JPH09307340A - Antenna for portable radio equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna for a portable radio equipment consisting of a flat patch antenna which is easily manufactured and capable of tuning at a low cost. SOLUTION: The antenna 1 for a portable radio equipment consists of the flat patch antenna provided with a radiation board 3 consisting of a metallic panel, a metallic foil, an electrically conductive film, etc., a ground board 4 provided confronting this radiation board 3 in parallel and consisting of a metallic panel, a metallic foil, an electrically conductive film, etc., and a resin dielectric board 2 arranged between the radiation board 3 and the ground board 4. The dielectric board 2 is provided with a thinned and recessed part for tuning 8 the volume of which is not more than 50% of a volume obtained by multiplying the area of the radiation board 3 to the average thickness of the dielectric board 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna for a portable wireless device which is used by being built in a portable wireless device or the like.

[0002]

2. Description of the Related Art As an antenna for a portable wireless device, one side of a metal plate provided in parallel to face each other with a dielectric plate sandwiched therebetween is used as a radiating metal plate, and the opposite side is used as a ground metal plate to feed power to the radiating metal plate. Widely used are planar patch antennas that operate. An antenna for a portable wireless device including this planar patch antenna has a large change from the original characteristics when incorporated in a wireless device. In order to compensate for this characteristic change, tuning such as incorporating a compensation circuit or changing the shape of the metal plate is taken. However, there is a drawback that incorporating a compensation circuit leads to an increase in cost.

Further, when the shape of the metal plate is changed, no extra parts are required, but in order to change the shape of the metal plate, it is necessary to change the punching die, for example, and the equipment is changed. There is a drawback that the cost of will lead to a significant cost increase. As a means for solving the above-mentioned drawbacks, as disclosed in Japanese Utility Model Laid-Open No. 7-14714, a means for performing tuning by installing a slit for adjustment in advance on a metal plate and attaching a conductive tape to this Is proposed.

[0004]

[Problems to be Solved by the Invention]
The method of attaching a conductive tape to the slit disclosed in Japanese Patent Publication No. 7-14714 has a drawback that the long-term reliability of the conductive tape is poor. Further, since it is necessary to strictly specify the position where the conductive tape is attached, there is a drawback that it is not suitable for mass production. Further, Japanese Patent Laid-Open No. 7-326922 proposes a structure in which a non-metal spacer is inserted between metal plates and the position of insertion is changed to tune the antenna characteristics.

However, the characteristics of the antenna are very sensitive to the distribution of the dielectric constant between the metal plates, so that the spacers can be precisely formed on only a part of the spacers between the metal plates as disclosed in Japanese Patent Laid-Open No. 7-326922. It must be said that it is almost impossible to reproduce stable antenna characteristics in mass production with the method of positioning and installing in.
The antenna disclosed in Japanese Patent Laid-Open No. 7-326922 is an inverted F antenna assuming that most of the space between the metal plates is filled with air, and most of the space between the metal plates is a dielectric. The structure is different from that of the flat patch antenna to be filled.

An object of the present invention is to solve the above problems and to provide an antenna for a portable wireless device which is a flat patch antenna which can be easily manufactured and tuned at low cost.

[0007]

The present invention has the following means to solve the above problems. An antenna for a portable wireless device according to claim 1 of the present invention is a radiation plate formed of a metal plate, a metal foil, a conductive film or the like, and a metal plate and a metal foil provided in parallel to face the radiation plate. , A ground plate formed of a conductive film or the like, and a portable wireless device antenna comprising a planar patch antenna provided with a resin dielectric plate disposed between the radiation plate and the ground plate, It is characterized in that the dielectric plate is provided with a tuning-out recess for tuning, which is 50% or less of the volume obtained by multiplying the average thickness of the dielectric plate by the area of the radiation plate.

In the antenna for portable radio equipment according to claim 2 of the present invention, the filleting recess of the dielectric plate is a hole, a groove, a notch or a combination thereof, and the filleting recess is a side surface of the dielectric plate. It is characterized by having an opening.

