JPH0666120U - Tri-plate type planar antenna - Google Patents

Abstract

(57) [Summary] [Purpose] Even in higher frequency bands such as the millimeter wave band,
To provide a triplate-type planar antenna capable of maintaining a sufficiently uniform distance from a power feeding board to a ground conductor and realizing good characteristics. A triplate-type planar antenna configured by stacking a ground conductor 1, a feeding substrate 3, and a ground conductor 4 via a dielectric 2 and a dielectric 2 '. The whole is packed with a thin dielectric sheet 8.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a triplate type planar antenna used for transmission and reception in a microwave band and a millimeter wave band.

[0002]

[Prior art]

 One way to increase the antenna efficiency of a planar antenna is to use a triplate line to reduce the loss of the feed line. As shown in FIG. 4, the basic structure of this type of antenna is that a grounding conductor 1 and a power feeding substrate 3 having a power feeding line 6 and a grounding conductor 4 are laminated and arranged via a dielectric 2 and a dielectric 2 '. It is a thing. As shown in FIG. 4 (a), the structure of the radiating portion is such that the radiating element 5 is provided on the feeding substrate 3 and the slot 7 is provided in the ground conductor 4, or the radiating element 5 is radiated to the ground conductor 4 as shown in FIG. 4 (b). There is a type in which the element 5 is provided. All of the antennas of this configuration have a triplate line configuration in which the upper and lower sides of the feed line 6 are shielded by the ground conductor 4 and the ground conductor 1, so that there is no need for discontinuity of the feed line 6 such as bending or branching. Since it can suppress radiation, it is useful as a method for constructing a highly efficient planar antenna. The type shown in FIG. 4A is disclosed in Proceedings B-102 and B-103 of the 1991 Electronic Information Communication Society Spring National Convention. However, in this type of antenna, it is important to keep the distance from the feeding substrate 3 to the ground conductor 1 and the ground conductor 4 uniform, and it is necessary to consider the floating prevention of the ground conductor 4 and the like from the viewpoint of the configuration. As a method of preventing the ground conductor 4 from floating, as shown in FIG. 5 (a), it is common to hold several places of the ground conductor 4 by tightening screws, etc. As for the above, a laminate using an adhesive as shown in FIG. 5B may be considered.

[0003]

[Problems to be solved by the device]

 On the other hand, in such a triplate-type planar antenna, when an antenna having an extremely high frequency band such as a millimeter wave band is constructed, the thickness of the dielectric 2 and the dielectric 2'becomes extremely thin, and Even a slight floating of the conductor 4 will greatly affect the characteristics of the antenna. On the contrary, since the arrangement interval of the radiating elements 5 becomes smaller as the frequency rises, the physical space for forming the feed line 6 becomes stricter and the places where the screwing or the like can be performed are limited. For this reason, it is difficult to realize stable antenna characteristics by the method shown in FIG. 5 (a), and the method using the adhesive in FIG. In the wave band, all of the current adhesives have a large effect, and there are problems such as deterioration of the antenna characteristics.

The present invention provides a triplate-type planar antenna capable of maintaining a sufficiently uniform distance from a feeding substrate to a ground conductor even in a higher frequency band such as a millimeter wave band and realizing good characteristics. It is a thing.

[0005]

[Means for Solving the Problems]

 As shown in FIG. 1, the triplate type planar antenna of the present invention is configured by stacking a ground conductor 1, a power supply substrate 3, and a ground conductor 4 via a dielectric 2 and a dielectric 2 '. In the above-mentioned tri-plate type planar antenna, the whole tri-plate type planar antenna is packed with a thin dielectric sheet 8. Further, a dielectric spacer 9 may be provided between the ground conductor 4 and the dielectric sheet 8, and the pack of the dielectric sheet 8 may be a vacuum pack.

