JPH0918219A - Antenna attachment method and its structure - Google Patents

Abstract

PURPOSE: To improve the technique to attach an antenna unit to the main body case of a radio unit, to mechanically support an antenna element to the main body case and also to electrically connect the antenna element to the high frequency circuit of the main body of the radio unit, to improve the water proof of the main body case of the radio unit, and also to reduce the production cost and the attachment manhour of the antenna unit. CONSTITUTION: A λ/4 exciter 15 connected to the high frequency circuit of a radio unit is enclosed in a sealing case 11'. A λ/2 antenna element 12a is pivoted to a unit base 12d via a spindle 12b to form an antenna unit 12. Then the unit 12 is attached on the outer peripheral surface of the case 11' of the radio unit as shown by the arrows c, c' and c''. The exciter 15 and the element 12a are set opposite to each other over the wall of the case 11' and are electrostatically capacity coupled to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mechanically supports an antenna for a portable wireless device by a case of the portable wireless device and electrically connects the antenna to a high frequency circuit of the portable wireless device. The present invention relates to a mounting method and the mounting structure.

[0002]

2. Description of the Related Art Recent technical researches on mobile communication devices including portable telephones are directed to practical use of a digital cordless telephone system, which is commonly called a second generation cordless telephone. In this system, for example, 1.9 GHz
As described above, it is predicted that the frequency used will be twice as high as that of the conventional method. In view of such a tendency of technological development, an antenna element that resonates at λ / 2 in a method of supporting an antenna so as to stand and store and electrically connecting the antenna element to a telephone body of a mobile radio telephone,
Resonate at λ / 4 and couple the above antenna element to the feed line.
A matching exciter is provided, and the end of the antenna element on the side where the voltage is maximized and the open end of the exciter are coupled via a minute coupling capacitance, and the exciter is provided. A λ / 4 ground radiator is arranged at the connecting portion with the power supply line, and the antenna element is connected to the case of the communication device main body in the small electrostatic capacitance portion coupling between the antenna element and the exciter. Techniques have been proposed for supporting the shaft so as to be tiltable. According to the above configuration, the antenna element that resonates at λ / 2 is mechanically tilted with respect to the main body of the communication device, which is convenient for standing up and folding storage, and is electrically non-conductive. Since they are connected by contact, there is no risk of poor conduction due to poor contact. The above technology is
It is an invention created by the present inventor and already applied for by the present applicant (Japanese Patent Application No. 4-288948), and is hereinafter referred to as an invention of the prior application. FIG. 6 is an explanatory view of the basic principle of the invention of the above-mentioned prior application. As shown in (A), the λ / 2 antenna 1 is set up, and the lower end of the antenna 1 includes a matching circuit λ.
/ 4 Make the open sides of the exciter 2 face each other. Ia and Iex drawn by broken lines are current distribution curves, respectively. Although not shown, the voltage distribution state is inversely proportional to the current distribution, and the tendency of magnitude is opposite. In the above figure (A), λ
The fact that the current minimum portions of the / 2 antenna 1 and the λ / 4 exciter 2 face each other means that the voltage maximum portions face each other. In such a state, since the minute electrostatic capacitance C exists between the two, the high frequency signal of the wavelength λ is efficiently transferred from the exciter to the antenna. That is, they are electrically connected without contact. As shown in FIG. 6 (B), when the λ / 2 antenna 1 is tiltably supported by the support shaft 7, the λ / 2 antenna 1 can be used upright as indicated by an arc arrow u, and can be tilted down and accommodated as indicated by an arc arrow d. it can. Reference numeral 4 denotes a moving shaft cable for connecting a circuit (not shown) of the communication device and an antenna including the exciter 2. This configuration is established on the premise of the existence of an effective and reliable earth, but since a sufficient earth portion cannot be secured in the portable wireless device, the ground radiator 3 consisting of a λ / 4 ground wire is provided. Although the minute capacitance C varies depending on various conditions, a sufficient number of pF is usually sufficient, and even in the case of a quasi-microwave portable wireless device, it is 1 pF.
Is not required, so that there is no particular difficulty in specific means for forming this minute capacitance.