According to the portable radio device antenna of claim 1 of the present invention, since the dielectric plate is provided with a tuning-out recess for tuning, the antenna can be adjusted by changing the depth of the removal recess. Adjust the characteristics of. The tuning-in concave portion is filled with air and has a lower dielectric constant than the dielectric plate. Increasing the thickness of the tuning-recessing recess reduces the effective permittivity between the antenna radiation plate and the ground plate, thus increasing the resonance frequency. Also,
Reducing this meat removal amount reduces the resonance frequency.
Therefore, it is possible to change the resonance frequency of the antenna by changing the depth of the tuning recess for tuning. Note that the tuning-in concave portion has a different permittivity as compared with the surrounding portion, so that the electromagnetic field distribution between the radiation plate and the ground plate of the antenna is disturbed.

As a result, the volume of the tuning-thickening recess is 5 times the volume obtained by multiplying the average thickness of the dielectric plate by the radiation plate area.
When it exceeds 0%, a phenomenon that the band of the antenna deteriorates is observed. Therefore, it is preferable that the tuning-thickening recess is 50% or less of the volume obtained by multiplying the average thickness of the dielectric plate by the radiation plate area. The tuning recess for recess provided in the dielectric is formed by a hole, a groove, a notch, or a combination thereof. There may be a plurality of fillet recesses in the dielectric.

According to the antenna for portable radio equipment of claim 2 of the present invention, since the fill-in recess is opened on the side surface of the dielectric plate, for example, the dielectric plate is subjected to the insert resin molding method using a resin molding die. In the case of manufacturing with, for example, a metal plate is preliminarily processed into a metal plate, placed in a resin molding die, and a molding block for forming a flesh-removing recess is provided. Since it is possible to change the depth of the antenna, it is possible to inexpensively obtain an antenna for a portable wireless device provided with a dielectric plate having a tuning recess for tuning. Further, for a dielectric plate having no flesh-removing recess, a flesh-removing recess is formed from a side surface of the dielectric plate to easily form a retreat-relieving recess. Can be obtained.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an antenna for a portable wireless device of the present invention will be described below in more detail with reference to FIGS.

(Embodiment 1) In FIG. 1, reference numeral 1 represents an embodiment of an antenna for portable radio equipment of the present invention. The portable wireless device antenna 1 includes a dielectric plate 2 made of resin.
And a radiation plate 3 formed of a metal plate, a metal foil, a conductive film or the like provided on one surface of the dielectric plate 2, and a radiation plate 3 that is parallel to the other surface of the dielectric plate 2 facing the radiation plate 3. And a ground plate 4 made of a metal foil, a conductive film, or the like. In FIG. 1, reference numeral 5 is a short-circuit portion that electrically connects the radiation plate 3 and the ground plate 4. Further, reference numeral 6 is a power source, which is connected to the radiation plate 3 and the ground plate 4 by a power supply line 7a and a power supply line 7b, respectively. The characteristic of the portable wireless device antenna 1 including the planar patch antenna of the present invention lies in the dielectric plate 2. That is, the dielectric plate 2 has a side surface 2a having a tuning recess 8 for tuning.

The portable radio device antenna 1 configured as described above is manufactured, for example, by the insert resin molding method as follows. In the resin molding die, a radiation block 3, which has been formed into a predetermined shape by sheet metal working in advance, a ground plate 4, and a molding block for molding a recess 8 for tuning are set at a predetermined position, It is manufactured by injecting a resin for the dielectric plate 2. At this time, if the position of the set of molding blocks for molding the tuning-removal recess 8 is adjustable, the depth of the manufactured tuning-removal recess 8 hole can be arbitrarily changed. .

In this way, a predetermined number of dielectric plates 2 having different depths of the tuning recesses 8 for tuning are collectively manufactured. The tuning can be easily achieved by selecting and using the one having a predetermined antenna characteristic when it is incorporated into the wireless device. That is, since the tuning-out recess 8 is filled with air, its dielectric constant is lower than that of the dielectric plate 2 itself. When the depth of the tuning-removal recess 8 is increased, that is, when the removal amount is increased, the radiation plate 2 and the ground plate 4 are increased.
Since the effective permittivity in between decreases, the resonance frequency increases.

