JP2005219651A - Airplane antenna and airplane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an airplane antenna hardly becoming an air resistance element as a simple substance, without icing, and capable of restraining a quantity of radio wave reflection low and an airplane using the same. <P>SOLUTION: The airplane antenna comprising a radiator 10 and an antenna plate element 20 arranged almost parallel to the radiator 10 is adopted . The radiator 10 is arranged along an airframe surface 1 of the airplane and the antenna element 20 is fixed to the radiator 10 at a position away from the airframe surface 1. When the airframe surface 1 is formed of conductive material, this airframe surface 1 can be used as the radiator 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an aircraft antenna and an aircraft.

  Conventionally, since the blade antenna provided on the aircraft is provided so as to protrude outward from the surface of the airframe, it may become a resistance element of air and cause aerodynamic characteristics of the airframe to be deteriorated. In addition, icing may occur due to flight conditions, weather conditions, and the like, which may be a factor that degrades antenna performance. Furthermore, in order not to increase the air resistance, it is necessary to reduce the cross-sectional area along the airframe surface as much as possible. Moreover, in a fighter aircraft etc., in order to make it difficult to be captured by a radar, it is required to reduce the amount of radio wave reflection (RCS: Radar Cross Section) as much as possible.

  Therefore, an antenna system in which an antenna element is built in a vertical tail of an aircraft has been proposed (Patent Document 1 below). In the same document, a flat antenna element and a flat dielectric element are arranged vertically (adjacent) along the virtual same plane in the vertical tail, and a gap (notch) is provided between them. The provided notch antenna is adopted.

Japanese Patent No. 3272646

  In the antenna system described above, it is evaluated that the antenna does not become an air resistance element by itself and that the RCS does not increase by being incorporated in a part that is already an air resistance element, such as a vertical tail, but icing is not possible. The point that the performance is reduced due to this is not solved.

  The present invention has been made in view of the above circumstances, and an antenna for an aircraft that is unlikely to be a resistance element of air alone, that is not icing, and that can keep RCS low, and an aircraft including the same. It is intended to provide.

As means for solving the above problems, an aircraft antenna having the following configuration is employed.
That is, the aircraft antenna of the present invention includes a radiator and a plate-like antenna element disposed substantially parallel to the radiator, the radiator is disposed along the aircraft body surface, and the antenna element radiates. It is characterized by being fixed at a position separated from the body surface with respect to the body.
In the present invention, the plate-like antenna element is disposed substantially parallel to the air flow along the airframe surface, so that the air resistance of the antenna element can be kept very small. In addition, since the antenna element is plate-shaped, it is easy to determine the size of the antenna element according to the frequency band of the electromagnetic wave transmitted and received, and it is easy to manufacture.

  At this time, it is preferable to arrange the radiator on the bottom surface of the recess formed on the surface of the machine body. As a result, the projecting amount of the antenna element arranged in parallel with the radiator from the surface of the airframe is reduced, so that the air resistance of the antenna element is suppressed to a low level and ice formation on the antenna element is difficult to occur.

  Furthermore, the antenna element is preferably fixed at the same level as or lower than the surface of the body around the recess. As a result, the antenna element does not protrude from the airframe surface, so that the air resistance of the antenna element can be further reduced and icing on the antenna element is further unlikely to occur.

  When the aircraft body surface is formed of a conductive material, the aircraft surface can also function as a radiator in the aircraft antenna of the present invention. In this way, it is only necessary to provide the antenna element so as to face the surface of the machine body, and the number of parts can be reduced. On the other hand, when the aircraft body surface is formed of a composite material or the like, it is necessary to install a radiator on a part of the aircraft surface.

