JP2000114843A - Surface mount antenna, antenna device using it and communication equipment using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it immune to adverse effects such as deterioration in S/N ratio of a received signal by providing a connecting electrode for connecting the other end of a radiation electrode and a first ground electrode on one end face of a substrate, a power feeding electrode formed by arranging its one end closely to one end of the radiation electrode, and a noise reducing means installed on the substrate. SOLUTION: Concerning a surface mount antenna 20, a second ground electrode 21 is formed on nearly the whole surface of an end face 2d, which is opposed to an end face 2c forming the connecting electrode 5 of the substrate 2, being connected to a first ground electrode 3 and being insulated from the power feeding electrode 6. This ground electrode 21 functions as the noise reducing means. Consequently, the antenna 20 hardly picks up noises coming from the end face 2d forming the second electrode 21 of the substrate 2, thereby it becomes immune to adverse effects such as S/N deterioration of the received signal. In addition, by providing a second ground electrode 21 on the end face 2d of the substrate, the directivity of radio waves in the direction of the end face 2c of the substrate 2 is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface-mounted antenna, an antenna device using the same, and a communication device using the same, particularly a surface-mounted antenna used for a PMC card for PCMCIA and an antenna device using the same. And a communication device using the same.

[0002]

2. Description of the Related Art With the recent development of mobile computing, data communication between computers using a mobile communication system has been prosperous. The demand for the card type communication device is increasing. Therefore, miniaturization and high performance of the antenna mounted thereon are required.

FIG. 5 is a perspective view of a conventional surface mount antenna. The basic configuration of the surface mount antenna 1 shown in FIG. 5 is shown in Japanese Patent Application Laid-Open No. 9-98015. In FIG. 5, the surface mount antenna 1 is configured by forming several electrodes on the surface of a rectangular parallelepiped base 2 made of a dielectric such as ceramics or resin, which is one of the insulators. First, a ground electrode 3 is formed on almost the entire one main surface 2a of the base 2. A radiation electrode 4 is formed on the other main surface 2 b of the base 2, one end 4 a of the radiation electrode 4 forms an open end, and the other end 4 b is a connection electrode formed on one end surface 2 c of the base 2. 5 is connected to the ground electrode 3. A power supply electrode 6 is formed on another end face 2d of the base 2 opposite to the end face 2c on which the connection electrode 5 is formed. Here, one end of the feed electrode 6 goes around the other main surface 2b of the base 2 and approaches one end 4a of the radiation electrode 4,
The other end extends around one main surface 2 a of the base 2 and is provided insulated from the first ground electrode 3. In an actual surface mount antenna, in addition to the above-described electrodes, a fixing electrode may be provided on one end surface of the base 2 by soldering or the like, but this is not a main part of the present invention. Is omitted here.

FIG. 6 is a perspective view of a conventional antenna device using the surface mount antenna 1 shown in FIG.
In FIG. 6, the antenna device 10 includes a surface-mount type antenna 1 and a mounting board 11. Here, the mounting substrate 11 has a substrate ground electrode 13, a power supply line 14, and a signal processing circuit mounting portion 15 formed on one main surface 12a of an insulating substrate 12, and the signal processing circuit mounting portion 15 has a signal processing circuit ( (Not shown). The surface-mounted antenna 1 is configured such that one main surface 2 a of the base 2 faces the one main surface 12 a of the substrate 12, the end surface of the base 2 on which the connection electrode 5 is formed faces the end of the substrate 12, and further grounding. The electrode 3 is mounted on the substrate ground electrode 13 and the power supply electrode 6 is connected to the power supply line 14, respectively.

