JP2008078901A - Antenna device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transmit a signal received/amplified by an antenna module to a receiver body even if installing the antenna module in a case having a narrow installation space. <P>SOLUTION: An antenna device 10 installed in the case 120a having the narrow installation space comprises the antenna module 50 installed in the case 120a having the narrow installation space, and a flexible transmission line 60 that has a tip section 60a connected to the antenna module and is led to the outside of the case having the narrow installation space from the tip section. The flexible transmission line 60 has a flexible printed circuit 62 extended in a longitudinal direction. The flexible printed circuit 62 is composed of a triplate line. The flexible printed circuit 62 is covered with a cover 64 made of a flexible material. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an antenna device, and in particular, receives digital radio broadcasts by receiving radio waves from artificial satellites (hereinafter also referred to as “satellite waves”) or radio waves on the ground (hereinafter also referred to as “terrestrial waves”). The present invention relates to an antenna device installed in a narrow space housing such as a car door mirror housing for a digital radio receiver.

  As is well known in this technical field, various antennas are currently mounted on vehicles such as automobiles. For example, one of such antennas is an antenna device for SDARS (Satellite Digital Radio Service).

  SDARS (Satellite Digital Audio Radio Service) is a service by digital broadcasting using a satellite in the United States (hereinafter referred to as “SDARS satellite”). That is, in the United States, digital radio receivers that receive satellite waves or terrestrial waves from SDARS satellites and can listen to digital radio broadcasts have been developed and put into practical use. Currently, in the United States, two broadcasting stations, XM and Sirius, offer a total of more than 250 channels of radio programs nationwide. This digital radio receiver is generally mounted on a moving body such as an automobile, and can receive radio waves by receiving radio waves having a frequency of about 2.3 GHz. That is, the digital radio receiver is a radio receiver capable of listening to mobile broadcasts. Since the frequency of the received radio wave is about 2.3 GHz, the reception wavelength (resonance wavelength) λ at that time is about 128.3 mm. The terrestrial wave is a satellite wave that is once received by the earth station, then slightly shifted in frequency, and retransmitted with linearly polarized waves. That is, satellite waves are circularly polarized while terrestrial waves are linearly polarized.

  The XM satellite radio antenna apparatus receives circularly polarized radio waves (satellite waves) from two geostationary satellites (XM satellites), and receives radio waves (terrestrial waves) by a terrestrial linearly polarized wave facility in a dead zone. On the other hand, the Sirius satellite radio antenna device receives circularly polarized radio waves (satellite waves) from three orbiting satellites (Sirius satellites) (synchronous type), and receives radio waves (terrestrial waves) from the linearly polarized equipment in the dead zone. To do.

  As described above, since radio waves with a frequency of about 2.3 GHz band are used in digital radio broadcasting, an antenna device that receives the radio waves must be installed outdoors. Therefore, when a digital radio receiver is mounted on an automobile, generally, the antenna device is mostly installed on the roof of the automobile.

  This type of antenna device needs to have a wide directivity. This is because, for example, in the case of XM, the digital receiver needs to receive a satellite wave arriving from a relatively low elevation artificial satellite (XM satellite) whose elevation angle is in the range of 20 ° to 60 °. . This is also because the elevation angle of the ground wave is substantially 0 °.

  As antenna elements for an antenna device that receives radio waves having a frequency of about 2.3 GHz band, those having various structures have been proposed. The shape is roughly classified into a planar (flat plate) antenna element that is a patch antenna and a cylindrical antenna element such as a loop antenna and a helical antenna.

  In general, a planar (flat plate) antenna element such as a patch antenna has been considered to be unsuitable for this type of antenna device because of its narrow directivity. However, even if it is a patch antenna, it is known that antenna directivity spreads by using a ground board (earth board) with a large area (for example, refer patent document 1).

  In particular, when a digital radio receiver is mounted on an automobile, as described above, the antenna device is generally attached to the roof of the automobile. In this case, since the roof of the automobile itself acts as a ground plate, it has been confirmed that even if a patch antenna is used as an antenna element, it can be sufficiently used as an antenna device for a digital radio receiver.

  Also, a patch antenna that can ensure antenna directivity at a low elevation angle has been proposed (see, for example, Patent Document 2).

  Nevertheless, a cylindrical antenna is generally used as an antenna element rather than a planar antenna. The reason is that wide directivity is achieved by forming the antenna element in a cylindrical shape. As described above, the cylindrical antenna is roughly classified into a loop antenna and a helical antenna.

