JP2000223941A - Transmission antenna device and broadcasting tower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an omnidirectional transmission antenna device which is suitable for transmitting plural broadcast waves in different radio wave frequencies. SOLUTION: Antenna structure is realized as if one multi-surface combination antenna is formed in appearance by providing plural (N) antenna elements A (A1 to A4), B (B1 to B4) arranged at intervals of equivalent angles on a cylindrical surface C with radius R respectively and alternately arranging the respective antenna elements A, B of first and second multi-surface combination antennas 10, 20 to which mutually different radio frequencies are allocated on the cylindrical surface C by this device. And two broadcast waves with different frequencies are omnidirectionally radiated respectively by suppressing interference between the multi-surface combination antennas by performing phase different power feed to the antenna elements A, B by providing them with a phase difference determined by each of the multi-surface combination antennas 10, 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an omnidirectional transmitting antenna device and a broadcasting tower suitable for transmitting a plurality of broadcast waves having different radio frequencies.

[0002]

2. Description of the Related Art Broadcast waves from radios and televisions are radiated from, for example, an omni-directional transmission antenna installed on a broadcast tower. It is desirable to install this type of transmitting antenna at a position where the ground clearance is as high as possible in order to secure a radio wave reach distance. In addition, since it is desirable for the side receiving a plurality of broadcast waves that the arrival directions of the respective broadcast waves are uniform, the transmitting antennas of the respective broadcast waves are generally mounted on the same broadcast tower.

[0003]

The broadcast tower, as shown in FIG. 10, comprises a tower-shaped skeletal frame body 1 made up of steel frames and a pole portion 2 provided vertically at the upper end thereof. An omnidirectional transmission antenna such as the turn style antenna 3 is exclusively attached to the pole section 2. However, the number of transmitting antennas that can be attached to the pole part 2 is naturally limited because it is limited by the length of the pole part 2.

Therefore, it has been attempted to mount a transmitting antenna composed of a multi-plane composite antenna 4 on the peripheral surface of the upper end of the skeletal frame body 1 having a relatively small cross section. The multi-plane composite antenna 4 is configured by arranging a plurality of antenna elements such as a twin loop antenna at equal angular intervals around the skeletal frame body 1 and combining radio waves radiated from each antenna element in the air. The antenna obtains an omnidirectional radiation pattern of a radio wave, and is called a four-plane combined antenna, an eight-plane combined antenna, or the like, depending on the number of surfaces on which the antenna elements are arranged. However, even when such a multi-plane antenna 4 is used in combination, the number of transmitting antennas that can be mounted on a broadcasting tower is limited, so that a problem remains in dealing with a large number of broadcast waves expected to increase in the future.

The present invention has been made in view of such circumstances, and has as its object to transmit a plurality of broadcast waves having different radio frequencies, for example, suitable for installation in a limited facility space above a broadcast tower. It is another object of the present invention to provide an omnidirectional transmission antenna device suitable for the above.

[0006]

In order to achieve the above object, a transmitting antenna apparatus according to the present invention comprises a plurality of antenna elements arranged at equal angular intervals on a cylindrical surface having a radius R. A plurality of multi-plane composite antennas that combine radiated radio waves in the air to obtain an omni-directional radiation pattern of the radio waves, wherein the plurality of multi-plane composite antennas are respectively assigned to different radio frequencies. Each antenna element
It is characterized by being arranged cyclically in a predetermined order on the cylindrical surface.

Preferably, the plurality of multi-plane composite antennas each include three or more antenna elements having the same number of planes, and all of these antenna elements are arranged on the cylindrical surface. Are arranged at equal angular intervals. Specifically, for example, two 4
By arranging the above-described antenna elements of the surface-synthesized antenna alternately at equal angular intervals, an antenna structure is realized as if apparently forming one 8-plane synthesized antenna, and a radio frequency different from the antenna structure is obtained. It is characterized in that two broadcast waves are radiated omnidirectionally.

According to a preferred aspect of the present invention, a plurality of antenna elements constituting each of the plurality of multi-plane composite antennas are positioned by giving a phase difference determined for each of the multi-plane composite antennas. It is characterized in that phase difference power is supplied, thereby preventing a radio wave from wrapping between adjacent antenna elements. Further, in a preferred aspect of the present invention, as described in claim 4, a plurality of antenna elements constituting each of the multi-plane composite antennas are arranged in parallel with a plurality of antenna elements, for example, a dual loop antenna, along a flat reflector. Are realized as n-element double-loop antennas arranged in a matrix, and these antenna elements are arranged with a predetermined offset in the tangential direction of the cylindrical surface, thereby combining in the air with radio waves radiated from the antenna elements. It is characterized in that an excellent omnidirectional radiation pattern is obtained by preventing a drop in the radio wave intensity at the boundary with the radio wave.

