JP3553032B2 - Omnidirectional antenna - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a printed omnidirectional antenna.
[0002]
[Prior art]
In a simple base station for a mobile phone or the like, an omnidirectional antenna combined with a vertical dipole antenna or the like is used.
[0003]
[Problems to be solved by the invention]
The conventional omnidirectional antenna has a complicated structure, so that it is difficult to make it compact and compact. In particular, in the case of an array configuration, the structure is further complicated, and the arrangement of the power supply line requires time and effort.
The present invention has been made in view of such a situation, and an object of the present invention is to provide an omnidirectional antenna that can be configured to be small and compact.
[0004]
[Means for Solving the Problems]
The present invention relates to first and second printed dipole antennas in which a pair of parallel dipole antenna patterns are formed on a rectangular dielectric substrate, and dipole antenna patterns of the first and second printed dipole antennas. And a printed feed circuit in which a parallel feed circuit pattern formed on the dielectric substrate is connected to each of the first and second printed dipole antennas. along the longitudinal axis of the substrate, and is formed so as to be located symmetrically about the said axis, the first, the dielectric substrate of the second print of dipole antennas, each being formed on their with the dipole antenna pattern mutually parallel arranged to face the first One side and the other side of the dielectric substrate of the printed power supply circuit so that the dielectric substrate of the second printed dipole antenna and the dielectric substrate of the printed power supply circuit form an H-shaped cross section. The opposed first and second printed dipole antennas are located on the longitudinal axis of the dielectric substrate .
[0005]
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 power supply circuit are arranged so as to form an H-shaped cross section, so that they are small and compact. A compact omnidirectional antenna is configured.
[0006]
Dipole antenna patterns shorter in length than these dipole antenna patterns are formed in parallel and adjacent to the sides of each dipole antenna pattern in the first and second printed dipole antennas, respectively. Each short dipole antenna pattern can be configured to be connected to the power supply circuit pattern. According to this configuration, it is possible to share a plurality of frequencies.
[0007]
Dipole antenna patterns shorter in length than these dipole antenna patterns are formed in parallel and adjacent to the sides of each dipole antenna pattern in the first and second printed dipole antennas, respectively. Each short dipole antenna pattern may be configured to be separated from the power supply circuit pattern. According to this configuration, each of the short dipole antenna patterns performs a resonance operation, so that it is possible to share the dipole antenna patterns for a plurality of frequencies.
[0008]
A part of each dipole antenna pattern in the first and second printed dipole antennas is cut out, and a dipole antenna pattern shorter in length than these dipole antenna patterns is formed in each of these dipole antenna patterns. Each of the short dipole antenna patterns may be connected to the power supply circuit pattern. According to this configuration, a function shared by a plurality of frequencies can be realized with a more compact configuration.
[0009]
The present invention provides 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 rectangular dielectric substrate, and the first and second printed dipole array antennas. A printed feed circuit formed on a dielectric substrate with a parallel feed circuit pattern connected to each dipole antenna pattern of the printed dipole array antenna, and a pair of dipoles in the first and second printed dipole antennas. antenna pattern, along the longitudinal axis of the dielectric substrate of those antennas, and is formed so as to be located symmetrically about the axial line, the dielectric of the first, second printing of dipole array antenna the body substrate, wherein each dipole antenna pattern mutually formed thereof With parallel arranged to counter, the first, as a dielectric substrate of a dielectric substrate and the printed of the feed circuit of the second print of dipole array antenna to form a H-shaped cross section, said print of One side and the other side of the dielectric substrate of the feeding circuit are respectively located on the longitudinal axis of the dielectric substrate of the first and second printed dipole array antennas facing each other.
[0010]
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 power supply circuit are arranged so as to form an H-shaped cross section. An omnidirectional antenna having a small and compact array configuration is configured.
[0011]
Dipole antenna patterns shorter in length than these dipole antenna patterns are formed in parallel and adjacent to the sides of each dipole antenna pattern in the first and second printed dipole array antennas, respectively. The short dipole antenna patterns can be connected to the power supply circuit pattern. According to this configuration, it is possible to share a plurality of frequencies.