  As the loop antenna, an electromagnetic coupling type four-point feeding loop antenna is known (for example, see Patent Document 3). The electromagnetically coupled four-point feed loop antenna disclosed in Patent Document 3 includes a cylindrical body formed by rounding a flexible dielectric film member around a central axis into a cylindrical shape, and a periphery of the cylindrical body. A loop portion formed in a loop shape around the central axis along the surface, and four power supply lines for supplying power to the loop portion formed on the peripheral surface of the cylindrical body. Four electromagnetic coupling lines extending along the four power supply lines from the loop part with gaps therebetween are connected to the four power supply lines, respectively, Power is supplied by electromagnetic coupling. In this loop antenna, a ground conductor pattern is formed on the back surface of a circuit board extending in a direction orthogonal to the central axis.

  On the other hand, a helical antenna is also known (see, for example, Patent Document 4). In Patent Document 4, an antenna pattern composed of four helical conductors is printed on one surface of a flexible dielectric film member (hereinafter referred to as “dielectric film member with an antenna pattern”). It has been proposed to manufacture a helical antenna by rounding a dielectric film member with an antenna pattern into a cylindrical shape around a central axis so that the one surface is an outer peripheral surface. Also in such a helical antenna, a ground conductor pattern is formed on the back surface of the circuit board extending in a direction orthogonal to the central axis.

  In the case of such a cylindrical antenna, a plurality of satellite waves (circularly polarized waves) received from the loop portion via four electromagnetic coupling wires or received by a helix lead wire are phase-shifted by a phase shifter. Are combined by adjusting (adjusting) the phases to each other, amplified by a low noise amplifier (LNA), and sent to the receiver body via a coaxial cable. Here, the combination of the helical antenna, the phase shifter, and the LNA is called an antenna module.

  In addition, a helical antenna formed by forming an antenna pattern on the outer peripheral surface of the cylindrical member, and a phase shifter pattern formed continuously (connected) to the antenna pattern on the outer peripheral surface of the cylindrical member. An antenna element including a phase shifter has also been proposed (see, for example, Patent Document 5).

  Such an antenna element is called a pole-type antenna element because it has a cylindrical body (cylindrical member) formed by rolling a flexible dielectric film member around a central axis into a cylindrical shape.

  When the antenna device is attached to the roof of the automobile, the signal received and amplified by the antenna module is transmitted to the receiver main body installed in the automobile via the coaxial cable as described above ( For example, see Patent Document 6).

  In addition, although it is not a SDARS antenna apparatus, the antenna apparatus for GPS reception suitable for installation outside a vehicle is also known (for example, refer patent document 7). The antenna device disclosed in Patent Document 7 includes an antenna case in which a top cover and a bottom plate are joined, an antenna module that is received in the top cover and receives a GPS signal, and a joint between the top cover and the bottom cover. And a packing member that secures the sealing property of the antenna case. The antenna module includes an antenna element that receives a GPS signal transmitted from a GPS satellite, and a circuit board on which a processing circuit that performs various signal processing such as signal amplification on the GPS signal received by the antenna element is formed; A shield case for shielding the processing circuit. The antenna element and the circuit board are joined by a double-sided tape or the like. The processing circuit includes the above-described low noise amplifier (LNA). The antenna module is connected to the tip of a coaxial cable, and the coaxial cable is drawn out from the antenna case.

JP 2003-163521 A JP 2005-160050 A JP 2003-298335 A JP 2003-37430 A JP 2001-339228 A JP 2005-112082 A JP-A-2005-109687

  As described above, when a digital radio receiver is mounted on an automobile, generally, the antenna device is mostly installed on the roof of the automobile. In this case, the signal received and amplified by the antenna module is transmitted to the receiver main body installed in the vehicle through the coaxial cable.

  On the other hand, it is considered to install the antenna device in a door mirror of an automobile. In this case, the antenna module is installed in the door mirror casing. Since the housing of the door mirror also serves as the antenna case, a dedicated antenna case and packing member (waterproof packing) are not necessary.

  When an antenna device is to be installed in a door mirror, in the conventional antenna device structure, as described above, the signal received and amplified by the antenna module is transmitted from the door mirror provided outside the vehicle to the interior of the vehicle. It is necessary to transmit to the receiver main body installed in the center via a coaxial cable. Further, since the door mirror has a structure that opens and closes with respect to the vehicle body of the automobile, many components such as a motor drive and a motor are incorporated in the door mirror. Therefore, the gap that can be used inside the door mirror housing is very narrow. That is, the door mirror housing is a housing having a narrow installation space (hereinafter referred to as “narrow installation space housing”).

