JP2003298329A - Compact low-profile antenna and its composition method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further make narrower thickness dimensions without losing high- gain performance and wideband characteristics that are advantages in a compact low-profile antenna regarding a non-published prior application (patent application number 2001-245430) by further improving the compact low-profile antenna. <P>SOLUTION: An L-shaped antenna element 2 resonating by λ/4 is formed along adjacent two sides, namely long and short sides 1a and 1b, of a slender rectangular board, an exciter 3 resonating by λ/4 is formed on the same board 1, and the antenna element 2 is coupled with the exciter 3 by minute capacitance (c). Additionally, the board 1 is vertically fixed to a slender ground plate 7, and an end at the short side of the antenna element 2 is connected to and is continuous to the ground plate 7 by solder 4. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device which is remarkably shorter than a wavelength λ of radio waves to be transmitted / received, is thin and small, and has a high gain and a wide band property. It relates to a configuration method.

[0002]

2. Description of the Related Art An antenna for transmitting and receiving radio waves of several hundred megahertz to several gigahertz, which is very small and has high performance, has a structure shown in FIG. This antenna is disclosed in Japanese Patent Application No. 2001-245430.
It is an unknown invention (hereinafter referred to as an unknown prior application) filed separately as An antenna pattern 6 that resonates at λ / 4 is formed on the substrate 5, and a part thereof has a zigzag shape 6a. An exciter pattern 12 that resonates at λ / 4 is also formed on the substrate 5 and is connected to the core wire of the coaxial cable 10. This kind of antenna can sufficiently function on the premise of the existence of a good ground, and in the invention of this prior application, the metal frame 11 acting as a ground plate is an essential constituent member,
The substrate 5 and the flat plate-shaped portion 11a of the frame are held in parallel by the standing wall-shaped portion 11b that is integrally provided therewith. Reference numeral 13 is a mounting screw, and 5a is a hole for inserting the mounting screw. The antenna thus configured has a small size and a low attitude, has a sufficiently high gain as an antenna for, for example, a portable wireless communication device or a wireless LAN, and has a wide tuning frequency band.

The evaluation of a low-profile small antenna is not simple because it varies depending on the purpose of use and the conditions of use. However, the antenna according to the previously unknown invention shown in FIG. There is no doubt that it is one of the best in. However, these days, the progress of electronic technology, especially micro-fabrication, is remarkable. As a result, antennas, which are related devices, are required to be smaller and have higher performance. The present invention has been made in view of the above circumstances, and further improves the technology according to the invention of the previously unknown prior art shown in FIG. 6 to impair high gain and wide bandwidth equivalent thereto. Instead, the width dimension W is to be further shortened. However, since this type of antenna can be put to practical use in various postures, fixed concepts such as height dimension and width dimension cannot be applied, but the dimension L shown in the figure is taken as the length and the thickness is reduced. To do.

[0003]

The basic principle of the present invention created in order to achieve the above-mentioned object will be outlined below with reference to FIG. 1 corresponding to one embodiment thereof. That is, in order to further improve the low profile small antenna (Japanese Patent Application No. 2001-245430) according to the prior application, which is not known, to further reduce the thickness dimension without impairing the advantages of high gain performance and wide band characteristics. The L-shaped antenna element 2 resonating at λ / 4 is formed along two adjacent sides (that is, the long side 1a and the short side 1b) of the elongated rectangular substrate, and the exciter 3 resonating at λ / 4 is formed. Formed on the same substrate 1, the antenna element 2 and the exciter 3 are coupled by a minute electrostatic capacitance c. Further, the substrate 1 is fixed vertically to the elongated ground plate 7, and the end of the antenna element 2 on the short side is connected to the ground plate 7 by the solder 4 for conduction.

