JP2008109561A - Loop antenna, antenna substrate, antenna integrated module and communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarization-shared loop antenna which is small in size, thin in thickness and wide in band. <P>SOLUTION: The loop antenna includes: a planar antenna conductor including a band-like first opening and a second opening which crosses the first opening at 45° to 90° and of which one terminal is opened; and a power feeding circuit, for the antenna conductor, formed at an edge of the antenna conductor so as to be positioned on an extension of the first opening in a lengthwise direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a loop antenna, an antenna substrate, an antenna integrated module, and a communication device used for a wireless communication device such as a mobile phone, a wireless LAN, UWB (Ultra Wide Band), a television receiver, and other various communication devices. In particular, the present invention relates to a loop antenna, an antenna substrate, an antenna integrated module, and a communication device that are effective for broadband transmission / reception.

  A plate-like loop antenna shown in a plan view in FIG. 10 is known as a loop antenna for transmission / reception, in particular, as a broadband loop antenna used in wireless communication devices such as mobile phones and wireless LANs, and other various communication devices. ing. In FIG. 10, 111 is a planar antenna conductor having a band-shaped opening 112 in the center, and 121 is formed on the edge of the antenna conductor so as to be positioned on the extension of the opening 112 in the longitudinal direction (Y direction). This is a power feeding circuit.

  A broadband loop antenna 110 shown in FIG. 10 is obtained by expanding the conventional loop antenna 130 of a so-called one-wavelength linear conductor shown in FIG. In the loop antenna 130 shown in FIG. 11, the length of one round of the antenna conductor 131 resonates at a frequency corresponding to about one wavelength. The broadband loop antenna 110 shown in FIG. 10 can be regarded as including a plurality of one-wavelength linear conductor loop antennas having different one-round lengths in one planar antenna conductor. That is, in the loop antenna 110, the length of one round of the loop antenna of each one-wavelength linear conductor is from a relatively short length corresponding to the circumference of the opening 112 to the outer circumference of the antenna conductor 111. It has a range up to the corresponding relatively long one, and the frequency corresponding to the length also has a range and has a broadband characteristic. Since the current distribution is the same as that of the loop antenna 130 shown in FIG. 11, the loop antenna 110 can transmit and receive radio waves whose polarization is in the X direction, and the directivity is omnidirectional in the YZ plane. . At this time, a magnetic field penetrating the opening 112 is generated along the opening 112.

  However, the plate-like loop antenna 110 capable of transmitting and receiving a broadband as shown in FIG. 10 can transmit and receive radio waves whose polarization is in the X direction, but cannot transmit and receive radio waves whose polarization is in the Y direction. In mobile communication where the polarization of radio waves to be transmitted is not constant, the efficiency of transmission and reception of radio waves is poor.

  Therefore, as a method for enabling transmission and reception of two radio waves having different polarization directions, that is, as a polarization sharing technique, positions where the loop antenna 110 shown in FIG. 10 is rotated by 90 ° as shown in FIG. In relation, a method of arranging them in the parallel direction is known. According to the configuration of FIG. 12, the first loop antenna 110A can transmit and receive radio waves whose polarization is in the X direction, and the second loop antenna 110B can transmit and receive radio waves whose polarization is in the Y direction. It is possible to transmit and receive radio waves with polarized waves in both directions, that is, polarization sharing is possible.

As another polarization sharing method, the loop antenna 110 shown in FIG. 10 is connected to each other as shown in FIG. 13, as in the case of the loop antenna with a one-wavelength linear conductor (see, for example, Patent Document 1). There is known a method of arranging them vertically in a positional relationship rotated by 90 °. According to the configuration of FIG. 13, the first loop antenna 110A can transmit and receive radio waves whose polarization is in the X direction, and the second loop antenna 110B can transmit and receive radio waves whose polarization is in the Y direction. It is possible to transmit and receive radio waves of both directions of polarization, that is, to share polarization.
JP-A-10-126149

  However, when polarization sharing is performed with the configuration shown in FIG. 12, it is necessary to arrange two loop antennas in parallel, which increases the mounting area of the antenna and leads to an increase in the size of a device on which the loop antenna is mounted. To trigger.

  Further, when polarization sharing is performed with the configuration shown in FIG. 13, if the distance h between the first loop antenna 100 and the second loop antenna 200 is equal to or less than a half wavelength of the frequency to be used, the mutual antennas are Interference causes a problem that the antenna characteristics deteriorate. Further, in order to prevent deterioration of antenna characteristics, if the distance h between the first loop antenna 100 and the second loop antenna 200 is set to a half wavelength or more of the frequency to be used, the length (height) of the antenna in the vertical direction becomes large. This leads to the problem of increasing the size of the device equipped with the loop antenna.

