JP2008160818A - Antenna radiator, and antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna which can be small-sized without deteriorating electrical characteristics. <P>SOLUTION: In an antenna 1 constituted of a wave guide 3, a radiator 10 and a reflector 20, the radiator 10 is constituted of a first radiator 11 and a second radiator 12 disposed forward and backward in a radio wave radiating direction while being spaced at a predetermined interval. The radiators 11, 12 are balanced-type radiators disposing pairs of radiation elements 11a, 11b, 12a, 12b obtained by rectangular forming thin plate-like conductive materials so that the axial lines in the longitudinal directions accord with each other and are axisymmetrical about a center axis which orthogonally intersects with the axial lines. The radiator 10 is constituted by connecting the front and rear radiation elements through a phase adjusting means. Furthermore, on plate surfaces of the radiation elements 11a, 11b constituting the rear radiator 11, a plurality of slits are opened along the longitudinal direction. Moreover, the reflector 20 is constituted by bending the plate-like conductive material so that a cross section thereof becomes approximately U-shaped. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a balanced antenna radiator and an antenna including the radiator and a reflector.

  Digital terrestrial broadcasting, which has been spreading in recent years, can receive beautiful images due to its excellent characteristics if it can receive radio waves above a certain level. In addition to the existing Yagi-Uta type antennas, there is a need for antennas that can be easily installed on the veranda or indoors, and that are small, lightweight, and have good design that does not get in the way.

As an example of such an antenna, for example, an antenna is proposed in which an insulating material and several metal foil antenna elements formed in a thin film shape with a conductive material are attached to the insulator (see, for example, Patent Document 1). ).
Japanese Utility Model Publication No. 57-185207

  However, the proposed antenna is a conventional Yagi-Uda type antenna that replaces the length and shape of each element determined by the reception wavelength with a metal foil antenna element. In order to obtain the same electrical characteristics as that of the antenna, it is necessary to make it as large as the antenna. For example, the antenna can be downsized by using only a radiator and a reflector. I couldn't.

  The present invention has been made in view of these problems, and an object of the present invention is to provide an antenna that can be miniaturized without deteriorating electrical characteristics and can be installed not only on a veranda or an antenna column but also indoors. .

In order to achieve this object, the invention according to claim 1 is a balanced antenna radiator comprising:
The radiator includes a pair of first radiating elements formed of a thin plate-like conductive material in a rectangular shape, the longitudinal axes thereof being aligned with each other, and spaced apart so as to be axially symmetric about a central axis perpendicular to the axial line. Are arranged by placing
One or a plurality of slits are formed in the plate surface of each of the first radiating elements.

In the invention according to claim 2, the balanced radiators are arranged apart from each other in the front-rear direction along the radiation direction of the radio wave, and the front and rear radiators are connected to each other via the phase adjusting means. An antenna radiator,
The radiator on the rear side has a pair of first radiating elements in which a thin plate-shaped conductive material is formed in a rectangular shape so that their longitudinal axes coincide with each other and are symmetrical about a central axis perpendicular to the axial line. It is configured by placing them apart from each other,
The radiator on the front side has a pair of second radiating elements in which a thin plate-like conductive material is formed in a rectangular shape so that the longitudinal axes thereof coincide with each other and are symmetrical with respect to a central axis orthogonal to the axial line. In addition, the radiator on the rear side is arranged so that the radiating elements are parallel to each other by matching the central axes.
The front and rear radiators connect the front and rear radiating elements positioned in the same direction across the central axis to each other via the phase adjusting means with a base portion close to the central axis as a connection point. Connected,
One or a plurality of slits are formed in each plate surface of the first radiating element constituting the rear radiator.

  According to a third aspect of the present invention, in the antenna radiator according to the second aspect, the first radiating element constituting the rear side radiator is connected to the phase adjusting means at a base portion close to the central axis. The connection point is formed at a corner located on the innermost front side among the four corners of the first radiating element.

