JPH11355033A - Antenna device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of components and to improve assemblabity in a antenna device provided with a plurality of antennas tuned to respective frequencies. SOLUTION: A plurality of antenna elements A1-A4 are formed on the same printed board P and a ground board Q is installed to be away from the printed board P by using spacers S1-S4, for example. Two through holes T1-T8 are provided in the antenna elements A1-A4. The antenna elements A1-A4 are connected to the ground plate Q by a ground conductor and the antenna elements A1-A4 are connected to a feeder conductor. A matching circuit can be connected to the antenna elements A1-A4. In such a case, by the matching circuit, respective antennas are tuned to respective frequencies. When a metallic screw is used as the ground conductor, the printed board P is fitted to the ground plate Q by the screw by leaving a space.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device having a plurality of antennas tuned to individual frequencies, and more particularly to an antenna device formed by forming a plurality of antenna elements on the same printed circuit board. The present invention relates to a technique for improving the assemblability of a device.

[0002]

2. Description of the Related Art For example, in communication equipment such as a small base station of a cellular phone system and a relay amplifier (booster),
Communication is performed using wireless signals in a plurality of different frequency bands. In such a case, such a communication device includes a plurality of antennas tuned to individual frequencies. As such an antenna, for example, a plate-shaped inverted-F antenna is often used in order to realize a reduction in size and posture.

FIG. 6 shows the configuration of a plate-shaped inverted-F antenna. This plate-shaped inverted-F antenna has, for example, a conductive plate (conductor plate) V and a ground plate W1 formed of four spacers S11.
It is configured to be fixed at a constant interval through S14. Further, for example, one end of each of two conductor bars (wires) D21 and D22 is connected to the conductor plate V, which is a plate portion, and the other end of one conductor bar D21 is connected to the ground plate W1. On the other hand, the other end of the other conductor bar D22 is connected to an external power supply circuit or the like via a connector C2 provided on the ground plate W1. In this configuration, power is supplied between the other end of the other conductor bar D22 and the ground plate W1.

FIG. 7 shows a configuration of an antenna device provided with four plate-shaped inverted-F antennas tuned to individual frequencies, respectively.
The four inverted flat-F antennas shown in (1) and (2) share the same ground plate W2. That is, four antenna elements A1 each composed of separate conductor plates
An antenna device including four plate-shaped inverted-F antennas is formed by sharing the same ground plate W2 with 1 to A14.

[0005]

However, in the above-described antenna device, when a plurality of antennas are provided, for example, the ground plate can be shared by the plurality of antennas, but each antenna can be shared. Since the antenna elements such as the conductor plate constituting the antenna must be provided separately for each antenna, there is a problem that such antenna elements must be manufactured separately for each antenna. For this reason, for example, there is a problem that the number of components increases according to the number of antennas provided in the antenna device, and a problem that the man-hour required for manufacturing the antenna device increases, resulting in poor assemblability of the antenna device. However, there is a problem that the cost of the antenna device is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem. In an antenna device having a plurality of antennas as described above, for example, the number of parts of the device is reduced to reduce assembly. An object of the present invention is to provide an antenna device having excellent performance.

[0007]

In order to achieve the above object, an antenna device according to the present invention includes a plurality of antennas tuned to individual frequencies as follows. That is, a plurality of antenna elements are formed on the same printed circuit board, a ground plate is provided separately from the printed circuit board, and each of the antenna elements is connected to the ground plate by a plurality of ground conductors. In addition, a feeding conductor was connected to each of the antenna elements. Therefore, for example, even when the number of antennas provided in the antenna device is large, the plurality of antennas are formed by sharing the same printed circuit board. Sex can be improved.

Further, in the antenna device according to the present invention, in the above configuration, a matching circuit is further connected to the antenna element, and each antenna is tuned to an individual frequency by the matching circuit. Therefore, for example, even when the antenna element itself is not tuned to the required frequency, by connecting a matching circuit to the antenna element, the antenna constituted by the antenna element can be set to the required frequency. Can be tuned. Therefore, for example, even when a plurality of antenna elements are formed in the same configuration on the same printed circuit board, each antenna can be tuned to an individual frequency using a matching circuit,
For this reason, for example, if all the antenna elements are formed in the same configuration on the same printed circuit board, the processing for forming such antenna elements can be easily performed, and the assemblability of the device can be improved. it can.

