JP4461069B2 - Compound antenna device - Google Patents

Description

  The present invention relates to a composite antenna device, and more particularly to a composite antenna device equipped with a GPS (global positioning system) antenna and a wireless LAN (local area network) antenna.

  As is well known in the art, various antennas are currently mounted on vehicles. For example, one such antenna is a GPS (Global Positioning System) antenna.

  GPS (Global Positioning System) is a satellite positioning system using artificial satellites. The GPS receives radio waves (GPS signals) from four of the 24 artificial satellites orbiting the earth, and the positional relationship and time error between the moving body and the artificial satellites from the received radio waves. Based on the principle of triangulation, it is possible to calculate the position and altitude of the moving body on the map with high accuracy.

  In recent years, GPS has been widely used in car navigation systems that detect the position of a traveling vehicle. The car navigation device includes a GPS antenna for receiving the GPS signal, a processing device for processing the GPS signal received by the GPS antenna to detect the current position of the vehicle, and a position detected by the processing device. Is displayed on a map.

  The GPS antenna is installed outside the vehicle such as on the roof of an automobile in order to efficiently receive GPS signals (see, for example, Patent Document 1).

  This car navigation device includes a storage device that stores a travel history (route) of a traveling vehicle.

  A LAN (local area network) is a network that connects a plurality of independent devices to each other, and is closed in a limited area that is under the jurisdiction of a user, such as a single building or premises. In other words, a LAN is not based on a public communication line, and has a transmission path length of about several in a network in which a transmission path is independently laid out according to the purpose and various devices such as computers and terminals are interconnected. Small to medium sized from 10 meters to several tens of kilometers. Among such LANs, a wireless LAN is a system in which a LAN cable such as a coaxial cable or a twin-pair cable is made wireless, and can be accessed from a place without LAN wiring. In order to construct a wireless LAN, a wireless LAN antenna is required.

  By mounting such a wireless LAN antenna on a vehicle, it is possible to transmit data indicating a travel history (route) stored in the storage device of the car navigation device to a personal computer. For example, by attaching this wireless LAN antenna to a taxi or the like equipped with a car navigation device, the route on which the taxi actually traveled can be managed.

  In general, a GPS antenna and a wireless LAN antenna are separately mounted on a vehicle. Considering vehicle mounting efficiency, it is desirable to integrate these two antennas.

  On the other hand, a composite antenna in which a GPS antenna and a communication antenna are integrated is known (see, for example, Patent Document 2). In this Patent Document 2, a GPS plate antenna and a metal pedestal into which a rod-like whip antenna is inserted are provided in an antenna case molded using an insulating material to prevent rainwater from entering.

  Conventionally, various composite antenna devices are also known. For example, a highly reliable composite antenna that is suitable for miniaturization and thinning by combining a circularly polarized antenna and a vertically polarized antenna is known (see, for example, Patent Document 3). The composite antenna disclosed in Patent Document 2 is a composite antenna that is mounted on a moving body such as an automobile and can receive satellite waves (circularly polarized waves) and terrestrial waves (vertically polarized waves). This composite antenna disclosed in Patent Document 3 uses a through hole provided in the center of a patch antenna that is a circularly polarized antenna for satellite waves to establish a helical antenna that is a vertically polarized antenna for terrestrial waves. Has been established.

  A composite antenna is known that is a combination of a circularly polarized antenna used for communication between a geostationary satellite and a mobile object and a monopole antenna for ground wave (see, for example, Patent Document 4). The composite antenna disclosed in Patent Document 4 includes a circularly polarized antenna in which a radiation conductor inclined at a predetermined angle is provided on each side surface of a quadrangular prism-shaped dielectric, and an inclined portion on the tip side from the standing portion. The monopole antenna is attached on the printed circuit board.

  A composite antenna device suitable for a wireless LAN system built in a home is also known (see, for example, Patent Document 5). The composite antenna device disclosed in Patent Document 5 includes first and second antennas and a cable connecting the antennas, and the first antenna and the second antenna sandwich a door. The entire device is attached to the door so that it is located on both sides. A signal received by the first antenna is transmitted from the second antenna, and / or a signal received by the second antenna is transmitted from the first antenna.

JP 2005-10987 A Japanese Utility Model Publication No. 5-76106 JP 2004-48369 A Japanese Patent Laid-Open No. 2003-110355 JP 2003-264410 A

  In the composite antenna disclosed in Patent Document 2, the length of the rod-like whip antenna is a value close to a quarter wavelength of the wavelength of the radio wave used for transmission and reception, so that the overall height of the device is increased. There's a problem. On the other hand, the composite antennas disclosed in Patent Document 3 and Patent Document 4 are antennas for receiving satellite waves that are circularly polarized waves and terrestrial waves that are linearly polarized waves, and are antennas for GPS and wireless LANs. Like an antenna, it is completely different from those equipped with a plurality of types of antennas with different applications. Further, the composite antenna device disclosed in Patent Document 5 is used in a wireless LAN system, and includes a plurality of types of antennas having different uses such as a GPS antenna and a wireless LAN antenna. Is completely different.