Further, the present invention provides, as set forth in claim 5,
By providing the plurality of multi-plane composite antennas to which different radio frequencies are assigned coaxially in multiple stages, and forming a multi-stage multi-plane composite antenna for each radio frequency,
It is characterized by increasing the antenna gain. At this time, for example, it is also possible to make a contrivance such as setting the surfaces of the antenna elements of the multi-plane combined antenna in each stage in mutually different directions.

[0010] Each of the multi-plane composite antennas has an 8
Preferably, it is realized as a plane or 9-plane composite antenna, or as a 15-plane or 16-plane composite antenna.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a transmitting antenna device according to an embodiment of the present invention will be described with reference to the drawings. FIG.
Is a schematic configuration diagram of a transmission antenna device according to an embodiment,
Here, as the first and second multi-plane composite antennas, as shown in FIG.
An omnidirectional first four-plane combined antenna 10 provided with (A1, A2, A3, A4) and four antenna elements B (B1,
B2, B3, B4) and a non-directional second four-plane combined antenna 20 having the same peripheral surface and being coaxially arranged. That is, the first and second four-plane combined antennas 10, 2
0 indicates that each of the four antenna elements A1, A2, A3, A4, B
1, B2, B3, and B4 are equiangularly spaced (90 ° apart) on a cylindrical surface C having a radius R with the antenna surface facing outward.
, And especially each of the above antenna elements A
(A1, A2, A3, A4), B (B1, B2, B3, B4) at 45 °
It is configured by being alternately arranged at intervals. The cylindrical surface C
Is a spatially defined surface.

Thus, the first and second four-plane combined antennas 10 and 20 are respectively provided with phase shifters 11, 12, 13, 14,
It is set so as to be fed with phase difference via 21, 22, 23 and 24 and to transmit broadcast waves of different radio frequencies fa and fb, respectively. In the figure, reference numerals 15 and 25 denote transmitters of broadcast waves composed of the radio wave frequencies fa and fb. Each of the antenna elements A and B constituting each of the four-plane composite antennas 10 and 20 is shown in FIG.
As shown in (a) and (b), the plane configuration and the cross-sectional configuration, basically, on a flat plate-like reflector 31 having a main surface formed by bending both longitudinal edges thereof at approximately 45 °, A double-loop antenna 33 having four arc-shaped loop antenna element portions 32 each having a circumference L of substantially one wavelength λ of each of the radio wave frequencies fa and fb is provided in parallel with the main surface. The radio wave radiated from the main surface 33 is transmitted with unidirectionality in a direction perpendicular to the main surface.
In the drawing, reference numeral 34 denotes a protective cover (a radome) provided to cover the dual loop antenna 33. This protective cover 3
4 protects the dual loop antenna 33 from rain and wind, snow, dust, and the like.

As shown in FIGS. 4A and 4B, by providing two or three two-element double loop antennas 33 in parallel and providing a plurality of double loop antennas 33 in parallel, the antenna elements A and B The directivity of the radiated radio wave may be enhanced. Of course, it is also possible to realize the antenna elements A and B using not only the two-element double-loop antenna 33 but also a one-element two-loop antenna, a four-element double-loop antenna, or the like. By attaching the protective covers 34 to both ends of the reflector 31, it is possible to reduce the overall unevenness.

Here, the directivity of a four-plane combined antenna constituted by arranging four antenna elements A and B at equal angular intervals will be briefly described. As shown schematically in FIG. The four antenna elements arranged outwardly at 90 ° intervals radiate their radio waves in a direction perpendicular to the antenna surface (main surface) to form main lobes M1, M2, M3, and M4. At the same time, each antenna element forms combined lobes C12, C23, C34, and C41 in the middle direction of each of the main lobes M1, M2, M3, and M4 by combining radio waves radiated from adjacent antenna elements. The drop of the radio wave intensity in the direction between the direction of the main lobe and the direction of the synthetic lobe is 3 dB or less, which is generally called an omnidirectional pattern.
As a whole, a non-directional radio wave radiation pattern in which the radio wave intensity in all directions is substantially uniform is realized.

