WO1998011624A1

WO1998011624A1 - Multiple frequency antenna

Info

Publication number: WO1998011624A1
Application number: PCT/JP1997/003159
Authority: WO
Inventors: Hirotsugu Imahigashi; Jinichi Inoue; Tsuneo Ehara
Original assignee: Nippon Antena Kabushiki Kaisha
Priority date: 1996-09-13
Filing date: 1997-09-08
Publication date: 1998-03-19
Also published as: EP0862239A4; EP0862239A1; DE69732564D1; KR100389940B1; JP3065949B2; KR19990067437A; CN1205118A; EP0862239B1; CN1136628C; JPH1093327A; DE69732564T2

Abstract

In order to stably receive GPS signals and to be attached to an arbitrary position of a car body, a GPS antenna (10) is incorporated in a cover (2) together with a matching substrate (9), etc. An antenna element (1) is connected to the substrate (9). Since the substrate (9), etc., are erected, the grounding effect of the antenna (10) is improved and, at the same time, the antenna (10) does not receive any adverse influence even when the elevation angle to a GPS satellite is low. Since the antenna element (1) is connected to the substrate (9) at an angle from the vertical line, the antenna (10) does not receive any adverse influence even when the elevation angle to the GPS satellite becomes lower.

Description

Description Multi-frequency antenna Technical field

The present invention relates to an antenna capable of receiving four waves of a portable radio telephone band, an FM radio band, an AM radio band, and a GPS band, and is particularly suitable for being applied to a roof antenna attached to a roof of a vehicle body. Background art

There are various types of antennas that can be mounted on the vehicle body.However, if the antenna is mounted on the roof located at the highest position on the vehicle body, the reception sensitivity can be improved, and the roof fan antenna mounted on the roof has been preferred from the past. ing. In addition, since an FM radio and an AM radio are generally installed inside the vehicle, it is convenient to use an antenna that can receive both the FM radio band and the AM radio band. One fantena is widespread.

Recently, car navigation systems and portable radio telephones using the GPS (Global Positioning System) have become widespread.

The GPS antenna is used for mobile phones, and the mobile phone antenna is installed on the vehicle body.

In addition, if a keyless entry system is provided to remotely control the locking and unlocking of the doors wirelessly, a keyless entry antenna is installed on the vehicle body.

By the way, installing such various antennas independently on the vehicle body is not good-looking, and the maintenance and installation work becomes complicated. Therefore, a single antenna can be used for the mobile phone band and FM radio band. A multi-frequency antenna that receives the AM radio band, the GPS band, and the key entry band is desired.

FIG. 7 shows an example of the configuration of this type of multi-frequency antenna described in a conventionally proposed Japanese Patent Application Laid-Open No. 6-132714. In Fig. 7, the telescopic rod antenna 1 0 1 is a three-wave antenna capable of receiving the mobile radio telephone band, FM radio band, and AM radio band, and a planar radiator 102 is a GPS antenna for receiving GPS signals, and a loop radiator. The body 103 is a keyless entry antenna for receiving a keyless entry signal.

Each of these antennas is installed on the upper surface of the main body 100. A metal plate 104 is provided on the upper part of the main body 100. The plane radiator 102 and the loop radiator 100 are provided on the plate〗 04 via a dielectric layer. 3 and are formed. Since the plate 104 functions as a ground plane, the plane radiator 102 and the loop radiator 103 operate as a microstrip antenna. Note that a protective cover 105 is formed on the plane radiator 102 and the loop radiator 103.

However, in the above-described multi-frequency antenna, when the retractable rod antenna 101 is stored so as not to protrude from the upper surface, the rod antenna 1 is placed in the internal space of the mounting portion to which the multi-frequency antenna is attached. 0] is required. Therefore, a multi-frequency antenna can be mounted on the trunk lid / fender of the vehicle body, but it cannot be mounted on a roof or other location where there is no storage space.

