JPH0946119A - Radome - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve power resistance by inserting a core material between an outer skin and an inner skin and making a tip of the core material exposed to concentrated antenna transmission power with a material with excellent thermal conductivity. SOLUTION: In the radome 2 provided around the outer side of a transmission antenna 1 and whose core material 5 is inserted between an outer skin 4 and an inner skin 3, a tip of the core material onto which transmission power of the antenna 1 is concentrated is made of the core material 6 with excellent thermal conductivity. When a radio wave sent from the transmission antenna 1 passes through an inner skin material 3 of the radome 2, the core material 5, the core material 6 with excellent thermal conductivity and an outer skin material 4, each radome component material is heated. The heat generated at the tip of the inner skin material 3 is delivered to the outer skin material 4 while a heat generation area is expanded by the core material 6 with excellent thermal conductivity and cooled by natural convection or the like with the heat generated in the outer skin material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radome that protects a transmitting antenna from wind and rain, and more particularly to a radome having improved power resistance performance.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view showing a conventional radome shown, for example, in "Basics of Explanatory Antenna (Tokyo Denki University Press), page 217". In the figure, 1 is a transmitting antenna, and 2 is a radome provided outside the transmitting antenna 1 in order to protect the transmitting antenna 1 from wind and rain.

Next, the operation will be described. A radio wave transmitted from the transmitting antenna 1 passes through a radome 2 provided outside the transmitting antenna 1 and is radiated to a space. When the radio wave passes through the radome 2, the dielectric material unique to the dielectric material of the radome 2 is transmitted. A power transmission loss proportional to the tangent (tan δ) is generated in the radome 2 and causes the radome 2 to generate heat.

Since the radome 2 protects the transmitting antenna 1 from wind and rain, it must have sufficient mechanical strength to withstand it. To increase the mechanical strength, for example, if the thickness of the radome 2 is increased, the radome 2 will be electrically increased.
The transmission power is limited because the power loss becomes large and heat is generated. As described above, the radome 2 having sufficient mechanical strength and high heat resistance has been required.

[0005]

Since the conventional radome is constructed as described above, in a radome that is often made of a dielectric material, there is a limit to the heat resistance performance peculiar to the material. If the maximum transmission power of the transmitted radio waves is not limited, there is a problem that the radome cannot withstand the required radiated power and is deformed or discolored. This phenomenon is prominent in the inside of the radome where it is difficult for heat to escape because the outside is easily cooled by natural convection and wind.

The present invention has been made to solve the above problems, and provides a radome capable of relaxing the limitation of the maximum transmission power of radio waves to be transmitted, that is, a radome having improved power resistance performance. With the goal.

[0007]

The radome according to claim 1 is
It is provided on the outer circumference of the antenna and has a core material sandwiched between an outer skin and an inner skin. The tip of the core material where the transmission power of the antenna is concentrated is made of a core material with good thermal conductivity. And

According to a second aspect of the invention, the radome is provided on the outer circumference of the antenna, and the core material is sandwiched between the outer skin and the inner skin. It is characterized by being composed of a material with less

The radome according to claim 3 is provided on the outer circumference of the antenna and has a core material sandwiched between an outer skin and an inner skin. The metal wire is provided in a direction orthogonal to the direction of the electric field (polarized wave).

The radome according to claim 4 is provided on the outer periphery of the antenna and has a core material sandwiched between an outer skin and an inner skin, wherein the inner skin and the core material at the tip end where the transmission power of the antenna is concentrated are cut off. It is characterized by having a different configuration.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1. Embodiment 1 of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a transmitting antenna, 3 is an inner skin material (inner skin) of the radome 2, 4 is an outer skin material (outer skin) of the radome 2, and 5 is for fixing them to obtain the strength of the entire radome 2. The core material (normally, a honeycomb material using paper, a foaming agent or the like is used) 6 is provided in the central portion of the radome 2 and is a core material having good thermal conductivity. As the core material having good thermal conductivity, for example, Fluoroloy H manufactured by Fluorocarbon Corporation is used.

Next, the operation will be described. The radio wave transmitted from the transmitting antenna 1 passes through the inner skin material 3 of the radome 2, the core material 5, the core material 6 having good thermal conductivity, and the outer skin material 4 of the radome 2, and is transmitted to the space.
Then, the dielectric loss tangent (tan) unique to each radome material
A power transmission loss proportional to δ) occurs, causing each radome material to generate heat. Usually, the skin materials 3 and 4 of the radome 2 are often made of a substance having a large dielectric loss tangent, and the core material 5 is often made of a substance having a small dielectric loss tangent (a skin material having a large dielectric loss tangent in order to obtain both electrical performance and strength). To have a sandwich structure with a honeycomb material to make it thinner and increase its strength). Further, the transmission power from the transmission antenna 1 is most concentrated on the front surface of the antenna (the tip of the radome). That is, the skin material 3 inside the radome 2 and the radome 2
The radome tip portion of the outer skin material 4 generates the largest amount of heat.

