JP2003032034A - Omnidirectional antenna - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To be compact and compact. SOLUTION: First and second printed dipole antennas 10, 10 in which a pair of parallel dipole antenna patterns 12 are formed on a dielectric substrate 11, and first and second printed dipole antennas 10, 1
And a printed power supply circuit 29 in which power supply circuit patterns 22 and 23 connected to each of the dipole antenna patterns 12 are formed on a dielectric substrate 21. The substrate 11 of each dipole antenna 10 is formed on these. The dipole antenna patterns 12 are arranged in parallel so that they face each other, and the substrate 20 of the printed power supply circuit is formed in an H-shaped cross section with the substrate 20 and the substrate 10 of the first and second printed dipole antennas. Are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed omnidirectional antenna.

[0002]

2. Description of the Related Art An omnidirectional antenna in which a vertical dipole antenna or the like is combined is used in a portable telephone simple base station or the like.

[0003]

Since the conventional omnidirectional antenna has a complicated structure, it is difficult to make it small and compact. Particularly, in the case of the array shape, the structure becomes more complicated, and the arrangement of the power supply line requires labor. The present invention has been made in view of such circumstances, and an object thereof is to provide an omnidirectional antenna that can be configured in a small size and a compact size.

[0004]

SUMMARY OF THE INVENTION The present invention is directed to first and second printed dipole antennas having a pair of parallel dipole antenna patterns formed on a dielectric substrate, and the first and second printed dipole antennas. And a printed feed circuit in which a feed circuit pattern connected to each dipole antenna pattern of the antenna is formed on a dielectric substrate, the substrate of the first printed dipole antenna and the printed dipole antenna of the second printed dipole antenna. A substrate, and the dipole antenna patterns formed on the substrates are arranged in parallel so as to face each other, and the substrate of the printed feeding circuit is provided on the substrate and the substrates of the first and second printed dipole antennas. And are arranged so as to form an H-shaped cross section.

According to the present invention, the substrate of the first printed dipole antenna, the substrate of the second printed dipole antenna, and the substrate of the printed feeding circuit are arranged so as to form an H-shaped cross section. , A small and compact omnidirectional antenna is constructed.

The dipole antenna patterns of the first and second printed dipole antennas are formed on the sides of the dipole antenna patterns in parallel and adjacent to each other, the dipole antenna patterns being shorter than the dipole antenna patterns. Each short dipole antenna pattern may be connected to the feeding circuit pattern. With this configuration, it is possible to share a plurality of frequencies.

The dipole antenna patterns of the first and second printed dipole antennas are formed on the sides of the dipole antenna patterns in parallel and adjacent to each other, the dipole antenna patterns being shorter than the dipole antenna patterns. Each short dipole antenna pattern may be separated from the feeding circuit pattern. According to this configuration, since each dipole antenna pattern having the short length resonates, the dipole antenna pattern can be shared by a plurality of frequencies.

A part of each of the dipole antenna patterns in the first and second printed dipole antennas is cut out, and a dipole antenna pattern having a shorter length than each of the dipole antenna patterns is provided in each of the dipole antenna patterns. The dipole antenna pattern having the short length may be connected to the feeding circuit pattern. According to this structure, the function shared by a plurality of frequencies can be realized with a more compact structure.

According to the present invention, first and second printed dipole array antennas are formed by cascading a plurality of pairs of parallel dipole antenna patterns in the longitudinal direction of a dielectric substrate, and the first and second printed dipole array antennas. A printed feed circuit in which a feed circuit pattern connected to each dipole antenna pattern of the printed dipole array antenna is formed on a dielectric substrate.
A printed circuit board of the dipole array antenna and a printed circuit board of the second printed dipole array antenna,
The plurality of pairs of dipole antenna patterns formed on them are arranged in parallel so as to face each other, and the substrate of the printed feed circuit is provided with the substrate and the substrates of the first and second printed dipole antennas. It is arranged so as to form an H-shaped cross section.

According to the present invention, the substrate of the first printed dipole array antenna, the substrate of the second printed dipole array antenna, and the substrate of the printed feeding circuit are arranged so as to form an H-shaped cross section. So
An omnidirectional antenna with a small and compact array configuration is constructed.

On the sides of the dipole antenna patterns in the first and second printed dipole array antennas, dipole antenna patterns having a shorter length than these dipole antenna patterns are formed in parallel and adjacent to each other. Each short dipole antenna pattern of this length can be configured to be connected to the feeding circuit pattern. With this configuration, it is possible to share a plurality of frequencies.

