JP2014030068A - Wireless device and mobile unit provided with wireless device - Google Patents

Abstract

Provided is a wireless device in which an antenna device and a wireless device are integrally configured to improve the appearance by wiring and to reduce the size of the device.
A wireless device of the present invention includes a two-dimensionally provided flat antenna 201 and a first housing 103 that accommodates a wireless device connected to the antenna 201. The antenna 201 is arranged along the surface (wall surface) of the first housing 103 on a plane. Thus, the antenna 201 is integrated in the wireless device along the surface of the first housing 103 that accommodates the wireless device. As a result, it is possible to eliminate the poor appearance caused by routing the wiring connecting the antenna 201 and the wireless device, and it is possible to reduce the size of the wireless device.
[Selection] Figure 1

Description

  The present invention mainly relates to a radio apparatus mounted on a moving body such as an automobile.

  For example, in the field of antennas for wireless devices mounted on automobiles (hereinafter referred to as vehicle-mounted antennas), various antennas adapted to various use frequency bands have been developed due to the recent development of communication networks.

  As an example, car navigation systems include GPS (Global Positioning System), VICS (Vehicle Information and Communication System) and ETC (Electronic Toll Collection System). Various antennas capable of transmitting and receiving microwaves of 1 GHz to 10 GHz used in ITS (Intelligent Transport Systems) are connected.

  Further, it is common that a car navigation system is integrally equipped with a tuner that receives not only the ITS but also radio broadcasts and terrestrial digital broadcasts. Therefore, the frequency band used for the vehicle-mounted antenna includes the AM frequency of 526.5 kHz to 1606.5 kHz, the VHF frequency of 60 MHz band or 87.5 MHz to 108 MHz, or, in recent years, three large areas of Kanto, Kinki, and Chukyo. The UHF frequency (470 MHz to 770 MHz) of terrestrial digital broadcasting whose service has been started in the service area is also included and covers a wide range.

  In the above terrestrial digital broadcasting, it is possible to provide interactive programs in addition to digital high-definition high-definition and high-quality programs, and even TVs installed on trains and buses that are running are flicker-free and beautifully displayed. It becomes possible to watch. In addition, services for receiving and viewing moving images, data broadcasting, and audio broadcasting with portable information terminals and the like are also planned.

  As an in-vehicle antenna, for example, the antennas disclosed in Patent Documents 1 to 4 can be cited.

  Patent Document 1 discloses an automobile antenna 1000 including a rod-shaped helical coil antenna 1001 provided outside the vehicle, as shown in FIG. The helical coil antenna 1001 is connected to a power supply cord 1003 via a circuit board 1002 as a power supply unit. The power supply cord 1003 is drawn into the vehicle and connected to a wireless device (not shown) in the vehicle.

  Patent Document 2 discloses a film-like antenna 1100 attached to a windshield 1101 of an automobile as shown in FIG. The antenna 1100 is connected to the navigation device 1102 via a power feeding unit (not shown).

  Patent Document 3 discloses an in-vehicle planar antenna 1200 attached to the surface of a dashboard 201 of an automobile as shown in FIG. This in-vehicle planar antenna 1200 is connected to a navigation device (not shown) via a power feeding cable 1202.

  Patent Document 4 discloses an antenna unit 1300 in which a helical antenna 1301 and a GPS antenna 1302 are formed on a printed circuit board 1303 as shown in FIGS. The helical antenna 1301 and the GPS antenna 1302 are connected to a system main body (not shown) via a cable 1304.

JP 2000-295017 A (released on October 20, 2000) JP 2006-80999 A (published March 23, 2006) JP 2009-272821 A (published on November 19, 2009) JP-A-10-56325 (published February 24, 1998)

  However, since all of Patent Documents 1 to 3 are installed at positions where the antenna device and the wireless device are separated from each other, the wiring for connecting the antenna device and the wireless device becomes long, and the loss due to the wiring is large. In addition, there is a problem that the installation work is necessary because wiring is necessary, and the cost is further increased, and the appearance is poor.

  On the other hand, according to the antenna device disclosed in Patent Document 4, since it can be integrally connected to a wireless device, there is no problem with wiring as in Patent Documents 1 to 3.

  However, the antenna device disclosed in Patent Document 4 includes an antenna unit 1300 in which a helical antenna 1301 and a GPS antenna 1302 are formed on a printed circuit board 1303 as shown in FIGS. Therefore, it is thicker than a general planar antenna.

  Therefore, when the antenna device and the wireless device disclosed in Patent Document 4 are integrally connected, there arises a problem that the entire device becomes very large.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to integrally form the antenna device and the wireless device so that the appearance due to wiring is not deteriorated, and the device It is an object of the present invention to provide a wireless device capable of reducing the size of the apparatus.

  The wireless device of the present invention is a wireless device including a flat radiating element in which conductive paths are two-dimensionally arranged and a wireless device connected to the radiating element via a feeder line. It is characterized in that the plane of the element is arranged along the wall surface of the wireless device.

  Here, the wall surface of the wireless device includes, for example, a wall surface of a housing that houses the wireless device body, a wall surface of a cover that covers the wireless device body, and the like.

  Therefore, according to said structure, since the plane of a radiation element is distribute | arranged so that the wall surface of a radio | wireless apparatus may be followed, a radio | wireless apparatus and a radiation element can be arrange | positioned closely. As a result, the wireless device and the radiating element are integrated in the wireless device. Here, if a flexible member is used as the support member for supporting the radiating element, even if the wall surface is curved, it is possible to follow the curved surface.

  In this way, if the wireless device and the radiating element are integrated, it is possible to eliminate poor visual appearance caused by routing the wiring (feeding line) connecting the radiating element and the wireless device, and Therefore, the size of the wireless device can be reduced.

  Furthermore, since the wiring connecting the radiating element and the wireless device can be shortened, the loss due to the wiring is reduced, and as a result, the wiring used can be reduced, or the impedance of the transmission line between the radiating element and the transmission / reception circuit can be reduced. There is an effect that there is no need to consider.

  If the wiring can be made thin in this way, the device can be further downsized.

  Note that the wireless device of the present invention may be used for transmission / reception, transmission-only, or reception-only. In addition, the “two-dimensionally arranged planar” plane is not limited to a two-dimensional plane, but is a three-dimensional shape obtained by cutting out a part of a curved surface such as a cylindrical surface, a spherical surface, a paraboloid, or a hyperboloid. It may be a plane having a shape.

  The radiating element includes a first root portion having a predetermined length from one end of the conductive path, a second root portion having a predetermined length from the other end of the conductive path, and the first root portion. And an intermediate portion that relays between the first root portion and the second root portion, and at each tip region of the first and second root portions, a feed portion connected to a feed line is formed. Preferably, a meander-shaped conductive path having a folding pattern of at least two times is formed.

  According to the above configuration, since the radiating element is hardly affected by the conductive member such as metal, the radiating element can be disposed close to the conductive member such as metal.

  Therefore, it is possible to arrange the radiating element in the vicinity of the metal casing that accommodates the wireless device, and the wireless device and the radiating element can be easily integrated, so that the size of the wireless device can be easily reduced. .

  The radiating element is preferably provided with a short-circuit portion that short-circuits the meander-shaped conductive path.

  According to the above configuration, by forming at least one short-circuit portion that short-circuits the conductive path, the number of conductive paths having different lengths can be increased, so that the resonance point of the antenna can be increased. The usable frequency band of the antenna device including the radiating element can be further expanded.

  In this case, when arranging one or a plurality of short-circuit portions for generating a short-circuit portion on the meander-shaped conductive path, the resonance point of the antenna is increased or the resonance point of the antenna is increased. The position and location where the short-circuit portion is arranged can be determined so as to reduce the VSWR value in the use band.

  In the radiating element, the first and second root portions provided on one end side and the other end side of the conductive path are formed with a winding portion surrounding the power feeding portion, and further, the first and second It is preferable that a wide portion having a wide width of the conductive path is formed in at least one of the two base portions.

  As a result, impedance matching between the radiating element and the feeder line in the power feeding unit is realized, and by doing so, the VSWR value of the radiating element can be reduced, that is, the VSWR characteristic can be improved.

  For this reason, since the VSWR characteristic can be improved while realizing a high radiation gain of the radiating element, the usable frequency band of the radiating element can be expanded.

  The radiating element is preferably a single line continuous from one end to the other end.

  According to the above configuration, in a radiating element having a conductive path continuous from one end to the other end, a high radiation gain can be realized in the same manner as a loop antenna having a loop shape by forming a feeding portion on both ends thereof. Can do.

  In addition, since the radiating element can have a loop shape, the conductive path can be provided two-dimensionally. That is, an antenna including a radiating element can be a planar antenna structure.

  Since such a planar antenna can be arranged in parallel to the metal surface of the metal housing that accommodates the wireless device, the increase in the thickness of the device by the antenna disposed along the wireless device is minimized. can do.