In order to further miniaturize the structure shown in FIG. 6 (B), it is effective to improve it as shown in FIG. 6 (C). That is, a zigzag type antenna element 5 in which the linear antenna 1 is repeatedly bent is configured and housed in an antenna case 6, and the antenna case 6 is supported by a support shaft 7 so as to be tiltable. (B) The λ / 4 exciter 2 shown in the figure is bent in a zigzag type to form a zigzag type exciter 2 ′, and the spindle 7 is connected to the open end thereof. If the support shaft 7 is opposed to and separated from the zigzag type antenna element 5 in the antenna case 6 without contacting with the zigzag type antenna element 5, a desired capacitance is obtained, and the zigzag type antenna element 5 and the exciter 2'are capacitively coupled. It

FIG. 7 shows the antenna support according to the invention of the prior application.
FIG. 4 is an exploded perspective view illustrating an embodiment of the connection structure, and is a substantially similar view in which a part of the reference numerals in FIG. 3 (A) in the accompanying drawings of the prior application is modified. The reference numeral 8 in FIG. 7 indicates an antenna unit including the antenna element 5 (see FIG. 6A), the exciter 2 ′, and the support shaft 7 described above, which is coaxial. The cable 4 is attached. The body case 9 is formed with a recess 9a having a negative outer peripheral shape of the antenna unit 8, and the antenna unit 8 is mounted so as to fill the recess 9a.

[0005]

The inventor of the present invention has created and applied for the invention of the above-mentioned prior application, and has carried out industrial mass production and practical tests. An antenna having VSWR performance suitable for a portable communication device is connected without requiring physical contact, and
It was confirmed that the folding storage and the upright use can be operated quickly and easily, and that it will be a great contribution to the future progress of digital cordless telephone technology, but there is room for further improvement as described below. It was confirmed.

Considering FIG. 7 showing the invention of the prior application as an example, when the antenna unit 8 is attached to the main body case 9, the coaxial cable 4 is inserted into a cable insertion hole 9b provided in the main body case 9, The connector 4a attached to the tip of the coaxial cable must be connected to a high frequency circuit (not shown) in the body case 9. Therefore, the cable insertion hole 9 provided in the main body case 9
There is a possibility that rainwater or the like may enter the body case from b, and the waterproofness is insufficient. Moreover, when the antenna unit 8 is attached to the main body case 9, it is necessary to insert the coaxial cable 4 into the cable insertion hole 9b and insert the connector 4a into a socket (hidden in the figure). The connector 4a can be inserted with one touch, but the connector 4a can be inserted without removing the back cover 9c of the main body case 9. Therefore, it is necessary to attach the back cover 9c after inserting the connector 4a. Is. In total, it takes a lot of time to attach the antenna unit 8. Moreover,
Since the manufacturing cost of coaxial cable with connector is high,
The price of antenna devices is rising.

The present invention has been made in view of the above-mentioned circumstances, and does not impair the advantages (excellent tuning characteristics / quick, easy storage, standing operation) of the invention of the prior application, and the main body case It is an object of the present invention to provide a high-performance antenna at a low price by completely waterproofing the main body case and improving the work of mounting the antenna unit on the main body case so that the work can be performed quickly and easily.

[0008]

