electrode 208, and the metal line 207 connecting the coupling electrode 208 and the stub 203. Further, Patent Document 1 describes In the high frequency coupler, a transceiver circuit 205 is also formed on the printed substrate 201. Further, in Patent Document 1, as a modification in which the transmission/reception circuit 205 is not formed on the printed circuit board 201, a printed circuit board 201 having a ground 202 formed on one surface as shown in FIG. 17 and formed on the printed circuit board is described. A stub 203 of a microstrip structure on the other side of 201, a coupling electrode 208, and a metal line 207 connecting the coupling electrode 208 and a stub 203.

However, as shown in FIG. 16, in the high frequency coupler described in Patent Document 1, in order to perform good communication, it is necessary to enlarge the area of the plate-shaped coupling electrode 208. This is because the coupling electrode 208 must be enlarged for a certain length depending on the communication wavelength and for enhancing the coupling strength. Further, since the metal wire 207 is required to connect the coupling electrode 208 and the wire 203 at a predetermined position, the alignment accuracy and the like are required to be produced, and a problem in the process is caused.

In order to solve such a problem, Non-Patent Document 1 discloses an antenna device having a structure in which an end surface of an antenna device is electromagnetically coupled in a vertical direction (hereinafter referred to as an end portion radiation type). Here, as shown in FIG. 18A, the three-dimensional orthogonal coordinate system is assumed to be XYZ, and the end surface of the antenna device 300 disclosed in Non-Patent Document 1 is an XY plane. In Fig. 18A, the external dimensions specified by the XYZ axis 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 is formed by a ground 313 formed on the surface XZ of the dielectric substrate 311, a line 312 formed at a constant interval from the ground 313, and located substantially at the center of the line 312 and connected to the ground 313. The power supply unit 314 that supplies power between them is configured. If line 312 is designed to be approximately half the wavelength of the communication wavelength, then the line Both ends of 312 are cut lines having a length of 1/4 wavelength from the power supply portion 314, and strong electric field radiation is caused by the both ends of the line 312. Thereby, the antenna device 300 can obtain strong electromagnetic field coupling between the line 312 and the electrode disposed at the XY plane symmetry with the surface of the dielectric substrate 311.

Patent Document 1: Japanese Laid-Open Patent Publication No. 2008-311816

Non-Patent Document 1: Hitachi Cables news release 2010.9.17, Hitachi Cable Co., 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, as shown in Fig. 18B, the length of the line 312 must be designed to be substantially half the wavelength of the communication wavelength, so that the direction of the line 312 requires a certain length, as shown in Fig. 18A. In the meantime, the length of the center position of 12.5 [mm] defined in the X-axis direction and the length of 25 [mm] as a whole are thinner, but the size of the surface XZ is reduced, especially in the direction of the arrangement line 312. It is not easy, so there is a problem that the applicable use is limited.

The present invention has been made in view of the above problems, and an object thereof is to provide an antenna device which can realize both good communication characteristics and mechanical strength and has a structure which is advantageous in both miniaturization and low height. Further, it is an object of the present invention to provide a communication device in which the antenna device is incorporated.

As a means for solving the above problems, the antenna device of the present invention performs electromagnetic communication by electromagnetic field coupling between a pair of opposite electrodes by a predetermined communication wavelength, and is characterized in that it is formed on a dielectric substrate and is provided with another The electrode electromagnetic field of one antenna device is coupled to form a communicable coupling electrode; the coupling electrode has a first wiring formed on one surface of the dielectric substrate and having a length of 1/2 of the communication wavelength, and the first wiring is on the dielectric substrate. The conductor that faces and is electrically connected to the first wiring in the surface direction is coupled to the electrode electromagnetic field of another antenna device that is disposed on the extension line connecting the central portion of the first wiring to the conductor.

Further, the communication device of the present invention is configured to perform information communication by electromagnetic field coupling between a pair of opposite electrodes by a predetermined communication wavelength, and is characterized in that: the coupling electrode is provided on the dielectric substrate and the other antenna device The electrode electromagnetic field is coupled to be communicable; and the transceiver processing unit is electrically connected to the coupling electrode to perform signal transmission and reception processing; the coupling electrode has a length of 1/2 of the communication wavelength and is formed on one side of the dielectric substrate. The first wiring and the conductor that is electrically connected to the first wiring in a direction in which the first wiring faces the dielectric substrate; and the electromagnetic field coupling of the other antenna device disposed on the extension line connecting the central portion of the first wiring and the conductor .

According to the invention, since the first wiring and the conductor are formed on one surface of the dielectric substrate, mechanical strength can be achieved.

Further, according to the present invention, the other antenna device is disposed on an extension line connecting the central portion of the first wiring formed by the length of the communication wavelength of 1/2 and the conductor of the first wiring center portion facing the surface of the dielectric substrate. By coupling the electrode electromagnetic fields, the degree of freedom in adjusting the aspect ratio in the direction of the surface of the dielectric substrate is high, and the antenna device can be reduced in size and height, and good communication characteristics can be realized.

