WO2001071847A1

WO2001071847A1 - Multi-frequency antenna

Info

Publication number: WO2001071847A1
Application number: PCT/JP2001/001362
Authority: WO
Inventors: Hiroshi Shimizu; Yoshio Kadota
Original assignee: Nippon Antena Kabushiki Kaisha
Priority date: 2000-03-17
Filing date: 2001-02-23
Publication date: 2001-09-27
Also published as: DE60100492T2; EP1187253B1; EP1187253A1; JP3464639B2; DE60100492D1; EP1187253A4; JP2001267831A

Abstract

A D net antenna is divided into two and one is provided, as a D net element (13), in an antenna element (1) while the other element is contained, as a lower element (10), in a cover section (2). An E net element (11) is connected to the upper end of the lower element (10). The E net element (11) has a rectangular radiation surface and thereby has substantial nondirectionality in the horizontal plane. The antenna element (1) is fixed removably to the cover section (2), so that the D net element (13) is connected with the lower element (10), thus providing a multi-frequency antenna operating over two wide frequency bands.

Description

Description Multi-frequency antenna Technical field

The present invention relates to a multi-frequency antenna that operates in a first frequency band and a second frequency band, and is mounted on a vehicle that can receive a first mobile radio band, a second mobile radio band, an FMZAM radio band, and a GPS band. This is suitable for application to the multi-frequency antenna described above. 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, it is possible to increase the receiving sensitivity. There. In addition, since FM / AM radios are generally installed in the vehicle body, antennas that can receive both FM and radio bands are convenient, and roof antennas that can receive signals by sharing two radio bands have become popular. I have.

In recent years, car navigation systems and mobile telephones using the GPS (Global Positioning System) have become widespread. In car navigation systems, GPS antennas are installed, and in mobile phones, mobile phone antennas are installed on the vehicle body.

In addition, if a keyless entry system that remotely controls the door lock and unlocking is provided, a keyless entry antenna is installed on the vehicle body.

By the way, installing these various antennas separately on the vehicle body is not only a design problem but also complicates maintenance and installation work. Therefore, using one antenna for mobile phone band, FM / AM Multi-frequency antennas for receiving radio, GPS, and keyless antenna bands have been proposed.

As this type of multi-frequency antenna, a multi-frequency antenna described in Japanese Patent Application Laid-Open No. Hei 6-132714 is known. This multi-frequency antenna is a three-wave antenna that can receive mobile phone band, FM radio band and AM radio band. It consists of an antenna, a planar radiator that is a GPS antenna that receives the GPS signal, and a loop radiator that is a keyless antenna that receives the keyless entry signal.

Each of these antennas is installed on the upper surface of the main body, but a metal plate is provided on the upper part of the main body, and a planar radiator and a loop radiator are formed on the plate via a dielectric layer. Have been. Since this plate becomes the ground plane, the plane radiator and the loop radiator operate as a microstrip antenna. Note that a protection bar is formed on the plane radiator and the loop radiator.

Since such a multi-frequency antenna is provided with a retractable mouth antenna, a space for accommodating the rod antenna is required when mounting. Therefore, it is possible to attach a multi-frequency antenna to the trunk lid / fender of a vehicle body that can form a space, but it cannot be attached to a roof suitable for installing an antenna because there is no storage space for it. That would be. In this case, if a multi-frequency antenna is attached to the trunk lid / fender of the vehicle, the elevation angle of the satellite for GPS is often low, so the radio wave from the satellite is blocked by the vehicle depending on the position of the satellite for GPS. There was a risk of being done.

Therefore, a multi-frequency antenna designed to solve this problem is disclosed in Japanese Patent Laid-Open No. Hei 10-93327.

This multi-frequency antenna is composed of an antenna element provided with a trap coil so as to resonate at multiple frequencies, and a cover section in which a matching board or the like to which the antenna element is attached is incorporated. By fixing this cover to the roof, a multi-frequency antenna can be attached to the roof.

By the way, a plurality of frequency bands are generally assigned to a frequency band used for a mobile phone. For example, in the PDC system (Personal Digital Cellular telecommunication system) in Japan, 800 MHz band (810 MHz to 956 MHz) and 1.4 GHz band (1429 MHz to 501 MHz) are allocated. In Europe, the GSM (global system for mobile communications; 80-MHz (87-96 OMHz)) and the 1.7-GHz (1.71 MHz) ~: The DCS (Digital Cellular System) method of 188 MHz is adopted.

. To operate antennas in such multiple frequency bands, antennas that operate in each frequency band are provided, but the two antennas are connected via choke coils so as not to affect each other's operation It is common. However, it is difficult for a choke coil such as a trap coil to separate signals over a wide frequency band. That is, even if a choke coil is provided between antennas operating in each frequency band, in the case of a wide frequency band such as a mobile telephone band, each antenna can be operated independently over that frequency band. However, there is a problem in that they cannot affect each other and operate satisfactorily. Disclosure of the invention

An object of the present invention is to provide a multi-frequency antenna having a novel configuration that operates over two different wide frequency bands. In order to achieve the above object, an intermediate element between the first element operating in the first frequency band is provided. And a second element having a rectangular enlarged radiating surface operating in a second frequency band higher than the first frequency band. Although the operation principle of the multi-frequency antenna of the present invention is not clear due to such a configuration, it does not affect each other even if the first frequency band and the second frequency band are wide frequency bands such as a mobile telephone band. And work independently. Since the radiation surface of the second element is enlarged, the directivity in the horizontal plane can be made almost non-directional.

Further, in the multi-frequency antenna according to the present invention, the first frequency band is a first mobile radio band, and the second frequency band is a frequency band almost twice as high as the first mobile radio band. It is a mobile radio band. .

