JPH11274831A - Airframe structure integrated antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease air resistance, reduce icing and antenna weight and more over reduce the possibility of radar detection by integrating the airframe and an antenna. SOLUTION: One part of an airframe outer plate 1 is opened, and a circuit board is attached through an attachment frame structure to the inside of that opening part 11. In this circuit board, with a conductor plate as a center, an antenna element formation board 14 is laminated on the upside and plural antenna element 15 are formed in the shape of array on its surface. Such an antenna element 15 is set so as not to be parallel and orthogonal with the arriving direction and polarizing direction of electromagnetic waves estimating an edge and a face in its lengthwise direction. A circuit formation board is provided on the lower side of the conductor plate, a high frequency electrode circuit is mounted on the surface, and its power feeding part is electromagnetically connected with the antenna element 15 by a connecting pin. Besides, an electronic circuit protective casing is provided for protecting the electronic circuit. Further, a radome 22 formed from a member transmitting electromagnetic waves is mounted at the opening part 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a body structure integrated antenna having a structure for reducing a radar cross-sectional area in a specific direction, for example, in an aircraft, a flying object, a space device, or the like.

[0002]

2. Description of the Related Art Conventionally, an antenna mounted on, for example, an aircraft, a flying object, a space device, or the like is configured as shown in FIG. In FIG. 1, reference numeral 1 denotes a metal body skin, which shows a body body structure of a conventionally used aircraft or the like. The main body of the blade antenna 2 is mounted on the body outer panel 1 via an antenna mount 3. That is, conventionally, the blade antenna 2 is manufactured as an antenna unit independent of the body outer panel 1, and it is attached to the surface of the body outer panel 1 also manufactured separately. Therefore, the antenna is not integrally manufactured as a fuselage,
Appears as a protrusion on the surface of the fuselage skin 1.

[0003]

As described above, the conventional antenna mounted on an aircraft or the like appears as a protruding structure on the surface of the body outer panel 1, so that the air resistance increases and ice is easily formed, In addition, there is a problem that the weight increases.

Further, the antenna becomes a projection, and the reflection of radio waves caused by the internal structure of the antenna itself increases the radar cross-sectional area with respect to radar waves (electromagnetic waves).
As a result, the possibility of radar detection increases, which is a serious problem when the position confidentiality of the aircraft is required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and can integrate an airframe and an antenna, reduce air resistance, reduce icing, and reduce weight, and can reduce radar cutoff. It is an object of the present invention to provide an airframe structure integrated antenna capable of reducing the area and reducing the possibility of radar detection.

[0006]

According to a first aspect of the present invention, there is provided an integrated antenna having a fuselage structure having an opening formed on a part of an outer plate of the fuselage and a mounting mechanism provided inside the opening. Antenna element mounting means attached to the body outer panel through the antenna element, and the antenna element mounting means having a shape having a straight portion and not parallel or orthogonal to the arrival direction and polarization direction of the electromagnetic wave assuming the straight portion. And a radome formed of a member that transmits electromagnetic waves and that closes the opening, so that the amount of electromagnetic waves reflected in the arrival direction of the electromagnetic waves is reduced.

According to a second aspect of the present invention, the antenna element according to the first aspect has a plurality of linear portions, and the longest linear portion is not parallel or orthogonal to the assumed arrival direction and polarization direction of the electromagnetic wave. And an antenna element installed in the antenna element installation means.

[0008] A body structure integrated antenna according to a third aspect of the present invention is formed by providing a plurality of slot openings in a part of a body body plate having conductivity, and in an assumed arrival direction and polarization direction of an electromagnetic wave. A slot antenna element formed in a shape that is not parallel or perpendicular to the slot antenna element, a circuit board disposed close to the inner surface side of the slot antenna element, and held on the body outer panel via an attachment mechanism; A power supply line formed on a substrate; and power supply means for supplying power by electromagnetically coupling the power supply line to each of the slot antenna elements to reduce the amount of radio wave reflection in the direction of arrival of the electromagnetic wave. Features.

