JP4774001B2 - Dual frequency communication antenna - Google Patents

Description

  The present invention relates to a communication antenna mainly used for PHS (Personal Handyphone System), and more particularly to a configuration of a dual-frequency shared communication antenna that can be used for two or more communication systems.

In general, as a means for ensuring a high gain in a non-directional antenna that radiates vertically polarized waves or receives vertically polarized waves, there is a technique that configures an antenna by stacking radiating elements in multiple stages in the vertical direction.
If two or more communication systems (for example, PHS using two frequencies of a 1.9 GHz band radio wave and a 2.5 GHz band radio wave) are constructed using such an antenna, communication corresponding to each frequency is performed. It is necessary to provide an antenna.
As a simple method in such a case, a method of arranging two antennas corresponding to different frequencies in a horizontal direction or a vertical direction can be considered. However, in such a method of installing two antennas side by side, it is necessary to install them by a predetermined distance or more so that each antenna interferes and the directivity characteristics are not affected. A large space is required. In addition, compared to the case of using a single antenna, an additional fitting such as a brace for installing two antennas is required, which complicates the structure of the bracket for mounting the antenna and increases the cost. Become. Furthermore, since such antennas are often installed in high places with good visibility, considering the fact that it is extremely important to adapt the antenna strength to strong winds such as typhoons, the structure of the mounting bracket It was necessary to make it very strong, and there were problems in terms of installation and cost.
There is also a method of widening a single antenna, but in order to obtain a high gain antenna, it is necessary to enlarge the shape, and there is a problem that the directivity varies depending on the frequency used. A high-performance antenna cannot be expected.
On the other hand, as in the prior art, there has been proposed an antenna that can be operated for different frequencies by the length of the stacked radiation elements and the total length of a plurality of radiation elements.
(For example, see Patent Document 1)

No. 7-5692

However, according to the conventional dual-frequency communication antenna, since the two antennas corresponding to different frequencies are arranged so that their respective axes are on the same line, the horizontal dimension does not increase. Although the installation location does not have to be large, and it has the feature that the wind receiving area of the antenna is reduced and the influence of wind etc. can be reduced, the vertical dimension is inevitably long, so it is still greatly affected by wind etc. Therefore, there remains a problem that it is necessary to strengthen the antenna mounting bracket and the like.
Therefore, in this application, it was made to solve these problems.
An object of the present invention is to provide a dual-frequency communication antenna having a simple configuration and high gain and good directivity.
Another object is to provide an inexpensive and high-performance antenna for dual-frequency communication.
Another object of the present invention is to provide an antenna for dual frequency shared communication with a simple configuration and good durability.
Another object is to provide a small and high performance antenna for dual frequency communication.
Another object is to provide a dual frequency communication antenna that may have a small installation space.
Another object is to provide a dual-frequency communication antenna having a small deviation in directivity between the two antennas.
Other purposes will become clear from the examples and data shown below.

In order to solve the above problems, the invention of claim 1 is directed to a dual frequency communication antenna that radiates vertically polarized waves or receives vertically polarized waves.
Corresponding to a first radiator corresponding to the first frequency in which the radiating elements are stacked in multiple stages in the vertical direction, and a second frequency different from the first frequency in which the radiating elements are stacked in multiple stages in the vertical direction A second radiator that is substantially parallel to each other, and is suspended at a position where the first radiator and the second radiator are within a predetermined size range, and a lower end of the first radiator Includes a first matching means and a first cable connection terminal, and a lower end of the second radiator includes a second matching means and a second cable connection terminal, and at least the first radiator. The second radiator and the first and second aligning means are housed in a single protective member formed in a cylindrical shape.

The invention of claim 2 is a dual-frequency communication antenna that radiates vertical polarization or receives vertical polarization.
Corresponding to a first radiator corresponding to the first frequency in which the radiating elements are stacked in multiple stages in the vertical direction, and a second frequency different from the first frequency in which the radiating elements are stacked in multiple stages in the vertical direction Second radiators that are substantially parallel to each other, and are suspended at positions where the first radiator and the second radiator are within a predetermined size range, and the second radiator is disposed at a lower end of the radiator. 1 radiator and second radiator matching / combining means and a cable connection terminal, and at least the first radiator, second radiator and matching / combining means are formed in a cylindrical shape. It was configured to be housed in a single protective member.

  According to a third aspect of the present invention, in the antenna for dual-frequency communication according to any one of the first or second aspects, the first radiator and the second radiator are respectively the first radiator and the second radiator. The radiating element having a length of about half the wavelength of the frequency and the second frequency is constituted by a collinear antenna formed by stacking in multiple stages.

  According to a fourth aspect of the present invention, in the dual-frequency communication antenna according to the third aspect, the radiating element is disposed outside a center conductor, a dielectric provided concentrically with the center conductor, and the dielectric. And a dielectric constant of the dielectric that constitutes each radiation element such that the lengths of the radiation element of the first radiator and the radiation element of the second radiator are substantially equal to each other. It was configured to decide.

