JP2000165136A - Slot antenna - Google Patents

Abstract

(57) [Summary] (Modifications) [PROBLEMS] In a conventional slot antenna, a current induced or supplied to one side of the slot flows in the same direction on the opposite side of the slot, and an electric field flows in the same direction on both sides of the ground plane. Occurs. These electric fields cancel each other out in a space in the direction of the edge of the ground plane in opposite directions, thereby generating a null point of the electric field. Therefore, the directional characteristics of the conventional slot antenna are directional, and a non-directional slot antenna cannot be realized. Therefore, an omnidirectional slot antenna is provided. SOLUTION: A slot 4 is provided on each of two faces 2 of a hollow rectangular parallelepiped facing each other, and at least one partition plate 5 for partially blocking between the two faces is provided inside the rectangular parallelepiped 4, 2 formed inside 3
The length of the path between the surfaces was set to an electrical length of about 波長 wavelength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slot antenna radiating radio waves from a slot, and more particularly to a non-directional slot antenna.

[0002]

2. Description of the Related Art FIG. 7 shows a structure of a conventional slot antenna. That is, the slot antenna is provided with an elongated slot 12 in a rectangular base plate 11 and a power source 13 connected to a long side sandwiching the slot 12. When power is supplied to the side having a narrow interval between the slots 12, an electric field and a magnetic field are generated in the slot 12. Slot 1
If the length of 2 is formed to be の of the working wavelength, resonance occurs, and radio wave emission equivalent to the case where power is supplied to the center of the half-wavelength dipole antenna can be performed.

[0003]

In the conventional slot antenna, as shown in FIG. 8, a current induced or supplied to one side of the slot 12 flows in the same direction on the opposite side of the slot 12, and the electric field 14a , 14b occur in the same direction on both sides of the main plate 11. These electric fields 14a, 14b
Are opposite to each other in the space in the direction of the end of the base plate 11 and cancel each other, thereby generating a null point of the electric field. Therefore, the directional characteristics of the conventional slot antenna are directional, as shown in FIG. 9, and a non-directional slot antenna cannot be realized.

[0004] Therefore, an object of the present invention is to solve the above problems and to provide a non-directional slot antenna.

[0005]

In order to achieve the above object, according to the present invention, a hollow rectangular parallelepiped is provided with a slot on each of two opposing surfaces, and a portion between the two surfaces is partially blocked inside the rectangular parallelepiped. At least one partition plate is provided, and a length of a path between the two surfaces formed inside the rectangular parallelepiped is set to an electrical length of about 波長 wavelength.

[0006] The partition plate may be arranged parallel to the two surfaces.

[0007] The slot may be provided in contact with a side of the surface.

[0008] A projection may be provided on the surface of the rectangular parallelepiped.

Power may be supplied to only one of the two slots.

[0010] Power may be supplied to each of the two slots in opposite phases.

[0011]

An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

As shown in FIG. 1A, the slot antenna according to the present invention has a rectangular parallelepiped 3 having six surfaces 2 formed by a conductive plate 1, and is provided on any surface 2 of the rectangular parallelepiped 3. The slot 4 is provided, the slot 4 is provided also on the opposing surface 2 thereof, and the partition plate 5 is provided inside the rectangular parallelepiped 3. The surface on which the slot 4 is provided is called a slot surface. FIG. 1B shows the slot surfaces 2a and 2b,
Slots 4a, 4b, three partition plates 5a, 5b, 5c
It is shown.

Each partition plate 5a, 5b, 5c has holes (gap) 6a, 6b, 6c so as not to completely shut off between the two slot surfaces 2a, 2b. The holes 6 allow radio waves to propagate from one side of the partition plate 5 to the other side. Here, one end of the partition plate 5 is inscribed in the rectangular parallelepiped 3, and a hole 6 is formed on the opposite end side of the partition plate 5. Each partition plate 5a, 5b, 5c has a hole 6
a, 6b, 6c are alternately arranged so as not to be continuous in a straight line. Here, the partition plate 5 is arranged parallel to the slot surfaces 2a and 2b.

As shown in FIG. 2, holes 6a, 6b, 6
partition plates 5a, 5b, 5 so that c does not continue in a straight line.
Since “c” is alternately arranged, a bent path 7 is formed inside the rectangular parallelepiped 3. Slot surfaces 2a, 2
The length of the path 7 between b is formed to have an electrical length of about 波長 wavelength.