Based on the above-mentioned principle, the antenna according to the invention of claim 1 is formed along two adjacent sides of a substrate (1) having a rectangular shape (see FIG. 1) or an elongated shape similar thereto. Approximately L-shaped conductive pattern, λ / 4
Λ / 4 antenna element (2) that resonates at λ / 4, and an exciter (3) that resonates at λ / 4 installed near the end of the substrate opposite to the short side where the λ / 4 antenna element is formed. ) And a ground plate (7), and a long side of the substrate on the side where the antenna element is not formed is brought into contact with the surface of the ground plate so that the substrate and the ground plate are perpendicular to each other. And the end of the conduction pattern on the short side is connected to the ground plate for conduction, and the tip of the conduction pattern on the long side is opposed to and separated from the output end of the exciter. It is characterized by forming a capacitance (c). When the invention of claim 1 described above is applied, the thickness of the low-profile small antenna is reduced to the same extent as the width of the ground plate by making the ground plate elongated. In addition, a high gain and a wide band property equivalent to those of the invention (Japanese Patent Application No. 2001-245430) according to an unknown invention can be obtained, and the manufacturing cost is low.

The structure of the antenna according to the invention of claim 2 is as follows:
In addition to the constituent features of the invention of claim 1, the above λ / 4
The exciter that resonates at is constituted by a zigzag-shaped conduction pattern formed on the surface of the substrate, or a parallel conduction pattern in which inclination angles with respect to the long sides are different from each other on the both sides of the substrate It is characterized in that it is formed, and the end portion of the conduction pattern on the front side and the end portion of the conduction pattern on the back side are connected and conducted so as to penetrate each other through the substrate. When the invention of claim 2 described above is applied, since the exciter is configured by the conduction pattern, it is more suitable for industrial production and highly accurate than configuring the exciter separately (for example, by using a wire). The exciter can be constructed at low cost. In particular, the capacitance value can be precisely regulated, and the antenna performance can be made uniform.

The structure of the antenna according to the invention of claim 3 is as follows:
In addition to the constituent features of the invention of claims 1 and 2 (see FIG. 1), the outer conductor (10 a) of the coaxial cable is connected to the ground plate, and the core wire (10 b) of the coaxial cable is connected. Is connected and conducted to the input end of the exciter (3), and a coaxial cable connector is attached to the other end of the coaxial cable. According to the invention of claim 3 described above, when the antenna device part is manufactured and supplied by a specialized manufacturer,
The antenna device has marketability as one assembly so that it is convenient for radio manufacturers to purchase and use it. Especially, the antenna device is attached to a separately manufactured radio device. The work to do can be performed quickly and easily.

The structure of the antenna according to the invention of claim 4 is as follows:
In addition to the constituent features of the invention of claims 1 to 3 (see FIG. 2), a wide portion protruding toward the ground plate (7) at one or a plurality of portions of the long side (1c) of the substrate (1). Are provided to form the ridges (1d, 1e) or the protrusions (1f), while the gland plate (7) is provided with slot holes (7a, 7b) fitted to the ridges or A rectangular hole (7c) that fits into the projection is formed, and the parallelism and perpendicularity between the substrate and the ground plate are restricted by the fitting of the fitting portions. According to the fourth aspect of the invention described above, the convex portion formed on the substrate and the concave portion formed on the ground plate are fitted to each other to ensure the fixation of both members.
It is easy to position the parallelism of both members with high accuracy.

The structure of the antenna according to the invention of claim 5 is as follows:
In addition to the constituent features of the invention of claim 4 (see FIG. 3),
A cut and raised piece (1 g, 1 g, which is formed by cutting and raising the ground plate (7) along the edge of the slot (7a, 7b) parallel to the long side of the substrate.
1h) is formed, and the cut-and-raised pieces serve as positioning means for the substrate with respect to the ground plate. According to the invention of claim 5 described above, since the contact area between the concave portion of the substrate and the concave portion of the ground plate increases,
Positioning action becomes reliable.

The structure of the antenna according to the invention of claim 6 is in addition to the constituent features of the invention of claims 1 to 5 (see FIG. 3).
A leg-shaped projection (1j) is formed on at least one of both ends of the long side of the elongated substrate which is in contact with the ground plate, and the ground plate has the leg-shaped protrusion. An engaging gate-like engaging piece (7d) and an engaging piece (or an equivalent to a concave shape that closely fits the thickness dimension (t) of the substrate (1) described above. 7e) is formed. According to the invention of claim 6 described above, since both ends of the elongated substrate are fitted or sandwiched by the ground plate, both members can be positioned and fixed more reliably.