Therefore, the present invention can achieve both good communication characteristics and mechanical strength, and can simultaneously achieve miniaturization and low height of the antenna device itself.

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

<communication system>

An antenna device to which the present invention is applied is a device for performing information communication by electromagnetic field coupling between a pair of opposite electrodes, for example, as shown in FIG. 1, assembled in a communication system 100 capable of high-speed transmission of about 560 Mbps. user.

The communication system 100 is composed of two communication devices 101 and 105 that perform data communication. Here, the communication device 101 includes a high frequency coupler 102 having a coupling electrode 103 and a transmission and reception circuit unit 104. Further, the communication device 105 includes a high frequency coupler 106 having a coupling electrode 107 and a transmission and reception circuit unit 108.

When the high-frequency couplers 102 and 106 included in the communication devices 101 and 105 are arranged to face each other as shown in FIG. 1, the two coupling electrodes 103 and 107 operate as one capacitor, and the whole is grounded as a band-pass filter. Between the two high frequency couplers 102, 106, a high frequency signal for realizing a high frequency transmission of, for example, about 560 Mbps in the 4 to 5 GHz band can be transmitted with high efficiency.

Here, the coupling electrodes 103 and 107 for transmitting and receiving each of the high-frequency couplers 102 and 106 are, for example, separated by about 3 cm and disposed opposite each other to perform electric field coupling.

In the communication system 100, for example, when a transmission request is generated from a high-order application, the transceiver circuit unit 104 connected to the high-frequency coupler 102 generates a high-frequency transmission signal based on the transmission data, and transmits the signal from the coupling electrode 103. It goes to the coupling electrode 107. Then, the transceiver circuit unit 108 connected to the high frequency coupler 106 on the receiving side demodulates and decodes the received high frequency signal, and delivers the reproduced data to the high-end application.

In addition, the antenna device to which the present invention is applied is not limited to the above-mentioned high frequency signals for transmitting the 4 to 5 GHz band, and can also be applied to signal transmission in other frequency bands, but in the following specific examples, the high frequency signals in the 4 to 5 GHz band are used. It is explained as a communication object.

<First embodiment>

As the antenna device incorporated in the communication system 100, the high frequency coupler 10 of the first embodiment shown in Fig. 2 will be described.

In FIG. 2, in order to make it easy to understand the connection state of the wire 12 and the ground 13 mentioned later, it shows through the protective film 15.

As shown in FIG. 2, the high frequency coupler 10 has a structure in which a ground line 13 is formed on one surface of a dielectric substrate and an annular line 12 is spaced apart from the outer circumference thereof.

The wire 12 serves as the coupling electrode 17, and one end thereof faces the ground 13 and serves as a power supply portion 14 to the connection portion of the transmission/reception circuit portion 104. The other end of the wire 12 is electrically connected to the ground 13. Also, used as the coupling electrode 17 Line 12 has a wire length adjusted to approximately half the length of the communication wavelength.

In the high-frequency coupler 10 having the above configuration, it is understood from the next evaluation that the line 12 serving as the coupling electrode 17 is separated from the power supply portion 14 by a quarter of the communication wavelength, that is, the center of the line 12, that is, the center of the line. The portion 12a is in a state in which the signal level is high. Thereby, the formation surface of the line center portion 12a with respect to the ground 13 becomes a substantially symmetrical electric field distribution. Thereby, the longitudinal wave of the electric field is efficiently grounded in the direction E of the dielectric substrate 11 shown in FIG. 2, specifically, in the direction of the extension line of the connection line center portion 12a and the ground 13. As a result, the coupling strength between the high-frequency coupler 10 and the other coupling electrode arranged to be plane-symmetrical with the end surface 11a of the dielectric substrate 11 becomes strong, and good communication characteristics can be realized.

The high frequency coupler 10 having the above configuration is manufactured by the following process. First, a portion of the copper foil surface of the single-sided copper foil substrate to which a single surface of the dielectric substrate 11 is adhered as a conductive member, for example, a copper foil, is removed by an etching process to form the ground 13 and the outer side of the ground 13 as shown in FIG. Line 12 separated by a certain interval. In the present embodiment, the dielectric substrate 11 is wound around the outer circumference of the ground 13 from the viewpoint of reducing the area in the surface direction. At the time of its formation, one end portion 12b of the wire 12 is in a state of being connected to the ground 13 in advance. Next, the high frequency coupler 10 is completed by adhering the protective film 15 to the copper foil surface of the power supply unit 14 omitted. Further, the protective film 15 is for protecting the copper foil surface, and may be replaced by a photoresist or the like, and may be provided as needed.

The high-frequency coupler 10 manufactured as described above functions as a power supply portion 14 between the other end portion 12c of the line 12 functioning as the coupling electrode 17, and the ground portion 13. The power supply portion 14 serves as a connection portion with the transceiver circuit portion 104. .