Furthermore, if the first element for the low frequency band is divided into two, and one of the divided lower elements is stored in the cover, and the second element is stored in the cover, a compact multi-frequency It can be an antenna. In addition, a circuit board incorporating a duplexer or the like can be accommodated in the space in the cover. Further, when an element operating in a much lower frequency band such as an AMZFM band is provided at the upper end of the first element via a choke coil, a multi-frequency antenna having three or more frequencies can be obtained. Furthermore, even if the GPS antenna unit is provided in the storage space inside the cover, the GPS signal can be received without being affected by other antennas. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a partial sectional view showing a configuration of a first embodiment of a multi-frequency antenna according to the present invention.

FIG. 2 is an enlarged view showing a part of the multi-frequency antenna according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a lower element of a divided D-net element and a configuration of an E-net element in the multi-frequency antenna according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a detailed configuration of a lower element of a divided D-net element in the multi-frequency antenna according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a detailed configuration of an E-net element in the multi-frequency antenna according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a schematic configuration of an E-net element connected to a D-net element in the multi-frequency antenna according to the first embodiment of the present invention.

FIG. 7 shows the impedance characteristics in the frequency band of the D net when the dimensions of the D net element and the E net element in the multi-frequency antenna according to the first embodiment of the present invention are set to specific constants. FIG.

FIG. 8 shows the VS WR characteristics in the frequency band of the D net when the dimensions of the D net element and the E net element in the multi-frequency antenna according to the first embodiment of the present invention are set to specific constants. FIG.

FIG. 9 shows impedance characteristics in a frequency band of the E-net when the dimensions of the D-net element and the E-net element in the multi-frequency antenna according to the first embodiment of the present invention are set to specific constants. FIG. FIG. 10 shows the VSWR in the frequency band of the E-net when the dimensions of the D-net element and the E-net element in the multi-frequency antenna of the first embodiment of the present invention are set to specific constants. It is a figure showing a characteristic.

FIG. 11 shows the directivity in the horizontal plane at the lowest frequency of the D net when the dimensions of the D net element and the E net element in the multi-frequency antenna according to the first embodiment of the present invention are specified constants. It is a figure which shows a characteristic and a measurement mode.

FIG. 12 shows the horizontal plane at the center frequency and the maximum frequency of the D-net when the dimensions of the D-net element and the E-net element in the multi-frequency antenna according to the first embodiment of the present invention are set to specific constants. FIG. 4 is a diagram showing directional characteristics in the inside.

FIG. 13 is a horizontal plane at the lowest frequency and center frequency of the E-net when the dimensions of the D-net element and the E-net element in the multi-frequency antenna according to the first embodiment of the present invention are specified constants. FIG. 4 is a diagram showing directional characteristics in the inside.

FIG. 14 shows the directivity in the horizontal plane at the highest frequency of the E-net when the dimensions of the D-net element and the E-net element in the multi-frequency antenna according to the first embodiment of the present invention are specified constants. It is a figure showing a characteristic.

FIG. 15 is a diagram showing a measurement mode of a directional characteristic in a vertical plane when directly facing the multi-frequency antenna according to the first embodiment of the present invention.

FIG. 16 is a graph showing the relationship between the minimum frequency and the center frequency of the D-net when the dimensions of the D-net element and the E-net element in the multi-frequency antenna according to the first embodiment of the present invention are specified constants. FIG. 3 is a diagram illustrating in-plane directional characteristics.

FIG. 17 shows the maximum frequency of the D-net and the minimum frequency of the E-net when the dimensions of the D-net element and the E-net element in the multi-frequency antenna according to the first embodiment of the present invention are set to specific constants. FIG. 18 is a diagram showing directivity characteristics in a vertical plane at a frequency. FIG. 18 shows the dimensions of the D-net element and the E-net element in the multi-frequency antenna according to the first embodiment of the present invention as specific constants. FIG. 9 is a diagram showing directivity characteristics in a vertical plane at the center frequency and the highest frequency of the E-net at the time of performing.

FIG. 19 is a diagram showing a measurement mode of a directional characteristic in a vertical plane when the multi-frequency antenna according to the first embodiment of the present invention is applied to a side surface. FIG. 20 is a view showing the vertical plane at the lowest frequency of the D net when the dimensions of the D net element and the E net element in the multi-frequency antenna according to the first embodiment of the present invention are specified constants. FIG. 4 is a diagram illustrating directional characteristics.

FIG. 21 is a view showing the vertical frequency at the center frequency and the highest frequency of the D net when the dimensions of the D net element and the E net element in the multi-frequency antenna according to the first embodiment of the present invention are specified constants. FIG. 3 is a diagram illustrating in-plane directional characteristics. '' Fig. 22 shows the center of the lowest frequency of the E-net when the dimensions of the D-net element and the E-net element in the multi-frequency antenna of the first embodiment of the present invention are specified constants. FIG. 5 is a diagram illustrating directivity characteristics in a vertical plane at a frequency.

FIG. 23 is a view showing a vertical plane at the highest frequency of the E-net when the dimensions of the D-net element and the E-net element in the multi-frequency antenna according to the first embodiment of the present invention are set to specific constants. FIG. 4 is a diagram illustrating directional characteristics.

FIG. 24 is a diagram showing a configuration of a multi-frequency antenna according to a second embodiment of the present invention in a partial cross-sectional view.

FIG. 25 is an enlarged view showing a part of the multi-frequency antenna according to the second embodiment of the present invention.

FIG. 26 is a diagram showing a configuration of a lower element of a divided D-net element and a configuration of an E-net element in the multi-frequency antenna according to the second embodiment of the present invention.

FIG. 27 is a diagram showing a detailed configuration of a lower element of the divided D-net element in the multi-frequency antenna according to the second embodiment of the present invention.

FIG. 28 is a diagram showing a detailed configuration of an E-net element in the multi-frequency antenna according to the second embodiment of the present invention.