A fourth invention is the first, second or third invention.
In the antenna of the present invention, a radio wave absorber for a specific frequency is provided as a part of the antenna component.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1A is an overall view showing a state in which a radome of a body structure integrated antenna according to an embodiment of the present invention is removed, and FIG. 1B is a view showing an antenna element portion. 2 is a cross-sectional view (cross-sectional view on the xz plane) showing the basic structure. 1 and 2, an airframe skin 1 is an airframe skin structure formed of metal or the like.
It has the strength and environmental resistance as an airframe of a flying object, space equipment, etc., and plays a role in maintaining the entire structure in terms of strength. A part of the body outer panel 1, that is, a portion for mounting the antenna is opened, and a mounting frame structure 12 is provided inside the opening 11, and a substrate for forming an antenna element and a circuit is provided in the mounting frame structure 12. Installed. That is, the antenna element forming substrate (dielectric layer) 14 is laminated on the upper side (opening 11 side) of the conductor plate 13 as a center, and
A circuit forming substrate (dielectric layer) 16 is laminated on the lower side, and attached to the attachment frame structure 12.

Then, a plurality of antenna elements 15 are formed on the surface of the antenna element forming substrate 14. The antenna element 15 is formed in, for example, a rhombus shape as shown in FIG. 1B and arranged in an array. The arrival direction (incident angle) of the electromagnetic wave and its longitudinal edge and surface are assumed. It is set so as not to be parallel or orthogonal to the polarization direction. That is, the antenna element 15 is configured so that, on the xy plane shown in FIG. 1, the reflected energy is excluded from the xy plane with respect to the arrival direction of the electromagnetic wave and the polarization in the z direction. Further, the surface portion generated in the mounting frame structure 12 is configured to reflect the incident electromagnetic wave out of the arrival direction similarly to the case of the antenna element 15.

The direction of arrival of the electromagnetic wave is in front of the body in the traveling direction of the aircraft and is a shallow angle with respect to the aircraft axis, for example, when the front of the body is 0 °, the radar is present in an angle range of about ± 45 °. Although reflection is assumed, it changes depending on the mounting position of the antenna and the flight condition. The antenna element 15 may be obliquely provided, for example, in a shape other than a diamond shape, such as a rectangle.

A circuit forming board 16 provided below the conductor plate 13 is a high-frequency board, on which a high-frequency electronic circuit composed of an electronic component 17 and a microstrip line 18 is mounted. Is done. This high-frequency electronic circuit processes a desired high-frequency signal, and its feeding point is set at a circuit forming substrate 16 and an antenna element forming substrate 14.
The antenna element 15 is electromagnetically coupled to the antenna element 15 by a connection pin 19 inserted through the through hole of the conductor plate 13. The conductor plate 13 acts as a ground conductor for a high-frequency electronic circuit formed on the surface of the antenna element 15 and the circuit forming substrate 16. Further, below the electronic circuit, an electronic circuit protection case 21 for electromagnetically and mechanically protecting the electronic circuit is provided, and is mounted on the mounting frame structure 12.

On the other hand, a radome 22 for protecting the antenna portion is mounted in the opening 11. The radome 22 is formed in a shape corresponding to the body outer panel 1 by using, for example, a dielectric member, so that the radome 22 has strength and environmental resistance as the body panel, radiates from the antenna element 15, or has an antenna element 15. , So that the electromagnetic wave incident on the device is efficiently transmitted.

With the above configuration, the body outer panel 1 formed into an aerodynamically appropriate shape becomes a part of the antenna structure, so that the air resistance can be reduced and the damage caused by icing can be reduced. . Further, since the body outer panel 1 has a structure integrated with the antenna, the weight of the antenna can be reduced as compared with the case where the system is configured by individual devices.

Further, an antenna is provided inside the body outer panel 1, and the mounting frame structure 12 and the antenna element 15 are set so as not to be parallel or orthogonal to the arrival direction and the polarization direction of the electromagnetic wave. The antenna does not become a protrusion on the outer plate, and the return reflected wave in the direction of arrival of the radio wave inside the antenna structure is greatly reduced. As a result, the radar cross-sectional area is reduced and the possibility of radar detection is reduced. Can be.

Although not particularly shown in the above embodiment, a radio wave absorber for a specific frequency may be provided as a part of the antenna component. By providing the radio wave absorber in this way, it is possible to further reduce the return reflected wave in the radio wave arrival direction.