Regarding the basic principle of the present invention created to achieve the above object, FIG. 6C showing an example of the invention of the prior application and one embodiment of the present invention. 2, which corresponds to the above, in the invention of the prior application, the antenna element 5, the antenna case (also referred to as an antenna cover) 6, and the support shaft 7 which are surrounded by an imaginary line in FIG. The antenna unit 8 including the exciter 2 ′ and the ground radiator 3 is configured, and the coaxial cable 4 is attached to the antenna unit 8. In comparison with this, according to the present invention, for example, as shown in FIG.
An antenna unit 12 'in which e is pivotally supported by a support shaft 12b on a base member 12d constitutes an exciter 15' installed in a case 11 '. The antenna element 12e and the exciter 15 'are capacitively coupled to each other across the wall of the case. Therefore, the present invention does not require a coaxial cable for connection. Therefore, it is not necessary to make a hole for inserting the coaxial cable in the case, and the work for attaching the coaxial cable is not necessary. A specific configuration of the method of the present invention based on the above principle will be described with reference to FIG. 1 corresponding to the first embodiment. An antenna is provided for a radio frequency circuit of a radio device housed in a synthetic resin case. In the method of electrically connecting the antennas and mechanically supporting and mounting the antenna by the above case, the base (1
The λ / 2 antenna element (12a) is rotatably supported with respect to 2d) to form the antenna unit (12), and the high frequency circuit (16) and λ are provided in the case (11) of the radio device.
/ 4 exciter (15) is installed, the base of the antenna unit is fixed to the outer peripheral surface of the case of the radio, and the vicinity of the feeding end of the λ / 2 antenna element and the open end of the λ / 4 exciter are fixed. And is capacitively coupled. Among the features mentioned above, the important points are (a) λ in the radio case
(2) The λ / 2 antenna element and the λ / 4 exciter are capacitively coupled to each other across the wall of the radio case by housing a / 4 exciter. The method of supporting the antenna element and the exciter The installation method is not necessarily limited. However, when carrying out the method of the present invention, the λ / 2 antenna element (12
Around the feeding end of a) is rotatably supported by a conductive support shaft (12b) with respect to a synthetic resin base (12d), and the shaft support and the λ / 4 exciter (15) are supported. When the capacitive coupling is performed by making the open end of the capacitor and the open end face each other across the wall of the case (11), the coupled capacitance does not change when the λ / 2 antenna element is rotated, and the coupled capacitance is Easy to control. Further, if the above-mentioned wireless device case is constructed in a hermetically sealed manner, there is no risk of water being infiltrated from the antenna mounting portion, so that complete waterproofness can be obtained. Further, a metal film is formed on one surface of the substrate (13) constituting the high frequency circuit (16) to form a base plate (1
4) is formed and a part of the metal film is etched to form a zigzag type λ / 4 exciter (15), and when the substrate is fixed to the case (11), the λ / 4 The exciter can be easily and compactly constructed, and the λ /
4 The exciter can be easily and reliably positioned with respect to the case.

Further, the antenna mounting structure of the present invention constructed based on the principle of the present invention described above with reference to FIG. 6C and FIG. 2 is a radio housed in a synthetic resin case. In the structure in which the antenna is electrically connected to the high-frequency circuit of the machine and the antenna is mechanically supported and attached by the case, the base member (12
An antenna unit (12) in which a λ / 2 antenna element (12a) is rotatably supported with respect to d), a high frequency circuit (16) and a λ / 4 exciter (15) are housed and installed. It is equipped with a radio case (11),
The base member is attached to the outer peripheral surface of the case, and is provided near the feeding end of the λ / 2 antenna element and the λ /
4 is characterized in that a capacitance is formed between it and the open end of the exciter. Among the features described above regarding the antenna mounting structure of the present invention, important points are (a) that an antenna unit in which an antenna element is supported by a base member is configured, and (b) an exciter is housed in a case. That (c) the antenna unit is attached to the outer peripheral surface of the sealed case, and (d) that electrostatic capacitance is formed between the antenna unit and the exciter,
The support structure of the antenna element and the relationship between the support member and the capacitance are not necessarily limited, but the λ / 2 antenna element (12a) is fixed to the support shaft (12b) made of a conductive material and the support shaft is fixed. The base member (12
d) is rotatably supported, and the support shaft separates the wall of the case (11) from the λ / 4 exciter (15).
The λ / 2 antenna element forms a stable coupling capacitance with the open end of the λ / 4 exciter through the support shaft when facing the open end of the antenna element (when the antenna element rotates). Does not change the capacitance).

As the λ / 2 antenna element in the antenna mounting structure according to the present invention, any one of a linear antenna, a plate antenna, a helical antenna, and a zigzag antenna can be selected and applied. The linear antenna can be made small and inexpensive, the plate antenna can be made thin, which is convenient for supporting by a support shaft, and the helical antenna is effective for shortening the length dimension. The zigzag antenna is effective for shortening the length and can be made thin. If these antenna elements are covered with a synthetic resin antenna cover, they can be protected mechanically and chemically without adversely affecting the electrical characteristics. This antenna cover rotates with the λ / 2 antenna element.

If the rotation of the antenna cover is moderated by the ball spring means, the antenna can be held securely in the upright state and the stored state. When the λ / 4 exciter is formed as a pattern on a high frequency circuit board, the manufacturing cost is low and the positioning with respect to the case is easy.