[0005]

In the antenna device 10 configured as shown in FIG. 6, the signal processing circuit mounting portion 15
Is provided with a signal processing circuit such as an analog circuit such as an amplifier and a mixer, a digital circuit, and a power supply circuit. Many noises 16 are generated from the signal processing circuit. However, in the antenna device 10, the noise 16 generated from the signal processing circuit is picked up by the surface-mounted antenna 1, and the S / S of the signal received by the surface-mounted antenna 1 is reduced. There is a problem that the N ratio is adversely affected, such as deterioration.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a surface mount antenna which is hardly affected by noise from a signal processing circuit, an antenna device using the same, and a communication device using the same.

[0007]

In order to solve the above problems, a surface mount antenna according to the present invention comprises a base made of an insulator having one main surface, another main surface, and a plurality of end surfaces; A first ground electrode mainly formed on one main surface;
A radiation electrode formed with one end open on the other principal surface of the base, a connection electrode for connecting the other end of the radiation electrode and the first ground electrode on one end surface of the base, It is characterized by comprising a feed electrode formed near one end of the radiation electrode and a noise reduction means provided on one end face of the base.

Further, in the surface mount antenna according to the present invention, the noise reduction means insulates the first surface of the base from the power supply electrode over substantially the entire other end surface of the base opposite to the end surface on which the connection electrode is formed. It is characterized by comprising a second ground electrode formed to be connected to the ground electrode.

Further, in the surface mount antenna according to the present invention, the second ground electrode is formed so as to extend from one end face of the base to the other main face.

Further, an antenna device according to the present invention comprises the above-mentioned surface-mounted antenna, and a mounting substrate on which the surface-mounted antenna is mounted, wherein the mounting substrate comprises an insulating substrate;
A signal processing circuit formed on at least one main surface of the substrate, wherein the surface-mount antenna has the noise reduction means of the substrate with one main surface of the substrate facing one main surface of the substrate. The end face is mounted so as to face the signal processing circuit formed on the mounting substrate.

[0011] A communication device according to the present invention is characterized by using the above antenna device.

With this configuration, the surface-mounted antenna of the present invention and the antenna device using the same can be made less susceptible to noise from the signal processing circuit.

Further, in the communication device of the present invention, the communication quality can be improved.

[0014]

FIG. 1 is a perspective view showing an embodiment of a surface mount antenna according to the present invention. 1, the same or equivalent parts as those in FIG. 5 are denoted by the same reference numerals, and description thereof will be omitted. However, the ground electrode 3 in FIG. 5 is the first ground electrode 3 for distinction from other parts in FIG.
Read as In FIG. 1, a surface mount antenna 20 is shown.
Is connected to the first ground electrode 3 and is insulated from the power supply electrode 6 to form a second ground electrode 21 on substantially the entire end surface 2d of the base 2 opposite to the end surface 2c on which the connection electrode 5 is formed. I have. Here, the second ground electrode 21 functions as a noise reduction unit.

With this configuration, in the surface mount antenna 20, almost no noise comes from the end face 2d of the base 2 on which the second ground electrode 21 is formed, and the S / N ratio of the received signal is reduced. Can be made less susceptible to adverse effects such as deterioration.

Further, since the second ground electrode 21 is provided on the end face 2d of the base 2, the position of the ground electrode with respect to the radiation electrode 4 is changed to the end face on which the second ground electrode 21 is formed from one main surface side of the base 2. Substantially tilt toward 2d. As a result, the direction of the radio wave radiated from the surface mount antenna 20 is inclined from the direction perpendicular to the other main surface 2b of the base 2 to the direction of the end surface 2c. Thereby, the directivity of the radio wave in the direction of the end face 2c of the base 2 can be enhanced.

Next, FIG. 2 shows a perspective view of an embodiment of the antenna device of the present invention using the surface mount antenna 20. As shown in FIG. 2, the same or equivalent parts as those in FIG. 6 are denoted by the same reference numerals, and the description thereof will be omitted. In the antenna device 25 shown in FIG.
With one main surface 2a of the base 2 facing the one main surface 12a of the substrate 12, the end surface 2c of the base 2 on which the connection electrode 5 is formed is connected to the substrate 1
2 and the second ground electrode 2 of the base 2
The end face 2 d on which the substrate 1 is formed is mounted facing a signal processing circuit (not shown) provided in the signal processing circuit mounting section 15 of the mounting board 11.