Further, in the antenna device according to the present invention, in the above configuration, the two are attached with a gap by a metal screw penetrating the printed board and the ground plate, and the screw is used as a ground conductor. The antenna element and the ground plate were connected. In such a configuration, the screw serves as a grounding conductor and also serves to maintain the distance between the printed board and the grounding plate, for example, within a certain interval. The number of points can be reduced and the assemblability of the device can be improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment according to the present invention will be described with reference to the drawings. FIG. 1 shows an example of an antenna device according to the present invention. The antenna device includes a printed circuit board P, a plurality of antenna elements A1 to A4 formed on the printed circuit board P, and 0 V, for example. A ground plate Q connected to a reference voltage, and spacers S1 to S4 for maintaining a distance between the printed circuit board P and the ground plate Q at a constant interval.
S4 and a ground conductor and a power supply conductor to be described later are provided. In FIG. 1, the ground conductor and the power supply conductor are not shown. In this example, an antenna device in which four antenna elements A1 to A4 are formed on the same printed circuit board P will be described, but the number of a plurality of antennas provided in the antenna device may be arbitrary.

The printed board P is made of, for example, an insulator, and a plurality of antenna elements A1 to A4 can be formed on the printed board P independently of each other.
In addition, the ground plate Q of the antenna is
Are provided separately from the printed circuit board P, for example, as described above.

Here, in order to hold the surface of the printed circuit board P and the surface of the ground plate Q at a constant interval, it is preferable that both P and Q are fixed at at least three points using, for example, a spacer. In this example, the printed circuit board P and the ground plate Q
By inserting four spacers S1 to S4 between them, the distance between both P and Q is maintained at a constant interval.
The number of spacers and the like inserted between the printed board P and the ground plate Q is not particularly limited. For example, as the number of inserted spacers increases, the strength of the device can be increased. In addition, it is possible to reduce a variation in a manufacturing error occurring in a distance between the printed board P and the ground plate Q.

Each of the antenna elements A1 to A4 is, for example, a conductor pattern formed by printing on the same printed circuit board P. To A4. The antenna provided in the antenna device of the present invention is not limited to the above-described plate-shaped inverted-F antenna, and various antennas may be used. May be formed. Further, for example, different types of antennas may be formed by the respective antenna elements A1 to A4.

In this embodiment, each of the antenna elements A1 to A
4, two through holes T1 to T8 are provided as short-circuit portions. As will be described later, each of the antenna elements A1 to A4 uses these through holes T1 to T8 to form a ground plate Q, a feed circuit, and the like. Connected. Further, in this example, the case where the antenna elements A1 to A4 are formed using only one surface of the printed circuit board P, that is, only the surface of the printed circuit board P that is not opposed to the ground plate Q is shown.
The other surface of the printed circuit board P has through holes T1 to
Although no conductor pattern other than the T8 portion is formed, for example, the antenna elements A1 to
A configuration in which A4 is formed may be used.

The plurality of antennas constituted by the antenna elements A1 to A4 formed as described above are formed by, for example, the size and shape of the antenna element itself, and by connecting a matching circuit to the antenna element, for example. , Each tuned to an individual frequency. Here, the matching circuit includes, for example, a coil and a capacitor, and has a function of tuning an antenna configured by an antenna element connected to the matching circuit to a specific frequency. When such a matching circuit is used, for example, the antenna elements A1 to A4 can be formed in the same configuration on the printed circuit board P, so that the processing for forming such antenna elements can be simplified.

Such a matching circuit may be provided, for example, for all antenna elements, or may be provided, for example, for only some of the antenna elements. Further, the matching circuit may be formed by using a substrate other than the above-described printed circuit board P. However, when the matching circuit is formed by using the above-described printed circuit board P, for example, the number of components is further reduced and the antenna The assemblability of the device can be improved.

Next, each of the above-described antenna elements A1 to A4
A configuration in which a ground conductor and a power supply conductor are connected to the ground plate Q and a power supply circuit using through holes T1 to T8 will be described. In this example, the configuration of such connection is the same for each of the antenna elements A1 to A4, and therefore, only the configuration of one antenna element A1 is illustrated and described. FIG. 2 is a cross-sectional view of the printed circuit board P, the ground plate Q, and the like shown in FIG. 1 taken along the line XX. FIG. 2 shows a cross section of one antenna element A1 as an example. In the figure, the illustration of the spacer S1 is omitted.

As shown in FIG. 1, an antenna element A1 formed on a printed circuit board P is provided with the above-described two through holes T1 and T2, and the antenna element A1 has one through hole T1. Of one end of a conductive pin (conductor bar) D1 which is a grounding conductor, and one end of a conductive pin (conductor bar) D2 which is a power supply conductor via the other through hole T2. One end and the solder H3 are joined. The other end of the ground conductor pin D1 is connected to the ground plate Q by solder H2, while the other end of the power conductor pin D2 is connected to a power supply circuit (not shown). Here, the power supply to the antenna element A1 is performed, for example, between the point M and the point N shown in FIG.
Is done between A more detailed configuration of the power supply conductor D2 will be described later.