  The present invention has been completed in view of the above problems, and an object of the present invention is to provide a small-sized and wide-band polarized-loop antenna, and an antenna substrate having such a loop antenna, an antenna integrated module, and It is to provide communication equipment.

  A first loop antenna according to the present invention is a planar antenna having a strip-shaped first opening and a second opening that intersects the first opening at an angle of 45 to 90 degrees and is open at one end. It is characterized by comprising a conductor and a feeding circuit for the antenna conductor formed at the edge of the antenna conductor so as to be positioned on the longitudinal extension of the first opening.

  In the first loop antenna, preferably, the antenna conductor has a square shape, and the second opening is a central portion in the longitudinal direction of the first opening with respect to the first opening. Intersect vertically.

  The second loop antenna of the present invention is a planar antenna having a strip-shaped first opening and a second opening that intersects the first opening at an angle of 45 to 90 degrees and is open at one end. A plurality of partial antenna conductors obtained by dividing the conductor in one direction and one edge portion of the plurality of partial antenna conductors are formed so as to be located on the extension line in the longitudinal direction of the first opening. A loop antenna including a feeding circuit for the antenna conductor, wherein the plurality of partial antenna conductors are arranged such that the antenna conductor is folded, and the respective planes adjacent to the plurality of opposed planar conductors The plurality of planar conductors are characterized in that the shapes of the openings in the planar conductors coincide when viewed through the plane.

  In the second loop antenna, preferably, in the plurality of partial antenna conductors, the second opening intersects the first opening perpendicularly at a central portion in the longitudinal direction of the first opening. It is obtained by dividing a square antenna conductor in one direction.

  The antenna substrate of the present invention is characterized in that any one of the above loop antennas is formed on the surface of the dielectric substrate or in the dielectric substrate.

  The first antenna-integrated module of the present invention is characterized in that a high-frequency circuit for converting a signal input from the outside into a high-frequency signal and outputting it to the power feeding circuit is mounted on the antenna substrate.

  In the first antenna-integrated module, preferably, the high-frequency circuit is mounted so as not to overlap the first and second openings when the antenna substrate is viewed in plan.

  In the second integrated antenna module of the present invention, in the first integrated antenna module, a signal processing circuit for processing an externally input signal and outputting the signal to the high frequency circuit is mounted on the antenna substrate. It is characterized by.

  In the second antenna-integrated module, preferably, the high-frequency circuit and the signal processing circuit are respectively mounted so as not to overlap the first and second openings when the antenna substrate is seen through the plane. Yes.

  The third antenna integrated module of the present invention is characterized in that, in the second antenna integrated module, a sensor module connected to the signal processing circuit is mounted on the antenna substrate.

  In the third integrated antenna module, it is preferable that the high-frequency circuit, the signal processing circuit, and the sensor module do not overlap the first and second openings when the antenna substrate is seen through the plane. It is installed.

  According to a fourth integrated antenna module of the present invention, in the third integrated antenna module, a power supply for supplying power to the high frequency circuit, the signal processing circuit, and the sensor module is mounted on the antenna substrate. It is characterized by.

  In the fourth antenna-integrated module, preferably, the high-frequency circuit, the signal processing circuit, the sensor module, and the power source are the first and second openings when the antenna substrate is seen through the plane. It is mounted so as not to overlap each other.

  A first communication device according to the present invention includes any one of the above loop antennas.

  A second communication device of the present invention is characterized in that the antenna substrate is mounted.

  A third communication device of the present invention is characterized in that any one of the antenna integrated modules is mounted.

  A loop antenna according to the present invention includes a planar antenna conductor having a first opening in a band shape, a second opening that intersects with the first opening at an angle of 45 to 90 degrees and one end is open, and an antenna. The antenna conductor has a plate-like shape as a whole since the antenna conductor includes a feeding circuit for the antenna conductor formed at the edge of the conductor so as to be positioned on the extension line in the longitudinal direction of the first opening. It has wideband characteristics. At the same time, a magnetic field that passes through the first opening is generated along the first opening, an electric field is generated in a direction perpendicular to the first opening, and a magnetic field that passes through the second opening along the second opening. And an electric field is generated in a direction perpendicular to the second opening. Therefore, it is possible to transmit and receive a polarized wave having an angle difference of 45 to 90 degrees from each other, and to share the polarization. In addition, since it is not necessary to use two antenna conductors having the same shape for polarization sharing, a small-sized polarization sharing antenna can be realized.

