JP2007158955A - On-vehicle antenna system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact on-vehicle antenna system with a simple structure that is easily manufactured while attaining multi-functions by locating a preamplifier of an external antenna and taking into account the connection to a signal cable and the shield countermeasures. <P>SOLUTION: The antenna system 1 includes: antenna elements 3, 4 arranged in the middle of a circuit board 2; the preamplifier for the external antenna 20 and a connector terminal 10 of the preamplifier arranged in the vicinity of a side edge of the circuit board 2; and a sheet metal frame body 7 for supporting the circuit board 2 and rectangularly surrounding the antenna elements 3, 4 by side plates 71, 72. A notched groove 75 is formed to the side plate 72 of the frame body 7, a folded tongue 77 inwardly obliquely extended from the notched groove 75 is provided, and the signal cable 21 for the external antenna 20 inserted into the notched groove 75 is guided by the folded tongue 77 and led to the connector terminal 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a small in-vehicle antenna device in which a preamplifier for an external antenna is disposed on a circuit board on which an antenna element is mounted.

In recent years, it has become common to install a receiving antenna for GPS (Global Positioning System), a transmitting / receiving antenna for ETC (Automatic Toll Collection System), and the like in a passenger compartment of an automobile. As a conventional example of such an in-vehicle antenna device, a circuit board mounted with a dielectric patch antenna is housed in a radome and is widely used on a dashboard or the like. For example, see Patent Document 1). As another conventional example, there has been proposed a configuration in which a radiation conductor is patterned on a glass surface of a vehicle and a preamplifier is fixedly connected to each other (for example, see Patent Document 2).
Japanese Patent Laying-Open No. 2004-228802 (page 4-8, FIG. 6) JP-A-7-99405 (page 3, FIG. 1)

  By the way, as a vehicle-mounted antenna device, in addition to a small GPS antenna and an ETC antenna, a diversity antenna for receiving a terrestrial wave transmitted from a base station is expected to have high demand. If a plurality of different types of antenna devices are independently arranged in the vehicle interior, the mounting operation becomes complicated and the appearance is poor. Accordingly, the present inventors have studied to provide a multi-function capable of consolidating the antenna mechanism by disposing a preamplifier for an external antenna such as a diversity antenna on a circuit board of a small antenna device such as a GPS. However, in that case, the small antenna device is previously provided with a shield member for electromagnetically shielding the preamplifier for the external antenna, and for easily connecting the signal cable of the external antenna to the preamplifier. Since it is necessary to provide a cable connection mechanism, there is a problem that the number of parts increases and the structure becomes complicated unless special measures are taken.

  The present invention has been made in view of such a state of the art, and an object of the present invention is to incorporate a preamplifier for an external antenna and to make it multifunctional in consideration of connection with a signal cable and shielding measures. An object of the present invention is to provide a small in-vehicle antenna device that is simple in structure and easy to manufacture.

  In order to achieve the above object, in the vehicle-mounted antenna device of the present invention, a metal having a circuit board on which an antenna element is mounted and a side plate extending along the edge of the circuit board and holding the circuit board. A frame made of a plate, a preamplifier for an external antenna disposed near the edge of the circuit board, and a connector terminal of the preamplifier, the frame having an inward direction from the side plate A bent tongue formed as a cut and raised piece extending obliquely and engageable with one surface of the circuit board in the vicinity of the connector terminal, and a space generated in the side plate by the cut and raised of the bent tongue. The external antenna signal cable inserted into the notch groove is guided by the bent tongue and guided to the connector terminal.

  In the vehicle-mounted antenna device configured as described above, a preamplifier for an external antenna having a different use from the antenna element mounted on the circuit board is disposed on the circuit board. The antenna mechanism can be consolidated by connecting the output end of the signal cable of the external antenna to the terminal. Further, since the sheet metal frame holds the circuit board by engaging the bent tongue or the like, the preamplifier can be electromagnetically shielded by the frame, and the frame The signal cable can be smoothly guided to the corresponding connector terminal without any risk of damage by the cutout groove or the bent tongue of the side plate. Therefore, this in-vehicle antenna device can avoid the generation of noise due to the external antenna and the complicated installation work even if the structure is not complicated.

