JP3215837B2 - Flying object antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flying object antenna used for a flying object such as an aircraft, a missile, and an unmanned aerial vehicle.

[0002]

2. Description of the Related Art As a flying object antenna, a monopole antenna, a Yagi antenna, a traveling wave loop antenna and the like have been conventionally used. Since these antennas have high directivity, the antenna gain can be increased for radio waves arriving from a specific direction or radio waves radiating in a specific direction. However, these antennas have a structure in which the antenna elements protrude from the body surface.
Therefore, the shape of the antenna element becomes large, especially in a low frequency region, which may adversely affect the flight characteristics of the flying object.

There is a slot antenna as an antenna having no portion protruding from a flying object. The slot antenna is an antenna in which a slot-shaped opening is provided in a vertical tail or the like of a flying object. Since this type of antenna has a low directivity, it is difficult to increase the antenna gain for a radio wave from a specific direction or a radio wave in a specific direction.

In order to prevent the antenna element from projecting from the flying object, a radome is provided at the tip of the flying object, and an antenna for radar or the like is arranged in the radome.

[0005] However, the number of antennas that can be provided in the radome is limited, and it may not be possible to provide all the antennas necessary for the flying object in the radome.

[0006] In order to solve such a problem, the same applicant as the present patent application has filed an inside of an air intake formed of a conductor such as metal and a conductor protruding into the air intake. Antenna element, a power supply device for feeding the antenna element, and a conductor that has a hole smaller than the wavelength used and is electrically connected to the conductor on the inner surface of the air intake and disposed downstream from the antenna element. Consisting of a net,
A patent has been filed for a flying object antenna that uses the inner surface of the air intake as a waveguide.

This antenna uses an inner surface of an air intake formed of a conductor as a waveguide.

[0008] The net made of a conductor disposed downstream of the antenna element prevents the energy of the electromagnetic wave radiated from the antenna element from propagating in the direction of the inside of the fuselage, and is reflected at the back of the antenna element. The present invention prevents an electromagnetic wave radiated from an antenna element of an electromagnetic wave from interfering with each other, thereby adversely affecting the phase characteristics and the like of the antenna.

With such a structure, the directivity characteristics of the flying object antenna are substantially parallel to the axial direction of the air intake. However, by further taking in the specifications such as the shape of the air intake and the position of the feeding point at the design stage,
The directional characteristics can be adjusted to some extent.

In this type of flying object antenna, by providing a partition plate made of a conductor substantially parallel to the axis of the air intake inside the air intake, a plurality of air intakes are provided inside one air intake. It is also possible to form waveguides and provide antenna elements inside each waveguide. By forming in this way, a two-quadrant or four-quadrant radio wave direction-of-arrival detecting device can be configured.

However, since the flying object antenna has a projection such as an antenna element and a net made of a conductor inside the air intake, the air flow may be disturbed.

According to the present invention, the radiation characteristic of the antenna is directional, and furthermore, the radome is not used, and there is no protrusion not only from the airframe of the flying object but also inside the air intake of the flying object. It is an object to propose an antenna for a flying object.

[0013]

An object of the present invention is to provide an opening for taking in air into a flying object, wherein an air intake formed at least in front of the opening is made of a dielectric material; The object of the present invention has been solved by the antenna for a flying object, which comprises a feed element made of a conductor disposed on the dielectric surface or inside the dielectric. The above-mentioned problem is also an annular opening having a cylindrical member at the center for taking in air into the flying object, and at least the front wall of the cylindrical member at the center is formed of a dielectric material. The object of the present invention is also solved by a flying object antenna comprising an air intake which is provided and a feed element made of a conductor disposed on the surface of the dielectric at the front end portion or inside the dielectric.

[0014]

[Function] A conductor is placed on or inside a dielectric,
Since this acts as an antenna, no projection is formed inside the air intake.

[0015]

1 is a perspective view of a flying object on which a flying object antenna according to the present invention can be provided. The air main body MB is provided with four air intake ports AI. Note that only two air intakes AI are visible in the figure.

The air taken in from the air inlet AI is sent to an engine or the like in the flying body through an air duct AD and used.

FIG. 2 is an enlarged perspective view of the air intake portion of the flying object of FIG.