  In addition, since the conductive path of the antenna has a meander shape as described above, it is difficult to be affected by the metal casing that accommodates the wireless device, and a decrease in antenna performance can be suppressed.

  The radiating element may be arranged along a wall surface formed of a conductive material.

  It is preferable that the radiating element is held at least 2 mm apart from a wall surface formed of a conductive material.

  According to the above configuration, since the radiating element is separated from the conductor surface, the radiating element is hardly affected by the conductor surface, and the VSWR value in the use band of the antenna including the radiating element is reduced. be able to.

  Moreover, since the radiating element is held at least 2 mm away from the conductor surface, a usable frequency band in which the VSWR value is suppressed to 3.5 or less can be developed even when the antenna is mounted near the conductor. .

  It is preferable that a non-shielding space is formed on the side opposite to the wall surface of the radiating element held along the wall surface formed of the conductive material.

  According to the above configuration, the non-shielding space is formed on the side opposite to the wall surface of the radiating element held along the wall surface formed of the conductive material, so that radio waves are transmitted to the radiating element. Since it can be wound around, the performance of the antenna is not deteriorated.

  The flat radiation element may be embedded in a wall surface formed of an insulating material or fixed along the wall surface.

  The wall surface may include a curved surface to which a curvature having a curvature radius of 5 mm or more is provided, and the flat plate-shaped radiating element may be arranged along the curved surface.

  According to the above configuration, the radiating element can be arranged along the wall surface of the wireless device at various positions, for example, at the boundary between the upper surface and the side surface as well as on the plane of the housing formed of metal or dielectric material. When a certain edge portion is rounded, it is possible to arrange the edge portion from the upper surface to the side surface, so that the degree of freedom of arrangement of the radiating elements is increased. As a result, the degree of freedom in designing the entire wireless device is increased.

  In addition, since the curved surface has a curvature with a curvature radius of 5 mm or more, the antenna characteristics can be maintained when the radiating element is arranged along the wall surface of the wireless device. That is, when the curvature radius is smaller than 5 mm, it is difficult to maintain the antenna characteristics.

  The wireless device preferably includes a transmission / reception circuit connected to the radiating element, and the radiating element and the transmission / reception circuit are preferably arranged on the same plane.

  According to said structure, thickness reduction of the radio | wireless apparatus further provided with the transmission / reception circuit can be achieved. In addition, the conductive path connecting the radiating element and the transmission / reception circuit can be made shorter as compared with the configuration in which the radiating element and the transmission / reception circuit are arranged on different surfaces. There is no need to consider impedance.

  The wireless device may include at least two of the radiating elements.

  According to the above configuration, since at least two radiating elements are arranged, a signal can be received by selecting a radiating element with good reception sensitivity. Therefore, the reception sensitivity of the wireless device can be improved.

  You may make it mount the radio | wireless apparatus of this invention in a moving body.

  Here, examples of the moving body mainly include vehicles (automobiles, trains, etc.), airplanes, ships, and the like. Note that the above moving body may be called a mobile machine that requires power for movement.

  For example, when the moving body is an automobile, a car navigation device and a terrestrial digital wave tuner can be considered as the wireless device.

  Moreover, the mobile body provided with the said radio | wireless apparatus is also contained under the category of the present invention.

  The wireless device of the present invention is a wireless device including a flat radiating element in which conductive paths are two-dimensionally arranged and a wireless device connected to the radiating element via a feeder line. By arranging the plane of the element along the wall surface of the wireless device, the wireless device and the radiating element are integrated in the wireless device. As a result, it is possible to eliminate the poor appearance caused by routing the wiring connecting the radiating element and the wireless device, and it is possible to reduce the size of the wireless device.

It is a back perspective view of the vehicle equipment provided with the radio equipment concerning an embodiment of the invention. It is a front view of the vehicle equipment shown in FIG. It is a figure which shows the AA arrow line end surface in the vehicle equipment shown in FIG. (A) (b) is a figure which shows the modification of the connection of the antenna and housing | casing which are shown in FIG. It is a schematic block diagram which shows the circuit structure of the vehicle equipment shown in FIG. It is a top view which shows schematic structure of the antenna which concerns on embodiment of this invention. It is a schematic diagram which shows the state which has arrange | positioned the short circuit member in the radiation element which has a meander shape, and produced the some electroconductive path | route in the radiation element. It is a schematic diagram explaining the measurement condition of the experiment for showing the effect of the antenna apparatus of this invention. It is a top view which shows schematic structure of the comparative example of the antenna which concerns on embodiment of this invention. 10 is a graph showing VSWR characteristics of the antennas of FIGS. 6 and 9. It is a graph which shows the VSWR characteristic of the antenna apparatus provided with the antenna of FIG. 6 when changing the thickness of a dielectric material. 7 is a graph showing a radiation pattern of the antenna of FIG. 6, wherein (a) shows a radiation pattern on the xy plane, (b) shows a radiation pattern on the yz plane, and (c) shows a radiation pattern on the zx plane. . It is a top view which shows schematic structure of the modification of the antenna which concerns on embodiment of this invention. It is a top view which shows schematic structure of the comparative example of the modification of the antenna which concerns on embodiment of this invention. It is a top view which shows schematic structure of the comparative example of the modification of the antenna which concerns on embodiment of this invention. FIG. 16 is a graph showing VSWR characteristics of the antennas of FIGS. 13, 14 and 15. FIG. It is a graph which shows the VSWR characteristic of the antenna apparatus provided with the antenna of FIG. 13 when changing the thickness of a dielectric material. 14 is a graph showing a radiation pattern of the antenna of FIG. 13, wherein (a) shows a radiation pattern on the xy plane, (b) shows a radiation pattern on the yz plane, and (c) shows a radiation pattern on the zx plane. . It is a top view which shows schematic structure of the other modification of the antenna which concerns on embodiment of this invention. It is a figure which shows the modification of the attachment structure of an antenna, (a) shows the example which provided the antenna in the surface of the insulating cover provided in the outer side of the 1st housing | casing, (b) shows the antenna 1st The example provided in the back surface of the insulating cover provided in the outer side of the housing | casing is shown. It is a figure which shows the example which attached two antennas to the 1st housing | casing. It is a figure which shows the example at the time of forming the antenna and the transmission / reception circuit of a radio | wireless apparatus on the same plane. It is a schematic diagram explaining the specific example of a mounting location in the case of mounting the radio | wireless apparatus of this invention in a vehicle. It is a figure which shows the attachment structure of the conventional antenna. It is a figure which shows the attachment structure of the conventional antenna. It is a figure which shows the attachment structure of the conventional antenna. It is a figure which shows the structure of the conventional antenna, (a) is sectional drawing, (b) is a top view.

  An embodiment of the present invention will be described as follows. Here, an in-vehicle device housed in an instrument panel (hereinafter referred to as an instrument panel) of an automobile will be described as a wireless device of the present invention.

(Description of onboard equipment with integrated antenna)
FIG. 1 is a schematic perspective view of the in-vehicle device 100 according to the present embodiment as viewed from the inside of the instrument panel.

  FIG. 2 is a front view of the in-vehicle device 100 shown in FIG. 1 from the outside of the instrument panel.

  As shown in FIG. 1, the in-vehicle device 100 includes a wireless unit 101 and a display device 102. Here, the radio unit 101 is equipped with a car navigation device (hereinafter referred to as a car navigation device) and a tuner for terrestrial digital broadcasting as radio devices, and the display unit 102 receives or The transmitted information (car navigation image or TV broadcast image) is displayed.

  The wireless unit 101 has a first casing 103 in which a wireless device (not shown) is accommodated, and the display device 102 has a second casing 104 (* FIG. 1) in which a front panel and the like are accommodated. Not).

  A front panel 105 is provided on the front surface of the second housing 104 (the surface opposite to the first housing 103).

  The front panel 105 is fixed by a second housing 104 and a fixing member 106 on the back surface 105b.

  Further, as shown in FIG. 2, the front panel 105 has a front surface 105 a provided with an opening in addition to various operation keys for operating the above-described car navigation device and wireless devices such as a tuner for terrestrial digital broadcasting. 105c is formed. The front panel 105 is provided with a display 107 composed of a liquid crystal panel or the like.

  As described above, information (car navigation image or television broadcast image) received or transmitted by the wireless unit 101 is displayed on the display 107.

  Here, in the wireless unit 101 and the display device 102, the first housing 103 and the second housing 104 are formed of a metal body in order to make the internal devices less susceptible to external noise. Yes.

  An antenna 201 is disposed on the upper surface of the first housing 103. This antenna 201 is a flat antenna in which conductive paths are two-dimensionally provided on a thin base material, and is arranged so as to maintain a gap 109 of a predetermined distance with respect to the upper surface of the first housing 103. ing. There are various forms of securing the gap 109, which will be described later. In the example of FIG. 1, as an example, the four corners are fixed by the fixing members 108. That is, the antenna 201 is disposed in parallel along the surface of the first housing 103 whose plane is formed of a metal body.