Next, the invention described in claim 4 is characterized in that, in the antenna radiator according to claim 3, the dimension of each part of the first radiating element is set as follows.
That is, in the first radiation element, formed by forming the slit, the front narrow conductor on the front side of the slit, the rear narrow conductor on the rear side of the slit, and Among the connecting narrow conductors that connect the front narrow conductor and the rear narrow conductor on the side of the slit, the line widths of the front narrow conductor and the rear narrow conductor are: It is narrower than approximately 0.016λ1 of the wavelength λ1 of the minimum frequency of the use frequency, and is a dimension capable of connecting and holding the connection narrow conductor, and the line width of the connection narrow conductor is the wavelength λ1 of the minimum frequency of the use frequency. The dimension is narrower than about 0.1λ1, and the front narrow conductor and the rear narrow conductor of the first radiating element can be connected and held.

  Further, it is a path connecting the connection point with a specific point at a corner located on the opposite side of the connection point along the longitudinal axis of the first radiation element among the four corners of the first radiation element. The dimension of the first path formed by the straight line along the front narrow conductor is 0.2λ2 to 0.4λ2 of the wavelength λ2 of the center frequency of the operating frequency, and the specific point and the connection point The dimension of the second path formed along the inner connecting narrow conductor, the rear narrow conductor, and the outer connecting narrow conductor from the connection point is the minimum of the operating frequency. The frequency λ1 is 0.2λ1 to 0.4λ1.

  According to a fifth aspect of the present invention, there is provided the antenna radiator according to any one of the first to fourth aspects, wherein at least one of the radiating elements prevents deformation of the radiating element. Means are provided.

  On the other hand, the invention described in claim 6 is an antenna including at least a radiator and a reflector, and the radiator includes the radiator of the antenna according to any one of claims 1 to 5. Features.

  According to a seventh aspect of the present invention, in the antenna according to the sixth aspect, the reflector has a longitudinal direction parallel to the polarization direction of the radio wave and is substantially parallel to a plane orthogonal to the radio wave radiation direction. The first reflector having a rectangular shape and the long side of the first reflector are bent in the radiation direction of the radio wave so that the reflection surface becomes substantially parallel to the radiation direction of the radio wave. And a second reflector formed as described above.

  According to an eighth aspect of the present invention, in the antenna according to the seventh aspect, a signal processing circuit for processing a signal received and transmitted via the radiator, which is housed in a shielded electronic equipment box. The electronic device box is configured by using a part of the first reflector.

  The invention according to claim 9 is the antenna according to claim 8, wherein the signal processing circuit is an amplifier circuit for amplifying a received signal from the radiator. The antenna according to claim 8, wherein the signal processing circuit is a mixing circuit that mixes a reception signal from the radiator and a signal having a frequency different from that of the reception signal. .

  Furthermore, the invention according to claim 11 is the antenna according to any one of claims 6 to 10, wherein the frequency of the signal that can be transmitted and received by the radiator is in the UHF band.

  In the radiator according to claim 1, the pair of first radiating elements in which a thin plate-like conductive material is formed in a rectangular shape are arranged so that the longitudinal axes thereof coincide with each other and the central axis orthogonal to the axial line is the center. It is configured by being spaced apart so as to be axially symmetric. One or a plurality of slits are formed in the plate surface of each first radiating element.

  For this reason, as will be apparent from the experimental results to be described later, compared with the case where each radiating element is simply formed of a thin plate-shaped conductive material, the frequency characteristics on the low frequency side are improved and the radiator is made wider. be able to. Further, each radiating element can be easily manufactured by simply punching and forming a thin plate-like conductive material with a mold or the like, and thus can be realized at low cost.

  The radiator according to claim 2 is configured by arranging balanced radiators spaced apart in the front-rear direction along the radiation direction of radio waves, and connecting the front and rear radiators via phase adjusting means. Has been.

  That is, in the radiator according to claim 2, the radiator on the rear side has a pair of first radiating elements in which a thin plate-like conductive material is formed in a rectangular shape with the longitudinal axis thereof aligned with the axial line. A pair of second radiating elements in which the radiator on the front side is similarly formed in a rectangular shape with a thin plate-like conductive material formed so as to be symmetrical with respect to an orthogonal central axis. Are arranged so as to be axially symmetric with respect to a central axis orthogonal to the axial line, while matching the longitudinal axis thereof.

  And the radiator on the front side and the radiator on the rear side are arranged so that the respective radiating elements are parallel to each other by making the central axes coincide with each other. The front and rear radiating elements that are located in the same direction with the pinch in between are connected by connecting each other via a phase adjusting means with a base portion close to the central axis as a connection point.