The heat generated at the tip of the skin material 3 on the inside of the radome 2 is transmitted to the skin material 4 on the outside of the radome 2 while expanding the heat generation area by the core material 6 having good thermal conductivity, and the skin on the outside of the radome 2 is formed. It is cooled by natural convection, wind, etc. together with the heat generated by the material 4.

According to this embodiment, by using the material 6 having good thermal conductivity as the core material in the vicinity of the tip of the radome 2 where the electric power is most concentrated and the most heat is generated, the heat generated inside the radome 2 is distributed to the surroundings. It is possible to efficiently dissipate heat to the radome or the space and improve the heat resistance (power resistance) performance of the radome as a whole.

Embodiment 2 In the above-described embodiment, the power withstanding performance of the radome 2 is improved by using a material having good thermal conductivity as the core material near the tip of the radome 2 where the power is most concentrated and the most heat is generated. By using a core material (honeycomb material) having a small transmission loss instead of the above, even if the amount of heat generated near the tip of the radome 2 is reduced, the power resistance performance of the radome as a whole can be improved.

Embodiment 3 Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. In FIG. 2, reference numerals 1 to 5
Is the same as in FIG. Reference numeral 7 denotes a metal wire such as copper having excellent thermal conductivity, which is arranged in a skin material 3 inside the center of the radome 2 in a grid shape in a direction orthogonal to the direction (polarized wave) of the electric field of transmitted radio waves.

The metal wire 7 expands the heat generation area, and the heat generated at the tip portion of the skin material 3 inside the radome 2 is conducted to the portion other than the tip portion by the metal wire 7 and escaped.

According to this embodiment, the heat generated at the tip portion of the skin material 3 inside the radome 2 is dissipated to the other portion by the metal wire 7 and is efficiently dissipated.
The withstand voltage performance of the radome as a whole can be improved.

Embodiment 4 Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 3, the tip portions of the skin material 3 and the core material 5 on the inside of the radome 2 where transmission power is concentrated are cut off to leave only the skin material 4 on the outside of the radome 2.

By cutting out a portion where transmission power is concentrated and easily generates heat and is difficult to cool, heat generated can be reduced and the power withstanding performance of the entire radome can be improved.

[0021]

According to the radome of the first aspect of the present invention, the radome is provided on the outer periphery of the antenna and the core material is sandwiched between the outer skin and the inner skin, and the tip portion of the core material where the transmission power of the antenna is concentrated is thermally conducted. Since it is made of a core material having good properties, it has an effect of improving the power-proof performance of the radome.

According to a second aspect of the present invention, the radome is provided on the outer circumference of the antenna and has a core material sandwiched between an outer skin and an inner skin. Since it is made of a material that has a low content, it has the effect of improving the power durability of the radome.

The radome according to claim 3 is provided on the outer circumference of the antenna and has a core material sandwiched between an outer skin and an inner skin. Since the metal wire is provided in the direction orthogonal to the direction of the electric field (polarized wave), it has an effect of improving the power withstanding performance of the radome.

The radome according to claim 4 is provided on the outer circumference of the antenna and has a core material sandwiched between an outer skin and an inner skin, wherein the inner skin and the core material at the tip end where the transmission power of the antenna is concentrated are cut off. With this configuration, it has the effect of improving the power withstanding capability of the radome.

[Brief description of drawings]

FIG. 1 is a sectional view of a radome according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a radome according to a third embodiment of the present invention.

FIG. 3 is a sectional view of a radome according to a fourth embodiment of the present invention.

FIG. 4 is a sectional view of a conventional radome.

[Explanation of symbols]

1 antenna, 2 radome, 3 inner skin material (inner skin), 4 outer skin material (outer skin), 5 core material, 6 core material with good thermal conductivity, 7
Metal wire.

Claims (4)

[Claims] 1. In a radome provided on the outer periphery of an antenna and having a core material sandwiched by an outer skin and an inner skin, a core of the core material having a good thermal conductivity is provided at a tip portion of the antenna where transmission power of the antenna is concentrated. A radome made of materials. 2. In a radome provided on the outer circumference of an antenna and having a core material sandwiched between an outer skin and an inner skin, a material having a small transmission loss of radio waves at a tip portion of the core material where transmission power of the antenna is concentrated. A radome characterized by being composed of. 3. In a radome provided on the outer circumference of an antenna and having a core material sandwiched by an outer skin and an inner skin, a direction of an electric field of a transmission radio wave is directed to a tip portion of the inner skin where transmission power of the antenna is concentrated. A radome provided with a metal wire in a direction orthogonal to (polarized wave). 4. A radome provided on the outer periphery of an antenna, wherein a core material is sandwiched between an outer skin and an inner skin, wherein the inner skin and the core material at the tip end where the transmission power of the antenna is concentrated are cut off. A radome that is characterized by