  Therefore, it is extremely difficult to transmit the signal received and amplified by the antenna module from the door mirror (narrow installation space housing) to the receiver body via the coaxial cable. This is because the coaxial cable has a relatively thick cylindrical shape, so that the coaxial cable cannot be bent with a small radius of curvature within the narrow gap. In other words, the coaxial cable is inferior in flexibility. Therefore, when the antenna module of the antenna device is installed in a door mirror (narrow installation space housing), it is not preferable to use only a coaxial cable as a cable (transmission line) for connecting the antenna module and the receiver body. .

  In order to cope with this, it is conceivable to use a flexible cable (transmission line) as the cable (transmission line). Even if such a flexible cable (transmission line) is used, since the automobile is used outdoors, the cable (transmission line) is required to have weather resistance that can withstand dirt and oil. Furthermore, vibration may be applied inside the door mirror (narrow installation space housing), and the cable (transmission line) may come into contact with other parts. Therefore, the cable (transmission line) to be used must be able to withstand damage even in such a case.

  Therefore, an object of the present invention is to provide an antenna device including a transmission line capable of transmitting a signal received and amplified by the antenna module to the receiver body even when the antenna module is installed in a narrow installation space casing. Is to provide.

  Another object of the present invention is to provide an antenna device having a transmission line excellent in weather resistance.

  Still another object of the present invention is to provide an antenna device including a transmission line that is not damaged even if vibration is applied inside a narrow installation space casing.

  According to the present invention, an antenna device installed in a narrow installation space casing (120a), the antenna module (50; 50A) installed in the narrow installation space casing (120a), and the antenna An antenna device (10; 10A) having a tip (60a) connected to the module and a flexible transmission line (60) led out from the tip to the outside of the narrow space housing Is obtained.

  In the antenna device (10; 10A), the flexible transmission line (60) preferably includes a flexible printed circuit (62) extending in the longitudinal direction. The flexible printed circuit (62) may be composed of a triplate line. The triplate line (62) includes a pair of insulating sheets (621, 622) extending in the longitudinal direction and in close contact with each other, and a signal provided between inner surfaces of the pair of insulating sheets. A line (624) and a pair of ground patterns (626, 627) formed on the outer surfaces of the pair of insulating sheets, respectively. The flexible transmission line (60) preferably further includes a cover (64) made of a flexible material that covers the flexible printed circuit (62). The cover (64) is made of, for example, a synthetic rubber such as ethylene, propylene, diene, methylene, and rubber.

  In the antenna device (10; 10A), the antenna module (50; 50A) has an upper surface (30a) and a lower surface (30b) facing each other, and a circuit board (30 on which a processing circuit is mounted on the lower surface). ), An antenna element (20; 80) mounted on the upper surface of the circuit board, and a shield cover (40) attached to the lower surface of the circuit board so as to cover the processing circuit.

  The antenna element may be composed of a pole type antenna element (20) extending in the vertical direction along the central axis. The pole antenna element (20) includes a cylindrical body (20b) in which a flexible dielectric film member (20a) is formed in a cylindrical shape around the central axis, and an upper portion of the cylindrical body. An antenna pattern (20A) formed of a plurality of conductors formed on the peripheral surface of the tube, and a phase shifter pattern formed by being electrically connected to the antenna pattern on the peripheral surface of the cylindrical body at the bottom of the cylindrical body (20P). The antenna pattern (20A) includes a helical pattern (20H) formed in a spiral shape in the central axis direction, and a loop pattern connected to the end of the helical pattern at the upper end of the cylindrical body ( 20L). The helical pattern (20H) preferably has a bent portion bent in the opposite direction at least once in the central axis direction. In the helical pattern (20H), it is desirable that at least a part of the spirally extending portion is formed in a meander shape. The antenna pattern (20A) and the phase shifter pattern (20P) may be formed on the inner peripheral surface (20-1) of the cylindrical body. In this case, the pole type antenna element (20) further includes a ground pattern (27) formed on the outer peripheral surface (20-2) of the cylindrical body and on the surface corresponding to the place where the phase shifter pattern is formed. You may have.

  The antenna element may comprise a planar antenna element (80). The planar antenna element may be composed of a patch antenna (80). In this case, it is preferable that the antenna module (50A) further includes a ground plate (90) provided on the lower surface of the shield cover.

  In addition, the code | symbol in the said parenthesis is attached | subjected in order to make an understanding of this invention easy, and it is only an example, and is not limited to these.