In addition, the shape of the power supply unit 14 is based on the connection with the transceiver circuit unit 104, for example, a coaxial cable, a flexible printed circuit board FPC, or an ACF (Anisotropic Conductive Film) or ACP (Anisotropic Conductive Paste). The use of the connection is better adjusted.

By the above process, the high-frequency coupler 10 can be fabricated by processing a single-sided copper foil substrate, and does not require complicated pattern alignment or inter-plane connection of through-holes, and can be fabricated by a simple program.

As described above, the high-frequency coupler 10 can be completed by etching a single-sided copper foil of one piece of the dielectric substrate 11, and thus has excellent mechanical strength. Further, since the high-frequency coupler 10 is radiated so as to be distributed in the direction of the surface of the dielectric substrate 11, the high-frequency coupler radiated in the thickness direction of the dielectric substrate, for example, in order to improve communication performance. It is not necessary to make the dielectric substrate thicker, and the overall height can be reduced.

Further, in the high-frequency coupler 10, as the material of the dielectric substrate 11, for example, a glass epoxy such as an epoxy resin, a cured glass such as a phenol resin, a substrate of paper, or a woven fabric of glass fibers can be used. Glass epoxy), glass composite substrate, or low-dielectric polyimide, liquid crystal polymer, polytetrafluoroethylene, polystyrene, polyethylene And polypropylene or the like, or a material which is further porous.

Further, in the above-described process, the high-frequency coupler 10 uses a single-sided substrate to which a copper foil is adhered, and the wire 12 is formed as a coupling electrode 17 by etching, but may be applied to the surface of the dielectric substrate 11. , vacuum evaporation, etc., formed directly in a masking state, or after formation The etching or the like is formed by patterning, and it may be formed by a printing method using a conductive paint.

Further, as the material of the line 12 of the coupling electrode 17 and the ground 13, a good conductor such as aluminum, gold or silver may be used in addition to copper, but it is not particularly limited to these materials, as long as it is a conductive material having high conductivity. Both can be used.

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

The high-frequency coupler 10 including the coupling electrode 17 has a structure in which an electromagnetic field is radiated from the surface direction E of the dielectric substrate 11, that is, from the end portion of the substrate. Therefore, the electromagnetic field is radiated in a direction perpendicular to the substrate surface. In order to improve the communication performance, it is not necessary to make the dielectric substrate thicker, and the height can be reduced.

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

The coupling strength is evaluated by the transmission characteristic S21 of the S parameter (S parameter) used for evaluating the high frequency transmission characteristic to become the high frequency coupler 10 The power supply unit 14 at the signal input/output terminal is an input port, and the coupling strength S21 between the pair of high frequency couplers is calculated.

Fig. 3 shows the relative arrangement between the high frequency couplers used for the analysis of the coupling strength S21. In this example, the high frequency coupler of one of the high frequency couplers of Fig. 3 is a reference high frequency coupler 150 having a plate-like electrode 150a and which is an evaluation reference. As shown in FIG. 3, the evaluation of the coupling strength is a state in which the direction E of the extension line between the central portion 12a of the connection line and the ground 13 is orthogonal to the surface of the electrode 150a of the reference high-frequency coupler 150, and the central axes of the electrodes are aligned. Next, the coupling electrode 17 and the electrode 150a were opposed to each other, and the frequency characteristics of the coupling strength S21 were examined with a gap of 15 mm and 100 mm therebetween.

Further, in order to evaluate the state of generation of the electric field in the high-frequency coupler 10, the electric field vector distribution in the vicinity of the high-frequency coupler 10 having a distance of 15 mm was also investigated.

4 is an analysis of the electric field distribution of the high frequency coupler 10 at 4 GHz, and shows the electric field distribution on the surface on which the coupling electrode 17 of the dielectric substrate 11 of the high frequency coupler 10 is formed. As a result, it is understood that the electric field is distributed in an arc shape from the center portion of the coupling electrode 17 toward the center portion 12a of FIG. 4, and is in a good coupling state with the reference high frequency coupler 150.

This is because the length of the line 12 constituting the coupling electrode 17 is approximately half of the communication wavelength, and one end of the line 12 is connected to the ground 13 to form a so-called short stub. The electric field at the center portion 12a of the portion of the 1/4 of the wavelength is the largest. In this way, in the high-frequency coupler 10, it can be confirmed by analysis that a strong electric field is generated centering on the central portion of the coupling electrode 17.

Fig. 5 is a view showing the analysis result of the coupling strength S21 between the high frequency coupler 10 and the reference high frequency coupler 150. The communication distance of the opposite distance 15 mm is -21.6 to -20.6 dB in the frequency band of 4 to 6 GHz. Strong coupling strength and flat frequency characteristics. For example, in TransferJet (registered trademark), there must be a bandwidth of 560 MHz. Generally, the center frequency is shifted depending on the deviation of the high frequency coupler or the impedance matching with the circuit board, but since the high frequency coupler 10 has A wider bandwidth than the required bandwidth, so that good communication can be performed without being affected by such deviations. Further, in the non-communication distance of the distance of 100 mm, the communication blocking property of 4 to 5 GHz to 42 dB or less can be obtained.

