JP3206016B2 - Planar antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

[0001] The present invention relates to a planar antenna suitable for use in a quasi-millimeter wave band such as satellite broadcasting and satellite communication.

[0002]

2. Description of the Related Art As is well known, various planar antennas have recently been put into practical use with the start of satellite broadcasting. In particular, in satellite broadcasting, with the improvement of transmission power and the improvement of the noise figure (NF) of the BS converter connected to the receiving antenna, the size and performance of the planar antenna have been improved.

[0003] Among such small planar antennas, there is a radial line slot antenna using a radial waveguide having a small transmission loss. FIG. 3 is a perspective sectional view showing the structure of the radial line slot antenna. In this figure, reference numeral 1 denotes a frame constituting the rear side of the antenna. The frame 1 is formed of a metal conductor, has a circular shape when viewed from the front, and has a flat container shape with a wide open upper portion. Reference numeral 2 denotes a slot plate on which a slot array formed by etching or the like on a metal disk is provided. Reference numeral 3 denotes a low-foam dielectric filled between the frame 1 and the slot plate 2. Here, the slot plate 2 and the frame 1 constitute a radial waveguide 4. Assuming that the dielectric constant of the low-foam dielectric 3 interposed in the radial waveguide 4 is ε, the guide wavelength λg of the transmission wave in the radial waveguide 4 is 1 / √
It is shortened by ε. For this reason, this low foam dielectric 3 is called a slow wave circuit.

[0004] Reference numeral 5 denotes a radome having a hermetically sealed structure in which the joint with the peripheral edge of the frame 1 is sealed with a silicon-based adhesive having high resistance to high and low temperatures in order to be adapted for outdoor use while covering the front of the antenna. It is. The space between the radome 5 and the slot plate 2 is filled with a spacer 6 made of a high foaming material having a dielectric constant substantially equal to that of air, whereby the slot plate 2 is brought into close contact with the low foaming dielectric 3, and
The electrical performance is stabilized by keeping the distance from the frame 1 constant. Reference numeral 7 denotes a rubber ring for protecting the outer periphery provided to cover the joint between the frame 1 and the radome 5.
The rubber ring 7 for protecting the outer periphery is used to protect the antenna from impact or the like during transportation or construction. Reference numeral 8 denotes a power supply unit, and reference numeral 9 denotes a BS converter that converts satellite broadcast waves supplied from the power supply unit into a UHF band.

Next, FIG. 4 is a cross-sectional view showing an example of a joint portion between the frame 1 and the radome 5 described above. In this figure, parts corresponding to those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted. As shown in this figure, the periphery of the frame 1 has a shape that is folded back into a U-shape with respect to the opening surface, and the edge of the radome 5 is further bent at the portion that is folded back into the U-shape. It is formed to be joined. Thereby, the frame 1 and the radome 5 are in close contact. Also,
FIG. 5 is a cross-sectional view showing another joining example. In this case, the periphery of the frame 1 is bent inward with a predetermined curvature with respect to the opening surface, while the edge of the radome 5 is formed so as to abut on the outer periphery of the radome 1 so as to overlap therewith. The radome 5 is in close contact.

The joint between the frame 1 and the radome 5 having such a structure is sealed with a silicone-based adhesive as described above. This sealing operation is performed in an antenna assembling process using the jig shown in FIG. In this figure, 20 is a turntable, 2
Reference numeral 1 denotes a presser. The holding tool 21 is a frame 1 that is arranged to face the radome 5 placed on the turntable 20.
Press. The air cylinder 22 applies a pressing force generated by the supplied compressed air to the presser 21. D1, D
Reference numeral 2 denotes a dispenser. The dispenser D1 is filled with a silicone resin, and the dispenser D2 is filled with a hot melt resin.

In order to seal the joint between the frame 1 and the radome 5 by using such a jig, first, the antenna in a temporarily assembled state is arranged on the turntable 20, and
This is pressed with a uniform pressure by the presser 21. Then, while rotating the turntable 20, a dispenser D is provided at a predetermined position of the joint between the frame 1 and the radome 5.
Using 2, hot melt resin is injected and temporarily fixed. Then, using the dispenser D1, the frame 1 and the radome 5
Silicon resin is injected over the entire circumference of the joint.
After these operations are completed, the assembly is removed from the jig and left for 24 hours to cure the resin. After the resin is cured, the outer peripheral protection rubber ring 7 is mounted and fixed with an adhesive to complete the assembly. I do.

The silicone resin injected into the joint between the frame 1 and the radome 5 has a high elasticity even when cured, so that it has an adhesive function and is formed of the radome 5 made of resin and metal. It also plays a role in absorbing a difference in expansion and contraction caused by a difference in thermal expansion coefficient from the frame 1.

[0009]

In the above-described conventional radial line slot antenna, FIG.
As shown in FIG. 6 and FIG. 6, since the edge of the radome 5 and the peripheral edge of the frame 1 are in close contact, the injection needles (outer diameter 2 mmφ) of the above-described dispensers D1 and D2 are inserted into this joint. Therefore, it has been difficult to inject silicon resin. That is, it is necessary to uniformly inject this silicone resin over the entire circumference of the joint between the frame 1 and the radome 5, but in practice only a small amount of silicone resin can be injected. It depends on the location. For this reason, the expansion / contraction difference based on the difference in the expansion coefficient between the radome 5 of the dielectric plate and the frame 1 of the metal plate cannot be absorbed.
There is also a concern that a crack may be generated in the frame 1 or the frame 1 and the radome 5 may be separated. The present invention has been made in view of the above circumstances, and has as its object to provide a planar antenna that can easily perform a sealing operation at a joint between a frame 1 and a radome 5.

