JPS604310A - Antenna device - Google Patents

Abstract

PURPOSE:To make working and assembling easy to obtain an airtight structure economically by providing a gas charging hole in one of a shield plate, a main reflective mirror, and a radome in an antenna device of millimeter wave and submillimeter wave bands. CONSTITUTION:In a Cassegrain antenna consisting of a main reflective mirror 1, an auxiliary reflective mirror 2, a primary radiator 3, a shield plate 4, a radome 5, and a pole brace 6, an airtight structure is given to the internal space surrounded with the main reflective mirror 1, the shield plate 4, and the radome 5, and a gas charging hole 10 is provided in a part of the shield plate 4. Thus, it is unnecessary to attach a feedome, and working is made easier in comparison with the case where the charging hole is provided in a feeding waveguide 7, and dew condensation and rust on the inside are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in aperture antennas such as parabolic antennas, Cassegrain antennas, and offset antennas used in millimeter wave band and submillimeter radio relay lines.

Hereinafter, in order to simplify the explanation, a detailed explanation will be given using an example of a Cassegrain antenna.

Conventionally, this Yuzu Cassegrain antenna (hereinafter referred to as 1. antenna), which is used in sub-millimeter waves and microphone mouthwave bands with longer wavelengths, has a main reflecting mirror as shown in Figure 1 (a), ω). (
11. It consists of a sub-reflector (2), a -order radiator (31, a shield plate (411), a radome (5; is emitted from the primary radiator (3), reflected by the sub-reflector (21) and the main reflector (lt) and radiated into space via the radome (5) as shown by dotted lines and arrows. 41 is not attached depending on the antenna, and is attached to the main reflector (1
In some cases, a 1-dome (5) is attached directly to the peripheral end of 1.

In such antennas, the -order radiator (3) and feeding waveguide (7) often have a tracheal structure to prevent electrical condensation and rust from forming inside and increasing transmission loss. There is. That is, the individual waveguides constituting the feeding waveguide (7) and the -order radiator (31) are all connected airtight using a caskerat (8). , and in the opening of the primary radiator (31, as shown in Fig. 2, a feedome (9) is airtightly installed using a gasket (81, etc.) to guide the power supply.
7) is provided with a gas filling port a1, through which dry air or inert gas is sealed to prevent dew condensation and rust.

However, since the wavelength of the operating frequency is short in IJW band and submillimeter wave band antennas, the cross-sectional dimensions of the waveguide and the aperture diameter of the primary radiator (3) range from several 11 m to several 10 m, resulting in the above-mentioned problems. It becomes difficult to obtain the structure. In other words, first of all, since the waste filling port 01 is provided in the guide pipe, it is difficult to make a minute hole commensurate with the pipe diameter, which has little effect on the transmission characteristics. Because it is small, the amount of air flowing in is too small.

Also, it was very inconvenient that it was difficult to install the base of the filling port. Furthermore, the field (9) at the opening of the -order radiator (3) is also made very thin in order to reduce reflection, making it difficult to maintain airtightness.

This invention has been made to eliminate such drawbacks, and will be described below with reference to FIG. 3 showing an embodiment of the invention. In FIG.

(Old 21 tal +41 ff1) +61 (71
is similar to that in FIG.

In this antenna, there is no need for the -order radiator (3), the aperture field (9), the main reflector (1), and the shield.

The plate (41) and the radome (5) are connected and configured so that the interior thereof surrounded by each plate is airtight.

The secondary radiator (3) and support column (61) are also attached to the main reflector (1) to maintain airtightness, and the gas filling port OI is provided on a part of the shield plate (41). .

In addition, to ensure airtightness, a gasket (8
), a rubber sheet, etc. may also be used, or 'IJing material may be used from the outside of the antenna, which has no effect on drowsiness. In addition, the gas filling port O1 may be installed in a shield plate (not limited to 41, but may be installed in a part of the main reflector +11), or in a radome with a thin base like a tire tube with high flexibility. It may be attached to a part of (5).

When the antenna is configured in this way, it is necessary to provide a gas filling port (II') in the thin waveguide and to airtightly install an extremely thin feedome (9) to the opening of the -order radiator (3). By attaching a standard-sized gas filling cap to an appropriate position on the shield plate (4), main reflector (1), and radome (5) where there is sufficient space, processing and assembly are easy. Can be easily and economically made into an airtight structure,
It is clear that advantages such as no loss in electrical characteristics can be obtained.

It is clear that what has been described as a gas filling port in one or more of the spellings may also be used as a gas outlet if a filling port is provided separately. Further, although the structure or type of the antenna has been explained using the example of a case-clean antenna, the purpose of the present invention is not limited to this, and the invention is not limited to this. antenna,
Furthermore, it is obvious that the present invention can be similarly applied to aperture antennas such as an offset Cassette antenna and an offset Gregorian antenna.

As explained above, according to the present invention, an antenna used in the millimeter band or submillimeter wave band is provided.

Main reflection @ (11, shield plate (4) and radome (
The internal volume surrounded by 5) is also relatively small.

Since airtightness can be achieved easily and economically, and the electrical properties of soil are not impaired in any way, the practical effects are extremely large.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a Cassegrain antenna conventionally used in the quasi-mi') wave band and microwave bands with longer wavelengths.
Fig. 2 is a cross-sectional view showing the airtight structure of the primary radiator used in a conventional Cassegrain antenna, Fig. 3 is a cross-sectional view showing an embodiment of the antenna device according to the present invention, and Fig. 4 is the same. FIG. 3 is a sectional view showing another embodiment of the antenna device according to the invention, in which (1) is a main reflector, (2) is a sub-reflector, (31 is a primary radiator, (4) is a shield plate, and (5) is a Radome, (6) is the pillar, (7) is the feeding waveguide, (8)
indicates the gasket (91if feed dome, QIU gas filling port. In each figure, the same or corresponding parts are indicated by the same reference numerals. -Japan - Figure 1 (λ) (b) Figure 2 Figure 3 Figure 4 (i)

Claims (1)

[Claims] An antenna device used in +II'J12M and submillimeter waves, comprising a main reflector, one or more sub-reflectors, a -order radiator, a shield plate, and a radome,
The electrons radiated by the secondary radiator are reflected in the order of the sub-reflector and the main reflector, and then go into space through the radome provided in front of the main reflector via the shield plate. Place it so that it radiates. The main reflecting mirror is configured such that an interior surrounded by the main reflecting mirror, the shield plate, and the radome is kept airtight. An antenna device characterized in that either the shield plate or the radome is provided with a waste filling port or a gas outlet. (2) An antenna device used in the millimeter wave band and submillimeter wave band consists of a main reflector, a -order radiator, a shield plate, and a radome, and the radio waves radiated from the -order radiator are reflected by the main reflector. and further arranged so that the radiation is emitted into space through the radome provided in front of the main reflecting mirror via the shield plate, and the upper reflecting mirror;
The interior surrounded by the shield plate and the radome VC is configured to be airtight, and a gas filling port or a gas outlet is provided in any one of the main reflecting mirror, the shield plate, and the radome. An antenna device characterized by: