JP2013157707A - Shaped-beam antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shaped-beam antenna that can form a main lobe in the desired direction in a wide range regardless of its simple structure, and that is devoted to radio transmission.SOLUTION: A shaped-beam antenna comprises a first antenna element the length of which is equal to the sum of a half wave-length (λ/2) and a real number α ((-λ/2)<α<(λ/2)) and a second antenna element the length of which is equal to difference between the half wave-length (λ/2) and the real number α. The first antenna element is formed as a cylindrical body to which a power supply line used for supplying power to the first antenna element and the second antenna element is slackly inserted or loosely inserted and in which a prescribed place of its inner wall becomes a first power supply point. The second antenna element is formed in a longitudinal direction, and includes a hole or a communication hole about which its bottom part or a prescribed place of the inner wall becomes a second power supply point forming a pair with the first power supply point.

Description

  The present invention relates to a shaped beam antenna that forms a main lobe in a desired direction and is used for wireless transmission.

  Conventionally, an antenna capable of forming a main lobe in a desired direction includes, for example, a sleeve having a length of (λ / 2) to (22λ / 32), and a length as shown in Patent Document 1 described later. There is a “sleeve-loaded beam tilt antenna” in which a sleeve of (λ / 4) and a super top having an upper end at a position separated from the upper end by (λ / 2) are vertically stacked.

  Such a beam tilt antenna has a total length (height) of 1.5λ or more, and the length of the sleeve at the upper end is adjusted, so that the direction of the main lobe is set in a desired direction on the vertical plane. Is set.

  Further, the beam tilt antenna is configured as a collinear antenna in which sleeves are stacked in multiple stages, and the super-top disposed at the lower end prevents high-frequency current from riding on the outer skin of the feed path that extends further downward.

  Therefore, high gain can be achieved by maintaining the omnidirectionality in the horizontal direction and narrowing the directivity in the vertical plane.

JP-A-7-66618

  By the way, in the conventional beam tilt antenna described above, power supply with a predetermined phase difference is performed in series with respect to two or more radiating elements (hereinafter, power supply performed in this way is referred to as “series power supply”). Thus, the main lobe is tilted upward or downward from the horizontal direction.

  However, the frequency band in which the desired gain and directivity can be obtained has become narrow because the form of feeding is the series feeding.

  In addition, collinear antennas are generally not suitable for applications in which a beam should be formed in a specific direction or various directions over a wide frequency band, and because the structure is relatively complicated and the dimensions are large, In many cases, it was difficult to adopt due to restrictions on mountability, cost, etc. at the site to be installed.

  An object of the present invention is to provide a shaped beam antenna capable of forming a main lobe in a desired direction over a wide band despite its simple structure.

  In the first aspect of the invention, the length of the first antenna element is equal to the sum of the half wavelength (λ / 2) and the real number α ((−λ / 2) <α <(λ / 2)). . The length of the second antenna element is equal to the difference between the half wavelength (λ / 2) and the real number α. In the first antenna element, a feeding line provided for feeding power to the first antenna element and the second antenna element is loosely or loosely inserted, and a predetermined portion of the inner wall is a first feeding point. It is configured as a cylinder. The second antenna element is formed in a longitudinal direction and has a hole or a communication hole in which a predetermined portion of the bottom or inner wall is a second feeding point that is paired with the first feeding point.

  In other words, the feed line realizes feeding to these antenna elements without being positioned outside either the first antenna element or the second antenna element. In addition, the direction of the main lobe formed under such feeding is larger as the difference in length (= | α |) between the first antenna element and the second antenna element is larger. Among them, it is biased in the direction in which the short antenna element is located.

  In the invention according to claim 2, the length of the first antenna element is equal to the sum of the half wavelength (λ / 2) and the real number α ((−λ / 2) <α <(λ / 2)). . The length of the second antenna element is equal to the difference between the half wavelength (λ / 2) and the real number α. The first antenna element is disposed inside, and a first antenna terminal of a device that transmits or receives a radio signal having the wavelength λ is used as a first feeding point at a predetermined position on the inner wall of the interior. It is configured as a connected cylinder. The second antenna element is formed in the longitudinal direction and is connected to the second antenna terminal of the device as a second feeding point where a predetermined portion of the bottom or inner wall is paired with the first feeding point Hole or communication hole.