On the side of each dipole antenna pattern in the first and second printed dipole array antennas, a dipole antenna pattern having a shorter length than these dipole antenna patterns is formed in parallel and adjacently, Each short dipole antenna pattern of this length can be separated from the power feeding circuit pattern. According to this configuration, since each of the dipole antenna patterns having the short length described above resonates, the dipole antenna pattern can be shared by a plurality of frequencies.

A part of each dipole antenna pattern in the above-mentioned first and second printed dipole array antennas is cut out, and a dipole antenna pattern shorter than these dipole antenna patterns is provided in each of these dipole antenna patterns. Each of them may be formed, and each short dipole antenna pattern may be connected to the feeding circuit pattern. According to this configuration, the function shared by a plurality of frequencies can be realized more compactly.

A shield post pattern can be formed between each pair of dipole antenna patterns in the first and second printed dipole array antennas. According to this configuration, the interference between the pair of adjacent dipole antenna patterns is suppressed,
V. S. W. The R characteristic can be further improved.

The printed circuit of the printed circuit includes a ground pattern extending along the longitudinal direction of the substrate of the printed circuit, and a cover plate made of a conductor is disposed so as to face the ground pattern. The power supply cable may be arranged in a space formed between the plate and the ground pattern. With this configuration, it is possible to reduce the influence of the power feeding cable.

[0016]

1 is a sectional view showing an embodiment of an omnidirectional antenna according to the present invention. This antenna is used, for example, in a mobile phone simple base station or the like. In this omnidirectional antenna, a pair of printed dipole antennas 10 and 10 are arranged opposite to each other with a printed power feeding circuit 20 in between, and these are covered with a cover 3 made of FRP or the like.
It has a configuration of being housed in 0.

As shown in FIG. 2, the printed dipole antenna 10 includes a pair of dipole antenna patterns 12 and 12 on a rectangular dielectric substrate 11 and a pair of dipole antenna patterns 12 and 12 having a shorter length. The dipole antenna patterns 13 and 13 are formed of thin film conductors.

In this embodiment, the dipole antenna pattern 12 is applied to a frequency band of 810 to 960 MHz having a center frequency of 885 MHz, and the dipole antenna pattern 13 is 1.92 to 2 having a center frequency of 2.045 GHz. It is applied to the frequency band of 0.17 GHz.

Dipole antenna patterns 12, 12
Are formed along the longitudinal direction of the substrate 11 and parallel to each other, and in this example, their length L1 is about 0.4λ.
(885 MHz), and the distance L2 between them is set to about 0.15λ (885 MHz). The dipole antenna patterns 13 and 13 are
The dipole antenna patterns 12 and 12 are arranged on the outsides thereof so as to be parallel to each other, and in this example, their length L3 is set to about 0.37λ (2.045G), and their spacing L4 is set. About 0.52λ (2.
045 GHz).

The feeding points 12a, 12a on one side of the dipole antenna patterns 12, 12 and the feeding points 13a, 13a on one side of the dipole antenna patterns 13, 13 are feeding line patterns made of thin film conductors interposed between the feeding points 12a, 12a. 15a are commonly connected, and the other feeding point 12 of the dipole antenna patterns 12 and 12 is connected.
b, 12b and the other feeding points 13b, 13b of the dipole antenna patterns 13, 13 are feeding points 12b, 12b.
Feed line pattern 15 made of a thin film conductor interposed between
They are commonly connected by b.

On the other hand, in the printed power supply circuit 20, as shown in FIG. 3, the longitudinal length is set equal to that of the substrate 11 shown in FIG. 2, and the width L5 is about 0.16λ (88).
5 MHz), a rectangular dielectric substrate 21 set to 0.38λ (2.045 GHz) is provided, a branch circuit pattern 22 made of a thin film conductor is formed on one surface of the substrate 21, and the other surface is formed on the other surface. A ground pattern 23 made of a thin film conductor is formed.

The branch circuit pattern 22 has a main line 22a extending from one end of the substrate 21 to the central portion, and branch lines 22b and 22b branching left and right from the main line 22a. In addition, the ground pattern 23 is formed in such a manner that the central portion of the substrate 21 is cut in the longitudinal direction, and the width L6 thereof is
About 0.09λ (885MHz), 0.20λ (2.04)
5 GHz). The main line 22a is
In order to match with the branch lines 22b, 22b, the width is increased toward the tip.

