JPH07226624A - Antenna auxiliary system - Google Patents

Abstract

PURPOSE:To increase the gain of an antenna system without exchanging the antenna of the main body of a communication equipment by providing a radiator composed of a conductor provided with a length for resonating to using radio waves, a reflector composed of the conductor provided with the length longer than the radiator and a waveguide composed of the conductor provided with the shorter length and arranging and connecting the radiator parallelly to the whip antenna of the communication equipment. CONSTITUTION:This antenna auxiliary device 15 is composed of the antenna similar to a Yagi-Uda antenna and is constituted by providing the length of iota/2 in the radiator 16 and attaching the reflector 17 linger than lambda/2 and the waveguide 18 provided with the length of 0.4-0.45lambda respectively arranged while maintaining the gap of 0.1-0.25lambda in front and at the back of the radiator to a boom 19. The radio waves radiated from the whip antenna 13 of the communication equipment are absorbed by the connected radiator 16, the radiator 16 is operated as the radiator of the antenna auxiliary device 15 and the radiated radio waves are reflected by the reflector 17 and radiated in the direction of the director by the director 18 for resonating to the radiated radio waves.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna auxiliary device used in addition to an existing antenna.

[0002]

2. Description of the Related Art Although various types of antennas are used in radio equipment, a whip antenna having a length of λ / 4 is the most basic antenna together with a dipole antenna having a length of λ / 2. , Used as a standard when expressing the performance of an antenna. Since the whip antenna is small and has no directivity, it is often used for a wireless device that is moved and used. Further, when further miniaturization is required, a so-called shortened antenna is used in which the electrical length is increased by inserting an inductance or the like into the whip antenna, and as a result, the mechanical length is shortened.

Since such a small whip antenna naturally has a low gain, a higher performance antenna may be required depending on the situation of use. When improving the gain of the antenna, a so-called omnidirectional antenna in which the gain in all directions is increased by increasing the number of radiators that enter and emit radio waves, and a radiator that emits and emits radio waves There is a so-called directional antenna in which the gain in a specific direction is increased by setting the number of 1 to 1 to narrow the incoming and outgoing direction of the radio wave.

The λ / 4 whip antenna, λ / 2 dipole antenna, directional antenna and omnidirectional antenna will be described. In the present specification, the electric length is used to represent the length of the antenna unless otherwise specified.
FIG. 1 is a schematic explanatory view of a λ / 4 whip antenna and a λ / 2 dipole antenna. (A) shows λ / 4
Whip antenna, (b) is an outline of a λ / 2 dipole antenna. These antennas are basically composed of elements having a length of λ / 4. The λ / 4 whip antenna shown in (a) is composed of a single conductor 1 having a length of λ / 4. The λ / 2 dipole antenna shown in (b) is composed of two conductors 2 and 3 having a length of λ / 4.

FIG. 2 is a schematic explanatory view of a directional antenna and an omnidirectional antenna. (A) is a typical directional antenna, Yagi-Uda antenna, and (b) is a typical antenna. It is an outline of a collinear antenna which is a directional antenna. The Yagi-Uda antenna 4 shown in (a) is shown in FIG.
Two conductors 2 and 3 which compose the λ / 2 dipole antenna shown in (b), and reflections longer than λ / 2, which are arranged before and after the two conductors 2 and 3 with a spacing of 0.1 to 0.25 λ. And a waveguide 6 having a length of 0.4 to 0.45λ are attached to the boom 7.
The collinear antenna 8 shown in (b) uses the conductor portion 9 of the whip antenna shown in FIG. 1 (a) as a feeding portion, and the dipole antenna 10 is connected to the tip thereof. The number of directors in the Yagi-Uda antenna and the number of dipole antennas in the collinear antenna are not limited to those shown in (a) and (b), and any number can be used.

In these antennas, G is a high-frequency power source for supplying high-frequency power to the antenna.
Λ / 4 whip antenna shown in (a) and FIG.
In the case of the collinear antenna shown in (b), the λ shown in FIG. 1 (b) is placed between the base of the conductor 1 or 9 and the ground.
In the case of the 1/2 dipole antenna and the Yagi-Uda antenna shown in FIG. 2A, high frequency power is supplied between the two conductors 2 and 3.