The operation of the slot antenna will be described.

When a power supply signal is supplied to the slot 4a from a power supply line (not shown), a radio wave is radiated from the slot 4a. This radio wave is radiated toward the outside and inside of the rectangular parallelepiped 3 respectively. The radio wave radiated toward the inside of the rectangular parallelepiped 3 propagates through a path 7 that is regulated by the partition plates 5a, 5b, and 5c and bypasses the holes 6a, 6b, and 6c. The radio wave propagated through the electric length of about に よ り wavelength reaches the slot 4 b through the path 7 and is radiated from the slot 4 b to the outside of the rectangular parallelepiped 3. The phase of the radio wave radiated from the slot 4a to the outside of the rectangular parallelepiped 3 and the phase of the radio wave radiated from the slot 4b to the outside of the rectangular parallelepiped 3 are 180.
Although different in degree, the directions of the electric fields 8a and 8b are the same. Electric field 8
Since a and 8b do not cancel each other, no null point of the electric field is generated. Thereby, as shown in FIG. 3, good omnidirectionality can be obtained. Also, the partition plate 5
Since a, 5b, and 5c are arranged in parallel, unnecessary reflection is reduced and better omnidirectionality can be obtained.

Another embodiment of the present invention will be described.

As shown in FIG. 4A, the partition plate 5
May be provided only once.

As shown in FIG. 4B, the partition plate 5
a to 5n (n is an arbitrary integer) may be provided alternately. Since the radio wave path 7 is folded back as the number of the partition plates 5 increases, the length of the path 7 increases as the number of the partition plates 5 increases when the linear distance between the slot surfaces 2a and 2b is the same. Since the length of the path 7 between the slot surfaces 2a and 2b may be an electrical length of about 1/2 wavelength, the greater the number of the partition plates 5, the shorter the linear distance between the slot surfaces 2a and 2b or the distance between other surfaces. Can be shorter. That is, the diameter of the rectangular parallelepiped 3 can be reduced.

Next, the slot antennas shown in FIGS. 5 (a) to 5 (f) each have projections 9 (9a to 9n) of an arbitrary shape provided on the surface 2 of the rectangular parallelepiped 3. As shown in FIG. 5A, the projections 9 a and 9 b are formed in a plate shape and provided outside the rectangular parallelepiped 3. These projections 9a, 9
b is between the slot surfaces 2a, 2b,
2b.

As shown in FIG. 5B, the protrusions 9c,
9d, 9e, 9f are formed in a plate shape, and are arranged radially outside the rectangular parallelepiped 3 from the ridge line.

As shown in FIG. 5C, the protrusions 9g,
9h is provided outside the rectangular parallelepiped 3 as a solid having a trapezoidal cross section.

As shown in FIG. 5D, the protrusions 9i,
9j is formed in a plate shape, and is arranged outside the rectangular parallelepiped 3 in parallel with the surface 2 of the rectangular parallelepiped 3 from a ridge line.

As shown in FIG. 5E, the protrusions 9k,
9l is formed in a plate shape, and is arranged so as to define a corner inside the rectangular parallelepiped 3. The projections 9m and 9n are
It is formed in a plate shape, contacts the sides of the slots 4a, 4b, and is arranged inside the rectangular parallelepiped 3 so as to be inclined with respect to the slot surfaces 2a, 2b. FIG. 5F shows a case where the projections 9k and 9l are provided without providing the projections 9m and 9n.

The basic operation of each of the slot antennas shown in FIGS. 5A to 5F is the same as the operation described with reference to FIG. Is provided, the flow of the current flowing on the surface of the rectangular parallelepiped 3 can be adjusted, and thereby the slot antenna can have a wider band.

Next, in the slot antenna of FIG. 6, the slot 4 is arranged so as to be in contact with an arbitrary side of the surface 2 of the rectangular parallelepiped 3, in other words, in contact with an arbitrary side of the slot surface. That is, one long side of the slot 4 overlaps the ridge line of the rectangular parallelepiped 3.

The basic operation of the slot antenna shown in FIG. 6 is the same as the operation described with reference to FIG. 2, but the internal space which does not become the path 7 is reduced by disposing the slot 4 in contact with the side of the slot surface. Therefore, the diameter of the rectangular parallelepiped 3 can be reduced accordingly.