[0010]

According to the present invention, there is provided a circular frame having an opening at an upper portion, and a radome which covers an opening surface of the frame and forms a circular flat space therein. in the planar antenna peripheral ring is mounted on the junction of the radome, overhanging the periphery of the radome to the outer peripheral side, set only a predetermined gap to the junction, to the gap, the bonding between the frame and radome It is characterized in that the portion is sealed and filled with a silicone resin to be adhered.

[0011]

According to the present invention, the peripheral edge of the radome is joined to the outer periphery of the radome at the joint between the circular frame having an open top and the radome which covers the opening surface of the frame and forms a circular flat space therein. A predetermined gap is provided at the joint by projecting to the side. As a result, the sealing operation performed at the joint between the frame and the radome is facilitated. Further, since the gap is uniformly filled with the silicone resin, the radome and the frame can be securely bonded together, and the difference in expansion and contraction caused by the difference in the thermal expansion coefficient between the dielectric plate and the metal plate can be surely reduced. Can be absorbed.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. A. First Embodiment FIG. 1 is a sectional view showing a structure of a first embodiment according to the present invention. In this figure, parts corresponding to the respective parts in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted. This drawing is different from the structure shown in FIG.
And a space SB into which the aforementioned silicone resin is injected and a space SB into which the injection needle of the dispenser D1 is inserted at the time of this injection.

That is, a curling portion C having an arc-shaped cross section and having a predetermined radius of curvature from the opening surface is formed on the peripheral edge of the frame 1. On the other hand, the periphery of the radome 5 is formed so as to be in close contact with the curling portion C, and the edge is formed so as to protrude in the outer peripheral direction in order to provide the space SA described above. According to such a structure, the radome 5 and the frame 1 are positioned by the curling portion C, so that the radome 5 and the frame 1 can be easily joined. Further, at the time of the sealing operation in the above-described assembling process, the dispenser D1,
The injection needle of D2 can be inserted, and the provision of the space SA allows the hot melt resin to be applied to a predetermined portion at the time of temporary fixing, and the silicone resin serving as a sealing agent is coated with this antenna. It can be injected so as to have a uniform coating thickness over the entire circumference.

B. Second Embodiment Next, FIG. 2 is a sectional view showing the structure of a second embodiment according to the present invention. In this figure, parts corresponding to the respective parts in FIG. 5 are denoted by the same reference numerals, and description thereof will be omitted. This drawing differs from the structure shown in FIG. 5 in that at the joint between the frame 1 and the radome 5, a space SA into which the silicone resin is injected and a space SB into which the injection needle of the dispenser D1 is inserted at the time of this injection. In that the cross-sectional structure is provided.

That is, the curling portion C having a predetermined radius of curvature and warping inward of the opening surface is provided on the peripheral edge of the frame 1.
Are formed. On the other hand, the periphery of the radome 5 is formed so as to be in close contact with the curling portion C, and the edge is formed so as to protrude in the outer peripheral direction in order to provide the space SA described above. According to such a structure, the curling portion C allows the radome 5 and the frame 1
By performing the positioning with respect to the above, these joinings are facilitated. In addition, during the sealing operation, the space S
In addition, the injection needles of the dispensers D1 and D2 can be easily inserted into B, and the provision of the space SA allows hot melt resin to be applied to a predetermined location during temporary fixing. It becomes possible to inject the silicone resin with a uniform coating thickness over the entire circumference.

[0016]

As described above, according to the present invention, a joint between a circular frame having an open upper portion and a radome which forms a circular flat space inside by closing the open surface of the frame. In addition, since the peripheral edge of the radome is protruded to the outer peripheral side and a predetermined gap is provided at the joint, the sealing operation performed at the joint between the frame and the radome can be easily performed. In the gap,
Since the silicon resin is uniformly filled, the radome and the frame can be securely bonded, and the difference in expansion and contraction caused by the difference in the coefficient of thermal expansion between the dielectric plate and the metal plate can be reliably absorbed.

[Brief description of the drawings]

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

FIG. 2 is a sectional view showing the structure of a second embodiment according to the present invention.

FIG. 3 is a perspective sectional view showing a structural example of a radial line slot antenna which is a conventional planar antenna.

FIG. 4 is a cross-sectional view illustrating a conventional example.

FIG. 5 is a cross-sectional view illustrating a conventional example.

FIG. 6 is a diagram for explaining a conventional example.

[Explanation of symbols]

 1 ... frame, 5 ... radome, SA, SB ... space.

Continuation of the front page (72) Inventor Masanori Suzuki 1-5-1, Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. (72) Inventor Tatsuhiro Okano 1-5-1, Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. (56) References JP-A 1-172711 (JP, U) JP-A 60-189106 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01Q 1/42 H01Q 1 / 02

Claims (1)

(57) [Claims] 1. A circular frame having an open upper portion and a radome which covers an opening surface of the frame and forms a circular flat space therein, and an outer peripheral ring is formed at a joint between the frame and the radome. dense but the planar antenna formed by attached, overhanging the periphery of the radome to the outer peripheral side, only setting a predetermined gap to the junction, the gap, the joint between the frame and radome
Make sure that the silicone resin that closes and adheres is filled
Features a planar antenna.