  For this reason, according to the radiator of the second aspect, as compared with the case of the radiator according to the first aspect, which is composed of only a pair of radiating elements, the rear side radiator and the front side radiator are arranged. An antenna having the maximum directivity in the arrangement direction of the radiator can be realized.

  In the radiator according to claim 2, similarly to the first radiating element according to claim 1, one or a plurality of slits are perforated on the plate surface of the first radiating element constituting the radiator on the rear side. It is installed. Therefore, also in the radiator according to claim 2, as in the case of claim 1, the frequency on the low frequency side is lower than when the first radiating element is formed of a thin plate-like conductive material without a slit. The characteristics can be improved and the bandwidth of the radiator can be increased.

  Next, in the radiator according to claim 3, in the first radiating element constituting the radiator on the rear side, the connection point formed at the base portion close to the central axis and connected to the phase adjusting means is Of the four corners of one radiating element, it is formed at the corner located on the innermost front side.

  For this reason, when considering the path to the connection point and the outer end of the first radiating element, the slit having the plurality of different line lengths is formed by the slit formed in the first radiating element. By the plurality of paths, the frequency characteristics on the low frequency side are improved, and a radiator having excellent frequency characteristics over a wide band can be realized.

  When the first radiating element is configured in this way, as described in claim 4, the first narrow radiating conductor formed on the front side of the slit in the first radiating element, and the slit The line width of the rear narrow conductor formed on the rear side is preferably set to be smaller than approximately 0.016λ1 of the wavelength λ1 of the minimum frequency of the use frequency and set to a dimension capable of connecting and holding the connected narrow conductor. The line width of the connecting narrow conductor formed on the side of the slit in one radiating element and connecting the front narrow conductor and the rear narrow conductor is approximately the wavelength λ1 of the minimum frequency of the used frequency. It is preferable to set the dimension smaller than 0.1λ1 so that the front narrow conductor and the rear narrow conductor of the first radiating element can be connected and held.

  Further, in this case, among the four corners of the first radiating element, a path connecting the specific point at the corner located on the side opposite to the connection point along the longitudinal axis of the first radiating element and the connection point. The dimension of the first path formed by a straight line along the front narrow conductor is set from 0.2λ2 to 0.4λ2 of the wavelength λ2 of the center frequency of the used frequency, and is also specified as the connection point. The dimension of the second path formed along the connecting narrow-point conductor on the inner side, the back-side narrow-width conductor, and the outer-side narrow connecting conductor from the connection point is The wavelength λ1 of the minimum frequency may be set from 0.2λ1 to 0.4λ1.

  That is, if the dimensions of the respective parts of the first radiating element are set in this way, as is clear from the experimental results to be described later, while adjusting the characteristics of the entire radiator by the slit, the first path and the second path, Therefore, it is possible to easily and inexpensively realize a radiator having a good frequency characteristic over a wide band.

  Next, in the radiator according to claim 5, at least one of the radiating elements is provided with a deformation preventing means for preventing deformation of the radiating element. Therefore, by forming the radiating element from a thin plate-shaped conductive material, even if the radiating element alone cannot secure the strength, the radiating element can be deformed through the deformation preventing means including a reinforcing plate. Can be prevented.

  Therefore, according to the radiator of claim 5, since it is possible to prevent the radiating element from being deformed when the radiator is moved or assembled, and also to prevent deformation after assembling, the number of assembling steps can be reduced and the radiation can be reduced. The characteristics can be stabilized.

  On the other hand, the invention described in claim 6 relates to an antenna including at least a radiator and a reflector, and the radiator according to any one of claims 1 to 5 described above is used as the radiator. Is done.

  For this reason, according to the antenna of the sixth aspect, an antenna having good frequency characteristics over a wide band can be realized. In particular, if the radiator according to any one of claims 2 to 5 is used as the radiator, an antenna having a sharp directivity and a high gain can be realized.

  Next, in the antenna according to claim 7, the reflector has a rectangular shape in which the direction parallel to the polarization direction of the radio wave is the longitudinal direction and is substantially parallel to a plane orthogonal to the radio wave radiation direction. The second reflector is formed so that the reflecting surface is substantially parallel to the radio wave radiation direction by bending the first reflector of the first reflector and both long sides of the first reflector in the radio wave radiation direction. And a container.