The air intake is only on the bottom surface which is the surface of the flying object main body MB on the upstream side of the air flow. In the middle flow, the side surface perpendicular to the surface of the flying object main body MB is added so that the cross section becomes U-shaped. The height of this side surface increases as it goes downstream, and in the downstream side, the side surface is further added to the ceiling side, so that the cross section is rectangular.

A printed circuit board I made of a dielectric is disposed on the inner surface of the bottom surface S1 of the air intake port AI on the side of the flying object main body MB. An antenna element made of a conductor is arranged on the upper and lower surfaces of the printed circuit board so as to form a log-periodic dipole antenna. Alternatively, a similar antenna is arranged in the dielectric air intake AI itself.
In FIG. 2, the printed circuit board is not shown,
The portion of the antenna element made of a conductor is shown.

FIG. 3 is a conceptual perspective view of only the log periodic dipole antenna shown in FIG. This log-periodic dipole antenna is provided in the air intake AI of FIG.

One central feed line C1, C2 runs parallel to the upper and lower surfaces of the dielectric, respectively, and is connected to a feeder. The branch feed elements A1, A2,..., B1, B2,.

Branch feed elements A1, A3, A5, A7, A
9, A11, A13, A15 and branch feed elements A2, A
4, A6, A8, A10, A12, and A14 branch right and left alternately at right intervals from the central power supply line C1 on the upper surface of the printed circuit board I.

The lengths of the branch feed elements A1, A2,... Change logarithmically. By alternately changing the lengths of the left and right branch feed elements in this manner, the frequency characteristics of the antenna can be flattened.

On the other hand, from the central feeder line C2 on the lower surface of the dielectric, branch feed elements B1, B2,...

At this time, at positions corresponding to the branch feed elements A1, A3 and A5 branched rightward from the central feed element C1 on the upper surface, the branch feed elements B1 and B1 are drawn leftward from the central feed element C2 on the lower face. B3 and B5 are branched. Then, at a position branched to the left on the upper surface, the central feeding element C on the lower surface
It branches from 2 to the right.

The length of the branch feed elements A1, A2,... On the upper surface is equal to the length of the branch feed elements B1, B2,.

The long branch feed element is a bottom surface S on the flying object side.
1 to the adjacent side surfaces S2 and S3, and the longer branch feed element extends to the ceiling side surface S4.

In FIGS. 2 and 3, air is indicated by an arrow AIR.
And the electromagnetic wave is radiated in the direction of the arrow EMW. The directional characteristics can be adjusted to some extent by incorporating the shape of the air intake into the antenna design.

FIG. 4 is a conceptual perspective view of the flying object antenna of the present invention formed as a loop antenna using a printed circuit board.

In this antenna, similarly to the antenna of FIG. 2, the inner surfaces S1, S2, S2 of the air intake AI are provided.
3. Printed circuit board I made of dielectric on inner surface S4 on the ceiling side
Is fixed. Alternatively, the dielectric air intake AI itself is used.

On the upper surface and the lower surface of the dielectric, one central feeding line C1, C2 runs in parallel, and is connected to a feeding device. Loop feed elements D1, D2, D3, and D4 branch off from the central feed lines C1 and C2.

The loop feed elements D1, D2, D3, and D4 branch right and left alternately at right angles from the central feed line C1 on the upper surface of the dielectric, and the branched loop feed elements are formed on the inner surface S2 of the air intake AI. , S3, and S4 to the central feed line C2 on the lower surface of the dielectric.

Since the log-periodic dipole antenna and the loop antenna are outside the scope of the present invention, explanations of their functions and the like are omitted.

FIG. 5 is a perspective view of a flying object provided with a plurality of annular air intakes AI having a cylindrical member at the center. In the case of an air intake having such a shape, the tip of the central cylindrical member is made substantially conical, and a conical antenna is provided there.

FIG. 6 is a perspective view of a conical antenna portion of the flying object antenna according to the present invention which is disposed in the annular air intake port of FIG. This conical antenna has two spiral arms E1, made of a conductor on a dielectric.
E2 is provided. The number of arms can be four. The conical antenna can be made using a flexible synthetic resin or the like. However, the manufacturing method, operation, and the like of the conical antenna are out of the scope of the present invention, and thus further description is omitted.

