JPH11289218A - Planar antenna - Google Patents

Abstract

(57) [Summary] To obtain a high-performance and inexpensive directional planar antenna. SOLUTION: A ground conductor is formed on a front surface of a double-sided printed wiring board, and a power supply conductor pattern is formed on a back surface. A microstrip antenna using a dielectric substrate is mounted on the surface of the wiring board, and a power supply point is connected to an end of a power supply pattern of the wiring board. A metal plate is arranged on the power supply pattern side of the wiring board at an interval to form a reflector, and female screws are attached to the metal plate so that the antenna can be fixed to a tripod for a camera.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar antenna used in a high frequency range of 1 GHz to 6 MHz, and more particularly to a structure of an antenna having directivity.

[0002]

2. Description of the Related Art Advances in communication technology have increased the demand for antennas that can handle high frequencies and have good directivity in the field of antennas. In general, the object is achieved by forming a plurality of antenna elements on a dielectric substrate, synthesizing signals received from the antenna elements, and branching a signal to be transmitted. In addition, a similar configuration is often adopted to cope with horizontal polarization or vertical polarization.

[0003] Since a dielectric substrate used for an antenna is required to have a predetermined dielectric constant and a high Q, the material is expensive. When a plurality of antenna elements are formed on a single substrate, it is necessary to use the same material for a portion that does not operate as an antenna, which not only increases the cost but also produces a homogeneous dielectric substrate. Is also difficult. Further, it is necessary to form a radiation electrode on one surface of the dielectric substrate, form a ground electrode on the opposite surface, and form a strip conductor for power supply between them. Accordingly, the design of the power supply pattern is likely to be restricted, and the mismatch is likely to occur. When a mismatch occurs, the radiation from the radiation pattern is superimposed on the radiation from the radiation pattern, and the characteristics change.

Further, when a plurality of antenna elements are formed on a single substrate, the size of the entire antenna becomes large. For this purpose, the end of a metal fitting or the like attached to the back of the antenna is fastened to a pole or the like. Or it needs to be fixed by a method such as screwing to the wall. There are structural restrictions depending on the mounting position, and it may be difficult to adjust the installation direction of the directional antenna.

[0005]

SUMMARY OF THE INVENTION According to the present invention, directivity can be obtained with a plurality of antenna elements using inexpensive materials, there is no restriction on the design of a feed pattern, design is easy, and impedance matching is easy. A simple planar antenna is provided. It is another object of the present invention to provide a planar antenna having stable characteristics by suppressing unnecessary radiation. Further, the present invention provides a planar antenna that can be installed in an arbitrary direction at an arbitrary position without being restricted by an installation position and an installation direction, and easily obtains a desired directivity.

[0006]

According to the present invention, a dielectric microstrip antenna is mounted on a two-layer printed circuit board.
Further, a metal plate provided with a female screw is arranged on the back surface to solve the above problem.

That is, a feed pattern of a conductor extending from a coaxial feed point to a feed point of a plurality of antenna elements on one surface is defined as:
A power supply substrate having a conductor ground pattern on the opposing surface, a radiation electrode on the surface of the dielectric substrate, and a ground electrode on the back surface, the ground electrode is connected to the ground pattern of the power supply substrate, and the power supply point of the radiation electrode is a power supply substrate A plurality of antenna elements connected to the end of the power supply pattern and mounted on the power supply substrate, a metal plate disposed at a position facing the power supply pattern of the power supply substrate at an interval, and attached to the metal plate to the outside It is characterized by having an internal thread that opens.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A commonly used double-sided printed circuit board is used as a power supply substrate. A ground pattern is formed on the side on which an antenna element is mounted, and a conductor pattern for power supply is formed in a predetermined shape and size on the opposite surface. The power supply conductor pattern is formed by branching halfway from a power supply point connected to the coaxial cable and extending to a position corresponding to the power supply point of each antenna element. The antenna element is mounted and connected to the feed electrode.

A metal plate also serving as a shield is arranged facing the power supply conductor pattern. This metal plate may be formed as a part of a case so as to have a U-shaped cross section, and a plastic or other radome may be placed on the upper side via a rubber material or the like. A female screw opening on the outer surface is attached to the metal plate, and a male screw of a camera platform tripod head can be screwed onto the female screw and fixed and installed.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing an embodiment of the present invention. For the sake of explanation, a state where the radome is not covered is shown. A conductor pattern for grounding is formed on almost the entire surface of the printed wiring board 11. Although not shown, a power supply conductor pattern is formed on the back surface of the printed wiring board 11.