  Therefore, according to the antenna of the seventh aspect, the size of the reflector (specifically, the size in the direction perpendicular to the polarization direction of the radio wave) is shortened without deteriorating the electrical characteristics as compared with the conventional antenna. can do.

  In addition, since the size of the reflector can be shortened in this way, it is possible to provide a highly versatile antenna that can make the entire antenna thin, can be easily handled, and can be easily and safely installed.

  According to an eighth aspect of the present invention, the antenna includes an electronic device box containing a signal processing circuit for processing a signal transmitted / received via the radiator, and the box is one of the first reflectors. It is configured using the department.

  Therefore, according to the antenna of the eighth aspect, not only can the antenna and the signal processing circuit be integrated, but also there is no need to separately provide a box for housing the signal processing circuit. Can be planned.

  The signal processing circuit housed in the electronic device box is an amplification circuit that amplifies the received signal from the radiator as described in claim 9, or a radiator circuit as described in claim 10. A mixed circuit that mixes a received signal and a signal having a frequency different from that of the received signal (for example, a received signal from another antenna) can be given.

  In particular, when a mixing circuit is provided as a signal processing circuit, a single lead-in wire for drawing a received signal from the antenna to the receiving terminal side can be provided, so that the wiring work can be simplified.

  Further, the antenna of the present invention is suitable for receiving terrestrial digital broadcasting performed using the UHF band if it is configured so as to transmit and receive UHF band signals. A simple UHF antenna can be realized.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
FIG. 1 is a schematic perspective view of an antenna according to a first embodiment to which the present invention is applied as viewed obliquely from the front side in the direction of radio wave radiation, and FIG. 2 is a plan view of a radiator used for the antenna.

As shown in FIG. 1, the antenna 1 of this embodiment includes a director 3, a radiator 10, and a reflector 20.
As shown in FIGS. 1 and 2, the radiator 10 includes a first radiator 11 and a second radiator 12, and the front side of the radio wave radiation direction (in the direction of arrow F shown in FIG. 1, the direction is shown below). In this case, the second radiator 12 is arranged on the arrow F unless otherwise specified), and the first radiator 11 is arranged on the rear side with a predetermined distance from the second radiator 12. Has been.

  The first radiator 11 has a pair of first radiating elements 11a and 11b formed in a rectangular plate-shaped conductive material that is extremely thin as compared to the outer diameter shape, and is orthogonal to the axial line with its longitudinal axis line aligned. It is configured by arranging them at intervals so as to be symmetric with respect to the central axis.

  Further, the second radiator 12 has a pair of second radiating elements 12a and 12b in which a plate-shaped conductive material that is extremely thin compared to the outer diameter shape is formed in a rectangle, and the longitudinal axis thereof is aligned with the axis line. It is configured by arranging them so as to be axially symmetric with respect to an orthogonal central axis.

  The first radiator 11 and the second radiator 12 are arranged so that their central axes coincide with each other, and the first radiating elements 11a and 11b and the second radiating elements 12a and 12b are parallel to each other. Yes. In each radiator 11, 12, since the central axis is an axis along the radiation direction of the radio wave, the radio waves of each radiator 11, 12 are radiated by matching the central axis of each radiator 11, 12. The directions will also match.

  The connection point Aa formed at the inner corner closest to the central axis and at the front corner near the second radiator among the four corners of the first radiator 11a, 11b of the first radiator 11, Between Ab and the connection points Ca and Cb formed at the base (inner side) closest to the central axis in the second radiating elements 12a and 12b of the second radiator 12, the first radiator 11 and the first radiator Phase adjustment means 15a and 15b for phase adjustment are provided between the connection points Aa and Ca and the connection points Ab and Cb facing each other in the arrangement direction of the two radiators 12, respectively.

  Next, in the present embodiment, the first radiating elements 11a and 11b constituting the first radiator 11 are formed with slits 5 formed by punching with a mold or the like simultaneously with the formation of the radiators 11a and 11b. . Hereinafter, the slit 5 will be described in detail with reference to FIGS.