The structure of the antenna according to the invention of claim 7 is as follows:
In addition to the constituent features of the invention of claims 1 to 6 (see FIG. 1), the end portion on the short side of the substantially L-shaped conductive pattern formed along the two adjacent sides of the substrate is grounded. Soldered (4) to the board (7) and / or
In the vicinity of the end of the substrate on the side where the exciter (3) is provided, a small ground plate pattern (8) that is significantly smaller than the ground plate is formed adjacent to the ground plate, and The small board pattern is soldered (4) to the ground board. According to the seventh aspect of the invention described above, the fixing of the substrate and the ground plate is not only simple fitting, but also soldering makes it more reliable and strong. In addition, soldering the L-shaped antenna pattern and the ground plate ensures electrical connection continuity.

The structure of the antenna according to the invention of claim 8 is as follows:
In addition to the features of the invention of claims 1 to 7 (see FIG. 4), a λ / 4 consisting of a substantially L-shaped conductive pattern formed along two sides of the substrate (1) similar to the rectangle. Regarding the antenna element (2), the short side (1b) of the substrate
Is formed in a zigzag shape (2c). According to the invention of claim 8 described above, the short side of the substrate can be further shortened or the long side can be shortened, and the low-profile small antenna can be further downsized.

The structure of the invention method according to claim 9 is as follows (see FIG.
In a method of constructing an antenna for transmitting and receiving a radio wave of wavelength λ, on a surface of a rectangular or elongated substrate (1) similar to the rectangular shape, approximately L along the long side and the short side of the rectangle is provided. The antenna element (2) that resonates at λ / 4 is configured by the character-shaped conduction pattern, and is provided near the short side of the substrate, which is not along the antenna element,
An exciter (3) resonating at λ / 4 is provided, and a minute capacitance c is formed between the output end of the exciter and the input end of the antenna element, and the substrate (1 ) Is abutted and fixed to the ground plate (7) in a substantially vertical direction, and the end of the portion of the antenna element (2) along the short side of the substrate is connected to the ground plate for electrical conduction. Characterize. According to the method of claim 9 described above, since the antenna element having a great influence on the characteristics of the antenna is constituted by the conductive pattern, a large number of products (antennas) of uniform quality suitable for industrial mass production are provided. The antenna constructed by the method of the present invention has good performance and is small and lightweight.

According to a tenth aspect of the invention, in addition to the features of the ninth aspect of the invention method (see FIG. 2), the substrate (1) faces the ground plate (7). One or more protrusions (1
f) or ridges (1d, 1e) are formed, and the ground plate is provided with square holes (7c) or groove holes (7a, 7b) to be fitted with the above-mentioned projections and fitted to each other to form a board. It is characterized by holding the ground plate at a right angle. When the invention method of claim 10 described above is applied together with the invention method of claim 9, the "work for vertically fixing the substrate and the ground plate" in claim 9 can be performed reliably and accurately. . As a result, the manufacturing cost can be reduced, and the product having high quality and excellent reliability and durability can be configured.

In addition to the constituent features of the invention method of claims 9 and 10 (see FIG. 3), the structure of the invention method according to claim 11 is such that the substrate (1) faces the ground plate (7). At least one leg-like protrusion (1j, 1k) is formed in a shape extending the long side (1c), and the ground plate (7) has a "gate fitted to the leg-like protrusion (1j)". -Shaped engaging piece (7d) ", and" recessed with a spacing dimension (w) approximately equal to the thickness dimension (t) of the substrate,
Or, an engaging piece (7e) equivalent thereto is provided, and the leg-like projection (1j) at one end of the substrate is connected to the gate-shaped engaging piece (7d).
Insert (d) into the leg-shaped protrusion (1) at the other end of the substrate.
k) or the vicinity (1 m) of the other end is inserted into the interval (w) portion of the concave engaging piece and sandwiched to temporarily attach the substrate (1), and is further formed on the substrate. The conductive pattern and the gate-shaped engaging piece are soldered, and / or the conductive pattern and the concave-shaped engaging piece formed on the board are soldered to fix the board and the ground plate to each other. It is characterized by doing. According to the method of the eleventh aspect of the present invention described above, since both ends of the elongated substrate are fitted to the ground plate, both members can be positioned and fixed reliably. In addition, one end is an insertion type, and the other end is fitted by a sandwiching method, so workability is good. Moreover, since the fitted parts are soldered, the squareness of both members is firmly held,
An antenna with excellent reliability and durability is constructed.