  The antenna device according to the present invention has a distal end portion connected to the antenna module and includes a flexible transmission line led out from the distal end portion to the outside of the narrow installation space casing. The amplified signal can be transmitted to the receiver body. Further, the flexible transmission line is composed of a flexible printed circuit extending in the longitudinal direction and a cover made of a flexible material that covers the flexible printed circuit, thereby providing excellent weather resistance. Further, it is possible to provide a transmission line that is not damaged even if vibration is applied inside the narrow installation space casing.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  An automobile 100 to which the present invention is applied will be described with reference to FIG. The automobile 100 includes a door 110, and a door mirror 120 is attached to the door 110 outside the automobile 100.

  Door mirror 120 has a structure that can be opened and closed with respect to the body of automobile 100. The door mirror 120 includes a housing 120a, and a motor 122 for opening and closing the door mirror 120 and a motor drive (not shown) for driving the motor 122 are installed in the housing 120a. Therefore, the housing 120a of the door mirror 120 is a narrow installation space housing.

  In the casing 120a of the door mirror 120, the antenna device 10 according to the present invention is installed above the motor 122. That is, the illustrated antenna device 10 is a door mirror built-in antenna device.

  The door mirror built-in antenna device 10 according to the first embodiment of the present invention will be described with reference to FIG. 2A is a schematic plan view of the antenna device 10, and FIG. 2B is a schematic side view of the antenna device 10.

  The antenna device 10 includes an antenna module 50 installed in a housing 120 a of a door mirror 120 and a flexible transmission line (cable) 60. The flexible transmission line (cable) 60 has a front end portion 60a connected to the antenna module 50, and is led out of the housing 120a of the door mirror 120 from the front end portion 60a. A connector 70 is connected to the other end 60 b of the flexible transmission line (cable) 60. The illustrated flexible transmission line (cable) 60 has a flexible printed circuit 62 extending in the longitudinal direction.

  FIG. 3 is a cross-sectional view of a flexible printed circuit 62 used for a flexible transmission line (cable) 60. The illustrated flexible printed circuit 62 is composed of a triplate line.

  More specifically, the triplate line 62 includes a pair of insulating sheets 621 and 622 extending in the longitudinal direction and in close contact with each other, and a signal line 624 sandwiched between the inner surfaces of the pair of insulating sheets 621 and 622. And a pair of ground patterns 626 and 627 formed on the outer surfaces of the pair of insulating sheets 621 and 622, respectively. The triplate line 62 has the same characteristic impedance of 50Ω as that of the coaxial cable.

  As described above, in the embodiment of the present invention, since the flexible transmission line (cable) 60 is used as the transmission line (cable), the door mirror 120 can be arranged in a narrow gap in the housing 120a. It becomes possible.

  As described above, the flexible transmission line (cable) 60 is required to have weather resistance. Therefore, if the triplate line 62 is used while being exposed, corrosion or the like occurs.

  Therefore, although not shown in FIG. 3, the triplate line 62 is covered with a cover made of a flexible material as described later. This cover is made of, for example, a synthetic rubber such as ethylene, propylene, diene, methylene, rubber (EPDM). This cover is attached to the triplate line 62 by fitting or integral molding.

  Therefore, the flexible transmission line (cable) 60 is excellent in weather resistance. Further, even if vibration is applied inside the housing 120a of the door mirror 120 and the flexible transmission line (cable) 60 comes into contact with another part, the triplate line 62 is covered with the cover, so that the flexible It is possible to prevent the damaging transmission line (cable) 60 from being damaged.

  Next, the antenna device 10 according to the first embodiment of the present invention will be described in more detail with reference to FIG. FIG. 3 is a side view showing the antenna module 50 used in the antenna device 10.

  The illustrated antenna module 50 includes an antenna element 20, a circuit board (LNA board) 30, and a shield cover 40.

  The circuit board (LNA board) 30 has an upper surface 30a and a lower surface 30b facing each other. A processing circuit (not shown) including the low noise amplifier (LNA) is mounted on the lower surface 30 b of the circuit board (LNA board) 30. The processing circuit is covered with a shield cover 40 attached to the lower surface 30 a of the circuit board (LNA substrate) 30. A distal end portion 60 a of the flexible transmission line (cable) 60 is connected to a processing circuit through an opening (not shown) opened in the shield cover 40.

  The illustrated antenna element 20 is composed of a pole type antenna element. The pole type antenna element 20 extends in the vertical direction along the central axis and is mounted on the upper surface 30 a of the circuit board 30.

  Next, the pole type antenna element 20 used in the antenna module 50 of FIG. 4 will be described with reference to FIGS. FIG. 5 is a front view showing the appearance of the pole type antenna element 20. FIG. 6 is a development view of the pole-type antenna element 20 shown in FIG. 5, (A) is a plan view showing the first surface (inner peripheral surface), and (B) shows the second surface (outer peripheral surface). It is a top view.