  FIG. 3 is a schematic view showing an example of slits formed in the plate surfaces of the first radiating elements 11a and 11b constituting the first radiator 11 of the present embodiment, and (a) shows the first radiating element. When two slits are arranged along the longitudinal direction of the element 11a, (b) shows the same arrangement of four slits, (c) shows the same arrangement of six slits, (d), ( e) and (f) show examples in which the size or arrangement of the slits is changed. FIG. 4 is a graph showing changes in the number of slits and the gain of the antenna 1 at 470 MHz.

  Further, in the following description, in order to simplify the description of the slit 5, one first radiating element 11 a constituting the first radiator 11 will be described unless otherwise specified, and the first radiating element 11 b Since the slit is formed so as to be axially symmetric with respect to the central axis, detailed description is omitted.

  As shown in FIG. 2, in this embodiment, the first radiating element 11 a on the rear side constituting the first radiator 11 is respectively formed with a slit 5 (for example, an inner slit 5 a, The intermediate slit 5b and the outer slit 5c are divided into six in the longitudinal direction of the first radiating element 11a.

  Here, using FIG. 3 and FIG. 4, paying attention to the gain at the minimum frequency (470 MHz) of the frequency used by the antenna 1 using the radiator 10 (in this embodiment, the television signal using the UHF band). The gain change between the case where the slit 5 is not formed and the case where the slit 6 is formed is experimentally confirmed for the first radiating element 11a having an outer shape of a predetermined size, and the slit 5 formed in the first radiating element 11a. The effect of will be described.

  FIG. 3 shows an example in which the slits 5 are sequentially increased from the connection point Aa side (inner side) to the distal end portion (outer side) of the first radiating element 11a with respect to the first radiating element 11a. 3 (a) shows an example in which two slits 5 are formed, in FIG. 3 (b), four slits are formed, and in FIG. 3 (c), six slits 5 are formed.

Then, under such arrangement conditions of the slits 5, the experimental result of examining the change in gain with respect to the difference in the number of slits 5 formed is a graph indicated by a solid line in FIG. 4.
According to this graph, when the first radiating element 11a has no slit 5 (slit 5 is 0), the gain of the antenna 1 is about 4 dB, and the first radiating elements 11a and 11b have two slits 5 formed. The gain of the antenna 1 is approximately 4.2 dB, and when the first radiating elements 11a and 11b are formed with four, six, and eight slits, the respective antenna gains are approximately 4.4 dB. It has been experimentally confirmed that the antenna gain is improved by about 0.4 dB by forming a predetermined number of slits 5 at predetermined positions 11a and 11b.

  As can be seen from this experimental data, the improvement of the gain by the slit 5 can be expected by providing at least four slits 5, and by providing eight slits 5 as shown in FIG. 4. And even if it has one long slit 5 which connected the some slit 5 continuously as shown in FIG.3 (d), it turns out that the effect is the same.

  Further, as shown in FIG. 3 (e), the formation position of the slit 5 is opposite to the example shown in FIGS. 3 (a), (b), and (c) in the longitudinal direction of the first radiating element 11a. When the change in the gain when arranged so as to increase in order from the outside toward the inside is examined, it shows a change as indicated by the alternate long and short dash line in the graph of FIG. 4, and FIG. As shown in FIG. 4, when the formation position of the slit 5 is increased and arranged in order from the center of the first radiating elements 11a and 11b to the outer side and the inner side in order, the change in gain is examined. 4 changes as shown by the broken line.

  That is, according to these experimental data, if a predetermined number of slits 5 having a predetermined size are disposed in a predetermined position in the first radiating elements 11a and 11b, the first radiating elements 11a and 11b are used. It can be seen that the configured radiator 10, and thus the antenna 1, can improve the gain at the minimum frequency of the used frequency band.

Although not shown in FIG. 4, the formation of the slit 5 does not affect the frequency characteristics on the wide frequency side of the operating frequency.
Here, the size of the first radiating element 11a used in the above-described experiment, the number of slits 5, the positions of the slits, and the like will be described with reference to FIGS.