The supplied high frequency power resonates at a high frequency having a wavelength corresponding to the electric length of the antenna and is radiated into the air.
The current distribution at that time has a maximum value at the feeding point and a minimum value at the terminal end, as indicated by the broken line in these figures. In the case of the λ / 4 whip antenna shown in FIG. 1 (a), the λ / 2 dipole antenna shown in FIG. 1 (b), and the collinear antenna shown in FIG. 2 (b), the radiated radio waves are mainly It is radiated over the entire circumference in the direction perpendicular to the antenna element. On the other hand, in the Yagi-Uda antenna shown in FIG. 2 (a), the high frequency power supplied to the radiator, which is a λ / 2 dipole antenna, is reflected by the reflector having an electrical length longer than the supplied high frequency. At the same time, the waveguide having an electric length shorter than the supplied high frequency is excited by mutual coupling and is radiated only in the direction of the waveguide.

By the way, some devices using the whip antenna have a structure in which the antenna can be replaced and a device in which the antenna cannot be replaced. Typical examples of devices in which the antenna cannot be replaced include mobile phones and specific low-power communication devices, which have become popular recently. Since these communication devices transmit and receive with very low power, communication may not be possible in a place in the shadow of a building. However, since these communication devices have a structure in which the antenna cannot be replaced, communication cannot be ensured by replacing the antenna with a larger gain.

Further, even in a communication device having a structure in which the antenna can be exchanged, there are various shapes of connectors for attaching the antenna to the communication device body. Since the shape of the connector needs to be the same, the number of types of replacement antennas to be applied to various types of communication devices increases.

FIG. 3 shows a conventional example of an antenna auxiliary device for improving the gain of an antenna of a communication device without exchanging the antenna. This antenna auxiliary device uses the whip antenna 1 of the communication device as a radiator of the Yagi-Uda antenna 11, and is constructed by combining the antenna 1 of the communication device with the reflector 5 and the director 6 and attaching it to the boom 7. Has been done. By the way, as a whip antenna used in a communication device, λ /
4 is the most common, but in addition to this, other electrical lengths such as 5λ / 8, electrical lengths by inserting an inductance to reduce the mechanical length, or electrical capacitances by inserting a capacitance Some have been shortened. Thus, it is not possible to obtain the desired result even if the whip antenna having various configurations is used as the radiator.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to cope with such a situation, that is, what kind of antenna the communication device main body has without replacing the antenna attached to the communication device main body. It is an antenna auxiliary device that can improve the gain of the entire antenna system regardless of whether or not

In the antenna auxiliary device of the present invention, the whip antenna attached to the communication device main body is combined with the radiator of the antenna auxiliary device formed separately from the whip antenna, and the antenna auxiliary device is connected to the communication device main body. By using it virtually as an antenna attached to
Improve the net gain.

Radio waves radiated from an antenna attached to the main body of the communication device are supplied to an antenna auxiliary device coupled to this antenna, and the antenna auxiliary device supplied with the radio waves functions as a radiator having a gain.

The Yagi-Uda antenna, which is a typical directional antenna, is the most common type of antenna auxiliary device, but there is no other typical directional antenna such as an array antenna or a collinear antenna. It goes without saying that it is also applicable to a directional antenna. Furthermore, when the shape of the antenna auxiliary device is excessively large due to usage conditions, an electrical shortening means using an inductor or a mechanical shortening means by bending,
The shape can be miniaturized.

[0015]

EXAMPLES Examples of the present invention will be described below. Shown in FIG. 4 is an outline of an example in which the antenna auxiliary device 12 of the present invention is implemented in the simplest mode for explaining the principle of the present invention. This antenna auxiliary device 12 has a wavelength of 1
A conductor 14 having a length of
4 is coupled to the whip antenna 13 attached to the communication device body. This coupling is the whip antenna 13
In parallel with the current distribution of the conductor 14 of the antenna auxiliary device 12, that is, the upper end of the whip antenna 13 and the upper end of the conductor 14 are at the same height as shown in the figure. The whip antenna 13
And the conductor 14 are brought close to each other. The distance between the whip antenna 13 and the conductor 14 should be as close as possible in consideration of impedance matching. In this way, the antenna auxiliary device 12 coupled to the whip antenna absorbs the radio wave emitted by the whip antenna 13 and re-radiates the absorbed radio wave.

The antenna auxiliary device 12 is composed of a conductor 14 having a length of 1/2 of the wavelength of the used radio wave. That is, the antenna auxiliary device 12 is a resonator having a length of λ / 2 of the radio wave used. Therefore, the antenna auxiliary device 12 resonates with the absorbed electric wave, and functions as a substantial antenna for the resonated electric wave, in other words, as a virtual antenna with respect to the communication device to which the whip antenna 13 is attached. And improve the substantial gain.