As shown in FIG. 1, the substrates 11, 11 of the printed dipole antennas 10, 10 are arranged in parallel so that the surfaces on which the dipole antenna patterns 12, 13 are formed face each other. . Further, the board 21 of the printed power supply circuit 20 is interposed between the boards 11 and 11 such that one side and the other side are located on the central axes of the boards 11 and 11 in the longitudinal direction. Therefore,
The combined substrates 11 and 11 and the substrate 21 have an H-shaped cross-sectional shape.

Each branch line 22b, 22b of the branch circuit pattern 22 in the printed power feeding circuit 20 has a printed dipole antenna 10, the tip of which corresponds.
10 are electrically connected to the intermediate points of the power supply line patterns 15a by means of soldering or the like, and the ground pattern 23 in the printed power supply circuit 20 is a portion corresponding to the tips of the branch lines 22b, 22b. In, the printed dipole antennas 10 and 10 are electrically connected to the intermediate points of the feed line patterns 15b by the same means.

The omnidirectional antenna according to this embodiment having the above-mentioned structure has the above-mentioned substrates 11, 11 and 2 respectively.
1 is installed so as to face the vertical direction, and at that time, a power supply cable (not shown) is connected between the base end of the main line 22a and the corresponding end of the ground pattern 23 in the printed power supply circuit 20. It The power supply cable can be connected via a high frequency connector (not shown).

As shown in FIG. 1, in this omnidirectional antenna, four dipole antenna patterns 12 are located at respective corners of a substantially regular square, and four dipole antenna patterns 13 are more than the above regular square. One side is located at each corner of a slightly larger quadrangle.
Four vertically oriented dipole antenna patterns 1
Since the directivity 2 in the horizontal plane is a circle centered on the pattern 12, the directivity in the synthetic horizontal plane of these dipole antenna patterns 12 is substantially circular as described later.

Similarly, since the directivity in the horizontal plane of the four vertically oriented dipole antenna patterns 13 is a circle centered on the pattern 13, respectively, the directivity in the combined horizontal plane of these dipole antenna patterns 13 is also. It becomes almost circular. That is, the antenna structure composed of the four dipole antenna patterns 12 and the antenna structure composed of the four dipole antenna patterns 13 are:
Each has a function as an omnidirectional antenna.

FIG. 4 shows the V.V. of the omnidirectional antenna according to this embodiment. S. W. The R (voltage standing wave ratio) characteristic is shown. In addition, in FIG. 4, the scale on the horizontal axis is 200 MHz.
It is given in z steps, and the ordinate scale is given in 5 dB steps. As is apparent from FIG. 4, the omnidirectional antenna according to this embodiment has a good V.V. in the operating frequency band 810 to 960 MHz due to the action of the antenna structure including the four dipole antenna patterns 12. S, W. R characteristics, and an excellent V.V. S, W. The R characteristic is shown.

On the other hand, FIGS. 5, 6 and 7 show the frequency 810.0 MH of the omnidirectional antenna according to this embodiment.
z, 885.0 MHz and 960.0 MHz in-plane directional characteristics are also shown in FIGS. 8, 9 and 10.
Are the same antenna frequencies of 1.92 GHz and 2.04 GHz
The horizontal directional characteristics for z and 2.17 GHz are shown respectively. As you can see from these figures,
The omnidirectional antenna according to this embodiment has a good circular directional characteristic in a substantially circular shape in the used frequency band. In short, the antenna according to this embodiment has a good V.V. S, W. It operates as a dual-frequency omnidirectional antenna having an R characteristic and a horizontal directional characteristic.

Based on the configuration of the omnidirectional antenna,
It is also possible to construct an omnidirectional array antenna for dual frequency use. In this case, a pair of printed dipole array antennas 100 as shown in FIG. 11 and a printed feeding circuit 200 as shown in FIG. They are combined in the manner shown in FIG.

Printed dipole array antenna 10
0 is the printed dipole antenna 10 shown in FIG.
4 has been connected. That is, the printed dipole array antenna 100 includes the dipole antenna patterns 12, 12, the dipole antenna patterns 13, 13, and the feeding line patterns 15a, 1 described above.
Four sets of 5b are arrayed in the longitudinal direction of the long dielectric substrate 110. The shield post patterns 16 are formed of thin film conductors between the sets of patterns. In addition, the arrangement interval L7 of each pattern set
Are about 0.44λ (885 MHz) and 1.00λ (2.
045 GHz).