  A fifth aspect of the invention is the dual-frequency communication antenna according to the fourth aspect of the invention, wherein the first radiator and the second radiator have a vertical position of a lowermost radiation element. It was configured to be arranged so as to be substantially equal.

  According to a sixth aspect of the invention, in the dual-frequency communication antenna according to the fifth aspect, the vertical dimension of the first radiator and the vertical dimension of the second radiator are substantially equal. It was configured as follows.

  A seventh aspect of the invention is the dual-frequency communication antenna according to any one of the third to sixth aspects, wherein the external conductor of the radiation element of the first radiator and the radiation of the second radiator are provided. The external conductor of the element is connected to a state of being electrically conductive at a predetermined position.

According to the invention of claim 1, in the dual-frequency communication antenna for radiating vertical polarization or receiving vertical polarization,
Corresponding to a first radiator corresponding to the first frequency in which the radiating elements are stacked in multiple stages in the vertical direction, and a second frequency different from the first frequency in which the radiating elements are stacked in multiple stages in the vertical direction A second radiator that is substantially parallel to each other, and is suspended at a position where the first radiator and the second radiator are within a predetermined size range, and a lower end of the first radiator Includes a first matching means and a first cable connection terminal, and a lower end of the second radiator includes a second matching means and a second cable connection terminal, and at least the first radiator. Since the second radiator and the first and second alignment means are accommodated in a single protective member formed in a cylindrical shape,
The antenna electrical characteristics corresponding to two different frequencies can be individually optimized, thereby facilitating antenna design. In addition, by arranging the two antennas close to each other so as to have an optimum dimension within a predetermined range, horizontal plane directivity disturbance due to mutual interference that occurs when the two antennas are arranged in parallel is reduced. Therefore, it is possible to provide an antenna having a small deviation in horizontal plane directivity between the two antennas.
In addition, by arranging the two antennas to be close to each other, the external dimensions (diameter) of the antenna can be reduced, and these antennas can be stored in a protective member (radome) made of one cylindrical body. Cost can be reduced.
Further, according to the invention of claim 2, it is not necessary to separately connect the cables to two different antennas, and only one cable connection terminal is required, so that the labor for connecting to the cable connection terminal is reduced. it can.

According to a third aspect of the present invention, in the dual-frequency shared communication antenna according to any one of the first or second aspects, the first radiator and the second radiator are the first radiator and the second radiator, respectively. Since the radiating element having a length of approximately half the wavelength of the frequency and the second frequency is constituted by collinear antennas stacked in multiple stages,
With a simple configuration, it is possible to provide a dual-frequency communication antenna with high gain and good directivity.

According to a fourth aspect of the present invention, in the dual-frequency shared communication antenna according to the third aspect, the radiating element is disposed on the outer side of the center conductor, the dielectric provided concentrically with the central conductor, and the outer side of the dielectric. Of the dielectrics constituting the respective radiation elements so that the lengths of the radiation elements of the first radiator and the radiation elements of the second radiator are substantially equal to each other. Since it was configured to determine the dielectric constant,
The structure of two different first and second antennas, which are stacked in multiple stages of radiation elements, is configured at the same pitch. For example, if there is one production jig, it can be used to assemble any antenna. This not only improves performance, but also reduces defective products during assembly.
Furthermore, since the components of the two antennas are composed of the same component, the types of components are reduced, so that the management of the components is facilitated and the cost can be reduced due to the mass production effect.

According to a fifth aspect of the present invention, in the dual-frequency communication antenna according to the fourth aspect, the first radiator and the second radiator are arranged in the vertical direction of the lowermost radiation element. Since it is arranged so that the positions are approximately equal,
Since the radiating elements, that is, the outer conductors, have the same dimensions optimally formed for both frequencies, they do not interfere with the electrical characteristics such as the antenna directivity, and the antenna characteristics (particularly the horizontal plane orientation). The deviation can be reduced.

According to the invention of claim 6, in the dual-frequency shared communication antenna according to claim 5, the vertical dimension of the first radiator and the vertical dimension of the second radiator are approximately. Since they are configured to be equal,
The antenna is arranged in a symmetrical position, for example, it is not necessary to make a plurality of types of cushioning parts for stably holding the antenna in the protective member (radome), and the number of types of parts can be reduced. Cost.