As described above, in the high-frequency coupler 10 of the first embodiment, it is also known from the above simulation that good communication characteristics can be achieved. Further, in the high frequency coupler 10, since the wire 12 and the ground 13 are formed on the same plane of the dielectric substrate 11, mechanical strength can be achieved. Further, in the high-frequency coupler 10, an extension of the ground portion 13a disposed between the line center portion 12a connecting the line 12 composed of the length of the communication wavelength of 1/2 and the line center portion 12a facing the surface of the dielectric substrate 11 is provided. The electrode electromagnetic field of the other antenna device on the line is coupled, thereby achieving a high degree of freedom in the adjustment of the desired communication characteristics, that is, the aspect ratio specified in the direction of the surface of the dielectric substrate 11, and the device as a whole can be realized at the same time. Miniaturization and low height and good communication characteristics.

<Second embodiment>

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

In Fig. 6, in order to facilitate the understanding of the winding state of the coil 26 to be described later, the electric power is made. The dielectric substrate 21 is transmitted and displayed.

The high frequency coupler 20 is composed of a dielectric substrate 21 and coils 26 each having a coil 26a, 26b having a wavelength equal to about 1/2 of the communication wavelength, and is formed at both ends of the coil 26 to be used with the transceiver circuit portion 104. Connect the connection terminal 28. The coil 26 is at a position where the center portions 26a1, 26b1 of the coils 26a, 26b are separated from the ends of the coil 26 by 1/4, 3/4 of the communication wavelength, so that the signal levels are reversed in polarity. The lower portion becomes higher, thereby acting as the coupling electrode 27. Thereby, the line center portions 26a1 and 26b1 have a substantially symmetrical electric field distribution.

In the above-described coupling electrode 27, the longitudinal wave of the electric field can be efficiently grounded in the direction E of the dielectric substrate 21 shown in FIG. 6, specifically, in the direction of the extension line of the connection line center portions 26a1, 26b1. As a result, the coupling strength between the high-frequency coupler 20 and the other coupling electrode disposed on the extension line of the connection line center portions 26a1 and 26b1 is increased, and good communication characteristics can be realized.

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

Further, since the high-frequency coupler 20 including the coupling electrode 27 has a structure in which an electromagnetic field is radiated from the surface direction E of the dielectric substrate 21, that is, from the end portion of the substrate, it is radiated in a direction perpendicular to the substrate surface. In order to improve communication performance, the structure of the electromagnetic field does not require thickening of the dielectric substrate, and the height can be reduced.

The specific structure of the high-frequency coupler 20 having the above configuration will be described by way of an example of the following process.

First, a plurality of upper lines 23a and lower lines 23b made of a conductive metal such as copper or aluminum are formed on the upper surface 21a and the lower surface 21b of the dielectric substrate 21. At the time of completion, one end of the upper line 23a and one end of the lower line 23b, the other end of the upper line 23a and the lower line 23b adjacent to the ring direction are sequentially superposed on each other with the dielectric substrate 21 interposed therebetween, and at the time of completion, at the time of completion The entire coil 26 is arranged in a ring shape.

In addition, the process of forming the plurality of upper lines 23a and the lower lines 23b may be formed on both surfaces of the dielectric substrate 21 by a process such as plating or vapor deposition, and may be formed by adhering the dielectric substrate 21 to the dielectric substrate 21 using a double-sided copper foil.

Next, on the dielectric substrate 21 on which the upper line 23a and the lower 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 line 23a and the lower line 23b overlap each other. By filling the through holes 24 with a metal plating treatment or a conductive paste or the like, all of the upper and lower wires 23a and 23b on both surfaces of the dielectric substrate 21 are electrically connected to each other through the through holes 24, and the ring-shaped coils 26 are completed.

Both ends of the coil 26 are connection terminals 28 for connection to the transceiver circuit portion 104, and are preferably formed in a predetermined shape adjusted in accordance with impedance matching.

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

Next, in order to investigate the performance of the high-frequency coupler 20 of the second embodiment, the three-dimensional electromagnetic field simulator HFSS manufactured by ANSOFT Corporation was used to analyze the coupling strength. Here, as the analysis model of the high-frequency coupler 20, the following conditions are used. In other words, a glass epoxy substrate having a dielectric constant of 4.3 is set to the material of the dielectric substrate 21, and copper having a thickness of 40 μm is set as the material of the coil 26 functioning as the coupling electrode 27. Further, the high frequency coupler 20 has a size of 10 mm × 10 mm and a thickness of 1 mm.

The coupling strength is evaluated by the transmission characteristic S21 of the S parameter (S parameter) used for evaluating the high-frequency transmission characteristic so as to be the output of the power between the terminals 28 and 28 of the signal output terminal of the high-frequency coupler 20 Enter.

