JP2003101333A - Micro-strip antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a further miniaturized, low-cost micro-strip antenna while maintaining antenna properties of the same level with the conventional art. SOLUTION: In the micro-strip antenna in which a radiating conductor 4 and a grounding one 7 are arranged to face each other via at least three dielectric layers, the radiating conductor 4 is provided on the top surface of a first dielectric layer 1, a conductor pattern 5 for a high-frequency circuit is formed, and a part 6 for the high-frequency circuit is arranged on the bottom surface of the first dielectric layer 1. The antenna is formed in multiple layers by stacking a second dielectric layer 2 having a hole 2a larger than the space occupied by the part 6 for the high-frequency circuit and a third dielectric layer 3 having the grounding conductor 7 on the bottom surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microstrip antenna used for mobile communication such as Global Positioning System (GPS), and more particularly to a circuit-embedded microstrip antenna having a high frequency circuit function. It is about.

[0002]

2. Description of the Related Art In a conventional microstrip antenna provided with an RF circuit, for example, Japanese Patent Application No. 2000-175.
As shown in FIG. 3 of the specification of Japanese Patent Publication No. 985, the antenna section has a radiation conductor disposed on the upper side and a ground conductor disposed on the lower side through one dielectric layer, and the RF circuit section uses a dielectric substrate different from the antenna section. A grounding conductor is disposed on the upper part of the interposing structure, a filter or a high-frequency circuit component including the filter is disposed on the lower part, and the lower part of the antenna part and the upper part of the RF circuit part are bonded with, for example, double-sided tape or the like.

[0003]

In recent years, with the development of mobile communication, miniaturization and cost reduction of parts including an antenna are desired. In the conventional example, a circuit board on which a filter or a high-frequency circuit component including the filter is mounted is prepared separately from the antenna board, and the respective ground conductor sides are stacked.

In order to achieve further miniaturization in such a structure, (1) the thickness of the microstrip antenna is reduced, (2) the thickness of the circuit board and the thickness of the high frequency circuit component including the filter or the filter. There is a method to reduce the size. However, (1) leads to deterioration of antenna characteristics, and (2) leads to deterioration of characteristics, reliability, etc. In any case, there is a limit to miniaturization. Further, since a high frequency substrate is required in addition to the microstrip antenna substrate, there is a problem that the cost becomes high.

An object of the present invention is to solve the above drawbacks of the prior art and to provide a microstrip antenna which is further miniaturized and reduced in price while maintaining the antenna characteristics at the same level as the conventional one. It is in.

[0006]

In order to achieve the above object, a first means is a microstrip antenna in which a radiation conductor and a ground conductor are arranged to face each other via at least three dielectric layers, A radiation conductor is provided on the upper surface of the first dielectric layer, a conductor pattern for a high-frequency circuit is formed on the lower surface of the first dielectric layer, and a high-frequency circuit component is arranged, which is larger than the space occupied by the high-frequency circuit component. It is characterized in that a second dielectric layer having a hole portion and a third dielectric layer having a ground conductor on the lower surface are stacked to form a multilayer structure.

The second means is the same as the first means,
A conductor pattern for a surface acoustic wave chip (hereinafter referred to as a SAW chip) is provided as a conductor pattern, and a SAW chip is provided as a high frequency circuit component.

According to the present invention, the high-frequency circuit component is built in the dielectric layer forming the antenna as described above, so that the size in the height direction can be reduced. Further, since it is not necessary to separately prepare the antenna and the circuit board, it is possible to reduce the manufacturing process and the cost.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 is a perspective view of a microstrip antenna according to the first embodiment, FIG. 2 is an exploded perspective view of the microstrip antenna, and FIG. 3 is a configuration diagram of a first dielectric layer of the microstrip antenna.
(A) is a top view, (b) is a side view, (c) is a bottom view.

The circuit built-in type micro slit top antenna shown in these figures is used for mobile communication such as GPS. In these drawings, a microstrip antenna with a built-in circuit is a substantially square-shaped microstrip antenna made of a resin-based dielectric material such as a glass-based fluororesin (relative permittivity: 10). It is composed of one dielectric layer 1, a second dielectric layer 2 and a third dielectric layer 3.

On the upper surface of the first dielectric layer 1, a radiation conductor 4 made of, for example, copper having a substantially square shape is formed, and on the lower surface of the first dielectric layer 1, a high frequency wave made of, for example, copper. A conductor pattern 5 for a circuit is formed, and a high frequency circuit component 6 is mounted on the conductor pattern 5.

If the area occupied by the conductor pattern 5 for the high frequency circuit is large, the gain characteristic and the directivity characteristic of the antenna are adversely affected. Therefore, for example, a semiconductor chip is used as the high frequency circuit component 6, and wire bonding or bumping is used. The area occupied by the conductor pattern 5 is made as small as possible by connecting with the conductor pattern 5 for the high frequency circuit,
It is set to 1/5 or less of the area of the conductor pattern 5.

The vertical and horizontal dimensions of the second dielectric layer 2 are
Although it is exactly the same as the first dielectric layer 1, as shown in FIG. 2, the square hole 2a larger than the area where the high frequency circuit component 6 is arranged has the high frequency circuit component 6 arranged therein. It is opened at the same place where it is. Further, the thickness of the second dielectric layer 2 is equal to the high frequency circuit component 6
Since it needs to be thicker than this, it is set to about 1 mm.

