JP3026203B2 - Antenna device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device capable of radiating an elliptical beam based on a microstrip antenna.

[0002]

2. Description of the Related Art Conventionally, an elliptical horn antenna has been used as a primary radiator for radiating an elliptical beam. An elliptical horn antenna A3 shown in FIG.
This is a structure for inputting and outputting coaxially via a coaxial waveguide converter 32. A coaxial connector 33 is connected to the coaxial waveguide converter 32.

[0003]

However, in such an elliptical horn antenna A3 as described above,
The size of the antenna is large, especially the depth is long, and the antenna is heavy and inconvenient to handle. Further, since the input and output ends of the antenna are waveguides, the coaxial waveguide converter 32 is required when the latter stage is a coaxial system.

[0004] Therefore, there has been a demand for an antenna capable of emitting an elliptical beam that is small, easy to handle, and has good compatibility with a coaxial cable.

[0005]

In order to solve the above problems SUMMARY OF THE INVENTION, the antenna device according to claim 1, one surface of a circular substrate beam emitting surface, the microstrip antenna with a ground plane on the other hand, the circular substrate A conductive waveguide that rises cylindrically from the periphery on the ground plane side to the beam emission surface side, and conducts between the waveguide and the ground plane of the microstrip antenna, and the cylindrical waveguide body is a circular substrate. The width of the emitted beam is changed by changing the amount of protrusion rising from the periphery in the circumferential direction of the waveguide, thereby obtaining an elliptical beam.

According to a second aspect of the present invention, there is provided an antenna device according to the first aspect, wherein the circular substrate of the microstrip antenna is a perfect circle.

According to a third aspect of the present invention, there is provided an antenna device according to the first aspect, wherein the circular substrate of the microstrip antenna has an elliptical shape having a major axis and a minor axis in a circumferential direction.

[0008] The principle by which an elliptical beam can be radiated by adopting the structure of the present invention will be described below.

An antenna having a structure in which a cup is attached to a microstrip antenna (Japanese Patent Application No. 9-59954, filed on Feb. 27, 1997,
(Title of Invention: Antenna device) has been proposed. The structure of the microstrip antenna with a cup is as shown in FIG. 7, and a substrate 43 (microstrip antenna element) on which a microstrip patch 41 having a feed point 42 is formed is substantially formed of a conductive member. An antenna device A4 in which a cylindrical cup member 44 is provided, the cup member 44 is grounded on the ground surface of the microstrip antenna element, and power is supplied by a coaxial connector 46. By changing the beam width, the beam width and the gain can be appropriately changed.

The characteristics of the antenna device A4 having the above-described cup member 44 are as shown in FIG.
That is, the diameter of the cup member 44 is constant (diameter = λ: λ
When the height H of the cup member 44 is changed, the width of the beam emitted changes with the change in the height. When the height is approximately λ / 3, the beam width is minimized. become.

Further, as shown in FIG. 9, it is known that when the diameter of the cup member 44 is increased, the beam width is reduced. In addition, the beam width of the vertical axis | shaft in FIG. 9 sets the diameter of each cup member 44 to each value (3/4 (lambda)-5/4 (lambda)),
This is the minimum beam width when the beam width on the H plane is minimized by changing the height of the cup member 44 of each diameter. That is, the above-described antenna device 4A in which the substrate 43 is a perfect circle and the cup member 44 has a constant height cannot emit an elliptical beam, but the height of the cup member 44 is changed in the circumferential direction, or the diameter of the substrate 43 is changed in the circumferential direction. If the angle is changed (the elliptical shape in which the major axis and the minor axis are generated), an elliptical beam can be radiated by the antenna device configured based on the microstrip antenna.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of an antenna device according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an antenna device A according to a first embodiment, in which a microstrip patch 1 is connected to a feeding point 2.
The shape of the circular substrate 3 affixed with the symbol is a perfect circle, the surface on which the microstrip patch 1 fed by the coaxial connector 6 is a beam emitting surface, and the other surface on which the ground plate 7 is affixed is a ground surface. And a cup member 4 serving as a conductive waveguide that rises in a cylindrical shape from the periphery of the circular substrate 3 toward the beam radiation surface.
To electrically connect the waveguide 4 to the ground plate 7.

The protrusion amount (height) of the cup member 4 is
The maximum is λ / 3 and the minimum is zero. That is, the height of the cup member 4 on the beam cut surface (the surface including the X axis) where the beam width is to be reduced is set to λ / 3, and the beam cut surface (the surface including the Y axis) where the beam width is desired to be widened is set. If the height of the cup member 4 on the surface is changed in the circumferential direction so as to become zero, the height of the cup member 4 becomes λ / 3.
An elliptical beam having a narrow beam width on the surface and a wide beam width on the surface where the height of the cup member 4 is zero can be emitted.

[0015] indicates to the antenna device A1 in FIG. 2, there the shape of a circular substrate 13 microstrip patch 11 is affixed with a feeding point 12 as ellipses, the coaxial connector 1
The microstrip antenna, to which the surface on which the microstrip patch 11 fed by 6 is attached becomes a beam emitting surface and the other surface on which the ground plate 17 is attached becomes a grounding surface, has a cylindrical shape from the periphery of the circular substrate 13 to the beam emitting surface side. A cup member 14 as a conductive waveguide that rises in a shape is provided,
The waveguide 14 and the ground plate 17 are electrically connected. In this antenna device A1 , the cup member 14
Has a uniform height in the circumferential direction, a large diameter in the horizontal direction (horizontal direction in FIG. 2), and a small diameter in the vertical direction (vertical direction in FIG. 2). The resulting elliptical cylinder.