FIG. 29 is a diagram showing a schematic configuration of an E-net element connected to a D-net element in the multi-frequency antenna according to the second embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a partial cross-sectional view of the configuration of the first embodiment of the multi-frequency antenna according to the present invention, and FIG. 2 is an enlarged view of a part thereof. As shown in these drawings, the multi-frequency antenna 100 according to the first embodiment of the present invention includes a linear antenna element 1 and a resin cover 2 to which the antenna element 1 is detachably attached. It is composed of The antenna element 1 includes a helical element portion 31 formed in a helical shape, and an antenna top 32 provided at an upper end of the helical element portion 31. Further, a molded antenna base 30 is provided at the lower end of the helical element 31. The antenna base 30 includes a bendable flexible element 16 connected to the lower end of the helical element 31, and a choke coil having one end connected to the lower end of the flexible element 16. There are 14 provided. Further, the other end of the yoke coil 14 is connected to a D-net element 13 corresponding to an upper element for the D-net, and a fixed screw portion 12 is provided at a lower end of the D-net element 13. Is provided.

Here, the D-net means the first mobile telephone band according to the above-mentioned GSM method, and the E-net described later means the second mobile telephone band according to the above-mentioned DSC method.

Note that a wind noise preventing means wound in a coil shape is provided on the helical element portion 31. The flexible element portion 16 is a portion that bends when a horizontal load is applied to the antenna element 1 to prevent breakage. The flexible element 16 can be made of a flexible wire cable or coil spring.

A metal base 25 is fitted to the bottom surface of the cover 2 formed by resin molding as shown in FIG. 2, and the base 25 is attached to a vehicle body roof or the like. A cylindrical mounting portion 24 is formed so as to protrude. In addition, a screw is cut on the outer peripheral surface of the base 25, and a signal cable and a power cable led from inside the cover 2 can be passed through a through hole inside the base 25.

Inside the cover part 2, a lower element 10 for the D net and an E net element 11 formed to have a rectangular radiation surface connected near the upper end of the lower element 10 are provided. It is stored. FIG. 3 shows the configuration of the lower element 10 for the D net and the element 11 for the E net. In addition, force par On the upper surface of the portion 2, a screwing portion 2a to which a fixing screw portion 12 provided at the lower end of the antenna base 30 is screwed is provided. The metal screwed portion 2 a is threaded on the inner peripheral surface and is insert-molded and fixed to the cover 2. At the lower end of the screw portion 2a, a connection portion 10 formed at the tip of the lower element 10 and to which a connection insertion portion 12a formed at the tip of the fixing screw portion 12 is screwed. a is located. That is, the connecting portion 10a is fixed to the D-net element 13 in the antenna base 30 by screwing the fixing screw portion 12 provided on the antenna base portion 30 to the screwing portion 2a. It becomes electrically connected via the screw portion 12. As a result, the D-net element 13 constituting one element of the divided D-net antenna is connected to the lower element 10 constituting the other element. Become.

The lower end of the lower element 10 is soldered to a circuit board 21. The circuit board 21 is provided with a filter for demultiplexing the mobile telephone band of the D-net and the E-net and the AM / FM band. ing. The split AM / FM band signal is amplified by an amplifier circuit mounted on an amplification substrate 22 housed in the cover unit 2. Further, the cover unit 2 houses a GPS unit 23 composed of a GPS antenna and a converter unit for converting a received GPS signal into an intermediate frequency signal. In this case, since the E-net element 11 is arranged on the back of the lower element 10, the low elevation angle directivity of the GPS antenna in the GPS unit 23 is not affected. The signal cable connected to the circuit board 21 derives the signals of the mobile telephone band of the D-net and the E-net, the amplifier board 22 derives the signal of the AMZ FM signal band, and the GPS unit 23 From the signal cable connected to, a GPS signal converted to an intermediate frequency signal is derived. These cables are pulled out of the cover part 2 by penetrating the inside of the mounting part 24, and are connected to corresponding devices installed in the vehicle body.

FIG. 3 shows the configuration of the lower element 10 for the D-net and the element 11 for the E-net. Although the configuration of the lower element 10 will be described later, the front end is bent into a plate shape so as to have a substantially L-shaped cross section by processing a metal plate, and is formed at the bent front end. Connection part 1 2a is screwed approximately at the center of the connection part 10a The threaded portion 10 d to be formed is formed. At the lower end of the lower element 10, a soldering piece 10b to be soldered to the circuit board 21 is formed.

The E-net element 11 is formed by processing a metal plate so as to have a substantially rectangular radiation surface, and a connection piece extending from a substantially center of one side thereof is bent in a U-shape. Thus, a holding piece 11a is formed at the tip. The holding piece 11 a is inserted into a cutout window formed in the upper part of the main body piece of the lower element 10 to hold the lower element 10. By soldering the sandwiched portion, the E-net element 11 can be fixed to the lower element 10 and can be electrically connected to each other. The E-net element 11 1 has a substantially rectangular enlarged radiation surface in order to make the directional characteristics in a horizontal plane almost omnidirectional as described later. . The E-net element 11 is formed so that both ends are slightly bent forward and both corners of the upper edge are cut off. This is for storing the E-net element 11 in a narrow storage space formed by the back surface of the lower element 10 and the wall surface of the cover 2. It should be noted that such bending or cutting off both corners does not affect the directional characteristics of the horizontal plane 內.

With such a configuration, the multi-frequency antenna 100 of the first embodiment of the present invention, when the antenna element 1 is screwed into the cover 2, is divided into the D-net elements 13 and D The lower element 10 for the net is connected. That is, in the multi-frequency antenna 100 according to the first embodiment of the present invention, as shown in FIG. 1, the D-net antenna extends from the circuit board 21 to the lower end of the choke coil 14. It works as an antenna. The E-net antenna is an antenna that operates in a range from the circuit board 21 to the upper end of the lower element 10. Further, the antenna for the AM / FM band is an antenna that operates in a range from the circuit board 21 to the antenna top 32. However, there is no resonance in the AM band. Next, a detailed configuration of the lower element 10 and the E-net element 11 in the multi-frequency antenna 100 according to the first embodiment of the present invention will be described with reference to FIGS. 4 and 5. FIG.

FIG. 4 shows a detailed configuration of the lower element 10, and FIG. FIG. 2B is a front view, FIG. 2B is a side view, FIG. 1C is a rear view, and FIG. 1D is a bottom view.