  That is, the device arranged inside the first antenna element realizes power feeding to these antenna elements via a feeding path that is not located outside either of the first antenna element and the second antenna element. . In addition, the direction of the main lobe formed under such feeding is larger as the difference in length (= | α |) between the first antenna element and the second antenna element is larger. Among them, it is biased in the direction in which the short antenna element is located.

  According to a third aspect of the present invention, in the shaped beam antenna according to the first aspect, the first feeding point and the second feeding point are the feeding line, the first antenna element, and the first feeding point. It is set at a location where impedance matching with the second antenna element is achieved.

  That is, a reduction in bandwidth and gain due to impedance mismatch between the shaped beam antenna and the feeding path according to the present invention is avoided.

  In the invention according to claim 4, in the shaped beam antenna according to claim 2, the first feeding point and the second feeding point are the first antenna terminal and the second antenna terminal of the device. And where the impedance matching between the first antenna element and the second antenna element is achieved.

  That is, a reduction in bandwidth and gain due to impedance mismatch between the shaped beam antenna and the feeding path according to the present invention is avoided.

In the invention according to claim 5,
The shaped beam antenna according to any one of claims 1 to 4, wherein the first antenna element and the second antenna element have a desired width of a main lobe formed by the dipole antenna. It is arranged with a value distance and posture.

  That is, the width of the main lobe is set to a desired value by setting the relative distance and posture of the first and second antenna elements without increasing the number of components.

According to the present invention, although the configuration is simple, the first and second antenna elements are fed in parallel to secure a wide band, and the directivity and gain due to the shielding of the feed line are also increased. The beam is formed in the desired direction without any degradation.
In the present invention, a wireless transmission path is stably formed in a desired band and direction in accordance with the wavelength λ of a wireless signal to be transmitted or received.
Therefore, in the radio transmission system and the radio communication system to which the present invention is applied, reliability is improved and stable in addition to transmission quality and communication quality without being restricted by cost, mountability, and placement conditions. Maintained.

It is a figure which shows 1st embodiment of this invention. It is a figure which shows the impedance matching achieved by this embodiment. It is a figure which shows the directivity of the perpendicular direction in this embodiment. It is a figure which shows 2nd embodiment of this invention. It is a figure which shows the gain achieved with a reflector, and the directivity on a horizontal surface.

FIG. 6 shows the width of the main lobe achieved by the reflector. It is a figure which shows 3rd embodiment of this invention. FIG. 6 is a diagram showing gain and directivity achieved by a grid-like reflector. FIG. 6 shows the width of the main lobe achieved by the grid-like reflector.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[First embodiment]
FIG. 1 is a diagram showing a first embodiment of the present invention.
This embodiment is composed of elements (1) to (7) listed below.

(1) L _T (= (λ / 2) for a wavelength λ and a real number α (| α | <(λ / 2)) (for example, a value of “0.01” to “0.02”) ) -Α) cylindrical conductor 11T
(2) The length is given as a product of the wavelength λ (a product of a coefficient (for example, a value of “0.8” to “0.99”) determined according to the diameter of the cylindrical conductors 11T and 11B) and a real number. Cylindrical conductor 11B which is L _B (= (λ / 2) + α) with respect to α

(3) In a state orthogonal to the central axis of the hollow portion of the cylindrical conductor 11T, the side wall is formed in a shape and size that can be loosely fitted (inserted) into the inner wall of the hollow portion, and the center of the top portion and the bottom portion is A disk conductor 12T that has a through hole 12Th that is formed between and has a through hole 12Th that is set to a value that allows a center conductor of a coaxial cable 13 that will be described later to be inserted (loosely fitted).

(4) In a state orthogonal to the central axis of the hollow portion of the cylindrical conductor 11B, the side wall is formed in a shape and size that can be loosely fitted (inserted) into the inner wall of the hollow portion, and the center of the top portion and the bottom portion is A disk conductor 12B-1 having a through-hole 12Bh-1 formed between them and having a dimension and a shape set to a value in which an insulator of a coaxial cable 13, which will be described later, is inserted (loosely fitted) and has a thickness t.

