JPH0141211Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to an antenna support structure for a small wireless communication device, and is particularly applicable to the metal casing of a small wireless communication device or the body of a car equipped with a small wireless communication device. The present invention relates to a support structure for an antenna provided on a metal body such as a metal helmet of a person carrying a small radio communication device (hereinafter referred to as the metal body around the small radio communication device).

[Prior art]

In general, wireless communication devices that are used while moving, such as hand-held talkies in the VHF band or above, are easy to carry and use, and are as small as possible to reduce damage and other problems during use, and are less likely to come into contact with other objects. Something in shape is required.

It is preferable to integrate the antenna and the metal casing in accordance with this requirement, but as shown in Fig. When used in a state where the antenna is in close proximity _to Figure 1b
As shown, the radiated electric field Ed due to the direct wave Wd and the reflected wave
The vector sum of the radiated electric field Er due to Wr becomes extremely weak and cannot be put to practical use.

For this reason, in the past, a metal casing 2 was used as shown in the second figure.
A retractable antenna 1 is installed in the antenna 1, and the antenna 1 is pulled out to the outside during use. However, with this structure, when using a small wireless communication device in a narrow space such as a car or in a factory, it is difficult to avoid contact with other metal objects. The radiation characteristics may change significantly due to the influence of
Or you may come into contact with a high-voltage object and endanger your life.

[Purpose of invention]

Therefore, the present invention is a compact wireless transmitter that eliminates the risk of the antenna coming into contact with other objects even when used in a narrow space such as a car or in a factory, and avoids bending or damaging the antenna and risking life. The purpose is to provide an aerial support structure for the aircraft.

[Structure of the idea]

In order to achieve the above objectives, the support structure of the present invention
As shown in FIGS. 3 to 5, between the metal casing 2 of the small wireless communication device or the metal body (not shown) around the small wireless communication device and the antenna 1 installed close to it In order to delay the phase of the reflected wave Wr emitted by the antenna 1 and reflected by the metal housing 2 or the metal body, and to make it in phase with the phase of the direct wave Wd directly emitted from the antenna 1, A dielectric 3 which becomes thinner as it goes away from the antenna 1 is inserted and integrated.

[Configuration of Example]

Embodiments of the present invention will be described below with reference to the drawings.
3 to 5 are examples in which an antenna is provided in a metal casing of a small wireless communication device. FIG. 3 is a plan view and an antenna radiation characteristic diagram showing the first embodiment, and is an example applied when horizontal plane unidirectionality is sufficient.

In this first embodiment, between one side of a metal casing 2 of a small wireless communication device and an antenna 1 installed close to the side of the metal casing 2, the radiation emitted by the antenna 1 is reflected by the metal casing 2. By delaying the phase of the reflected wave Wr,
A dielectric 3 whose thickness becomes thinner as it goes away from the antenna 1 is inserted and integrated in order to make it in phase with the direct wave Wd directly radiated from the antenna 1.

Figures 4a and 5a are a plan view and an antenna radiation characteristic diagram showing the second and third embodiments, respectively.
This is an example applied to an almost horizontal non-directional case.
FIG. 4c is a perspective view of the second embodiment, and FIG. 4d is a perspective view of the fourth embodiment.
Fig. 4e is a view taken in the direction of arrow D in Fig. 4c, and E- in Fig. 4d.
It is an E-line sectional view.

The second embodiment shown in FIGS. 4a, c to e is such that between the two opposing sides of the metal casing 2 of the small wireless communication device and the antennas 1, 1 provided close to each other along these sides, In order to delay the phase of the reflected waves emitted by the antenna 1 and reflected by the metal casing 2, respectively, and to make them in phase with the phase of the direct waves directly radiated from the antenna 1, the thickness is distanced from the antenna 1. It is formed by inserting and integrating dielectrics 3, 3 which become thinner as the thickness increases. FIG. 4b is its directivity diagram.

That is, the triangular dielectrics 3, 3 are placed in a metal casing 2.
The hollow wires (elements) 1, 1 are closely attached to the tops of the triangular conductors 3, 3, respectively. In this second embodiment, a dipole antenna with a wavelength close to half a wavelength is used, and the feeding point of the antenna 1 is located in the center of the housing 1, and the feeding lines 4, 4 connected to this are drawn into the housing 2. It is connected to the antenna terminal of the internal communication device.

Further, in this case, in order to reduce the protrusions caused by the antennas (elements) 1, 1, it is preferable to use thin ribbon-shaped antenna elements.

FIG. 5c is a perspective view of the third embodiment, FIG. 5d is a view taken in the direction of arrow D in FIG. 5c, and FIG.
-E line sectional view.

The third embodiment shown in FIGS. 5a, c to e shows two adjacent parallel ridgeline portions of a metal casing 2 of a small wireless communication device, an antenna 1 provided closely along the ridgeline portions,
1, the thickness is used to delay the phase of the reflected wave emitted by the antenna 1 and reflected by the metal casing 2, so that it is in phase with the phase of the direct wave directly radiated from the antenna 1. It is formed by inserting and integrating dielectric materials 3, 3 which become thinner as the distance from the antenna 1 increases. FIG. 5b shows its directivity. The third embodiment is also the same as the second embodiment, except that the cross-sectional shapes of the dielectrics 3, 3 are different.