In the case where the flying object has a plurality of air intakes AI, the antenna for a flying object according to the present invention is provided in each air intake AI, thereby detecting the direction of arrival of radio waves in two quadrants and four quadrants. It is also possible to form
However, this is also outside the scope of the present invention, and a description thereof is omitted here.

[0037]

According to the present invention, there is no projection not only on the surface of the airframe but also inside the air intake while giving the directional characteristics to the electromagnetic waves. Therefore, the antenna gain for an electromagnetic wave arriving from a specific direction is large, and the antenna element does not adversely affect the flight characteristics of the flying object. When a plurality of air intakes are provided, a two-quadrant or four-quadrant radio wave arrival direction detecting device can be formed by installing each of these antennas.

Each antenna of the present invention can also be realized by using the wall surface of the air intake itself as a dielectric printed circuit board and arranging a feed element made of a conductive element on the surface thereof.

[Brief description of the drawings]

FIG. 1 is a perspective view of a flying object on which a flying object antenna according to the present invention can be provided.

FIG. 2 is an enlarged perspective view of a portion of an air intake of the flying object of FIG. 1;

FIG. 3 is a conceptual perspective view of only a log periodic dipole antenna shown in FIG. 2;

FIG. 4 is a conceptual perspective view of a flying object antenna of the present invention formed as a loop antenna.

FIG. 5 is a perspective view of a flying object provided with an annular air intake.

FIG. 6 is a perspective view of the flying object antenna of the present invention formed as a conical antenna.

[Explanation of symbols]

 AI air inlet AIR direction of air flow AD air duct A1, A2, A3 Branch feed element B1, B2, B3 Branch feed element C1, C2 Central feed line D1, D2, D3, D4 Loop feed element E1, E2 Spiral arm EMW Method of radiating electromagnetic wave I Printed circuit board MB Flying object body S1 Bottom surface S2, S3, S4 Side surface

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Koji Kojima 2-16-46 Minami Kamata, Ota-ku, Tokyo Inside Tokimec Inc. (72) Inventor Noriyuki Akabane 2-16-46 Minami-Kamata, Ota-ku, Tokyo (56) References JP-A-56-116303 (JP, A) JP-A-61-245604 (JP, A) JP-A 63-149618 (JP, U) JP-A 1-169804 (JP, U) JP, U) JP-A 4-116410 (JP, U) JP-A-59-39509 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01Q 1/28 G01S 7/03 H01Q 1/38 H01Q 9/27 H01Q 11/10 JICST file (JOIS)

Claims (5)

(57) [Claims] 1. An opening for taking in air into a flying object, wherein an air intake formed at least in front of the opening is made of a dielectric, and the above-mentioned dielectric surface or the inside of the dielectric An antenna for a flying object, comprising a feed element made of a conductor disposed in the antenna. 2. An opening for taking in air into a flying object, wherein at least the front of the opening is an air intake formed of a dielectric, and a dielectric is an inner wall surface of the air intake itself. And a printed circuit board made of a dielectric fixed to the inner wall surface of the air intake, and a central power supply line arranged along the center of the upper surface and the lower surface of the printed circuit board at equal intervals from each central power supply line. flight-body antenna length and branches, characterized in that it consists feed element made of a conductor to form a log periodic dipole antenna comprising a branched feed element which varies logarithmically. 3. An opening for taking air into the flying object, wherein at least the front of the opening is an air intake formed of a dielectric, and a dielectric is an inner wall surface of the air intake itself. Or a printed circuit board made of a dielectric material fixed to the inner wall surface of the air intake, a central feed line arranged along the center of the upper and lower surfaces of the printed circuit board, and a branch from one of the central feed lines A flying object antenna comprising: a conductor that forms a loop along the inner wall surface of the air intake and forms a loop antenna including a loop-shaped feeding element that reaches the other central feeding line. 4. An annular opening having a cylindrical member at the center for taking in air into the flying object, and at least a front end wall surface of the cylindrical member at the center is formed of a dielectric material. An antenna for a flying object, comprising: an air intake port formed as described above; and a feed element made of a conductor disposed on the surface of the dielectric at the front end portion or inside the dielectric. 5. An annular opening having a cylindrical member at the center for taking air into the flying object, wherein at least a front end portion of the cylindrical member at the center is formed of a conical dielectric. An antenna for a flying object, comprising a conductor forming a conical antenna comprising a spiral arm provided on the surface or inside of a dielectric of the cylindrical member.