As shown in these drawings, the lower element 10 is formed into a plate shape by processing a metal plate so that the tip is bent so that the cross section becomes substantially L-shaped. The bent distal end is used as a connection portion 10a, and a screw portion 10d to which the connection insertion portion 12a is screwed is formed substantially at the center of the connection portion 10a. I have. In addition, the main body piece 10c extending downward from the edge of the connecting portion 10a is tapered so that the width of the lower end portion is reduced and the upper portion is slightly bent toward the rear side. Have been. A soldering piece 10b to be soldered to the circuit board 21 is formed at the lower end of the body piece 10c. Further, a part of the upper part of the main body piece 10c is cut out to form a cutout window 10e.

FIG. 5 shows the detailed configuration of the E-net element 11; FIG. 5 (a) is a front view of the E-net element 11, FIG. 5 (b) is a side view thereof, and FIG. ) Is a bottom view.

As shown in these figures, the E-net element 11 is formed by processing a metal plate so as to have a substantially rectangular enlarged radiation surface. The end pieces 1 1d and 1 1e are slightly bent forward, and both upper edges are cut off. Further, a portion is extended from substantially the center of the upper side and bent in a U-shape to form a connection piece 11 f and a bent piece 11 b. A part of the leading edge of the bent piece 11b is cut and bent to form the holding piece 11a.

The holding piece 11a is inserted so as to straddle the notch window 10e formed in the upper part of the main body piece 10c of the lower element 10 and the lower element 1 0 is pinched. By soldering the holding pieces 11a around the cutout window 10e in the sandwiched state, the E-net element 11 can be fixed to the lower element 10 and electrically connected to each other. Will be able to do it. The bending angle of the central piece 11c with respect to the connecting piece 11f was made larger than 90 °, and when the E-net element 11 was fixed to the lower element 10, the lower element 10 And the central piece 1 1c of the E-net element 1 1 I am trying to.

By the way, as described above, the multi-frequency antenna 100 of the first embodiment of the present invention operates simultaneously as the D-net and E-net of the mobile telephone band and the 4-frequency antenna of the AMZ FM band, In addition, a GPS unit 23 provided separately can receive GPS signals. In this case, if the equipment for AMZ FM band is not provided and the antenna for AM / FM band is not required, the element for D-net which is one of the elements divided in the antenna base 30 You only need to store 13 The multi-frequency antenna 100 of the first embodiment of the present invention may be a multi-frequency antenna that operates only on the D-net and the E-net in the antenna element 1 as described above. In this case, of course, the length of the antenna element 1 can be shortened accordingly.

Next, the principle configuration of the antenna configuration in the case of a multi-frequency antenna operating only with the D-net and E-net will be described below. The configuration of the antenna in is described.

FIG. 6 (a) shows a principle antenna configuration of the multi-frequency antenna 100 according to the first embodiment of the present invention, which operates on the D net and the E net.

As shown in Fig. 6 (a), the divided D-net antenna has a D-net element 13 at the upper part and a lower element 10 of length L2 at the lower part. L1 is a linear antenna. In addition, the antenna for the D net configured as described above is set up at a slight angle with an angle θ1 from the horizontal plane. An E-net element 11 having a length L3 is connected to a portion where the D-net element 13 and the lower element 10 are connected. The E-net element 11 is spaced apart from the lower element 10 by the length L4 of the connection piece 11f, and is arranged substantially in parallel. The distal end of the connecting piece 11 f is connected to the intermediate portion of the D-net antenna composed of the D-net element 13 and the lower element 10. The configuration of this E-net element 11 is as shown in Fig. 5, but its schematic shape is shown in Figs. 6 (b) and 6 (c), and the rectangular shape forming the enlarged radiation surface is shown. The width of the shape is assumed to be W1. And As shown in the figure, the lower end of the lower element 10 is a feed point for the D-net antenna and the E-net element 11.

The length of the D-net antenna L1, consisting of the D-net element 13 and the lower element 10 shown in Fig. 6, length L1, lower element 10 length L2, and E-net element 11 length L3 And the width Wl, the distance between the antenna for the D-net and the element for the E-net 11 The dimension of L4 is the frequency and angle of the first frequency band of the D-net used and the second frequency band of the E-net 0 Determined according to 1. For example, when the angle 01 is about 76 °, the wavelength at the center frequency of the D-net at 915 MHz is L 1 (32.87 mm), and the wavelength at the center frequency of the E-net at 1795 MHz is L 2 (16 7.23 mm), the length L1 of the antenna for the D-net is approximately 0.202 λ1, the length L2 of the lower element 10 is approximately 0.136 λ2, The length L3 of the element 11 is about 0.102, the width W1 is about 0.162, and the distance L4 between the antenna for D-net and the element 11 for net is about 0.021. Can be 2.

In the multi-frequency antenna 100 according to the first embodiment of the present invention shown in FIG. 1, the length, width, and interval of the divided D-net element 13, lower element 10, and Ε-net element 11 are determined. FIGS. 7 and 9 show the impedance characteristics of the multi-frequency antenna 100 when the above constants are used, and FIGS. 8 and 10 show the VSWR characteristics.

Figure 7 shows the impedance characteristics of the D-net in the 80-band (870-96 mm), and the impedance value is around 50 Ω in the 870-960 MHz frequency band. 50 Ω is the impedance value to be matched. Fig. 9 shows the impedance characteristics of the E-net in the 1.7 GHz band (1 710 MHz to 1 880 MHz). In this case, the impedance value is around 50 Ω.

Furthermore, Fig. 8 shows the VSWR characteristics of the D-net in the 80 OMHz band (87 OMHz to 96 OMHz). Good VSWR value is obtained. Fig. 10 Shows the VSWR characteristics of the E-net in the 1.7 GHz band (1710ΜΗζ to 1880MHz), and a VSWR value of about 2.0 or less was obtained in the frequency band of 1710ΜΗζ to 1880MHz. In particular, a good VSWR value of about 1.5 or less has been obtained in the frequency range from low to midrange. In this case, even if the E-net element 11 is removed, the characteristics of the D-net antenna composed of the lower element 10 of the D-net element 13 are not significantly changed. The antennas can operate independently of each other. However, its operating principle is unclear at present.