  In FIG. 3A, an inner slit 5a and an outer slit 5c are formed from the connection terminal Aa side of the radiating element 11a. By forming the slit 5 in the first radiating element 11a in this way, the front narrow conductor F11a is formed on the front side of the inner slit 5a and the outer slit 5c, and the rear narrow conductor R11a is formed on the rear side. The

  The line width for connecting the inner end of the front narrow conductor F11a and the inner end of the rear narrow conductor R11a to the lower side in the figure of the innermost inner slit 5a. An inner connecting narrow conductor 6a having W6a is formed, and an intermediate portion of the front narrow conductor F11a and the rear narrow conductor R11a is connected between the adjacent inner slit 5a and outer slit 5c. An intermediate connection narrow conductor 6b having a line width W6b is formed, and the front narrow conductor F11a is interposed between the upper side in the drawing of the outer slit 5c and the tip of the first radiating element 11a. An outer connected narrow conductor 6c-1 having a line width W6c that connects the distal end side and the distal end side of the rear narrow conductor R11a is formed.

  Similarly, in FIG. 3B, the inner connection narrow conductor 6a, the three intermediate connection narrow conductors 6b, and the outer connection narrow width are formed by the inner slit 5a, the two intermediate slits 5b, and the outer slit 5c. The conductor 6c-2 is formed. In FIG. 3C, the inner connecting narrow conductor 6a and the five intermediate connecting narrow conductors 6b are formed by the inner slit 5a, the four intermediate slits 5b, and the outer slit 5c. And an outer connecting narrow conductor 6c.

Further, in FIG. 3D, one slit 5 is provided so as to be sandwiched between the inner connecting narrow conductor 6a and the outer connecting narrow conductor 6c.
In the slit examples shown in FIGS. 3A, 3B, and 3C, the line width W6a of the inner connecting narrow conductor 6a and the line width W6b of the intermediate connecting narrow conductor 6b are substantially the same line. As a result, depending on the number of slits 5 formed, the line width W6c of the outer connecting narrow conductor is different from each other as 6c-1, 6c-2, 6c, respectively. It has a width.

  In the example of FIG. 3 (e), the line width W6c of the outer connecting narrow conductor 6c and the line width W6b of the intermediate connecting narrow conductor 6b are formed to have substantially the same line width. As a result, depending on the number of slits 5 formed, the line width W6a of the inner connecting narrow conductor 6a-2 is larger than the line width W6c of the outer connecting narrow conductor 6c and the line width W6b of the intermediate connecting narrow conductor 6b. In the example of FIG. 3F, the line width W6c of the outer connection narrow conductor 6c-3 and the inner connection narrow conductor 6a-3 are larger than the line width W6b of the intermediate connection narrow conductor 6b. The line width W6a is formed wide.

Further, as shown in FIG. 5, the slits 5 are formed in the first radiating element 11a, so that at least two signal paths are formed in the first radiating element 11a.
That is, the path includes the specific point Ba at the corner located on the opposite side of the connection point Aa along the longitudinal axis of the first radiating element 11a, and the connection point Aa among the four corners of the first radiating element 11a. A first path 7 formed by a straight line along the front narrow conductor F11a, a connecting narrow conductor 6a on the inner side from the connection point Aa, a rear narrow conductor R11a, This is the second path 8 formed along the outer connecting narrow conductor 6c.

  According to the experimental data, the outer connection narrow-width conductor of FIG. 3A is used even if the radiation element has the same size and is formed in a substantially rectangular shape so as to have at least two paths as described above. If the line width W6c becomes larger than the predetermined width as in 6c-1, the effect of the slit 5 cannot be obtained, and the outer connecting narrow width as in the examples of FIGS. 3B, 3C, and 3D. It has been found that the effect of the slit 5 can be obtained if the line width W6c of the conductors 6c-2 and 6c is equal to or smaller than the predetermined dimension.

  Further, according to the experimental data, as described above, if the slit 5 is disposed at a predetermined position with a predetermined size, the slit 5 is disposed from the inside of the first radiating element 11a. Alternatively, the first radiating element 11a may be arranged inward from the tip end side, or the effect can be recognized even if the first radiating element 11a is arranged vertically from the center of the first radiating element 11a. .

  For this reason, all of the line widths W6a, W6b, and W6c of the inner connecting narrow conductor 6a, the connecting narrow conductor 6b provided in the intermediate portion, and the outer connecting narrow conductor 6c are narrower than a predetermined dimension. It can be seen that the number of the slits 5 may be one or plural.