Here, FIG. 2 shows a configuration in which the antenna element A1 and the ground plate Q are connected using conductive pins as ground conductors. However, for example, a metal screw may be used as the ground conductor. . FIG. 3 shows only a portion near the one through-hole T1 in the cross section taken along the line XX shown in FIG. 2 so that, for example, a screw B is used as a metal screw as described above. An example of a configuration in which the antenna element A1 and the ground plate Q are connected is shown.

In this configuration, the printed board P and the ground plate Q
Are mounted with a gap therebetween by screws B penetrating both P and Q. For example, on the printed circuit board P side, the head of the screw B is in contact with the antenna element A1, while on the ground plate Q side, The screw B is attached to the ground plate Q by attaching the screw B with the nut Z on the surface not facing the substrate P.
In the present embodiment, as a preferred embodiment, the printed circuit board P
Spacers S5 and S6 are inserted in the vicinity of the screw B provided to penetrate through the ground plate Q.

In the above configuration, the distance between the printed circuit board P and the ground plate Q is prevented from becoming too close, for example, by the spacers S5 and S6. , Q are prevented from being too far apart, so that both P,
The distance between Q is kept at a constant interval. As described above, when the metal screw is used as the ground conductor, the printed board P and the ground plate Q can be fixed by the screw, so that, for example, the number of components is reduced and the assemblability of the device is improved. can do.

The manner in which the printed circuit board P and the ground plate Q are attached using the metal screws is not necessarily limited to the one shown in this embodiment, but the point is that both P and Q can be fixed. With the antenna element A1 and the ground plate Q
If the configuration is such that the device can be connected, the assemblability of the device can be improved. As a specific example, for example, a configuration in which a spacer is provided at a position relatively distant from the screw without providing a spacer in the vicinity of the screw may be used. The distance between the printed board P and the ground plate Q can be fixed at a constant interval by a configuration in which the ground plate Q is sandwiched and fixed between the nuts connected to the screws while the pin is fixed.

FIG. 4 shows a more detailed configuration example on the side of the feeder conductor D2 by showing only the portion near the other through hole T2 in the cross section taken along the line XX shown in FIG. is there. As shown in FIG. 4, one end of a pin D2 serving as a feed conductor is connected to an antenna element A1 on a printed circuit board P.
The other end of the pin D2 is connected to a power supply circuit (not shown) via a connector C1 provided on the surface of the ground plate Q. Here, the connector C1 is
It serves to prevent the contact between the pin D2 serving as the power supply conductor and the ground plate Q.

Further, for example, a semi-rigid cable can be used as the power supply conductor. FIG.
Similarly to FIG. 2, only a portion near the other through-hole T2 in the cross section taken along the line XX shown in FIG. 2 is shown to show a configuration example in which a semi-rigid cable R is used as a power supply conductor. . Here, the semi-rigid cable R includes, for example, an inner conductor and an outer conductor that are not in contact with each other.

In the configuration shown in FIG. 5, for example, one end of the inner conductor D11 of the semi-rigid cable R is joined to the antenna element A1 on the printed circuit board P by solder H11, while one end of the outer conductor of the semi-rigid cable R is connected. Are brought into contact with the ground plate Q and fixed. For example, the one end of the outer conductor of the semi-rigid cable R and the ground plate Q may be soldered. Also, one end of the inner conductor of the semi-rigid cable R and the antenna element A
It is not necessary to use a configuration in which the first and the first are directly connected,
For example, a configuration in which one end of the inner conductor is connected to the antenna element A1 via a conductive pin or the like may be used. Further, in such a configuration, for example, power is supplied between the inner conductor and the outer conductor forming the semi-rigid cable R.

The ground conductor and the feed conductor provided for one antenna element A1 have been described above.
In this example, since four antenna elements A1 to A4 are provided on the same printed circuit board P, in the antenna device of this example, the same ground conductor and feeder conductor as described above are provided for each of the antenna elements A1 to A4. In other words, the antenna device is provided with a plurality of ground conductors and feed conductors.

A ground conductor for connecting each of the antenna elements A1 to A4 and the ground plate Q, and each of the antenna elements A1 to A4
It is not always necessary to use the pins and the like shown in the present example as the power supply conductor connected to the power supply conductor.In short, various types of conductive conductors may be used as the ground conductor and the power supply conductor. Good. In addition, soldering is not necessarily used as a connection between the antenna element and the conductor or a connection between the ground plate and the conductor. In other words, as long as the antenna element and the conductor can be electrically connected. , Any connection method may be used.