  According to another aspect of the present invention, there is provided an aircraft including an antenna element which is spaced apart from the surface of the airframe and fixed substantially parallel to the surface of the airframe in a plane portion or a portion having a large curvature radius of the airframe surface made of a conductor. You can also In the present invention, the flat portion of the surface of the airframe or the portion with a large radius of curvature does not significantly change the unevenness on the surface of the airframe even when a plate-like antenna element is installed along the surface of the airframe. Disturbance is less likely to occur. In addition, since a large number of plane portions or portions having a large radius of curvature are found everywhere on the aircraft regardless of the type of aircraft, it is easy to find an appropriate installation location of the antenna element.

  According to the present invention, the air resistance can be suppressed to a very low level, and the aerodynamic characteristics of the airframe are not deteriorated. In addition, since the protrusion from the surface of the airframe is suppressed, icing is unlikely to occur, and it does not cause a decrease in antenna performance, and RCS can be suppressed low. Further, the use of a plate-like antenna element has an advantage that it is easy to ensure the omnidirectionality of electromagnetic waves transmitted and received.

An embodiment of the present invention will be described with reference to FIGS.
FIG. 1 shows a magnetic current forming antenna provided on a smooth airframe surface 1 of an aircraft airframe. This magnetic current forming antenna includes a radiator 10 made of a dielectric and a plate-like antenna element 20 arranged in parallel with the radiator 10. The radiator 10 has a circular shape in plan view, and is disposed on the bottom surface of the mortar-shaped recess 2 formed on the body surface 1 of the body outer plate made of a composite material. The antenna element 20 has a circular shape when viewed in the same manner as the radiator 10, and is spaced outward from the body surface 1 with respect to the radiator 10, and has the same level as the body surface 1 around the recess 2 as shown in FIG. It is arrange | positioned in this position, and is being fixed to the body by the leg part 11 which stands on the radiator 10.
When the antenna element 20 fixed to the airframe is viewed from a direction perpendicular to the airframe surface 1, the radiator 10 and the antenna element 20 are in a positional relationship in which the centers coincide with each other so as to form a concentric circle.

  The magnetic current forming antenna generates an electric field between the radiator 10 and the antenna element 20 when power is supplied to the antenna element 20 via the legs 11. Of the electric fields generated between the antenna element 20 and the antenna element 20, in particular, the antenna element 20. The electric field generated at the peripheral edge, that is, the magnetic current, contributes to the radiation of electromagnetic waves. Since the antenna characteristics of the magnetic current forming antenna vary depending on the shape and size of the radiator 10 and the antenna element 20, the distance between them, and the like, they are appropriately set according to the target frequency, band, and the like.

  In the magnetic current forming antenna configured as described above, the antenna element 20 is disposed substantially parallel to the air flow along the airframe surface 1 of the airframe outer plate, so that the air resistance of the antenna element 20 is extremely low. Can be kept small. Moreover, since the antenna element 20 is plate-shaped, it is easy to determine the size of the antenna element 20 according to the frequency band of electromagnetic waves to be transmitted and received, and it is easy to manufacture.

  In the above-described magnetic current forming antenna, the antenna element 20 arranged in parallel with the radiator 10 does not protrude from the body surface 1, so that the air resistance of the antenna element 20 can be suppressed to an extremely low level, and the antenna element 20 It is difficult for icing to occur.

  The above magnetic current forming antenna is installed on the smooth airframe surface 1, and even if the plate-like antenna element 20 is installed along this portion, the unevenness on the airframe surface 1 does not appear greatly, and the flight Disturbances are less likely to occur in the air flow inside. In addition, since a plane portion or a portion with a small curvature such as an antenna is found in many parts of the aircraft regardless of the type of aircraft, it is easy to find an appropriate installation location of the antenna element 20.

  By the way, in the present embodiment, the fuselage outer plate is made of a composite material, and the radiator 10 is arranged except for a part of the fuselage outer plate. However, when the fuselage outer plate is made of a conductor, it is positioned directly below the antenna element 20. It is also possible for the machine body outer plate to function as the radiator 10. In this case, the number of parts of the magnetic current forming antenna can be reduced, and the cost can be reduced.