According to a seventh aspect of the present invention, in the dual-frequency shared communication antenna according to any one of the third to sixth aspects, the outer conductor of the radiating element of the first radiator and the second radiation. Because it is configured to be connected to the outer conductor of the radiating element of the vessel in a state of electrical continuity at a predetermined position,
Since the radiating elements, that is, the outer conductors, have the same dimensions optimally formed for both frequencies, they do not interfere with the electrical characteristics such as the antenna directivity, and the antenna characteristics (particularly the horizontal plane orientation). Therefore, it is possible to provide an antenna having a very small deviation in horizontal plane directivity between the two antennas. Further, the outer shape (diameter) of the antenna itself can be further reduced. The slim external shape can reduce the effect of the antenna on the wind, and the design of the antenna and the protective member (radome) can be simplified, thereby reducing the cost of the antenna.

Hereinafter, an example of an embodiment embodying the present invention will be described in detail with reference to the drawings.
FIG. 1 is a front view showing a first embodiment of an antenna for dual-frequency communication according to the present invention, (a) is a schematic configuration diagram, and (b) is a diagram for showing the configuration and arrangement of radiation elements. The expanded sectional view seen from the AA line shown to 1 (a) is shown, (C) is an expanded sectional view which shows the other structure and arrangement | positioning of a radiation element. FIG. 2 is a front view showing a schematic configuration of another embodiment different from the first embodiment. FIG. 3 is a front view showing a second embodiment of the antenna for dual frequency communication according to the present invention, (a) is a schematic configuration diagram, and (b) is a diagram for showing the configuration and arrangement of the radiation elements. It is the expanded sectional view seen from the BB line shown to 3 (a). 4A and 4B are front views showing a third embodiment of the dual-frequency communication antenna according to the present invention, wherein FIG. 4A is a schematic configuration diagram, and FIG. 4B is a diagram for showing the configuration and arrangement of the radiation elements. It is the expanded sectional view seen from CC line shown to 4 (a). FIG. 5 is an enlarged view of a main part showing details of the radiating element of the third embodiment, (a) shows a side view taken along line DD shown in FIG. 4 (a), and (b) shows FIG. It is sectional drawing of the radiation element seen from the EE line shown to (b). 6 and 7 show the horizontal plane directivity of the dual frequency communication antenna of the first embodiment, and FIGS. 8 and 9 show the horizontal plane directivity of the dual frequency communication antenna of the second embodiment. FIG. 11 shows the horizontal plane directivity of the antenna for dual frequency communication of the third embodiment. In the following description, when the direction is indicated, the vertical direction in the figure is the upper side and the lower side based on the antenna being in use (vertical) unless otherwise specified. The horizontal direction in the figure is the horizontal direction or the right and left sides.

(First embodiment)
An example in which the antenna for dual frequency communication according to the present invention is implemented in a collinear antenna will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a dual-frequency communication antenna, a first radiator corresponding to radio waves in the first frequency band indicated by 2, and a second frequency different from the first frequency indicated by 3. And a second radiator corresponding to radio waves in the frequency band. These are supported at the lower end so as to be arranged substantially parallel and perpendicular to each other at a predetermined distance.

  The first radiator 2 is a radiation element having a length (L1 in the figure) corresponding to approximately ½ wavelength (hereinafter, the wavelength is described as λ) of the 1.9 GHz band which is an example of the first frequency. 2a, 2b, 2c, 2d... 2m are configured in multiple stages so as to be stacked on the radiation element 2a in order from the bottom. Similarly, the second radiator 3 is a radiation element 3a, 3b, 3c, 3d... Having a length (L2 in the drawing) corresponding to approximately 1 / 2λ of the 2.5 GHz band as an example of the second frequency. 3n is configured in multiple stages so as to be stacked on the radiation element 3a in order from the bottom. The number of stages m and n of these antennas may be determined according to the gain required by the antenna, or the maximum number of stages within the length that can be accommodated if the length of the antenna is determined in the longitudinal direction. The number of stages may be the same or different.

The collinear antenna shown in this example is arranged in multiple stages so that one radiating element and the central conductor and external conductor of the radiating element located below and above it and the external conductor and central conductor are connected alternately. It is installed. This connection state is shown in FIG. 1 (a) and FIG. 1 (b). In this figure, FIG. 1 (a) is a front view showing a schematic configuration, and FIG. 1 (b) is an enlarged view for showing a connection state as viewed from the AA line shown in FIG. 1 (a). The cross section structure of the radiation element 2c which comprises the 1st radiator 2 and the cross section of the center conductor of the radiation elements 3c and 3d which comprise the 2nd radiator 3 are shown. As well shown in the figure, in the first radiator 2, a center conductor 21d protruding below the radiation element 2d located on the upper side of the outer conductor 23c of the radiation element 2c is soldered. The center conductor 21c of the radiation element 2c is connected to the lower end portion of the external conductor 23d of the radiation element 2d located on the upper side by the connection means.
Similarly, in the second radiator 3, the central conductor 31c protruding above the radiation element 3c is connected to the lower end of the external conductor 33d of the radiation element 3d located above by a known means such as soldering. The central conductor 31d protruding from the lower side of the radiating element 3d is connected to the upper end side of the outer conductor (33c) of the radiating element 3c located on the lower side. And the radiator comprised in this way is the arrangement direction of the radiation element of the 1st radiator 2 (it is connected alternately in the horizontal direction in a figure), and the radiation element of the 2nd radiator 3. The arrangement direction (alternately connected in the horizontal direction in the figure) is arranged in parallel at a position on substantially the same axis.
In addition, the example from which the arrangement state of the 1st radiator 2 and the 2nd radiator 3 differs is shown in FIG.1 (b). According to this figure, there is an example in which the arrangement direction of the radiation elements of the first radiator 2 (vertical direction in the figure) and the arrangement direction of the radiation elements of the second radiator 3 are different by 90 °. Although shown, the arrangement direction of the radiating elements is not particularly limited to the embodiment, and the distance between the first radiator 2 and the second radiator 3 is set to an optimum dimension within a predetermined range. It only has to be done.
The upper end of the radiating elements 2m and 3n may be processed at the upper end of the radiating element 2m and 3n as long as the center conductor and the outer conductor are short-circuited or left open depending on the length of the radiating element.