Next, in the multi-frequency antenna 100 of the first embodiment of the present invention shown in FIG. 1, the lengths, widths and intervals of the D-net element 13, the lower element 10 and the E-net element 11 are described. FIGS. 11 to 14 show the directivity characteristics of the multi-frequency antenna 100 in the horizontal plane when the above constants are used.

FIG. 11 (a) is a diagram showing a measurement mode in which the multi-frequency antenna 100 is arranged on a ground plane 50 having a sufficient area, and a horizontal angle as a reference. This corresponds to the horizontal angle in the directional characteristics.

Fig. 11 (b) shows the directional characteristics of the multi-frequency antenna 1 • 0 in the horizontal plane at the lowest frequency f = 87 OMHz in the D-net frequency band. As shown, almost omnidirectional directional characteristics are obtained. At this time, the gain of the multi-frequency antenna 100 is about +0.94 dB at a ratio of / 4 whip antenna. FIG. 12 (a) shows the directional characteristics in the horizontal plane of the multi-frequency antenna 100 at the center frequency f = 915 MHz of the D-net frequency band. As shown, almost omnidirectional directional characteristics are obtained. At this time, the gain of the multi-frequency antenna 100 is about +0.5 dB in comparison with the LZ4 whip antenna. FIG. 12 (b) shows the directional characteristics of the multi-frequency antenna 100 in the horizontal plane at the highest frequency f = 960 MHz in the frequency band of the D-net. As shown in the figure, almost omnidirectional directional characteristics are obtained although the level slightly decreases in the 30 ° direction. At this time, the gain of the multi-frequency antenna 100 is about +0.35 dB in the IZ4 whip antenna ratio.

Fig. 13 (a) shows the lowest frequency f = 1 710 MHz in the frequency band of the E-net. 2 shows the directional characteristics of the multi-frequency antenna 100 in a horizontal plane. As shown in the figure, although the level is lower than that of the D-net, almost omnidirectional directional characteristics are obtained. At this time, the gain of the multi-frequency antenna 100 is about 0.8 dB as a Z4 whip antenna ratio.

FIG. 13 (b) shows the directional characteristics in the horizontal plane of the multi-frequency antenna 100 at the center frequency f = 1795 MHz in the frequency band of the E-net. As shown in the figure, almost omnidirectional directional characteristics are obtained. At this time, the gain of the multi-frequency antenna 100 is about 10.6 dB in comparison with the LZ4 whip antenna. FIG. 14 shows the directional characteristics in the horizontal plane of the multi-frequency antenna 100 at the highest frequency f = 1880 MHz in the frequency band of the E-net. As shown in the figure, the level is almost the same as that of the D-net, and almost omnidirectional directional characteristics are obtained. At this time, the gain of the multi-frequency antenna 100 is about +0.3 dB in comparison with the LZ4 whip antenna.

Next, in the multi-frequency antenna 100 of the first embodiment of the present invention shown in FIG. 1, the lengths, widths and intervals of the D-net element 13, the lower element 10 and the E-net element 11 are described. FIGS. 16 to 18 show the directional characteristics in the vertical plane when facing the multi-frequency antenna 100 with the above constants. FIG. 15 is a diagram showing a measurement mode in which the multi-frequency antenna 100 is disposed directly on the ground plane 50 having a sufficient area, and a vertical angle which is a reference of the measurement mode. This corresponds to the vertical angle in the in-plane directional characteristics.

FIG. 16 (a) shows the directional characteristics in the vertical plane of the multi-frequency antenna 100 at the lowest frequency f = 870MHz in the D-net frequency band. As shown in the figure, a good directional characteristic with the maximum level was obtained at a launch angle of about ± 60 °. At this time, the gain of the multi-frequency antenna 100 is about +1.65 dB in comparison with the dipole antenna.

FIG. 16 (b) shows the directivity of the multi-frequency antenna 100 in the horizontal plane at the center frequency f = 915 MHz in the frequency band of the D net. As shown in the figure, a good directivity characteristic with the maximum level was obtained at a launch angle of about ± 60 °. You. At this time, the gain of the multi-frequency antenna 100 is about +0.55 dB in comparison with the dipole antenna.

FIG. 17 (a) shows the directivity of the multi-frequency antenna 100 in the horizontal plane at the highest frequency f = 96 OMHz in the D-band frequency band. As shown in the figure, excellent directional characteristics with the maximum level at a launch angle of about ± 60 ° are obtained. At this time, the gain of the multi-frequency antenna 100 is about +1.1 dB in comparison with the dipole antenna.

FIG. 17 (b) shows the directional characteristics in the horizontal plane of the multi-frequency antenna 100 at the lowest frequency f = 1710 MHz in the frequency band of the E-net. As shown in the figure, although the main beam width is narrower than in the case of the D-net, good directivity characteristics with a maximum level at a launch angle of about ± 60 ° are obtained. At this time, the gain of the multi-frequency antenna 100 is about +3.98 dB in comparison with the dipole antenna.

FIG. 18 (a) shows the directional characteristics of the multi-frequency antenna 100 in the horizontal plane at the center frequency f = 1795 MHz in the frequency band of the E-net. As shown in the figure, good directivity characteristics with the maximum level at a launch angle of about ± 60 ° are obtained. At this time, the gain of the multi-frequency antenna 100 is about +0.04 dB in comparison with the dipole antenna.

FIG. 18 (b) shows the directional characteristics in the horizontal plane of the multi-frequency antenna 100 at the highest frequency f = 188 OMHz in the frequency band of the E-net. As shown in the figure, good pointing characteristics are obtained with the maximum level at launch angles of about + 70 ° and about -165 °. At this time, the gain of the multi-frequency antenna 100 is about +2.65 dB in comparison with the dipole antenna.