FIG. 3 shows an antenna device A2 according to a second embodiment. A circular substrate 23 to which a microstrip patch 21 is attached with a feeding point 22 has an elliptical shape and is fed by a coaxial connector 26. The surface on which the microstrip patch 21 is adhered becomes a beam radiation surface, and the other surface on which the ground plate 27 is adhered becomes a ground plane, and rises in a cylindrical shape from the periphery of the circular substrate 23 toward the beam radiation surface. A cup member 24 as a conductive waveguide is provided, and the waveguide 24 and the ground plate 27 are conducted.

In this embodiment, the maximum amount of protrusion of the cup member 24 is λ / 3 and the minimum is zero, and the elliptical shape has a large diameter in the horizontal direction and a small diameter in the vertical direction. is there. That is, the antenna device A2 according to the second embodiment is a combination of the antenna device A according to the first embodiment and the above-described antenna device A1.

FIG. 4 shows a state in which the protruding shapes of the cup members 4 and 24 in the first embodiment and the second embodiment are developed on a plane. The height of the cup member 4 is in the circumferential direction φ
, And φ = 0 °, 180
The angle is set to λ / 3 (maximum protrusion), φ = 90 ° and zero (minimum protrusion) at 270 °.

FIG. 5 shows a characteristic diagram of a prototype of the above-described antenna device A of the first embodiment and measurement of a radiation beam. In the drawing, the pattern on the φ = 0 degree plane is a radiation pattern on a plane cut on the XZ plane, and is a so-called H plane pattern. On the other hand, the pattern on the φ = 90 ° plane is a pattern cut on the YZ plane, and is an E-plane pattern.

The following table summarizes the beam width based on the measurement results. For reference, the beam width when there is no cup in the same microstrip antenna is also shown. 10d with a cup compared to without a cup
It can be seen that the difference in B width is large and the ellipticity is large.

[0021]

[Table 1]

The substrate 3 used for the microstrip antenna in the prototype antenna device A has a relative dielectric constant of 2.17 and a thickness of 1.6 m. The diameter of the microstrip patch 1 is 46 mm. The operating frequency of the microstrip antenna is 2.5 GHz. Also,
The polarization was linearly polarized, and power was supplied to the microstrip antenna at one point on the Y-axis with a pin from the back. The cup member 4 was formed by attaching a copper tape having a thickness of about 0.1 mm to a cardboard, and the copper tape portion was grounded to the ground plate of the microstrip antenna. The diameter of the cup is 150 mm (1.25λ).

If the antenna device is used as a primary radiator of an elliptical parabolic reflector antenna, the aperture efficiency of the elliptical parabolic reflector antenna can be maximized.
It is suitable for such applications.

[0024]

As described above, claims 1 to 1 are described.
According to the antenna device of the third aspect , since the elliptical beam can be radiated using the microstrip antenna which is a planar antenna, the depth of the antenna can be reduced and the weight can be reduced as compared with the case where the horn antenna is used for radiating the elliptical beam. Can be achieved. Moreover, in the present antenna device, it is possible to reduce the size of the antenna device as a whole in a state where it is attached. Therefore, it is possible to provide an antenna device with extremely high convenience in handling and the like.

Further, since the microstrip antenna is used for the antenna device, there is a feature that compatibility with coaxial is good.

[Brief description of the drawings]

FIG. 1A is an external perspective view of an antenna device according to a first embodiment. FIG. 2B is a plan view of the antenna device according to the first embodiment. (C) It is an II vertical sectional view of the antenna device concerning a 1st embodiment.

FIG. 2 (a) A cup member is provided on an elliptical circular substrate.
It is an external appearance perspective view of the antenna device which was set. (B) A plan view of the antenna device in which a cup member is provided on an elliptical circular substrate . (C) It is II-II longitudinal sectional view of the antenna apparatus which provided the cup member in the elliptical circular substrate .

FIG. 3A is an external perspective view of an antenna device according to a second embodiment. (B) It is a top view of the antenna device concerning a 2nd embodiment. (C) III-II of the antenna device according to the second embodiment
It is I longitudinal section.

FIG. 4 is a developed plan view of a cup member in the antenna devices according to the first embodiment and the second embodiment.

FIG. 5 is a characteristic diagram illustrating an antenna pattern of the antenna device according to the first embodiment.

FIG. 6 is an external perspective view of a conventional elliptical horn antenna.

FIG. 7A is an external perspective view of a conventional antenna device. (B) It is a top view of the conventional antenna device. (C) It is a VII-VII longitudinal sectional view of the conventional antenna device.

8 is a characteristic diagram showing a change in beam width with respect to the height of a cup member in the conventional antenna device shown in FIG.

9 is a characteristic diagram showing a change in a beam width with respect to a diameter of a cup member in the conventional antenna device shown in FIG.

[Explanation of symbols]

 A antenna device 1 microstrip patch 2 feeding point 3 substrate 4 cup member 6 coaxial connector 7 ground plate

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01Q 13/00-13/28 H01Q 15/00-15/24 H01Q 17/00 H01Q 19/00-19 / 32

Claims (3)

(57) [Claims] 1. A microstrip antenna in which one surface of a circular substrate is a beam radiating surface and the other surface is a grounding surface, a conductive member which rises cylindrically from the periphery of the circular substrate on the grounding surface side to the beam radiating surface side. provided sexual waveguides, is made conductive and the ground plane of the conductor waves body and the microstrip antenna, the protrusion amount of the cylindrical waveguide rises from a circular substrate by changing the circumferential direction of the waveguide An antenna device wherein an emitted beam width is changed to obtain an elliptical beam. 2. The antenna device according to claim 1, wherein the circular substrate of the microstrip antenna is a perfect circle. 3. The antenna device according to claim 1, wherein the circular substrate of the microstrip antenna has an elliptical shape having a major axis and a minor axis in a circumferential direction.