  Here, a specific configuration example of the radiation elements 2a..., 3a. The radiating element is composed of a central conductor 21 of the first radiator, a central conductor 31 of the second radiator, and a foamed polyethylene or polyethylene disposed concentrically on the central conductors 21 and 31, respectively. The dielectric 22 of the first radiator, which is an internal insulator, and the second radiator 32, and a thin pipe made of brass with high conductivity provided on the outer periphery of the dielectric 22 and 32. It consists of an outer conductor 23 of the first radiator and a second radiator 33. The radiation element in this embodiment is a coaxial line using a metal pipe. However, the radiation element is not particularly limited to this embodiment. For example, the radiation element may be formed using a printed wiring board. Needless to say, it may be constituted by other means.

In order to prevent unnecessary current from flowing to the outer conductor at the lower ends of the radiating element 2a and the radiating element 3a, the tips of the outer conductors of the feed lines 25 and 36 connected to the radiating element are opened. Sleeves are provided as matching circuits that are folded back by about ¼λ. The first radiator 2 has a sleeve 5 corresponding to 1.9 GHz, and the second radiator 3 corresponds to 2.5 GHz. A sleeve 6 is connected to stabilize the antenna characteristics. In the embodiment of the present invention, the sleeve is provided as the matching circuit. However, for example, the matching circuit may be configured by optimizing the line lengths of the feed lines 25 and 36. It is not limited to.
Furthermore, a low pass filter 7 (LPF) is inserted in the feed line 25 of the first radiator 2 and a high pass filter (HPF) 8 is inserted in the feed line 36 of the second radiator 3. A synthesis circuit for synthesizing the two antennas is formed after passing through the filter. A cable connection terminal 9 for connecting a coaxial cable is provided at the tip. Note that at least the sleeves 5, 6, LPF 7, and HPF 8 constitute the matching / combining means 4 described in the claims. The LPF 7 and the HPF 8 may be provided as necessary, and may be omitted if the antenna characteristics satisfy a predetermined specification.
In addition, the matching circuits such as the feeder lines 25 and 36 and the sleeves 5 and 6 may be configured using a printed wiring board in the same manner as the radiation element, and the embodiment thereof is not limited.
The configurations of the matching circuit and the synthesis circuit are the same in the second and third embodiments described in detail below.

  The first radiator 2 and the second radiator 3 are disposed substantially parallel and perpendicular to each other at a position within a predetermined dimension range (d = approximately 10 mm in the first embodiment of the present invention). So that it is supported at the lower end. These antennas are housed in, for example, a glass fiber cylinder 20 having a small dielectric loss. The aligning / synthesizing means 4 is housed in the lower end portion of the cylindrical body, and a cable connection terminal 9 is fixed to the bottom. The glass fiber cylinder 20 is the protective member according to the claims. Further, the outer periphery of the lower end portion of the cylindrical body 20 is covered with a waterproof cylinder 10 made of, for example, aluminum, and protects the alignment / synthesis means 4 and the cable connection terminal 9 from rain water that is blown or blown up by wind or the like. To do. The outer conductors of the matching / combining means 4 and the cable connection terminal 9 are electrically connected.

In the embodiment of the present invention, an example of an antenna having a matching / synthesizing means 4 and a single cable connection terminal 9 is shown. However, as shown in FIG. It goes without saying that the second radiator 3 may be configured as an independent antenna and provided with cable connection terminals 9-1 and 9-2, respectively. In this case, if each radiator is provided with a matching circuit as described above or a means corresponding to the matching circuit, a combining circuit is not required.
In these embodiments, the cable connecting terminal 9 is fixed to the lower part of the antenna. However, a coaxial cable having a predetermined length is used as the feed line, and the lower end of the coaxial cable is connected to the antenna. Needless to say, it may be provided so as to project downward, and a connection terminal may be provided at the tip of the lower end of the coaxial cable.

