JPH0998010A - Surface mount antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface mount antenna which radiates the ratio waves in the prescribed direction when mounted in a circuit board. SOLUTION: A through-hole 2 having the length of λ/4 or less is formed covering a face 1a through its counter face 1b of a dielectric or magnetic substrate 1 with offset secured toward one of both sides from the center of the substrate. Then a feeding electrode 2a is formed in the through-hole 2, and a feeding terminal 3 and the ground terminals 4a and 4b are formed on the face 1a. Furthermore, a radiation electrode 5 is formed on the face 1b. The terminal 3 is connected to the electrode 5 via the electrode 2a, and a face 1c which is adjacent to the face 1a is used as a mounting surface of an antenna.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount antenna used for mobile communication devices such as mobile phones, wireless LAN (Local Area Network) and the like.

[0002]

2. Description of the Related Art A conventional patch antenna is shown in FIG.
In this patch antenna, the radiation electrode 21 is provided on the front surface of the dielectric substrate 20, the ground electrode 22 is mainly provided on the back surface, and the feeding electrode 23 is provided on a part of the back surface so as to be insulated from the ground electrode 22. And the radiation electrode 21 on the surface are connected by a through hole 24.

A conventional surface mount antenna is shown in FIG. In this surface mount antenna, a through hole 33 is formed from one end surface 31 of the dielectric substrate 30 to the opposite end surface 32, and a radiation electrode 34 is formed in this through hole 33, and one end surface of the dielectric substrate 30 is formed. 31 is provided with a power supply terminal 35 and ground terminals 36a and 36b, and the end surface 3 facing each other.
2 is provided with a capacitance loading electrode 37, and both ends of the radiation electrode 34 provided on the inner surface of the through hole 33 are connected to the feeding terminal 35 and the capacitance loading electrode 3 respectively.
7 and 7, respectively. This surface-mounted antenna is mounted on the board 38 so that the feeding terminal 35 and the board 38
Power supply conductor 39, ground terminals 36a and 36b, and substrate 3
The eight ground conductors 40a and 40b are soldered to each other.

[0004]

However, in the conventional patch antenna shown in FIG. 4, the radiation direction of radio waves is perpendicular to the mounting substrate (radiation electrode) (Z direction of the additional coordinates).

Further, in the conventional surface mount antenna shown in FIG. 5, the peripheral direction of the through hole 33 (XZ plane direction of additional coordinates).
Radio waves will be strongly emitted to.

Therefore, each of the conventional antennas has a small radiation component of radio waves in the direction of the substrate (XY plane). For example, when mounted on a PC card, there are many radiation components of radio waves in an unnecessary direction, so that the effective direction The radiation component of the radio wave was small.

Therefore, according to the present invention, when mounted on a substrate,
An object of the present invention is to provide a surface mount antenna that radiates a radio wave in a predetermined mounting board direction.

[0008]

In order to achieve the above object, the present invention has a length of λ / 4 or less from one surface of a substrate made of at least one of a dielectric material and a magnetic material to the opposite surface. A through hole having is formed offset from the center of the base body to one side, a power supply electrode is formed on the inner surface of the through hole, and a power supply terminal and a ground terminal are formed on the one surface. A radiation electrode is formed on a surface facing one surface, the power supply terminal is connected to the radiation electrode through the power supply electrode of the through hole, and one surface adjacent to the one surface is a mounting surface. It is characterized by

According to the present invention, in the surface mount antenna according to claim 1, one end of the radiation electrode is connected to a ground electrode.

Further, according to the present invention, in the surface mount antenna according to claim 1, the surface on which the radiation electrode is formed is inclined with respect to the surface on which the feeding terminal and the ground terminal are formed. It is characterized by being

As described above, according to the present invention, since the through hole (feeding electrode) is formed to be shorter than λ / 4 and offset from the center of the base body to one side, the radio wave from the feeding electrode is There is no radiation, and a high-frequency current flows from one side of the radiation electrode to the other side, and radio waves are strongly radiated in a direction perpendicular to the radiation electrode and in a predetermined direction on the same surface as the mounting board. Therefore, the present invention is particularly effective in a communication device equipped with a PC card in which this mounting board is used horizontally.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the surface mount antenna of the present invention. A through hole 2 is formed from one surface 1a of a rectangular base 1 made of a dielectric material such as ceramics or a magnetic material such as ferrite to an opposing surface 1b, offset from the center of the base body 1 to one side. . A power supply electrode 2a is formed on the inner periphery of the through hole 2 and the through hole 2 (power supply electrode 2
a) has a length of λ / 4 or less of the used frequency and acts as a non-resonator. On one surface 1a of the base 1, a power supply terminal 3 and ground electrodes 4a and 4b are formed on both sides thereof. A radiation electrode 5 is formed on a surface 1b opposite to one surface 1a of the base body 1, and the radiation electrode 5 has λ open at both ends.
It constitutes a / 2 type radiator. The power supply terminal 3 is connected to the radiation electrode 5 via the power supply electrode 2 a of the through hole 2.