On the other hand, the printed power supply circuit 2 shown in FIG.
00 includes a dielectric substrate 210 having a length corresponding to the length of the substrate 110, a branch circuit pattern 220 made of a thin film conductor is formed on one surface of the substrate 210, and a thin film is formed on the other surface. A ground pattern 230 made of a conductor is formed.

The branch circuit pattern 220 constitutes a so-called parallel feeding circuit. That is, the pair of main lines 220 that branch from the central portion of the substrate 210 in the vertical direction of FIG.
a, branch lines 220b and 220b branching left and right from the ends of the main lines 220a, and branch lines 220c branching vertically from the ends of these lines 220b. The ground pattern 230 is located on the back surface of the power supply circuit pattern 220, and is formed in such a manner that the central portion of the substrate 210 is vertically cut along the longitudinal direction thereof.

Each of the above substrates 110, 110 and 210
Are arranged in the same manner as the substrates 11, 11 and 21 of the omnidirectional antenna described above, as shown in FIG. Each branch line 220c of the branch circuit pattern 220 in the printed power supply circuit 200 is soldered to the middle point of the corresponding power supply line pattern 150a of the printed dipole array antenna 100 to which the tip ends thereof correspond by means such as soldering. The ground pattern 230 in the printed power feeding circuit 200 is electrically connected, and the printed dipole array antenna 1 is provided at a portion corresponding to the tip of each branch line 220c.
No. 00 corresponding to the intermediate points of the power supply line pattern 15b are electrically connected by similar means. Furthermore,
The ground pattern 230 is electrically connected to the midpoint of each shield post 16 of each dipole array antenna 100 by means of soldering or the like.

In the omnidirectional array antenna according to this embodiment having such a configuration, the high frequency connector (not shown) is provided at the branch end of each main line 220a and the corresponding portion of the ground pattern 230 in the printed power feeding circuit 200. The power supply cable 170 is connected via.

As shown in FIG. 1, on the surface side of the feeding circuit board 210 on which the ground pattern 230 is formed,
The conductor plate 180 facing the pattern 230 is the substrate 2
The power supply cable 170 is arranged along the longitudinal direction of the conductor plate 180 and the ground pattern 2.
It is housed in the space formed between 30 and 30. A conductor plate 180 'is also provided on the opposite surface side of the power supply circuit board 210 for the purpose of electrical balance. Since the conductor plates 180 and 180 'are both grounded, the conductor plates 180 and 180' can also be utilized as a ground line when a lightning rod (not shown) is provided.

This omnidirectional array antenna has a structure in which the above-mentioned omnidirectional antenna is used as an element antenna and four element antennas are linearly arranged. That is, it is an array antenna having a 4-element 1-block configuration. V. of individual element antennas S, W. The R characteristic is as shown in FIG. Therefore, this omnidirectional array antenna is also shown in FIG.
As shown in FIG. 5, good V.2 in the used frequency bands 810 to 960 MHz and 1.92 to 2.17 GHz. S,
W. The R characteristic is shown.

This omnidirectional array antenna can be constructed very easily by simply combining each printed dipole array antenna 100 and the printed feeding circuit 200 in a H-shaped cross section. In addition, one power supply cable 1
70 can be used for power feeding, and the power feeding cable 170 is connected to the ground conductor plate 180 and the ground pattern 2.
Since it can be accommodated in the space formed between the power supply cable 30 and 30, it is possible to obtain good directional characteristics that are not affected by this power supply cable. It should be noted that the shield post pattern 16 is formed by the adjacent dipole antenna pattern 1.
2 and 12 are shielded from each other, and V. S. W. It acts to improve the R characteristics.

By arranging a plurality of 4-element 1-block omnidirectional array antennas in the vertical direction, a large omnidirectional array antenna having a larger number of element antennas can be constructed. That is, for example, as shown in FIG. 14, a 16-element omnidirectional array antenna can be configured by connecting the 4-element 1-block omnidirectional array antenna in four blocks (1B to 4B) in multiple stages.

In this case, each feeding cable 170 connected to the omnidirectional array antenna of each block 1B to 4B.
0.8 GH via 4 power distributor 30 and duplexer 31
It is connected to the z-band connection terminal 32 and the 2 GHz band connection terminal 33. Of course, since these power supply cables 170 are housed between the ground pattern 230 and the conductor plate 180 shown in FIG. 1, there is no possibility that these power supply cables 170 and their connectors will adversely affect the directivity and the like. When these four power supply cables 180 and the connectors for connecting them are arranged in a random manner, the directional characteristics and the like are deteriorated. In addition, the above four power supply cables 1
It is also possible to insert a phase shifter in the middle of 70 to change the tilt angle of the beam in each element antenna.