In the antenna device 25 configured as described above, most of the noise generated in the signal processing circuit is shielded and reflected by the second ground electrode 21 of the surface-mounted antenna 20, so that the surface-mounted antenna Numeral 20 hardly picks up noise 16 generated in the signal processing circuit. Therefore, the S / N ratio of the signal received by the surface mount antenna 20 hardly deteriorates.

According to an experiment performed by the inventor of the present invention, the antenna device 25 of the present invention shown in FIG. 2 has a higher S signal than that of the conventional antenna device 10 shown in FIG. It was confirmed that the / N ratio was improved by OO dB (under confirmation to the inventor).

When the antenna device 25 is used for a PCMCIA card, the surface mount antenna 20
The direction perpendicular to the end face of the base 2 is the direction horizontal to the ground, that is, the direction of the base station. Therefore, by increasing the directivity of the radio wave in the direction of the end surface 2c of the surface mount antenna 20, the radio wave can be easily transmitted and received, and the communication quality can be improved.

FIG. 3 is a perspective view showing another embodiment of the surface mount antenna of the present invention. 3, the same or equivalent parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 3, the surface mount antenna 30 is
A second ground electrode 31 connected to the first ground electrode 3 and insulated from the power supply electrode 6 is formed on almost the entire end face 2d of the base 2 opposite to the end face 2c on which the connection electrode 5 is formed.
The second ground electrode 31 is formed so as to partially extend to the other main surface 2 b of the base 2.

With this configuration, in the surface-mounted antenna 30, noise coming from the end face 2d of the base 2 on which the second ground electrode 31 is formed is no longer picked up, and the S / N ratio of the received signal is reduced. Can be further less susceptible to adverse effects such as deterioration. Further, in the antenna device using the surface mount antenna 30, deterioration of the S / N ratio caused by picking up noise generated in the signal processing circuit is further reduced. In addition, the directivity of radio waves in a direction perpendicular to the end surface of the base 2 of the surface mount antenna 30 can be further enhanced.

In each of the above embodiments, the shape of the radiating electrode and the connecting electrode of the surface-mount antenna is formed substantially linearly. The shape may be any. Further, although the power supply electrode 6 is formed so as to extend to the other main surface 2b of the base 2, it may be formed so as not to extend to the other main surface 2b. Further, the first ground electrode 3 and the second ground electrode 21 are completely connected at the boundary between the one main surface 2a and the end surface 2d of the base 2, but the first ground electrode 3 and the second ground electrode 21 are connected to each other. The ground electrodes 21 may be partially connected to the extent that no large inductance is generated, and may be used as a mark for fixing by soldering.
In addition, although a case has been described in which the substrate of the surface mount antenna uses a dielectric such as ceramics or resin, a magnetic body may be used.

FIG. 4 shows an embodiment of a communication device using the antenna device of the present invention. In FIG. 4, the communication device 40
It is a card type PHS terminal for CMCIA. Communication device 40
Is configured such that the antenna device 25 shown in FIG. The antenna device 25 includes the surface-mounted antenna 20 and the mounting substrate 11. A switching circuit 42, a transmission circuit 43, and a reception circuit 44, which are signal processing circuits, are provided on the mounting substrate 11,
The surface mount antenna 20 is connected to a transmission circuit 43 and a reception circuit 44 via a switching circuit 42. Although not particularly shown, a power supply circuit is also provided on the mounting board 11.

As described above, by using the antenna device 25 of the present invention, in the communication device 40, the surface-mounted antenna 20 is hardly affected by noise from the signal processing circuit, and the S / S of the received signal is thereby reduced. The deterioration of the N ratio can be reduced, and the communication quality can be improved.