With the above-described configuration, in the antenna device of the present embodiment, a plurality of antennas tuned to individual frequencies are provided so as to share the same printed circuit board P. Further, the antenna device of the present example is provided in a communication device such as a small base station or a relay amplifier device of a mobile phone system, and each antenna provided in the antenna device of the present example is provided with the antenna device, for example. The communication device is tuned to each of a plurality of frequencies used in wireless communication. The field to which the antenna device of the present invention is applied is not necessarily limited to the field of a mobile phone system. For example, any communication device that performs wireless communication using a plurality of different frequency bands can be applied to various communication devices. The present invention can be applied.

As described above, in the antenna device of this embodiment,
For example, the device can be assembled only from one printed circuit board on which a plurality of antenna elements are formed, one ground plate, and pins and spacers provided between the two. Is excellent. That is, in the antenna device of this example, since a plurality of antenna elements are formed by sharing the same printed circuit board, for example, the number of parts of the device can be reduced, thereby reducing the number of manufacturing steps. As a result, the assemblability can be improved, and the cost of the apparatus can be reduced.

In the antenna device of the present embodiment, a plurality of antenna elements are formed using separate conductor plates as shown in FIG. 7 of the conventional example, for example, due to the influence of the dielectric constant of the printed circuit board. In some cases, it is necessary to reduce the size of the antenna element as compared with the case where the antenna is configured.However, in the antenna device of this example, since the printed board and the ground plate are separated from each other with a certain interval, for example, Influence of the dielectric constant of
For example, power loss at the antenna can be suppressed to a small level, so that there is no particular problem.

Therefore, in the antenna device of the present embodiment, a substrate made of an inexpensive material can be used as the printed circuit board, except for a case where the antenna is miniaturized by positively utilizing the dielectric constant of the printed circuit board, for example. Thus, the cost of the apparatus can be reduced. The distance between the printed circuit board and the ground plate may be arbitrarily set according to the use state of the apparatus, the state of assembly, and the like.

For example, in a conventional microstrip antenna in which an antenna element is formed on one surface of a printed circuit board and the other surface is used as a ground plate, the interaction between the antenna element and the ground plate surface, Although the influence of the dielectric constant of the substrate and the loss of power at the antenna become relatively large, the antenna device of the present example differs from such a microstrip antenna in the structure and electrical characteristics of the device, and as described above. In addition, it is possible to obtain an effect that the influence of the dielectric constant of the printed circuit board can be reduced.

It should be noted that the ground plate Q constituting the antenna device shown in FIG.
Is formed from a printed circuit board different from the printed circuit board P on which is formed, and one surface of the printed circuit board constituting the ground plate Q is used as a ground plate surface, and a power supply circuit or the like is formed on the other surface. May be used. In such a configuration, power can be supplied from the microstrip on the ground plate Q side.

[0034]

As described above, according to the antenna device of the present invention, a plurality of antennas tuned to individual frequencies are formed by sharing the same printed circuit board. By reducing the number of points, the assemblability of the device can be improved. Also, according to the antenna device of the present invention, since a matching circuit is connected to the antenna element and each antenna is tuned to an individual frequency by the matching circuit, for example, as described above, the antenna element is mounted on a printed circuit board. The forming process can be simplified, and the assemblability of the device can be improved.

According to the antenna device of the present invention, the antenna element and the ground plate are connected using the metal screw, and the printed circuit board and the ground plate are attached and fixed using the screw. Therefore, the assemblability of the device can be further improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of an antenna device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration example of an antenna device.

FIG. 3 is a diagram for explaining a configuration example when a screw is used as a ground conductor.

FIG. 4 is a diagram illustrating a configuration example of a power supply conductor.

FIG. 5 is a diagram for explaining another configuration example of the power supply conductor.

FIG. 6 is a diagram illustrating a configuration of a plate-shaped inverted-F antenna according to a conventional example.

FIG. 7 is a diagram showing a configuration of an antenna device according to a conventional example.

[Explanation of symbols]

P .. Printed circuit board, Q .. Ground plate, A1-A4.
-Antenna element, S1-S6-Spacer, T1-
T8 ・ ・ Through hole, H1-H3, H11 ・ ・ Solder,
D1 ... ground conductor, D2 ... power supply conductor, D11 ...
Inner conductor, B. screw, Z nut, C1 connector, R semirigid cable,

Claims (3)

[Claims] 1. An antenna device having a plurality of antennas tuned to individual frequencies, wherein the plurality of antenna elements are formed on the same printed circuit board and are separated from the printed circuit board. An antenna device, comprising: a ground plate; a plurality of ground conductors connecting the antenna elements to the ground plate; and a plurality of feed conductors connected to the antenna elements. 2. The antenna device according to claim 1, wherein the antenna element is connected to a matching circuit, and each antenna is tuned to an individual frequency by the matching circuit. 3. The antenna device according to claim 1, wherein the printed board and the ground plate are attached with a gap by a metal screw penetrating both, and the screw is used as a ground conductor. An antenna device, wherein an antenna element and the ground plate are connected.