On the lower surface of the third dielectric layer 3, a ground conductor 7 made of, for example, copper is formed. This third
The vertical and horizontal dimensions of the dielectric layer 3 are the same as those of the first dielectric layer 1
The thickness is about 0.5 mm. In FIG. 3, reference numeral 8 is a feeding point, 9 is a through hole, 10 is an output line, and 11 is an output terminal. Further, in FIG. 2, reference numeral 12 indicates a cut.

Next, the operation of the circuit-embedded microstrip antenna when receiving a GPS signal will be described.
The signal transmitted from the GPS satellite is received by the radiation conductor 4 formed on the upper surface of the first dielectric layer 1 of the microstrip antenna with a built-in circuit, and the signal is fed to the feeding point 8
Through the through-hole 9 connecting the radiation conductor 4 and the conductor pattern 5 for the high-frequency circuit, the unnecessary interference signal is removed and the desired signal is amplified by the high-frequency circuit component 6, and the output terminal is passed through the output line 10. 11 is output. here,
A notch 12 is provided in the second dielectric layer 2 to facilitate soldering to the output terminal 11.

4A and 4B are configuration diagrams of the first dielectric layer used in the microstrip antenna according to the second embodiment. FIG. 4A is a top view, FIG. 4B is a side view, and FIG. 4C is a bottom view. Is.

In this embodiment, only the SAW chip is mounted as the high frequency circuit component 6. In the figure, those having the same functions as those in FIGS. 1 to 3 are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 1C, the conductor pattern 5 for the high frequency circuit is formed on the lower surface of the first dielectric layer 1.
The SAW chip 21 is mounted on the SAW chip conductor pattern 20 formed with a smaller pattern area.

Generally, the SAW chip 21 uses aluminum for the electrodes, and since it easily causes migration, it is used after being filled with an inert gas and sealed with a cap or the like. In the present embodiment, the SA
The W chip 21 can be sealed by pressure-bonding the second dielectric layer 2 and the third dielectric layer 3 in an inert gas injection state.

According to the present embodiment, by incorporating the high frequency circuit component 6 inside at least three dielectric layers 1, 2 and 3 forming the antenna, it is possible to realize miniaturization particularly in the thickness direction. You can In the past, separate boards on which the antenna board and the high-frequency circuit component 6 were mounted were manufactured in separate steps, but since they can be manufactured in a single step, cost reduction can be realized. it can.

[0021]

As described above, according to the present invention, in the microstrip antenna in which the radiation conductor and the ground conductor are arranged to face each other through at least three dielectric layers, the upper surface of the first dielectric layer is provided. A radiation conductor is provided, a conductor pattern for a high-frequency circuit is formed on the lower surface of the first dielectric layer, a high-frequency circuit component is arranged, and a hole larger than the space occupied by the high-frequency circuit component is provided. The second dielectric layer and the third dielectric layer having a ground conductor on the lower surface are stacked to form a multilayer structure.

Therefore, the high frequency circuit component is built in the three dielectric layers, and as a result, it is possible to reduce the thickness. Further, since the antenna part and the high frequency circuit part can be manufactured in one step, the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view of a microstrip antenna according to a first embodiment.

FIG. 2 is an exploded perspective view of the microstrip antenna.

3A and 3B are configuration diagrams of a first dielectric layer of the microstrip antenna, FIG. 3A is a top view, FIG. 3B is a side view, and FIG. 3C is a bottom view.

4A and 4B are configuration diagrams of a first dielectric layer used in the microstrip antenna according to the second embodiment, FIG. 4A is a top view, FIG. 4B is a side view, and FIG. 4C is a bottom view. .

[Explanation of symbols]

1 First dielectric layer 2 Second dielectric layer 2a hole 3 Third dielectric layer 4 Radiation conductor 5 conductor pattern 6 High frequency circuit parts 7 Ground conductor 8 feeding points 9 Through holes 10 output lines 11 output terminals 12 notches 20 SAW chip conductor pattern 21 SAW chip

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5J021 AA01 AB06 CA06 FA17 FA26                       GA08 HA05 HA07 HA10 JA08                 5J045 AA05 AB05 DA10 EA07 HA06                       NA01                 5J046 AA04 AA07 AB13 PA07                 5J047 AA04 AA07 AB13 FD01

Claims (2)

[Claims] 1. A microstrip antenna in which a radiation conductor and a ground conductor are arranged to face each other via at least three dielectric layers, and the radiation conductor is provided on the upper surface of the first dielectric layer, and the first dielectric layer is provided. A conductor pattern for a high-frequency circuit is formed on the lower surface of the body layer to dispose a high-frequency circuit component, and a second dielectric layer having a hole larger than the space occupied by the high-frequency circuit component and a ground conductor on the lower surface. Having a third
A microstrip antenna characterized in that the dielectric layers of are laminated to form a multilayer. 2. The microstrip antenna according to claim 1, wherein a surface acoustic wave chip conductor pattern is provided as the conductor pattern, and a surface acoustic wave chip is provided as the high frequency circuit component. .