Next, in the multi-frequency antenna 100 according to the first embodiment of the present invention shown in FIG. 1, the length, width, and interval of the D-network element 13, the lower element 10, and the E-net element 11 are described above. FIGS. 20 to 23 show the directional characteristics in a vertical plane when the multi-frequency antenna 100 is set on the side surface when the constants are obtained. FIG. 19 shows a measurement mode in which the multi-frequency antenna 100 is arranged on the ground plane 50 having a sufficient area so as to face the side surface, and a vertical direction as a reference. It is a figure which shows an angle, and respond | corresponds to the angle of the perpendicular direction in the directional characteristic in the vertical plane shown below.

FIG. 20 shows the directional characteristics in the vertical plane of the multi-frequency antenna 100 at the lowest frequency f = 870 MHz in the D-net frequency band. As shown in the figure, although there is a slight level difference between the plus and minus elevation directions,

Good directional characteristics with the maximum level at a launch angle of ° are obtained. At this time, the gain of the multi-frequency antenna 100 is about +1.67 dB in comparison with the dipole antenna. '

FIG. 21 (a) shows the directivity of the multi-frequency antenna 100 in the horizontal plane にお at the center frequency f = 915 MHz in the D-band frequency band. As shown in the figure, although there is a slight level difference between the plus and minus elevation directions, good directivity characteristics with the maximum level at a launch angle of about ± 60 ° are obtained. At this time, the gain of the multi-frequency antenna 100 is about +0.47 dB in comparison with the dipole antenna.

FIG. 21 (b) shows the highest frequency f = 96 directional characteristics in the horizontal plane in our Keru multi-frequency antenna 100 to OMH _Z frequency band D net. As shown in the figure, a good directional characteristic with the maximum level was obtained at a launch angle of about ± 60 °. At this time, the gain of the multi-frequency antenna 100 is about +1.64 dB in comparison with the dipole antenna.

FIG. 22 (a) shows the directional characteristics in the horizontal plane of the multi-frequency antenna 100 at the lowest frequency f = 1710 MHz in the frequency band of the E-net. As shown in the figure, although there is a difference in the directional characteristics between the positive and negative elevation directions, the directional characteristic that has the maximum level at a launch angle of about 60 ° is obtained. At this time, the gain of the multi-frequency antenna 1◦0 is about +4.07 dB in comparison with the dipole antenna.

FIG. 22 (b) shows the directional characteristics in the horizontal plane of the multi-frequency antenna 100 at the center frequency f = 1795 MHz in the frequency band of the E-net. As shown in the figure, although the difference in the directional characteristics between the positive and negative elevation directions expands, good directional characteristics with the maximum level at a launch angle of about ± 60 ° are obtained. At this time, the gain of the multi-frequency antenna 100 is about +2.44 dB in comparison with the dipole antenna.

FIG. 23 shows the directivity of the multi-frequency antenna 100 in the horizontal plane at the highest frequency {188} of the E-net frequency band. As shown in the figure, the directional characteristics with the maximum level are obtained at launch angles of about + 75 ° and about 165 °. At this time, the gain of the multi-frequency antenna 100 is about +4.46 dB in comparison with the dipole antenna.

As shown in the directional characteristics in the vertical plane, even if the antenna element 1 is tilted at about 76 ° as shown in the directional characteristics in the vertical plane, the directional characteristics in the vertical plane are reduced. Will be radiated in all directions at a good launch angle of about ± 60 °. Further, the directional characteristics in the horizontal plane are almost omnidirectional as shown in FIGS. 11 to 14. This makes it possible to make the multi-frequency antenna 100 according to the first embodiment of the present invention suitable for operating in a mobile telephone band.

Next, FIGS. 24 and 25 show the configuration of a second embodiment of the multi-frequency antenna according to the present invention.

In the multi-frequency antenna 200 of the second embodiment of the present invention shown in these figures, the antenna element 201 is erected and tilted from the antenna element 1 of the first embodiment. The angle of this inclination is, for example, about 50 degrees. The configuration of the multi-frequency antenna 200 of the second embodiment of the present invention is the same as that of the first embodiment except that the configuration is inclined with respect to the multi-frequency antenna 100 of the first embodiment. The tilting configuration will be described below.

As shown in FIG. 24, the antenna element 201 is erected at an inclination angle of about 50 ° from a horizontal plane, for example. This inclination is achieved because the metal screwed portion 202a insert-molded in the cover portion 202 is tilted and fixed to the cover portion 202. That is, the configuration of antenna element 201 is the same as that of antenna element 1. However, the length of the D-net element 2 13 is different from the length of the D-net element 13. As described above, the configuration of the cover part 202 is different from the configuration of the cover part 2 and the cover part 202 The configurations of the lower element 210 and the E-net element 211, which are housed in the housing, are also different.

FIG. 26 shows the configuration of the lower element 210 and the E-net element 211 in the multi-frequency antenna 200 of the second embodiment of the present invention. Although the detailed configuration of the lower element 210 will be described later, the tip is bent into a plate shape so that the cross section becomes substantially L-shaped by processing a metal plate. At approximately the center of the formed connection portion 210a, a screw portion 210d to which the connection insertion portion 212a is screwed is formed. Further, at the lower end of the lower element 210, a soldering piece 21Ob to be soldered to the circuit board 222 is formed.

Although the detailed configuration will be described later, the E-net element 211 is formed in a substantially rectangular shape by processing a metal plate, and a connection piece extending from substantially the center of one side thereof is bent in a U-shape. Thus, a holding piece 2 1 1a is formed at the distal end. The holding piece 211a is inserted into a cutout window formed in the upper part of the main body piece of the lower element 210, and holds the lower element 210. By soldering the sandwiched portion, the E-net element 211 can be fixed to the lower element 210 and can be electrically connected to each other. The E-net element 211 has a substantially rectangular shape and an enlarged radiating surface to make the directional characteristics in the horizontal plane almost non-directional. The E-net element 211 is formed so that both ends are slightly bent forward, and both corners of the upper edge are cut off. This is for storing the E-net element 211 in a narrow storage space formed by the back surface of the lower element 210 and the wall surface of the cover 202. In addition, such bending or cutting off both corners does not affect the directional characteristics in the horizontal plane.