[0012]
Dipole antenna patterns shorter in length than these dipole antenna patterns are formed in parallel and adjacent to the sides of each dipole antenna pattern in the first and second printed dipole array antennas, respectively. The short dipole antenna patterns can be separated from the power supply circuit pattern. According to this configuration, each of the short dipole antenna patterns performs a resonance operation, so that it is possible to share the dipole antenna patterns for a plurality of frequencies.
[0013]
A part of each dipole antenna pattern in the first and second printed dipole array antennas is cut out, and a dipole antenna pattern having a shorter length than these dipole antenna patterns is formed in each dipole antenna pattern. Each of the short dipole antenna patterns may be connected to the power supply circuit pattern. According to this configuration, a function shared by a plurality of frequencies can be realized more compactly.
[0014]
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, interference between pairs of adjacent dipole antenna patterns is suppressed, and S. W. The R characteristic can be further improved.
[0015]
The power supply circuit pattern of the printed power supply circuit includes a ground pattern along a longitudinal direction of a substrate of the power supply circuit, and a cover plate made of a conductive material is disposed to face the ground pattern. The power supply cable can be arranged in a space formed between the ground patterns. According to this configuration, the influence of the power supply cable can be reduced.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a sectional view showing an embodiment of the omnidirectional antenna according to the present invention. This antenna is used, for example, in a simple base station for mobile phones.
This omnidirectional antenna has a configuration in which a pair of printed dipole antennas 10 and 10 are disposed to face each other via a printed power supply circuit 20, and are housed in a cover 30 made of FRP or the like.
[0017]
As shown in FIG. 2, the printed dipole antenna 10 has a pair of dipole antenna patterns 12 and 12 on a rectangular dielectric substrate 11 and a pair of dipole antennas shorter in length than the dipole antenna patterns 12 and 12. Each of the patterns 13, 13 is formed of a thin film conductor.
[0018]
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 applied to a frequency band of 1.92 to 2.17 GHz having a center frequency of 2.045 GHz. Applies to frequency bands.
[0019]
The dipole antenna patterns 12 and 12 are formed along the longitudinal direction of the substrate 11 and parallel to each other. In this example, the length L1 is set to about 0.4λ (885 MHz) and the distance between them is set. L2 is set to about 0.15λ (885 MHz).
The dipole antenna patterns 13 and 13 are disposed outside the dipole antenna patterns 12 and 12 in parallel with the dipole antenna patterns 12 and 12, respectively. In this example, the length L3 of the dipole antenna patterns 13 and 13 is about 0.37λ (2.045G). At the same time, the interval L4 is set to about 0.52λ (2.045 GHz).
[0020]
One of the feeding points 12a, 12a of the dipole antenna patterns 12, 12 and one of the feeding points 13a, 13a of the dipole antenna patterns 13, 13 are shared by a feeding line pattern 15a made of a thin film conductor interposed between the feeding points 12a, 12a. The other feed points 12b, 12b of the dipole antenna patterns 12, 12 and the other feed points 13b, 13b of the dipole antenna patterns 13, 13 are connected to each other by a thin film conductor interposed between the feed points 12b, 12b. They are commonly connected by a line pattern 15b.
[0021]
On the other hand, as shown in FIG. 3, the printed power supply circuit 20 has a longitudinal length equal to that of the substrate 11 shown in FIG. 2, and a width L5 of about 0.16λ (885 MHz), 0.38λ ( 2.045 GHz), a branch circuit pattern 22 made of a thin film conductor is formed on one surface of the substrate 21 and a ground pattern 23 made of a thin film conductor is formed on the other surface. Is formed.
[0022]
The branch circuit pattern 22 has a main line 22a extending from one end of the substrate 21 to a central portion, and branch lines 22b, 22b branching left and right from the main line 22a. The ground pattern 23 is formed so as to extend longitudinally through the center of the substrate 21 in the longitudinal direction, and has a width L6 set to about 0.09λ (885 MHz) and 0.20λ (2.045 GHz).
The main line 22a is formed such that its width becomes wider toward the distal end in order to match with the branch lines 22b.