In general, a multi-plane (N-plane) composite antenna having N antenna elements has each antenna element on a cylindrical surface C having a radius R of [2π / N] as shown in FIG. It is realized by being arranged at intervals. At this time, the radius R forming the cylindrical surface C is determined by the size of the column portion of the broadcasting tower on which the multi-plane (N-plane) composite antenna is installed, for example, the size of the pole section or the skeleton frame body having a square cross section (one side). In consideration of the length W), the size is determined so as to include the skeletal frame body, include dimensions necessary for mounting each antenna element, and to arrange the antenna elements as close as possible. This is because, in general, the smaller the radius R forming the cylindrical surface C is, the more the above-mentioned drop in the radio field intensity can be reduced.

Each antenna element is connected to the cylindrical surface C.
Are displaced (offset) by do = λ / {N · sin (2π / N)} in the tangential directions of the above, and the above-mentioned radio wave intensity of the broadcast wave which is synthesized between adjacent antenna elements and has a non-directional radiation characteristic May be reduced.

Thus, the transmitting antenna apparatus according to the embodiment of the present invention has different radio frequency f
The antenna elements A and B of the first and second four-plane composite antennas 10 and 20 to which a and fb are assigned are alternately arranged at an angle of 45 °. It is configured as follows. In other words, the first and second four-sided composite antennas 1 are arranged at positions where the eight antenna elements constituting the eight-sided composite antenna are arranged.
By alternately arranging the antenna elements A and B constituting 0 and 20, a transmission antenna device is realized.

As described above, each of the antenna elements A and B of the first and second four-plane combined antennas 10 and 20 are connected to the phase shifters 11, 12, 13, 14, 21, 22, 23, and 2 as described above.
4 radiate broadcast waves having different radio frequencies, and radiated radio waves are combined to obtain an omnidirectional radiation pattern. In particular, by the above-described phase difference feeding, a predetermined phase difference is given to radio waves circulating between the adjacent antenna elements A and B, respectively, thereby preventing interference between the antenna elements A and B.

More specifically, for example, the four antenna elements A constituting the first four-sided combined antenna 10 are fed with a phase difference of [2π / 4] to be fed, and the second four-sided combined antenna 20 is provided. Are supplied with a phase difference of [0] to each of the four antenna elements. Incidentally, since the first and second four-plane combined antennas 10 and 20 are respectively arranged evenly, the first four-plane combined antenna 1
The coupling phase in the space between 0 and the second four-plane combined antenna is the same between the antenna elements A and B.
As a result, the first and second four-plane combined antennas 10, 2
0, the radio wave frequency fa radiated from the first four-plane combined antenna 10
The component of the radio frequency fa which is wrapped around the planar composite antenna 20 and received and combined and output is zero [0] because it is composed by the phase difference in each antenna element A of the first four-plane composite antenna 10. . Similarly, the first radio wave frequency fb radiated from the second
The component of the radio wave frequency fb, which wraps around to the four-plane combined antenna 10 and receives power and combines and outputs, is also zero [0].

That is, adjacent antenna elements A and B
By giving a predetermined phase difference [2π / 4] to the radiated radio waves circling through each other via the antenna, the broadcast wave of the radio wave frequency fa radiated from the first four-plane combined antenna 10 has the second four planes. The four antenna elements B1,
The component fa that is wrapped around B2, B3, and B4 and received power, respectively.
The phases of 1, fa2, fa3, and fa4 are [0], [π / 2],
[Π] and [3π / 2] are different from each other, and the combined output component is set to zero [0]. Similarly, the broadcast wave of the radio wave frequency fb radiated from the second four-sided composite antenna 20 wraps around the four antenna elements A1, A2, A3, A4 of the first four-sided composite antenna 10 and receives power respectively. So that the phases of the components fb1, fb2, fb3, fb4 are different from [0], [π / 2], [π], [3π / 2], and the combined output component is zero [0]. Is set. That is, as described above, the first and second four-sided combined antennas 10 and 20 are fed with a phase difference, and a predetermined phase difference is given between adjacent antenna elements, thereby providing the first and second four-sided combined antennas. 10,20
Interference between them is prevented.