[0015]

DETAILED DESCRIPTION OF THE INVENTION FIG. 1A is a perspective view showing an embodiment of the present invention. The substrate 1 is an elongated rectangular substrate, 1a is an upper long side, 1b is a short side, and 1c is a lower long side. In the present invention, the terms above and below are referred to by referring to the top and bottom of the drawings for convenience of description, and do not limit the configuration of the present invention. Substrate 1 for carrying out the present invention
As long as the shape is an elongated shape having a straight lower long side 1c, it is sufficient. In the present embodiment, the antenna element 2 that resonates at λ / 4 is configured by the L-shaped conductive pattern along the upper long side 1a and the short side 1b of the rectangle. The long side of the antenna element and the short side of the antenna element are indicated by reference numeral 2a.

An exciter 3 resonating at λ / 4 is arranged on the substrate 1 at the end opposite to the antenna short side 2b, and a small amount is provided between the output end and the antenna long side 2a. To form a large electrostatic capacitance c. The exciter 3 may be configured separately from the substrate 1, but in the present embodiment, it is configured in a zigzag shape by the conduction pattern. This exciter 3 does not necessarily have to have a zigzag conduction pattern,
A parallel conductive pattern having different inclination angles is formed on each of the front and back sides of the substrate, and the ends of the conductive patterns on the front and back sides are connected to each other by penetrating the substrate and using a well-known configuration of a square coil. Is also good. In any case,
It is convenient to construct the exciter with a conduction pattern because it is possible to construct a highly accurate exciter at low cost.

The reference numeral 7 indicates a slender ground plate. The lower long side 1c of the substrate is brought into vertical contact with the ground plate 7, and is positioned and temporarily attached as described later in detail with reference to FIGS.
As shown in FIG. 1, the antenna short side 2b and the ground plate 7
And are fixed by soldering 4 and are made conductive. FIG. 1B shows a perspective view of the vicinity of a short side parallel to the short side of the substrate indicated by reference numeral 1b as viewed in the direction of arrow b. Shown with reference numeral 8 in this figure is a small conductive pattern for mounting on a substrate, which is fixed to the ground plate 7 with solder 4. As a result, the small pattern 8 is kept at the ground potential. In the coaxial cable 10 shown in FIG. 1, the outer conductor 10a is soldered to the ground plate 7, and the core wire 10b is connected to the input end of the λ / 4 exciter. In this example, the portion where the core wire 10b is exposed from the outer conductor 10a acts as one portion of the exciter. Although not shown, a coaxial cable connector is connected to the other end (not shown) of the coaxial cable 10.

FIG. 2A is an exploded perspective view schematically showing a state in which the antenna of the embodiment shown in FIG. 1 is being constructed. On the lower long side 1c of the substrate 1, there are formed protrusions 1d and 1e that are long in the longitudinal direction of the substrate and protrusions 1f that are substantially square columnar. On the other hand, the ground plate 7 is provided with groove holes 7a and 7b which fit into the protrusions and square holes 7c which fit into the protrusions. The substrate 1 and the ground plate 7 are fixed to each other by the solder 4 as described above with reference to FIG. 1. However, as shown in FIG. 2, the convex portion of the substrate and the concave portion of the ground plate are separated from each other. When they are fitted together, the positioning and squareness can be easily maintained in the soldering work, and the joining strength after soldering is great. FIG. 2B shows an enlarged cross-sectional detail of the portion a surrounded by a chain line circle in FIG. The square hole 7c is not a punched hole that is simply punched,
Cut and raised pieces 1g and 1h are formed. With this configuration, the substrate 1 can be held at a right angle to the ground plate 7 (temporary fixing before soldering). In addition, depending on the relationship between the thickness of the substrate and the thickness of the ground plate, etc.
When it is difficult to form a pair of cut-and-raised pieces 1g and 1h as in (B), it is effective to provide one cut-and-raised piece (1g or 1h).