  In the above configuration, when the external antenna is a pair of diversity antennas, the pair of connector terminals for connecting the signal cables of these diversity antennas are arranged in the vicinity of the pair of edges extending substantially parallel to the circuit board. And a pair of side plates extending along the pair of edges to extend inwardly bent tongues, thereby providing a pair of front antennas for each diversity antenna. The amplifier and its connector terminals can be arranged on both sides of the circuit board in a balanced manner.

  In the above configuration, when the frame body is provided with an engagement piece that extends inward from the side plate and can be engaged with the other surface of the circuit board, the circuit board is bent and the engagement piece. And can be held easily and reliably in the thickness direction.

  In addition, in the above configuration, when the frame is provided with a partition plate disposed between the side plate and the antenna element, a preamplifier for an external antenna is disposed between the partition plate and the side plate. However, the antenna element is not adversely affected.

  The in-vehicle antenna device of the present invention is multi-functionalized by disposing a preamplifier for an external antenna on a circuit board on which an antenna element is mounted. The preamplifier can be electromagnetically shielded, and the signal cable of the external antenna can be smoothly guided to the corresponding connector terminal by the bent tongue of the frame body without any risk of damage. Even if the structure is not complicated, it is possible to avoid generation of noise due to the external antenna and complicated installation work. Therefore, it is possible to manufacture a small in-vehicle antenna device that can effectively consolidate antenna mechanisms at low cost.

  An embodiment of the invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view of a vehicle-mounted antenna device according to an embodiment of the present invention, FIG. 2 is a front view of the antenna device, and FIG. FIG. 4 is a front perspective view corresponding to FIG. 3, and FIG. 5 is a rear view showing a state in which a signal cable of a diversity antenna is connected to the antenna device. 6 is an explanatory diagram in which the signal cable and the bracket are omitted from FIG. 5 and the cable insertion portion is clearly shown, and FIG. 7 is a rear view showing the overall arrangement of the antenna device and the diversity antenna. FIG. 8 is a front view corresponding to FIG.

  The antenna device 1 shown in these drawings is an in-vehicle antenna device that is used by being mounted on a surface on the passenger compartment side of a glass surface 50 (see FIGS. 7 and 8) such as a windshield of an automobile. It can be attached to the center of the upper end. The antenna device 1 includes a circuit board 2 provided with a ground conductor layer and a feeding circuit (not shown), a GPS antenna element 3 and an ETC antenna element 4 mounted on one surface (front surface) of the circuit board 2. A shield cover 5 mounted on the other surface (back surface) of the circuit board 2, a connector portion 6 fixed to one end of the circuit board 2 and connected to an external circuit such as a transmission / reception circuit, and the circuit board 2. A sheet metal frame 7 that holds and surrounds the antenna elements 3, 4, a sheet metal bracket 8 that is fastened and fixed to the frame 7 using three fixing screws 9, and an external that receives terrestrial digital waves A preamplifier (not shown) for an antenna and a connector terminal 10 of the preamplifier are schematically configured. In other words, the antenna device 1 is an integrated antenna device having both a GPS antenna and an ETC antenna, and a multi-function incorporating a preamplifier of a pair of diversity antennas 20 (see FIGS. 7 and 8) as external antennas. Antenna device.

  The circuit board 2 is provided with a ground conductor layer in a region facing the antenna elements 3 and 4, and an electronic circuit portion (including a feeding circuit) for the antenna elements 3 and 4 in a region covered with the shield cover 5. ) Is provided. A preamplifier for each diversity antenna 20 and a connector terminal 10 of the preamplifier are disposed on the left and right edges of the circuit board 2, and two corners of the circuit board 2 are cut out. Each connector terminal 10 is mounted in the vicinity of the relief portion 2a formed. In addition, a through hole 2b through which one fixing screw 9 is inserted is formed at a substantially center near the connector portion 6 of the circuit board 2, and a peripheral portion of the through hole 2b is formed by a head portion of the fixing screw 9. Is pressed and fixed.