Thus, according to the transmitting antenna apparatus in which the interference between the adjacent antenna elements A and B is suppressed in this manner, the first and the second antenna elements A and B are arranged so as to form an eight-plane combined antenna. From the second four-plane combined antennas 10 and 20, radio wave frequencies fa and fb are mutually transmitted.
Can be transmitted independently and efficiently in an omni-directional pattern, respectively.
In particular, since the antenna elements A and B constituting the first and second four-plane combined antennas 10 and 20, respectively, are alternately arranged on the same cylindrical surface C, it is possible to obtain a compact antenna shape as a whole. it can. Therefore, even when the space for antenna facilities in a broadcast tower or the like is limited, it is possible to effectively transmit a large number of broadcast waves having different radio frequencies by effectively using the limited space.

Further, according to the transmission antenna device configured as described above, for example, two different radio wave frequencies fa and fb are used.
The first and second four-plane combined antennas 10 and 20 transmitting two broadcast waves can be arranged at the same antenna height (ground height). Furthermore, even when the installation space of the antenna in the broadcast tower is limited in the height direction, since the transmitting antenna device having the above configuration can be provided for each antenna mounting position having a different height, more broadcast waves can be transmitted. The effect that transmission becomes possible etc. is produced.

Incidentally, the antenna elements A and B in the first and second four-plane combined antennas 10 and 20 are respectively arranged by alternately arranging the antenna elements A and B.
The spacing between them will be large. As described above, when the distance between the antenna elements is large, the drop of the radio wave intensity between the main lobe and the combined lobe becomes large. However, regarding the influence, for example, the first and second multi-plane combined antennas 10 and 20 are
Surface antennas, etc. are further diversified, sharpening the directivity of each antenna element A, B, and offsetting the mounting position of antenna elements A, B as described above, causing a drop in strength on the radio wave synthesis surface. Can be reduced, so that it can be suppressed to a level that does not substantially cause a problem. Therefore, the same cylindrical surface C
Each of the first and second four-plane combined antennas 10 and 20 alternately arranged on the upper side is provided with a four-wave antenna for a single wave having a conventional general simple configuration.
Antenna characteristics comparable to those of the planar composite antenna can be realized.

In the above-described embodiment, an example is shown in which the first and second multi-plane composite antennas 10 and 20 are each realized as a 4-plane composite antenna.
In order to obtain an omnidirectional pattern with a small drop in radio field intensity, it is generally advantageous to increase the number of planes. On the other hand, as the number of surfaces increases, the diameter of the antenna mounting surface on which a plurality of antenna elements are arranged increases. In particular, when the first and second multi-plane antennas 10 and 20 are realized in the same cylindrical plane as described above, it is necessary to arrange substantially twice the number of antenna elements in the same cylindrical plane, It cannot be denied that the diameter of the antenna mounting surface increases.

FIG. 9 shows the relationship between the maximum drop amount of the radio wave intensity in the radiation pattern when the diameter (wavelength ratio) of the antenna mounting surface of the single 8-plane combined antenna is variously changed. X indicates the area of the diameter of the antenna mounting surface on which two types of eight-plane composite antennas can be arranged in the same cylindrical surface as described above. That is, in this case, by setting the diameter of the antenna mounting surface to be approximately 3.4λ or more, the first and second multi-plane synthesized antennas 10 and 20 composed of the eight-plane synthesized antenna are aligned. And can be realized in the same horizontal plane.

In this case, in order to obtain an omnidirectional pattern characteristic in which the drop of the radio wave intensity is reduced, it is desirable that the diameter of the antenna mounting surface be approximately 3.5λ, but the size of each antenna element is reduced. In consideration of this, it cannot be denied that the installation interval between adjacent antenna elements is reduced. However, as shown in the characteristics shown in FIG. 9, in this case, even if the diameter of the antenna mounting surface is set to about 5.0λ, it is possible to realize substantially the same omnidirectional pattern characteristics. Therefore, in the case of realizing an eight-plane combined antenna, for example, if the diameter of the antenna mounting surface is set to about 5.0λ, it is possible to provide a good space with a small drop in the radio wave intensity while allowing a sufficient space between adjacent antenna elements. An omnidirectional pattern can be obtained.

Considering the multi-plane composite antenna based on this viewpoint, one side of the skeleton frame 1 at the upper end of the broadcast tower having a relatively small cross section is 250 to 2 pieces.
In a case where the antenna has a square size of about 80 cm, the diameter (diameter) of the antenna mounting surface is actually 440 to 46.
What is necessary is just to secure about 0 cm. Therefore, the wavelength λ is 550 m
In order to realize a transmitting antenna apparatus for transmitting a broadcast wave in the UHF band of about m, the first and second multi-plane composite antennas described above are realized as 8-plane or 9-plane composite antennas, respectively, for a total of 16 planes or 18 planes. If the antenna elements on the surface are arranged in a ring shape, it is possible to compactly realize a broadcast transmitting antenna device having a small omnidirectional pattern characteristic with a small drop in radio field intensity. If there is no restriction on the space for mounting the antenna device, it goes without saying that the diameter of the antenna mounting surface may be set to about 3.5λ.