Fig. 7 is a view showing the relative arrangement between the high frequency couplers used for the analysis of the coupling strength S21. In this example, a high frequency coupler of one of the high frequency couplers of Fig. 7 is used as the reference high frequency coupler 150 having the plate-like electrode 150a and being evaluated. As shown in FIG. 7, the coupling strength is evaluated in a state where the direction E of the extension line of the connection line center portions 26a1, 26b1 is orthogonal to the surface of the electrode 150a of the reference high frequency coupler 150 and the center axes of the electrodes are respectively aligned. The coupling electrode 27 was opposed to the electrode 150a, and the frequency characteristics of the coupling strength S21 were examined in a state of being spaced apart by 15 mm and 100 mm.

As described above, the central axis of the high-frequency coupler 20 is at a position which is approximately 1/4 of the length of the connection terminal 28 of the coil 26a, that is, a position corresponding to a length of 1/4 wavelength of the communication frequency. Connection of another coil 26b The position at which the terminal 28 is approximately 1/4 of the length of the reference, that is, the position corresponding to the length of the 3/4 wavelength of the communication frequency, is projected in the direction of the in-plane direction at a position on the surface of one half of the thickness of the dielectric substrate 21.

Further, in order to observe the state of generation of the electric field in the high-frequency coupler 20, the electric field distribution in the vicinity of the high-frequency coupler 20 having an opposing distance of 15 mm was also investigated.

8 is a view showing an analysis result of the electric field distribution of the high-frequency coupler 20 at a resonance frequency of 4.5 GHz, and it is understood that two electric field strength portions are generated in the central axis direction of the central portions 26a1 and 26b1 of the connecting line, and operate like an electric dipole, and The opposing high frequency coupler 150 is electromagnetically coupled.

9 is a view showing an analysis result of the coupling strength S21 between the high frequency coupler 20 and the reference high frequency coupler 150. The communication distance of the opposite distance 15 mm has a good coupling strength of -18 dB in the vicinity of 4.5 GHz, and It has a communication blocking degree of -40 dB or less to a non-communication distance of 100 mm.

As described above, in the high-frequency coupler 20 of the second embodiment, it is also known from the above simulation that good communication characteristics can be achieved. 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 achieved. Further, in the high-frequency coupler 20, an extension of the line center portion 26b1 of the coil 26b including the coil 26a having a length of 1/2 of the communication wavelength and the line center portion 26b1 of the coil 26b having a length of 1/2 of the communication wavelength is extended. The electrode electromagnetic field of the other antenna device on the line is coupled, whereby the structure of the electromagnetic field is radiated in a direction perpendicular to the substrate surface, for example, in order to improve the communication performance, the dielectric substrate does not need to be thickened, and the device can be miniaturized and low at the same time. Highly.

<Modification of Second Embodiment>

Next, a high frequency coupler 30 according to a modification of the second embodiment shown in FIG. 10 will be described as an antenna device incorporated in such a communication system 100.

In FIG. 10, in order to make it easy to understand the winding state of the coil 36 mentioned later, the dielectric substrate 31 is transmitted and displayed.

The high frequency coupler 30 is composed of a dielectric substrate 31 and coils 36 electrically connected to coils 36a and 36b each having a length of substantially 1/2 of a communication wavelength, and is formed at both ends of the coil 36 to be connected to the transceiver circuit unit 104. Connect terminal 38. Here, the connection terminal 38 is constituted by a terminal 38a corresponding to the end of the coil 36a and a terminal 38b corresponding to the end of the coil 36b.

The coil 36 is at a position where the center portions 36a1, 36b1 of the coils 36a, 36b are separated from the ends of the coil 36 by 1/4, 3/4 of the communication wavelength, so that the signal levels are reversed in polarity. The lowering becomes higher, thereby acting as the coupling electrode 37. Thereby, the line center portions 36a1 and 36b1 have a substantially symmetrical electric field distribution.

Further, the coil 36 and the line center portions 36a1 and 36b1 are the winding direction reversal portions in which the winding direction is reversed. For example, as shown in Fig. 10, in the present modification, the winding direction of the coil 36 is rotated clockwise from the terminal 38a to the center portion 36a1, the center portion 36a1 is rotated counterclockwise to the center portion 36b1, and the center portion 36b1 is rotated clockwise. To terminal 38b. That is, the winding direction of the coil 36 is rotated clockwise at a distance corresponding to a communication wavelength of 0 to 1/4, and is rotated counterclockwise at a distance corresponding to a communication wavelength of 1/4 to 3/4. It rotates clockwise until it is equivalent to the distance of 3/4~1 communication wavelength.

In the coupling electrode 37 having the above configuration, the longitudinal wave of the electric field can be efficiently grounded in the direction E of the dielectric substrate 31 shown in FIG. 10, specifically, in the direction of the extension line of the connection line center portions 36a1, 36b1. As a result, the coupling strength between the high-frequency coupler 30 and the other coupling electrode disposed on the extension line of the connection line center portions 36a1 and 36b1 is increased, and good communication characteristics can be realized.