(5) In a state perpendicular to the central axis of the hollow portion of the cylindrical conductor 11B, the side wall is formed in a shape and size that can be loosely fitted (inserted) into the inner wall of the hollow portion, and the center of the top portion and the bottom portion is A disk conductor 12B-2 having a through hole 12Bh-2 formed therebetween and set to a value that allows the size and shape to be loosely fitted to the outer conductor of the coaxial cable 13 and has a thickness t.

(6) One end and the vicinity thereof are pre-processed to set the state shown in (6-1) to (6-3) below, and the other end is connected to the antenna terminal of the wireless device not shown. Cable 13
(6-1) In the section S1 from the end P0 of the coaxial cable 13 to the point P1 that is separated in the longitudinal direction over the length L1, the jacket, the outer conductor, and the insulator (dielectric material such as polyethylene) of the coaxial cable 13 Is removed), only the central conductor is exposed. In the section S1, for example, as shown in the upper part of FIG. 1A, only the outer conductor may be removed and the insulator may be left together with the central conductor.

(6-2) In the section S2 from the point P1 to the point P2 further separated by the thickness (≈t) of the disk conductor 12B-1, the outer conductor is exposed by removing the outer cover of the coaxial cable 13, A corresponding portion of the outer conductor is folded back along the cut surface of the jacket of the coaxial cable 13.

(6-3) In the section S3 from the point P2 to the point P3 further separated over the predetermined length L2, the outer cover of the coaxial cable 13 is removed. In the section S3, the outer cover of the coaxial cable 13 does not necessarily have to be removed over the entire area as shown in the lower part of FIG. 1A. Further, for example, at the point P3, the disk conductor 12B -2 (through hole 12Bh-2), if the outer conductor of the coaxial cable 13 can be connected or loosely fitted under some method or mechanical configuration, it can be removed only in the vicinity of the point P3, or It does not have to be removed at all.

As shown in FIG. 1, the lengths L1 and L2 correspond to the openings _{AT on} the bottom surface of the cylindrical conductor 11T in a state where the axes of the cylindrical conductors 11T and 11B are aligned on a common virtual straight line. and with respect to the distance d between the aperture a _B at the top of the circular conductor 11B, for example, it is preset to the value indicated by the following formula.

L1 = (5λ / 48) + d + t
= T + L _T + d + L _B
= T + ((λ / 2) / 12) + d + ((λ / 2) / 8)
L2 = (3λ / 16) + (α / 2)
= (((Λ / 2) + α) / 2) -L B
= (((Λ / 2) + α) / 2)-((λ / 2) / 8)

Here, the following points (a), (b), and (c) along the axes of the cylindrical conductors 11T and 11B are defined as points X0, X1, and X2, respectively.
(a) Point X0: Point separated from the bottom of the cylindrical conductor 11T by (λ / 24 = (λ / 2) / 12 = L _T )
(b) Point X1: A point separated from the top of the cylindrical conductor 11B by (λ / 16 = (λ / 2) / 8 = L _B )
(c) Point X2: Point separated from the top of the cylindrical conductor 11B by ((λ / 4) + t + (α / 2) = L _B + t + L2)

These components are configured as the shaped beam antenna according to the present embodiment by being assembled in the following procedures (1) to (9).
(1) By inserting the coaxial cable 13 sequentially from one end P0 into the through hole 12Bh-2 of the disk conductor 12B-2, the outer conductor of the disk conductor 12B-2 is loosely fitted to the point P3 described above. .

(2) If necessary, the position of the through hole 12Bh-2 is fixed to the point P3 by caulking the disk conductor 12B-2 or soldering.
(3) By inserting the coaxial cable 13 from one end P0 into the through hole 12Bh-1 of the disk conductor 12B-1, the outer conductor of the disk conductor 12B-1 is loosely fitted to the point P2 described above.

(4) If necessary, the position of the through hole 12Bh-1 is fixed to the point P2 by caulking the disk conductor 12B-1 or soldering.
(5) The tip end portion of the central conductor of the coaxial cable 13 exposed as described above is loosely fitted (inserted) into the through hole 12Th of the disc conductor 12T, and the disc conductor 12T is caulked or soldered. By applying, the through-hole 12Th is fixed to the tip of the central conductor of the coaxial cable 13.

(6) The disk conductors 12T-1, 12B-1, and 12B-2 are integrated in this way into the hollow portion of the cylindrical conductor 11B and the coaxial cable 13 is sequentially inserted, whereby the disk conductor 12B-1 , 12B-2 are located at the aforementioned points X1 and X2, respectively, as shown in FIG.