[0023]
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 substrate 21 of the printed power supply circuit 20 is interposed between the substrates 11, 11 such that one side and the other side are located on the respective central axes in the longitudinal direction of the substrates 11, 11. Therefore, the combined substrates 11 and 11 have an H-shaped cross-sectional shape.
[0024]
Each of the branch lines 22b, 22b of the branch circuit pattern 22 in the printed power supply circuit 20 is electrically connected to the intermediate point of the corresponding power supply line pattern 15a of the printed dipole antenna 10, 10 by soldering or the like. And the ground pattern 23 in the printed power supply circuit 20 is located at an intermediate point of the power supply line pattern 15b of the printed dipole antennas 10 at a portion corresponding to the tip of each of the branch lines 22b. They are electrically connected by similar means.
[0025]
The omnidirectional antenna according to this embodiment having such a configuration is installed such that the substrates 11, 11 and 21 are oriented in a vertical direction. At this time, the base line 22a in the printed power supply circuit 20 is mounted. A power supply cable (not shown) is connected between the end and the corresponding end of the ground pattern 23. The power supply cable can be connected via a high-frequency connector (not shown).
[0026]
As shown in FIG. 1, in this omnidirectional antenna, four dipole antenna patterns 12 are respectively located at the respective corners of a substantially square, and four dipole antenna patterns 13 are slightly smaller on one side than the above-described substantially square. It is located at each corner of the large square.
Since the directivity in the horizontal plane of each of the four vertically oriented dipole antenna patterns 12 is circular with the pattern 12 as the center, the directivity in the composite horizontal plane of these dipole antenna patterns 12 is substantially circular as described later. become.
[0027]
Similarly, the directivity in the horizontal plane of each of the four vertically oriented dipole antenna patterns 13 is a circle centered on the respective pattern 13, so that the directivity in the composite horizontal plane of these dipole antenna patterns 13 is also substantially circular. Become.
That is, the antenna structure including the four dipole antenna patterns 12 and the antenna structure including the four dipole antenna patterns 13 each have a function as an omnidirectional antenna.
[0028]
FIG. 4 is a block diagram of the omnidirectional antenna according to this embodiment. S. W. It shows an R (voltage standing wave ratio) characteristic. In FIG. 4, the scale on the horizontal axis is given in 200 MHz steps, and the scale on the vertical axis is given in 5 dB steps.
As is apparent from FIG. 4, the omnidirectional antenna according to this embodiment has a good V.I.D. in the used frequency band of 810 to 960 MHz due to the operation of the antenna structure composed of four dipole antenna patterns 12. S, W. R characteristic, and a good V.I. in the operating frequency band of 1.92 to 2.17 GHz due to the effect of the antenna structure composed of the four dipole antenna patterns 13. S, W. The R characteristic is shown.
[0029]
On the other hand, FIG. 5, FIG. 6 and FIG. 7 show the directional characteristics in the horizontal plane of the omnidirectional antenna according to this embodiment at frequencies of 810.0 MHz, 885.0 MHz and 960.0 MHz, and FIG. FIG. 10 shows the directional characteristics in the horizontal plane for the frequencies 1.92 GHz, 2.04 GHz, and 2.17 GHz of the antenna, respectively.
As is apparent from these figures, the omnidirectional antenna according to this embodiment has a good circular in-plane directional characteristic in a used frequency band.
In short, the antenna according to this embodiment has a good V.I. S, W. It acts as a dual frequency omnidirectional antenna having an R characteristic and a directional characteristic in a horizontal plane.
[0030]
Based on the configuration of the omnidirectional antenna, it is also possible to configure a dual-frequency omnidirectional array antenna. In this case, a pair of a printed dipole array antenna 100 as shown in FIG. The printed power supply circuit 200 as shown is combined in the manner shown in FIG.
[0031]
The printed dipole array antenna 100 has a configuration in which four printed dipole antennas 10 shown in FIG. 2 are connected. That is, the printed dipole array antenna 100 includes four sets of dipole antenna patterns 12 and 12, dipole antenna patterns 13 and 13, and feed line patterns 15 a and 15 b in the longitudinal direction of the long dielectric substrate 110. An array is formed.
In addition, between each pair of patterns, the shield post pattern 16 is formed by a thin film conductor. The arrangement interval L7 of each pattern set is set to about 0.44λ (885 MHz) and 1.00λ (2.045 GHz).