[0012]

When the antenna mounting structure is constructed according to the antenna mounting method in the means for attaining the above-mentioned object, the high frequency circuit and the λ / 4 exciter are housed in the case of the radio, and the high frequency circuit and the antenna element are housed. Since there is no need for mechanical contact to connect with the wireless device case, there is no need to insert a coaxial cable by making a through hole in the wall of the wireless device case. As described above, since it is not necessary to form a through hole in the radio device case, it is possible to make the waterproof property completely, and it is not necessary to insert the coaxial cable into the through hole or insert the connector of the coaxial cable. Therefore, the work of mounting the antenna can be performed quickly and easily. Further, since the work related to the coaxial cable is not required, not only the number of man-hours required for assembling can be reduced, but also the human error caused by the work does not occur, and the reliability of the entire radio device is improved. All in all, the high-performance, high-quality antenna is manufactured and supplied at low cost, which is a great contribution to the development of the portable wireless device industry. If a sealed case is used as the radio case, a completely watertight portable radio can be constructed. However, even if a non-sealed case is used, the waterproofness is improved and the drip-proof portable radio is constructed. Suitable for

In carrying out the present invention, the vicinity of the feeding end of the λ / 2 antenna element is rotatably supported by a conductive support shaft with respect to a base made of synthetic resin, and the support shaft and λ / 4 When the open end of the exciter is made to face each other across the wall of the case made of synthetic resin, an electrostatic capacitance is formed by using the wall of the case as a dielectric, and this electrostatic capacitance value causes the λ / 2 antenna element to rotate. However, the antenna performance is stable because it hardly changes. If the λ / 2 antenna element is a linear antenna, it can be manufactured at low cost. Further, if it is configured by a plate-shaped antenna, the plate-shaped antenna can be reliably and easily supported by the support shaft, and can be formed into a thin member. When the λ / 2 antenna element is composed of a helical antenna, the mechanical length dimension can be shortened as compared with a linear antenna or a plate antenna. In addition, if the zigzag antenna is used, the mechanical length can be shortened, and the zigzag antenna can be formed to be as thin as the plate antenna. Λ above
When the / 2 antenna element is covered with a synthetic resin antenna cover, the λ / 2 antenna element can be mechanically protected (deformation, breakage prevention, etc.) and chemically protected (rust prevention, etc.). In addition to the above, the operation of raising or falling the λ / 2 antenna element with a fingertip becomes easy, and the design is improved. Further, when the above-mentioned synthetic resin antenna cover is provided, this antenna cover can be rotatably supported by the support shaft, and λ /
There is a great degree of design freedom regarding the support of the two antenna elements,
A large mechanical safety factor can be taken. Moreover, when the rotation of the antenna cover is moderated by the ball spring means, the antenna can be reliably held in the upright (used) state and the overturned (stored) state.

In carrying out the above-mentioned structure, if a metal film is formed on a substrate for a high frequency circuit and a λ / 4 exciter is formed by etching, a manufacturing cost is low and
Advantageously, the λ / 4 exciter is automatically positioned relative to the case via the substrate. Thus, λ / 4
The configuration in which the exciter is provided on the high-frequency circuit board is possible on the assumption that the λ / 4 exciter is housed and installed in the case of the radio device main body in the basic configuration of the present invention. This is a configuration that cannot be applied even if the exciter 2'is incorporated in the antenna unit 8 as in the invention of the prior application (see FIG. 6C).

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, referring to FIGS.
An embodiment of the present invention will be described. FIG. 1 shows an embodiment of an antenna mounting structure configured by applying the antenna mounting method according to the present invention, in which a cross-sectional view taken along a plane passing through a support shaft of an antenna element and a BB cross-sectional arrow view thereof are drawn. FIG. 1
Reference numeral 1 denotes a closed case made of synthetic resin, in which a substrate 13 on which electronic components for a high frequency circuit 16 are mounted is fixed. The base plate 14 is formed by copper plating on the back side of the substrate 13 as viewed from the high frequency circuit 16.
Then, a zigzag λ / 4 exciter 15 is formed by etching a part of the copper plating. In FIG. 1, the cross section appears in FIG. The overall shape will be described later with reference to FIG.

Reference numeral 12a designates a zigzag type λ / 2 antenna element, and the left end of the figure in FIG. 1 (B) is the feeding end,
The right end is the open end. A metal support shaft 12b is fixed through the vicinity of the feeding end of the λ / 2 antenna element 12a so as to be electrically connected. The λ / 2 antenna element 12a is insert-molded in an antenna cover 12c made of synthetic resin, and both ends of the support shaft project from the antenna cover 12c. Reference numeral 12d is a base member that constitutes the antenna unit 12, is formed of a synthetic resin material, and rotatably supports the support shaft 12b. This allows
The λ / 2 antenna element 12a is rotatably supported with respect to the unit base 12d, and the λ / 2 antenna element 12a, the support shaft 12b, the antenna cover 12c, and the unit base 12d serve as an antenna unit 12.
Is configured.