According to the dual frequency communication antenna configured in this way, the antenna corresponding to each of two different frequencies is configured independently, so that the electrical characteristics of the antenna are individually optimized. Antenna design. In addition, by arranging the antennas to be close to each other so that the dimensions are within a predetermined range, it is possible to reduce the disturbance of the horizontal directivity that occurs when two antennas are arranged side by side. , It is possible to provide an antenna with little variation in directivity characteristics of the two antennas.
In addition, since the antenna interval is narrow, two antennas can be accommodated in a protective member made up of one cylindrical body 20, so that the external dimensions (diameter) of the antenna can be reduced and the cost can be reduced.
FIG. 6 and FIG. 7 show the first embodiment of the present invention, which is an experiment using a dual-frequency communication antenna in which the first radiator 2 corresponds to 1.9 GHz and the second radiator 3 corresponds to 2.5 GHz. An example of the horizontal plane directivity characteristic obtained automatically is shown. FIG. 6 shows the horizontal plane directivity of the first radiator 2 (1.9 GHz), and FIG. 7 shows the horizontal plane directivity of the second radiator 3 (2.5 GHz). According to these data, even if two antennas are brought close to each other, the horizontal plane directivity deviation is good from 1.6 dB to 1.8 dB. Therefore, a suitable dual-frequency shared communication antenna for constructing two communication systems is available. It can be provided.

(Second embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. In the following description, as in the first embodiment, the first frequency is a frequency of 1.9 GHz as an example, and the second frequency band is a frequency band of 2.5 GHz as an example. An example of the case is shown.
The configuration of the antenna in the second embodiment according to the present invention is a collinear antenna as in the above embodiment, but the feature of the present embodiment is the length of the radiation element of the first radiator 2 constituting the antenna. (L1) and the length (L2) of the radiation element which comprises the 2nd radiator 3 have been comprised so that it may become substantially equal. This will be described in detail below.
As a radiation element for the 1.9 GHz band (specifically, 1902.25 MHz) which is an example of the first frequency band, for example, a dielectric whose internal insulator has a dielectric constant ε = 1.83 is used. Configure. 1 / 2λ at this frequency is 1 / 2λ = (300 / 1902.25) /2=0.0788 m from the relationship between the speed of light and the frequency. Further, since the wavelength shortening rate obtained from the dielectric constant is approximately 0.74, the length L1 of one radiation element of the first radiator 2 is L1 = 0.0788 × 1000 × 0.74 = 58. 3 mm.
In addition, a radiation element for a 2.5 GHz band (specifically, 2570 MHz) as an example of the second frequency band does not insert a dielectric so that the length of the radiation element is not shortened (that is, air becomes a dielectric). .) 1 / 2λ at this frequency is L2 = 1 / 2λ = (300/2575) /2=0.0583 m = 58.3 mm from the relationship between the speed and frequency of light, and the dimension L1 of the first radiation element is The calculated dimensions of the second radiation element L2 are substantially the same. In order to use air as a dielectric, the radiating element constituting the second radiator 3 is made of, for example, a dielectric formed at a predetermined position of the center conductor so that the dielectric loss is negligible. What is necessary is just to comprise so that it may hold | maintain in the center part of an external conductor with the holding member 16 shown by FIG.5 (b).

It should be noted that the actual dimensions of the radiating element may be optimized experimentally according to the tilt characteristics, the VSWR (voltage standing wave ratio) required for the antenna, and the characteristic characteristics such as directivity. The first radiator 2 and the third radiator 3 configured as described above are arranged in parallel and perpendicularly to positions where the optimum dimensions are within a predetermined range, respectively, so that two frequencies are shared. A communication antenna is configured.
Further, according to the second embodiment, the arrangement direction of the radiation elements of the first radiator 2 (vertical direction in FIG. 2B) and the arrangement direction of the radiation elements of the second radiator 3 (FIG. 2). Although an example in which the vertical direction in (b) is configured to be substantially parallel is shown, it is not particularly limited to the arrangement direction of the embodiment, and the first radiator 2 and the second What is necessary is just to be arrange | positioned in the position (for example, d = 10mm) from which the space | interval with the radiator 3 becomes an optimal dimension within a predetermined range.
Further, FIG. 3A of the second embodiment shows an example in which the first radiator 2 and the second radiator 3 are configured by radiation elements having the same number of stages. The number of stages may be different depending on Further, an example is shown in which the vertical positions of adjacent radiating elements, such as the radiating elements 2a and 3a positioned at the lowermost position, are opposed to each other, but the distance between the antennas is predetermined. If the optimum dimensions are within the range and the electrical characteristics are satisfied, they may be shifted in the vertical direction.