In the present embodiment, the planar shape of the antenna element 20 is circular, but the shape of the antenna element 20 is not limited to this, and depending on the target frequency, band, use of the mounted aircraft, etc., Any shape such as a rectangle and a polygon can be adopted.
Further, in the present embodiment, the antenna element 20 is arranged at the same level as the airframe surface 1 around the recess 2, but the height of the antenna element 20 is not limited to this and is lower than the airframe surface 1 around. It may be at a level, or conversely, it may be at a level higher than the surrounding airframe surface 1. However, if it is fixed at a level higher than the airframe surface 1, the air resistance increases and the possibility of icing increases, which is not preferable.

Modified examples of the present embodiment are shown in FIGS.
In the modification of FIG. 3, a spherical radome 3 that covers the entire area of the recess 2 and accommodates the entire antenna element 20 is provided. Since the antenna element 20 is plate-shaped, the air resistance can be kept very small, but the air resistance cannot be eliminated at all. Therefore, by providing the radome 3 as described above, air does not collide with the antenna element 20 and the air resistance can be further reduced.
If the radome 3 is provided in this way, there is no problem even if the antenna element 20 is arranged at a higher level than the surrounding body surface 1.

  In the modification of FIG. 4, a resin material 4 having a characteristic that does not inhibit the generation of an electric field is filled between the radiator 10 and the antenna element 20. Only the upper surface of the antenna element 20 is exposed, the periphery thereof is smoothed, and the airframe surface 1 is formed smoothly without unevenness even if it includes the antenna element 20. In this way, air does not collide with the antenna element 20 in the same manner as described above, and air resistance can be further reduced.

  In the modification of FIG. 5, the recess 2 is not provided on the body surface 1, and the antenna element 20 is fixed so as to protrude from the body surface 1. A spherical radome 5 that houses all the antenna elements 20 inside is provided. In this way, the air resistance of the antenna element 20 can be reduced without providing the recess 2. However, the radome 5 rises greatly, and the air resistance of the radome 5 itself increases. Therefore, the air resistance cannot be reduced as much as the other examples.

It is a figure which shows embodiment of this invention, Comprising: It is the figure which looked at the magnetic current formation type | mold antenna provided in the body surface. FIG. 2 is a cross-sectional view of the magnetic current forming antenna of FIG. 1 including the airframe. It is a figure which shows the modification of the magnetic current formation type | mold antenna shown in FIG. 1, FIG. 2, Comprising: It is the figure which looked at the antenna including the airframe in cross section. Similarly, it is a figure which shows the other modification of a magnetic current formation type | mold antenna, Comprising: It is the figure which looked at the antenna including the airframe in cross section. Similarly, it is a figure which shows the other modification of a magnetic current formation type | mold antenna, Comprising: It is the figure which looked at the antenna including the airframe in cross section.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Airframe surface, 2 ... Concave part, 3, 5 ... Radome, 4 ... Resin material, 10 ... Radiator, 20 ... Antenna element

Claims (5)

A radiator, and a plate-like antenna element disposed substantially parallel to the radiator,
An aircraft antenna, wherein the radiator is disposed along a surface of an aircraft body, and the antenna element is fixed at a position spaced from the surface of the aircraft with respect to the radiator.   The aircraft antenna according to claim 1, wherein the radiator is disposed on a bottom surface of a recess formed on a surface of the body.   3. The aircraft antenna according to claim 2, wherein the antenna element is fixed at a level equal to or lower than the surface of the body around the recess.   The aircraft antenna according to any one of claims 1 to 3, wherein the airframe surface is formed of a conductive material, and the airframe surface functions as the radiator.   An aircraft comprising an antenna element, which is spaced apart from the surface of the airframe and fixed substantially parallel to the surface of the airframe, on a plane portion of the surface of the airframe made of a conductor or a portion having a large radius of curvature.

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