The antenna unit 12 is attached to the outer peripheral surface of the hermetically sealed case 11. In FIG. 1B, when the antenna cover 12c in which the λ / 2 antenna element 12a is embedded is rotated by 90 degrees in the direction of the circular arc arrow a with a fingertip, the antenna cover upright position 12c 'drawn by a virtual line is obtained. The λ / 2 antenna element 12a also stands up and is in use. A ball spring 17 is partially embedded in the unit base 12d, and a part of the ball projects toward the antenna cover 12c. The antenna cover 12c is formed with a recess that engages with the ball, and when the antenna cover 12c is rotated in the direction of the arrow a to the standing position 12c 'shown by an imaginary line, and when the arrow b is shown. When the ball is rotated in the direction to the storage position drawn by the solid line, the concave portion and the ball are engaged with each other, so that the rotation is moderated. As a result, the λ / 2 antenna element 12a embedded in the antenna cover 12c is elastically locked to rotate in the upright / used state and the fall / stored state, and holds its position.

In carrying out the present invention, the feeding end of the λ / 2 antenna element 12a and the open end of the λ / 4 exciter 15 are opposed to each other with the wall of the hermetically sealed case interposed therebetween without interposing another conductive member. Although it is possible to form a capacitance by
When the electrostatic capacitance is formed through the conductive support shaft 12b as in the present embodiment (FIG. 1), the position of the support shaft 12b does not change even if the λ / 2 antenna element 12a rotates, so that the electrostatic capacitance is increased. The capacitance value is kept constant and the electrical performance is stable. Since the user of the portable radio does not always stand up the antenna correctly and sometimes uses the antenna in a half-raised state, the capacitance value is irrespective of the rotation angle of the λ / 2 antenna element 12a. Being constant is one of the desirable properties.

When carrying out the present invention, it is possible to construct the λ / 4 exciter separately from the substrate 13 of the high frequency circuit and install it in the closed case 11. However, as in this embodiment, the substrate 1
If the λ / 4 exciter 15 that is etched on 3 is configured, the manufacturing cost of the λ / 4 exciter is low, and when the substrate 13 is mounted at a predetermined position in the sealed case 11, the Since the λ / 4 exciter 15 provided above is automatically positioned, the number of man-hours required for the assembling work is reduced, and the risk of human error regarding the mounting position is reduced.

In carrying out the present invention, it is possible to have a structure in which the λ / 2 antenna element 12a is exposed without being covered with an antenna cover. However, by embedding the λ / 2 antenna element 12a in the antenna cover 12c as in this embodiment, the reinforcing effect and the protective effect of the antenna element can be obtained. That is, as shown in the cross-sectional view of FIG. 1A, the zigzag λ / 2 antenna element 12a is a thin member and is not likely to be deformed or broken when it collides with an external obstacle. However, if the antenna cover 12c made of synthetic resin is used as in the present embodiment, there is no fear of being bent or bent under normal use conditions. In particular, as shown in FIG. 1A, the support shaft 12 in this example is
b supports the λ / 2 antenna element 12a via the antenna cover 12c. If the antenna cover 12c is omitted in this embodiment, it is not easy to rotatably support the λ / 2 antenna element 12a by the support shaft 12b.

FIG. 2 shows an embodiment similar to the embodiment shown in FIG. 1 described above, and is a perspective view showing a state before the antenna unit is mounted in the closed case. It is the figure which added. The antenna unit 12 of this example has the same components as those in the above-described embodiment. The closed case 11 'of this example is a member corresponding to the closed case 11 in the above-mentioned example, and the width dimension thereof is L.
_Set to ₁ . The size L ₁ and the length L ₂ of the antenna unit 12 are set to be substantially the same. Then, the outer shape of the antenna unit (that is, the outer shape of the unit base 12d) is provided near the upper end of the closed case 11 '.
A concave portion 11a having a negative shape is formed. This concave portion is for mounting the antenna unit 12, and when the antenna unit 12 is attached to the closed case 11 'as shown by arrows c, c', c ", the concave portion is just compensated and the entire communication device is covered. The outer shape is adjusted. Here, what is related to the electrical performance is that the mounting position of the antenna unit 12 is set near the upper end of the sealed case 11 '. Even if the airtight case 11 is gripped in the palm, the antenna part is not wrapped in the palm and the electric performance is not affected.
In particular, there is a practical merit of not being affected by the palm when waiting for an incoming call in the stored state with the antenna inverted.