[0026]

According to the surface mount antenna of the present invention,
A base made of an insulator having one main surface, another main surface, and a plurality of end surfaces; a first ground electrode formed mainly on the one main surface of the base; and an open end formed on the other main surface of the base mainly at one end. A connecting electrode for connecting the other end of the radiating electrode to the first ground electrode on one end surface of the base, a feed electrode having one end formed near one end of the radiating electrode, With the configuration including the noise reduction means provided on the two end faces, the noise coming from the end face on which the second ground electrode of the base is formed is hardly picked up,
It is possible to reduce the adverse effect such as deterioration of the S / N ratio of the received signal.

The noise reduction means is provided on a second ground electrode formed insulated from the power supply electrode and connected to the first ground electrode over substantially the entire other end face of the base opposite to the end face on which the connection electrode is formed. The directivity of the radio wave in the direction of the end face of the base on which the connection electrode is formed can be enhanced.

Further, by forming the second ground electrode from one end face of the base to the other main face, it becomes more resistant to noise coming from the end face where the second ground electrode is formed. Further, the directivity of the radio wave in the direction of the end face of the base on which the connection electrode is formed can be further enhanced.

In the antenna device of the present invention,
By mounting the end surface of the base of the above surface mount antenna on which the second ground electrode is formed toward the signal processing circuit on a mounting substrate, noise generated in the signal processing circuit can be picked up. S of the signal received by the mounted antenna
There is almost no adverse effect such as deterioration of the / N ratio.

In the communication device according to the present invention, by using the above antenna device, the surface mount antenna mounted on the antenna device is hardly affected by noise from the signal processing circuit inside the communication device. Therefore, deterioration of the S / N ratio of the received signal can be reduced, and communication quality can be improved.

[Brief description of the drawings]

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

FIG. 2 is a perspective view showing an embodiment of the antenna device of the present invention.

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

FIG. 4 is a perspective view showing one embodiment of the communication device of the present invention.

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

FIG. 6 is a perspective view showing a conventional antenna device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 2 ... Base 2a ... One main surface 2b ... The other main surface 3 ... First ground electrode 4 ... Radiation electrode 4a ... One end 4b ... Other end 5 ... Connection electrode 6 ... Feeding terminal 11 ... Mounting substrate 12 ... Substrate 13 ... Substrate grounding Electrode 14: Feeding line 15: Signal processing circuit mounting section 16: Noise 20, 30: Surface-mounted antenna 21, 31, Second ground electrode (noise reducing means) 25: Antenna device 40: Communication device 41: Housing 42 ... Switching circuit 43 ... Transmission circuit 44 ... Reception circuit

Claims (5)

[Claims] 1. A base made of an insulator having one main surface, another main surface, and a plurality of end surfaces, a first ground electrode formed mainly on one main surface of the base, and a main other main surface of the base. A radiation electrode formed with one end as an open end, a connection electrode for connecting the other end of the radiation electrode and the first ground electrode on one end surface of the base, and one end close to one end of the radiation electrode. And a noise reduction means provided on one end face of the base. 2. The noise reduction means is formed on substantially the entire other end face of the base opposite to the end face on which the connection electrode is formed, insulated from the power supply electrode and connected to the first ground electrode. A second ground electrode,
A surface-mounted antenna according to claim 1. 3. The surface-mounted antenna according to claim 2, wherein the second ground electrode is formed so as to extend from one end surface of the base to the other main surface. 4. An antenna device comprising the surface-mounted antenna according to claim 1 and a mounting board on which the surface-mounted antenna is mounted, wherein the mounting board is an insulating substrate. A signal processing circuit formed on at least one main surface of the substrate, wherein the surface-mounting antenna has the noise reduction unit of the base, with one main surface of the base facing one main surface of the substrate. An antenna device wherein the provided end face is mounted to face the signal processing circuit formed on the mounting substrate. 5. A communication device using the antenna device according to claim 4.