JPH07170120A - Planar antenna - Google Patents

Abstract

PURPOSE:To obtain a planar antenna with simple configuration in which a reception characteristic with a high efficiency at a board band is obtained. CONSTITUTION:A ground conductor 10 and a feeding board 14 on which a feeding lien 16 is formed are provided by inserting a 1st dielectric sheet 12 inbetween. A radiation board 20 are provided on the feeding board 14 by inserting a 2nd dielectric sheet 18 inbetween. Circular openings 24 formed in a matrix state and radiation patches each 26 formed in each opening 24 are provided on a metallic thin film 22 on an insulation film 21. Each radiation patch 26 is constituted of a straight line part 28 located in parallel with the feeding line 16 and having a width narrower slightly than that of the feeding line 16 and a couple of curved parts 30 formed from both ends of the straight line part 28 in the same turning direction along the circumferential ridge of the opening 24 at a predetermined interval in which a virtual line linking the tips is orthogonal to the straight line part 26. The curved parts 30 are formed relatively widely at both ends of the straight line part 28 and have a shape to be converged while being curved toward each tip.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat antenna for receiving radio waves from satellites such as broadcasting satellites.

[0002]

2. Description of the Related Art Conventionally, a plane antenna is disclosed in Japanese Patent Laid-Open No. 63-2.
As disclosed in Japanese Patent Laid-Open No. 58104, a grounding conductor and a power feeding substrate on which a power feeding line is formed are provided with a dielectric sheet sandwiched therebetween, and another radiation sheet is sandwiched with respect to this power feeding substrate. Is provided on the radiation substrate,
An annular slot formed by etching an aluminum foil or the like on the film and arranged in a matrix, and a radiation patch made of the aluminum foil in the annular slot are provided. The shape of the annular slot is provided as an inner portion of the rectangular opening, and the outer peripheral portion is formed in a rectangular shape. The radiation patch is formed by being surrounded by the annular slot, and is formed in a rectangular shape, a circular shape, or the like. Further, as disclosed in Japanese Patent Application Laid-Open No. 4-133505, there has been proposed one in which this radiation substrate is formed of a two-layer metal plate having an aperture.

[0003]

However, in the case of the above-mentioned conventional technique, it cannot be said that the efficiency in receiving the circularly polarized radio wave is good, and the reception band is relatively narrow.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a planar antenna having a simple structure and capable of obtaining highly efficient reception characteristics in a wide band.

[0005]

According to the present invention, a ground conductor and a power feeding substrate on which a power feeding line is formed are provided with a first dielectric sheet interposed therebetween, and a second dielectric material is provided with respect to the power feeding substrate. A radiation substrate is provided with a sheet sandwiched therebetween, and the radiation substrate is provided with circular openings formed in a matrix on a metal thin film on an insulating film and radiation patches formed in the openings. The patch is formed in parallel with the power supply line and has a slightly narrower width than the power supply line, and is formed at predetermined intervals along the periphery of the opening in the same rotation direction from both ends of the straight line part. An imaginary line connecting the ends of the straight parts is composed of a pair of curved parts that are orthogonal to the straight parts, and the curved parts are formed relatively wide at both ends of the straight parts, and bend toward the ends. Converged A planar antenna having a Jo. Further, the present invention uses the radiation patch as a first radiation patch, and between the radiation substrate and the second dielectric sheet,
A second radiation board and a third dielectric sheet are laminated, and on this second radiation board, a second radiation patch having substantially the same shape as the above-mentioned first radiation patch made of a metal thin film is formed on an insulating film. It was done. Further, the second radiation patch is formed to face each other with a shape slightly smaller than that of the first radiation patch.

[0006]

The planar antenna of the present invention receives circularly polarized radio waves in a wide band with high efficiency by a plurality of radiating patches having a pair of curved portions formed in a circular opening, and feeds each of the feeding lines and electromagnetic fields. The electromagnetic waves are coupled to each other and collect radio waves in the same phase via each power supply line.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment of the present invention. A planar antenna of this embodiment is a ground conductor 10 made of a metal plate such as an aluminum plate or a copper plate, and a foamed polyethylene sheet having a thickness of about 2 mm. First dielectric sheet 12 by etc.
have. Furthermore, PE is added to the dielectric sheet 12.
Power supply line 1 using T-film and metal foil such as aluminum foil
The power supply boards 14 on which 6 are formed are stacked. The power supply line 16 of the power supply board 14 is formed by etching the metal thin film into a predetermined pattern. further,
A second dielectric sheet 18 similar to the first dielectric sheet 12 is stacked on the power supply board 14, and the radiation board 20 is stacked on the power supply board 14 with the second dielectric sheet 18 interposed therebetween.

The radiation substrate 20 is provided with a metal thin film 22 such as an aluminum foil on an insulating film 21 such as a PET film. The metal thin film 22 has a circular opening 24 which is hollowed out by etching. Are formed in a large number. The opening 24 has a diameter of about ½ of the wavelength of the received radio wave, and a radiation patch 26 having a maximum width slightly narrower than the inner diameter of the opening 24 is provided inside the opening 24. The maximum width of this radiation patch 26 and the opening 2
It is advisable to adjust the intermediate length between the inner diameter of 4 and the inner diameter of 4 to be half the wavelength of the radio wave in the reception band. The radiation patch 26 is formed by leaving the metal thin film 22 in a predetermined shape during etching.