  The antenna element 3 is a sheet metal patch antenna formed by pressing a metal plate or the like, and is manufactured as a two-point feed type circularly polarized patch antenna suitable for receiving GPS signals. The antenna element 3 includes a radiating conductor plate 35 made of a metal flat plate in which a square opening 30 is formed in the center and first to fourth cutouts 31 to 34 are formed at four equally spaced outer edges, The first power supply leg piece 36 and the second power supply formed as a pair of cut and raised pieces extending from the innermost portions of the first and second cutouts 31 and 32 of the radiation conductor plate 35 to the circuit board 2 side. The circuit board includes four leg pieces 37, four attachment leg pieces 38 formed as cut-and-raised pieces extending from the four corners of the radiation conductor plate 35 to the circuit board 2 side, and four equidistant positions on the periphery of the opening 30. And four short-circuit leg pieces 39 formed as cut-and-raised pieces extending to the two sides. Here, the radiation conductor plate 35 faces the ground conductor layer on the circuit board 2 with a predetermined interval, and each short-circuit leg piece 39 is soldered to the ground conductor layer. The pair of power supply leg pieces 36 and 37 penetrates the circuit board 2 without contact with the ground conductor layer, and is connected to the power supply circuit in a region covered with the shield cover 5. Further, each mounting leg piece 38 penetrates the circuit board 2 without contact with the ground conductor layer and is soldered to a land (not shown) in an area covered by the shield cover 5. Capacitance is loaded between the conductor layers and contributes to the miniaturization of the antenna element 3. As described above, the four places of the outer edge portion and the four places of the inner edge portion of the radiating conductor plate 35 are held in a balanced manner by the mounting leg piece 38 and the short-circuit leg piece 39, respectively. Is supported.

  The outer shape of the radiation conductor plate 35 is a substantially regular octagon, and the central portion of each side excluding the four corner sides where the mounting leg pieces 38 exist is cut inwardly (in the radial direction) to form first to fourth cutouts 31 to 31. 34. And since the innermost part of the 1st notch 31 is a base end part of the 1st electric power feeding leg piece 36, it becomes the 1st electric power feeding part P1, and the innermost part of the 2nd notch 32 is similarly 2nd. Since it is the base end portion of the power feeding leg piece 37, it becomes the second power feeding portion P <b> 2. The pair of power feeding portions P1 and P2 are supplied with power feeding signals whose phases are shifted by 90 degrees, so that the radiating conductors are in two resonance modes that are electrically and spatially orthogonal and have the same amplitude. The plate 35 can resonate to emit circularly polarized waves.

  However, the antenna device 1 is provided with a sheet metal frame 7 for electromagnetically shielding the preamplifier of the diversity antenna 20, and this frame 7 operating as a ground is different from the antenna element 3. Since the antenna element 3 is surrounded, the axial ratio of the antenna element 3 may slightly deteriorate due to the influence of the frame body 7. Therefore, in this embodiment, the cut amount of the first and third cutouts 31 and 33 is made slightly deeper than the cut amount of the second and fourth cutouts 32 and 34, and the diameter dimension D1 shown in FIG. The axial ratio deterioration caused by the frame body 7 is corrected by setting it to be appropriately shorter than the diameter dimension D2. That is, the side plates 71 and 72 of the frame body 7 surrounding the antenna element 3 in a rectangular shape have a pair of side plates 71 on the long side extending along the cutting direction of the first and third cutouts 31 and 33. Moreover, since the pair of side plates 72 on the short side extends along the cutting direction of the second and fourth cutouts 32 and 34, when the radiating conductor plate 35 is excited, compared to the resonance mode along the side plate 71. The resonance mode along the side plate 72 is more strongly affected by the ground. If the diameter D1 is equal to the diameter D2, the resonance frequency of both modes is different and the axial ratio is deteriorated. However, if the diameter dimension D1 is set to be appropriately shorter than the diameter dimension D2, the deterioration of the axial ratio can be corrected. The frame body 7 is provided with a pair of partition plates 73 in parallel with the side plates 72 on the short side, and by arranging these partition plates 73 between the side plates 72 and the antenna element 3, a shielding effect can be obtained. Therefore, the antenna element 3 can be arranged in a substantially square space defined by the side plate 71 and the partition plate 73, and this also suppresses deterioration of the axial ratio caused by the frame body 7. Yes.

