JPH08307143A - Plate shaped inverted-f antenna - Google Patents

Abstract

PURPOSE: To realize the plate shape inverted-F antenna offering excellent manufacturing performance by designing components of the plate shape inverted-F antenna as units. CONSTITUTION: A radiation conductor plate 1 and a ground conductor plate 2 are connected by a 1st metallic material 3 and power is fed to an air gap formed between the radiation conductor plate 1 and the ground conductor plate 2 and the plate shape inverted-F antenna is formed together with a feeding coaxial line 5. The plate shape inverted-F antenna is connected electrically to a metal-made case 11 by metal-made machine screws 7. Thus, the antenna section is removed easily from the case 11 by removing the metal-made screws 7, the connection of an outer conductor of the feeding coaxial line 5 to the metal-made case is not required and the plate shape inverted-F antenna with excellent manufacturing performance is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate-shaped inverted F antenna used in mobile radios or small radios.

[0002]

2. Description of the Related Art In recent years, demand for mobile communication such as mobile phones has been increasing. The conventional mobile radio antenna will be described below with reference to FIG. In FIG. 4, 1 is a radiating conductor plate which is an antenna surface, 2 is a grounding conductor plate which is a ground plane, 5 is a coaxial line for feeding power, 8 is a coaxial line center conductor, 9 is a coaxial line outer conductor, and 11 is a metal casing. Reference numeral 15 is a through hole for electrically connecting the radiation conductor plate 1 and the ground conductor plate 2 to each other, and 16 is a dielectric filled between the radiation conductor plate 1 and the ground conductor plate 2.
The radiation conductor plate 1 that is the antenna surface, the ground conductor plate 2 that is the ground plate, and the dielectric 16 are composed of printed-circuit boards on both sides. One surface is the antenna surface, and the other surface is the ground board.
Through-holes 15 electrically connect the corners of the radiation conductor plate 1 to the ground conductor plate 2. Then, the entire conductor surface of the ground conductor plate 2 is brought into contact with one surface of the metal casing 11 and connected by soldering or the like. In addition, power is fed through the coaxial line 5, the coaxial line center conductor 8 is connected to the radiation conductor plate 1, and the coaxial line outer conductor 9 is connected to the metal casing 11 or the ground conductor plate 2. The antenna as described above is generally a plate-shaped inverted F
It is called an antenna and is disclosed in JP-A-58-104504. Further, in the plate-shaped inverted F antenna, it is difficult to connect the feeder line and ground the radiation conductor plate to the metal casing in manufacturing, but Japanese Patent Laid-Open No. 6-3 has dealt with such a problem.
It can be found in Japanese Patent No. 03163 and Japanese Patent Laid-Open No. 7-46027.

[0003]

However, in the above-mentioned conventional structure, when assembling the antenna part, it is necessary to solder the grounding conductor plate to the metal casing to connect it, which is a troublesome work. It was Further, even if the antenna part is broken after the antenna part is manufactured, it is not easy to remove only the antenna part, so that the metal housing must be replaced.

Further, soldering is performed to connect the outer conductor of the coaxial line for supplying power to the metal casing. However, since the metal casing has a large heat dissipation surface, soldering is difficult to attach and the outer conductor of the coaxial line is connected. Hateful.

When the plate-shaped inverted F antenna is used at a relatively low frequency such as 400 MHz band, the impedance becomes very high, and a trimmer capacitor or the like is used to adjust the impedance matching. It was very difficult to connect the trimmer capacitor between the plates because there was not much space to arrange it.

The present invention solves the above problems and facilitates the process of attaching a radiation conductor plate, which is an antenna surface, in a factory, and the antenna section can be easily attached to and detached from a metal housing with a single metal screw. In order to realize a plate-shaped inverted F antenna that eliminates the soldering connection of the outer conductor of the feeding coaxial line to the metal housing, and has a matching circuit on the antenna surface and can adjust the impedance matching on the antenna surface. It is intended for.

[0007]

In order to achieve the above-mentioned object, the present invention fixes a radiation conductor plate which is an antenna surface and a ground conductor plate which is a ground plate through a metal material with a metal screw or the like and electrically. Connect, power is supplied between the radiation conductor plate and the ground conductor plate by a coaxial line, and a connector for connecting to the antenna connection part of the radio device is arranged on the other side of the coaxial line, excluding the metal casing. Other components of the plate-shaped inverted F antenna are assembled into a unit in advance, and the ground conductor plate is connected to the metal case by a detachable means such as a metal screw.