  The illustrated pole type antenna element 20 has a cylindrical body 20b formed by rolling a flexible dielectric film member 20a as shown in FIG. 6 into a cylindrical shape around a central axis. 6A shows the first surface 20-1 of the dielectric film member 20a, and FIG. 6B shows the second surface 20-2 of the dielectric film member 20a.

  The dielectric film member 20a is manufactured using a film made of a low-loss dielectric material, for example, a Teflon (registered trademark) material. On the first surface 20-1 side of the dielectric film member 20a, an antenna pattern portion 20A and a phase shifter portion 20P are formed on the upper and lower portions, respectively. The antenna pattern portion 20A has a substantially parallelogram shape, and the phase shifter portion 20P has a substantially rectangular shape.

  The antenna pattern portion 20A includes a helical pattern portion 20H formed in a spiral shape in the longitudinal direction (center axis direction) of the pole antenna module 20, and an end portion of the helical pattern portion 20H at the upper end portion of the cylindrical body 20b. The loop pattern portion 20L is connected to the loop pattern portion 20L.

  After the dielectric film member 20a is rounded so that the first surface 20-1 becomes the inner peripheral surface, the cylindrical body 20b as shown in FIG. It is formed. The connection between the pair of sides is performed by, for example, a double-sided adhesive tape, an adhesive, or soldering.

  A first antenna pattern including first to fourth helical conductors 21, 22, 23, and 24 is formed on the first surface 20-1 of the helical antenna portion 20H. Each of the illustrated first to fourth helical conductors 21 to 24 extends in parallel with the side edge in a state where it is bent four times in the opposite direction in the longitudinal direction (center axis direction) of the pole type antenna module 20. Is formed. In particular, in each of the first to fourth helical conductors 21 to 24, at least one of the five conductor patterns extending in parallel with the side edges, here the conductor pattern connected to the phase shifter pattern 25 Are meandering, that is, zigzag meandering.

  As described above, when the dielectric film member 20a is rolled into the cylindrical body 20b, each of the first to fourth helical conductors 21 to 24 is arranged on the inner peripheral surface of the cylindrical body 20b in the longitudinal direction of the pole-type antenna module 20 ( In the state of being bent four times in the opposite direction in the central axis direction), it is formed to extend in a helix shape. The first antenna pattern composed of the first to fourth helical conductors 21 to 24 functions as a helical antenna.

  In such a configuration, each of the first to fourth helical conductors 21 to 24 is bent in the longitudinal direction of the pole-type antenna element 20, and a part of each helical conductor is formed in a meander shape. The length can be increased, and the height of the pole antenna element 20 can be reduced as compared with the case where the helical conductor is not bent.

  On the first surface 20-1 of the loop antenna portion 20L, a second antenna pattern including a loop conductor 28 connected to the tips (upper ends) of the first to fourth helical conductors 21 to 24 is formed. Yes. The second antenna pattern composed of the loop conductor 28 functions as a loop antenna.

  A phase shifter pattern 25 electrically connected to the first antenna pattern is formed on the first surface 20-1 of the phase shifter portion 20P. Therefore, when the dielectric film member 20a is rounded into the cylindrical body 20b as described above, the phase shifter pattern 25 is formed on the inner peripheral surface of the cylindrical body 20b. The phase shifter pattern 25 functions as a phase shifter.

  A ground pattern 27 is formed on the second surface 20-2 of the phase shifter portion 20P. That is, the ground pattern 27 is formed on the surface facing the place where the phase shifter pattern 25 is formed. Therefore, when the dielectric film member 20a is rounded into the cylindrical body 20b as described above, the ground pattern 27 is formed on the outer peripheral surface of the cylindrical body 20b and on the surface opposite to the portion where the phase shifter pattern 25 is formed. It will be. The ground pattern 27 functions as a shield member provided so as to cover the phase shifter pattern 25. The output terminal 25a of the phase shifter pattern 25 is connected to a low noise amplifier (LNA) mounted on the lower surface 30b of the circuit board 30.

  In the antenna module 50 including the pole type antenna element 20 having such a configuration, a plurality of satellite waves (circularly polarized waves) received by the loop conductor 28 of the loop antenna portion 20L and the four conductors 21 to 24 of the helical antenna portion 20H. Waves) are combined by adjusting their phases by shifting their phases by the phase shifter pattern 25, and then synthesized by a low noise amplifier (LNA) mounted on the lower surface 30b of the circuit board 30. Amplified and transmitted to a receiver main body (not shown) installed in the interior of the automobile via the flexible cable 60.