  The antenna element 4 is a sheet metal patch antenna formed by pressing a metal plate or the like, and is manufactured as a two-point feeding type circularly polarized patch antenna suitable for receiving an ETC signal. Compared to 3, it has a small diameter and a low profile. The antenna element 4 includes a radiating conductor plate 41 made of a flat metal plate and having cutouts 42 at four equally spaced outer edge portions, and two notch portions that are 90 ° apart from the outer edge portion of the radiating conductor plate 41. The first power supply leg piece 43 and the second power supply leg piece 44 formed as a pair of cut-and-raised pieces extending from the innermost portions of the circuit board 2 to the circuit board 2 side, and the circuit board from the four corners of the radiation conductor plate 41 The radiating conductor plate 41 protrudes into the opening 30 of the antenna element 3 for GPS. Further, the pair of power supply leg pieces 43 and 44 penetrates the circuit board 2 in a non-contact manner with the ground conductor layer and is connected to the power supply circuit in a region covered with the shield cover 5. Further, each mounting leg piece 45 penetrates the circuit board 2 without contact with the ground conductor layer and is soldered to a land (not shown) in a region covered with the shield cover 5. Capacitance is loaded between the conductor layer and the antenna element 4 is reduced in size. As described above, since the four portions of the outer edge portion of the radiation conductor plate 41 are held in a balanced manner by the mounting leg pieces 45, the antenna element 4 is stably supported on the circuit board 2.

  The radiating conductor plate 41 of the antenna element 4 is opposed to the ground conductor layer on the circuit board 2 with a predetermined interval, but compared with the interval between the circuit board 2 and the radiating conductor plate 35 of the antenna element 3, The distance between the circuit board 2 and the radiation conductor plate 41 is narrow. That is, the radiating conductor plate 41 is smaller in height than the radiating conductor plate 35 having the opening 30. By doing so, two types of antenna elements 3 and 4 having different tuning frequencies can be arranged on the circuit board 2 in a space-efficient manner, and also due to interference of radio waves radiated from the radiation conductor plates 35 and 41. Generation of noise can be suppressed. Since the antenna element 3 is provided with four short-circuit leg pieces 39 so as to surround the antenna element 4, both the antenna elements 3 and 4 are electromagnetically coupled by the shielding effect of the short-circuit leg pieces 39. Isolation is enhanced.

  Each side plate 72 on the short side of the frame 7 is formed with a notch 74 having an open end on the bracket 8 side and a substantially L-shaped notch groove 75 having an open end on the side opposite to the bracket 8. The frame 7 is formed with a connecting piece 76, a bent tongue piece 77, and a locking piece 78 as bent and raised pieces extending inwardly from the side plates 72. The connecting piece 76 is a cut-and-raised piece having a screw insertion hole 76 a and a receiving portion 76 b, and is bent at a substantially right angle with respect to the side plate 72. The connecting piece 76 has a screw insertion hole 76a and a peripheral edge thereof protruding into the escape portion 2a of the circuit board 2, but the receiving portion 76b is engaged with the circuit board 2 from the bracket 8 side in the vicinity of the escape portion 2a. Yes. The bent tongue piece 77 is a cut-and-raised piece extending obliquely inward from the side plate 72 and is engaged with the circuit board 2 from the side opposite to the bracket 8, and the distal end portion of the bent tongue piece 77 is a connector. It is located in the vicinity of the terminal 10. The locking piece 78 is a cut-and-raised piece extending inwardly from the side plate 72 in a substantially C shape, and is engaged with the circuit board 2 from the bracket 8 side. Thus, since the left and right edges of the circuit board 2 are sandwiched in the plate thickness direction by the connecting piece 76, the locking piece 78, and the bent tongue piece 77, the frame body 7 can easily and reliably hold the circuit board 2. Can be held in. The frame body 7 is connected to a ground circuit of the circuit board 2 by soldering.