In order for the antenna auxiliary device 12 to exert a sufficient function, it is necessary that the antenna auxiliary device 12 efficiently absorbs the radio wave radiated from the whip antenna 13. On the other hand, the whip antenna 13 generally has a length of λ / 4, but the whip antenna 13 has a shortened mechanical length as described in the conventional example shown in FIG. Since some antennas have other electrical lengths such as 8, the antenna coupling device 12 does not always have good coupling simply by being brought close to the whip antenna 13.

When the conductors are brought close to each other, in addition to the capacitance and self-inductance of each conductor, there are capacitance and mutual impedance generated between the conductors. Such impedance cannot be neglected in the antenna used at high frequency, and this point is the same in the case of the antenna auxiliary device 12 of the present invention, that is, the whip antenna 13 and the antenna auxiliary device 1
In order for 2 to operate in the desired state, impedance matching must be achieved. In such cases,
It is necessary to change the position of the antenna auxiliary device 12 with respect to the whip antenna 13 to find the best placement.

FIG. 5 shows an outline of an embodiment in which the antenna auxiliary device 15 of the present invention is constructed with a Yagi-Uda antenna structure. This antenna auxiliary device 15 has a structure similar to that of the Yagi-Uda antenna 4 described with reference to FIG. 2 (a) and has a radiator 16 having a length of λ / 2 and 0.1 before and after the radiator 16.
A reflector 17 having a length of λ / 2 and a director 18 having a length of 0.4 to 0.45 λ, each of which is arranged at a distance of ˜0.25 λ. ing. And this antenna auxiliary device 15
Unlike the Yagi-Uda antenna radiator, the radiator is not a dipole configuration but a single conductor.

The radio wave radiated from the whip antenna 13 of the communication device is absorbed by the radiator 16 of the antenna auxiliary device 15 connected to the whip antenna 13, and the radiator 16 which has absorbed the radio wave is radiated by the antenna auxiliary device 15. The radio wave emitted from the radiator 16 operates as a reflector and the reflector 1
The wave is reflected by 7 and is emitted in the direction of the wave director by the wave director 18 that resonates with the emitted radio wave.

The boom 19 is provided with a fixing tool (not shown) for fixing the antenna auxiliary device 15 to the whip antenna 13 of the communication device, and the whip antenna 13 is fixed by using this fixing tool. On the other hand, the antenna auxiliary device 15 is fixed at an optimum position. Since the radiator 16 operates as the radiator of the Yagi-Uda antenna at the fixed position, it is common between the radiator 16 and the reflector 17.

In the above-described embodiments, the present invention is applied to the Yagi-Uda antenna structure, but there are collinear antennas and array antennas other than the Yagi-Uda antenna as antennas that can realize high gain.
These, including the Yagi-Uda antenna, are generally called array antennas, and the directivity is different due to the different arrangement of the elements constituting the antenna in addition to the different high-frequency power feeding methods. Therefore, the feeding method and the arrangement of elements for implementing the present invention using these antennas are different. An outline of an example in which the present invention is implemented using a collinear antenna and an array antenna will be described with reference to FIGS. 6 and 7.

FIG. 6 shows an outline of an example in which the present invention is implemented using a collinear antenna. The antenna auxiliary device 20 is configured so that the radiator 2 having a length of λ / 2 can be brought close to the tip of the whip antenna 13 of the communication device and coupled thereto. The radio wave radiated from the whip antenna 13 of the communication device is absorbed by the radiator 21 of the antenna auxiliary device 20 that is coupled close to the tip of the whip antenna 13, and the radiator 2 that has absorbed the radio wave.
1 resonates and radiates radio waves all around. In the antenna auxiliary device 20 shown in this embodiment, the radiator 21 having a length of λ / 2 is brought close to and coupled to the tip of the whip antenna 13 of the communication device. It is also possible to connect a part of the container 21 to the whip antenna 13 in parallel and to combine them. Further, the antenna auxiliary device 20 can have a multi-stage collinear antenna configuration.