[0006]

[Action]

 Since the entire tri-plate type planar antenna is packed with the thin dielectric sheet 8, the entire surface of the ground conductor 4 can be pressed uniformly. Further, by providing a dielectric spacer 9 made of a foamed dielectric or the like having a small relative permittivity between the ground conductor 4 and the dielectric sheet 8, the distance d between the ground conductor 4 and the dielectric sheet 8 can be reduced It is possible to set the distance at which the influence of the seat 8 is the smallest. Furthermore, by making the pack of the dielectric sheet 8 into a vacuum pack, it is possible to eliminate the influence of the expansion of the air inside the pack due to the ambient temperature change thereafter. The above pack is a more suitable construction method as the antenna becomes thinner and smaller at high frequencies such as the millimeter wave band.

[0007]

【Example】

One embodiment of the present invention is shown in FIG. In the structure of the antenna, the ground conductor 1 is an aluminum plate having a thickness of 1 mm, the dielectric 2 and the dielectric 2 ′ are Teflon sheets having a thickness of 0.5 mm and a relative permittivity of about 2.1, and the power feeding substrate 3 is thick. A film substrate obtained by laminating a copper foil having a thickness of 18 μm to a polyimide film having a thickness of 25 μm was used as the ground conductor 4 using an aluminum plate having a thickness of 0.3 mm. On the feeding substrate 3, a radiating element 5 and a feeding line 6 which are square and have a side of 0.26 times the free space wavelength λ ₀ having a use frequency of 60 GHz are formed by etching. Further, a square slot 7 whose one side is 0.5 times λ ₀ is formed in a portion of the ground conductor 4 directly above the radiating element 5. The array of the radiating elements 5 and the slots 7 was a square array having a distance 0.8 times λ ₀ to form a 16-element array. A dielectric spacer 9 made of polyethylene foam having a thickness of 0.5 times λ ₀ and a relative permittivity of about 1.1 is provided on the surface of the ground conductor 4 of the 16-element array constructed as described above. The whole was packed with a dielectric sheet 8 made of a polyethylene sheet having a thickness of 100 μm to manufacture a triplate type planar antenna. Figure 3 shows the measurement results of the gain and efficiency of the manufactured antenna. The manufactured antenna showed good characteristics as an antenna in an extremely high frequency band of 60 GHz.

[0008]

[Effect of device]

 As described above, according to the present invention, it is possible to maintain a uniform distance from the power feeding board 3 to the ground conductor 1 and the ground conductor 4 even in a higher frequency band such as a millimeter wave band, which is a good antenna. It is possible to provide a triplate type planar antenna having characteristics.

[Brief description of drawings]

1A is a sectional view showing an embodiment of the present invention, and FIG. 1B is a sectional view showing another embodiment of the present invention.

2A is a partially cutaway plan view showing an embodiment of the present invention, and FIG. 2B is a sectional view of FIG. 2A.

FIG. 3 is a table showing characteristics of an embodiment of the present invention.

FIG. 4A and FIG. 4B are perspective exploded views of a conventional example.

5A and 5B are cross-sectional views showing another conventional example.

[Explanation of symbols]

1. Ground conductor 2, 2 '. Dielectric 3. Power supply board 4. Ground conductor 5. Radiating element 6. Power supply line 7. Slot 8. Dielectric sheet 9. Dielectric spacer

Claims (3)

[Scope of utility model registration request] 1. A ground conductor 1, a radiating element 5, a feed line 6 or a feed substrate 3 having only the feed line 6, and a slot 7.
Alternatively, in a tri-plate type planar antenna configured by laminating a ground conductor 4 having a radiating element 5 and a dielectric 2 and a dielectric 2 ′, the whole tri-plate type planar antenna is a thin dielectric. A triplate type planar antenna characterized by being packed by a sheet 8. 2. The triplate-type planar antenna according to claim 1, wherein a dielectric spacer 9 is provided between the ground conductor 4 and the dielectric sheet 8. 3. The triplate-type planar antenna according to claim 1, wherein the pack made of the dielectric sheet 8 is a vacuum pack.