By the way, it is known that the elevation angle of the radio wave transmitted from the GPS satellite is often low. However, when the multi-frequency antenna was mounted on a trunk fender, depending on the position of the GPS satellite, there was a risk that the vehicle would block the electric waves from the satellite.

In addition, when the loop radiator 103 for the keyless entry is provided so as to surround the plane radiator 102 as a GPS antenna, the elevation angle of the GPS radio wave is often low as described above. Therefore, there was a problem that the sensitivity of the GPS antenna was significantly adversely affected depending on the position of the GPS satellite.

Therefore, an object of the present invention is to provide a multi-frequency antenna that can be mounted at a high position such as a roof on a vehicle body having no storage space and that does not adversely affect the operation of a GPS antenna. And Disclosure of the invention

In order to achieve the above object, a multi-frequency antenna according to the present invention includes a whip-shaped antenna element capable of receiving three waves of an AM radio band, an FM radio band, and a portable radio telephone band, and And a circuit board provided with at least matching means, demultiplexing means, and amplifying means, and an antenna case in which a GPS antenna is housed. The antenna case comprises a conductive base. And a cover fitted to the base. The circuit board is fixed upright on the base, and a GPS antenna is attached to the base so as to be orthogonal to the circuit board. The GPS antenna housing is formed integrally. In addition, the multi-frequency antenna can be fixed to a roof of a vehicle body, and the GPS antenna storage portion is formed by a protrusion so as to surround the entire circumference of the GPS antenna. The part shields a circuit board arranged on the back surface of the GPS antenna.

Furthermore, the antenna element is inclined by about 20 ° to 35 ° from the upright position.

According to the present invention, since the antenna housing is not required under the multi-frequency antenna, it is possible to mount the antenna at a high position such as a roof where there is no housing space when mounting the antenna on a vehicle body. Become. Therefore, it is possible to prevent the GPS radio wave received by the GPS antenna from being shielded by the attached body such as the vehicle body, so that the GPS radio wave cannot be received.

Furthermore, since the circuit board is arranged orthogonal to the GPS antenna, the grounding effect of the GPS antenna can be improved. Furthermore, even if the GPS radio wave arrives at a low elevation angle, the circuit board is erected and the antenna elements are arranged at an angle, so that the effect on the GPS antenna can be minimized.

In addition, since the circuit board that processes the signal of the GPS antenna is shielded, the GPS antenna can operate stably. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a diagram showing a part of an exploded perspective view showing a configuration of an embodiment of a multi-frequency antenna according to the present invention.

FIG. 2 is an exploded perspective view showing another part of the configuration of the embodiment of the multi-frequency antenna according to the present invention.

FIG. 3 is a cross-sectional view and a front view showing a configuration of an embodiment of the multi-frequency antenna according to the present invention.

FIG. 4 is a diagram showing a configuration of a cover and a base in the multi-frequency antenna according to the present invention.

FIG. 5 is a diagram showing a configuration of a substrate bracket in the multi-frequency antenna according to the present invention.

FIG. 6 is a diagram showing a configuration of a ground bracket in the multi-frequency antenna according to the present invention.

FIG. 7 is a diagram showing a configuration of a conventional multi-frequency antenna. BEST MODE FOR CARRYING OUT THE INVENTION

FIGS. 1 and 2 are exploded perspective views showing the configuration of an embodiment of the multi-frequency antenna according to the present invention.

In these figures, the antenna element 1 is composed of a linear element 111, a wind noise prevention means 12 wound in a coil shape on the element 111, and a flexible synthetic material such as rubber. It is composed of an antenna base 13 molded with resin. In the antenna base 113, a trap coil may be inserted and connected to the element 111. Further, a coil spring for preventing breakage, which is a part of the antenna element 1, may be provided in the antenna bases 113.

From the lower end of such an antenna element 1, fixing screws 114 for attaching the antenna element 1 to the cover 2 are provided so as to protrude.

The electrical length from the tip of the antenna element 1 to the fixing screw 14 which is the base end of the antenna is about 1/4 wavelength of the FM radio band, and the electric length from the fixing screw 114 to the antenna 1-13 The electric length to the lower end of the trap coil is about 1 / 4 wavelengths.