On the surface of the printed wiring board 11, four microstrip antennas 13 are mounted. The microstrip antenna 13 has a radiation electrode on the surface of the dielectric substrate, and a ground electrode on almost the entire back surface. The conductor pattern for grounding of the printed wiring board 11 and the ground electrode of the microstrip antenna 13 are connected by soldering or the like, and the microstrip antenna 13
Is mounted on the printed wiring board 11. The power supply point 12 of the microstrip antenna 13 and the end of the power supply conductor pattern of the printed wiring board 11 are connected to the power supply terminal via a through hole or the like.

The printed wiring board 11 is fixed to the metal plate 15 by screws or the like. The metal plate 15 is formed in a dish shape, for example, having a circular shape, the periphery of which is raised vertically. In this example, a female screw 19 opening on the outer peripheral surface is fixed to the metal plate 15. The printed wiring board 11 has a coaxial line 17
Are fixed, the inner conductor is connected to the conductor pattern for power supply on the back surface, and the outer conductor is connected to the conductor pattern for grounding.

FIG. 2 is a front view showing a state where the radome is covered. A plastic radome 20 is attached to the tip of the raised portion around the metal plate 15 via rubber packing or the like. When used outdoors, a radome is required for drip-proofing, but is not always required when used only indoors.

FIG. 3 is a perspective view showing an example of the mounting structure of the planar antenna according to the present invention. The planar antenna 30 is attached to a tripod by screwing a male screw of a camera platform 36 of a camera tripod 34 to a female screw portion. The radiation direction can be arbitrarily set by the camera platform 36, and the position can be moved as needed. A flat antenna can be installed on walls, rooftops, etc., including poles, railings, etc., in combination with metal fittings equipped with external threads. There is no restriction on the installation location in the exhibition hall or laboratory.

When assembling the planar antenna according to the present invention, the characteristics of the individual microstrip antennas can be measured or tested so as to be adjusted to predetermined characteristics before assembly. Individual antenna elements can also be adjusted independently. Further, the directional characteristics can be changed by changing the distance between the antenna elements.

The metal plate disposed opposite to the printed wiring board becomes a part of the case, and also acts as a reflection plate that also serves as a shield for unnecessary radiation generated by the mismatch of the power supply pattern of the printed wiring board. It does not affect the radiation characteristics from the pattern.

[0018]

According to the present invention, the parts other than the antenna element can be completed with an inexpensive double-sided printed circuit board, the cost of the planar antenna can be greatly reduced, and the size of the power supply pattern is small and the size is small. Can be realized. In addition, since the characteristics of the microstrip antenna can be inspected, measured, adjusted, and then mounted on a printed circuit board, it is easy to assemble the planar antenna as designed, and the number of adjustment steps after assembly is unnecessary. Since the power supply conductor pattern of the printed circuit board is sandwiched between the metal plate and the ground conductor, unnecessary radiation can be prevented, and a planar antenna with stable characteristics can be obtained.

[0019] Furthermore, with a simple structure in which the female screw is fixed to the metal plate, the female screw can be fixed only by screwing it into the male screw, and the installation place is less restricted. In addition, it is easy to attach the camera to a movable support such as a tripod for a camera, and it is also easy to install the camera while adjusting the direction so as to maximize the directivity.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a front view showing an embodiment of the present invention.

FIG. 3 is a perspective view showing another embodiment of the present invention.

[Explanation of symbols]

 30: Planar antenna 11: Printed wiring board 13: Microstrip antenna 34: Tripod 15: Metal plate 36: Head 17, 37: Coaxial line 19: Female screw 20: Radome

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01Q 21/06 H01Q 21/06

Claims (3)

[Claims] 1. A power supply pattern extending from a coaxial line power supply point to a power supply point of a plurality of antenna elements on one surface, a power supply substrate having a conductor ground pattern on an opposite surface, a radiation electrode on a surface of a dielectric substrate, Equipped with a ground electrode on the back, the ground electrode is connected to the ground pattern of the power supply board,
A plurality of antenna elements mounted on the power supply board with the power supply point of the radiation electrode connected to the end of the power supply pattern on the power supply board; a metal plate disposed at a position facing the power supply pattern on the power supply board at an interval; A planar antenna with a female screw attached to a metal plate and opening outward. 2. A feeder pattern of a conductor extending from a coaxial feeder to a feeder of a plurality of antenna elements on one surface, a feeder substrate provided with a grounding pattern of the conductor on an opposite surface, a radiation electrode on a surface of the dielectric substrate, Equipped with a ground electrode on the back, the ground electrode is connected to the ground pattern of the power supply board,
A plurality of antenna elements mounted on the power supply board with the power supply point of the radiation electrode connected to the end of the power supply pattern on the power supply board; a metal plate disposed at a position facing the power supply pattern on the power supply board at an interval; A planar antenna comprising a female screw attached to a metal plate and opening outward, and a radome attached to the metal plate and covering the antenna element and the power supply board. 3. The planar antenna according to claim 1, wherein the female screw is screwable with a male screw of a tripod head for a camera.