The surface mount antenna 10 according to this embodiment.
Is configured as described above, and is placed with one surface 1c adjacent to one surface 1a of the base 1 in contact with the mounting board 6 on which the power supply conductor 6a and the ground conductors 6b and 6c are formed, The power supply terminal 3 and the power supply conductor 6a, and the ground terminals 4a and 4b and the ground conductors 6b and 6c are connected by soldering, respectively.

In this embodiment, the through hole 2 (feeding electrode 2a) is provided offset from the center of the substrate 1 to one side (ground electrode 4b side), and is a non-resonant body having a working frequency of λ / 4 or less. Therefore, the high frequency signal applied from the power feeding conductor 6a is not radiated from the power feeding electrode 2a, but the whole is fed to the radiating electrode 5. Then, a high-frequency current flows through the radiation electrode 5 as indicated by arrow A, and radio waves are strongly radiated in a predetermined direction on the same plane as the surface of the substrate 6 in a direction perpendicular to the radiation electrode 5 as indicated by arrow B. Become. Therefore, in a communication device in which the substrate 6 is mounted horizontally, radio waves are radiated in a predetermined direction of the substrate 6, and if there is a receiver in the predetermined direction, the reception sensitivity of the device is improved.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. This embodiment is different from the first embodiment in that
The radiation electrode 5a formed on the surface 1b of the base 1 is
The difference is that it is connected to the ground electrode 4b through the short-circuit electrode 7 formed on the end face 1d of the above, and is a λ / 4 type surface-mounted antenna with one end open and the other end short-circuited. Others are the same as those in the first embodiment, and therefore, the same reference numerals as those in the first embodiment are attached and the description thereof is omitted. The same applies to the radio wave radiation direction.

Next, a third embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. This embodiment is different from the first embodiment in that
The surface 1e facing the one surface 1a of the base 1 is thickened on one end side,
The difference lies in that the radiation electrode 5b is formed on the inclined surface 1e with an inclination so as to be thin on the other end side. Others are the same as those in the first embodiment, and therefore, the same reference numerals as those in the first embodiment are attached and the description thereof is omitted. In this embodiment, since the radiation electrode 5b is inclined with respect to the one surface 1a on which the ground electrodes 4a and 4b are formed, the radiation direction of the radio wave is displaced as shown by the arrow C, and the radio wave becomes stronger. Since the direction can be changed, it can be incorporated in a communication device or the like to correct the emission direction of a radio wave due to the tilt of the communication device during use.

In this embodiment shown in FIG. 3, the radiating electrode 5b is thin on one end side and thick on the other end side, but the reverse is also possible, and in the figure, the upper side is inclined. You may have it.

[0018]

According to the present invention, since the through hole in which the power feeding electrode is formed is shorter than λ / 4 and is offset from the center of the base body to one side, the radio wave from the power feeding electrode is There is no radiation, and a high-frequency current flows from one side of the radiation electrode to the other side, and radio waves are strongly radiated in a direction perpendicular to the radiation electrode and in a predetermined direction on the same surface as the mounting board.

Further, in the case where the radiation electrode is inclined with respect to the ground electrode surface, the radiation direction of the radio wave can be displaced with respect to the mounting substrate.

[Brief description of drawings]

FIG. 1 is a perspective view of a first embodiment of a surface mount antenna according to the present invention.

FIG. 2 is a perspective view of a second embodiment of the surface mount antenna of the present invention.

FIG. 3 is a perspective view of a surface mount antenna according to a third embodiment of the present invention.

FIG. 4 is a perspective view of a conventional patch antenna.

FIG. 5 is a perspective view of a conventional surface mount antenna.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dielectric substrate 1a One surface 1b Opposing surface 1c One adjacent surface 1d End surface 1e Inclined surface 2 Through hole 2a Feeding electrode 3 Feeding terminal 4a, 4b Ground electrode 5, 5a, 5b Radiating electrode 6 Substrate 6a Feeding conductor 6b , 6c Ground conductor 7 Short-circuit electrode

Claims (3)

[Claims] 1. A through hole having a length of λ / 4 or less from one surface of a substrate made of at least one of a dielectric substance and a magnetic substance to an opposite face thereof is offset from the center of the substrate to one side. A power supply electrode is formed on an inner surface of the through hole, a power supply terminal and a ground terminal are formed on one surface of the base, and a radiation electrode is formed on a surface facing the one surface of the base. The surface mount antenna, wherein the power supply terminal is connected to the radiation electrode through a power supply electrode of the through hole, and one surface adjacent to the one surface is a mounting surface. 2. The surface mount antenna according to claim 1, wherein one end of the radiation electrode is connected to a ground electrode. 3. The surface mount antenna according to claim 1, wherein the surface on which the radiation electrode is formed is inclined with respect to the surface on which the power supply terminal and the ground terminal are formed. Surface mount antenna.