  The antenna 201 includes a radiating element 215 and a feed line 221 connected to the radiating element 215, and is connected to a wireless device housed in the first housing 103 via the feed line 221. Yes.

  Thus, in the wireless unit 101 having the above-described configuration, the antenna 201 is disposed along the surface of the wireless device, that is, the surface of the first housing 103 that accommodates the wireless device. Specifically, the plane of the radiating element 215 constituting the antenna 201 is arranged along the wall surface of the first housing 103.

  Thereby, the wireless unit 101 in which the wireless device and the antenna 201 are integrated can be realized.

  Normally, when the antenna 201 is arranged in parallel along the surface of the first housing 103 formed of the metal body of the wireless unit 101, there is a problem that the transmission / reception sensitivity of the antenna 201 is lowered.

  However, the antenna 201 has a structure that does not cause a decrease in transmission / reception sensitivity even when the antenna 201 is arranged close to a metal body. Details of the antenna structure of the antenna 201 will be described later.

  Below, the attachment structure of the antenna 201 is demonstrated.

  FIG. 3 is a diagram illustrating a connection structure between the antenna 201 and the first housing 103 in the wireless unit 101 illustrated in FIG. 1.

  As shown in FIG. 3, the antenna 201 is fixed to the first housing 103 with a fixing member 108 so that a gap 109 of a predetermined distance h is formed with respect to the arrangement surface 103a of the first housing 103. Has been. That is, a dielectric layer is provided between the antenna 201 and the surface of the first housing 103 formed of a metal body. In the case of the gap 109, the dielectric layer is an air layer.

  Here, the distance h needs to be at least 2 mm in consideration of the sensitivity of the antenna 201. That is, when the distance h is shorter than 2 mm, the antenna 201 may be affected by the first housing 103 and the sensitivity as an antenna may be reduced.

  Therefore, in consideration of the sensitivity as an antenna, the distance h is preferably 2 mm or more. However, in order to realize the integration of the antenna 201 and the wireless device, which is the object of the present invention, the distance h is 2 mm as much as possible. It is preferable to be close to.

  4A and 4B are diagrams illustrating another example of a connection structure between the antenna 201 and the first housing 103. FIG.

  As shown in FIG. 4A, a dielectric layer 110 having a predetermined thickness is formed on the arrangement surface 103a of the first housing 103 instead of the air layer, and the antenna 201 is arranged thereon. You may make it do.

  In this case, the thickness of the dielectric layer 110 is also preferably 2 mm or more, like the distance h described above.

  Also, as shown in FIG. 4B, spacers 111 made of an insulating material (for example, resin) are arranged on the arrangement surface 103a of the first housing 103 at a predetermined interval, and the antenna 201 is formed thereon. May be arranged. Also in this case, it is preferable that the distance between the arrangement surface 103a and the antenna 201 is 2 mm or more, like the distance h described above.

  As described above, in the present invention, it is important that the wireless unit 101 has a structure in which the antenna 201 and the wireless device are integrated.

  Here, integration of the antenna 201 and the wireless device will be described.

  FIG. 5 is a block diagram of the reception system 10 and the transmission system 20 in the in-vehicle device 100. The reception system 10 is mainly assumed to be a system that receives terrestrial digital broadcasting, and the transmission system 20 is mainly assumed to be ITS (Intelligent Transport Systems) that is a communication method such as ETC. In addition, the antenna 201 may be an antenna device for WiMAX communication.

  As shown in FIG. 5, the reception system 10 includes an antenna 201, a reception circuit 11, a demodulation circuit 12, an AV decoder 13, and a car navigation device 14.

  In the reception system 10, a signal (reception signal) received by the reception circuit 11 connected to the antenna 201 via the feeder 221 is transmitted to the demodulation circuit 12 at the subsequent stage.

  The demodulation circuit 12 demodulates the received signal received and transmits it to the AV decoder 13 at the subsequent stage.

  The AV decoder 13 decodes the received demodulated signal and transmits it to the subsequent car navigation device 14.

  The car navigation device 14 displays an image based on the signal decoded by the AV decoder 13.

  On the other hand, the transmission system 20 includes an antenna 201, a transmission circuit 21, a modulation circuit 22, a control unit 23, and a car navigation device 24 as shown in FIG.

  In the transmission system 20, the control unit 23 outputs a control signal to the modulation circuit 22 based on the signal transmitted from the car navigation device 24.

  The modulation circuit 22 modulates the received control signal and transmits it to the subsequent transmission circuit 21.

  The transmission circuit 21 transmits the received control signal from the antenna 201 via the feeder line 221.

  Here, of the reception system 10 and the transmission system 20, the antenna 201, the reception circuit 11, and the transmission circuit 21 are defined as the first integrated circuit 1, and the antenna 201, the reception circuit 11, the transmission circuit 21, the demodulation circuit 12, and the modulation The circuit 22 is defined as the second integrated circuit 2.

  Here, the term “integrated” refers to a state in which it can be attached as one component to a device to be mounted such as a car. Therefore, the integration of the antenna 201 and the wireless device may be the first integrated circuit 1, the second integrated circuit 2, or other components as one component. If it exists, it is good also as a thing including the component.

  Note that if the surroundings of the antenna circuit are covered with a conductor, transmission / reception becomes impossible. Even if the surroundings are not covered, even if there is a conductor plate along the antenna circuit between the antenna circuit and the outside world, transmission / reception is not possible. Characteristics deteriorate. Therefore, when the antenna 201 and the wireless device are integrated, the antenna 201 is disposed on the surface of the conductor plate located on the outermost side of the wireless device or the surface of a dielectric plate such as a resin covering the conductor plate. Is preferred.

(Detailed explanation of antenna circuit)
Here, the details of the antenna 201 will be described.

  Next, the configuration of the antenna circuit unit of the present invention that can be installed along the conductor surface if the distance from the conductor surface is at least 2 mm will be described in detail.

  By the way, since the antenna device is strongly influenced by the surroundings, how to mount the antenna device at the mounting location is an important matter.

  In particular, when the antenna device is mounted on a conductor member made of a metal plate or the like, the influence from the conductor member is inevitable. That is, when the antenna device is mounted on the conductor member, it is necessary to design the antenna device while considering the influence from the conductor member, unlike the case where the antenna device alone is in a vacuum free space.

  Therefore, the antenna device of the present invention is configured in consideration of the influence received from the conductor member when mounted on the conductor member. As a result, as shown in FIG. 6, the antenna 201 as an embodiment of the antenna device of the present invention has a two-dimensional meander-shaped conductive path formed of a folded pattern at least once, more preferably twice or more. Is provided with a flat plate-shaped radiating element 215.

  Furthermore, the inventors of the present application use the short-circuit member 231 (short-circuit portion) that partially short-circuits the conductive path, and determines the position and location where the short-circuit member 231 is disposed, thereby resonating the radiating element 215. It has been found that it is more preferable to increase the VSWR value and decrease the VSWR value. By using the short-circuit member 231, the usable bandwidth can be expanded even when the antenna 201 is mounted on the conductor member.

  The radiating element 215 has a conductive path continuous from one end to the other end, and is a single line. From the point of having a conductive path continuous from one end to the other, it can be said that it is formed in a loop shape. The loop shape can improve the gain of the antenna. And the radiation element 215 is arrange | positioned on the same plane, As a member, a conductor wire, a conductor film, or a printed wiring can be used, for example.

  The radiating element 215 includes a portion having a predetermined length from one end of the radiating element 215 (a portion corresponding to the winding portion 211 below) and a portion having a predetermined length from the other end (corresponding to the winding portion 211 below). Part) become the first and second root parts 225 and 226, respectively. The remaining part of the radiating element 215 excluding the two root parts 225 and 226 is an intermediate part. That is, the intermediate part is a part that relays between the first root part 225 and the second root part 226.

  A part of the intermediate part constitutes a radiating part 212 having a meander shape (a meander-shaped part), and the remaining part of the intermediate part constitutes a first wide part 213 and a second wide part 214, The two root parts 225 and 226 constitute a winding part 211. The first wide portion 213 and the second wide portion 214 share a part of each other.

  To summarize the above configuration, the conductive path starts from the first root portion 225 from one end to the other end of the radiating element 215, and includes the first wide portion 213, the second wide portion 214, and the radiating portion 212. The second root part 226 continues in the order of the second root part 226, and the second root part 226 returns to a position adjacent to the first root part 225.

  In the first root portion 225, the direction of taking out from one end to the other end is leftward in FIG. 7 (the negative direction of the X axis), and in the second root portion 226, taking out from the other end to the one end is performed. The direction is the right direction in FIG. 6 (the positive direction of the X axis). That is, the two directions of taking out are opposite to each other.