Further, one side of the frame 1 is 700 cm.
When the antenna has a relatively large square shape, the diameter (diameter) of the antenna mounting surface is 1700 cm.
What is necessary is just to secure a degree. In this case, the wavelength λ is 550 mm
If the first and second multi-plane composite antennas for the UHF band are realized as an eight- or nine-plane composite antenna as described above, the installation intervals between the antenna elements are widened, and the amount of drop in the radio wave intensity is increased. Therefore, in this case, the first and second multi-plane composite antennas described above are realized as a 15-plane or 16-plane composite antenna, respectively, and a total of 30 or 32 plane antenna elements are arranged in an annular configuration. In addition, it is possible to obtain an omnidirectional pattern characteristic with a small drop in radio field intensity by appropriately setting the installation interval between the antenna elements.

Further, according to the broadcasting tower incorporating such a transmitting antenna device, a plurality of antenna elements are provided compactly in an annular shape, and the surface thereof is covered with a protective cover 43 to form a cylindrical shape with little unevenness. As a result, it is possible to reduce the heavy load on rain pressure. At the same time, the wind pressure load on the broadcasting tower can be reduced. Therefore, it is possible to realize a broadcast tower that is stable in intensity, even though a transmission antenna device capable of transmitting a large number of broadcast waves is incorporated.

The present invention is not limited to the above embodiment. In the embodiment, a transmission antenna device having an apparently eight-plane synthesized antenna composed of two four-plane synthesized antennas 10 and 20 is realized. However, as described above, two five-plane synthesized antennas are alternately arranged. Placed, apparently a transmission antenna in the form of a 10-plane composite antenna, or two 6-plane composite antennas are arranged alternately,
It is also possible to use a transmitting antenna device or the like having the shape of a twelve-surface composite antenna. Each antenna element of three four-plane composite antennas to which three different radio frequencies fa, fb, and fc are assigned is cyclically arranged in a predetermined order, and is apparently used as a transmission antenna apparatus or the like having the shape of a 12-plane composite antenna. It is also possible to realize. In short, each of the M antenna elements constituting each of the M N-plane combined antennas to which different radio frequencies are assigned is arranged on a cylindrical surface C having a predetermined radius R at an angular interval of [2π / M · N] in a predetermined order. It is sufficient to arrange in a cyclic manner.

In order to increase the transmission power of each multi-plane composite antenna, as shown in FIGS. 7A and 8A, for example, the first and second four-plane composite antennas are alternately arranged as described above. A plurality of transmission antenna devices arranged in a vertical direction are coaxially arranged in multiple stages (three to five stages) to form a multi-stage multi-plane composite antenna (three-stage four-plane composite antenna or the like), and the antenna area is determined for each radio frequency. The antenna gain should be widened to increase the antenna gain. In this case, the directions of the antenna elements A and B in each stage are alternately switched as shown in FIG. 7B, or are sequentially shifted at a pitch of 1/2 of the element arrangement interval as shown in FIG. 8B. Therefore, it is also effective to change the direction in which the radio wave intensity of the broadcast wave of each of the radio wave frequencies fa and fb falls on the combining surface. That is, it is preferable to set the total radiation intensity of the radio waves obtained by combining the radio waves obtained from the four-plane combined antennas at each stage in the vertical direction so as to be substantially uniform in all directions. Further, if the directions of the antenna elements in the respective stages are made different in this manner, it is possible to suppress the deviation (variation) in the directivity of the radio wave frequencies fa and fb transmitted from the transmitting antenna device with respect to the vertical direction. The effect is achieved.

Further, the first and second four-plane combined antennas 10 and 20 can be shared for transmitting a plurality of radio waves, respectively. For example, three broadcast waves having different frequencies for each of the four-sided composite antennas 10 and 20,
Alternatively, four broadcast waves may be shared and transmitted. In this case, in order to increase the permissible power for radio waves shared by each antenna, it is necessary to devise, for example, making the feed line one turn thicker. Also, as described above, depending on the diameter of the antenna mounting surface determined according to the size of the antenna mounting site,
What is necessary is just to set the number of antenna elements constituting each multi-plane composite antenna so that the drop of the radio field intensity is minimized. In addition, the present invention can be variously modified and implemented without departing from the gist thereof.

