JPH0522030A - Planar antenna - Google Patents

Abstract

PURPOSE:To obtain the planar antenna which can be easily manufactured at low cost without wasting materials while simplifying the structure and can obtain valid tapered feeding. CONSTITUTION:A patch 103 of a main antenna is composed of a metal plate and at the central part, a corn 113 is formed by pressing so as to be defined as tapered feeding. A copper foil 116a of a one-sided substrate 116 loaded on the patch is defined as the microstrip line of a sub antenna. The patch 103 and a base plate 101 are conducted by a hollow short pin 104, and feeding is executed through the hollow part to the copper foil 116a. The head part of the corn 113 is coupled to the base board 101 by a bolt nut.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar antenna.

[0002]

2. Description of the Related Art A planar antenna of this type is expected to be small in size and good in appearance when used for mobile communication such as a car telephone. In particular, with the aim of demonstrating its function in complex environments such as urban areas and mountainous areas, a ring patch antenna that is sensitive to electric fields and a notch antenna that is sensitive to magnetic fields are simultaneously configured to enable power density reception. As shown in FIG. 5 and FIG. 6, which have been announced at the National Conference of the Institute of Electronics, Information and Communication Engineers Autumn 1990.

That is, the double-sided board 11 is arranged at a distance from the conductive base plate 1, and the lower surface copper foil of the double-sided board 11 serves as the patch 3 as an element of the main antenna. The base plate 1 and the patch 3 are electrically connected by a short pin 4. This short pin constitutes a matching pin in the ring patch antenna which is the main antenna.
The ring 5 is attached to the center of the patch 3 as a simple taper for expanding the band of the main antenna.
The feed shaft 2 to the main antenna is connected to the bottom of the.

The patch 3 is, as indicated by the broken line in FIG.
The copper foil is peeled off to form a notch 6, which is a notch. This notch forms a pair with the microstrip line 7 formed of the upper surface copper foil of the double-sided substrate 11 to form a notch antenna as a sub-antenna. Electric power is supplied to the sub-antenna by the power supply shaft 8 of the connector 10 which also serves to maintain the distance between the ground plane and the patch.

The short pin 4 is embodied by using a connector. Since the outer cylinder of the connector 10 is made of non-conductive resin, a conductive tape is wound around the outer cylinder.
One end of this conductive tape is connected to the patch and the other end is connected to the base plate with silver paste, respectively, to perform a conduction function as a short pin. In FIG. 5, 9 is a power feeding connector to the main antenna, and 31 is a power feeding cable to the sub antenna connected to the connector 10.

[0006]

However, in the above planar antenna, the mechanical assembly strength of the base plate and the double-sided substrate is maintained by winding it around the resin outer cylinder by using the power feeding connector to the sub antenna. Since it is only done by connecting the patch of the conductive tape and the silver paste to the ground plane and soldering with the power supply shaft, when it is mounted on a moving object such as an automobile, which is the original aim, the conductive tape will be vibrated. May loosen or the silver paste may peel off, resulting in poor conduction and structural backlash.

Further, the power feeding portion of the main antenna is provided as a separate component on the double-sided board, which makes it difficult to form a sufficiently effective taper power feeding, and the upper surface of the double-sided board for forming the microstrip line. Since most of the copper foil is peeled off and removed, there is a problem that the processing takes a long time and the cost is increased.

Therefore, the present invention has been made in view of such conventional problems, and provides a strong planar antenna which has a simpler structure, can be manufactured easily at low cost, and can obtain effective taper feeding. The purpose is to

[0009]

For this reason, according to the present invention, a grounding plate of a conductor and a patch made of a metal plate, which is opposed to the grounding plate with a gap therebetween, are electrically connected by a short pin, and the patch is a notch. And the central part is formed into a cone shape to serve as the main antenna element,
A single-sided board was placed on the upper surface of the patch across the notch, the conductive foil of the single-sided board was used as an element of the sub-antenna, and the tip of the cone of the patch was used as the main antenna feeding point.

[0010]

Since the patch is made of a metal plate, the taper structure of the main antenna feeding portion can be easily realized by a cone formed by press molding. Furthermore, there is no need to create a sub-antenna microstrip line from a large-area double-sided board,
A single-sided substrate of a size suitable for the shape of the final product is formed without waste. Further, if the tip of the cone is connected to the base plate by screw means, the strength of the whole antenna is increased.

