JP2018207296A - On-vehicle radio receiving device - Google Patents

Abstract

To provide an on-vehicle radio receiving device in novel structure capable of attaining further antenna space efficiency improvement or further structure simplification.SOLUTION: In an on-vehicle radio receiving device 10 configured by including a printed circuit board 18 in which a radio receiving circuit 16 is provided and an antenna part 24 connected to the radio receiving circuit 16, the antenna part 24 is a monopole antenna in which a sheet metal antenna 28 that is formed by bending a band-plate-like sheet metal and mounted while being placed on the printed circuit board 18 and a pattern antenna 30 that is formed from print wiring of the printed circuit board 18 are connected in one-side ends 60 and 62 thereof, and one end 64 of other-side ends thereof is connected to the radio receiving circuit 16. In a planar view of the printed circuit board 18, the pattern antenna 30 is provided within a region 66 that is enclosed by the sheet metal antenna 28.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an in-vehicle wireless reception device that is mounted on an automobile and has a wireless reception function used in various wireless communication systems for automobiles.

  Conventionally, a wireless communication system such as a remote keyless entry system or a tire pressure monitoring system has been adopted for an automobile, and an in-vehicle wireless receiver as an apparatus mounted on the automobile for receiving a wireless signal in each system. It has been known. For example, as described in Japanese Patent Application Laid-Open No. 2007-68115 (Patent Document 1), this in-vehicle wireless reception device includes a printed circuit board having a wireless reception circuit and a metal wire antenna to which the wireless reception circuit is connected. I have.

  By the way, due to the recent increase in in-vehicle products and the downsizing of vehicles, it is required to configure the in-vehicle wireless receiver more space-saving. Therefore, in Patent Document 1, a metal wire antenna is connected to a wireless reception circuit of a printed circuit board via a power feeding pattern, while a pattern antenna provided on the printed circuit board is connected to a connection position between the metal wire antenna and the power feeding pattern, It has been proposed to construct a dipole antenna. As a result, the antenna length of the half wavelength (λ / 2) of the frequency required for the dipole antenna can be distributed to the metal wire antenna and the pattern antenna so that each antenna length can be λ / 4. Each of the line antenna and the pattern antenna can be reduced in size. However, the metal wire antenna and the pattern antenna need to be provided in different areas of the printed circuit board, and there is a problem that the space efficiency is poor.

  Japanese Patent Laying-Open No. 2016-32246 (Patent Document 2) discloses a pattern antenna provided on the entire circumference of a printed circuit board, an empty terminal of a connector provided on a side edge of the printed circuit board, and an antenna embedded in a housing. An in-vehicle wireless receiver in which lines are connected to each other to form a loop antenna has been proposed. In this structure, miniaturization is realized by securing an antenna installation space using a connector provided on a printed circuit board. However, there is still room for improvement in terms of space efficiency and cost because it is necessary to provide a pattern antenna on almost the entire circumference of the printed circuit board and a specific connector with an antenna wire embedded in the connector. was there.

JP 2007-68115 A Japanese Unexamined Patent Publication No. 2016-32246

  The present invention has been made in the background of the above-mentioned circumstances, and the problem to be solved is a vehicle-mounted radio reception with a novel structure that can further improve the space efficiency of the antenna and further simplify the structure. To provide an apparatus.

  According to a first aspect of the present invention, there is provided a vehicle-mounted wireless reception device including a printed circuit board provided with a wireless reception circuit and an antenna unit connected to the wireless reception circuit. A sheet metal antenna formed by bending a sheet metal plate mounted and mounted on the printed circuit board and a pattern antenna formed by printed wiring of the printed circuit board are connected at one end thereof, One of the other end portions is a monopole antenna configured by being connected to the wireless receiving circuit, and the pattern antenna is surrounded by the sheet metal antenna in a plan view of the printed circuit board. It is provided in the inside.

  According to this aspect, the antenna unit of the wireless reception device is configured as a grounded monopole antenna, and the monopole antenna is configured by connecting the sheet metal antenna and the pattern antenna at their one ends. ing. Therefore, since the antenna length can be set to about λ / 4 with respect to the wavelength λ of the transmission / reception wave, and the monopole antenna is configured by connecting the two components of the sheet metal antenna and the pattern antenna, The length of each of the antenna and the pattern antenna can be further shortened. Thereby, size reduction of an antenna part can be achieved advantageously. In addition, since the pattern antenna is provided in a region surrounded by the bent sheet metal antenna in a plan view of the printed circuit board, the antenna portion is compared with a dipole antenna or a loop antenna having a conventional structure. As a result, it is possible to more effectively meet the demand for downsizing of the wireless receiver.