  That is, in both of the two root portions 225 and 226, the extending direction thereof is rotated by 180 ° so as to surround the power feeding portion 222.

  For this reason, it is possible to obtain a high radiation gain for each radio wave regardless of whether the radio wave on the low frequency band side or the radio wave on the high frequency band side is transmitted / received.

  Further, the two root portions 225 and 226 are taken out in the direction in which the first root portion 225 extends from the power supply portion 222 described later to the power supply side, that is, in the left direction in FIG. The second root portion 226 is opposite to the direction in which the feeder line 221 extends.

  Specifically, in the winding part 211, in FIG. 6, the extending direction of the first root part 225 is upward (positive direction of the Z axis) from the one end of the radiating element 215, and then leftward. (The negative direction of the X axis, the direction of removal). That is, the first root portion 225 includes a first straight portion 225o1 extending upward, and a first bent portion 225o2 (first rear end straight portion) extending leftward from an end portion of the first straight portion 225o1. have.

  Further, the extending direction of the second root portion 226 is from the other end of the radiating element 215 downward (negative direction of the Z axis) and then rightward (positive direction of the X axis, direction of extraction). It has become. That is, the second root portion 226 includes a second straight portion 226o1 extending downward, and a second bent portion 226o2 (second rear end straight portion) extending rightward from the end portion of the second straight portion 226o1. have.

  As described above, in the winding part 211, the extending direction of each of the two root parts 225 and 226 rotates 90 ° in the opposite directions so as to surround the power feeding part 222. .

  In addition, a part of the intermediate portion of the radiating element 215 has a meander shape including a folded pattern at least once, more preferably two or more times in the radiating portion 212. The folding direction of the meander-shaped folding pattern (positive direction or negative direction of the Z axis) is the direction of taking out the second root part 226 in the winding unit 211 (positive direction of the X axis), that is, It is perpendicular to the direction of the second bent portion 226o2 (rear end straight portion).

  By the way, in the winding part 211, the above-described power feeding part 222 is formed in each of the two root parts 225 and 226. Each of the two root portions 225 and 226 is supplied with power from a power supply line 221 connected to the power supply portion 222.

  The details of the connection configuration between the feeder 221 and the feeder 222 are shown in FIG. In this connection configuration, the outer conductor 122 of the coaxial cable constituting the feeder line 221 supplies power to the first root portion 225, and the inner conductor 123 of the coaxial cable supplies power to the second root portion 226. In addition, a portion (a portion where the external conductor 122 is not exposed) that is adjacent to the portion where the external conductor 122 is exposed and is covered with an insulating outer skin is disposed on the first wide portion.

Regarding power supply from the power supply line 221, specifically, in the power supply unit 222, a signal in a predetermined frequency band is applied to the second root unit 226 via the inner conductor 123 of the coaxial cable, and via the outer conductor 122. In addition, the ground potential is applied to the first root portion 225. The line width (length in the X-axis direction) of the first wide portion 213 that is located below the feed line 221 and overlaps the feed line 221. Is wider than the line width of the portion constituting the winding part 211 and the radiation part 212 of the radiation element 215. As a result, impedance matching between the power supply unit 222 and the power supply line 221 can be realized.

  Similarly to the first wide portion 213, the second wide portion 214 is also wider than the line width of the portions constituting the winding portion 211 and the radiating portion 212.

  Unlike FIG. 6, if the power supply line 221 extends from the power supply unit 222 in the negative direction of the Z axis, the second wide portion 214 serves as the first wide portion 213. . That is, in this case, the line width (the length in the Z-axis direction) of the second wide portion 214 that is positioned below the power supply line 221 and overlaps the power supply line 221 constitutes the winding unit 211 and the radiation unit 212. It can be said that it is wider than the line width of the part.

  As an example of the size of the antenna 201, the length in the left-right direction (X-axis direction) in FIG. 6 is 92 mm, and the length in the vertical direction (Z-axis direction) is 52 mm.

  Further, the short-circuit member 231 is disposed in the meander shape of the radiating portion 212. Here, the role of the short-circuit member 231 will be described below with reference to FIG.

(Role of the short-circuit member 231)
FIG. 7 is a schematic view showing a state in which the short-circuit member 331 is arranged in the radiating element 315 having a meander shape and a plurality of conductive paths are generated in the radiating element 315.

  As shown in FIG. 7, the antenna 301 has a radiating element 315 that is one line, and the radiating element 315 has a meander shape (meander structure). That is, the radiating element 315 is meandered. A feed line is connected to the radiating element 315 at the feed unit 322.

  The short-circuit member 331 short-circuits, for example, two or more different points of the meandering radiation element 315 (a plurality of points). In the example of FIG. 7, the two straight portions extending in the vertical direction located at both ends of the short-circuit member 331 are short-circuited. Accordingly, the radiation element 315 includes a first path (first conductive path) indicated by a solid line corresponding to the first wavelength λ1 and a second path indicated by a broken line corresponding to the second wavelength λ2. A path (second conductive path) is formed.

  In this manner, in the antenna 301, the short circuit member 331 is provided so as to short-circuit a plurality of different points in the meandering radiating element 315, and the number of conductive paths having different lengths is increased. Can be increased. Thereby, the VSWR characteristic of the antenna 301 in the use band can be improved.

  Here, as described above, when the antenna device is mounted on a conductor member, it is affected by the conductor member, so that the use band (for example, 470 MHz to 770 MHz for a terrestrial digital broadcasting antenna for Japan, In the case of a digital broadcasting antenna, the VSWR characteristic at 470 MHz to 860 MHz and in the case of a European terrestrial digital broadcasting antenna 470 to 890 MHz) may deteriorate (VSWR value increases).

  In such a case, as shown in the antenna 301 of FIG. 7, in the meandering radiating element 315, by providing a short-circuit member 331 so as to short-circuit a plurality of different points, a VSWR characteristic in the use band is obtained. Deterioration (increase in VSWR value) can be suppressed. That is, in consideration of the influence from the conductor member, the position where the short-circuit member 331 short-circuits in the radiating element 315 is determined in the state where the dummy conductive member is disposed in the vicinity of the radiating element 315, and the short-circuit member 331 is disposed. As a result, the number of conductive paths having different lengths increases and the resonance frequency of the antenna 301 increases. As a result, even when the antenna 301 is mounted on a conductor member, it is possible to suppress deterioration of the VSWR characteristics (increase in the VSWR value) in the use band due to the influence of the conductor member.

  In the antenna 201 shown in FIG. 6, the short-circuit member 231 is arranged in the meandering radiation portion 212 as the short-circuit member 331 as described above. Determination of the position and location which arrange | positions this short circuit member 231 is performed as follows, for example.

  The arrangement of the short-circuit member 231 is smaller than that in the case where the short-circuit member 231 is not arranged in a state where the radiating element 215 is arranged on the metal plate via the dielectric, and at each frequency in the use band. Decide as follows. More preferably, the VSWR value at each frequency in the use band is determined to be 3.5 or less in a state where the radiating element 215 is disposed on the metal plate via the dielectric.

  More specifically, after the short-circuit member 231 is temporarily placed on the radiating element 215 disposed on the dummy metal plate via the dielectric, the short-circuit member 231 is moved while monitoring the VSWR value in the use band. . And when the position where VSWR value becomes smaller than the case where the short circuit member is not arrange | positioned in each frequency in a use band is found, the short circuit member 231 is fixed to the position. On the other hand, when the position where the VSWR value becomes smaller than the case where the short-circuit member is not arranged at each frequency in the use band cannot be found, the above-described trial is performed while replacing the short-circuit member 231 to be used with one having a different shape or size. repeat.

  The short-circuit member 231 short-circuits predetermined positions of the radiating element 215, and for example, a conductive material such as a metal material can be used. For example, the short-circuit member 231 directly contacts the radiating element 215 and short-circuits the radiating element 215.

  Here, the experimental results of examining the relationship between the presence / absence of the short-circuit member 231 and the VSWR characteristics will be described below.

(Effects due to the presence or absence of short-circuit members)
In this experiment, as shown in FIG. 8, an antenna device 401 was mounted on a metal plate 403 as a conductor member of 350 mm × 250 mm via a dielectric layer 402. The dielectric layer 402 will be described later. Note that if the size of the antenna device 401 is about 100 mm × 50 mm, the antenna device 401 is mounted on a conductor member such as an automobile bonnet, which has substantially the same characteristics as when the antenna device 401 is mounted on a conductor member of 350 mm × 250 mm. It can also be obtained when installed.

  As the antenna device 401, the antenna 201 shown in FIG. 7 and the antenna 501 shown in FIG. 9 were used, and the VSWR characteristics were measured for each of them. Note that the antenna 501 in FIG. 9 has the same configuration as the antenna 201 in FIG. 6 except that the short-circuit member 231 provided in the antenna 201 in FIG. 6 is not provided.