  5 and 6 have been described with reference to an example of the pole type antenna element 20. However, the pole type antenna element 20 is not limited to the above-described embodiment. For example, in the above-described embodiment, four helical conductors formed on the inner peripheral surface of the cylindrical body are used as the first antenna pattern, but may be composed of at least two helical conductors. In the above embodiment, each helical conductor constituting the first antenna pattern is bent in the opposite direction four times in the longitudinal direction (center axis direction) of the pole type antenna module, but is bent in the opposite direction at least once. Good thing. In the said embodiment, although the ground pattern formed in the outer peripheral surface of a cylinder is used as a shielding member, a shielding member is not limited to this, What is necessary is just to be provided so that a phase shifter pattern may be covered.

  A door mirror built-in antenna device 10A according to a second embodiment of the present invention will be described with reference to FIGS.

  The illustrated door mirror built-in antenna device 10A includes an antenna module 50A. The antenna module 50A has a configuration similar to that of the antenna module 50 shown in FIG. 4 except that the configuration of the antenna elements is different as will be described later and a ground plate 90 is added. Accordingly, the antenna element is denoted by reference numeral 80. The door mirror built-in antenna device 10A shown in the figure uses not only a flexible transmission line (cable) 60 but also a coaxial cable 60A as a transmission line. Components having the same functions as those shown in FIG. 4 are given the same reference numerals.

  In the present embodiment, a patch antenna that is a planar antenna element is used as the antenna element 80.

  The patch antenna 80 includes a substantially rectangular parallelepiped dielectric substrate 82, an antenna radiation electrode (radiation element) 84, a ground electrode (ground conductor) (not shown), and a rod-shaped power supply pin (not shown). Is done.

  The dielectric substrate 82 is made of a high dielectric constant ceramic material made of, for example, barium titanate. Dielectric substrate 82 has a top surface 82u and a bottom surface (not shown) facing each other, and side surface 82s. In the illustrated example, the corner of the side surface 82s of the dielectric substrate 82 is chamfered. The dielectric substrate 82 is provided with a substrate through hole (not shown) penetrating from the top surface 82u to the bottom surface at a position where a feeding point 85 described later is installed.

  The antenna radiation electrode (radiation element) 84 is made of a conductive film, and is formed on the top surface 82 u of the dielectric substrate 82. The illustrated antenna radiation electrode (radiation element) 82 has a circular shape, but may have a square shape. The antenna radiation electrode (radiation element) 84 is formed by, for example, silver pattern printing.

  The ground electrode (ground conductor) is made of a conductive film and is formed on the bottom surface of the dielectric substrate 82. The ground electrode (ground conductor) has a ground through hole (not shown) that is substantially concentric with the substrate through hole and has a diameter larger than the diameter of the substrate through hole.

  A feeding point 85 is provided at a position displaced from the center of the antenna radiation electrode 82 in the x-axis direction and the y-axis direction. One end of the power supply pin is connected to the power supply point 85. The power supply pin is separated from the ground electrode (ground conductor) through the substrate through hole and the ground through hole, and the through hole (illustrated) formed in the circuit board 30 protrudes from the lower surface 30b of the circuit board 30. Has been derived.

  Here, solder is used as the feeding point 85. Therefore, the feeding point 85 has a convex shape that rises upward from the main surface of the antenna radiation electrode 84.

  The shield cover 40 is mounted on the main surface 90 a of the ground plate 90. In other words, the ground plate 90 is provided on the lower surface of the shield cover 40.

  In the antenna module 50A including the planar antenna element 80 having such a configuration, the satellite wave (circularly polarized wave) received by the patch antenna 80 is a low noise amplifier (LNA) mounted on the lower surface 30b of the circuit board 30. Is transmitted to a receiver main body (not shown) installed in the vehicle through the flexible cable 60 and the coaxial cable 60A.

  As shown in FIGS. 7 and 8, the flexible transmission line (cable) 60 includes a triplate line 62 (see FIG. 3) and a cover 64 that covers the triplate line 62. As described above, the cover 64 is made of synthetic rubber such as ethylene / propylene / diene / methylene rubber (EPDM). The cover 64 is attached to the triplate line 62 by fitting or integral molding.

  The distal end portion 60 a of the flexible transmission line (cable) 60 is connected to the processing circuit via the opening 40 a opened in the shield cover 40.

  The other end of the flexible transmission line (cable) 60 is connected to one end of the coaxial cable 60A via a connecting member 200 described later, and the other end 60Ab of the coaxial cable 60A is connected to the connector 70. .