(7) While maintaining such a state, by caulking the portions corresponding to these points X1 and X2 in the outer surface of the cylindrical conductor 11B from the outside to the inner direction, the hollow portion of the cylindrical conductor 11B The positions of the disk conductors 12B-1 and 12B-2 are fixed.

(8) By sequentially inserting the disc conductor 12T and the central conductor of the coaxial cable 13 connected to the hollow portion of the cylindrical conductor 11T, the disc conductor 12T is positioned at the point X0 described above. .

(9) While maintaining such a state, a disk conductor in the hollow portion of the cylindrical conductor 11T is formed by caulking a portion corresponding to the point X0 in the outer surface of the cylindrical conductor 11T from the outside to the inside. The position of 12T is fixed.

  Hereinafter, the principle and effect of this embodiment will be described on the premise that the cylindrical conductors 11T and 12T are arranged in a state of being continuous in the longitudinal direction.

  In the present embodiment, the feature of the present invention is that the length difference α between the cylindrical conductors 11T and 11B that respectively function as antenna elements, the position of the feeding point of these cylindrical conductors 11T and 11B, and the distance between them. In combination with the width (= d) of the space to be secured, the direction and width of the main lobe are set as follows in accordance with impedance matching with the coaxial cable 13 as described later under the combination. In the point.

  In the present embodiment, the cylindrical conductors 11T and 11B each have a length of about (λ / 2), and power is fed to the feeding point close to the space secured between them via the coaxial cable 13. Thus, it functions as a dipole antenna whose overall length is approximately one wavelength (= λ).

(Impedance matching)
In the present embodiment, the positions of the points X0 (P0) and X1 (P1) are determined based on the specifications of the coaxial cable 13 (the relative dielectric constant of the insulator, the size and shape of the central conductor, etc.) and the cylindrical conductors 11T and 11B. The absolute value of the difference between the following phase shift amounts Φ _T and Φ _B determined by the cross section and the shape and size of the hollow portion is preset to a value that becomes π radians. Such setting may be performed, for example, by finely adjusting the design parameters after the feasibility is confirmed by using an electromagnetic field simulator or the like.

(1) As shown by a thick dashed line in FIG. 1, the central conductor of the coaxial cable 13 in the section from the point P1 to the point P0 through the section S1, and the inner walls of the disk conductor 12 and the cylindrical conductor 11T from the point P0. The phase shift amount Φ _T in the section reaching the edge of the opening _AT described above

(2) As shown by a thick chain double-dashed line in Figure 1, the opening A from the outer conductor described above through the inner wall of the disc conductor 12B-1 and the cylindrical conductor 11B of the coaxial cable 13 in the vicinity of the point P1 _B Phase shift amount Φ _{B in the} section to the edge of

  That is, although the cylindrical conductors 11T and 12T are different in length, they are fed with good impedance matching with the coaxial cable 13 and function as a dipole antenna having almost one wavelength.

  Further, these cylindrical conductors 11T and 12T are arranged on a common axis in the vertical direction at a predetermined interval and are fed in parallel via the coaxial cable 13.

  Therefore, the dipole antenna according to the present embodiment does not have a narrow band like a collinear antenna in which a plurality of elements are fed in series, and the ratio band where the VSWR is “2.0” or less is 18%, which is shown in FIG. As shown in FIG. 2, a broadband characteristic is realized.

[Direction of main lobe]
The main lobe of the dipole antenna according to this embodiment is formed as a vector sum of electromagnetic fields radiated from the cylindrical conductors 11T and 12T in respective directions. Therefore, the direction of the main lobe is biased with respect to the horizontal direction if there is a difference (= | α |) between the lengths L _T and L _B of the cylindrical conductors 11T and 12T that are antenna elements. Such a difference is generally a major factor that determines the maximum value of the radiation angle in the vertical direction.

  In the present embodiment, as shown in FIG. 3, the value of α is such that the desired elevation angle at which the main lobe is to be formed (for example, the width d of the space secured between the cylindrical conductors 11T and 11B is “0”). .55λ "and when the feeding to these cylindrical conductors 11T and 11B is performed with a phase difference of 9 °, the airplane according to the present embodiment enters the runway installed in the vicinity of In this case, a suitable wireless transmission path is formed at 3 °), and the depression angle is preset to a value that can be achieved.