FIG. 3 is a table showing the results of measuring the directional characteristics / gain of the antenna in the above embodiment at 1.9 GHz, (A) showing the antenna standing up and (B) storing it. (C) is a vertical plane front-back pattern added to explain the polar coordinates shown in the above chart. The antenna gain when standing up is about 0 dBd, which is a high gain, and the antenna gain when stored is about -3 d.
It is understood that it is Bd and can be used even in the stored state depending on conditions. FIG. 4 shows S in the above embodiment.
The WR graph is shown, (A) shows the standing time and (B) shows the stored time. 1.9G especially when standing up
It is understood that the excellent wide band property is exhibited in the vicinity of Hz. FIG. 5 shows an embodiment different from the above, and is a cutaway two-side view corresponding to FIG. 1 in the embodiment. The difference from the above embodiment is that the zigzag λ / 2 antenna element 12a is replaced by a plate-shaped λ / 2 antenna element 12e. The plate-shaped antenna element has the disadvantage that the mechanical length is longer when the electric length is the same as compared with the zigzag-shaped antenna element, but the structure is simple and the cost is low. In the embodiment of the present invention, the L-shaped rising portion 12f and the support shaft 12b of the plate-shaped λ / 2 antenna element 12e.
Also helped extend the electrical length, so 1.9 GHz
The antenna cover length dimension L ₃ in the case of being configured to resonate was 50 mm. This value has a sufficient practical value as a tip-over antenna mounted on a portable telephone.

Although not shown, the plate-like λ / shown in FIG.
The two-antenna element can be replaced by a linear antenna. The linear antenna has a similar operation principle and a similar electrical characteristic to the plate antenna. When a linear antenna is used, the antenna cover 12c can be compared to a plate antenna.
Although the dimension H shown in FIG.
It is more difficult to connect with a plate antenna. Although not shown, the zigzag type λ / in the embodiment shown in FIG.
The two antenna element 12a may be replaced with a helical antenna element. Although the illustrated dimension W of the antenna cover 12c is increased by using the helical antenna element, the electrical characteristics equivalent to or higher than those of the zigzag antenna can be obtained.

In FIG. 2 described above, since the λ / 4 zigzag exciter 15 is formed on the substrate and is housed together with the substrate in the closed case 11 'as described above,
In this figure, it is drawn with a hidden line. Further, since the λ / 2 zigzag antenna element 12a is covered with the antenna cover 12c, it is drawn with a hidden line. As described above, since the main electrical constituent members of this embodiment are protected by the synthetic resin member, there is no risk of being damaged by external force or being wet by raindrops and rusting. In particular, λ
The / 4 zigzag type exciter is housed in the sealed case 11 ', and the sealed case 11' has no hole for inserting the coaxial cable, so that the waterproofness is perfect. Since the electrical connection between the λ / 4 exciter and the λ / 2 antenna element 12a is performed in a contactless manner by capacitive coupling, the antenna mounting work is extremely simple, and the antenna unit 12
Since the unit base 12d is simply attached in conformity with the unit mounting recess 11a of the hermetically sealed case 11 ', it can be carried out quickly and easily without requiring special skill.

[0025]