FIG. 7 shows an outline of an example in which the present invention is implemented by using an array antenna. This antenna auxiliary device 22 is different from the antenna auxiliary device of the Yagi-Uda antenna structure described in FIG. 5, in which a plurality of radiators 23, 23, 23 ... Having a length of λ / 2 are attached to the boom 24. Are arranged in parallel in one plane by
One of these radiators is the whip antenna 1 of the communication device.
It is configured to couple to three.

Radio waves radiated from the whip antenna 13 of the communication device are radiators 23, 23, 23 ... Of the antenna auxiliary device 22 coupled to the whip antenna 13.
The radiator 23, which is absorbed by one of the antennas and absorbs the radio wave, resonates with the radio wave to operate as the radiator of the antenna auxiliary device 22, and radiates the radio wave to another radiator. By repeating this operation, all the radiators operate as radiators. The absorbed and resonated radio waves are radiated in a direction perpendicular to the plane in which the radiator of the antenna auxiliary device 22 is arranged.

The Yagi-Uda antenna described above,
When using a collinear antenna or an array antenna, the shape of the antenna auxiliary device may be excessively large depending on the usage conditions. In such a case, the mechanical length can be shortened by inserting the inductance, or the antenna auxiliary device in which the radiator, the reflector and the director are bent can be miniaturized.

FIG. 8 shows another embodiment in which the antenna auxiliary device of the present invention is constructed by using the Yagi-Uda antenna structure shown in FIG. This antenna auxiliary device 25 is a radiator similar to the antenna auxiliary device 15 shown in FIG.
It consists of a reflector 33, a director 34 and a boom 35 to which they are attached, but the radiator is a normal Yagi-
Same as Uda antenna, λ / 2 dipole antenna conductor 3
1 and 32, and a coupler 26, which is a λ / 2 dipole antenna 29 or 30 that is separately coupled to the whip antenna 13 of the communication device, is separately configured, and the radiators 31 and 32 and the coupler are coupled to each other. 26 is connected by a cable 28.

With this configuration, the antenna auxiliary device can be used even when it is difficult to bring the antenna auxiliary device 27 close to the whip antenna 13 of the communication device to couple the antenna auxiliary device 27.

In the embodiment shown in FIG. 8, the combiner 2
6 uses a λ / 2 dipole antenna,
The dipole antenna is twice as long as the λ / 4 whip antenna. Therefore, depending on how the whip antenna is attached, the coupler 26 may not be able to approach the whip antenna. In such a case, the length of the machine is shortened by bending the coupler or inserting an inductance. It is also possible to use a λ / 4 whip antenna for the coupler.

FIG. 9 shows another embodiment of the antenna auxiliary device of the present invention shown in FIG. In this antenna auxiliary device 36, an amplifier 37 is inserted in the middle of cables 38 and 39 connecting the radiator of the antenna auxiliary device shown in FIG. 8 and the coupler 26. With this configuration, the antenna auxiliary device can exert a stronger function. Although the embodiment shown in FIGS. 8 and 9 is constructed by using the Yagi-Uda antenna structure, in addition to this, an array antenna structure, a collinear antenna structure, etc.
It can be implemented using other antenna structures.

The radiator, reflector and director of the antenna auxiliary device of the embodiment shown in FIG. 5 are attached to the boom, and in a conventional Yagi-Uda antenna, these elements and the boom are insulated. There is. However, since all of these radiators, reflectors and directors have an electrical length of about λ / 2, as shown in FIG. 1 or FIG. The current distribution at the location where it is attached to the boom is maximum, that is, the potential is zero. Therefore, except when the radiator has a dipole antenna configuration as in the antenna auxiliary device shown in FIGS. 8 and 9, the radiator, the reflector, and the director are electrically connected to the boom. can do.

FIG. 10 shows an embodiment in which the radiator, reflector and director are electrically connected to the boom in this way. This antenna auxiliary device 40 includes a radiator 41 and a reflector 4.
2 and the central portions of the director 43 are electrically connected to and attached to the boom 44. With such a configuration, the configuration of the antenna auxiliary device is simplified.

In the antenna assisting device 45 shown in FIG. 11, a radiator 46, a reflector 47, and a director 48 are integrally formed by a metal foil, and all of them are formed on an insulating thin plate 49. By doing so, the configuration can be further simplified, and it is easy to carry and manufacture. Further, by forming the antenna auxiliary device configured as described above in a film shape and adhering it to a glass plate or sandwiching it inside the glass plate, it is easy to use the antenna auxiliary device of the present invention in an automobile or the like. Become.