Further, the outer conductor of the coaxial line for feeding power is connected to the ground conductor plate.

Further, the matching circuit portion is provided on the radiation conductor plate which is the antenna surface.

Furthermore, a capacitor is arranged in the matching circuit section, and power is supplied through the capacitor.

[0011]

According to the present invention, the plate-shaped inverted F antenna portion excluding the metal casing can be attached / detached by connecting or disconnecting the ground conductor plate and the metal casing with a metal screw or the like according to the above configuration.

Also, it is possible to eliminate the work of soldering the outer conductor of the power feeding coaxial line to the metal casing.

Further, by providing the matching circuit section on the antenna surface, the impedance matching of the antenna can be adjusted only by the antenna section.

Furthermore, a plate-shaped inverted F antenna unit can be constructed by impedance matching even at a relatively low frequency such as 400 MHz band.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. The description of the same components as the conventional ones will be omitted. In FIG. 1, 3 is a metal material for electrically connecting the radiating conductor plate 1 and the grounding conductor plate 2, 4 is a matching circuit section in which a matching element for impedance matching of the antenna is arranged, and 6 is an antenna surface for impedance matching. A certain radiation conductor plate 1
And a capacitance interposed between one end of the coaxial line 5 and a metal screw 7 for electrically connecting the ground conductor plate 2 which is a ground plate and the metal casing 8 to each other. It is a metal connector for connecting to an antenna connector. In the present embodiment, the radiating conductor plate 1 which is the antenna surface is grounded to the grounding conductor plate 2 which is the ground plate in the metal material 3 which is a cylindrical rod made of brass. The radiation conductor plate 1, the ground conductor plate 2, and the metal material 3 were connected by a metal screw (made of brass) 7. The coaxial outer conductor 9 has a hole formed in the grounding conductor plate 2 and the coaxial line 5 is passed through the hole, and is connected to the grounding conductor plate 2 which is smaller than the metal casing by soldering. Similarly, the coaxial line center conductor 8 is also passed through the radiation conductor plate 1 by making a hole, and is connected to the capacitor 6 by soldering. The coaxial line 5 is arranged vertically to the radiation conductor plate 1 and the ground conductor plate 2. The radiation conductor plate 1 is used by drawing a pattern of an antenna on a metal surface using a single-sided printed circuit board made of glass epoxy resin. Similarly, the ground conductor plate 2 is also formed by using a printed circuit board made of glass epoxy resin. The pattern on the antenna surface is shown in FIG. In FIG. 3, 12 is a cutout portion of the radiation conductor plate which is the antenna surface, 13 is a metal material connecting portion to which the metal material 3 is connected, and 14 is a power feeding portion connecting portion to which one end of the power feeding portion 5 is connected.

This antenna is adjusted so as to resonate at a frequency f = 430 MHz, and the outer dimension of the antenna surface is 7
0 × 70 (mm), length of notch part l = 21 mm, w
= 3 mm. Further, the matching circuit portion was formed in a part of the periphery on the antenna surface with 10 × 3 (mm). A 3 pF chip capacitor is used for the matching circuit unit, and is connected between one end of the power supply line 5 and the radiation conductor plate 1 to adjust impedance matching.

A plate-shaped inverted F antenna unit is formed by feeding power between the radiation conductor plate 1 and the ground conductor plate 2 thus formed. The plate-shaped inverted F antenna unit having this configuration is connected to the metal housing 11 by the metal screw (made of brass) 7 to operate as a plate-shaped inverted F antenna. A cross-sectional view of the connected configuration is shown in FIG. The ground conductor plate 2 is arranged on the metal casing 11, and the metal screw (made of brass) 7 is used to electrically connect the ground conductor plate 2 and the metal casing 11. Further, a metal connector 10 is attached to one side of the power feeding coaxial line 5, and the metal connector 10 is connected to an antenna connector of a wireless device.

Although air is present between the radiation conductor plate 1 and the ground conductor plate 2 in this embodiment, one side is used as the radiation conductor plate and the other side is used as the ground conductor plate by using printed boards on both sides. If the structure is such that a dielectric is interposed, the outer dimensions of the radiation conductor plate 1 can be reduced, and the metal material 3 can be formed as a through hole.