  Accordingly, an object of the present invention is to provide a low-profile composite antenna device capable of mounting a plurality of types of antennas having different uses on a circuit board.

According to the onset bright, and the substrate (11) with the exception of grounded main surface (11a) a predetermined region (32), the predetermined and area which is formed on the feeding electrode (60), the main surface of the substrate ( A planar antenna element (21) mounted on 11a), an electronic circuit connected to the planar antenna element and mounted on the back surface (11b) of the substrate, and the planar antenna on the main surface (11a) A pole antenna element (30) having a coil portion (31) that is erected from the feeding electrode (60) spaced apart from the element (21) and wound in a coil shape, and the feeding electrode (60) A composite antenna device (10) is obtained which is for impedance adjustment and is surrounded by a non-ground region .

  In the composite antenna device according to the present invention, the planar antenna element (21) may be constituted by a patch antenna. The planar antenna element (21) may be a GPS antenna, and the pole antenna element (30) may be a wireless LAN antenna.

Further, the composite antenna apparatus according to the present invention, the planar antenna element (21), based on the above main surface may be a shall be set to the receiving unit at a predetermined distance spaced positions in the height direction the pole antenna element (30) may be one which signals received at positions spaced in the height direction than the reception section of the planar antenna element.

  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 of course is not limited to these.

  In the present invention, since the pole antenna element has a coil portion wound in a coil shape, the height of the composite antenna device can be reduced.

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

  A composite antenna apparatus 30 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view of the composite antenna device 10, and FIG. 2 is a plan view of the composite antenna device 10, with an antenna case described later omitted.

  The illustrated composite antenna device 10 includes a circuit board 11 having a main surface 11a and a back surface (described later) facing each other. As shown in FIGS. 1 and 2, the circuit board 11 has a substantially rectangular shape with chamfered corners. Therefore, actually, the circuit board 11 has a substantially octagonal shape.

  A planar antenna element 21 is mounted on one end 111 side on the main surface 11 a of the circuit board 11. An LNA (low noise amplification) circuit (not shown) is mounted on the back surface of the circuit board 11. This LNA circuit is connected to the planar antenna element 21. As shown in FIGS. 1 and 2, the planar antenna element 21 is configured by a patch antenna. The planar antenna element 21 is a GPS antenna.

  A signal output from the LNA circuit is transmitted to a processing device (not shown) of the car navigation device via the first coaxial cable 41 drawn from the other end 112 of the circuit board 11.

  A pole antenna element 30 is erected at a position away from the planar antenna element 21 on the main surface 11 a of the circuit board 11. That is, the pole antenna element 30 is provided on the other end 112 side on the main surface 11 a of the circuit board 11. The pole antenna element 30 has a coil portion 31 wound in a coil shape. The pole antenna element 30 is a wireless LAN antenna. An installation base (predetermined area) 32 is provided at the lower end of the pole antenna element 30. A substantially rectangular impedance adjusting power supply electrode 60 is formed in the installation base 32. By soldering the pole antenna element 30 to the power supply base 32, power is supplied to the pole antenna element 30 and the main surface 11a. Fixed on top.

  As described above, the pole antenna element 30 is used as the wireless LAN antenna because the antenna directivity required for the wireless LAN antenna is vertical polarization in the horizontal direction and the GPS antenna (planar antenna element) as much as possible. This is to avoid the shadow of 21.

  The pole antenna element 30 is connected to the processing apparatus via a second coaxial cable 42 provided together with the first coaxial cable 41.

  Next, the dimensions of the composite antenna device 10 in the illustrated example will be described. The dimension W in the longitudinal direction of the circuit board 11 is 50 mm, and the dimension D in the lateral direction is 43 mm. The planar antenna element 21 has a vertical dimension W1 and a horizontal dimension D1 of 20 mm and 20 mm, respectively, and a height dimension H1 of 4 mm. The illustrated pole antenna element 30 has a height dimension H2 of 18 mm, and the coil part 31 has a height dimension H3 of 7 mm. A distance W2 between the center of the planar antenna element 21 and the center of the pole antenna element 30 is 22.5 mm. A distance W3 between the center of the pole antenna element 30 and the planar antenna element 21 on the side close to the pole antenna element 30 is 12.5 mm. The vertical dimension W4 and the horizontal dimension D2 of the installation base 32 on which the pole antenna element 30 is installed are 9 mm and 9 mm, respectively.