  Further, in the loop antenna, when the antenna conductor has a square shape and the second opening intersects the first opening at the center in the longitudinal direction of the first opening, the antennas are perpendicular to each other. Waves can be transmitted and received, allowing more efficient polarization sharing.

  The loop antenna of the present invention has a planar antenna conductor in one direction that has a strip-shaped first opening and a second opening that intersects the first opening at an angle of 45 to 90 degrees and is open at one end. A plurality of partial antenna conductors obtained by dividing the antenna into a plurality of partial antenna conductors and an antenna conductor feeding circuit formed on one edge of the plurality of partial antenna conductors so as to be positioned on an extension line in the longitudinal direction of the first opening The plurality of partial antenna conductors are arranged so that the antenna conductors are folded, and are composed of a plurality of opposing planar conductors and connecting conductors connecting the adjacent planar conductors, A plurality of planar conductors are characterized in that the shape of the opening in each planar conductor matches when seen through the plane. A. Further, since the plurality of partial antenna conductors are composed of a plurality of opposing planar conductors and connecting conductors connecting the adjacent planar conductors arranged so that the antenna conductors are folded, A plurality of opposing planar conductors overlap, and the area when viewed in plan can be kept small. In addition, when the plurality of planar conductors are seen through the plane, the shape of the opening in each planar conductor matches, so that the magnetic field generated through the first and second openings is blocked by each planar portion of the antenna conductor. Therefore, it is possible to transmit and receive polarized radio waves having an angle difference of 45 to 90 degrees.

  Further, in the loop antenna, the plurality of partial antenna conductors divide the square antenna conductor in which the second opening intersects perpendicularly at the center in the longitudinal direction of the first opening with respect to the first opening in one direction. Thus, it is possible to transmit and receive radio waves with polarized waves perpendicular to each other.

  The antenna substrate of the present invention is characterized in that the loop antenna according to any one of the above is formed on the surface of the dielectric substrate or in the dielectric substrate, so that the wavelength reduction effect due to the dielectric constant of the dielectric substrate is achieved. The size of the antenna can be reduced.

  The antenna integrated module according to the present invention is characterized in that a high-frequency circuit that converts a signal input from the outside into a high-frequency signal and outputs it to the power feeding circuit is mounted on the antenna substrate. Wiring to and from the circuit can be formed on the antenna substrate with the shortest path, and transmission loss of the high-frequency signal transmitted between the high-frequency circuit and the power feeding circuit can be reduced. Further, since the antenna substrate and the high frequency circuit can be integrated, the size of the module can be reduced.

  Further, in the antenna integrated module, when the high frequency circuit is mounted so as not to overlap the first and second openings when the antenna substrate is seen through, the gap between the high frequency circuit and the power feeding circuit can be reduced. This wiring can be formed on the antenna substrate with the shortest path, and transmission loss of a high-frequency signal transmitted between the high-frequency circuit and the power feeding circuit can be reduced. Further, since the antenna substrate and the high frequency circuit can be integrated, the size of the module can be reduced. Furthermore, the magnetic field generated through the first and second openings is not interrupted by the high frequency circuit, and deterioration of the antenna characteristics can be suppressed.

  Since the antenna integrated module of the present invention includes a signal processing circuit that processes an externally input signal and outputs the signal to a high frequency circuit in the antenna integrated module, the antenna substrate, the high frequency circuit, and Since the signal processing circuit can be integrated, the size of the module can be reduced.

  In the antenna integrated module, when the high frequency circuit and the signal processing circuit are mounted so as not to overlap the first and second openings when the antenna substrate is seen through the plane, the antenna substrate, the high frequency Since the circuit and the power feeding circuit can be integrated, the module can be reduced in size. Furthermore, the magnetic field generated through the first and second openings is not interrupted by the high frequency circuit and the signal processing circuit, and the deterioration of the antenna characteristics can be suppressed.

  The antenna integrated module of the present invention is characterized in that, in the above-mentioned antenna integrated module, a sensor module connected to the signal processing circuit is mounted on the antenna substrate, so that the antenna substrate, the high frequency circuit, and the signal processing circuit are mounted. Since the sensor module can be integrated, the module can be reduced in size.