(Second Embodiment) FIG. 3 is an external structural view of an airframe structure integrated antenna according to a second embodiment of the present invention.
Is a sectional view showing a basic structure. As shown in FIGS. 3 and 4, a plurality of slot openings having a width of, for example, about half a wavelength are provided in a part of the body outer panel 1 having conductivity such as metal, that is, an antenna component, to radiate or receive electromagnetic waves. Antenna element 31 for this purpose. The slot antenna elements 31 are arranged in an array on the surface of the body outer panel 1 at regular intervals, for example, at an interval of one wavelength (λg), and are arranged with respect to an assumed arrival direction (incident angle) and polarization direction of an electromagnetic wave. , Are not parallel or orthogonal. In the example of FIG. 3, the slot antenna element 31 is configured not to be perpendicular to the z-axis direction. Although the slot antenna element 31 has been described with respect to a case where the width is set to a half wavelength and the interval is set to one wavelength as desirable values, other values may be used. The slot shape is roughly classified into a narrow slot width type and a wide slot type. Generally, as the slot width increases, the frequency characteristics thereof show a wide band characteristic.

A circuit board is mounted on the inside of the body outer panel 1 via the mounting frame structure 12 at a position corresponding to the slot antenna element 31. This circuit board is formed by stacking a circuit forming board (dielectric layer) 32 for feeding power on the upper side with the conductor plate 13 as the center, and laminating the circuit forming board 16 on the lower side. Is arranged in close proximity. The circuit forming substrate 3
On the surface of 2, a microstrip line 33 is formed as a feed line to the slot antenna element 31. In this case, the feed microstrip line 33 is positioned corresponding to each slot antenna element 31, and the microstrip line 33 excites each slot antenna element 31.

A high-frequency electronic circuit composed of an electronic component 17 and a microstrip line 18 is mounted on the surface of the circuit-forming substrate 16 to process a desired high-frequency signal. The power supply point of the high-frequency electronic circuit is electromagnetically coupled to the power supply microstrip line 33 of the slot antenna element 31 by the connection pin 19 inserted through the through holes of the circuit boards 16 and 32 and the conductor plate 13. The conductor plate 13 includes a microstrip line 33.
In addition, it acts as a ground conductor for the high-frequency electronic circuit formed on the surface of the circuit forming substrate 16.

Further, a radio wave absorber 34 is arranged in the above structure, for example, in a high frequency cavity generated at a corner between the microstrip line 33 and the body outer panel 1, so as to absorb an electromagnetic wave of a specific frequency. . Further, below the high-frequency electronic circuit, an electronic circuit protection case 21 for electromagnetically and mechanically protecting the electronic circuit is provided, and is mounted on the mounting frame structure 12.

With the above configuration, the air resistance can be reduced and the harm of icing can be reduced as in the first embodiment. Further, since the body outer panel 1 itself forms an antenna element and forms a structure integrated with the electronic circuit, the weight of the antenna can be reduced.

Furthermore, since a slot antenna element is formed on the body outer panel itself, and the slot antenna element is formed in a shape that is not parallel or orthogonal to the assumed arrival direction and polarization direction of the electromagnetic wave, return to the radio wave arrival direction is performed. The reflected wave can be greatly reduced, and the possibility of radar detection can be reduced.

Further, by providing the radio wave absorber 34 for a specific frequency as a part of the antenna component,
It is possible to further reduce the return reflected wave in the radio wave arrival direction. In the first and second embodiments, a case has been described in which a single-layer circuit forming substrate 16 is provided as a substrate for forming an electronic circuit, separately from the antenna-side substrate. Other circuits can be formed over the same substrate.

[0025]

As described above in detail, according to the present invention, in an antenna mounted on, for example, an aircraft, a flying object, a space device, etc., a part of the body outer plate is opened, and an array of An antenna is provided, and the longitudinal edge of the array antenna is set so as not to be parallel or orthogonal to the arriving direction and the polarization direction of the assumed electromagnetic wave, and the opening is formed by a radome formed of a member that transmits the electromagnetic wave. Since the portion is closed, the body outer plate itself formed into an aerodynamically appropriate shape becomes a part of the antenna structure, so that it is possible to reduce air resistance and reduce harm of icing. Further, since the body outer panel has a structure integrated with the antenna, the weight of the antenna can be reduced as compared with a case where the system is configured by individual devices. In addition, the antenna does not become a protrusion on the outer plate, and the return reflected wave in the direction of arrival of the radio wave inside the antenna structure is greatly reduced. As a result, the radar cross-sectional area is reduced and the possibility of radar detection is reduced. can do.