  In addition, a sheet metal antenna is formed by bending a band-shaped sheet metal and mounting it on a printed circuit board, and the antenna unit can be configured simply by mounting and mounting so as to surround the pattern antenna. Therefore, the structure can be simplified and the cost can be reduced as compared with the case where a special connector with a metal wire embedded therein is required as in the conventional structure.

  According to a second aspect of the present invention, in the above-described first aspect, the sheet metal antenna includes a main body portion whose longitudinal middle portion is bent in a U-shape, and one end portion of the main body portion. Including a circuit connection protrusion provided to protrude toward the printed circuit board, and a pattern antenna connection protrusion provided to protrude from the other end of the main body toward the printed circuit board. The projection for connecting the circuit of the sheet metal antenna is connected to the wireless reception circuit as the other end of the sheet metal antenna, while the projection for connecting the pattern antenna of the sheet metal antenna is connected to the sheet metal antenna. The one end is connected to the one end of the pattern antenna.

  According to this aspect, since the sheet metal antenna includes the main body portion whose middle portion in the longitudinal direction is bent in a U-shape, the shape of the entire sheet metal antenna can be maintained compact while increasing the antenna length.

  In addition, the circuit connection protrusion (other end) of the sheet metal antenna is first connected to the wireless reception circuit, and the pattern antenna is connected to the pattern antenna connection protrusion (one end) of the sheet metal antenna away from the wireless reception circuit. The pattern antenna is extended from the connection. As a result, compared to the case where the sheet metal antenna is connected to the radio receiving circuit via the pattern antenna, the sheet metal antenna is formed by the internal resistance of the pattern antenna having a resistance that cannot be ignored because it is composed of a thin copper foil pattern. It is advantageously avoided that the receiving sensitivity of the receiver is reduced.

  A third aspect of the present invention is the one described in the first aspect, wherein the pattern antenna is a meander type antenna.

  According to this aspect, since the pattern antenna is a meander type antenna, a sufficient antenna length can be ensured even when the surrounding area of the sheet metal antenna in a plan view on the printed circuit board is small, The antenna unit can be configured with even more space efficiency.

  According to the present invention, the antenna unit of the radio receiving apparatus is configured as a grounded monopole antenna by connecting a sheet metal antenna and a pattern antenna at one end thereof. Therefore, since the antenna length can be set to about λ / 4 with respect to the wavelength λ of the transmission / reception wave, and the monopole antenna is configured by connecting the two components of the sheet metal antenna and the pattern antenna, The length of the antenna and the pattern antenna can be further shortened, and the antenna portion can be advantageously downsized. In addition, in the plan view of the printed circuit board, since the pattern antenna is provided in the region surrounded by the bent sheet metal antenna, the formation region of the antenna portion can be more efficiently secured, It is possible to respond more advantageously to the demand for miniaturization of the wireless receiver. In addition, the sheet metal antenna is formed by bending a band-shaped sheet metal plate and placing it on a printed circuit board, and since the antenna unit can be configured simply by placing and mounting so as to surround the pattern antenna, Compared to the case where a special connector having a metal wire embedded therein is required as in the conventional structure, the structure can be simplified and the cost can be reduced.

The disassembled perspective view which shows the vehicle-mounted radio | wireless receiver as one Embodiment of this invention. The disassembled perspective view of the printed circuit board shown in FIG. The top view of the printed circuit board shown in FIG.

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

  1-3, the vehicle-mounted radio | wireless receiver 10 as one Embodiment of this invention is shown. As shown in FIG. 1, an in-vehicle wireless receiver 10 includes an upper case 12 formed by injection molding or the like using a synthetic resin such as polyamide (PA), polycarbonate (PC), or polyphthalamide (PPA). The printed circuit board 18 on which a wireless IC (Integrated Circuit) 16 that is a wireless reception circuit is mounted is accommodated between the lower case 14 and the lower case 14. In the following description, unless otherwise specified, the upper direction is the upper side in FIG. 1, the lower side is the lower side in FIG. 1, the front is the left side in FIG. 3, and the rear is the FIG. Say right inside.