  In the antenna integrated module, when the high-frequency circuit, the signal processing circuit, and the sensor module are mounted so as not to overlap the first and second openings when the antenna substrate is seen through the plane, The magnetic field generated through the first and second openings is not interrupted by the high-frequency circuit, the signal processing circuit, and the sensor module, and deterioration of the antenna characteristics can be suppressed.

  The antenna integrated module of the present invention is characterized in that, in the antenna integrated module, the antenna substrate is mounted with a power source for supplying power to the high frequency circuit, the signal processing circuit, and the sensor module. Since the antenna substrate, the high frequency circuit, the signal processing circuit, the sensor module, and the power source can be integrated, the module can be reduced in size.

  In the antenna integrated module, when the high frequency circuit, the signal processing circuit, the sensor module, and the power source are mounted so as not to overlap the first and second openings when the antenna substrate is seen through the plane, respectively. The magnetic field generated through the first and second openings is not blocked by the high-frequency circuit, the signal processing circuit, the sensor module, and the power source, and the deterioration of the antenna characteristics can be suppressed.

  Since the communication device of the present invention is characterized in that any one of the above loop antennas is mounted, it is possible to provide a communication device capable of small-sized communication with wide bandwidth and polarization sharing.

  The communication device according to the present invention is characterized in that the antenna substrate is mounted on the communication device. Therefore, it is possible to provide a communication device capable of further communication in a wide band and for polarization sharing.

  Since the communication device of the present invention is characterized in that any one of the above-described antenna integrated modules is mounted, it is possible to provide a communication device capable of further communication in a wide band and polarization sharing.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a plan view showing a configuration example of a loop antenna according to the first embodiment of the present invention. In FIG. 1, 10 is a loop antenna, 11 is a square-shaped opening having a strip-shaped first opening 12A and a second opening 12B that intersects the first opening 12A at an angle of 90 degrees and is open at one end. The antenna conductor 21 is a feeding circuit for the antenna conductor 11 formed so as to be positioned on the extended line in the longitudinal direction (Y direction) of the first opening 12A at the edge of the antenna conductor 11. Here, the two openings 12A and 12B have the same shape and dimensions.

  The power feeding circuit 21 functions as a supply terminal for supplying a current necessary for the antenna conductor 11 to transmit a predetermined radio wave. The power feeding circuit 21 also functions as a supply terminal for supplying a current generated by the radio wave received by the antenna conductor 11 to an external electric circuit.

  The openings 12A and 12B have a long and narrow shape such as a rectangular shape. The longitudinal direction of the openings 12A and 12B extends in the extending direction of the line segment that extends the longest from one point of the edge of the opening to the other point through the center of the opening 12. The direction of the central axis of the direction. The openings 12A and 12B are for causing the planar conductor to function as a loop antenna capable of transmitting and receiving. In order to obtain only the polarization component perpendicular to the longitudinal direction of the opening 12A and the polarization component perpendicular to the longitudinal direction of the opening 12B, the openings 12A and 12B are desirably provided in the central portion of the antenna conductor 11.

  Next, the characteristics of the loop antenna 11 according to the present embodiment will be described. Whether or not it can function as a broadband loop antenna can be verified by reflection characteristics (VSWR: Voltage Standing Wave Ratio). Devices that handle high-frequency signals are required to have this value as low as possible. Here, FIG. 2A is a graph showing the frequency characteristics of the VSWR of the loop antenna 10 according to the present embodiment, and FIG. 2B shows the frequency characteristics of the VSWR of the conventional loop antenna 110 shown in FIG. It is a graph. As shown in FIGS. 2A and 2B, the VSWR of the conventional loop antenna 110 and the VSWR of the loop antenna 10 according to the present embodiment show 2 or less over about 1.5 GHz centering on 4 GHz. It can be seen that the loop antenna 10 according to the present embodiment has a broadband characteristic comparable to that of the conventional loop antenna 110.

  3A is a graph showing average gains Gx and Gy of the X-direction and Y-direction polarizations of the loop antenna 10 according to the present embodiment, and FIG. 3B is a graph of the conventional loop antenna 110. It is a graph which shows the average gain Gx and Gy of a X direction and a Y direction polarization | polarized-light. In the graph of FIG. 3B, Gx is 0 dBi or more and Gy is 0 dBi or less, and it can be seen that the polarization of the conventional loop antenna 110 is in the X direction. On the other hand, in the graph of FIG. 4A, Gx is 0 dBi or more at 3 to 5 GHz, and Gy is 0 dBi or more at 3 to 4.5 GHz. As a result, according to the configuration of the loop antenna 10 according to the present embodiment, it is possible to transmit and receive polarized waves in both the X direction and the Y direction, particularly in the frequency band of 3 to 4.5 GHz, and realize polarization sharing. I understand.