Further, when the tuning-removal recess 8 is made shallow, that is, when the removal amount is reduced, the resonance frequency is reduced. Therefore, it is possible to change the resonance frequency of the portable wireless device antenna 1 formed of the planar patch antenna by changing the depth of the tuning-for meat removing concave portion 8. Table 1 shows the relationship between the depth of the tuning recess 8 and the antenna characteristic of the antenna 1 for a portable wireless device, which is formed by the above-described method and includes the planar patch antenna shown in FIG.

As can be seen from Table 1, the resonance frequency increases as the depth of the tuning recess 8 for tuning increases. Here, the tuning-out recess 8
Is less than 7 mm when the volume of the tuning recess 8 is within 40% of the volume obtained by multiplying the average thickness of the dielectric plate 2 by the area of the radiation plate 3. Is no different. In addition, when the depths of the recessed cavities 8 shown in Table 1 are 8 mm and 9 mm, the recessed cavities 8 are
Is more than 40% and within 50% of the volume obtained by multiplying the average thickness of the dielectric plate 2 by the area of the radiation plate 3.

[0018]

[Table 1]

However, when the depth of the flesh-relieving recess 8 exceeds 8 mm, that is, when the volume of the flesh-relieving recess 8 exceeds 40% of the volume obtained by multiplying the average thickness of the dielectric plate 2 by the area of the radiation plate 3. Since the VSWR band characteristic becomes narrow, it is preferable that the volume of the recessed portion 8 is within 50% of the volume obtained by multiplying the average thickness of the dielectric plate 2 by the area of the radiation plate 3. It is more preferably within 40%.

(Embodiment 2) In FIG. 2, reference numeral 11 shows another embodiment of the antenna for portable radio equipment, which is the planar patch antenna of the present invention. The portable wireless device antenna 11 includes a dielectric plate 2 made of resin, a radiation plate 3 provided on one surface of the dielectric plate 2, and a radiation plate 3 on the other surface of the dielectric plate 2 facing the radiation plate 3. Ground plates 4 provided in parallel
It is similar to the first embodiment in that The feature of the portable wireless device antenna 11 of the present embodiment is that the tuning-out recess 18 provided on the side surface of the dielectric plate 2 is used.
Has two holes 18a and 18b. The other configurations are the same as those in the first embodiment, and the same members are denoted by the same reference numerals and detailed description thereof is omitted.

Antenna 1 for portable radio device of the second embodiment
1 is manufactured as follows, for example. The metal foil attached to both surfaces of the resin dielectric plate 2 is etched into a predetermined shape to form the radiation plate 3 and the ground plate 4. Each of the antennas for portable radios 1 is separated by separating the substrate on which the radiation plate 3 and the ground plate 4 are formed.
Make a prototype of 1. A member required as a plane patch antenna is formed on the prototype of the portable radio device antenna 11 in a predetermined order to manufacture the portable radio device antenna. Since this antenna for portable radio does not have a tuning recess for tuning, a tuning recess for tuning is formed as follows. Two holes 18a, 18 of a tuning recess 18 provided on the side surface of the dielectric plate 2 for tuning.
b is formed, for example, by processing each with a precision drill to a predetermined depth. As described above, the portable wireless device antenna 11 having the tuning-removing recess 18 opened on the side surface 2a of the dielectric plate 2 is manufactured.

(Embodiment 3) In FIG. 3, reference numeral 21 shows another embodiment of the antenna for portable radio equipment, which is the planar patch antenna of the present invention. The portable wireless device antenna 21 includes a resin dielectric plate 2, a radiation plate 3 provided on one surface of the dielectric plate 2, and a radiation plate 3 on the other surface of the dielectric plate 2 facing the radiation plate 3. Ground plates 4 provided in parallel
It is similar to the first embodiment in that Also, the tuning-out recess 28 provided on the side surface of the dielectric plate 2 has two holes 28a and 28b, as in the second embodiment. The features of the portable wireless device antenna 21 of the present embodiment are two holes 28a of a tuning recess 28 provided on the side surface of the dielectric plate 2,
28b is in contact with the radiation plate 3. The other configurations are the same as those in the first embodiment, and the same members are denoted by the same reference numerals and detailed description thereof is omitted.