  As shown in FIG. 1, the upper case 12 and the lower case 14 have a substantially rectangular shallow box shape opening toward each other. The upper case 12 and the lower case 14 are engaged by, for example, engaging hooks (not shown) provided in the upper case 12 being inserted through engagement frames (not shown) provided in corresponding portions of the lower case 14. As a result, they can be assembled together. In addition, a bracket mounting portion (not shown) is provided at an appropriate place spaced in the circumferential direction on the peripheral wall of the upper case 12 or the lower case 14, and a bracket (not shown) provided on the vehicle body side is attached to the in-vehicle wireless receiver. 10 is mounted and fixed at an appropriate position of the vehicle.

  On the other hand, as shown in FIGS. 1 to 3, the printed circuit board 18 has a substantially rectangular flat plate shape made of a known insulating material such as a glass epoxy resin. A wireless IC 16 which is a wireless receiving circuit is mounted at a substantially central portion on the right side in FIG. The wireless IC 16 is connected to one end side of a power feeding pattern 20 configured by printed wiring, and is connected to the other end side of the power feeding pattern 20 via a through hole 22. The through hole 22 is formed so as to penetrate the printed circuit board 18 with a substantially circular cross-sectional shape, and a plating layer (not shown) is formed on the entire inner peripheral surface of the through hole 22. A flange-shaped land portion 26 is provided around the opening. Then, the power supply pattern 20 is connected to the land portion 26 on the other end side, so that a plating layer (not shown) applied to the inner peripheral surface of the through hole 22 and the power supply pattern 20 are connected to each other. .

  As shown in FIGS. 1 to 3, the antenna unit 24 is formed, for example, by stamping and bending a sheet metal that is a metal plate having a surface such as a copper plate plated with tin or the like. A sheet metal antenna 28 and a pattern antenna 30 formed by printed wiring of the printed circuit board 18 are provided. The sheet metal antenna 28 includes a main body portion 32 in which a longitudinally intermediate portion is bent in a U-shape in a state in which a strip-shaped sheet metal is placed vertically, that is, the plate thickness direction is a horizontal direction, and one end portion 34 of the main body portion 32. The circuit connection projection 36 having a substantially rectangular flat plate shape as viewed from the side and projecting toward the printed circuit board 18, and the side surface projecting from the other end 38 of the main body 32 toward the print circuit board 18. And a pattern antenna connecting projection 40 having a substantially rectangular flat plate shape as viewed.

  The main body 32 connects a pair of parallel extending portions 42 and 42 extending in parallel in the longitudinal direction (left and right direction in FIG. 3) with a gap therebetween, and one end side (left end side in FIG. 3) thereof. And extending vertically. In addition, one end side (left end side in FIG. 3) of the parallel extending portion 42 is provided with a supporting leg portion 46 that protrudes toward the printed circuit board 18 and has a substantially rectangular flat plate shape in side view. As shown in FIG. 2, the circuit connection protrusion 36 and the pattern antenna connection protrusion 40 have substantially the same shape, and the width direction of the protrusion tip (left and right direction in FIGS. 1 to 3). A substantially rod-shaped lead portion 48 is provided at the center portion of the protruding portion so as to protrude toward the printed circuit board 18, and at both end portions in the width direction (left and right directions in FIGS. 1 to 3) of the protruding tip portion in side view. A substantially triangular flat plate-shaped stopper 50 is provided so as to protrude toward the printed circuit board 18. Further, as shown in FIG. 2, the support legs 46 have substantially the same shape, and are substantially rod-shaped at both ends in the width direction (left and right directions in FIGS. 1 to 3) of the protruding tip. The press-fitting protrusion 52 is provided so as to protrude toward the printed circuit board 18 and has a substantially rectangular flat plate-like stopper in a side view in the center of the protruding tip in the width direction (left and right in FIGS. 1 to 3). A portion 54 is provided to protrude toward the printed circuit board 18. As shown in FIG. 3, in this embodiment, the length dimension L1 of the vertical extension 44 is from the circuit connection projection 36 of the parallel extension 42 to the vertical extension 44. Length dimension: about 1/5 of L2.