  As described above, the loop antenna 10 according to the present embodiment has a low VSWR and can realize polarization sharing in the frequency band of 3 to 5 GHz. Therefore, since the loop antenna 10 according to Embodiment 1 has excellent characteristics in the frequency band (3 to 5 GHz) used in UWB communication, it can be applied as an antenna for UWB communication.

  The loop antenna 10 described above includes the square antenna conductor 11 having the two orthogonal openings 12A and 12B. However, the shape of the antenna conductor 11 is not limited to this as long as it is planar. Further, the openings 12A and 12B provided in the antenna conductor 11 do not necessarily intersect perpendicularly, and one opening 12A and 12B only needs to intersect with the other opening 12B and 12A at an angle of 45 to 90 degrees. . Further, the two openings 12A and 12B do not have to have the same shape and size, and at least one of the shape and size may be different.

  The loop antenna 10 according to the first embodiment has a planar first opening 12A and a second opening 12B that intersects the first opening 12A at an angle of 45 to 90 degrees and is open at one end. The antenna conductor 11 and the antenna conductor feeding circuit 21 formed on the edge of the antenna conductor 11 so as to be positioned on the extension line in the longitudinal direction of the first opening 12A are provided. With this configuration, the antenna conductor 11 is plate-shaped as a whole, and thus has a wide band characteristic. That is, the antenna conductor 11 can be regarded as being composed of a plurality of one-wavelength linear conductors, and the length of one circumference of the one-wavelength linear conductor is relatively short that hits the periphery of the opening 12A. Since it has a range up to a relatively long one corresponding to the outer edge portion, the frequency corresponding to the length also has a range and can have a broadband characteristic. At the same time, since a magnetic field that penetrates the first opening 12A is generated along the first opening 12A, an electric field is generated in a direction perpendicular to the first opening 12A, and the second opening 12B is A magnetic field is generated through the opening 12B, and an electric field is generated in a direction perpendicular to the second opening 12B. Therefore, it is possible to transmit and receive a polarized wave having an angle difference of 45 to 90 degrees from each other, and to share the polarization. In addition, since it is not necessary to use two antenna conductors having the same shape for polarization sharing, a small-sized polarization sharing antenna can be realized.

(Second Embodiment)
FIG. 4 is a perspective perspective view showing a configuration example of a loop antenna according to the second embodiment of the present invention, and FIG. 5 is a plan view of a plate-like loop antenna serving as a basic structure of the loop antenna shown in FIG. It is. In addition, the basic structure in this case means the structure which becomes a loop antenna shown in FIG. 4 by being folded.

  As shown in FIGS. 4 and 5, the loop antenna 30 includes a planar antenna conductor 31 including a plurality of partial antenna conductors 31T, 31B, and 31S. The antenna conductor 31 has a first opening 32A and a second opening 32B that intersects the first opening 32A at an angle of 90 degrees and is open at one end. The first opening 32A includes an opening 32AT located in the partial antenna conductor 31T and an opening 32AB located in the partial antenna conductor 31B, and the second opening 32B includes the opening 32BT located in the partial antenna conductor 31T and a portion thereof. It consists of an opening 32BB located in the antenna conductor 31B. Furthermore, the loop antenna 30 includes a feeding circuit 41 for the antenna conductor 11 formed so as to be positioned on the extension line in the longitudinal direction of the first opening 12A at the edge of the partial antenna conductor 31T. The openings 32A and 32B have the same shape and dimensions.

  As shown in FIG. 4, the antenna conductor 31 is connected so as to connect the partial antenna conductors 31T and 31B adjacent to the adjacent partial antenna conductors 31T and 31B, which are arranged so that the antenna conductor 31 is folded. It consists of a conductor 31S. Further, the plurality of partial antenna conductors 31T and 31B are arranged so that the shapes of the openings in the partial antenna conductors 31T and 31B coincide when viewed in plan. That is, in the example shown in FIG. 5, the shapes of the opening 32AT and the opening 32BB and the shapes of the opening 32BT and the opening 32AB are the same. Here, the partial antenna conductors 31T and 31B each form a planar conductor, and the partial antenna conductor 31S serves as a connection conductor that connects adjacent planar conductors.