Further, the coupling electrode 37 can effectively utilize the space of the dielectric substrate 31, and the area of the high-frequency coupler 30 itself can be reduced.

Further, since the high-frequency coupler 30 including the coupling electrode 37 has a structure in which an electromagnetic field is radiated from the surface direction E of the dielectric substrate 31, that is, from the end portion of the substrate, it is radiated in a direction perpendicular to the substrate surface. In order to improve communication performance, the structure of the electromagnetic field does not require thickening of the dielectric substrate, and the height can be reduced.

The specific structure of the high-frequency coupler 30 having the above configuration will be described by way of an example of the following process.

First, a plurality of upper lines 33a and lower 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. At the time of completion, one end of the upper line 33a and one end of the lower line 33b, the other end of the upper line 33a and the lower line 33b adjacent to the ring direction are sequentially overlapped with each other across the dielectric substrate 31, and are preliminarily completed at the time of completion. The entire coil 36 is arranged in a ring shape.

Specifically, with respect to one end of the connection terminal 38, for example, the end portion 38a, the winding direction of the coil 36 is reversed at the center portions 36a1, 36b1 of the line portions corresponding to the 1/4 communication wavelength and the 3/4 communication wavelength, respectively. Grounding pre-configured separately The upper line 33a and the lower line 33b.

Next, on the dielectric substrate 31 on which the upper line 33a and the lower 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 line 33a and the lower line 33b overlap each other. By filling the through holes 34 with a metal plating treatment or a conductive paste or the like, all of the upper lines 33a and the lower lines 33b formed on both surfaces of the dielectric substrate 31 are electrically connected through the through holes 34, and the loop-shaped coil 36 is completed.

In the coil 36 completed as described above, the winding directions of the in-line center portions 36a1 and 36b1 are reversed, and are rotated clockwise at a distance corresponding to a communication wavelength of 0 to 1/4, which is equivalent to 1/4 to 3/4 communication. The wavelength is rotated counterclockwise until it is a clockwise rotation at a distance corresponding to the communication wavelength of 3/4 to 1.

Both ends of the coil 36 are connection terminals 38 for connection to the transceiver circuit portion 104, and are preferably formed in a predetermined shape adjusted in accordance with impedance matching.

The process of forming the plurality of upper lines 33a and the lower lines 33b may be formed on both surfaces of the dielectric substrate 31 by a process such as plating or vapor deposition, and may be formed by adhering the dielectric substrate 31 to the dielectric substrate 31 using a double-sided copper foil.

As a material of the dielectric substrate 31, for example, a glass epoxy or a glass composite using a cured glass such as an epoxy resin, a phenol resin, a paper substrate, or a glass fiber woven fabric can be used. a substrate, or a low dielectric constant polyimide, liquid crystal polymer, Teflon, polystyrene, polyethylene, and polypropylene. In particular, as the dielectric substrate 31 As the material, from the viewpoint of electrical characteristics, it is preferred to use a material having a low dielectric constant.

Further, in FIG. 10, the high frequency coupler 30 is completed by forming the coil 36 by the upper surface 33a of the dielectric substrate 31 and the lower line 33b and the through hole 34 penetrating the dielectric substrate 31. However, the present invention is not limited to this example, and is processed by, for example, The rigid lead forms the coil 36, and the high frequency coupler 30 can be completed by molding 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 three-dimensional electromagnetic field simulator HFSS manufactured by ANSOFT Corporation was used to analyze the coupling strength. Here, as the analysis model of the high-frequency coupler 30, the following conditions are used. In other words, the dielectric substrate 31 is set to a glass epoxy substrate FR4 (Flame Retardant Type 4) which is often used for a printed circuit board, and copper is set as a material of the coil 36 which functions as the coupling electrode 37. Further, the high frequency coupler 30 has a size of 10.4 mm × 10.4 mm and a thickness of 1 mm.

The coupling strength is evaluated by the transmission characteristic S21 of the S parameter (S parameter) used for evaluating the high-frequency transmission characteristic, so that the two terminals 38a and 38b of the connection terminal 38 of the signal output terminal of the high-frequency coupler 30 are electrically connected. The output is 埠.

Fig. 11 is a view showing the relative arrangement between the high frequency couplers used for the analysis of the coupling strength S21. In this example, a high-frequency coupler of one of the high-frequency couplers of the present invention uses a reference high-frequency coupler 150 having a plate-like electrode 150a and which is an evaluation reference. The evaluation of the coupling strength, as shown in Fig. 11, in the direction E of the extension line of the central portion 36a1, 36b1 of the connecting line and the reference high frequency coupler In a state in which the faces of the electrodes 150a of 150 are orthogonal and the central axes of the electrodes are aligned, the coupling electrode 37 is opposed to the electrode 150a, and the frequency characteristics of the coupling strength S21 are investigated with a gap of 15 mm and 100 mm therebetween. .