Further, according to the present invention, an array of slot antenna elements is formed by forming a slot opening in the body outer panel itself, and the slot antenna element is assumed to be parallel to the arrival direction and the polarization direction of the electromagnetic wave assumed. And it is not orthogonal, and an electronic circuit is arranged inside the fuselage outer plate, and the electronic circuit is configured to supply power to the slot antenna element, so that the fuselage outer plate itself forms an antenna element and forms an electronic circuit. The integrated structure makes it possible to reduce the air resistance, icing, and weight of the antenna, and to greatly reduce the return reflected wave in the radio wave arrival direction, thereby reducing the possibility of radar detection. Further, by providing a radio wave absorber for a specific frequency as a part of the antenna component, the return reflected wave in the radio wave arrival direction can be further reduced.

[Brief description of the drawings]

FIG. 1A is an overall view showing a state in which a radome of an airframe structure integrated antenna according to an embodiment of the present invention has been removed,
(B) is a diagram showing an antenna element portion.

FIG. 2 is an exemplary sectional view showing a basic structure according to the embodiment;

FIG. 3 is an external configuration diagram of an airframe structure integrated antenna according to a second embodiment of the present invention.

FIG. 4 is an exemplary sectional view showing a basic structure according to the embodiment;

FIG. 5 is a perspective view showing the configuration of an antenna mounted on a conventional aircraft or the like.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body outer plate 11 Opening 12 Mounting frame structure 13 Conductor plate 14 Antenna element formation board 15 Antenna element 16 Circuit formation board 17 Electronic component 18 Microstrip line 21 Electronic circuit protection housing 22 Radome 31 Slot antenna element 32 Circuit formation board 33 Microstrip line for power supply 34 Radio wave absorber

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takaaki Hirose 1-1-1, Koyokita-Kita, Itami-shi, Hyogo Sumitomo Electric Industries, Ltd. Itami Works (72) Inventor Toru Iwai Shimaya 1-chome, Konohana-ku, Osaka-shi, Osaka 1-3, Sumitomo Electric Industries, Ltd., Osaka Works (72) Inventor Tetsuo Kishimoto 1-3-1, Shimaya, Konohana-ku, Osaka, Osaka, Japan Sumitomo Electric Industries, Ltd. Osaka Works (72) Inventor Koichi Murakami Nagoya, Aichi Prefecture 10 Nagoya Aerospace System Works, Mitsubishi Heavy Industries, Ltd.

Claims (4)

[Claims] 1. An opening formed by opening a part of a body outer panel, antenna element installation means provided inside the opening, and mounted to the body outer panel via a mounting mechanism,
An antenna element installed in the antenna element installation means and having a shape having a linear portion and not parallel or orthogonal to the arrival direction and polarization direction of the electromagnetic wave assuming the linear portion, and a member that transmits the electromagnetic wave And a radome for closing the opening to reduce the amount of radio wave reflection in the direction of arrival of the electromagnetic wave. 2. The antenna element installation means such that the antenna element has a plurality of linear portions, and the longest linear portion is not parallel or orthogonal to an assumed arrival direction and polarization direction of an electromagnetic wave. The integrated antenna according to claim 1, wherein the antenna element is an integrated antenna element. 3. A plurality of slot openings are formed in a part of an outer body plate having conductivity, and formed in a shape which is not parallel or orthogonal to an assumed arrival direction and polarization direction of an electromagnetic wave. A slot antenna element, a circuit board disposed close to the inner surface side of the slot antenna element, and held on the body outer panel via an attachment mechanism, and a feed line formed on the circuit board. An antenna integrated with a body structure, comprising: a power supply unit that electromagnetically couples a power supply line to each of the slot antenna elements to supply electric power, so as to reduce a radio wave reflection amount in a direction of arrival of the electromagnetic wave. 4. The integrated body structure antenna according to claim 1, wherein a radio wave absorber for a specific frequency is provided as a part of the antenna component.