  Further, the notch 74 of the frame body 7 is generated in the side plate 72 by cutting and raising the connecting piece 76, and when the leading end portion (nut portion 82 a) of the standing piece 82 of the bracket 8 is inserted into the notch 74. The connecting piece 76 and the nut portion 82a overlap each other, and a screw screw hole 82b formed in the nut portion 82a communicates with the screw insertion hole 76a of the connecting piece 76. Then, by fixing the fixing screw 9 inserted into the screw insertion hole 76a from the side opposite to the bracket 8 into the screw screw hole 82b, the two standing pieces 82 of the bracket 8 are respectively connected to the corresponding connecting pieces 76 of the frame body 7. It is fastened and fixed to.

  The cutout groove 75 of the frame body 7 is a substantially L-shaped cutout including a space generated in the side plate 72 when the bent tongue piece 77 is cut and raised, and the signal channel of the diversity antenna 20 inserted into the cutout groove 75. The bull 21 is guided by the bent tongue 77 and guided to the connector terminal 10. That is, as shown in FIGS. 7 and 8, since a pair of diversity antennas 20 are arranged as, for example, film antennas on the left and right sides of the upper center portion of the glass surface 50 on which the antenna device 1 is mounted, It is necessary to connect the output end portion of the signal cable 21 derived from the diversity antenna 20 to the pair of connector terminals 10 mounted on the circuit board 2. The cutout groove 75 and the bent tongue piece 77 provided in the frame body 7 are for smoothly connecting the signal cable 21. Further, since the signal cable 21 guided along the bent tongue 77 can avoid contact with the sharp edge of the metal plate, there is no possibility that the signal cable 21 is damaged due to vibration during traveling.

  The bracket 8 has a square bowl-shaped plate 81 that defines a square opening 80 through which the radiation conductor plate 35 protrudes, and the frame body 7 stands up from three places of the bowl-shaped plate 81 toward the circuit board 2. And an L-shaped standing piece 82 fastened and fixed to the circuit board 2. One surface of the bowl-shaped plate 81 is fixed to the glass surface 50 with an adhesive or the like, and covers the side plates 71 and 72 and the partition plate 73 of the frame body 7 from the glass surface 50 side. Further, each standing piece 82 is formed with a nut portion 82a having a screw screw hole 82b for screwing the fixing screw 9, and the nut portions 82a of the two standing pieces 82 at symmetrical positions are The nuts 82a of the remaining standing piece 82 are fastened and fixed to the corresponding connecting pieces 76 of the frame 7, and the nuts 82a of the remaining one standing piece 82 are fastened and fixed to the peripheral part of the through hole 2b of the circuit board 2 and the peripheral part of the screw hole (not shown). Has been.

  The bracket 8 functions as a shield member integrated with the frame 7. However, since the bowl-shaped plate 81 of the bracket 8 covers the frame 7 from the glass surface 50 side, the bracket 8 is the frame 7 out of the shield members. As a result, the antenna element 3 is greatly affected as a ground. Further, since the bowl-shaped plate 81 of the bracket 8 is square and the radiation conductor plate 35 protrudes into the square opening 80, the radiation conductor plate 35 and the antenna element 3 are in two orthogonal resonance modes. The relative positional relationship of the bowl-shaped plate 81 can be set almost the same. Therefore, even if the frame 7 has a different shape from the antenna element 3, the deterioration of the axial ratio caused by the shield member can be effectively avoided.

  As described above, the antenna device 1 according to this embodiment is configured such that the antenna elements 3 and 4 are disposed on the circuit board 2 so that the GPS signal can be received and the ETC signal can be transmitted and received. Since the preamplifier for the diversity antenna 20 to be received and the connector terminals 10 of the preamplifier are arranged on the left and right edges of the circuit board 2 to integrate the antenna mechanism, it is multifunctional and simplifies wiring. This is an excellent in-vehicle antenna device that has a good space factor. Further, the antenna device 1 is mounted on a glass surface 50 such as a windshield, and the radiation conductor plates 35 and 41 of the antenna elements 3 and 4 are opposed to the glass surface 50. A good sensitivity can be expected because the GPS signal and the ETC signal can be almost directly opposed to each other. Moreover, as shown in FIGS. 7 and 8, the diversity antennas 20 are disposed on the left and right sides in the vicinity of the antenna device 1 on the glass surface 50, so that the preamplifiers are provided in the vicinity of the diversity antennas 20. Therefore, attenuation of the received terrestrial digital wave signal can be suppressed.