  With reference to FIGS. 9 and 10, an example of the connection member 200 that connects the other end 60b of the flexible transmission line (cable) 60 and the one end 60Aa of the coaxial cable 60A will be described. 9 is a perspective view of the connection member 200 as viewed from the front surface side, and FIG. 10 is a perspective view of the connection member 200 as viewed from the back surface side. The illustrated connecting member 200 is composed of solders 202 and 204. 9 and 10, the illustration of the cover 64 that covers the triplate line 62 is omitted.

  More specifically, as is well known, the coaxial cable 60A is a coaxial electric signal transmission medium including a cylindrical outer conductor (earth network) 61A and a central conductor (core wire) 62A at the center thereof. The outer conductor (earth net) 61A and the center conductor (core wire) 62A are insulated by a cylindrical insulator 63A. The outer conductor (earth net) 61A is covered with a sheath (outer skin) 64A.

  At the other end 60b of the flexible transmission line (cable) 60 and one end 60Aa of the coaxial cable 60A, the signal line 624 of the triplate line 62 is connected to the central conductor (core line) 62A of the coaxial cable 60A by the solder 202. The ground pattern 626 of the triplate line 62 is directly electrically connected to the outer conductor (earth network) 61A of the coaxial cable 60A by the solder 204.

  In the example shown in FIGS. 9 and 10, only the ground pattern 626 on the lower side of the triplate line 62 is illustrated as being connected to the outer conductor (earth network) 61A of the coaxial cable 60A by the solder 204. However, it goes without saying that the ground pattern 627 on the upper side of the triplate line 62 is also connected to the outer conductor (earth network) 61A of the coaxial cable 60A by solder (not shown).

  Further, as shown in FIGS. 7 and 8, the connecting member 200 has the solder described above straddling the other end 60b of the flexible transmission line (cable) 60 and the one end 60Aa of the coaxial cable 60A. A cover 220 covering 202 and 204 is also provided.

  Anyway, in the connection member 200 shown in FIGS. 9 and 10, the other end portion 60b of the flexible transmission line (cable) 60 and the one end portion 60Aa of the coaxial cable 60A are directly connected using the solders 202 and 204. is doing.

  With reference to FIG. 11, another connecting member 200A for connecting the other end portion 60b of the flexible transmission line (cable) 60 and the one end portion 60Aa of the coaxial cable 60A will be described. FIG. 11 is a perspective view of the connecting member 200A as seen from the front side. In FIG. 11, illustration of the cover 64 covering the triplate line 62 is omitted.

  At the other end 60b of the flexible transmission line (cable) 60 and one end 60Aa of the coaxial cable 60A, the signal line 624 of the triplate line 62 is connected to the coaxial cable 60A by the solders 202 and 206 via the cable 212. The ground pattern 626 of the triplate line 62 is electrically connected to the outer conductor (earth network) 61A of the coaxial cable 60A by the solder 204 and 208 via the cable 214. It is connected.

  In the example shown in FIG. 11, only the ground pattern 626 on the lower side of the triplate line 62 is illustrated as being connected to the outer conductor (earth network) 61 </ b> A of the coaxial cable 60 </ b> A via the cable 214. Of course, the ground pattern 627 on the upper side of the triplate line 62 is also connected to the outer conductor (earth network) 61A of the coaxial cable 60A via a cable (not shown).

  Anyway, in the connecting member 200A shown in FIG. 11, the other end 60b of the flexible transmission line (cable) 60 and the one end 60Aa of the coaxial cable 60A are used, and the cables 112 and 114 and the solders 202 and 204 are used. Connected.

  As mentioned above, although this invention has been demonstrated by embodiment, it cannot be overemphasized that this invention is not limited to embodiment mentioned above. For example, the antenna device described in the above embodiment is suitable for an antenna device for receiving SDARS signals, but is not limited to this, and an antenna device for receiving GPS (Global Positioning System) signals, The present invention is also applicable as an antenna device for mobile communication for receiving other satellite waves and terrestrial waves. Further, the antenna device according to the above-described embodiment has been described by taking an example in which the narrow installation space housing is a housing of an automobile door mirror, but the narrow installation space housing is limited to the door mirror housing. Of course, other casings such as a radio cassette may be used.