By the way, the dipole antenna patterns 13 and 13 shown in FIGS.
a and 13b are power supply line patterns 15a and 15 respectively.
corresponding dipole antenna pattern 12 via b,
12 are connected to the feeding points 12a and 12b.
As shown in FIG. 5, the dipole antenna patterns 13, 1
It is also possible to separate 3 from the corresponding dipole antenna patterns 12 and 12. In this case, the dipole antenna patterns 13 and 13 are arranged in the same manner as in FIG.
Although it is separated from the printed feed circuits 20 and 200 shown in FIG. 2, it will operate as a dipole antenna in the applicable frequency band due to resonance.

The dipole antenna patterns 13 and 13 shown in FIGS. 2 and 11 are formed near the outer sides of the corresponding dipole antenna patterns 12 and 12, respectively, but as shown in FIG. It is also possible to form the pole antenna patterns 13 and 13 inside the pole antenna patterns 12 and 12 by providing a pair of substantially U-shaped cutout portions 12c that face each other.

In the above description, the omnidirectional antenna shared with two frequencies has been described, but an omnidirectional antenna shared with waves of three or more frequencies can also be configured. That is,
For example, in the case of constructing an omnidirectional antenna shared by three frequencies, the dipole antenna pattern 1 shown in FIG.
The dipole antenna pattern 13,
Different dipole antenna patterns having different lengths from 13 and the dipole antenna patterns 12 and 12 may be formed. Further, in the example of FIG. 16, the dipole antenna patterns 13 and 13 are provided with a cutout portion similar to the above-described substantially U-shaped cutout portion 12c, and another dipole antenna pattern is provided in the pole antenna patterns 13 and 13. Should be formed.

[0044]

According to the present invention, a small and compact omnidirectional antenna and an omnidirectional antenna having an array configuration can be constructed. Further, an omnidirectional antenna that can be shared by a plurality of frequencies and an omnidirectional antenna having an array configuration can be easily configured without impairing compactness. Further, in the omnidirectional antenna having the array configuration, by arranging the power feeding cable between the ground pattern of the printed power feeding circuit and the cover plate facing this, it is possible to suppress the influence of the power feeding cable and to improve the performance. It is possible to obtain various directional characteristics.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an omnidirectional antenna according to the present invention.

FIG. 2 is a plan view showing a configuration example of a printed dipole antenna.

FIG. 3 is a plan view showing a configuration example of a printed power supply circuit.

FIG. 4 is a diagram showing the V.V. of the omnidirectional antenna according to the present invention. S. W. R
It is a graph which illustrated the characteristic.

FIG. 5 shows a frequency of an omnidirectional antenna according to the present invention 810.
It is a graph which illustrated the directivity in a horizontal plane about 0 MHz.

FIG. 6 shows a frequency of an omnidirectional antenna according to the present invention 885.
It is a graph which illustrated the directivity in a horizontal plane about 0 MHz.

FIG. 7 shows a frequency of the omnidirectional antenna 960.
It is a graph which illustrated the directivity in a horizontal plane about 0 MHz.

FIG. 8 shows a frequency of an omnidirectional antenna according to the present invention of 1.92.
It is a graph which illustrated the directivity in a horizontal plane about GHz.

FIG. 9 shows a frequency of 2.04 of the omnidirectional antenna according to the present invention.
It is a graph which illustrated the directivity in a horizontal plane about 5 GHz.

FIG. 10 shows a frequency 2.1 of the omnidirectional antenna according to the present invention.
It is a graph which illustrated the directivity in a horizontal plane about 7 GHz.

FIG. 11 is a plan view showing a configuration example of a printed dipole array antenna.

FIG. 12 is a plan view showing a configuration example of a printed power supply circuit for a printed dipole array antenna.

FIG. 13 is a diagram showing the V.V. of the omnidirectional array antenna according to the present invention.
S. W. It is a graph which illustrated R characteristic.

FIG. 14 is a block diagram showing an example of an electrical connection form of a 16-element omnidirectional array antenna according to the present invention.

FIG. 15 is a plan view showing another configuration example of the dipole antenna pattern.

FIG. 16 is a plan view showing still another configuration example of the dipole antenna pattern.