  Further, since the antenna device 1 is arranged such that the radiation conductor plate 41 of the antenna element 4 having a small diameter and a low profile protrudes into the opening 30 of the radiation conductor plate 35 of the antenna element 3, each antenna element 3. , 4 can be arranged on the circuit board 2 in a space-efficient manner and can be easily reduced in size, and complicated processing for ensuring radiation efficiency with respect to the circuit board 2 (partly changing the plate thickness) Etc.) is not necessary. Then, the heights of the antenna elements 3 and 4 on the circuit board 2 are made different to hold the radiating conductor plates 35 and 41 in different planes, and a plurality of pieces are provided along the periphery of the opening 30 of the antenna element 3. Since the antenna element 4 is surrounded by the short-circuit leg piece 39, the electromagnetic isolation between the antenna elements 3 and 4 is increased. Therefore, generation of noise due to interference of radio waves radiated from the radiation conductor plates 35 and 41 is effectively suppressed. Since these antenna elements 3 and 4 are all sheet metal patch antennas, they are easy to manufacture and it is easy to ensure mechanical strength. In addition, since the antenna elements 3 and 4 are two-point feeding type circularly polarized patch antennas, it is easy to increase the bandwidth and improve the axial ratio characteristics.

  However, in this antenna device 1, the frame 7 that is a shield member of the preamplifier for the diversity antenna 20 is different from the antenna element 3 and surrounds the antenna element 3. 3 may adversely affect the axial ratio of 3, so that the diameter D1 corresponding to one power feeding part P1 of the radiation conductor plate 35 of the antenna element 3 is appropriately dimensioned more than the diameter D2 corresponding to the other power feeding part P2. By setting it as short as possible, the axial ratio is corrected by causing a required difference in the resonance length of two resonance modes that are electrically and spatially orthogonal. Further, by arranging the partition plate 73 attached to the frame body 7 between the side plate 72 and the antenna element 3, not only the shielding effect is enhanced, but also the deterioration of the axial ratio caused by the frame body 7 is suppressed. ing.

  Moreover, in this antenna device 1, the bracket 8 fixed to the glass surface 50 functions as a shield member integrated with the frame body 7, and the frame body 7 is covered from the glass surface 50 side by the bowl-shaped plate 81 of the bracket 8. Thus, the ground effect of the frame body 7 with respect to the antenna element 3 is relatively reduced. And since the radiation conductor plate 35 protrudes in the square opening 80 defined in the square bowl-shaped plate 81, the radiation conductor plate 35 and the bowl-shaped plate in two orthogonal resonance modes of the antenna element 3 The relative positional relationship of 81 can be set almost the same, and the deterioration of the axial ratio caused by the shield member is greatly reduced. Therefore, this antenna device 1 can easily ensure good axial ratio characteristics, and there is no need to perform complicated axial ratio correction work such as changing the design of the 90-degree phase difference circuit.

  Further, in the antenna device 1, if the hook-shaped plate 81 of the bracket 8 is fixed to the glass surface 50 in advance, the connecting piece 76 of the frame body 7 is fastened and fixed to the standing piece 82 of the bracket 8 with the fixing screw 9. Only the frame 7 holding the antenna elements 3 and 4 and the circuit board 2 can be firmly fixed to the glass surface 50. At the time of inspection or repair, the frame body 7 can be removed from the glass surface simply by releasing the fastening of the fixing screw 9. Therefore, this antenna device 1 can be easily attached to and detached from the glass surface 50, and it is easy to secure the mounting strength. In addition, the upright piece 82 of the bracket 8 is fastened and fixed to the connecting piece 76 in a state where the nut portion 82a is inserted into the cutout 74 of the side plate 72 of the frame body 7. Therefore, the upright piece 82 is accurately fixed by the cutout 74. Therefore, the alignment of the frame body 7 and the bracket 8 can be performed very easily.