The cover 2 to which the antenna element 1 is fixed has a watertight element connection fitting 2-7 to which a fixing screw 14 provided at the lower end of the antenna element 1 is screwed. The cover 2 is configured to be fitted to a base 3 shown in FIG. 2 having a metal surface or a conductive plating applied to the entire surface.

A board bracket 12 formed by processing a metal plate is fixed to the base 3, and an amplifier board 8 on which an amplification circuit is assembled and a matching device and a duplexer are assembled on the board bracket 12. The matching board 9 is fixed vertically to the board bracket 12. A connection piece 7 for electrically connecting the antenna element 1 is fixed to the matching board 9 by soldering. The connection piece 7 is provided in an upper portion of the element connection fitting 2-7 provided on the cover 2. By screwing the connection screw 4 inserted into the connector via the waterproof washer 5, the element connection fitting 2-7 is electrically connected to the connection piece 7.

The base 3 has a storage section 3-10 for storing a rectangular GPS antenna 10 therein. The GPS antenna 10 is provided in the storage section 3-10 via a wave spring 11 having a waveform. Is stored. When the cover 2 is fitted and fixed to the base 3, the GPS antenna 10 is pressed toward the base 3 by the holding projection formed inside the cover 2, and the GPS antenna 10 is stored. It is held in part 3-10.

Also, with the cover 2 fitted to the base 3, four fixing screws 14 are screwed into the screw holes formed inside the cover 2 from the back side of the base 3. Cover 2 is fixed to base 3. Further, on the back side of the base 3, a fixing screw part 3-9 to be fitted into a mounting hole formed in a body to be mounted such as a vehicle body projects, and the fixing screw part 3-9 has a waterproof part. O-ring 13 is inserted.

Further, a buffer pad 15 made of a flexible material is fitted to the lower end of the base 3 so that the fixing screw 3-9 protruding from the back side of the attached body has a nut 1-9. When the multi-frequency antenna is mounted on the body to be mounted by screwing 6, the wound body can be prevented from being attached to the body to be mounted.

Furthermore, the lower end of the cover 2 is fitted so that the cover 2 is fitted to the base 3 in a watertight manner. A groove is formed on the periphery of the portion, and the waterproof packing 6 is fitted into the groove.

The power cord 18, GPS cable 19, telephone cable 20, and radio cable 21 consist of a through hole formed in the base 3, and a cylindrical fixing screw 3. — It is drawn through 9 to the inside of the attached body.

In this case, the ground cable of the telephone cable 20 and the radio cable 21 is electrically connected to the ground bracket 17 and both cables are bound. It is bound together with the power cord 18 by means 22. A connector for connection is provided at the end of each cable and cord.

FIG. 3 (a) is a cross-sectional view when the multi-frequency antenna of the present invention configured as described above is assembled, and FIG. 3 (b) is a front view thereof. FIG. 4 (a) shows the configuration inside the cover-2, and FIG. 4 (b) shows the configuration as viewed from the top of the base 3. FIG. Hereinafter, the multi-frequency antenna of the present invention will be described with reference to these drawings. As shown in these figures, a connection screw 4 inserted into an element connection fitting 2-7 molded integrally with the cover 2 is screwed to a connection piece 7 fixed to the matching substrate 9. . Therefore, a signal received by the antenna element 1 screwed to the element connection fitting 2-7 is guided to the matching board 9 via the element connection fitting 2-7 and the connection screw 4. Then, in the matching board 9 and the pump board 8 (not shown), each of the received signals that have been demultiplexed and amplified is guided to the inside of the vehicle body as an attached body by the telephone cable 20 and the radio cable 21. I will

In addition, the telephone cable 20 and the radio cable 21 are drawn through the inside of the cylindrical fixing screw 3-9.

The matching substrate 9 and the amplifier substrate 8 are fixed so as to be erected on the substrate bracket 12. At this time, the ground portions of both boards 8 and 9 are electrically connected to board bracket 12 and further grounded to the body to be mounted via base 3.