FIG. 3 is a partially cutaway exploded view showing an embodiment different from the above-described FIGS. 1 and 2 and enlarged for clarifying the portion different from the above-mentioned embodiment. The leg-shaped projections 1j and 1k are formed in such a manner that the lower long side 1c of the substrate 1 is extended in both directions. In the present invention, the term “leg-shaped” means having a ground contact surface (having a surface in contact with the ground plate 7). A gate-shaped engagement piece 7d is provided corresponding to one leg-shaped projection 1j and can be inserted (arrow d). And the other leg-shaped projection 1k
Is provided with a concave engaging piece 7e having a shape capable of being inserted and sandwiched as indicated by an arrow e. In the present embodiment, the gate-shaped engaging piece 7d and the concave engaging piece 7e are connected to the ground plate 7
It was cut and raised from. The concave engagement pieces in the present invention refer to a pair of pieces having a spacing dimension w that is substantially equal to the thickness dimension t of the substrate 1. As an embodiment different from the above, the holding portion 1m shown by the chain line may be held between the concave engagement pieces 7e. In this case, the leg-shaped projection 1k can be omitted. As described above, the leg-shaped projection 1j is inserted into the gate-shaped engaging piece 7d, and the board 1 is sandwiched by the concave-shaped engaging piece 7e. Soldering is performed, and the concave engagement piece 7e and the antenna element 2 are soldered.

FIG. 4 is a perspective view of an embodiment different from the above. Compared with FIG. 1 described above, the different points are extracted and listed as follows. The λ / 4 antenna element 2 is arranged along the board upper long side 1a and the board short side 1b,
Although it is formed in a substantially L shape, the portion along the short side 1b is set wider than the portion along the long side 1a, and the cutouts 2d, 2e, 2f are made to make a zigzag antenna short. The side 2c is configured. With this configuration, FIG.
The geometrical size of the λ / 4 antenna element 2 can be reduced as compared with the above embodiment, and therefore the overall antenna device can be made smaller and lighter.

FIG. 5 is a VSWR diagram of the low profile small antenna according to the embodiment shown in FIG. This example is 2
It is configured for 450MHz, but is 2310
It is shown to have a tuning frequency band of about 300 MHz between MHz and 2620 MHz.

[0022]

As described above, by clarifying the structure and operation of the embodiment of the present invention, when the invention of claim 1 is applied, the low-profile small-sized compact can be obtained by making the ground plate elongated. The thickness of the antenna is reduced to the same extent as the width of the ground plate. In addition, a high gain and a wide band property equivalent to those of the invention (Japanese Patent Application No. 2001-245430) according to an unknown invention can be obtained, and the manufacturing cost is low. When the invention of claim 2 is applied, since the exciter is configured by a conduction pattern, it is more suitable for industrial production than it is configured separately (for example, by using a wire), and the exciter can be excited with high accuracy and at low cost. Can be configured. Especially, the capacitance value can be regulated precisely,
The antenna performance can be made uniform. According to the invention of claim 3, when the antenna device part is manufactured and supplied by a specialized manufacturer, the antenna device is marketed as one assembly so that it is convenient for the radio device manufacturer to purchase and use it. In particular, the work of attaching the antenna device to the separately manufactured radio device can be performed quickly and easily.

According to the fourth aspect of the present invention, the convex portion formed on the substrate and the concave portion formed on the ground plate are fitted to each other so that the two members are firmly fixed to each other. It is easy to position the degree of parallelism of the member with high accuracy. According to the invention of claim 5, the contact area between the concave portion of the substrate and the concave portion of the ground plate is increased, so that the positioning action is ensured. According to the invention of claim 6, since both ends of the elongated board are fitted or sandwiched by the ground plate, both members can be positioned and fixed more reliably. According to the invention of claim 7, the fixing of the substrate and the ground plate is not only a simple fitting but also soldering, so that it is more reliable and strong. Moreover, by soldering the L-shaped antenna pattern and the ground plate,
Electrical connection continuity is ensured. According to the invention of claim 8, the short side of the substrate can be further shortened or the long side can be shortened, and the low-profile small antenna can be further downsized.