  The loop antenna 30 according to the present embodiment has a wide band characteristic because the antenna conductor 11 as a basic structure is plate-like as a whole. That is, the antenna conductor 31 can be regarded as consisting of a plurality of one-wavelength linear conductors, and the length of one circumference of the one-wavelength linear conductor is relatively equivalent to the length around each of the openings 32A and 32B. Since it has a range from a short one to a relatively long one corresponding to the length of the outer periphery of the antenna conductor 31, the frequency corresponding to the length also has a range and has a wide band characteristic. be able to. Further, the antenna conductor 31 includes a plurality of opposing partial antenna conductors 31T and 31B and a connection conductor 31S that connects the adjacent partial antenna conductors 31T and 31B, which are arranged so that the antenna conductor 11 is folded. When viewed in plan, the partial antenna conductors 31T and 31B overlap, and the area when viewed in plan can be kept small. In addition, the plurality of partial antenna conductors 31T and 31B are generated through the first and second openings 32A and 32B because the shapes of the openings in the partial antenna conductors 31T and 31B match when viewed in plan. The magnetic field is not interrupted by the planar portions 31T and 31B of the antenna conductor 11, and it is possible to transmit and receive polarized radio waves having an angle difference of 45 to 90 degrees.

  The loop antenna shown in FIG. 4 has been described as a loop antenna shown in FIG. 5 folded for convenience. However, the antenna conductor 31 formed in a flat shape is not necessarily folded once. It does not have to be applied and formed. For example, a plurality of planar conductors 31T and 31B produced individually may be formed by being electrically and mechanically connected via the connection conductor 31S.

  Next, characteristics of the loop antenna 30 according to the second embodiment will be described. FIG. 6 is a graph showing the frequency characteristics of VSWR of the loop antenna 30 according to the second embodiment. In FIG. 6, although VSWR is shifted to a lower frequency side than 4 GHz, it shows 3 or less from 2.5 GHz to 4 GHz, and it can be seen that it has a broadband characteristic.

  FIG. 7 is a graph showing the average gains Gx and Gy of the polarization in the X direction and the Y direction of the loop antenna 30 according to the present embodiment. In the graph of FIG. 7, Gx is about 0 dBi at 3 to 5 GHz, and Gy is 0 dBi or more at 3 to 3.5 GHz. Thus, it can be seen that the configuration of the loop antenna 30 according to the second embodiment makes it possible to transmit and receive polarized waves in both the X direction and the Y direction, and realize polarization sharing.

  As described above, the loop antenna 30 according to the present embodiment has a low VSWR and can realize polarization sharing in the frequency band of 3 to 5 GHz. Therefore, the loop antenna 30 according to the second embodiment can be applied as an antenna for UWB communication.

  In addition, although the above-mentioned loop antenna 30 has the square-shaped antenna conductor 31 which has two opening 32A, 32B orthogonal, the shape of the antenna conductor 31 is not restricted to this. Further, the openings 32A and 32B provided in the antenna conductor 31 do not necessarily intersect perpendicularly, and one opening 32A and 32B only needs to intersect with the other opening 32B and 32A at an angle of 45 to 90 degrees. .

  As described above, a planar antenna conductor having a strip-shaped first opening and a second opening that intersects the first opening at an angle of 45 to 90 degrees and is open at one end is divided in one direction. A plurality of partial antenna conductors obtained, and a feeding circuit for the antenna conductor formed on one edge of the plurality of partial antenna conductors so as to be positioned on the longitudinal extension of the first opening. The plurality of partial antenna conductors are arranged such that the antenna conductors are folded, and are composed of a plurality of opposing planar conductors and connecting conductors connecting the adjacent planar conductors. Planar conductors have wideband characteristics by matching the shape of the openings in each planar conductor when viewed in plan, and when viewed in plan when a plurality of opposing planar conductors overlap. Area of It can be reduced, also possible to realize a loop antenna capable of transmitting and receiving radio waves polarized wave having an angular difference of 45 to 90 degrees from each other.

  Further, the loop antennas 10 and 30 described above may be configured on the exposed surface or inside of a dielectric substrate (not shown), and the size of the antenna can be reduced by the wavelength shortening effect due to the dielectric constant of the dielectric substrate. Can do. At that time, the dielectric substrate and the antenna conductors 11 and 31 may be made of various materials used for the following high-frequency wiring substrate.