Further, a GPS antenna 10 is housed and held in a space formed by the cover 2 and the base 3. The GPS antenna 10 has a rectangular shape, and is composed of a projection 3-1 standing on the base 3 so as to surround the GPS antenna 10. The GPS antenna 10 is stored in the rectangular storage section 3-10. The upper end surface of the GPS antenna 10 is pressed by the holding projections 2-2 formed at four places on the inner surface of the cover 2, whereby the GPS antenna 10 is held in the storage portion 3-10. Will be done.

In addition, the outer periphery of the holding projection 2-2 formed on the cover 2 is a projection that can accommodate the GPS antenna 10 having substantially the same shape as the projection 3-1 formed on the base 3.

2-1 are formed facing each other.

In addition, a wave spring 11 is interposed at the lower end of the GPS antenna 10 so that the GPS antenna 10 is securely held in the storage section 3-10. A circuit board on which a circuit for processing a GPS signal is assembled is provided on the lower surface of the GPS antenna 10. Since the circuit board is placed in the conductive storage section 3-10, the storage section is provided. 3-10 will be shielded. Therefore, the GPS antenna 10 operates stably, and the GPS signal is guided into the body through the GPS cable 19.

In this case, the protrusion 3-1 is formed with a groove 3-8 for pulling out the GPS cable 19, and the GPS cable 19 fitted in the groove 3-8 is formed in the cover 2. It is pressed and held by the cable holding projection 2-8 formed so as to protrude further from the projection 2-1.

A groove 2-6 is formed all around the lower end of the cover 2. A waterproof packing 6 is fitted into the groove 2-16, and a protrusion fitted into the groove 2-6 is formed. Department

3 _ 6 is formed on the base 3 over the entire circumference. Therefore, when the force bar 2 is fitted to the base 3 as shown in the figure, the protruding portions 3-6 are pressed against the waterproof packing 6 so as to be fitted in a watertight manner.

The base 3 is made of metal or a conductive plating formed on the entire surface and is made conductive. A flexible pad 15 is disposed on the lower surface of the base 3 and is placed on the attached body. The fixing screw portions 3-9 are inserted into the rectangular mounting holes formed in the mounted body. The base 3 is fixed to the mounted body by screwing the nut 16 into the fixing screw portion 3-9 protruding from the back surface of the mounted body. At this time, the base 3 is connected to the body to be mounted and grounded. In addition, as shown in FIG. 3 (b), the GPS antenna] 0 is arranged almost in parallel with the base 3, but the amplifier board 8 and the matching board 9 are arranged upright. Therefore, the effective area of the ground is increased, and the ground effect of the GPS antenna 10 is improved. Furthermore, even if the GPS satellite has a low elevation angle, the effect of the circuit board on the GPS antenna 10 can be minimized.

In addition, antenna element 1 is attached at an angle of about 20 ° to 35 ° with respect to the vertical line, so that antenna element 1 gives GPS antenna 10 even if the GPS satellite has a low elevation angle. The influence can be prevented as much as possible.

Next, the configuration of the board bracket 12 is shown in FIG. The board bracket 12 is made by processing a metal plate as shown in Fig. 5, and two long sides are provided with a set of circuit board fixing parts 12-1 and 12-2, respectively. Is formed. The circuit board fixing section 12-1 is a fixing section for fixing the matching board 9, and the circuit board fixing section 12-2 is a fixing section for fixing the amplifier board 8. The circuit board fixing portions 1 2-1, 1 2-2 are bifurcated, and the spacing between the bifurcations is substantially equal to the thickness of the circuit boards 8, 9. Then, as shown in the figure, the notches 8-2 and 9-12 formed in the circuit boards 8 and 9 are engaged with the circuit board fixing portions 12-1 and 12-2, respectively. Nine positioning is performed.