[0032]
On the other hand, the printed power supply circuit 200 shown in FIG. 12 includes a dielectric substrate 210 having a length corresponding to the length of the substrate 110, and a branch circuit pattern 220 made of a thin film conductor is formed on one surface of the substrate 210. And a ground pattern 230 made of a thin film conductor is formed on the other surface.
[0033]
The branch circuit pattern 220 forms a so-called parallel power supply circuit. That is, a pair of main lines 220a that branch in the vertical direction in FIG. 12 from the center of the substrate 210, branch lines 220b and 220b that branch left and right from the end of each main line 220a, And a branch line 220c that branches in the direction. The ground pattern 230 is located on the back surface of the power supply circuit pattern 220 and is formed in a manner to vertically cross a central portion of the substrate 210 along its longitudinal direction.
[0034]
As shown in FIG. 1, the boards 110, 110 and 210 are arranged in the same manner as the boards 11, 11 and 21 of the omnidirectional antenna described above. Then, each of the branch lines 220c of the branch circuit pattern 220 in the printed power supply circuit 200 is soldered to an intermediate point of the corresponding power supply line pattern 150a of the printed dipole array antenna 100 corresponding to the leading end thereof by means such as soldering. The ground pattern 230 in the printed power supply circuit 200 is electrically connected to the middle point of the corresponding power supply line pattern 15b of the printed dipole array antenna 100 at a position corresponding to the tip of each branch line 220c. They are electrically connected by similar means.
Further, the ground pattern 230 is electrically connected to the midpoint of each shield post 16 of each dipole array antenna 100 by means such as soldering.
[0035]
In the omni-directional array antenna according to this embodiment having such a configuration, the branch end of each main line 220a in the printed power supply circuit 200 and a portion corresponding to the ground pattern 230 are connected via a high-frequency connector (not shown). The power supply cable 170 is connected.
[0036]
As shown in FIG. 1, a conductor plate 180 facing the pattern 230 is provided along the longitudinal direction of the substrate 210 on the surface of the power supply circuit board 210 on which the ground pattern 230 is formed. The power supply cable 170 is housed in a space formed between the conductor plate 180 and the ground pattern 230.
A conductor plate 180 ′ is also provided on the opposite side of the power supply circuit board 210 for the purpose of achieving an electrical balance. Since the conductor plates 180 and 180 'are both grounded, they can also be used as ground lines when a lightning rod (not shown) is provided.
[0037]
This omnidirectional array antenna has a configuration in which the omnidirectional antenna described above is used as an element antenna, and four such element antennas are linearly arranged. That is, the array antenna has a four-element one-block configuration. V. of individual element antennas S, W. The R characteristic is as shown in FIG. Therefore, as shown in FIG. 13, this omnidirectional array antenna also has a good V.V. frequency band in the used frequency band of 810 to 960 MHz and 1.92 to 2.17 GHz. S, W. The R characteristic is shown.
[0038]
This omnidirectional array antenna can be configured very easily only by combining each of the printed dipole array antennas 100 and the printed power supply circuit 200 in an H-shaped cross section. Further, power can be supplied using one power supply cable 170, and the power supply cable 170 can be housed in the space formed between the ground conductor plate 180 and the ground pattern 230. Good directional characteristics not affected by the power supply cable can be obtained.
The shield post pattern 16 shields the adjacent dipole antenna patterns 12 from each other, and S. W. It functions to improve the R characteristic.
[0039]
By arranging the four-element one-block omnidirectional array antenna in a plurality of stages in the vertical direction, a large omnidirectional array antenna having a larger number of element antennas can be configured. That is, for example, as shown in FIG. 14, if the four-element one-block omnidirectional array antenna is connected in multiple stages of four blocks (1B to 4B), a sixteen-element omnidirectional array antenna can be configured.
[0040]
In this case, the power supply cables 170 connected to the omnidirectional array antennas of the individual blocks 1B to 4B are connected to the 0.8 GHz band connection terminal 32 and the 2 GHz band connection terminal 33 via the four power distributor 30 and the duplexer 31. Connected to. Of course, since these power supply cables 170 are accommodated 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 directivity and the like. If the four power supply cables 180 and the connector for connecting the four power supply cables 180 are arranged at random, deterioration in directional characteristics and the like will be caused.