Antenna 1 for portable radio device of the third embodiment
1 is manufactured as follows, for example. The metal foil attached to both surfaces of the substrate made of the resin dielectric plate 2 is etched into a predetermined shape to form the ground plate 4. A dicing saw is used to make a cut of a predetermined width on the surface of the substrate facing the ground plate 4 to form a recess 2
Individual holes 28a and 28b are formed. Two holes 28a, 2
The radiating plate 3 formed separately by stamping metal plate processing or etching is attached to the surface on which 8b is formed with an adhesive. The above-mentioned substrate is cut off to make a prototype of each antenna 11 for portable radio equipment. The prototype of this portable radio device antenna 11 is formed with members required for a plane patch antenna in a predetermined order, and has a tuning-recessing concave portion 28 opened on the side surface 2a of the dielectric plate 2. The portable wireless device antenna 21 is manufactured.

[0024]

As described above, according to the antenna for portable radio equipment of claim 1 of the present invention, since the dielectric plate is provided with the fleshing recess for tuning, the fleshing recess is provided. The characteristics of the antenna are adjusted by changing the depth. That is, since the tuning-out recess for tuning is filled with air, it has a lower dielectric constant than the dielectric plate. Increasing the thickness of the tuning recess for recess reduces the effective permittivity between the antenna radiation plate and the ground plate.
The resonance frequency increases. Moreover, if the amount of meat removal is reduced, the resonance frequency is reduced. Therefore, it is possible to change the resonance frequency of the antenna by changing the depth of the tuning-up recessed portion. As a result, it is possible to provide an antenna for a portable wireless device that is a low-cost planar patch antenna that can be easily tuned.

According to the antenna for portable radio equipment of claim 2 of the present invention, since the flesh recess is opened to the side surface of the dielectric plate, the dielectric plate is subjected to the insert resin molding method using a resin molding die, for example. In the case of manufacturing with, the depth of the filleting recess can be easily changed by finely adjusting the molding block, so an antenna for a portable wireless device provided with a dielectric plate having a filleting recess for tuning can be inexpensively manufactured. Obtainable. Further, for a dielectric plate having no flesh-removing recess, a flesh-removing recess is formed from a side surface of the dielectric plate to easily form a retreat-relieving recess. Can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view and a front view showing an embodiment of an antenna for a portable wireless device of the present invention.

FIG. 2 is a perspective view showing another embodiment of the antenna for portable wireless device of the present invention.

FIG. 3 is a perspective view showing another embodiment of the antenna for portable wireless device of the present invention.

[Explanation of symbols]

 1 Antenna for portable wireless device consisting of planar patch antenna 2 Dielectric plate made of resin 3 Radiating plate 4 Ground plate 5 Short-circuiting part for connecting radiation plate and ground plate 6 Power supply 7a, 7b Feeding wire 8 Recessing recess for tuning

Claims (2)

[Claims] 1. A radiation plate formed of a metal plate, a metal foil, a conductive film, and the like, and a ground formed of a metal plate, a metal foil, a conductive film, and the like which are provided in parallel to face the radiation plate. An antenna for a portable wireless device comprising a plate and a planar patch antenna provided with a resin dielectric plate disposed between the radiation plate and the ground plate, wherein the dielectric plate is a dielectric plate. 50 times the volume obtained by multiplying the average thickness by the area of the radiation plate.
%, An antenna for a portable wireless device, which is provided with a flesh-recessing recess for tuning. 2. The portable radio device according to claim 1, wherein the filleting recess of the dielectric plate comprises a hole, a groove, a notch, or a combination thereof, and the filleting recess is opened on a side surface of the dielectric plate. For antenna.