FIG. 10 is a graph showing the measurement results of the VSWR characteristics of the antenna 201 and the antenna 501. In FIG. 10, the graph “with short circuit member” is the measurement result of the antenna 201, and the graph of “without short circuit member” is the measurement result of the antenna 501. At the time of this measurement, the thickness d of the dielectric layer 402 was 5 mm, and the relative dielectric constant ε _r was 1.

  From the experimental results shown in FIG. 10, the short circuit member 231 is arranged in the antenna 201 to cause a short circuit, so that the VSWR is 3.5 or less in a band of 800 MHz or less with respect to the terrestrial digital television band (470 MHz to 770 MHz). It can be seen that

  However, also in the antenna 501, the VSWR is suppressed to 3.5 or less in the frequency band of about 650 MHz to 750 MHz, so that satisfactory transmission / reception can be performed in this frequency band. This is considered to be an effect of the antenna 501 including the radiating element 215 having a meander-shaped conductive path.

  In the case of the antenna 501, a favorable frequency band is about 650 MHz to 750 MHz, but this is merely an example. That is, depending on the meander shape design, the value and range of the frequency at which the VSWR is 3.5 or less can be changed variously. Therefore, depending on the frequency band used, the short-circuit member may not be provided.

  In addition, although this Embodiment demonstrated by short-circuiting several adjacent points on the same plane, you may short-circuit several points which are not adjacent. For example, a short-circuit member having a non-linear shape may be short-circuited, or a two-layer structure may be provided on a surface different from the antenna 201 to short-circuit two or more points separated by interlayer conduction.

(Effects of dielectric thickness)
As shown in FIG. 8, the inventors have provided a dielectric layer 402 between the antenna device 401 and a metal plate 403 as a conductor member, thereby providing a gap between the antenna device 401 and the conductor member (metal plate 403). It has been found that an antenna device having VSWR characteristics that can withstand practical use can be realized even if the distance is reduced to about several millimeters. At this time, the relative dielectric constant ε _r of the dielectric layer 402 is preferably set to 1 or more and 10 or less. This is because if the relative dielectric constant ε _r is greater than 10, the reduction in radiation efficiency cannot be ignored.

  FIG. 11 shows the measurement results of the VSWR characteristics of the antenna device 401 at each thickness d when the thickness d of the dielectric layer 402 is changed. Here, the antenna 201 in FIG. 6 is used as the antenna device 401.

  Further, as the thickness d, four conditions of d = infinity (∞), d = 5 mm, d = 2 mm, d = 0 mm were prepared. Note that d = infinity is a condition that means that the distance between the antenna 201 and the metal plate 403 is infinite, that is, the metal plate 403 does not exist. D = 0 mm is a condition that means a situation in which the antenna 201 is mounted so as to contact the metal plate 403 through an insulating member such as an insulating film that is as thin as possible. That is, d = 0 mm indicates a distance in which the conductor portion of the antenna 201 and the metal plate 403 are kept in an insulating state without being in direct contact and the antenna 201 and the metal plate 403 are as close as possible.

  As shown in FIG. 11, it can be seen that VSWR can be suppressed to 3.5 or less in the band of 470 MHz to 770 MHz under the two conditions of d = infinity and d = 5 mm. Further, even when d = 2 mm, it can be seen that the VSWR can be suppressed to 3.5 or less in the band of 470 MHz to 770 MHz except for the band near 670 MHz. From this, the following can be said.

  If d = infinity, that is, if the antenna 201 is not mounted on the metal plate 403, the antenna 201 is not affected by the metal plate 402. In other words, if the antenna 201 approaches the metal plate 403 gradually from infinity to the metal plate 403, the closer to the metal plate 403, the stronger the influence from the metal plate 403 should be.

  Therefore, what can be said from the result of FIG. 11 is that if the thickness d of the dielectric layer 402 between the antenna 201 and the metal plate 403, that is, the distance between the antenna 201 and the metal plate 403 is 5 mm or more, It can be said that VSWR can be suppressed to 3.5 or less in the band of 470 MHz to 770 MHz. Further, if the distance between the antenna 201 and the metal plate 403 is 2 mm or more, the VSWR can be suppressed to 3.5 or less in the band of 470 MHz to 770 MHz except for some exceptional bands. I can say that.

Here, FIG. 11 shows a case where an antenna base material having a relative dielectric constant ε _r of about 2 to 3 and a thickness of 1 mm or less is used, and the distance other than the base material, that is, the thickness d of the dielectric layer 402 is _expressed as the relative dielectric constant. The characteristic is shown when the material is provided with a material (such as polystyrene foam) having a ratio ε _r = about 1.

Therefore, in the characteristics shown in FIG. 11, when the thickness d = 2 mm, the VSWR deteriorates in the vicinity of 670 MH, but in the present invention, the VSWR in the 670 MHz band does not necessarily deteriorate. This is characteristic shown in FIG. 11, the short circuit member or meander, the relative dielectric constant epsilon _r and thickness of the antenna base, be adjusted by optimizing the relative permittivity epsilon _r and the like of the dielectric layer 402 Because it is possible.

FIG. 12 is a graph showing a radiation pattern in the 550 MHz band of the antenna 201 shown in FIG. 8A shows a radiation pattern on the xy plane of the xyz coordinate system shown in FIG. 8, FIG. 8B shows a radiation pattern on the yz plane, and FIG. 8C shows a radiation pattern on the zx plane. At this time, the thickness d of the dielectric layer 402 was 5 mm, and the relative dielectric constant ε _r was 1. In addition, Eθ shown in FIG. 12 represents the radiation power of the antenna with respect to the vertical polarization V, Eφ represents the radiation power of the antenna with respect to the horizontal polarization H, and Etotal represents the total radiation power of the antenna.

  As can be seen from FIG. 12, the radiation omnidirectionality is realized in any of the radiation pattern on the xy plane, the radiation pattern on the yz plane, and the radiation pattern on the zx plane.

(Modification)
FIG. 13 shows an antenna 201 a which is a modification of the antenna 201. In the following, detailed description of parts different from the antenna 201 will be given, and description of the same parts will be omitted.

  As for the size of the antenna 201a, the length in the left-right direction (X-axis direction) in FIG. 13 is 83 mm, and the length in the vertical direction (Z-axis direction) is 56 mm.

  In the winding part 211a, a power feeding part 222a is formed on each of the two root parts 225a and 226a of the radiating element 215a. Each of the two root portions 225a and 226a is supplied with power from a power supply line 221a connected to the power supply portion 222a.

  The first base portion 225a has a first straight portion 225a1 and a first bent portion 225a2 (first rear end straight portion). The first straight portion 225a1 and the first bent portion 225a2 correspond to the first straight portion 225o1 and the first bent portion 225o2 of the first root portion 225 shown in FIG. Similarly, the second root portion 226a has a second straight portion 226a1 and a second bent portion 226a2 (second rear end straight portion). The second straight portion 226a1 and the second bent portion 226a2 correspond to the second straight portion 226o1 and the second bent portion 226o2 of the second root portion 226 shown in FIG.

  The feeding line 221a extends from the feeding unit 222a in a negative direction of the Z axis in FIG. 13 unlike the feeding line 221 of the first embodiment.

  For this reason, the direction in which the two root portions 225a and 226a are taken out is orthogonal to the direction in which the power supply line 221 extends in FIG. 7, and is parallel to the direction in which the power supply line 221a extends. .

  The first wide portion 213a is formed below the power supply line 221a, and the line width (the length in the X-axis direction) of the portion overlapping the power supply line 221a constitutes the winding portion 211a and the radiation portion 212a. It is wider than the line width of the part.

  Unlike FIG. 13, the power supply line 221 a may extend from the power supply unit 222 a in the negative direction of the X axis.

  Further, the short-circuit member 231a and the short-circuit member 232a are disposed in the meander shape of the radiation portion 212a. The roles of the short-circuit member 231a and the short-circuit member 232a are the same as those of the short-circuit member 231 described above.

  Next, the inventors conducted experiments on how much the VSWR characteristics are improved by the presence or absence of the short-circuit members 231a and 232a. The experimental results will be described below.

(Effects due to the presence or absence of short-circuit members)
As in the case of the antenna 201, the inventors mounted an antenna device 401 on a 350 mm × 250 mm metal plate 403 via a dielectric layer 402 as shown in FIG.

  As the antenna device 401, the antenna 201a shown in FIG. 13, the antenna 502 shown in FIG. 14, and the antenna 503 shown in FIG. 15 were used, and the VSWR characteristics were measured for each of them. The antenna 502 in FIG. 14 has the same configuration as the antenna 201a in FIG. 13 except that the short-circuit member 232a in FIG. 13 is not disposed in the meander shape portion of the radiating portion 212a. Further, the antenna 503 in FIG. 15 has the same configuration as the antenna 201a in FIG. 13 except that the short-circuit members 231a and 232a in FIG. 13 are not arranged in the meander shape portion of the radiating portion 212a.