In the description of the operation of FIG.
Only the power supply signal is supplied to the slot 4
A power supply signal may be supplied to each of a and 4b, and the power supply signal may be adjusted using a distributor, a power supply line, or the like so that these power supply signals have a phase difference of 180 degrees from each other. The electric wave directed to the inside of the rectangular parallelepiped 3 by each power supply signal is inverted by 180 degrees when radiated to the outside of the rectangular parallelepiped 3 from the slot on the opposite side. become. Further, a path 7 sandwiched between the partition plates 5
When using a radio wave of a wavelength that cannot transmit the electric field, the electric field can be radiated from the two slots 4a and 4b in the same direction. Therefore, omnidirectionality can be obtained over a wider band.

Although the length of the path 7 is formed to be about half the electrical length, the size of each part is changed to change the length of the path 7.
May be formed to any length. Thereby, any directivity other than the non-directionality can be obtained.

By arranging the slot antenna according to the present invention so that the slot 4 extends vertically, it is possible to obtain omnidirectionality in a horizontal plane.

Since the slot antenna according to the present invention is formed by using a hollow rectangular parallelepiped, it can be configured to be lightweight and small in diameter.

Further, by arranging the slot antennas according to the present invention in multiple stages, it is possible to increase the gain.

[0033]

The present invention exhibits the following excellent effects.

(1) Since the radio waves radiated in the opposite directions from the slots on the two surfaces have opposite phases, they do not cancel each other and omnidirectionality is obtained.

[Brief description of the drawings]

FIG. 1 is a view of a slot antenna showing an embodiment of the present invention, FIG. 1 (a) is an external perspective view, and FIG. 1 (b) is a cutaway perspective view.

FIG. 2 is a sectional view of the slot antenna of FIG. 1;

FIG. 3 is a directional characteristic diagram of the slot antenna of FIG. 1;

FIG. 4 is a sectional view of a slot antenna according to another embodiment of the present invention.

FIG. 5 is a sectional view of a slot antenna showing another embodiment of the present invention.

FIG. 6 is an external perspective view of a slot antenna showing another embodiment of the present invention.

FIG. 7 is a front view of a conventional slot antenna.

FIG. 8 is a sectional view showing an electric field generated by the slot antenna of FIG. 7;

FIG. 9 is a directional characteristic diagram of the slot antenna of FIG. 7;

[Explanation of symbols]

 2 surface 3 rectangular parallelepiped 4 slot 5 partition plate 7 path

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tomohiro Fukaya 5-1-1, Hidaka-cho, Hitachi-shi, Ibaraki Hitachi Cable, Ltd. Opto-System Research Laboratory (72) Inventor Toshiyuki Takano 880, Sunasawa-cho, Hitachi-shi, Ibaraki Address Hitachi Cable Co., Ltd. Takasago Plant (72) Inventor Makoto Otani 2-2-1 Jinnan, Shibuya-ku, Tokyo Japan Broadcasting Corporation Broadcasting Center (72) Inventor Ichizo Nogami 2-2-2 Jinnan, Shibuya-ku, Tokyo No. 1 Inside the Japan Broadcasting Corporation Broadcasting Center (72) Inventor Hiroshi Fujita 2-1-1 Jinnan, Shibuya-ku, Tokyo Inside the Japan Broadcasting Corporation Broadcasting Center (72) Inventor Tomohiko Sugimoto 2-chome, Jinnan, Shibuya-ku, Tokyo No. 1 Japan Broadcasting Corporation Broadcasting Center F term (reference) 5J045 AA21 DA03 FA01 JA01 LA01

Claims (6)

[Claims] 1. A hollow rectangular parallelepiped is provided with a slot on each of two opposing surfaces, and the hollow rectangular parallelepiped is provided with two slots inside the rectangular parallelepiped.
A slot provided with at least one partition plate that partially blocks between the surfaces, and wherein the length of the path between the two surfaces formed inside the rectangular parallelepiped is set to an electrical length of about half a wavelength. antenna. 2. The slot antenna according to claim 1, wherein said partition plate is arranged parallel to said two surfaces. 3. The slot antenna according to claim 1, wherein the slot is provided in contact with a side of the surface. 4. The slot antenna according to claim 1, wherein a projection is provided on a surface of the rectangular parallelepiped. 5. The slot antenna according to claim 1, wherein power is supplied to only one of the two slots. 6. The slot antenna according to claim 1, wherein power is supplied to each of the two slots in opposite phases.