  Therefore, according to the present embodiment, the main lobe is accurately and stably formed in a desired direction over a wide band under the impedance matching, although the configuration is significantly simpler than that of a collinear antenna or the like. Is done.

[Width of main lobe]
The dipole antenna according to the present embodiment, the width in the vertical direction of the main lobe, a cylindrical conductor 11T is an antenna element, the distance in the vertical direction of 12T (distance between the aforementioned opening A _T and the opening A _B d) The wider it is, the narrower it becomes.

  Therefore, the distance d is set to a value at which the width of the main lobe becomes a desired value (for example, 45 °).

[Integration of Super Top]
In the present embodiment, the outer conductor of the coaxial cable 13 is connected to the disk conductor 12B-2 on the inner wall of the above-described through hole 12Bh-2, and is connected to the outer wall of the disk conductor 12B-2. The inner wall of the cylindrical conductor 11B connected to the outer wall of the disk conductor 12B-2 is separated by about a half wavelength (= (((λ / 2) + α) / 2)) as described above. opening of the cylindrical conductor 11B (opposite to the opening a _B described above.) is released at the edges.

  Therefore, the disk conductor 12B-2 and the portion of the inner wall of the cylindrical conductor 11B function as a super top connected to the outer conductor of the coaxial cable 13, and the outer conductor of the coaxial cable 13 has a high frequency. It prevents current from being carried and electromagnetic waves from being emitted from the corresponding external conductor.

  As described above, according to the present embodiment, the above-described broadening of the band and the setting of the desired direction and width of the main lobe have the following values related to impedance matching with the coaxial cable 13 as described above. Both are achieved by setting as a combination of suitable values.

(1) Difference α between the lengths L _T and L _B of the cylindrical conductors 11T and 11B
(2) Distance d
(3) Thickness of disk conductors 12T and 12B (≒ t)
(4) The thickness of the central conductor of the coaxial cable 13, the relative permittivity, shape, and dimensions of the insulator

  Furthermore, according to the dipole antenna according to the present embodiment, the structure is simple in spite of the fact that the overall length is significantly shorter than one wavelength compared to a collinear array antenna or the like, and thus it is possible to reduce the weight and the cost. Reliability is improved.

  In addition, in this embodiment, since the half-value width of directivity in the vertical direction can be narrowed compared to a half-wave dipole or λ / 4 monopole antenna, reflected waves coming from the ground direction are suppressed while maintaining a high gain. High transmission quality and communication quality can be obtained.

  The dipole antenna according to the present embodiment is configured as a combination of the above-described cylindrical conductors 11T and 11B, disk conductors 12T, 12B-1 and 12B-2, and the coaxial cable 13.

  However, the present embodiment is not limited to such a combination of only components, and the above-described operational effects are not reduced or allowed to be reduced under various constraints such as cost, manufacturing, reliability, and the like. For example, as described below, a part or all of the cylindrical conductors 11T and 11B, the disk conductors 12T, 12B-1, and 12B-2 and the coaxial cable 13 are in any form. It may be configured to be merged or divided into a plurality of elements.

(1) cylindrical conductor 11T is two connectable by engagement or screwing or the like at point X0 member (hereinafter, the one member having an opening A _T is referred to as "cylindrical conductor 11T _L", the rest of the member referred to as "cylindrical conductor 11T _U".) is configured as a disk conductor 12T these cylindrical conductor _11T L, one or fitting to both 11T _U (screwed, engagement, fitted, fitted It may be a fitting, clamping, fitting, crimping, screwing, welding, filling, fitting, press-fitting, crushing, etc.).

(2) The cylindrical conductor 11T is configured as two members (the aforementioned “cylindrical conductor 11T _L ” and “cylindrical conductor 11T _U ”) that can be connected by engagement, screwing, or the like at the point X0. The conductor 12T is integrated with one of the top of the cylindrical conductor 11T _L and the bottom of the cylindrical conductor 11T _U.

(3) three possible connection both or either one by engagement or screwing or the like between the cylindrical conductor 11B is the point X1 and the point X2 or two members (hereinafter, among these members, the opening A _B One of the near members is referred to as “cylindrical conductor 11B _U ” and the nearest member to be connected to this is referred to as “cylindrical conductor 11B _L ”), and the disk conductor 12B-1 (12B-2) is formed. these cylindrical conductor _11B U, one or both the fitting (screwed in 11B _L, engagement, fitted, fitted, clipping, fitting, crimping, screwing, welding, Hamachaku, fitted, It may be press-fitting, crushing, etc.) It is configured as a possible member.