FIG. 16 shows measurement results of the VSWR characteristics of the antenna 201a, the antenna 502, and the antenna 503. In FIG. 16, the graph “with short circuit member” is the measurement result of the antenna 201 a, the graph “without short circuit member” is the measurement result of the antenna 503, and the graph “without second short circuit member” is the antenna 502. It is a measurement result. At the time of this measurement, the thickness d of the dielectric layer 402 was 5 mm, and the relative dielectric constant ε _r was 1.

  As shown in FIG. 16, first, from the graph of “no second short-circuit member”, the short-circuit member 231a is arranged to cause a short-circuit, thereby generating a low frequency in the terrestrial digital television band (470 MHz to 770 MHz). It can be seen that VSWR can be suppressed to 3.5 or less in the band.

  Furthermore, from the graph of “with short circuit member”, by arranging the short circuit member 232a and causing a short circuit, the VSWR is suppressed to 3.5 or less even in the high frequency band of the terrestrial digital television band (470 MHz to 770 MHz). I understand that

  However, from the graph of “no short-circuit member”, as described above, in the antenna 503, the VSWR is suppressed to 3.5 or less in the frequency band of about 550 MHz to 620 MHz and the frequency band of about 680 MHz to 770 MHz. In this frequency band, good transmission / reception can be performed. This is considered to be an effect of the antenna 503 including the radiating element 215a having a meander-shaped conductive path. Therefore, the number of short-circuit members installed, including zero, can be changed depending on the frequency band used.

(Effects of dielectric thickness)
FIG. 17 shows the measurement results of the VSWR characteristics of the antenna device 401 at each thickness d when the thickness d of the dielectric layer 402 is changed. Here, the antenna 201 a in FIG. 13 is used as the antenna device 401.

  Further, as the thickness d, four conditions of d = infinity (∞), d = 5 mm, d = 2 mm, d = 0 mm were prepared.

  As shown in FIG. 17, it can be seen that VSWR can be suppressed to 3.1 or less in the 420 MHz to 920 MHz band under the two conditions of d = infinity and d = 5 mm.

  Further, it can be seen that VSWR can be suppressed to 3.5 or less in the band of 420 MHz to 870 MHz under the three conditions of d = infinity, d = 5 mm, and d = 2 mm.

  From this, it can be said that if the distance between the antenna 201 and the metal plate 403 is 2 mm or more, the VSWR can be suppressed to 3.5 or less in the band of 420 MHz to 870 MHz.

  Here, FIG. 17 shows a case where an antenna substrate having a relative dielectric constant εr of about 2 to 3 mm is used, and a distance other than the base material, that is, the thickness d of the dielectric layer 402 is expressed as a relative dielectric constant εr. = Indicates characteristics when provided with about 1 material (such as polystyrene foam).

  Even in the case of d = 0 mm, for example, in a frequency band near 450 MHz, a frequency band such as about 520 MHz to 690 MHz and about 750 MHz to 830 MHz, VSWR can be suppressed to 3.5 or less, and good transmission / reception can be performed. . Therefore, when the use frequency band may be limited to a specific frequency band, the antenna 201 including the meander-shaped radiating element 215 of the present invention is insulated from the conductor surface (the surface of the first housing 103). It is possible to install it as close as possible while maintaining the same state.

FIG. 18 is a graph showing a radiation pattern in the 550 MHz band of the antenna 201a shown in FIG. (A) is a radiation pattern on the xy plane, (b) is a radiation pattern on the yz plane, and (c) is a radiation pattern on the zx plane. At this time, the thickness d of the dielectric layer 402 was 5 mm, and the relative dielectric constant ε _r was 1.

  As can be seen from FIG. 18, the radiation omnidirectionality is realized in any of the radiation pattern on the xy plane, the radiation pattern on the yz plane, and the radiation pattern on the zx plane.

(Modification)
FIG. 19 illustrates an antenna 504 that is a modification of the antenna 201 illustrated in FIG. 7. In the following, detailed description of parts different from the antenna 201 will be given, and description of the same parts will be omitted.

  In the antenna 504, the lengths of the first wide portion 213b and the winding portion 211b in the positive Z-axis direction are longer than the first wide portion 213 and the winding portion 211 of the antenna 201. Therefore, the upper ends on the Z-axis positive direction side of the first wide portion 213b and the winding portion 211b protrude from the position of the upper end portion on the Z-axis positive direction side of the radiating element 215 to the Z-axis positive direction side.

  Further, although the short-circuit member 231 of the antenna 201 is provided as an independent member, in the antenna 504, the conductive material is made of the same material as that of the conductive path forming the radiating element 215b at the lower end portion on the Z-axis negative direction side. A short-circuit portion 231c integrated with the path is formed. Further, two conductive paths that are folded back along the Z axis and run side by side are integrated into one, and the width in the X-axis direction is approximately three times the width of one conductive path. The short-circuit part 231d thus formed is formed. Needless to say, the number of parallel conductive paths in the case of integration into one may be appropriately adjusted so as to obtain good VSWR characteristics. Similarly, the length of the short-circuit portion 231c in the X-axis direction can be adjusted as appropriate.

  In this way, instead of using the short-circuit member as an independent member, it is possible to form the conductive path and the short-circuit member at the same time by forming the short-circuit member integrally with the conductive path using the same material as the conductive path. As a result, the manufacturing process is simplified.

(Antenna circuit mounting modification 1)
20A and 20B are diagrams illustrating an example of mounting the antenna 201 in the wireless unit 101. FIG.

  As shown in FIG. 3, the antenna 201 may be attached by providing a gap 109 on the first housing 103 formed of a metal body. However, the flat plate-shaped radiating element 215 constituting the antenna 201 is made of an insulating material. It may be embedded in the wall surface formed from or fixed along the wall surface. For example, as shown in FIGS. 20A and 20B, the antenna 201 covers the first housing 103, and the wall surface 112a of the dome-shaped insulating cover 112 (Mr. Yamada; 112a in FIG. 20 did not appear) You may attach to.

  FIG. 20A shows an example in which the antenna 201 is attached to a surface facing the arrangement surface 103 a of the first housing 103 on the outside of the insulating cover 112.

  FIG. 20B shows an example in which the antenna 201 is attached to a surface inside the insulating cover 112 that faces the arrangement surface 103 a of the first housing 103.

  As described above, an insulating cover 112 as an insulating material surface is formed outside the conductive layer on the surface of the first housing 103 that accommodates the wireless device in the wireless unit 101, and the antenna 201 is connected to the insulating cover 112. The distance between the antenna 201 and the first housing 103 can be obtained with certainty. Therefore, the influence of the first housing 103 on the antenna 201 can be reduced, so that necessary antenna performance can be maintained.

(Antenna circuit mounting modification 2)
In addition, as shown in FIG. 21, the first housing 103 may include a curved surface 103c with a corner having a curvature, and the antenna 201 may be disposed along the curved surface 103c. Also in this case, the curved surface 103c and the antenna 201 are provided so as to be separated from each other by 2 mm or more.

  The curvature radius of the curved surface 103c is preferably 5 mm or more. That is, in order to maintain the antenna characteristics, it is preferable that the radius of curvature of the portion B corresponding to the curved surface 103c in the antenna 201 is also 5 mm or more.

  Further, two antennas 201 may be arranged as shown in FIG. 21 using the curved surface 103c formed at the corner of the first housing 103. It is sufficient that at least two radiating elements 215 constituting the antenna 201 are arranged.

  In this case, the two antennas 201 can be used for diversity reception. That is, since the reception signal of the antenna 201 with good reception conditions can be used preferentially, the reception sensitivity in the wireless unit 101 can be improved.

  Note that the number of antennas 201 is not limited to two, and a plurality of antennas 201 may be arranged. However, it is desirable that the antennas 201 be arranged at a certain distance from each other in consideration of reception sensitivity.

  In the example shown in FIG. 21, the antenna 201 is attached to the first housing 103 so that the gap 109 is formed by the fixing member 108, that is, the antenna 201 and the first housing, as in the case shown in FIG. The arrangement surface 103a is fixed along the curved surface 103c and the side surface 103b so as to maintain the distance from the device 103. In place of the gap 109, the dielectric layer 110 may be provided between the antenna 201 and the first housing 103 and fixed as in the case shown in FIG. .

  Further, the mounting position of the antenna 201 may be on the arrangement surface 103a which is a flat surface instead of the curved surface 103c of the first housing 103 as described above. In this case, as described above, it is preferable that the antennas 201 are arranged at some distance from each other in consideration of reception sensitivity.