  On the other hand, as shown in FIGS. 1 to 3, the pattern antenna 30 is a meander type antenna. That is, since the pattern antenna 30 is configured by a shape in which printed wiring is meandered in a zigzag shape, the area constituting the pattern antenna 30 can be reduced. Note that one end (right end in FIG. 3) of the pattern antenna 30 is connected to a through hole 22 provided in the printed circuit board 18.

  1-2, the sheet metal antenna 28 is placed on the printed circuit board 18 from above the printed circuit board 18 with the main body 32 of the sheet metal antenna 28 facing upward, and soldering is performed. By doing so, the sheet metal antenna 28 is mounted on the printed circuit board 18. More specifically, first, the circuit connection projection 36 of the sheet metal antenna 28 and the lead portion 48 of the pattern antenna connection projection 40 are respectively inserted into the through holes 22 and the press-fitting projections of the support legs 46. 52 is press-fitted into a press-fitting hole 56 having a substantially circular cross-sectional shape penetrating on the printed board 18. In this state, the protrusions 36 of the circuit connection protrusion 36 and the pattern antenna connection protrusion 40 and the protruding tips of the contact stopper 54 of the support leg 46 abut on the surface 58 of the printed circuit board 18. This advantageously prevents the lead portion 48 and the press-fit protrusion 52 from entering the through hole 22 and the press-fit hole 56 of the printed circuit board 18 more than necessary. Subsequently, a soldering step is performed, and a plating layer (not shown) applied to the inner peripheral surface of the projecting part 36 for circuit connection, the lead part 48 of the projecting part 40 for pattern antenna connection, and the through hole 22 is passed through solder (not shown). By conducting the conductive connection, the projection 40 for connecting the pattern antenna of the sheet metal antenna 28 is connected to the one end 62 of the pattern antenna 30 as one end 60 of the sheet metal antenna 28, and the circuit of the sheet metal antenna 28. The connecting protrusion 36 is connected to the wireless IC 16 that is a wireless receiving circuit via the power feeding pattern 20 as the other end 64 of the sheet metal antenna 28. That is, the sheet metal antenna 28 and the pattern antenna 30 are connected to each other at their one end portions 60 and 62, and the other end portion 64 of the sheet metal antenna 28, which is one of the other end portions, is connected to the feeding pattern. 20 is connected to a wireless IC 16 which is a wireless receiving circuit. Of the antenna unit 24 configured to include the sheet metal antenna 28 and the pattern antenna 30, a ground pattern (not shown) for forming a grounded monopole antenna is provided on the printed circuit board 18. In the present embodiment, as shown in FIG. 3, the pattern antenna 30 is provided in a region 66 surrounded by the sheet metal antenna 28 in a plan view of the printed circuit board 18.

  As shown in FIG. 1, the in-vehicle wireless receiver 10 of the present invention is completed by accommodating and arranging the printed circuit board 18 having such a configuration between the upper case 12 and the lower case 14. It has become. More specifically, first, the printed circuit board 18 of the present embodiment is accommodated in the lower case 14 that opens upward. The printed circuit board 18 is fixed to the lower case 14 by fixing means (not shown) such as screwing if necessary. Subsequently, the opening of the lower case 14 is covered with the upper case 12, and the upper case 12 and the lower case 14 are assembled to each other by engagement means (not shown), whereby the in-vehicle wireless reception device 10 of the present invention is completed. is there. Since the signal wirelessly transmitted from the portable device often reaches the in-vehicle wireless reception device 10 after being reflected a plurality of times in the passenger compartment, the signal is transmitted from various directions to the antenna unit 24 of the printed circuit board 18. To reach. In the present embodiment, the pattern antenna 30 constituting the antenna unit 24 increases the reception sensitivity of the horizontally polarized signal in which the polarization plane of the signal is parallel to the surface 58 of the printed circuit board 18, while the antenna unit 24 is configured. The reception sensitivity of the vertically polarized signal in which the plane of polarization of the signal is perpendicular to the surface 58 of the printed circuit board 18 is increased by the sheet metal antenna 28 to be able to cope with signals arriving from various directions. Yes.