When the antenna mounting method according to the present invention is applied and the antenna mounting structure according to the present invention is applied, the high frequency circuit and the λ / 4 exciter are housed in a sealed case, and the high frequency circuit and the antenna element are housed. Since there is no need for mechanical contact to connect with, it is not necessary to insert a coaxial cable through a through hole in the wall of the hermetically sealed case. As described above, since it is not necessary to make a through hole in the sealed case, it is possible to make the waterproof property completely, and it is not necessary to insert a coaxial cable into the through hole or insert a connector of the coaxial cable. Therefore, the work of mounting the antenna can be performed quickly and easily. Further, since the work related to the coaxial cable is not required, not only the number of assembling steps can be reduced, but also the human error caused by the work does not occur, and the reliability of the entire radio device is improved. All in all, the high-performance, high-quality antenna is manufactured and supplied at low cost, which is a great contribution to the development of the portable wireless device industry. In carrying out the present invention, a conductive support shaft rotatably supports a base made of synthetic resin in the vicinity of a feeding end of the λ / 2 antenna element, and the support shaft and a λ / 4 exciter. When the open end of the case is made to face each other across the wall of the synthetic resin case, a capacitance is formed with the wall of the case as a dielectric, and this capacitance value is maintained even if the λ / 2 antenna element rotates. The antenna performance is stable because it hardly changes. If the λ / 2 antenna element is a linear antenna, it can be manufactured at low cost. Further, if it is configured by a plate-shaped antenna, the plate-shaped antenna can be reliably and easily supported by the support shaft, and can be formed into a thin member. When the λ / 2 antenna element is composed of a helical antenna, the mechanical length dimension can be shortened as compared with a linear antenna or a plate antenna. In addition, if the zigzag antenna is used, the mechanical length dimension can be shortened, and the zigzag antenna can be made as thin as the plate antenna. When the λ / 2 antenna element is covered with an antenna cover made of synthetic resin, the λ / 2 antenna element can be mechanically protected (deformation, breakage prevention, etc.) and chemically protected (rust prevention, etc.). In addition to the above, it becomes easy to operate the λ / 2 antenna element to stand up or down with a fingertip,
It also improves the design. Further, when the above-mentioned synthetic resin antenna cover is provided, the antenna cover can be rotatably supported by the support shaft, and the degree of freedom in designing the support of the λ / 2 antenna element is large, and mechanical safety is ensured. The coefficient can be large. Moreover, when the rotation of the antenna cover is moderated by the ball spring means, the antenna can be reliably held in the upright (used) state and the overturned (stored) state.

When the above-mentioned structure is carried out, when a metal film is formed on a substrate for a high frequency circuit and a λ / 4 exciter is formed by etching the metal film, the manufacturing cost is low and
Advantageously, the λ / 4 exciter is automatically positioned relative to the case via the substrate. Thus, λ / 4
The configuration in which the exciter is provided on the high-frequency circuit board is possible on the assumption that the λ / 4 exciter is housed and installed in the case of the radio device main body in the basic configuration of the present invention. This is a configuration that cannot be applied even if the exciter 2'is incorporated in the antenna unit 8 as in the invention of the prior application (see FIG. 6C). Summarizing the above, the main effects of the basic configuration of the present invention are that it is possible to completely waterproof the radio body case, and to perform the antenna unit mounting work quickly and easily. This is a significant reduction in manufacturing cost due to the fact that it has become available.

[Brief description of the drawings]

FIG. 1 shows an embodiment of an antenna mounting structure configured by applying an antenna mounting method according to the present invention, and shows a sectional view taken along a plane passing through a support shaft of an antenna element and a BB sectional arrow view thereof. It is the two-sided drawing drawn.

FIG. 2 shows an embodiment similar to the embodiment shown in FIG. 1 described above, and a perspective view depicting a state before the antenna unit is mounted in a sealed case is accompanied by an arrow and a dimensional symbol indicating the assembling work. It is a figure.

FIG. 3 is a table showing the results of measuring the directional characteristics / gain of the antenna in the above embodiment at 1.9 GHz,
(A) depicts the antenna standing up, (B) depicts the retracted state, and (C) is a vertical plane front-back pattern added to explain the polar coordinates shown in the above chart.

FIG. 4 shows a SWR graph in the above embodiment,
(A) shows the standing time and (B) shows the stored time.

FIG. 5 is a cutaway two-view drawing showing an embodiment different from the above and corresponding to FIG. 1 in the embodiment.

FIG. 6 is an explanatory view of the principle of the invention of the earlier application (Japanese Patent Application No. 4-288948), in which an auxiliary line, a symbol and a leader line are added to FIG. It is a similar figure.

FIG. 7 is an exploded perspective view showing a structure for supporting and connecting an antenna according to the invention of the prior application, which is substantially the same as the reference numeral of FIG. It is a similar figure.

[Explanation of symbols]

1 ... Linear antenna, 2, 2'exciter, 3 ... Ground radiator, 4 ... Coaxial cable, 5 ... Zigzag type antenna element, 6 ... Antenna case, 7 ... Spindle, 8 ... Antenna unit, 9 ... Main body case, 9a ... Recessed portion, 9b ... Cable insertion hole, 9c ... Back cover, 11, 11 '... Sealed case, 11a
... recesses, 12 ... antenna unit, 12a ... λ / 2 antenna element, 12b ... spindle, 12c ... antenna cover, 1
2d ... Unit base, 13 ... Substrate, 14 ... Main plate, 15
... λ / 4 zigzag exciter, 16 ... high-frequency circuit.