In addition, it is also possible to insert a phase shifter in the middle of the four feed cables 170 to change the tilt angle of the beam in each element antenna.
[0041]
By the way, the dipole antenna patterns 13 and 13 shown in FIGS. 2 and 11 have feed points 13a and 13b connected to feed points 12a and 12b of the corresponding dipole antenna patterns 12 and 12 via feed line patterns 15a and 15b, respectively. Although connected, as shown in FIG. 15, it is also possible to form the dipole antenna patterns 13, 13 separated from the corresponding dipole antenna patterns 12, 12.
In this case, the dipole antenna patterns 13 and 13 are separated from the printed power supply circuits 20 and 200 shown in FIGS. 3 and 12, but operate as a dipole antenna in the applicable frequency band due to resonance.
[0042]
The dipole antenna patterns 13 and 13 shown in FIGS. 2 and 11 are formed near the outside of the corresponding dipole antenna patterns 12 and 12, respectively, as shown in FIG. By providing a pair of substantially U-shaped notches 12c opposed to each other, it is possible to form the pole antenna patterns 13, 13 inside the pole antenna patterns 12, 12.
[0043]
In the above, the omnidirectional antenna shared by two frequencies has been described, but an omnidirectional antenna shared by three or more frequencies can also be configured. That is, for example, when an omnidirectional antenna shared by three frequencies is configured, the dipole antenna patterns 13 and 13 and the dipole antenna patterns 12 and 12 are long near the dipole antenna patterns 13 and 13 shown in FIG. Different dipole antenna patterns having different sizes may be formed.
In the example of FIG. 16, a notch similar to the above-described substantially U-shaped notch 12c is provided in the dipole antenna patterns 13 and 13, and another dipole antenna pattern is provided in the pole antenna patterns 13 and 13. May be formed.
[0044]
【The invention's effect】
According to the present invention, a small and compact omnidirectional antenna and an omnidirectional antenna having an array configuration can be configured.
In addition, the omnidirectional antenna and the omnidirectional antenna having an array configuration that can be shared by a plurality of frequencies can be easily configured without impairing compactness.
In an omnidirectional antenna having an array configuration, a power supply cable is provided between a ground pattern of a printed power supply circuit and a cover plate facing the power supply circuit, so that the influence of the power supply cable is suppressed, and the antenna is further improved. Directional characteristics can be obtained.
[Brief description of the 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 illustrating a configuration example of a printed dipole antenna.
FIG. 3 is a plan view illustrating a configuration example of a printed power supply circuit.
FIG. 4 shows the V.I. of the omnidirectional antenna according to the present invention. S. W. It is a graph which illustrated R characteristic.
FIG. 5 is a graph illustrating a directional characteristic in a horizontal plane for a frequency of 810.0 MHz of the omnidirectional antenna according to the present invention.
FIG. 6 is a graph illustrating the directional characteristics in the horizontal plane of the omnidirectional antenna according to the present invention at a frequency of 885.0 MHz.
FIG. 7 is a graph illustrating directional characteristics in a horizontal plane of the omnidirectional antenna according to the present invention at a frequency of 960.0 MHz.
FIG. 8 is a graph illustrating a directional characteristic in a horizontal plane at a frequency of 1.92 GHz of the omnidirectional antenna according to the present invention.
FIG. 9 is a graph illustrating the directional characteristics in a horizontal plane of the omnidirectional antenna according to the present invention at a frequency of 2.045 GHz.
FIG. 10 is a graph illustrating a directional characteristic in a horizontal plane at a frequency of 2.17 GHz of the omnidirectional antenna according to the present invention.
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 shows the V.I. S. W. It is a graph which illustrated R characteristic.