As described above, the central axis of the high-frequency coupler 30 is at a position which is approximately 1/4 of the length of the terminal 38a of the connection terminal 38, that is, a position corresponding to a length of 1/4 wavelength of the communication frequency. The position at which the terminal 38a is approximately 3/4 of the length of the reference, that is, the position corresponding to the length of the 3/4 wavelength of the communication frequency, is projected in the direction of the in-plane direction at a position on the surface of one half of the thickness of the dielectric substrate 31.

Further, in order to observe the state of generation 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 having a distance of 15 mm were also investigated.

Fig. 12 is a view showing the analysis result of the coupling strength S21 between the high frequency coupler 30 and the reference high frequency coupler 150. The communication distance of the opposite distance 15 mm has a good coupling strength of -18 dB around 4.5 GHz, and It has a communication blocking degree of -40 dB or less to a non-communication distance of 100 mm.

Fig. 13 is a view showing an analysis result of the electric field distribution of the high-frequency coupler 30 at a resonance frequency of 4.48 GHz. It is understood that two electric field strength portions are generated in the central axis direction of the central portions 36a1 and 36b1 of the connecting line, and act like an electric dipole. The opposing high frequency coupler 150 is electromagnetically coupled.

As can be seen from Fig. 13, the position at which the electric field becomes strong is at a position which is substantially 1/4 of the length of the coil 36 from the terminal 38a of the connection terminal 38, that is, a position corresponding to the length of the 1/4 communication wavelength and the position from the other terminal 38b. Coil 36 A position of approximately 1/4 of the length penetrates the positions in the in-plane direction to obtain strong electromagnetic field coupling.

As described above, the high frequency coupler 30 of the modification can achieve 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 achieved. Further, the high-frequency coupler 30 is extended to the line center portion 36b1 of the coil 36b which is connected to the coil 36a having a length of 1/2 of the communication wavelength and the line 36b of the coil 36b having a length of 1/2 of the communication wavelength. The electrode electromagnetic field of the other antenna device on the line is coupled, whereby the structure of the electromagnetic field is radiated in a direction perpendicular to the substrate surface, for example, in order to improve the communication performance, the dielectric substrate does not need to be thickened, and the device can be miniaturized and low at the same time. Highly.

Further, as is apparent from the analysis results shown in FIG. 14, the high-frequency coupler 30 can increase the effective inductance of the coil 36, and as a result, the coupling efficiency of the high-frequency coupler 30 itself can be improved.

Fig. 14 is a view showing an analysis result of the magnetic field vector distribution of the high-frequency coupler 30 at a resonance frequency of 4.48 GHz, which is shown in a plane parallel to the substrate in the center in the thickness direction of the dielectric substrate 31, that is, at the center axis of the coil 36 and the substrate level. The magnetic field vector distribution of the profile.

In this FIG. 14, the magnetic field inside the through coil 36 is shown to be in the same direction. The high-frequency coupler 30 considers the characteristic that the polarity of the high-frequency current at half-wavelength changes due to the phase relationship, so that the winding direction of the coil 36 whose total length corresponds to a communication wavelength is equivalent to 1/4 communication wavelength, 3/4, respectively. The central portions 36a1, 36b1 of the length of the communication wavelength are reversed, whereby the magnetic flux inside the coil 36 can be made The field becomes the same direction.

In the above manner, the high-frequency coupler 30 can prevent the magnetic fields generated by the currents having different local polarities from canceling each other inside the coil. Thereby, the high frequency coupler 30 can increase 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 of the first embodiment and the second embodiment can be assembled to the memory card 62 or the like because the entire device can be downsized and lowered in height. The memory card 62 can be assembled. For example, a slot 61 or the like provided in the end surface 60a of the portable electronic device 60 such as a mobile phone as shown in FIG. 15 is inserted for communication. Here, in the case where the high frequency coupler 10 is provided in the memory card 62 due to the positional relationship with the high frequency coupler provided inside the slot 61, the positional relationship is limited, but the first embodiment and the second embodiment Since the high-frequency couplers 10, 20, and 30 can simultaneously achieve miniaturization and low height of the entire device, they are easy to assemble.

10,20,30,102,106‧‧‧High frequency coupler

11,21,31,311‧‧‧ dielectric substrate

11a, 60a‧‧‧ end face

Line 12,312‧‧

12a, 26a1, 26b1, 36a1, 36b1‧‧ ‧ central line

12b, 12c‧‧‧ end

13,202,313‧‧‧ Grounding

14,314‧‧‧Power Supply Department

15‧‧‧Protective film

17,27,37,103,107,208‧‧‧coupled electrode

21a‧‧‧above

21b‧‧‧ below

23a, 33a‧‧‧ upper line

23b, 33b‧‧‧ below line

24,34‧‧‧through holes

26,26a,26b,36a,36b‧‧‧ coil

28,38‧‧‧Connecting terminal

38a, 38b‧‧‧ terminals

60‧‧‧Portable electronic machines

61‧‧‧ slots

62‧‧‧ memory card

100‧‧‧Communication system

101,105‧‧‧Communication device

104,108‧‧‧Transceiver Circuits Department

150‧‧‧reference high frequency coupler

150a‧‧‧electrode

201‧‧‧Printed substrate

203‧‧‧ cut line

205‧‧‧Transceiver circuit

207‧‧‧metal wire

300‧‧‧Antenna device

Fig. 1 is a view showing the configuration of a communication system in which an antenna device to which the present invention is applied is assembled.