According to the dual-frequency shared communication antenna configured as described above, the effects of the first embodiment are provided, and the radiating elements constituting the two antennas, that is, the external conductors, are optimally dimensioned for both frequencies. Since it is further improved that the radiating elements interfere with each other's electrical characteristics such as the antenna directivity, the antenna characteristics (particularly the horizontal plane directivity) are not degraded. An antenna with a small horizontal plane directivity deviation can be provided.
In addition, since the radiating elements constituting the two antennas are formed so as to have the same dimensions, the configurations of two different first and second antennas formed by stacking the radiating elements in multiple stages have the same pitch. For example, if there is one production jig or the like, not only can it be used for assembling any antenna, but the productivity can be improved, and defective products in assembly can be reduced.
Furthermore, since the components of the two antennas are made of the same component, the types of components are reduced, so that the management of the components is facilitated and the cost can be reduced due to the mass production effect of the components.
FIG. 8 and FIG. 9 are experiments using the dual-frequency communication antenna according to the second embodiment of the present invention in which the first radiator 2 corresponds to 1.9 GHz and the second radiator 3 corresponds to 2.5 GHz. An example of the horizontal plane directivity characteristic obtained automatically is shown. FIG. 8 shows the horizontal plane directivity of the first radiator 2 (1.9 GHz), and FIG. 9 shows the horizontal plane directivity of the second radiator 3 (2.5 GHz). According to this data, even if two antennas are brought close to each other, the horizontal plane directivity deviation is 0.9 dB to 1 dB, which may be compared with the first embodiment, which is suitable for constructing two communication systems. An antenna for dual frequency communication can be provided.

(Third embodiment)
Next, a third embodiment of the present invention will be described. The first and second embodiments show examples in which the respective radiators are arranged so as to be suspended with an optimum dimension interval equal to or less than a predetermined range. In the third embodiment shown below, As shown well in FIGS. 4 and 5, the first radiator 2 and the second radiator 3 are brought into contact (d = 0 mm), and the predetermined positions of the outer conductors of the respective radiation elements are soldered. It connects so that it may electrically connect by the well-known means.
First, the detailed structure and assembly method of the radiation elements stacked in multiple stages will be described in detail using the third embodiment. FIG. 5 (a) is an enlarged side view of the radiating element viewed from the line DD shown in FIG. 4 (a), and FIG. 5 (b) is an EE line shown in FIG. 4 (b). It is sectional drawing which shows the structure of the radiation element in. In the following description, in order to simplify the description, attention is paid to the radiating element 2c constituting the first radiator 2, and the upper and lower radiating elements have the same configuration, and thus the description thereof is omitted. Further, the radiating elements constituting the second radiator 3 have the same configuration, and detailed description of the radiating elements constituting the second radiator 3 is omitted for the sake of simplicity.

The radiating element 2c is an internal insulator having an outer conductor 23c formed to a length corresponding to approximately ½λ of a 1.9 GHz band, which is an example of a first frequency, and an insertion hole through which the center conductor 21c is inserted at the center. It is composed of a dielectric 22c, which is a body, and a central conductor 21c formed in such a length as to project vertically.
First, the central conductor 21c is inserted through the internal insulator 22c. (Note that if there is a cable provided with a dielectric on the outer periphery of the center conductor in advance, it may be cut into a predetermined dimension and used with a predetermined dimension processed at both ends). And the assembly of the radiation element 2c is completed by inserting the inner insulator 22c provided with the center conductor 21c through the outer conductor 23c.

  The radiating element 2c and the radiating element 3c that have been assembled in this way are combined into one set, and a predetermined position between the outer conductors is connected to a connecting means 18 such as soldering (for the sake of clarity, the connecting means 18 in FIG. Is omitted). The connection position may be determined as appropriate so that the electrical characteristics of the antenna can be maintained and the connection state can be maintained against vibration and impact. The central conductors 21c and 31c projecting downward from the pair of radiation elements are connected to the upper ends of the external conductors 23b and 33b of the radiation element 2b and the radiation element 3b by connecting means such as soldering, and the radiation element 2b. The central conductor 21b protruding above the radiating element 3b and the unillustrated 31b are connected to the lower ends of the external conductors 23c and 33c of the radiating element 2c and the radiating element 3c by connecting means such as soldering. In addition, the center conductor and the outer conductor are alternately connected. Similarly, the radiation elements 2d and 3d are arranged on the upper side of the radiation elements 2c and 3c so that the center conductor and the outer conductor are alternately arranged, so that the radiation elements are stacked in multiple stages. The antenna is configured in the above.

  At this time, for example, four penetrations for inserting the central conductor are not provided between the radiating elements adjacent to each other in the vertical direction so that the outer conductors of the radiating elements positioned above and below and the central conductors positioned in the front, rear, left and right are not in contact. It is more preferable that spacers 12 having holes 12a and 12b and 12c and 12d not shown in the drawings are inserted in the respective connecting portions (FIGS. 1 to 4 show spacers in order to simplify the drawings. 12 is omitted).