Claims (13)

[Claims] 1. A method of electrically connecting an antenna to a radio frequency circuit of a radio device housed in a synthetic resin case, and mechanically supporting and mounting the antenna by the case, comprising: The λ / 2 antenna element (12a) is rotatably supported with respect to the base (12d) of the unit to form the antenna unit (12), and the high frequency circuit (16) and the high frequency circuit (16) are provided in the case (11) of the radio device. A λ / 4 exciter (15) is installed, the base of the antenna unit is fixed to the outer peripheral surface of the case of the radio device, and the vicinity of the feeding end of the λ / 2 antenna element and the release of the λ / 4 exciter. A method for mounting an antenna, characterized in that the end and the end are capacitively coupled. 2. The antenna mounting method according to claim 1, wherein the case (11) of the wireless device is formed in a hermetically sealed type. 3. The λ / 2 antenna element (12a) is rotatably supported by a conductive support shaft (12b) in the vicinity of a feeding end thereof with respect to a synthetic resin base (12d). The spindle and the open end of the λ / 4 exciter (15),
The antenna mounting method according to claim 1 or 2, wherein the case (11) is opposed to the wall of the case (11) with a wall therebetween to perform capacitive coupling. 4. A base plate (1) formed by forming a metal film on one surface of a substrate (13) constituting the high frequency circuit (16).
4) is formed and a part of the metal film is etched to form a zigzag λ / 4 exciter (15), and the substrate is fixed to the case (11). The antenna mounting method according to any one of claims 1 to 3. 5. A structure in which an antenna is electrically connected to a radio frequency circuit of a radio device housed in a case made of synthetic resin, and the antenna is mechanically supported and attached by the case, With respect to the base member (12d), the λ / 2 antenna element (1
2a) includes a rotatably supported antenna unit (12) and a radio case (11) in which a high frequency circuit (16) and a λ / 4 exciter (15) are housed and installed. The base member is attached to the outer peripheral surface of the case, and the vicinity of the feeding end of the λ / 2 antenna element and the λ /
4. An antenna mounting structure characterized in that a capacitance is formed between the exciter and the open end of the exciter. 6. The antenna mounting structure according to claim 5, wherein the case (11) of the radio is a closed case. 7. The λ / 2 antenna element (12a).
Are fixed to a support shaft (12b) made of a conductive material and are rotatably supported by the support shaft with respect to a base member (12d) made of synthetic resin.
The antenna mounting structure according to claim 5 or 6, wherein the antenna mounting structure faces the open end of the λ / 4 exciter (15) across the wall of 1). 8. The antenna mounting structure according to claim 5, wherein the λ / 2 antenna element is a helical antenna element. 9. The antenna mounting structure according to claim 5, wherein the λ / 2 antenna element is a zigzag type antenna element. 10. A recess having a shape in which a part of the outer shape of the base member (12d) of the antenna unit (12) is made negative is formed near the upper end of the case (11) of the radio device. The base member is fixed to the recess, and the base member is fixed to the recess.
The antenna mounting structure according to any one of 1. 11. The λ / 2 antenna element is embedded in a synthetic resin antenna cover (12c), the support shaft (12b) penetrates the antenna cover, and both ends thereof are formed into the base. The antenna mounting structure according to any one of claims 7 to 10, which is rotatably supported by a member (12d). 12. A ball spring means (17) is partially embedded in the base member (12d) so that a ball portion is projected, and the antenna cover (12) is provided.
c) is formed with a recess for engaging the ball,
12. The antenna mounting structure according to claim 11, wherein the rotation of the antenna cover in which the / 2 antenna element is embedded is provided with a moderation. 13. A base film (14) is formed by depositing a metal film on one side of a substrate (13) on which electronic components for a high frequency circuit are mounted, and a part of the metal film is etched. To form a zigzag type λ / 4 exciter (15), and the above-mentioned substrate is provided in the sealed case (1).
1) Fixed inside, wherein the open end of the λ / 4 exciter is opposed to the support shaft (12b) through a wall of a hermetically sealed case. Item 12
The antenna mounting structure according to any one of 1.