[0033]

As described above, according to the present invention, apparently, a plurality of antenna elements forming one multi-plane combined antenna transmit, for example, the first and second antennas respectively transmitting two broadcast waves having different radio frequencies. Since the antenna functions as a multi-spectrum composite antenna, the overall shape of the transmitting antenna device can be made compact, and effects such as easy installation in a broadcast tower or the like can be obtained.

In particular, since the antenna elements constituting each of the plurality of multi-plane composite antennas are fed with a predetermined phase difference and fed with a phase difference, the interference between the multi-plane composite antennas is suppressed, and each antenna functions effectively. And the like. And practically,
If each multi-plane composite antenna is realized as an 8-plane or 9-plane composite antenna or as a 15-plane or 16-plane composite antenna, a compact transmitting antenna device having an omni-directional pattern excellent in radio wave radiation characteristics can be constructed.

[Brief description of the drawings]

FIG. 1 is an arrangement diagram of antenna elements showing a schematic configuration of a transmission antenna device according to an embodiment of the present invention.

FIG. 2 is an equivalent configuration diagram of the transmission antenna device shown in FIG.

FIG. 3 is a diagram showing a configuration example of an antenna element constituting a multi-plane combined antenna.

FIG. 4 is a diagram showing another configuration example of the antenna element.

FIG. 5 is a diagram conceptually showing a radio wave radiation pattern of a four-plane combined antenna.

FIG. 6 is a diagram showing a general arrangement example of a plurality of antenna elements constituting a multi-plane combined antenna.

FIG. 7 is a diagram showing an arrangement example of antenna elements constituting a multi-stage multi-plane combined antenna.

FIG. 8 is a diagram showing another example of arrangement of antenna elements constituting a multi-stage multi-plane combined antenna.

FIG. 9 is a diagram showing the relationship between the radiation pattern and the maximum dip in the radiation pattern when the diameter (wavelength ratio) of the antenna mounting surface of the single 8-plane combined antenna is variously changed.

FIG. 10 is a diagram illustrating an example of a broadcast tower on which a broadcast transmitting antenna is installed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 First four-sided combined antenna 11, 12, 13, 14 Phase shifter (for phase difference feeding) 15 Transmitter (radio frequency fa) 20 Second four-sided combined antenna 21, 22, 23, 24 Phase shifter (For phase difference feeding) 25 Transmitter (radio frequency fb) 31 Reflector 32 Loop antenna element 33 Dual loop antenna A1, A2, A3, A4 Antenna element B1, B2, B3, B4 Antenna element C Cylindrical surface of radius R

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takao Kanai 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Kazuo Shigeta 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd. (72) Inventor Reiji Fukuhara 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd.

Claims (6)

[Claims] 1. A multi-plane antenna having a plurality of antenna elements arranged in a ring shape on a cylindrical surface having a radius R, and combining radio waves radiated from each antenna element to obtain an omnidirectional radiation pattern of the radio waves. A transmitting antenna device comprising: a plurality of multi-plane combined antennas to which different radio frequencies are assigned, wherein the antenna elements are arranged in a predetermined order on the cylindrical surface. 2. The multi-plane antenna according to claim 1, wherein the plurality of multi-plane antennas each include three or more antenna elements having the same number of planes, and all of these antenna elements are arranged at equal angular intervals on the cylindrical plane. The transmitting antenna device according to claim 1, wherein 3. The method according to claim 1, wherein the plurality of antenna elements constituting each of the plurality of multi-plane antennas are supplied with a phase difference determined for each of the multi-plane antennas and fed with a phase difference. The transmitting antenna device as described in the above. 4. A plurality of antenna elements constituting each of the multi-plane composite antennas are configured by arranging a plurality of n-element antennas in parallel along a flat reflector,
The transmitting antenna apparatus according to claim 1, wherein a predetermined offset is provided in a tangential direction of the cylindrical surface, and the predetermined offset is provided. 5. A multi-stage multi-plane antenna according to claim 1, wherein said plurality of multi-plane composite antennas to which different radio frequencies are assigned are provided coaxially in multiple stages, respectively, to form a multi-stage multi-plane composite antenna for each radio frequency. 3. The transmitting antenna device according to claim 1. 6. A broadcasting tower comprising the transmitting antenna device according to claim 1 at a predetermined ground height.