  For example, as a dielectric (insulator) material for a dielectric substrate, for example, ceramic materials such as alumina ceramics (alumina sintered body), mullite ceramics, inorganic materials such as glass ceramics, or tetrafluoroethylene-ethylene resin ( Polytetrafluoroethylene (PTFE), tetrafluoroethylene-ethylene copolymer resin (tetrafluoroethylene-ethylene copolymer resin; ETFE), tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin (tetrafluoroethylene-perfluoroalkyl) Fluorine resin such as vinyl ether copolymer resin (PFA), glass epoxy resin, resin material such as polyimide, or the like is used. In addition, the shape and dimensions (thickness, width, length) of the dielectric substrate are set according to the frequency and application of the high-frequency signal used.

The antenna conductors 11 and 31 are conductor layers made of a metal material for high-frequency signal transmission, such as a Cu layer, a Mo—Mn metallization layer, and a Ni plating layer and an Au plating layer deposited thereon, and a W metallization. Ni plating layer and Au plating layer deposited on the layer, Cr—Cu alloy layer, Ni plating layer and Au plating layer deposited on the Cr—Cu alloy layer, Ta ₂ N layer Ni-Cr alloy layer and Au plating layer deposited, Ti layer with Pt layer and Au plating layer deposited, or Ni-Cr alloy layer with Pt layer and Au plating layer deposited These are formed by using a thick film printing method, various thin film forming methods, plating methods, or the like.

  In this way, when a loop antenna is configured on a dielectric substrate, a high-frequency circuit connected to a power feeding circuit can be mounted on the dielectric substrate, which is effective for further downsizing and lowering the height of communication equipment. It is.

  For example, when the loop antennas 10 and 30 are formed on the surface or inside of a dielectric substrate made of glass ceramic, the loop antennas 10 and 30 are manufactured as follows. First, a glass ceramic green sheet formed by forming an unfired glass ceramic into a sheet is prepared. Thereafter, a pattern of a conductor paste layer that becomes the antenna conductors 11 and 31 is printed and applied by a screen printing method. Next, baking is performed at 850 to 1000 ° C., and finally Ni plating and Au plating are performed on the exposed surface of each conductor layer.

  Further, the openings 12A, 12B, 32A, 32B, for example, when the antenna conductors 11, 31 are formed by printing a conductor paste, non-printing portions corresponding to the openings 12A, 12B, 32A, 32B are formed on the printing plate making. It can be formed by providing. Alternatively, after a conductor pattern is printed once in a rectangular pattern or the like, the outer edge portion thereof is ground by laser processing or mechanical processing to form openings 12A, 12B, 32A, and 32B having a predetermined pattern. .

  By mounting this loop antenna as a device for transmission and reception, a wireless communication device such as a mobile phone, a wireless LAN, and a television, and other various communication devices are manufactured.

  According to this communication device, since the loop antenna of the present invention is mounted, an antenna conductor for polarization sharing is not necessary, and a small communication device can be provided.

  FIG. 9 is a block diagram showing an example of the antenna integrated module of the present invention. FIG. 10 is a plan view showing a configuration example of the antenna integrated module shown in FIG. FIG. 9 shows a configuration example of an antenna integrated module having the loop antenna 10 shown in FIG. In the antenna integrated module shown in FIGS. 8 and 9, data such as the attitude of the communication device and the external temperature sensed by the sensor module is sent to the signal processing circuit. The signal processing circuit processes the data output from the sensor module, and then outputs the processing result to the high frequency circuit. The high frequency circuit converts the data output from the signal processing circuit into a high frequency signal and outputs it to the antenna. The antenna outputs the input high frequency signal as a radio wave. The power supply supplies power to the high-frequency circuit, the signal processing circuit, and the sensor module, respectively.

  In the antenna integrated module shown in FIG. 8, the high frequency circuit, the signal processing circuit, the sensor module, and the power source are mounted so as not to overlap the two openings 12A and 12B when the antenna substrate 11 is seen through the plane. The magnetic field generated through the two openings 12A and 12B is not interrupted by the high-frequency circuit, the signal processing circuit, the sensor module, and the power source, and deterioration of the antenna characteristics can be suppressed.

  In addition, this invention is not limited to the example of the said embodiment, A various change can be given if it is in the range of the summary of this invention.

  For example, the antenna conductor 11 and the opening 12 may have a rectangular shape or an elliptical shape, and may have a structure that matches the housing shape of the device.