[0011]

1 and 2 show an embodiment of the present invention.
Reference numeral 101 is a conductive base plate, and 103 is a patch made of a metal plate which is arranged opposite to the base plate 101 with a space therebetween, and serves as an element of the main antenna. The patch 103 is the base plate 1
01 and the patch 103 are electrically connected by a short pin 104 of a tubular conductor whose both ends are soldered.
This short pin 104 is provided at four places to form a matching pin in the ring patch antenna which is the main antenna. Notch 106 in patch 103
Are formed in four directions to form notches. Further, the central portion is press-molded into a cone 113 shape.

A copper foil 11 serving as a conductive foil is provided on the patch 103.
A single-sided board 116 having 6a is arranged so as to extend across the cutout 106, and the microstrip line 117 formed by the copper foil 116a and the notch formed by the cutout make a pair to form a notch antenna as a sub-antenna.
The short pins 104 may be connected to the ground plate 101 and the patch 103 with screws instead of being soldered.

As shown in the enlarged view of FIG. 3, the microstrip line 117 is provided with a single-sided board 116 having a copper foil 116a on the upper surface of an elongated dielectric portion 116b, with the dielectric portion 116b being in contact with the patch 103. The copper foil 116a is connected to the power feed shaft 108 that penetrates the hollow portion of the short pin 104. The other end of the power feeding shaft 108 is connected to a sub antenna power feeding connector 110 protruding from the tip of the short pin 104 on the main plate side. Here, the power supply shaft 108 may omit the power supply connector 110 and directly connect the power supply line 136 to the copper foil 116a, and includes the power supply line in that case.

FIG. 4 shows the details of the main antenna feeding portion in the central portion of the patch 103. An attachment surface 114 parallel to the general surface of the patch 103 is formed at the tip of the cone 113. The patch 103 and the base plate 101 have a mounting surface 114.
An insulating spacer 121 is sandwiched between the base plate 101 and the base plate 101, and the bolts 122 and nuts 123 of the insulating member are also coupled by screw means. At this time, the core wire terminal 12 of the power feeding cable 125 is provided between the spacer 121 and the mounting surface 114.
6 is sandwiched as a power supply line to the main antenna, and the shield terminal 127 of the power supply cable is sandwiched between the spacer 121 and the base plate 101, and simultaneously tightened and crimped.

According to this embodiment, since the patch of the main antenna is formed of a single metal plate, the taper structure of the feeding portion can be easily realized by forming the cone by press molding. Further, since the central portion of the patch on which the main antenna power feeding portion is formed is firmly coupled with the power feeding line by the bolt and nut, the strength of not only the power feeding portion but also the entire antenna is surely increased. Furthermore, since the microstrip line of the sub-antenna is formed of an elongated single-sided board, most of the copper foil on one side of the double-sided board is not wasted as in the conventional case.

[0016]

As described above, according to the present invention, the patch serving as the main antenna element is made of a metal plate, and the microstrip line of the sub-antenna is formed by using an elongated single-sided substrate, which results in waste of material. Not let
The cost can be reduced, and the effective taper structure can be easily formed in the power feeding portion of the main antenna.

Further, when the feeding portion of the main antenna is connected to the ground plane by screw means, there is an advantage that the strength of the entire antenna is increased.

[Brief description of drawings]

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

FIG. 2 is a view on arrow AA in FIG.

FIG. 3 is a diagram showing details of a microstrip line in the example.

FIG. 4 is a diagram showing details of a main antenna feeding unit in the embodiment.

FIG. 5 is a diagram showing a conventional example.

6 is a view taken along the line BB in FIG.

[Explanation of symbols]

 101 Ground plate 103 Patch 104 Short pin 106 Notch 108 Feeding shaft 110 Feeding connector 113 Cone 114 Mounting surface 116 Single-sided board 116a Copper foil 116b Dielectric part 117 Microstrip line 121 Spacer 122 Bolt 123 Nut 125 Feeding cable 126 Core wire terminal 127 Shield 136 Power supply line

Claims (1)

Claim: What is claimed is: 1. A conductive base plate and a patch made of a metal plate, which is opposed to the base plate at a distance from each other, are electrically connected by a short pin, and the patch has a cutout and a central portion. The portion is formed into a cone shape to be the element of the main antenna, and the one-sided substrate is placed across the notch on the patch upper surface, and the conductive foil of the one-sided substrate is used as the sub-antenna element, and the patch is A planar antenna characterized in that the tip of the cone serves as the main antenna feeding point.