Further, a buffer member 15 formed by foaming a plastic such as polyurethane having a low dielectric loss is provided at substantially the center of the radiating element (see FIGS. 1 to 4). In order to simplify the drawing, the buffer material 15 is omitted). When the antenna is stored in the radome 20, the buffer member 15 does not interfere with the antenna storage by reducing the diameter inward, and after the antenna is stored in the radome 20, the buffer member 15 should expand. The antenna is maintained at a predetermined position of the radome 20 by the urging force, and the distance between the first radiator 2 and the second radiator 3 is maintained at an optimum interval within a predetermined range. This is a positioning material. In addition, a load is applied to the radiating element and its connection part due to vibrations and shocks generated by the wind during transportation of the antenna and after installation, so that the radiating element and its connection part are damaged or deteriorated. It has a role as a cushioning material to prevent it from happening. The buffer member 15 may be provided in each of the radiating elements, or may be configured to be selectively provided at a necessary portion of the antenna.
As described above, this antenna is assembled. Needless to say, the spacer 12 and the buffer member 15 used in this embodiment may be applied to the first and second embodiments.

In the third embodiment of the present invention, the radiation element of the first radiator 2 and the radiation element of the second radiator 3 are brought into contact with each other, and further, a predetermined position between the external conductors of the radiation element is soldered. Although the configuration in which the connecting means is used to connect the predetermined positions of the outer conductors as in the third embodiment, the first radiator as in the first embodiment or the second embodiment is used. You may apply to the antenna of the structure which arranged 2 and the 2nd radiator 3 in parallel so that it might become the predetermined dimension in a predetermined range. In this case, the connecting means may be a rod or plate made of a conductive material, or may be a lead wire, tin-plated wire, or the like.
In other words, as can be seen from the above embodiment, the range within the predetermined dimension in which the first radiator 2 and the second radiator 3 are arranged in the dual-frequency shared communication antenna of the present invention is 0. (That is, the state where the two antennas are in contact with each other) is within a predetermined size range, and if the distance between the antennas is 0, the connection means can be used to obtain a very good characteristic. However, if the antennas are arranged slightly apart from each other, characteristics that are less affected by each other can be obtained regardless of whether the connection means may be connected. Depending on the cost, the distance between the antennas and the necessity of the connection means may be determined.

According to the antenna of the third embodiment, the first radiator 2 and the second radiator 3 are separated from each other by a predetermined dimension within a predetermined range as in the first and second embodiments. It was confirmed experimentally that the antenna has a smaller deviation in horizontal plane directivity than the antenna configuration. Further, since the outer dimensions of the antenna can be further reduced by bringing the outer conductors of the two radiators into contact with each other, the diameter of the antenna can be reduced. In addition, since the protective member 20 (radome) can also be made thin, the wind receiving area of the antenna is reduced accordingly, so that the structure can be simplified and the cost can be reduced. .
FIG. 10 and FIG. 11 show the third embodiment of the present invention, which is an experiment using a dual-frequency shared communication antenna in which the first radiator 2 corresponds to 1.9 GHz and the second radiator 3 corresponds to 2.5 GHz. An example of the horizontal plane directivity characteristic obtained automatically is shown. FIG. 10 shows the horizontal plane directivity of the first radiator 2 (1.9 GHz), and FIG. 11 shows the horizontal plane directivity of the second radiator 3 (2.5 GHz). According to this data, the number of man-hours for assembly for connecting external conductors is increased compared to the first and second embodiments, but the horizontal plane directivity deviation is substantially 0 dB, which is almost affected by each other's radiators. Since it is possible to obtain a very good characteristic with nothing, it is possible to provide an optimum dual-frequency shared communication antenna for constructing two communication systems that require higher performance antennas.
Note that the present invention is not limited to the above-described embodiment, and the configuration of each part can be appropriately changed and implemented without departing from the spirit of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS It is a front view which shows 1st Example of the antenna for dual frequency communication which concerns on this invention, (a) shows schematic structure, (b) is FIG. 1 (a) for showing the structure and arrangement | positioning of a radiation element. (C) is an expanded sectional view which shows the other structure and arrangement | positioning of a radiation element. It is a front view which shows schematic structure which shows the Example from which a 1st Example differs. It is a front view which shows 2nd Example of the antenna for dual frequency communication which concerns on this invention, (a) shows a schematic block diagram, (b) is FIG. 3 (a) for showing the structure and arrangement | positioning of a radiation element. It is the expanded sectional view seen from the BB line shown to). It is a front view which shows 3rd Example of the antenna for dual frequency communication which concerns on this invention, (a) shows a schematic block diagram, (b) is FIG. 4 (a) which shows the structure and arrangement | positioning of a radiation element. It is the expanded sectional view seen from the CC line shown in FIG. It is a principal part enlarged view which shows the detail of the radiation element of 3rd Example, (a) shows the side view seen from the DD line | wire shown to Fig.4 (a), (b) is FIG.4 (b). It is sectional drawing of the radiation element seen from the EE line | wire shown in FIG. The horizontal plane directivity characteristic of the 1st radiator (1st frequency = 1.9 GHz) of 1st Example is shown. The horizontal plane directivity characteristic of the 2nd radiator (2nd frequency = 2.5 GHz) of 1st Example is shown. The horizontal surface directivity characteristic of the 1st radiator (1st frequency = 1.9 GHz) of 2nd Example is shown. The horizontal directivity characteristic of the 2nd radiator (2nd frequency = 2.5 GHz) of 2nd Example is shown. The horizontal plane directivity characteristic of the 1st radiator (1st frequency = 1.9 GHz) of 3rd Example is shown. The horizontal surface directivity characteristic of the 2nd radiator (2nd frequency = 2.5 GHz) of 3rd Example is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Antenna for dual frequency communication, 2 ... 1st radiator, 2a * 2b ... 2m ... Radiation element of 1st radiator, 3 ... 2nd radiator, 3a * 3b ... 3n ... Radiating element of second radiator, 4 ... matching / synthesizing means, 5 ... sleeve of first radiator, 6 ... sleeve of second radiator, 7 ... low-pass filter (LPF), 8 ... high-pass filter (HPF) ), 9, 9-1, 9-2 ... cable connection terminal, 10 ... waterproof cylinder, 12 ... spacer, 15 ... buffer member, 16 ... holding member, 18 ... connection means, 20 ... protection member (cylinder, radome) , 21a, 21b,... 21m, the central conductor of the first radiator, 22a, 22b,... 22m, the internal insulator (dielectric material) of the first radiator, 23a, 23b,. The outer conductor of the radiator, 25... The first radiator feed line, 31a 31b ... 31n ... center conductor of the second radiator, 32a, 32b ... 32n ... internal insulator (dielectric) of the second radiator, 33a, 33b ... 33n ... second radiator The outer conductor of 36, ... the feed line of the second radiator.