[Explanation of symbols]

10,100 printed dipole antenna 11,110,21,210 Dielectric substrate 12,13 dipole antenna pattern 12a, 12b, 13a, 13b Feeding point 12c Notch 15a, 15b Feeding line pattern 23,230 ground pattern 170 power supply cable 180 conductor plate

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shunichi Nishizawa             3-3-1 Marunouchi, Chiyoda-ku, Tokyo             Ki Kogyo Co., Ltd. (72) Inventor Masayoshi Shintaku             2-11-1, Nagatacho, Chiyoda-ku, Tokyo Stock             Ceremony company NTT Docomo F-term (reference) 5J021 AA07 AB03 FA32 GA07 HA05                       HA10 JA07                 5J046 AA04 AA07 AB07 PA07 RA03

Claims (10)

[Claims] 1. A first and a second printed dipole antenna in which a pair of parallel dipole antenna patterns are formed on a dielectric substrate, and the dipole antenna patterns of the first and the second printed dipole antennas, respectively. A printed feed circuit in which a feed circuit pattern to be connected is formed on a dielectric substrate, and a substrate for the first printed dipole antenna and a substrate for the second printed dipole antenna are formed on them. Further, the dipole antenna patterns are arranged in parallel so as to face each other, and the substrate of the printed feed circuit forms an H-shaped cross section between the substrate and the substrates of the first and second printed dipole antennas. An omnidirectional antenna characterized by being arranged so that 2. A dipole antenna pattern having a length shorter than these dipole antenna patterns is formed parallel to and adjacent to each of the dipole antenna patterns in the first and second printed dipole antennas. 2. The short dipole antenna pattern is connected to the feeding circuit pattern.
The omnidirectional antenna described in. 3. A dipole antenna pattern having a length shorter than these dipole antenna patterns is formed in parallel and adjacent to each side of the dipole antenna patterns in the first and second printed dipole antennas. The omnidirectional antenna according to claim 1, wherein the short dipole antenna patterns are separated from the feeding circuit pattern. 4. A dipole antenna pattern having a shorter length than each of these dipole antenna patterns by cutting out a part of each dipole antenna pattern in the first and second printed dipole antennas. 2. Each of the short dipole antenna patterns is connected to the feeding circuit pattern.
The omnidirectional antenna described in. 5. A first and a second printed dipole array antenna formed by cascading a plurality of pairs of parallel dipole antenna patterns in a longitudinal direction of a dielectric substrate, and the first and second printed circuits. A printed feed circuit in which a feed circuit pattern connected to each dipole antenna pattern of the simplified dipole array antenna is formed on a dielectric substrate, the first printed dipole array antenna substrate and the second print And a substrate of the printed dipole array antenna are arranged in parallel so that the plurality of pairs of dipole antenna patterns formed thereon face each other, and the substrate of the printed power feeding circuit is arranged on the substrate and the first and second substrates. The printed dipole antenna substrate and the substrate are arranged so as to form an H-shaped cross section. Omnidirectional antenna, characterized in that the. 6. A dipole antenna pattern having a length shorter than these dipole antenna patterns is formed parallel to and adjacent to each of the dipole antenna patterns in the first and second printed dipole array antennas. 7. The short dipole antenna pattern is connected to the feeding circuit pattern.
The omnidirectional antenna described in. 7. A dipole antenna pattern having a shorter length than these dipole antenna patterns is formed in parallel and adjacent to each side of the dipole antenna patterns in the first and second printed dipole array antennas. The omnidirectional antenna according to claim 5, wherein each of the short dipole antenna patterns is separated from the feeding circuit pattern. 8. A dipole antenna having a length shorter than these dipole antenna patterns in each of these dipole antenna patterns by cutting out a part of each dipole antenna pattern in the first and second printed dipole array antennas. A pattern is formed respectively, and each dipole antenna pattern having the short length is connected to the feeding circuit pattern.
The omnidirectional antenna described in. 9. A shield post pattern is formed between each pair of dipole antenna patterns in the first and second printed dipole array antennas, respectively. Omnidirectional antenna. 10. A power supply circuit pattern of the printed power supply circuit includes a ground pattern extending in a longitudinal direction of a substrate of the power supply circuit, and a cover plate made of a conductor is arranged to face the ground pattern. The omnidirectional antenna according to any one of claims 5 to 9, wherein a feed cable is arranged in a space formed between the cover plate and the ground pattern.