Fig. 2 is a view showing a configuration of a high frequency coupler according to a first embodiment of the antenna device to which the present invention is applied.

Fig. 3 is a perspective view showing a communication state between the high frequency couplers in the high frequency coupler according to the first embodiment.

Figure 4 is a cross-sectional view showing the center of the high frequency coupler of the first embodiment. The electric field distribution map of the electric field analysis result.

Fig. 5 is a frequency characteristic diagram showing an analysis result of the coupling strength between the high-frequency coupler and the reference coupler of the first embodiment.

Fig. 6 is a view showing a configuration of a high frequency coupler according to a second embodiment of the antenna device to which the present invention is applied.

Fig. 7 is a perspective view showing a communication state between the high frequency couplers in the high frequency coupler of the second embodiment.

Fig. 8 is a view showing an electric field distribution of a result of electric field analysis at a center cross section in the high-frequency coupler of the second embodiment.

Fig. 9 is a frequency characteristic diagram showing an analysis result of the coupling strength between the high-frequency coupler and the reference coupler of the second embodiment.

FIG. 10 is a view showing a configuration of a high frequency coupler according to a modification of the second embodiment of the antenna device of the present invention.

Fig. 11 is a perspective view showing a communication state between the high frequency couplers in the high frequency coupler according to the modification of the second embodiment.

Fig. 12 is a frequency characteristic diagram showing an analysis result of the coupling strength between the high frequency coupler and the reference coupler according to the modification of the second embodiment.

Fig. 13 is a view showing an electric field distribution of a result of electric field analysis at a center cross section in a high-frequency coupler according to a modification of the second embodiment.

Fig. 14 is a view showing an analysis result of a magnetic field vector distribution of a high-frequency coupler according to a modification of the second embodiment.

Fig. 15 is a view for explaining a specific example of an electronic apparatus in which an antenna device to which the present invention is applied is assembled.

Fig. 16 is a view showing the configuration of a high frequency coupler of a conventional example.

Fig. 17 is a view showing the configuration of a high frequency coupler of a conventional example.

18A and 18B are views showing the configuration of a high frequency coupler of a conventional example.

10‧‧‧High frequency coupler

11‧‧‧Dielectric substrate

11a‧‧‧ end face

12‧‧‧ line

12a‧‧"Line Central

12b, 12c‧‧‧ end

13‧‧‧ Grounding

14‧‧‧Power Supply Department

15‧‧‧Protective film

17‧‧‧Coupling electrode

Claims (6)

An antenna device for performing information communication by electromagnetic field coupling between opposite counter electrodes by a predetermined communication wavelength, characterized in that it is formed on a dielectric substrate and coupled with an electrode electromagnetic field of another antenna device to become communicable a coupling electrode having a length of 1/2 of a communication wavelength, a first wiring formed on the dielectric substrate, and a central portion of the first wiring in a direction opposite to a surface of the dielectric substrate and electrically connected thereto The conductor of the first wiring is electromagnetically coupled to the electrode of the other antenna device disposed on the extension line connecting the central portion of the first wiring to the conductor. The antenna device according to claim 1, wherein the conductor is grounded on the same surface of the dielectric substrate as the first wiring; and the first wiring is formed by a predetermined distance formed by a predetermined distance outside the ground. The shape is configured such that one end thereof is electrically connected to the ground, and the other end is supplied with electric power as an input terminal of a power supply voltage based on the ground. The antenna device according to claim 1, wherein the conductor is a second wiring formed by a length of one half of the communication wavelength, and one end of the second wiring is electrically connected to one end of the first wiring; The electrode is electromagnetically coupled to an electrode of the other antenna device that is disposed on an extension line connecting the central portion of the first wiring to the central portion of the second wiring. The antenna device according to claim 3, wherein the first wiring and the second wiring are formed by a coil wound through a through hole in a lower surface of the dielectric substrate. The antenna device according to claim 4, wherein the first wiring and the second wiring are reversed in a winding direction of each of the central portions. A communication device for performing information communication by electromagnetic field coupling between opposite counter electrodes by a predetermined communication wavelength, characterized in that: a coupling electrode is formed on a dielectric substrate and coupled to an electrode electromagnetic field of another antenna device And the communication processing unit is electrically connected to the coupling electrode and performs signal transmission and reception processing; the coupling electrode has a length of 1/2 of a communication wavelength and is formed on one side of the dielectric substrate a wiring, a conductor that is electrically connected to the first wiring in a direction in which the central portion of the first wiring is opposed to the surface of the dielectric substrate, and another day that is disposed on an extension line connecting the central portion of the first wiring and the conductor Electromagnetic field coupling of the electrode of the line device.