According to the above structure, the radiation conductor plate 1 and the ground conductor plate 2 are connected by the metal material 3, and the power supply line 5 is used.
Since the antenna unit is unitized in the state where the is connected, it is possible to attach and detach the antenna unit of the plate-shaped inverted F antenna and the metal casing 8.

The outer conductor of the feeding coaxial line is a metal casing 11
Instead of connecting to the ground conductor plate 2, soldering during manufacturing becomes easier.

The radiation conductor plate 1 is formed of a printed circuit board or the like, and the matching circuit section 4 is provided on the radiation conductor plate 1 which is the antenna surface.
The radiation conductor plate 1 in which the impedance matching of the plate-shaped inverted F antenna is the antenna surface by providing
You will be able to align above.

[0022]

As is apparent from the above description, when the plate-shaped inverted F antenna of the present invention is used, the antenna unit can be unitized and can be easily attached / detached from / to the metal case, and the antenna unit can be installed at the factory. It is possible to eliminate troublesome work such as soldering a certain ground conductor plate to a metal housing, and easily connect the plate-shaped inverted F antenna section to the metal housing with a removable metal material such as a metal screw. , Can be removed. Further, even when the plate-shaped inverted F antenna portion is broken, only the antenna portion can be replaced.

Further, if the plate-shaped inverted F antenna units are connected in advance using the same metal casing and the impedance matching is adjusted, the assembly process of the antenna part is performed by the metal connector connected to one side of the power supply line. Can be connected to the antenna connector of the wireless device, and the ground conductor plate, which is the ground plate, can be connected to the metal housing with metal screws, which is a simple operation.

Further, by connecting the outer conductor of the feeding coaxial line to the ground conductor plate, the radiation conductor plate can be grounded to the metal casing when the ground conductor plate is connected to the metal casing with metal screws or the like. As a result, it is possible to adopt a configuration in which the outer conductor of the coaxial line is not soldered to a metal housing that is difficult to solder.

Further, by providing a matching circuit section for impedance matching on the radiation conductor plate and arranging a capacitor in the matching circuit section and feeding power through the capacitor, a high impedance is obtained even at a relatively low frequency such as 400 MHz band. Impedance matching can be performed on the plate-shaped inverted F antenna, and a 400 MHz band plate-shaped inverted F antenna unit can be configured. Further, by using a variable capacitor in the matching circuit section, it is possible to adjust the deviation of impedance matching.

[Brief description of drawings]

FIG. 1 is a perspective configuration diagram of a plate-shaped inverted F antenna according to an embodiment of the present invention.

FIG. 2 is a side sectional view when the antenna is connected to a metal housing.

FIG. 3 is a plan view showing a radiation conductor plate of the antenna.

FIG. 4 is a perspective configuration diagram of a conventional plate-shaped inverted antenna for a mobile radio device.

[Explanation of symbols]

 1 Radiation Conductor Plate 2 Ground Conductor Plate 3 Metal Material 4 Matching Circuit Section 5 Coaxial Line 6 Capacitance 7 Metal Screw 8 Coaxial Wire Central Conductor 9 Coaxial Wire Outer Conductor 10 Metal Connector 11 Metal Case 12 Cutout 13 Metal Material Connection part 14 Coaxial wire center conductor connection part 15 Through hole 16 Dielectric

Claims (7)

[Claims] 1. A radiation conductor plate, a ground conductor plate arranged in parallel with the radiation conductor plate, a first metal material connecting the radiation conductor plate and the ground conductor plate, and the ground conductor plate. A metal housing having parallel surfaces; and a second metal material electrically connecting the ground conductor plate and the metal housing, and between the radiation conductor plate and the ground conductor plate. Plate-shaped reverse F that supplies power
antenna. 2. The plate-shaped inverted F antenna according to claim 1, wherein the second metal material is a metal screw. 3. The plate-shaped inverted F antenna according to claim 1, wherein the outer conductor of the coaxial line for feeding power is connected to the ground conductor plate. 4. The plate-shaped inverted F antenna according to claim 1, 2 or 3, wherein the radiation conductor plate and the ground conductor plate are printed circuit boards. 5. The plate-shaped inverted F antenna according to claim 1, wherein a matching circuit portion is provided on a part of the radiation conductor plate. 6. A plate-shaped inverted F antenna as set forth in claim 5, wherein a capacitor is arranged in the matching circuit section and the power is fed through the capacitor. 7. The plate-shaped inverted F antenna according to claim 6, wherein the capacitance is variable.