Claims (7)

In a dual frequency communication antenna that radiates vertically polarized waves or receives vertically polarized waves,
Corresponding to a first radiator corresponding to the first frequency in which the radiating elements are stacked in multiple stages in the vertical direction, and a second frequency different from the first frequency in which the radiating elements are stacked in multiple stages in the vertical direction A second radiator that is substantially parallel to each other, and is suspended at a position where the first radiator and the second radiator are within a predetermined size range, and a lower end of the first radiator Includes a first matching means and a first cable connection terminal, and a lower end of the second radiator includes a second matching means and a second cable connection terminal, and at least the first radiator. The dual-frequency communication antenna, wherein the second radiator and the first and second matching means are housed in one cylindrical protective member. In a dual frequency communication antenna that radiates vertically polarized waves or receives vertically polarized waves,
Corresponding to a first radiator corresponding to the first frequency in which the radiating elements are stacked in multiple stages in the vertical direction, and a second frequency different from the first frequency in which the radiating elements are stacked in multiple stages in the vertical direction Second radiators that are substantially parallel to each other, and are suspended at positions where the first radiator and the second radiator are within a predetermined size range, and the lower end of the radiator is A first radiator and a second radiator matching / combining means and a cable connection terminal are provided, and at least the first radiator, the second radiator and the matching / combining means are formed in a cylindrical shape. An antenna for dual frequency communication, which is housed in a single protective member.   The first radiator and the second radiator are each composed of a collinear antenna in which radiation elements having a length of approximately half the wavelength of the first frequency and the second frequency are stacked in multiple stages. The dual-frequency communication antenna according to any one of claims 1 and 2, wherein the antenna is for dual-frequency communication.   The radiation element includes a central conductor, a dielectric provided concentrically with the central conductor, and an external conductor disposed outside the dielectric, and the radiation element of the first radiator and the first conductor The dual-frequency communication antenna according to claim 3, wherein the dielectric constant of the dielectric constituting each radiation element is determined so that the lengths of the radiation elements of the two radiators are substantially equal.   The said 1st radiator and said 2nd radiator are arrange | positioned so that the position of the up-down direction of the radiation element located in the lowest side may become substantially equal. Dual frequency communication antenna.   6. The dual frequency communication antenna according to claim 5, wherein a vertical dimension of the first radiator and a vertical dimension of the second radiator are substantially equal. .   The outer conductor of the radiating element of the first radiator and the outer conductor of the radiating element of the second radiator are connected in an electrically conductive state at a predetermined position. Item 7. The dual-frequency shared communication antenna according to any one of items 6.

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