As shown in FIG. 3, the radiation patch 26 is arranged in parallel with the power feeding line 16 and has a power feeding line 26.
A straight line portion 28 having a slightly narrower width and an imaginary line connecting the ends of the straight line portion 28 are linearly formed at predetermined intervals along the peripheral edge of the opening 24 in the same rotation direction from each other. It is composed of a pair of curved portions 30 orthogonal to the portion 28. The planar antenna of this embodiment is for right-handed circularly polarized wave reception, and the curved portion 30 extends clockwise in the drawing. The curved portion 30 is relatively wide at both ends of the straight portion 28, and has a shape that converges while curving toward the tip. Then, the peripheral portion of the opening 24 formed in the radiation substrate 20 and the portion without the metal thin film 22 between the radiation patch 26 form an annular slot 29.

The planar antenna of this embodiment is based on the radiation substrate 2
Radio waves from the satellite are received by the respective radiating patches 26 of 0, electromagnetically coupled with the corresponding power supply lines 16, and the received radio waves are collected at the power supply points (not shown) in the same phase via the respective power supply lines 16. It is a thing.

Next, a second embodiment of the present invention will be described with reference to FIG.
A description will be given based on FIG. Here, the same members as those in the above-described embodiment are designated by the same reference numerals, and the description thereof will be omitted. The planar antenna of this embodiment is the second dielectric 1 having the structure of the first embodiment.
8, a second radiation substrate 40 on which a radiation patch 36 as shown in FIG. 5 is formed is laminated, and a third dielectric sheet 42 is placed on the second radiation substrate 40, and the same as in the first embodiment. The radiation substrate 20 is laminated. The radiation patch 36 is formed in the same manner as the radiation patch 26 of the radiation substrate 20, but is not formed in the opening 24 like the radiation patch 26, but on the insulating film 21 such as PET. The metal thin film 22 such as an aluminum foil provided on the substrate is etched to leave only the radiation patch 36. The maximum width of the radiation patch 36 is slightly smaller than the maximum width of the radiation patch 26.
If the radiation patch 36 has a width of 2 mm, the reception characteristic will be improved by forming the radiation patch 36 with a width of 11 mm.

According to the planar antenna of this embodiment, it is possible to perform reception with better characteristics than the above embodiments.

The plane antenna according to the present invention is constructed by reversing the shape of the radiation patch of the above embodiment,
It serves as an antenna for receiving left-handed polarized waves.
Further, the radiation patch of this planar antenna is not limited to the above-mentioned embodiment, and can be used not only for the microstrip power feeding type but also for, for example, a suspended power feeding type antenna as a power feeding method. Further, the shape of the curved portion of the radiation patch can be appropriately modified. In addition to the metal foil, the metal thin film may be a thin film formed by depositing a metal on the surface of an insulator, or a thin metal plate attached.

[0014]

The flat antenna of the present invention has a simple structure, can efficiently receive circularly polarized radio waves, and has a wide reception band. Further, the radiation substrate can be easily formed, and a flat antenna having excellent characteristics can be provided at low cost.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a planar antenna according to a first embodiment of the present invention.

FIG. 2 is a partial vertical cross-sectional view of the planar antenna of this embodiment.

FIG. 3 is a partial plan view of a radiation board of the planar antenna of this embodiment.

FIG. 4 is a partial vertical cross-sectional view of a planar antenna according to a second embodiment of the present invention.

FIG. 5 is a partial plan view of a second radiation substrate of the planar antenna of this embodiment.

[Explanation of symbols]

 10 Ground Conductor 12 First Dielectric Sheet 14 Feeding Substrate 16 Feeding Line 18 Second Dielectric Sheet 20 Radiating Substrate 21 Insulating Film 22 Metal Thin Film 24 Openings 26, 36 Radiating Patch 28 Straight Section 29 Annular Slot 30 Curved Section

Claims (3)

[Claims] 1. A ground conductor and a power feeding substrate on which a power feeding line is formed are provided with a first dielectric sheet sandwiched therebetween, and a radiation substrate is provided with a second dielectric sheet sandwiched with respect to this power feeding substrate. The radiation substrate is provided with circular openings formed in a matrix on the metal thin film on the insulating film,
A radiation patch formed in the opening is provided, and the radiation patch is located in parallel with the feed line and has a width slightly narrower than that of the feed line. A line formed along the peripheral edge of the opening at a predetermined interval and connecting the tip portions is composed of a pair of curved portions that are orthogonal to the linear portion, and the curved portions are relatively wide at both ends of the linear portion. A planar antenna, which is formed and has a convergent shape while curving toward the tip. 2. The radiation patch is used as a first radiation patch, a second radiation substrate and a third dielectric sheet are laminated between the radiation substrate and a second dielectric sheet, and the second radiation substrate and the second dielectric sheet are laminated. 2. The planar antenna according to claim 1, wherein the radiation substrate has a second radiation patch formed of a metal thin film and having substantially the same shape as the first radiation patch on an insulating film. 3. The planar antenna according to claim 2, wherein the second radiating patch is formed to have a shape slightly smaller than that of the first radiating patch and face each other.