(4) three possible connection both or either one by engagement or screwing or the like between the cylindrical conductor 11B is the point X1 and the point X2 or two members (hereinafter, among these members, the opening A _B Each of the near one member and the nearest member to be connected to it is configured as “cylindrical conductor 11B _U ” and “cylindrical conductor 11B _L ” as described above, and the disk conductor 12B. -1 (12B-2) is constructed is integrated into one of the bottom of the top portion and the cylindrical conductor 11T _U cylindrical conductor 11B _L.

  The procedure for assembling the dipole antenna according to the present embodiment is not limited to the procedure described above, and in particular, the processing applied to the coaxial cable 13, the coaxial cable 13 and the cylindrical conductors 11T and 11B, and the disk conductor 12T. , 12B-1, 12B-2, the electrical connection and alignment procedures are such that the cylindrical conductors 11T, 11B, the disk conductors 12T, 12B-1, 12B-2 and the coaxial cable 13 are of any element. Even when configured as a combination, they may be performed in an order suitable for the combination, or may be omitted as appropriate.

  Further, in the present embodiment, the disk conductor 12B-2 and the section reaching the opening at the bottom of the inner wall of the cylindrical conductor 11B connected to the outer side of the disk conductor 12B-2 are described above. It functions as a pel top.

However, in the present embodiment, when a wireless device that satisfies all of the following requirements is provided, the super conductor function is unnecessary, and therefore the disk conductor 12B-2 may not be provided.
(1) It is arranged in place of the coaxial cable 13 inside the cylindrical conductor 11B corresponding to the point X1.

(2) Transmitting and / or receiving a radio signal having a frequency f (= C / λ) having a wavelength of λ.
(3) Operates independently without linking to the outside, and links to the outside through either the wireless transmission path or the optical transmission path.

(4) The dipole antenna according to the present embodiment is applied as an antenna element used for transmission and reception.
(5) The power supply to such a dipole antenna is a balanced power supply that is directly connected to the above-described wireless device and that is derived from lines and terminals that replace the central conductor and external conductor of the coaxial cable 13 exposed by the processing described above. This is done as an unbalanced feed.

  In the present embodiment, the cylindrical conductor 11T is not configured as a cylindrical body in the section from the top to the point X0 unless the function or performance as an antenna element is hindered. You may comprise as a rod-shaped body which does not have.

  Furthermore, in this embodiment, the cylindrical conductors 11T and 11B are arranged in a state where both axes are on a virtual straight line.

  However, the present invention is not limited to such a configuration, and if the cylindrical conductors 11T and 11B are in a state where they are physically separated, the virtual extension lines of both axes are parallel, or You may arrange | position in the state which mutually cross | intersects.

  Further, in the present embodiment, the structure of the disk conductor 12B-1 (including the through hole 12Bh-1) in the vicinity of the point P1, and the processing to be performed on the jacket of the coaxial cable 13, the outer conductor, and the insulator. Is not limited to that shown in FIG. 1 (a), and may be any form listed below.

(1) As shown in FIG. 1 (b), the through-hole 12Bh-1 is formed as a hole that gradually decreases in diameter from the bottom side of the disk conductor 12B-1 and is insulated from the coaxial cable 13. The body is shaped in a shape that loosely fits (may be abutting or fitting) on the inner wall of the through hole 12Bh-1.

(2) As shown in FIG. 1 (c), the through-hole 12Bh-1 is formed in a shape and a size to be inserted (loosely fitted) into the outer conductor of the coaxial cable 13, and the outer conductor of the coaxial cable 13 is a circle. The plate conductor 12B-1 is shaped in a shape and size that does not remain above the opening of the through hole 12Bh-1 at the top.

  Further, in the present embodiment, as shown in FIG. 1, cylindrical members 11T and 11B, disk conductors 12T, 12B-1 and 12B-2 and coaxial cables 13 which are individual members (components) are combined. And it is comprised by assembling as stated above.