1 is a side view showing a part of an automobile to which an antenna device according to the present invention is applied. It is a figure which shows the antenna device which concerns on the 1st Embodiment of this invention built in the door mirror of the motor vehicle shown in FIG. 1, (A) is a schematic plan view of an antenna device, (B) is an antenna device. FIG. It is sectional drawing which shows the flexible printed circuit used for the flexible transmission line (cable) which comprises the antenna apparatus shown in FIG. It is a side view which shows the antenna module used for the antenna apparatus shown in FIG. It is a front view which shows the external appearance of the pole type | mold antenna element used for the antenna module shown in FIG. FIG. 6 is a development view of the pole-type antenna element shown in FIG. 5, where (A) is a plan view showing a first surface (inner peripheral surface), and (B) is a plan view showing a second surface (outer peripheral surface). . It is a perspective view which shows the antenna device which concerns on the 2nd Embodiment of this invention. It is a perspective view which shows the antenna apparatus shown in FIG. It is the perspective view which looked at the connection member which connects the other end part of a flexible transmission line (cable) and the one end part of a coaxial cable used in the antenna apparatus shown in FIG.7 and FIG.8 from the surface side. . It is the perspective view which looked at the connection member shown in FIG. 9 from the back surface side. The perspective view which looked at the other connection member used in the antenna apparatus shown in FIG.7 and FIG.8 which connects the other end part of a flexible transmission line (cable), and the one end part of a coaxial cable from the surface side. It is.

Explanation of symbols

10, 10A Antenna device 20 Pole type antenna element 20a Flexible dielectric film member 20b Tubular body 20A Antenna pattern portion 20H Helical antenna portion 20L Loop antenna portion 20P Phase shifter portion 20-1 First surface (inner peripheral surface)
20-2 Second surface (outer peripheral surface)
21-24 Helical conductor (first antenna pattern)
25 Phase shifter pattern (phase shifter)
27 Ground pattern (shield member)
28 Loop conductor (second antenna pattern)
30 Circuit board (LNA board)
30a Upper surface 30b Lower surface 40 Shield cover 50, 50A Antenna module 60 Flexible transmission line (cable)
60a Tip 62 Flexible printed circuit (Triplate line)
621, 622 Insulating sheet 624 Signal line 626, 627 Ground pattern 64 Cover made of flexible material 80 Planar antenna element (patch antenna)
90 Ground board

Claims (16)

An antenna device installed in a narrow installation space housing,
An antenna module installed in the narrow installation space casing;
A flexible transmission line having a tip connected to the antenna module and led out of the narrow space housing from the tip;
An antenna device comprising:   The antenna apparatus according to claim 1, wherein the flexible transmission line includes a flexible printed circuit extending in a longitudinal direction.   The antenna apparatus according to claim 1, wherein the flexible printed circuit includes a triplate line.   The triplate line includes a pair of insulating sheets that extend in the longitudinal direction and are in close contact with each other, a signal line that is sandwiched between inner surfaces of the pair of insulating sheets, and the pair of insulating sheets The antenna device according to claim 3, further comprising a pair of ground patterns respectively formed on an outer surface of the sheet.   The antenna device according to claim 2, wherein the flexible transmission line further includes a cover made of a flexible material that covers the flexible printed circuit.   The antenna device according to claim 5, wherein the cover is made of synthetic rubber.   The antenna device according to claim 6, wherein the synthetic rubber is ethylene / propylene / diene / methylene rubber. The antenna module is
A circuit board having an upper surface and a lower surface facing each other, and a processing circuit mounted on the lower surface;
An antenna element mounted on the upper surface of the circuit board;
A shield cover attached to the lower surface of the circuit board so as to cover the processing circuit;
The antenna device according to claim 1, comprising:   The antenna device according to claim 8, wherein the antenna element is a pole type antenna element extending in a vertical direction along a central axis. The pole antenna element is
A cylindrical body in which a flexible dielectric film member is formed in a cylindrical shape around the central axis;
An antenna pattern composed of a plurality of conductors formed on the peripheral surface of the cylindrical body at the top of the cylindrical body;
A phase shifter pattern formed at the lower part of the cylindrical body and electrically connected to the antenna pattern on the peripheral surface of the cylindrical body;
The antenna device according to claim 9, comprising:   The antenna pattern is composed of a helical pattern formed to extend spirally in the central axis direction, and a loop pattern connected to the end of the helical pattern at the upper end of the cylindrical body. The antenna device according to claim 10, wherein:   The antenna device according to claim 11, wherein the helical pattern has a bent portion bent in the opposite direction at least once in the central axis direction.   The antenna device according to claim 11 or 12, wherein at least a part of the helical pattern of the helical pattern has a meander shape. The antenna pattern and the phase shifter pattern are formed on the inner peripheral surface of the cylindrical body,
The antenna device according to any one of claims 10 to 13, further comprising a ground pattern formed on an outer peripheral surface of the cylindrical body and a surface corresponding to a place where the phase shifter pattern is formed.   The antenna device according to claim 8, wherein the antenna element is a planar antenna element. The planar antenna element comprises a patch antenna;
The antenna device according to claim 15, wherein the antenna module further includes a ground plate provided on a lower surface of the shield cover.

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