It is a top view which shows the structural example of the loop antenna by Embodiment 1 of this invention. (A) is a graph which shows the frequency characteristic of VSWR of the loop antenna by Embodiment 1, (b) is a graph which shows the frequency characteristic of VSWR of the conventional loop antenna shown in FIG. (A) is a graph which shows the average gains Gx and Gy of the X direction and Y direction polarization | polarized-light of the loop antenna by Embodiment 1, (b) is a X direction and Y of the conventional loop antenna shown in FIG. It is a graph which shows the average gains Gx and Gy of a directional polarization. It is a perspective perspective view which shows the structural example of the loop antenna by Embodiment 2 of this invention. It is a top view of the plate-shaped loop antenna used as the basic structure of the loop antenna shown in FIG. 6 is a graph showing the frequency characteristics of the VSWR of the loop antenna according to the second embodiment. It is a graph which shows the average gains Gx and Gy of the X direction of a loop antenna by this Embodiment 2, and a Y direction polarization | polarized-light. It is a block diagram which shows an example of the antenna integrated module of this invention. It is a top view which shows the structural example of the antenna integrated module shown by FIG. It is a top view which shows the structural example of the conventional 1st loop antenna. It is a top view which shows the structural example of the conventional 2nd loop antenna. It is a top view which shows the conventional 1st polarization sharing antenna. It is a see-through | perspective perspective view which shows the conventional 2nd polarization sharing antenna.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Loop antenna 11 ... Antenna conductor 12A ... 1st opening 12B ... 2nd opening 21 ... Feeding circuit

Claims (16)

A planar antenna conductor having a strip-shaped first opening and a second opening that intersects the first opening at an angle of 45 to 90 degrees and is open at one end; and at the edge of the antenna conductor And a feeding circuit for the antenna conductor, which is formed so as to be located on an extension line in the longitudinal direction of the first opening. 2. The antenna conductor according to claim 1, wherein the antenna conductor has a square shape, and the second opening intersects the first opening perpendicularly at a central portion in a longitudinal direction of the first opening. Loop antenna. A planar antenna conductor having a strip-shaped first opening and a second opening that intersects the first opening at an angle of 45 to 90 degrees and is open at one end is obtained by dividing the planar antenna conductor in one direction. A plurality of partial antenna conductors, and a feeding circuit for the antenna conductors formed at one edge of the plurality of partial antenna conductors so as to be positioned on an extension line in the longitudinal direction of the first opening. The plurality of partial antenna conductors are arranged such that the antenna conductors are folded, and are composed of connecting conductors connecting the adjacent planar conductors to the opposing planar conductors, The loop antenna, wherein the plurality of planar conductors have the same shape of an opening in each planar conductor when seen through the plane. The plurality of partial antenna conductors are obtained by dividing a square antenna conductor in which the second opening perpendicularly intersects with the first opening at a central portion in the longitudinal direction of the first opening in one direction. The loop antenna according to claim 3, wherein the loop antenna is provided. An antenna substrate comprising the loop antenna according to any one of claims 1 to 4 formed on or in a dielectric substrate surface. 6. An antenna integrated module comprising: the antenna substrate according to claim 5; and a high-frequency circuit that converts a signal input from the outside into a high-frequency signal and outputs the signal to the power feeding circuit. The antenna integrated module according to claim 6, wherein the high-frequency circuit is mounted so as not to overlap the first and second openings when the antenna substrate is seen through the plane. The antenna integrated module according to claim 6, wherein a signal processing circuit that processes a signal input from the outside and outputs the signal to the high-frequency circuit is mounted on the antenna substrate. 9. The integrated antenna according to claim 8, wherein the high-frequency circuit and the signal processing circuit are respectively mounted so as not to overlap the first and second openings when the antenna substrate is seen through in plan. module. The antenna integrated module according to claim 8, wherein a sensor module connected to the signal processing circuit is mounted on the antenna substrate. The high-frequency circuit, the signal processing circuit, and the sensor module are mounted so as not to overlap the first and second openings, respectively, when the antenna substrate is seen through in plan view. Integrated antenna module. The antenna integrated module according to claim 10, wherein a power supply for supplying power to the high-frequency circuit, the signal processing circuit, and the sensor module is mounted on the antenna substrate. The high-frequency circuit, the signal processing circuit, the sensor module, and the power source are mounted so as not to overlap the first and second openings, respectively, when the antenna substrate is seen through the plane. The antenna integrated module according to claim 12. A communication device comprising the loop antenna according to any one of claims 1 to 4. A communication device comprising the antenna substrate according to claim 5 mounted thereon. 14. A communication device comprising the antenna integrated module according to claim 6 mounted thereon.

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