(The antenna circuit and the transmission / reception circuit are formed on the same plane)
The antenna 201 may be formed on the same plane as one or both of the reception circuit 11 and the transmission circuit 21 in the wireless unit 101. Specifically, as illustrated in FIG. 22, the antenna 201 and one or both of the reception circuit 11 and the transmission circuit 21 in the wireless unit 101 are formed on a single insulating substrate 200 (support member). The Here, the antenna 201 is connected to one or both of the reception circuit 11 and the transmission circuit 21 via a power supply line 221 connected to the power supply unit 222.

  Further, when both the receiving circuit 11 and the transmitting circuit 21 are formed on the same plane as the antenna 201, for example, the first integrated circuit 1 shown in FIG. 5 and the antenna 201 are formed on the same plane. Will do.

  Further, as shown in FIG. 5, the second integrated circuit 2 obtained by adding the demodulation circuit 12 and the modulation circuit 22 to the first integrated circuit 1 and the antenna 201 are formed on the same plane. It may be.

  According to the above configuration, there is an effect that the wireless device can be further reduced in size or thickness, or an effect that there is no need to consider the impedance of the transmission path between the antenna and the transmission / reception circuit because the transmission / reception circuit can be adjacent to the antenna device. .

(Operational effect by using the antenna device of the present invention)
The flat antenna 201 of the present invention is arranged along the surface (wall surface) of the wireless device so that at least the plane of the radiating element 215 constituting the antenna is located outside the first housing 103 made of a metal body. By arranging, the antenna 201 and the wireless device are integrated. For this reason, there is an advantage that the volume of the wireless device is not increased and a troublesome wiring work is not required.

  Further, since the antenna 201 of the present invention is non-directional and has high sensitivity, even if the antenna 201 is arranged along the metal surface, it is highly sensitive (it should be at least 2 mm away from the metal surface). Moreover, there is no decrease in sensitivity even if it is bent. However, it is necessary to bend the curvature radius to be 5 mm or more.

  Thus, the antenna 201 of the present invention is planar and can be bent. Therefore, even if the surface shape of the wireless device to be attached is not flat, it can be attached along the surface shape of the wireless device.

  Therefore, when the antenna 201 of the present invention is used, the wireless device can be freely arranged regardless of the shape, and the degree of freedom in designing the wireless device is increased.

  Further, since the antenna 201 can be provided in the vicinity of the first housing 103, the length of the feeder line 221 for connecting the antenna 201 and the wireless device can be shortened. Conventionally, since the length of the feeder line 221 is increased, the thickness of the feeder line 221 is increased by an amount corresponding to an increase in loss. However, as described above, if the length of the feeder line 221 can be reduced. The thickness of the power supply line 221 can also be reduced.

  The in-vehicle device 100 of the present invention is formed by performing predetermined patterning on a thin substrate disposed 2 mm or more away from a metal part of the in-vehicle device 100 (such as the first housing 103 of the wireless unit 101). The directional antenna 201 and the metal part are installed inside a dielectric housing (insulating cover 112) so as to be separated by 2 mm or more. At this time, in order to connect the antenna 201 to the first housing 103, a connection mechanism (fixing member 108) is used. Further, the antenna 201 on the thin substrate and the tuner in the in-vehicle device are electrically connected.

  In addition, as the antenna 201 of the present invention, any one of a radio antenna, a digital television antenna, a GPS antenna, an ITS antenna, a WiMAX antenna, and an information wireless antenna is used as the first housing 103 of the wireless unit 101. Two or more may be connected to the first housing 103 of the wireless unit 101 and integrated.

(Specific example of mounting location of wireless unit 101)
The above-described wireless unit 101 can be mounted on various devices such as a car navigation system, a personal computer, and a dedicated portable TV in addition to a mobile phone.

  When the wireless unit 101 is used as, for example, a navigation device or a tuner for terrestrial digital broadcasting, as shown in FIG. 23, it may be built in a dashboard 602 of a car 601. In this case, the wireless unit 101 is mounted as an in-vehicle device 100 such as a navigation system arranged on the instrument panel of the car 601.

  In such an in-vehicle device 100, since the antenna 201 is formed integrally with the wireless unit 101, the wiring between the antenna device and the in-vehicle device separately provided outside the vehicle or in the vehicle as in the past is provided. Since it becomes unnecessary, it looks better.

  The in-vehicle device 100 is mounted on the car 601. In such a state, the antenna 201 of the wireless unit 101 in the in-vehicle device 100 exists in the car 601. That is, the antenna 201 is covered with the conductor member that constitutes the car 601. Normally, when the antenna 201 is covered with the conductor member in this way, transmission / reception of radio waves is hindered. Here, in the car 601, there are a dashboard 602 made of resin as a member covering the antenna 201, and a windshield existing on the front surface of the dashboard 602, and this windshield is the outermost surface of the car 601. Therefore, the conductor member (metal member) constituting the car 601 is arranged at a position where the radio wave received by the antenna 201 is not obstructed.

  Therefore, if the in-vehicle device 100 is mounted so as to be built in the dashboard 602 of the car 601, it can function sufficiently as a wireless device. In other words, the dashboard 602 is opposite to the wall surface of the wireless device 101 of the radiating element 215 constituting the antenna 201 held along the first housing 103 (wall surface formed of a conductive material) of the in-vehicle device 100. A non-shielding space is formed on the side.

  As described above, even when the radiating element 215 of the antenna 201 is covered with the conductor member, if the conductor member is arranged at a position that does not interfere with the radio wave received by the antenna circuit, the radio wave wraps around. Therefore, since it can be received by the antenna 201, it can function sufficiently as a wireless device.

  Further, the antenna 201 may be provided not only in the first housing 103 of the wireless unit 101 but also in the second housing 104 that is the housing of the display device 102 as shown in FIG. 1 (see FIG. 1). Antenna 201 shown in phantom lines.

  Further, if the antenna 201 is entirely formed of transparent electrodes, for example, as shown in FIG. 2, it can be provided on the back side of the liquid crystal panel of the display 107 (antenna 201 shown by the phantom line in FIG. 2).

  The antenna device of the present invention can also be configured as follows.

  The wireless device of the present invention is a wireless device including a planar antenna circuit in which a conductive path is two-dimensionally provided and a wireless device connected to the antenna circuit. The antenna circuit is arranged so as to be along a wall surface constituting the apparatus.

  Here, the wall surface configuring the wireless device includes, for example, a wall surface of a housing that accommodates the wireless device and a wall surface of a cover that covers the wireless device.

  Therefore, according to said structure, since the said antenna circuit is distribute | arranged so that the plane of an antenna circuit may follow the wall surface which comprises a radio | wireless apparatus, a radio | wireless apparatus and an antenna circuit can be arrange | positioned closely. . As a result, the wireless device and the antenna circuit are integrated in the wireless device. Here, if the antenna circuit has flexibility, even if the wall surface is curved, it is easy to follow the curved surface.

  As described above, if the wireless device and the antenna circuit are integrated, it is possible to eliminate poor visual appearance caused by routing the wiring connecting the antenna circuit and the wireless device, and the wireless device. Miniaturization can be achieved.

  Furthermore, since the wiring connecting the antenna circuit and the wireless device can be shortened, the loss due to the wiring is reduced, and as a result, the wiring used can be thinned.

  If the wiring can be made thin in this way, the device can be further downsized.

  Note that the wireless device of the present invention may be used for transmission / reception, transmission-only, or reception-only.

  Preferably, the antenna circuit includes a radiating element that is continuous from one end to the other end and has a meander-shaped conductive path formed of at least two folded patterns, and a support member that supports the radiating element.

  According to the above configuration, an antenna circuit that is hardly affected by a conductive member such as a metal can be obtained, and therefore the antenna circuit can be disposed close to a conductive member such as a metal.

  Accordingly, the antenna circuit can be arranged in the vicinity of the metal casing housing the wireless device, and the integration of the wireless device and the antenna circuit is facilitated, so that the wireless device can be easily downsized. .

  The radiating element may have power feeding portions formed at both ends of the conductive path.

  According to the above configuration, in a radiating element having a conductive path continuous from one end to the other end, a high radiation gain is realized by forming a feeding portion on both ends of the radiating element as in a loop antenna device having a loop shape. be able to.

  In addition, since the radiating elements constituting the antenna circuit can be formed in a loop shape, the conductive path can be provided two-dimensionally. That is, the antenna circuit can have a planar antenna structure.

  Since such a planar antenna can be arranged in parallel to the metal surface of the metal housing that accommodates the wireless device, an increase in the thickness of the device by the antenna circuit arranged along the wireless device is as much as possible. Can be small.

  In addition, since the conductive path of the antenna circuit has a meander shape as described above, the antenna circuit is hardly affected by the metal casing that accommodates the wireless device, and the deterioration of the antenna performance can be suppressed.