  In this antenna device 1, the left and right edges of the circuit board 2 are formed by engaging the connecting piece 76 and the locking piece 78 on one side of the circuit board 2 and engaging the bent tongue 77 on the other side. Since the simple support structure of sandwiching the portion in the plate thickness direction is employed, the frame body 7 can hold the circuit board 2 easily and reliably. In addition, since the receiving portion 76b of the connecting piece 76 supports the circuit board 2 in the vicinity of the connector terminal 10 from the back side, the circuit board 2 is connected when the signal cable 21 of the diversity antenna 20 is connected to the connector terminal 10 by a connector. Is pushed, the circuit board 2 supported by the connecting piece 76 from the back side does not bend, so that damage to the circuit board 2 and the mounted components can be avoided and reliability is improved.

  Further, in this antenna device 1, the preamplifier of the diversity antenna 20 is covered with the frame 7 and the bracket 8 and electromagnetically shielded, so that no noise is generated in the antenna elements 3 and 4 by the preamplifier. However, the frame 7 also has a function of guiding the signal cable 21 of the diversity antenna 20 to the connector terminal 10. That is, since the signal cable 21 is guided to the connector terminal 10 via the cutout groove 75 and the bent tongue piece 77 of the frame body 7, the signal cable 21 can be smoothly passed without being damaged. The connector terminal 10 can be connected to the connector.

  Note that the present invention is directed to an in-vehicle antenna device which is provided with a preamplifier for an external antenna to achieve multi-functions, and the structure and number of antenna elements mounted on the circuit board 2 are specified in the above embodiment. It can be changed as appropriate.

1 is an exploded perspective view of an antenna device according to an embodiment of the present invention. It is a front view of the antenna device. It is a perspective view of the back side which shows the state which removed this antenna device from the bracket. FIG. 4 is a front perspective view corresponding to FIG. 3. It is a perspective view of the back side which shows the state which connected the signal cable of the diversity antenna to this antenna apparatus with a connector. FIG. 6 is an explanatory diagram in which the signal cable and the bracket are omitted from FIG. 5 and the cable insertion portion is clearly shown. It is a rear view which shows arrangement | positioning of this antenna device and this diversity antenna whole. FIG. 8 is a front view corresponding to FIG. 7.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Antenna apparatus 2 Circuit board 3, 4 Antenna element 5 Shield cover 7 Frame 8 Bracket 9 Fixing screw 10 Connector terminal 20 Diversity antenna 21 Signal cable 35 Radiation conductor plate 36, 37 Feeding leg piece 38 Mounting leg piece 39 Short-circuit leg Piece 41 Radiation conductor plate 43, 44 Feeding leg piece 45 Mounting leg piece 50 Glass surface 71, 72 Side plate 75 Notch groove 76 Connecting piece 77 Bending tongue piece 78 Locking piece 81 Hook-shaped plate 82 Standing piece

Claims (4)

A circuit board on which an antenna element is mounted, a frame made of a metal plate having a side plate extending along the edge of the circuit board and holding the circuit board, and disposed in the vicinity of the edge of the circuit board A preamplifier for the external antenna and a connector terminal of the preamplifier,
The frame body is formed as a cut-and-raised piece extending obliquely inwardly from the side plate, and a bent tongue piece engageable with one surface of the circuit board in the vicinity of the connector terminal, and the bent tongue A notch groove including a space generated in the side plate by cutting and raising the piece is provided, and the signal cable of the external antenna inserted into the notch groove is guided by the bent tongue piece to the connector terminal. An in-vehicle antenna device characterized by being guided.   2. The pair of edges according to claim 1, wherein the external antenna is a pair of diversity antennas, and the pair of connector terminals for connecting signal cables of the diversity antennas extend substantially parallel to the circuit board. And the bent tongue pieces extend inward from the pair of side plates extending along the pair of edges, respectively.   3. The vehicle-mounted antenna according to claim 1, wherein an engagement piece that extends inward from the side plate and engages with the other surface of the circuit board is provided on the frame body. apparatus.   The vehicle-mounted antenna device according to claim 1, wherein a partition plate disposed between the side plate and the antenna element is provided on the frame body.

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