According to the ninth aspect of the invention, since the antenna element having a great influence on the characteristics of the antenna is constituted by the conductive pattern, a large number of products (antennas) of uniform quality suitable for industrial mass production can be obtained. In addition, it can be manufactured at low cost, and the antenna constructed by the method of the present invention has good performance and is small and lightweight. When the invention method of claim 10 is applied together with the invention method of claim 9, the "work for vertically fixing the substrate and the ground plate" in claim 9 can be performed reliably and accurately. As a result, the manufacturing cost can be reduced, and the product having high quality and excellent reliability and durability can be configured. According to the eleventh aspect of the present invention, since both ends of the elongated substrate are fitted to the ground plate, both members can be positioned and fixed reliably. In addition, one end is an insertion type, and the other end is fitted by a sandwiching method, so workability is good. Moreover, since the fitted parts are soldered, the squareness of both members is firmly held.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention viewed from two directions.

2A and 2B are an exploded perspective view and a partial cross-sectional view for explaining a state in the course of configuring the antenna of the embodiment shown in FIG. 1 above.

FIG. 3 is a perspective view schematically illustrating a state in the middle of configuring an antenna of an embodiment different from the above.

FIG. 4 is a perspective view depicting an improved example of the embodiment shown in FIG.

5 is a VSWR diagram of the antenna according to the embodiment shown in FIG. 1 above.

FIG. 6 Unknown prior application (Patent application 2001-24543)
It is a perspective view showing one embodiment of 0).

[Explanation of symbols]

1 ... Substrate, 1a ... Substrate upper long side, 1b ... Substrate short side, 1c
... Long sides of the lower side of the substrate, 1d, 1e ... Protrusions, 1f ... Protrusions, 1
g, 1h ... Cut-and-raised piece, 1i ... Short side of substrate, 1j, 1k ... Leg-like projection, 1m ... Holding part, 2 ... λ / 4 antenna element,
2a ... Antenna long side, 2b ... Antenna short side, 2c ... Zigzag antenna short side, 2d, 2e, 2f ... Notch, 3 ...
λ / 4 exciter, 4 ... Solder, 5 ... Substrate, 6 ... λ / 4 antenna pattern, 6a ... Zigzag portion, 7 ... Ground plate,
7a, 7b ... Groove hole, 7c ... Square hole, 7d ... Gate-shaped engaging piece, 7
e ... concave engaging piece, 8 ... small ground potential pattern (small ground plane pattern), 10 ... coaxial cable, 10a ... outer conductor,
10b ... Core wire, 11 ... Metal frame, 11a ... Flat plate portion (portion that functions as a ground plate), 11b ... Standing wall portion, 12 ... Exciter pattern, 13 ... Mounting screw.

Claims (11)