  The radiating element includes (1) a first root portion that is one end side of the conductive path, a second root portion that is the other end side of the conductive path, and the first root portion and the second root portion. (2) The power feeding part is formed in the first root part and the second root part, and (3) the first root part and the second part are provided. Is formed in a first region which is a part of the region where the conductive path is formed, and (4) the first portion The direction in which the first rear end straight portion connecting the first root portion and the intermediate portion in the region extends from the first root portion to the intermediate portion is the second root portion. And the second rear end straight portion connecting the intermediate portion is opposite to the direction extending from the second root portion to the intermediate portion, and (5) the first It is preferable that at least one of the main part and the second root part is formed with a wide part in which the width at the position overlapping the power supply line connected to the power supply part is wider than the other position. .

  As a result, impedance matching between the radiating element and the feeder line in the power feeding unit is realized, and by doing so, the VSWR value of the radiating element can be reduced, that is, the VSWR characteristic can be improved.

  For this reason, since the VSWR characteristic can be improved while realizing a high radiation gain of the radiating element, the usable frequency band of the radiating element can be expanded.

  It is preferable that at least one short-circuit portion for forming a short-circuit path in the meander-shaped conductive path is formed in the conductive path.

  According to the above configuration, since the number of conductive paths having different lengths can be increased by forming at least one short-circuit portion that short-circuits the conductive paths, the resonance point of the antenna can be increased. The usable frequency band of the device can be further expanded.

  In this case, when arranging one or a plurality of short-circuit portions for generating a short-circuit portion on the meander-shaped conductive path, the resonance point of the antenna is increased or the resonance point of the antenna is increased. The position and location where the short-circuit portion is arranged can be determined so as to reduce the VSWR value in the use band.

  When the wall surface constituting the wireless device on which the antenna circuit is arranged is a conductor surface made of a conductive layer, the antenna circuit is preferably arranged apart from the conductor surface.

  According to the above configuration, since the antenna circuit is separated from the conductor surface, the antenna circuit is hardly affected by the conductor surface, and the VSWR value within the use band of the antenna circuit can be reduced.

  The distance of the antenna circuit from the conductor surface is preferably at least 2 mm.

  According to the above configuration, a usable frequency band in which the VSWR value is suppressed to 3.5 or less can be developed even when the antenna circuit is mounted near the conductor.

  A conductor member may be disposed at a position on the opposite side of the conductor surface through the antenna circuit so as not to inhibit radio waves received by the antenna circuit.

  According to the above configuration, even if a conductor member that covers the antenna circuit is provided on the conductor surface on which the antenna circuit is disposed, the conductor member is disposed at a position that does not hinder radio waves received by the antenna circuit. Therefore, it can function sufficiently as a wireless device.

  For example, even if the antenna circuit is arranged on the conductor surface with a space, if the conductor member is disposed on the side opposite to the conductor surface so as to cover the antenna circuit, the antenna circuit is surrounded by the conductor member. As a result, the conductor member needs to be arranged at a position that does not inhibit the radio waves received by the antenna circuit, as described above. That is, it is necessary to separate the antenna circuit and the conductor member so that the radio wave can circulate.

  It is preferable that an insulating material is formed to cover the wireless device, and the antenna circuit is arranged along the front surface or the back surface of the insulating material.

  The wall surface configuring the wireless device may include a curved surface with a curvature, and the antenna circuit may be arranged along the curved surface.

  According to the above configuration, the antenna circuit is not only on the plane of the housing formed of various positions, for example, a metal or a dielectric material, along the wall surface configuring the wireless device, but also on the upper surface and the side surface. When the edge portion which is a boundary is rounded, it is possible to arrange the edge portion from the upper surface to the side surface, so that the degree of freedom of arrangement of the antenna circuit is increased. As a result, the degree of freedom in designing the entire wireless device is increased.

  The curvature radius of the curved surface is preferably 5 mm or more.

  According to said structure, when an antenna circuit is distribute | arranged along the curved surface of a radio | wireless apparatus, it becomes possible to maintain an antenna characteristic. That is, when the curvature radius is smaller than 5 mm, it is difficult to maintain the antenna characteristics.

  Preferably, the wireless device includes a transmission / reception circuit connected to the antenna circuit, and the antenna circuit and the transmission / reception circuit are arranged on the same plane.

  According to said structure, size reduction of a radio | wireless apparatus can be achieved further.

  The wireless device may include at least two antenna circuits.

  According to the above configuration, since at least two antenna circuits are arranged, a signal can be received by selecting an antenna circuit with good reception sensitivity. Therefore, the reception sensitivity of the wireless device can be improved.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The present invention can be applied to an antenna device for receiving broadcast waves. Specifically, for example, it can be used for wireless devices that require an antenna device installed in a portable device with a display function or a personal computer that can transmit and receive in both the VHF broadcast band and the UHF digital terrestrial broadcast band. it can.

DESCRIPTION OF SYMBOLS 1 1st integrated circuit 2 2nd integrated circuit 10 Reception system 11 Reception circuit 12 Demodulation circuit 13 AV decoder 14 Car navigation apparatus 20 Transmission system 21 Transmission circuit 22 Modulation circuit 23 Control part 24 Car navigation apparatus 100 Car-mounted apparatus (radio | wireless apparatus) )
DESCRIPTION OF SYMBOLS 101 Wireless unit 102 Display apparatus 103 1st housing | casing 103a Arrangement surface 103b Side surface 103c Curved surface 104 2nd housing | casing 105 Front panel 105a Front surface 105b Back surface 105c Opening part 106 Fixing member 107 Display 108 Fixing member (supporting member)
109 Gap 110 Dielectric layer (support member)
111 Spacer (support member)
112 Insulating cover 112a Wall surface 200 Insulating substrate (supporting member)
201 Antenna 201a Antenna 211 Winding part 211a Winding part 211b Winding part 212 Radiating part 212a Radiating part 213 First wide part 213a First wide part 213b First wide part 214 Second wide part 215 Radiating element 215a Radiation element 215b Radiation element 221 Feed line 221a Feed line 222 Feed part 222a Feed part 225 Root part 225 First root part 225a First root part 225a1 First straight part 225a2 First bent part 225o1 First straight part 225o2 first bent portion 226 second root portion 226a second root portion 226a1 second straight portion 226a2 second bent portion 226o1 second straight portion 226o2 second bent portion 231 short-circuit member 231a short-circuit member 231c short-circuit Part 231d Short-circuit part 232a Short-circuit member 301 Antenna 315 Radiating element 32 Feeding portion 331 short-circuit member 401 antenna device 401 dielectric 402 metal plate 402 dielectric layer 403 metal plate 501 Antenna 502 Antenna 503 Antenna 504 Antenna 601 car (moving body)
602 Dashboard

Claims (14)

In a wireless device composed of a planar radiating element in which a conductive path is two-dimensionally arranged and a wireless device connected to the radiating element via a feeder line,
A radio apparatus characterized in that a plane of the radiation element is arranged along a wall surface of the radio device. The radiating element is
A first root portion of a predetermined length from one end of the conductive path;
A second root portion of a predetermined length from the other end of the conductive path;
An intermediate portion that relays the first root portion and the second root portion;
In each tip region of the first and second root parts, a power feeding part connected to a power feeding line is formed,
The wireless device according to claim 1, wherein a meander-shaped conductive path having a folded pattern is formed in the intermediate portion. The radiating element includes
The radio apparatus according to claim 2, wherein a short-circuit portion that short-circuits the meander-shaped conductive path is provided. The radiating element includes
The first and second root portions provided on one end side and the other end side of the conductive path are formed with a winding portion surrounding the power feeding portion,
4. The radio apparatus according to claim 2, wherein a wide portion having a wide width of the conductive path is formed in at least one of the first and second root portions.   The wireless device according to claim 2, wherein the radiating element is a single line that is continuous from one end to the other end.   The wireless device according to claim 1, wherein the radiating element is disposed along a wall surface formed of a conductive material.   The wireless device according to claim 1, wherein the radiating element is held at least 2 mm away from a wall surface made of a conductive material.   The radio apparatus according to claim 6 or 7, wherein a non-shielding space is formed on a side opposite to the wall surface of the radiating element held along the wall surface formed of the conductive material. .   The radio apparatus according to claim 1, wherein the flat radiating element is embedded in a wall surface formed of an insulating material or fixed along the wall surface. The wall surface includes a curved surface having a curvature radius of 5 mm or more,
The radio apparatus according to claim 1, wherein the flat radiation elements are arranged along the curved surface. The wireless device includes a transmission / reception circuit connected to the radiating element,
The radio apparatus according to claim 1, wherein the radiating element and the transmission / reception circuit are arranged on the same plane.   The wireless device according to claim 1, wherein at least two of the radiating elements are arranged in the wireless device. In a mobile device mounted on a mobile body,
A wireless device for mounting on a moving body, wherein the wireless device is the wireless device according to any one of claims 1 to 12.   A moving body comprising the wireless device according to claim 1.

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