With such a configuration, the multi-frequency antenna 200 of the second embodiment of the present invention has a divided D-net element when the antenna element 201 is screwed into the cover portion 202. 2 13 and the lower element 2 10 for the D net are connected. That is, in the multi-frequency antenna 200 of the second embodiment of the present invention, the D-net antenna is an antenna that operates from the circuit board 2 21 to the lower end of the choke coil 2 14. . The E-net antenna is The antenna operates in the range from the plate 2 21 to the upper end of the lower element 210. Further, the antenna for the AM / FM band is an antenna that operates in a range from the circuit board 221 to the antenna top 322. However, it does not resonate in the AM band. Next, the detailed configuration of the lower element 210 and the E-net element 211 in the multi-frequency antenna 200 of the second embodiment of the present invention will be described. FIG. 7 is explained with reference to FIG.

FIG. 27 shows the detailed structure of the lower element 210. FIG. 27 (a) is a front view of the lower element 210, FIG. 27 (b) is a side view thereof, and FIG. Is a back view, and (d) is a bottom view.

As shown in these figures, the lower element 210 is formed into a plate shape by processing a metal plate so that the distal end is bent so that the cross section becomes substantially L-shaped. The bent tip is a connection part 210a, and a screw part 210d into which the connection insertion part 212a is screwed substantially at the center of the connection part 210a. Are formed. Also, the main body piece 210c extending downward from the edge of the connecting portion 210a is tapered so that the width of the lower end portion is narrowed, and the lower portion of the main body piece 210c is directed to the back side. It is bent by an angle corresponding to the inclination of element 201. At the lower end of the main body piece 210c, a soldering piece 210b to be soldered to the circuit board 221 is formed. Further, a part of the upper part of the main body piece 210c is cut out to form a cutout window 210e. In addition, the length of the lower element 210 is formed slightly longer than the length of the lower element 10.

FIG. 28 shows a detailed configuration of the E-net element 211, wherein FIG. 28 (a) is a front view of the E-net element 211, and FIG. 28 (b) is a side view thereof. Figure (c) is a bottom view.

As shown in these figures, the E-net element 211 is formed by processing a metal plate so as to have a substantially rectangular enlarged radiation surface. End pieces 2 lid and 2 1 e on both sides are slightly bent forward, and both upper corners are cut off. Furthermore, by extending from the approximate center of the upper side and bending in a U-shape, the connecting piece 2 1 1 f is bent. A piece 2 1 1b is formed. A part of the leading edge of the bent piece 2 11 b is cut and bent to form the holding piece 2 1 a.

This holding piece 2 1 1a is inserted so as to straddle the cutout window 2 10e formed in the upper part of the body piece 2 10c of the lower element 2 10c, and the bent piece 2 1 1b The lower element 210 is sandwiched between them. In the sandwiched state, the holding pieces 2 11 a are soldered around the cutout windows 210 e so that the E-net elements 211 can be fixed to the lower element 210 and can be fixed to each other. It will be possible to make an electrical connection. The bending angle of the central piece 2 11 c with respect to the connecting piece 2 1 1 f is about 90 °, and when the E-net element 2 11 is fixed to the lower element 2 10 As shown in FIG. 6, the lower element 210 and the center piece 211c of the E-net element 211 are arranged substantially in parallel.

By the way, the multi-frequency antenna 200 of the second embodiment of the present invention operates simultaneously as the D-net and E-net of the mobile telephone band and the 4-frequency antenna of the AMZFM band as described above. The GPS signal can be received by a separate GPS unit 222. In this case, if the equipment for AMZF M band is not provided and the antenna for AM / FM band is unnecessary, it is necessary to store only the D-net element 2 13 in the antenna base 230. What should I do? The multi-frequency antenna 200 according to the second embodiment of the present invention may be a multi-frequency antenna that operates only on the D-net and the E-net in the antenna element 201 as described above. In this case, of course, the length of the antenna element 201 can be shortened accordingly.

Next, the principle configuration of the antenna configuration in the case of a multi-frequency antenna operating only with the D-net and E-net will be described below, and the D-net and E-net in the configuration shown in FIG. Let us explain the configuration of the antenna in.

FIG. 29 (a) shows a principle antenna configuration of the multi-frequency antenna 20 ° of the second embodiment of the present invention which operates with the D net and the E net.

As shown in Fig. 29 (a), the split D-net antenna has a D-net element 2 13 at the upper part and a lower element 2 1 at the lower part having a length L 12. It is assumed to be 0 and it is a linear antenna of length L 1 1. In addition, the antenna for the D net configured in this manner is set up obliquely with the angle from the horizontal plane set to angle 02. An E-net element 2 11 having a length L 13 is connected to a portion where the D-net element 213 and the lower element 210 are connected. The E-net element 211 is separated from the lower element 210 by the length L14 of the connection piece 21 1f described above, and is arranged substantially in parallel. The tip of the connection piece 21 1 f is connected to an intermediate portion of a D-net antenna composed of the D-net element 213 and the lower element 210. The configuration of this E-net element 211 is as shown in Fig. 28, but its schematic shape is shown in Fig. 29 (b) and (c), forming an enlarged radiating surface. The width of the rectangle is W2. And, as shown in the figure, the lower end of the lower element 210 is a feeding point for the D-net antenna and the E-net element 211.

The length of the antenna for the D net consisting of the element 213 for the D net and the lower element 210 shown in Fig. 29 is L11, the length of the lower element 210 is L12, and the length of the Enet element 21 is L13 And the width Wl, the distance L14 between the D-net antenna and the E-net element 21 1 are determined by the frequency and angle 0 2 of the first frequency band of the D-net and the second frequency band of the E-net to be used. It is decided according to. For example, when the angle 02 is about 50 °, the wavelength at the center frequency 915 MHz of the D net is L 1 (327.87 mm), and the wavelength at the center frequency 1795 M Hz of the E net is λ 2 (1 67 23 mm), the length L 11 of the antenna for the D-net is about 0.221, and the length L 12 of the lower element 210 is about 0.1 74 X 2, the element 21 1 for the E-net. The length L13 is about 0.120 え 2, its width W2 is about 0.149 え 2, and the distance L14 between the D-net antenna and the E-net element 2 11 is about 0.015 52 It can be.