However, the present invention is not limited to such a configuration, and may be configured as a printed circuit as listed below.
(1) The following printed circuit formed on the inner layer (second layer) of a three-layer board

(1-1) A linear printed circuit Cc corresponding to the central conductor of the coaxial cable 13 disposed inside the cylindrical conductor 11b
(1-2) Plate-like printed circuits Ce-1 and Ce-2 that are individually formed in parallel on the two side ends of the printed circuit Cc and correspond to the outer conductor of the coaxial cable 13.

(2) A coaxial connector connected to the printed circuit Cc and the pair of printed circuits Ce-1 and Ce-2 by soldering or the like and used for connection to the antenna terminal of the above-described wireless device

(3) The first and second layers, which are the outer layers of the three-layer substrate, are individually formed and connected to each other through through holes at predetermined intervals and positions, and the layers are parallel to each other. Plate-like printed circuits C _T -1 and C _T -2 which are formed as a pair of conductor plates facing each other and substitute for the inner and outer walls of the cylindrical conductor 11T.

(4) It is formed separately on the first layer and the second layer of the same three-layer substrate, and is connected to each other through through holes at predetermined intervals and positions, and these layers are opposed to each other in parallel. Plate-like printed circuits C _B -1, C _B -2 that are formed as a pair of conductive plates that replace the inner and outer walls of the cylindrical conductor 11B.

The plate-like printed circuits C _T -1 and C _T -2 and the printed circuits C _B -1 and C _B -2 do not have any one of the first layer and the third layer described above. When a double-sided board is applied instead of the three-layer board, it may be configured as a single printed circuit.

[Second Embodiment]
FIG. 4 is a diagram showing a second embodiment of the present invention.
In this embodiment, in addition to the dipole antenna 21 according to the first embodiment described above, the reflection is a conductor plate such as a paraboloid parallel to the side surfaces of the cylindrical conductors 11T and 11B which are antenna elements of the dipole antenna 21. The device 22 is configured by being provided. Further, the reflector 22 is disposed and supported at a position separated from the cylindrical conductors 11T and 11B by about (λ / 4). The position, shape, and dimensions of the reflecting surface of the reflector 22 may be any as long as desired beam formation is realized.

  In the antenna having such a configuration, the reflector 22 has a desired opening angle (for example, 180 °, 90 °, 30 °, 0 °), as shown in FIGS. 5 and 6, the width of the main lobe in the horizontal direction of the dipole antenna 21 is narrowed down to a wide range of about 90 ° to 250 °.

  Note that the reflector 22 does not necessarily have to be configured as a conductor plate such as the paraboloid described above. For example, as illustrated in FIG. 4D, the reflector 22 may be configured as a rod-shaped body. The width of the main lobe in the horizontal direction of the dipole antenna 21 can be reduced, and the gain of the dipole antenna 21 can be set to a desired value.

[Third embodiment]
FIG. 7 is a diagram showing a third embodiment of the present invention.
In the figure, components having the same functions as those shown in FIG. 4 are given the same reference numerals, and description thereof is omitted here.
The difference between the present embodiment and the second embodiment described above is that a rod-shaped conductor (hereinafter referred to as a “rod body”) supported in parallel with the side portions of the cylindrical conductors 11T and 11B that are antenna elements. .)) At the point where the reflector 22 is configured.

  In the antenna having such a configuration, the opening angle of the reflector 22 is set in substantially the same manner as in the second embodiment, so that the main antenna in the horizontal direction of the dipole antenna 21 is set as shown in FIGS. The lobe width is narrowed to a wide range of values ranging from about 100 ° to 250 °.

  Further, in the present embodiment, as shown by a dotted line in FIG. 7, all of the opening angles that can be set in the reflector 22 and the density of the grating on which the reflector 22 is to be configured can be applied. When the support members 31T and 31B capable of supporting the rods are provided in advance as non-conductors at the power positions, the number, arrangement, and density of the rods to be supported by these support members 31T and 31B can be set. Changes can be made freely in the field, and for example, reflected waves and diffracted waves that actually arrive from buildings in an airport can be flexibly suppressed or reduced.

  Furthermore, in the present embodiment, the reflector 22 is configured as a grating, so that the physical strength against significant strong winds such as typhoons can be increased, and the characteristics of the antenna band, directivity, impedance matching, etc. can be stably maintained. It becomes possible.