  The composite antenna device 10 will be described in more detail with reference to FIG. The composite antenna device 10 includes an antenna case to be described later, an antenna module to be described later, a packing member 15, and first and second coaxial cables 41 and 42. The antenna case is configured by joining a dome-shaped top cover 12 and a bottom plate 13. The antenna module is housed in the top cover 12. The packing member 15 is disposed at a joint portion between the top cover 12 and the bottom plate 13 to ensure adhesion of the antenna case. The first and second coaxial cables 41 and 42 are connected to the antenna module.

  The antenna module includes a planar antenna element 21, a pole antenna element 30, and a circuit board 11. The planar antenna element 21 is configured by a patch antenna that receives a GPS signal transmitted from a GPS satellite. An LNA circuit (not shown) that performs signal amplification on the GPS signal received by the planar antenna element 21 is formed on the back surface 11 b of the circuit board 11. The planar antenna element 21 and the main surface 11a of the circuit board 11 are joined by a double-sided tape 16 or the like.

  Connected to the back surface 11b of the circuit board 11 are first and second coaxial cables 41 and 42 for taking out GPS signals to the outside of the antenna case. A shield case 17 for shielding the LNA circuit is attached to the back surface 11b of the circuit board 11. The first and second coaxial cables 41 and 42 are drawn out through a notch 12 a formed in the top cover 12. A gasket 18 is attached at a position corresponding to the notch 12a.

  The composite antenna device 10 is joined and integrated by screwing the top cover 12 and the bottom plate 13 with four screws 50 in a state where the antenna module and the packing member 15 are housed in the internal space of the top cover 12. It becomes.

  A recess 13 a is formed in the bottom plate 13. A pair of permanent magnets 61 and 62 are disposed in these recesses 13a. These permanent magnets 61 and 62 are disposed for attracting and fixing the composite antenna device 10 to the roof of the automobile.

  Thus, since the composite antenna device 10 is installed on the roof of the automobile, the roof can be used as the ground of the composite antenna device 10. As a result, the operation performance as the composite antenna device 10 can be sufficiently secured.

  4 to 6 show antenna radiation patterns of the pole antenna element (wireless LAN antenna) 30 used in the composite antenna device 10. The measurement frequency is 2.44175 GHz, and the size of the ground plate is 1 m in diameter.

  4 shows an XY plane radiation pattern of the wireless LAN antenna 30, FIG. 5 shows an XZ plane radiation pattern of the wireless LAN antenna 30, and FIG. 6 shows a YZ plane radiation of the wireless LAN antenna 30. Indicates a pattern. FIG. 4 shows that the gain is in the range of approximately 0 to −5 dB in almost all angle ranges in the horizontal plane.

  As described above, since the pole antenna element 30 includes the coil portion 31 wound in a coil shape, the height of the pole antenna element 30 can be reduced, and therefore, the composite antenna device 10 can be reduced in height. It becomes.

  Although the present invention has been described above with reference to preferred embodiments, it is needless to say that the present invention is not limited to the above-described embodiments.

It is a perspective view which shows the composite antenna apparatus which concerns on one embodiment of this invention. It is a top view of the composite antenna apparatus shown in FIG. It is a schematic exploded view of the composite antenna apparatus shown in FIG. It is a figure which shows the XY plane radiation pattern of the pole antenna element used for the compound antenna apparatus shown in FIG. It is a figure which shows the XZ plane radiation pattern of the pole antenna element used for the compound antenna apparatus shown in FIG. It is a figure which shows the YZ plane radiation pattern of the pole antenna element used for the compound antenna apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Composite antenna apparatus 11 Circuit board 11a Main surface 11b Back surface 21 Planar antenna element (GPS antenna)
30 Pole antenna element (antenna for wireless LAN)
31 Coil part 32 Installation stand (predetermined area)
41 First coaxial cable 42 Second coaxial cable 60 Feeding electrode

Claims (4)

A substrate having a grounded main surface except for a predetermined area;
A feeding electrode formed in the predetermined region;
A planar antenna element mounted on the main surface of the substrate;
An electronic circuit connected to the planar antenna element and mounted on the back surface of the substrate;
A pole antenna element that has a coil portion that is erected from the feeding electrode spaced apart from the planar antenna element on the main surface and wound in a coil shape ;
The power feeding electrode is for impedance adjustment, and its periphery is surrounded by a non-ground region .   The composite antenna device according to claim 1, wherein the planar antenna element is configured by a patch antenna.   The composite antenna device according to claim 1, wherein the planar antenna element is a GPS antenna, and the pole antenna element is a wireless LAN antenna. The planar antenna element has a receiving portion set at a position spaced apart by a predetermined distance in the height direction with respect to the main surface, and the pole antenna element is separated in the height direction from the receiving portion of the planar antenna element. The composite antenna device according to claim 1, wherein a signal is received at the position where the signal is transmitted.

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