The reason why the distance L14 is reduced as described above is that the storage space in the cover portion 202 is reduced, and since the storage space is reduced, the width W2 of the E-net element 21 1 is reduced, and The bending angles of 211 d and 211 e are also tight. However, the length of the D-net antenna and E-net element 21 1 is long. It is going to be.

In the multi-frequency antenna 200 of the second embodiment of the present invention shown in FIG. 24, the length and width of the D-net element 2 13, the lower element 210 and the E-net element 211 are different. Assuming that the distance between the antennas is the constant described above, the impedance characteristic and the VS WR characteristic of the multi-frequency antenna 200 in the frequency band of the D-net and the E-net are represented by the multi-frequency antenna 100 according to the first embodiment. Almost the same characteristics as 0 are obtained. In this case, the directional characteristics in the horizontal plane and the directional characteristics in the vertical plane of the multi-frequency antenna 200 in the frequency bands of the D-net and the E-net are the same as those of the multi-frequency antenna 100 according to the first embodiment. And the similar directional characteristics can be obtained. In the first and second embodiments of the multi-frequency antenna according to the present invention described above, the E-net elements 11 and 21 have an enlarged radiation surface of a substantially rectangular shape. Is formed. This is to make the directional characteristics in the horizontal plane almost omnidirectional as described above. However, when omnidirectionality is not required as the directional characteristics in the horizontal plane, the E-net elements 11 1, 2 11 1 May be formed narrower. Also, if the width of the E-net elements 11 and 2 11 is about 0.12 λ 2 or more, the directional characteristics in the horizontal plane will be almost non-directional.

In the multi-frequency antenna according to the present invention, for example, a second antenna which is an antenna for a NET is connected to an intermediate portion of a first antenna which is an antenna for a D-net. The reason why the two antennas operate without adversely affecting each other even in this case is that the second antenna operates in a frequency band approximately twice as high as the frequency band in which the first antenna operates. Is also presumed to be related

Industrial applicability

Since the present invention is configured as described above, a rectangular enlarged radiating surface operating in the second frequency band higher than the first frequency band is provided at an intermediate portion of the first element operating in the first frequency band. Are connected to each other. Although the operating principle is not clear due to such a configuration, even if the first frequency band and the second frequency band are set to a wide frequency band like a mobile telephone band, they operate independently without affecting each other. I will be. Since the radiation surface of the second element is enlarged, the directivity in the horizontal plane can be made almost non-directional.

In this case, if the first element for the low frequency band is divided into two parts and one of the divided lower elements is housed in the cover part, and the second element is housed in the cover part, the compact element can be compact. It can be a frequency antenna. A circuit board in which a duplexer or the like is incorporated can be housed in the space inside the cover.

Furthermore, if an element operating in a much lower frequency band such as the AM / FM band is provided at the upper end of the first element via a choke coil, a multi-frequency antenna having three or more frequencies can be obtained. Furthermore, even if the GPS antenna unit is provided in the storage space in the cover, the GPS signal can be received without being affected by other antennas.

Claims

The scope of the claims

1. a first element operating in a first frequency band;

A second element connected to an intermediate portion of the first element and having a rectangular enlarged radiating surface operating in a second frequency band higher than the first frequency band;

A multi-frequency antenna, comprising:

2. It is assumed that the first frequency band is a first mobile radio band and the second frequency band is a second mobile radio band that is almost twice as high as the first mobile radio band. The multi-frequency antenna according to claim 1, wherein:

3. The first element is divided into two, one of the divided upper elements and

A connection portion to which the upper element can be detachably attached is provided, and a cover portion provided with an attachment portion attachable to an object to be attached is provided. The other lower element divided from the first element provided between the power supply unit and the second element connected to the upper part of the lower element is housed, and the upper element is connected to the lower element. The multi-frequency antenna according to claim 1, wherein the upper element and the lower element are connected to each other by being attached to a part.

4. The third element according to claim 3, wherein a third element operating in a frequency band much lower than the first frequency band is provided at a tip of the upper element via a choke coil. Multi-frequency antenna.

5. The multi-frequency antenna according to claim 3, wherein an antenna unit for GPS is further provided in the cover.

6. The multi-frequency antenna according to claim 4, wherein an antenna unit for GPS is further provided in the front rear cover.

Claims of amendment

[June 22, 2001 (22.06.01) Accepted by the International Bureau: Claim 3 originally filed was amended; Claims 1 and 2 originally filed were withdrawn; The range is unchanged.

(2 pages)]

1. (Delete)

2. (Delete)

3. (after correction) a first element operating in the first frequency band, and a rectangular expansion connected to an intermediate portion of the first element and operating in a second frequency band higher than the first frequency band. A second element having a radiating surface, comprising:

The first element is divided into two, one of the divided upper elements;

A connection part to which the upper element can be detachably attached is provided, and a cover part provided with an attachment part attachable to the attached body,

In the force par portion, another lower element divided from the first element provided between the connection portion and the power supply portion, and the second element connected to an upper portion of the lower element are provided. A multi-frequency antenna, wherein the antenna is housed, and the upper element and the lower element are connected by attaching the upper element to the connection portion.

4. The third element according to claim 3, wherein a third element that operates in a frequency band much lower than the first frequency band is provided at a tip of the upper element via a choke coil. Multi-frequency antenna.

6. An antenna unit for GPS must be provided inside the cover.

Corrected paper (Article 19 of the Convention)

5. The multi-frequency antenna according to claim 4, wherein:

Paper captured (Article 19 of the Convention) Statements under Convention Ί Article 9

Deleted claims 1 and 2 that specifically point to relevant documents. Accordingly, claim 3 was _amended to a form independent of the form citing paragraph 1.