After the circuit boards 8 and 9 are mounted on the circuit board fixing portions 12-1 and 12-2, the grounding portions 8-1 and 9-11 of the circuit boards 8 and 9 are connected to the circuit board fixing portions 12-2. — The circuit boards 8 and 9 are fixed to the board bracket 12 by soldering to —1, 1 and 2—2. At this time, the ground portions 8-1, 9-1 of the circuit boards 8, 9 are electrically connected to the board bracket 12.

In addition, one set of cut-and-raised pieces 1 2-3 is used as a cut-and-raised piece for holding down the cable of the GPS cable 8. Further, another set of cut-and-raised pieces 12-4 is a cut-and-raised piece to which a ground bracket 17 described later is soldered and fixed, and a through-hole 12-5 is a through-hole through which various cables are inserted. It is.

Furthermore, the engaging holes 12-7 formed at the three places are engaged with the engaging projections 3-11 formed on the base 3 shown in FIG. 4 (b). The board bracket 12 is positioned on the base 3 by the engagement, and the engaging projections 3-11 It is fixed by caulking.

Next, Fig. 6 shows the structure of the ground bracket 17; Fig. 6 (a) is a side view of the ground bracket 17; Fig. 6 (b) is a front view of the ground bracket 17; FIG. 6 (c) is a top view of the ground bracket 17.

As shown in these figures, the earth bracket 17 holds the holding member 17-3 that holds the slightly thicker radio cable 21 and the slightly thinner telephone cable 20. Holding portions 17-4 are formed. The cables 20 and 21 are held by these holding portions 17-3 and 174, respectively, and soldered from the window 17-2 formed on the side surface. As a result, the ground-bracket 17 is electrically connected to the ground portions of the cables 20 and 21.

An overhang 17-1 protrudes from the side of the ground bracket 17 and the overhang 17-1 is a set of cut-and-raised pieces 1 2 _ of the board bracket 12 shown in FIG. It is soldered to the soldering section 1 2—6 between 4

As a result, the ground bracket 1 is fixed to the board bracket 12 and is also electrically connected. Therefore, the ground portions of the cables 20 and 21 are grounded by the board bracket 12. Also, the cables 20 and 21 can be pulled out vertically.

In the multi-frequency antenna according to the present invention, the antenna element 1 is a three-frequency antenna. However, the present invention is not limited to this, and may be a two-frequency antenna for the AM and FM bands. Industrial applicability

Since the present invention is configured as described above, there is no need for an antenna storage section below the multi-frequency antenna, and when mounting to a vehicle body, mount the antenna at a high position such as a roof where there is no storage space. It becomes possible. Therefore, it is possible to prevent the GPS radio wave received by the GPS antenna from being blocked by the attached body such as the vehicle body.

Further, since the circuit board is disposed orthogonal to the GPS antenna, the grounding effect of the GPS antenna can be improved. Furthermore, GPS radio wave Even if the antenna arrives at a low elevation angle, the circuit board is erected and the antenna elements are arranged at an angle, so that the effect on the GPS antenna can be minimized.

Also, since the circuit board that processes the signal received by the GPS antenna is shielded, the GPS antenna can operate stably.

Claims

The scope of the claims

1. A whip-shaped antenna that can receive at least the AM radio band and the FM radio band can be mounted, and matching means, demultiplexing means, and amplifying means are provided. At least a circuit board provided, and an antenna case in which a GPS antenna is housed inside,

The antenna case includes a conductive base and a cover fitted to the base. The circuit board is fixed to the base by standing upright, and the base is orthogonal to the circuit board. A multi-frequency antenna, wherein a GPS antenna storage portion for mounting the GPS antenna is integrally formed.

2. The multi-frequency antenna according to claim 1, wherein the antenna is fixed to a roof of a vehicle body.

3. The GPS antenna storage section formed on the conductive base is formed by a projection surrounding the entire circumference of the GPS antenna, and is disposed on the back surface of the GPS antenna by the GPS antenna storage section. 2. The multi-frequency antenna according to claim 1, wherein the circuit board is shielded.

4. The multi-frequency antenna according to claim 1, wherein the antenna element is attached to the antenna case at an angle of about 20 to 35 degrees from an upright position.