Although the embodiments shown in FIGS. 10 and 11 are all for the Yagi-Uda antenna type antenna auxiliary device, the configuration shown here is for other types of antenna auxiliary devices, for example, FIG. It is also applicable to the array type antenna auxiliary device shown in FIG.

The configurations of the antenna auxiliary devices described in the above embodiments are listed together as follows. (1) An antenna auxiliary device in which a radiator made of a conductor having a length that resonates with a used radio wave is arranged in parallel with a whip antenna of a communication device and coupled. (2) A radiator made of a conductor having a length that resonates with the radio wave used, a reflector made of a conductor having a length larger than the radiator, and a director made of a conductor having a length smaller than the radiator. Owned Yagi-Uda antenna type antenna auxiliary device. (3) An array antenna in which a plurality of radiators that resonate with the radio wave used are arranged in parallel in the same plane, and one of the arranged radiators is arranged in parallel with the whip antenna of the communication device and coupled. Type antenna auxiliary device. (4) A Yagi-Uda antenna type antenna auxiliary device in which the radiator, the reflector, and the director are fixed to the boom and electrically connected. (5) An array antenna type antenna auxiliary device in which a radiator, a reflector and a director are fixed to a boom and electrically connected. (6) A Yagi-Uda antenna type antenna auxiliary device in which the radiator, the reflector, the director, and the boom are formed of a conductive foil, and the conductive foil is provided on an insulating plate. (7) An array antenna type antenna auxiliary device in which the radiator, the reflector, the director, and the boom are formed of a conductive foil, and the conductive foil is provided on an insulating plate. (8) An antenna auxiliary device in which a conductor having a length that resonates with a used radio wave is arranged and coupled to the tip of a whip antenna of a communication device. (9) A conductor that has a length that resonates with the used radio wave and that is arranged and coupled in parallel with the whip antenna of the communication device,
An antenna auxiliary device comprising a Yagi-Uda antenna and a cable connecting a conductor and the Yagi-Uda antenna. (10) A conductor that has a length that resonates with the used radio wave and that is arranged in parallel with and coupled to the whip antenna of the communication device, a Yagi-Uda antenna, and a cable that connects the conductor and the Yagi-Uda antenna. Antenna auxiliary equipment having an amplifier inserted in the cable.

[0036]

As is apparent from the above description, the antenna auxiliary device of the present invention is brought close to and coupled to the whip antenna attached to the communication device main body, and this antenna auxiliary device is connected to the antenna connected to the communication device. By imagining, the gain of the antenna system can be improved without any modification to the communication device body including the whip antenna.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a λ / 4 whip antenna and a λ / 2 dipole antenna.

FIG. 2 is a conceptual diagram of a Yagi-Uda antenna and a collinear antenna.

FIG. 3 is a conceptual diagram of a conventional antenna auxiliary device.

FIG. 4 is a conceptual diagram of an antenna auxiliary device of the present invention.

FIG. 5 is a conceptual diagram of an embodiment in which the present invention is configured with a Yagi-Uda antenna structure.

FIG. 6 is a conceptual diagram of an embodiment in which the present invention is configured with a collinear antenna structure.

FIG. 7 is a conceptual diagram of an example in which the present invention is configured with an array antenna structure.

FIG. 8 is a conceptual diagram of another embodiment in which the present invention is configured with a Yagi-Uda antenna structure.

FIG. 9 is a conceptual diagram of yet another embodiment in which the present invention is configured with a Yagi-Uda antenna structure.

FIG. 10 is a conceptual diagram of an example in which the present invention is configured with an integrated Yagi-Uda antenna structure.

FIG. 11 is a conceptual diagram of an example in which the present invention is configured with a thin Yagi-Uda antenna structure.

[Explanation of symbols]

1,13 Whip antenna 2,3,29,30,31,32 Dipole antenna 5,17,33,42,47 Reflector 6,18,34,43,48 Waveguide 7,19,24,35,44 Boom 12,15,20,22,25,36,40,45 Antenna auxiliary device 14,16,21,41,46 Radiator 26 Coupler 28,38,39 Cable 37 Amplifier 49 Insulating thin plate G High frequency power supply

Claims (1)

[Claims] 1. A radiator comprising a conductor having a length that resonates with a radio wave used, a reflector comprising a conductor having a length larger than the radiator, and a conductor having a length smaller than the radiator. An antenna auxiliary device comprising a director, wherein the radiator is arranged and coupled in parallel with a whip antenna of a communication device.