For mechanical retention, the antennas (elements) 1 and 1 are either glued onto the dielectric surfaces 3 and 3 with adhesive, or attached to the mounting surface using a relatively thin plastic sheet (one that has little effect on radio waves). need to be covered.

Further, the reason why the thickness is made thinner as the distance from the antennas (elements) 1, 1 increases is to adjust the increase in the amount of delay caused by the increase in path length due to oblique incidence. Therefore, when the thickness is kept constant, the dielectric constant may decrease as the distance increases.

In addition, the present invention is a metal casing 2 of a small wireless communication device.
The antenna 1 is not limited to the case where the antenna 1 is installed in close proximity along a metal object such as the body of a car equipped with a small wireless communication device or the metal helmet of a person carrying a small wireless communication device (not shown). This can also be implemented in the same manner when the antenna 1 is provided.

[Effect of the embodiment]

In any of the above embodiments, the antenna 1 has a structure in which it is integrated with the metal casing 2, the vehicle body, or the metal helmet without protruding outward, so that the antenna 1 may contact other objects and bend. There is no risk of damage due to being caught or caught in the
Also, there is no risk of life being put in danger by coming into contact with high-voltage objects.

In addition, in the present invention, the antenna 1 is supported by a metal body such as a metal casing 2, a car body, or a metal helmet through a dielectric 3, so that the radio waves radiated from the antenna 1 to each part of the metal body are The phase of the reflected wave is delayed by 180° by each part of the dielectric body 3, which becomes thinner as it moves away from the antenna 1, and the phase of the reflected wave reflected from each part of the metal body is radially shifted from the antenna 1. Since it is in phase with the emitted direct wave, the radiated electric field becomes much larger, as shown in Figures 3, 4a, and 5a, than in the conventional example shown in Figure 1, which reduces the antenna gain. It can be increased by up to 6 dB and can be put to practical use.

The dielectric material 3 used in the present invention preferably has a high dielectric constant because the higher the dielectric constant, the greater the retardation effect and the thinner the thickness, the smaller the size and the lighter the weight. Further, it is desirable to provide a matching layer (a dielectric layer with a different dielectric constant) on the surface of the dielectric 3 to reduce reflection on the surface.

[Effect of idea]

As described above, according to the present invention, the metal casing 2 of a small radio communication device such as a handy talkie for VHF band or above or the metal body around the small radio communication device and the antenna 1 installed close to it Between,
By delaying the phase of the reflected wave emitted from the antenna 1 and reflected by the metal casing 2 or the metal body,
In order to make the phase of the direct wave more directly radiated, a dielectric material 3 whose thickness becomes thinner as it goes away from the antenna 1 is inserted and integrated, so it can be used in narrow spaces such as inside a car or in a factory. Even if a small radio is used, there is no risk that the radiation characteristics of the antenna 1 will change significantly due to the influence of other metal objects, or that it will come into contact with other objects and be bent or entangled and be damaged. Not only is there no risk of exposing one's life to danger due to contact with a voltage object, but the radiated electric field is also not weakened.

Furthermore, since the antenna 1 can be provided close to the metal surface, the capacity of the antenna increases and the element length can also be shortened.

[Brief explanation of the drawing]

Figures 1a and b are a plan view and a vector diagram of the radiated electric field of the antenna when the antenna is installed very close to the metal casing, respectively, and Figure 2 is a side view showing an example of a conventional antenna support structure. , FIG. 3 is a plan view and an antenna radiation characteristic diagram showing the first embodiment of the antenna support structure of the present invention, FIG. 4a is a plan view and an antenna radiation characteristic diagram showing the second embodiment, and FIG. Figure b is its directivity diagram, Figure 4 c is a perspective view of the second embodiment, and Figure 4
Figure d is a view in the D direction of Figure 4c, Figure 4e is a view of the fourth
Fig. 5a is a plan view showing the third embodiment and a radiation characteristic diagram of the antenna, Fig. 5b is a sectional view taken along the line E-E in Fig. d.
is its directivity diagram; FIG. 5c is a perspective view of the third embodiment;
5d is a view taken in the direction of arrow D in FIG. 5c, and FIG. 5e is a sectional view taken along the line E--E in FIG. 5d. 1...Antenna (element), 2...Metal casing, 3...Dielectric material.

Claims (1)

[Scope of utility model registration request] Reflections emitted from the antenna and reflected by the metal casing or metal body between the metal casing of a small radio communication device or a metal body surrounding the small radio communication device and an antenna installed close to it. A small radio communication device that is integrated with a dielectric whose thickness becomes thinner as it gets farther away from the antenna, in order to delay the phase of the wave and make it in phase with the phase of the direct wave directly radiated from the antenna. Aerial support structure.