  According to the in-vehicle wireless receiver 10 of the present embodiment having such a structure, since the antenna unit 24 is configured as a grounded monopole antenna, the entire length of the antenna unit 24 is set to the wavelength λ of the transmission / reception wave. Can be set to about λ / 4. Moreover, since the antenna unit 24 has a configuration in which the sheet metal antenna 28 and the pattern antenna 30 are connected in series, the length of each of the sheet metal antenna 28 and the pattern antenna 30 can be further shortened. 24 can be advantageously reduced in size. In addition, since the pattern antenna 30 is provided in the region 66 surrounded by the sheet metal antenna 28 in a plan view of the printed circuit board 18, the formation region of the antenna portion 24 can be more efficiently secured, and the in-vehicle wireless It is possible to more advantageously meet the demand for downsizing of the receiving device 10. Furthermore, the use of the sheet metal antenna 28 eliminates the need for a special connector in which a metal wire is embedded as in the prior art, so that the cost can be reduced. Further, the length dimension L1 of the vertical extension 44 is approximately 1/5 of the length dimension L2 from the circuit connection protrusion 36 of the parallel extension 42 to the vertical extension 44. The region 66 surrounded by the sheet metal antenna 28 is a flat rectangular region, and can be easily disposed in a gap space of the printed circuit board 18 or the like.

  In addition, since the sheet metal antenna 28 includes the main body portion 32 whose longitudinal middle portion is bent in a U shape, the overall area of the antenna portion 24 is increased, and the configuration area of the sheet metal antenna 28 is made compact. Can do. Moreover, in the present embodiment, since the pattern antenna 30 is connected to the wireless IC 16 that is a wireless reception circuit via the sheet metal antenna 28, the pattern antenna 30 is compared with the case where the sheet metal antenna 28 is connected via the pattern antenna 30. Thus, it is advantageously avoided that the reception sensitivity of the sheet metal antenna 28 is lowered by the internal resistance of the pattern antenna 30 having a resistance that cannot be ignored because it is composed of a thin copper foil pattern.

  Further, since the pattern antenna 30 is a meander type antenna, a sufficient antenna length can be secured even when the area allowed for the pattern antenna 30 on the printed circuit board 18 is small. ing.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited at all by the specific description in this embodiment. For example, in the above-described embodiment, the sheet metal antenna 28 is configured to include the main body portion 32 bent in a U-shape. However, the main body portion 32 has an arbitrary shape such as an L shape, a square shape, or a straight shape. Can be adopted. In the above embodiment, the pattern antenna 30 is a meander type antenna. However, a pattern antenna having an arbitrary shape such as a loop shape may be employed. In addition, in the present embodiment, the configuration in which the pattern antenna 30 is connected to the wireless IC 16 that is a wireless reception circuit via the sheet metal antenna 28 has been described as an example. The case where the sheet metal antenna 28 is connected is also included in the present invention.

DESCRIPTION OF SYMBOLS 10: Radio | wireless receiver for vehicle mounting, 16: IC for radio | wireless (radio receiver circuit), 18: Printed circuit board, 24: Antenna part, 28: Sheet metal antenna, 30: Pattern antenna, 32: Main part, 34: One edge part 36: projection for circuit connection, 38: other end, 40: projection for pattern antenna connection, 60: one end, 62: one end, 64: other end, 66: region

Claims (3)

A printed circuit board provided with a wireless receiving circuit;
In the in-vehicle wireless reception device configured to include an antenna unit connected to the wireless reception circuit,
The antenna portion is formed by bending a strip-shaped sheet metal, and is mounted on the printed board and mounted thereon, and a pattern antenna formed by the printed wiring of the printed board has one end thereof It is a monopole antenna configured by being connected to each other and one of the other end portions being connected to the wireless reception circuit,
The in-vehicle wireless receiver characterized in that the pattern antenna is provided in a region surrounded by the sheet metal antenna in a plan view of the printed circuit board. The sheet metal antenna includes a main body portion whose middle portion in the longitudinal direction is bent in a U-shape, a circuit connection protrusion provided to project from one end of the main body portion toward the printed circuit board, and the main body. A pattern antenna connection protrusion provided to protrude from the other end of the portion toward the printed circuit board,
The projection for connecting the circuit of the sheet metal antenna is connected to the wireless reception circuit as the other end of the sheet metal antenna, while the projection for connecting the pattern antenna of the sheet metal antenna is connected to the sheet metal antenna. The in-vehicle wireless receiver according to claim 1, wherein the one end is connected to the one end of the pattern antenna.   The in-vehicle wireless receiver according to claim 1, wherein the pattern antenna is a meander type antenna.

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