[Claims] 1. A λ / 4 antenna element resonating at λ / 4, comprising a substantially L-shaped conductive pattern formed along two adjacent sides of a rectangular or similar elongated substrate (1). 2), an exciter (3) resonating at λ / 4, which is installed near the end of the substrate opposite to the short side where the λ / 4 antenna element is formed, and a ground plate (7). The substrate, the long side of the side on which the antenna element is not formed is in contact with the surface of the ground plate, and the substrate and the ground plate are fixed so as to be perpendicular to each other, and The short-side end of the conduction pattern is connected to the ground plate for conduction, and the long-side tip of the conduction pattern is opposed to and separated from the output end of the exciter to form a capacitance (c). A low profile small antenna characterized by being 2. The exciter resonating at λ / 4 is constituted by a zigzag-shaped conduction pattern formed on the surface of the substrate, or both surfaces of the substrate have an inclination angle with respect to a long side. Front and back, different parallel conductive patterns are formed depending on the back, the end of the front side conductive pattern and the end of the back side conductive pattern are characterized in that they are connected to each other through the substrate, The low-profile small antenna according to claim 1. 3. The outer conductor (10a) of the coaxial cable is connected to the ground plate for conduction, and the core wire (10b) of the coaxial cable is connected to the exciter (3).
3. The low profile small antenna according to claim 1 or 2, wherein the input end of the coaxial cable is electrically connected and a coaxial cable connector is attached to the other end of the coaxial cable. 4. A wide portion protruding toward the ground plate (7) is provided at one or a plurality of portions of the long side (1c) of the substrate (1), and the ridges (1d, 1e) are provided. Or, the projection (1f) is formed, and on the other hand, the ground plate (7) is provided with the groove holes (7a, 7b) fitted to the projection or the square hole (7) fitted to the projection.
c) is punched, and the parallelism and squareness of the substrate and the ground plate are restricted by the fitting of the fitting portions, and the straightness is controlled. The described low profile small antenna. 5. A cut and raised piece (1g, 1h) obtained by cutting and raising a ground plate (7) is formed along an edge of the groove hole (7a, 7b) parallel to the long side of the substrate, The low-profile small-sized antenna according to claim 4, wherein the cut-and-raised piece serves as a positioning means for the substrate with respect to the ground plate. 6. A leg-shaped projection (1j) is formed on at least one of both ends of the long side of the elongated substrate which is in contact with the ground plate, and the ground plate has the above-mentioned structure. A gate-shaped engagement piece (7d) that engages with the leg-shaped projection, and a concave shape that closely fits the thickness dimension (t) of the substrate (1), or equivalent to a concave shape. An engaging piece (7e) is formed, which is characterized in that
The low-profile small-sized antenna according to claim 5. 7. A short side edge portion of a substantially L-shaped conductive pattern formed along two adjacent sides of the substrate is soldered (4) to a ground plate (7), And / or a small ground plane pattern (8) much smaller than the ground plate is formed near the end of the substrate on the side where the exciter (3) is provided, adjacent to the ground plate. The low profile small antenna according to any one of claims 1 to 6, characterized in that the small ground plane pattern is soldered (4) to the ground plane. 8. A substrate (1) having a shape similar to the rectangle 2
In the λ / 4 antenna element (2) formed of a substantially L-shaped conductive pattern formed along the side, the portion corresponding to the short side (1b) of the substrate is formed in a zigzag shape (2c). The low-profile small-sized antenna according to any one of claims 1 to 7, wherein 9. A method of constructing an antenna for transmitting and receiving radio waves of wavelength λ, wherein a long side and a short side of the rectangle are provided on a surface of a rectangular or elongated substrate (1) having a similar shape. Due to the almost L-shaped conduction pattern,
An antenna element (2) that resonates at / 4, and an exciter (3) that resonates at λ / 4 is arranged in the vicinity of a short side of the substrate that is not along the antenna element. A minute electrostatic capacitance c is formed between the output end of the substrate and the input end of the antenna element, and the long side of the substrate (1) is brought into contact with the ground plate (7) substantially vertically. A method of constructing a low-profile small antenna, characterized in that the antenna element (2) is fixed and the end of the portion along the short side of the substrate of the antenna element (2) is connected to the ground plate for electrical conduction. 10. The substrate (1) is a ground plate (7).
One or a plurality of protrusions (1f) or ridges (1d, 1e) are formed on the long side (1c) facing each other, and the ground plate has a square hole (7c) fitted with the above-mentioned protrusion. ) Or slot holes (7a, 7b) are provided and fitted to each other to hold the substrate and the ground plate at a right angle.
The method for configuring the low-profile small antenna according to claim 9. 11. The substrate (1) is a ground plate (7).
At least one leg-like protrusion (1j, 1k) is formed so as to extend the long side (1c) facing to, and the ground plate (7) is provided with the above-mentioned "leg-like protrusion (1j)". And a concave-shaped engaging piece (7e) having a clearance dimension (w) substantially equal to the thickness dimension (t) of the substrate. ) ”, And insert (d) the leg-like projection (1j) at one end of the board into the gate-shaped engaging piece (7d), and then the leg-like projection (1k) at the other end of the board, or the other The substrate (1) is temporarily attached by inserting the end portion (1 m) of the substrate into the space (w) of the concave engaging piece and sandwiching it, and further, the conductive pattern formed on the substrate and the gate shape. The engagement pattern is soldered, and / or the conduction pattern formed on the substrate and the concave engagement piece The soldered, characterized by fixing the substrate and the ground plate to each other, how to configure low-profile compact antenna according to claim 9 or claim 10.