FIG. 14 is a block diagram showing an example of an electrical connection configuration 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, 21 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 Feeding cable 180 conductor plate

Claims (10)

A first and a second printed dipole antenna in which a pair of parallel dipole antenna patterns are formed on a rectangular dielectric substrate;
A printed power supply circuit in which a parallel power supply circuit pattern connected to each of the dipole antenna patterns of the first and second printed dipole antennas is formed on a dielectric substrate,
The pair of dipole antenna patterns in the first and second printed dipole antennas are formed so as to be along the longitudinal axis of the dielectric substrate of those antennas and to be symmetrical about the axis. ,
The dielectric substrates of the first and second printed dipole antennas are arranged in parallel so that the respective dipole antenna patterns formed thereon face each other , and the dielectric substrates of the first and second printed dipole antennas are arranged . First and second facing sides of one side and the other side of the dielectric substrate of the printed power supply circuit so that the dielectric substrate and the dielectric substrate of the printed power supply circuit form an H-shaped cross section. An omnidirectional antenna, wherein the antenna is located on a longitudinal axis of a dielectric substrate of the printed dipole antenna. Forming a dipole antenna pattern shorter in length than these dipole antenna patterns in parallel and adjacent to each of the dipole antenna patterns in the first and second printed dipole antennas,
The omnidirectional antenna according to claim 1, wherein each of the short dipole antenna patterns is connected to the power supply circuit pattern. Forming a dipole antenna pattern shorter in length than these dipole antenna patterns in parallel and adjacent to each of the dipole antenna patterns in the first and second printed dipole antennas,
The omnidirectional antenna according to claim 1, wherein each of the short dipole antenna patterns is separated from the power supply circuit pattern. A part of each dipole antenna pattern in the first and second printed dipole antennas is cut out, and a dipole antenna pattern having a shorter length than these dipole antenna patterns is formed in each of these dipole antenna patterns;
The omnidirectional antenna according to claim 1, wherein each of the short dipole antenna patterns is connected to the power supply circuit pattern. First and second printed dipole array antennas formed by cascading a plurality of pairs of parallel dipole antenna patterns in a longitudinal direction of a rectangular dielectric substrate;
A printed power supply circuit formed on a dielectric substrate with a parallel power supply circuit pattern connected to each of the dipole antenna patterns of the first and second printed dipole array antennas,
The pair of dipole antenna patterns in the first and second printed dipole antennas are formed so as to be along the longitudinal axis of the dielectric substrate of those antennas and to be symmetrical about the axis. ,
Dielectric substrates of the first and second printed dipole array antennas are arranged in parallel so that the respective dipole antenna patterns formed thereon face each other, and the first and second printed dipole arrays are arranged. The first and second sides of one side and the other side of the dielectric substrate of the printed power supply circuit are opposed so that the dielectric substrate of the antenna and the dielectric substrate of the printed power supply circuit form an H-shaped cross section. 2. The omnidirectional antenna according to claim 2, wherein the printed dipole array antenna is positioned on the longitudinal axis of the dielectric substrate . Forming dipole antenna patterns shorter in length than these dipole antenna patterns in parallel and adjacent to the side of each dipole antenna pattern in the first and second printed dipole array antennas, respectively;
The omnidirectional antenna according to claim 5, wherein each of the short dipole antenna patterns is connected to the power supply circuit pattern. Forming dipole antenna patterns shorter in length than these dipole antenna patterns in parallel and adjacent to the side of each dipole antenna pattern in the first and second printed dipole array antennas, respectively;
The omnidirectional antenna according to claim 5, wherein each of the short dipole antenna patterns is separated from the power supply circuit pattern. A part of each dipole antenna pattern in the first and second printed dipole array antennas is cut out, and a dipole antenna pattern having a shorter length than these dipole antenna patterns is formed in each of the dipole antenna patterns. ,
The omnidirectional antenna according to claim 5, wherein each of the short dipole antenna patterns is connected to the power supply circuit pattern. 9. The omnidirectional antenna according to claim 5, wherein a shield post pattern is formed between each pair of dipole antenna patterns in the first and second printed dipole array antennas. The power supply circuit pattern of the printed power supply circuit includes a ground pattern along a longitudinal direction of a substrate of the power supply circuit, and a cover plate made of a conductive material is disposed to face the ground pattern. 10. The omnidirectional antenna according to claim 5, wherein a power supply cable is provided in a space formed between the ground patterns.

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