  In the present embodiment, the physical strength against the strong wind is ensured by arranging the support members 31T and 31B on the inner wall or the outer wall of the radome on which the cylindrical conductors 11T and 11B are supported. May be.

Further, in the present embodiment, the reflector 22 is configured as a combination of the support members 31T and 31B having simple shapes and configurations and the rods described above, so that standardization of the components is easily realized, and manufacturing and acquisition are possible. Either of these becomes easy.
Therefore, in the wireless transmission path formed via the antenna according to the present embodiment, desired transmission quality and communication quality can be enhanced inexpensively, stably and flexibly.

  In each of the above-described embodiments, the coaxial cable 13 also serves as a structure that physically supports the dipole antenna according to this embodiment. However, such support may be realized separately by a member other than the cable 13. .

  Moreover, in each embodiment mentioned above, the shape of the cross section in the direction perpendicular | vertical to the axis | shaft of the disk conductors 12T and 12B-1 may not be circular, and the cross section of the inner wall of the coaxial cable 13 and the cylindrical conductors 11T and 11B. Any shape suitable for the shape may be used.

  Further, the present invention is not limited to an air traffic control radio system in which a main lobe should be formed in the direction in which an aircraft entering the runway is located. For example, the real number α described above is set to a negative number. Wireless that constitutes a mobile communication system such as a mobile phone in which severe restrictions are imposed on power consumption and other running costs and stationing conditions by setting the direction in which the main lobe tilts downward on the vertical plane You may employ | adopt as an antenna for base stations.

  Further, the present invention is not limited to the frequency band of the above-described air traffic control radio system or mobile communication system, and hinders the realization of the above-described configuration and the achievement of suitable operational effects under the configuration. If not, the present invention can be similarly applied to a radio system employing any frequency band, band, modulation method, and multiple access method.

  Further, the tilt angle in the vertical direction in which the main lobe is to be formed is not limited to the aforementioned 3 °, and may be set to any value, or the real number α is set to almost “0”, It may be set to 0 °.

  Further, the present invention is not limited to the above-described embodiments, and various configurations of the embodiments are possible within the scope of the present invention, and any improvements may be made to all or some of the components.

11T, 11B Cylindrical conductor 12T, 12B Disc conductor 13 Coaxial cable 21 Dipole antenna 22 Reflector 31T, 31B Support member

Claims (5)

A first antenna element having a length equal to the sum of the half wavelength (λ / 2) and the real number α ((−λ / 2) <α <(λ / 2));
A second antenna element having a length equal to the difference between the half wavelength (λ / 2) and the real number α,
The first antenna element is
A feeding line provided for feeding the first antenna element and the second antenna element is gently or loosely inserted, and a predetermined portion of the inner wall is configured as a cylindrical body serving as a first feeding point,
The second antenna element is
A shaped beam antenna formed in a longitudinal direction and having a hole or a communication hole serving as a second feeding point that is paired with the first feeding point at a predetermined portion of the bottom or inner wall. A first antenna element having a length equal to the sum of the half wavelength (λ / 2) and the real number α ((−λ / 2) <α <(λ / 2));
A second antenna element having a length equal to the difference between the half wavelength (λ / 2) and the real number α,
The first antenna element is
The first antenna terminal of the device that is arranged inside and that transmits or receives the radio signal of the wavelength λ is configured as a cylindrical body that is connected to a predetermined portion of the inner wall of the inside as a first feeding point. ,
The second antenna element is
A hole or a communication hole connected to the second antenna terminal of the device is formed as a second feeding point that is formed in the longitudinal direction and a predetermined portion of the bottom or inner wall is paired with the first feeding point A shaped beam antenna characterized by that. The shaped beam antenna according to claim 1,
The first feeding point and the second feeding point are:
A shaped beam antenna, which is set at a location where impedance matching is achieved between the feeder line, the first antenna element, and the second antenna element. The shaped beam antenna according to claim 2,
The first feeding point and the second feeding point are:
A shaped beam antenna, wherein the first antenna terminal and the second antenna terminal of the apparatus, and the impedance matching between the first antenna element and the second antenna element are set. The shaped beam antenna according to any one of claims 1 to 4,
The first antenna element and the second antenna element are:
A shaped beam antenna, characterized in that the main lobe formed by the dipole antenna is disposed at a distance and posture at which a desired value is obtained.