That is, a path having an appropriate line length must be formed by forming the slit 5.
In the present embodiment, an example in which the slit 5 has a quadrangular shape is shown. However, the shape is not particularly limited as long as the width of the connected narrow conductor is equal to or smaller than a predetermined dimension as described above. Other polygonal shapes, circular shapes, elliptical shapes, and the like may be used.

From the above experimental results, it was found that the dimensions of the respective parts of the first radiating element 11a should be as follows.
That is, the line widths W6a, W6b, and W6c of the inner, middle, and outer connected narrow conductors 6 are narrower than approximately 0.1λ1 of the wavelength λ1 that is the minimum frequency of the operating frequency, and are on the front side of the first radiating element 11a. The narrow conductor F11a and the rear narrow conductor R11a are dimensioned to be connected and held.

  The dimension of the first path 7 connecting the connection point Aa and the specific point Ba is set from 0.2λ2 to 0.4λ2 of the wavelength λ2 of the center frequency of the use frequency. Similarly, the dimension of the second path 8 is The wavelength λ1 of the minimum frequency is set from 0.2λ1 to 0.4λ1.

  Further, the line width of the front narrow conductor F11a and the rear narrow conductor R11a is narrower than approximately 0.016λ1 of the wavelength λ1 of the minimum frequency of the use frequency, so that the connecting narrow conductor 6 can be connected and held. To do.

In addition, the mutual space | interval of the 1st radiator 11 and the 2nd radiator 12 should just be comprised so that it may be about 0.05 to 0.2 time of wavelength (lambda) 2 corresponding to the center frequency in a use frequency.
Here, the concrete dimension of the radiator 10 used for the said experiment is shown in FIG. FIG. 6 is an explanatory diagram showing the arrangement of each part of the antenna of this embodiment.

  In the present embodiment, the first radiator 11 includes a rectangular plate 5 having a length W11 = 150 mm and a width WW1 = 25 mm, and a substantially rectangular slit 5 having a front-rear dimension of 15 mm and a left-right dimension of 10 mm. There are six, and the wide line width of the connecting narrow conductor 6 formed thereby is 15 mm, and the line width of the front narrow conductor F11a and the rear narrow conductor R11a is 5 mm. A certain first radiating element 11a and a first radiating element 11b formed in the same configuration as the first radiating element 11a are arranged in the longitudinal direction of the first radiating element so that the length W1 of both ends is 315 mm. The axes are aligned and spaced apart so as to be axially symmetric with respect to the central axis orthogonal to the axis.

  In addition, the second radiator 12 is configured such that the second radiating elements 12a and 12b having the length W22 = 130 mm and the width WW2 = 25 mm are the longitudinal lengths of the second radiating elements 12a and 12b so that the length W2 of both ends is 275 mm. They are arranged so as to be symmetric with respect to a central axis perpendicular to the axis line, with the direction axis line being coincident.

The distance L2 between the first radiator 11 and the second radiator 12 is 60 mm.
The thus configured radiator 10 has the maximum directivity in the arrangement direction of the first radiator 11 and the second radiator 12, and has an excellent gain at a frequency on the low frequency side of the used frequency. It will have the characteristics.

  In this embodiment, each radiating element constituting the first radiator 11 and the second radiator 12 is obtained by punching a metal plate having a plate pressure t = 0.2 mm into a predetermined length. It is not limited to this embodiment as long as it is a conductive material, such as a material obtained by press-working, or a thin conductive material integrally molded with resin.

  As described above, according to the radiator 10 of the present embodiment, it has the maximum directivity in the arrangement direction from the radiator 11 on the rear side to the radiator 12 on the front side, has a sharp directivity, and is from a broadcasting station. The antenna 1 capable of receiving a transmission radio wave (UHF band TV broadcast radio wave) with high gain can be provided.

  Further, by simply punching and forming one or a plurality of slits 5 in the first radiating elements 11a and 11b constituting the radiator 11 on the rear side with a mold or the like, the frequency characteristics on the low frequency side are improved, and the antenna 1 Therefore, the broadband antenna 1 can be realized easily and at low cost.

In addition, since the first radiating elements 11a and 11b are partially lost due to the formation of the slit 5, the radiator 10, and thus the antenna 1 itself can be reduced in weight.
The antenna 1 using the radiator 10 not only has high-performance directional characteristics, but also can increase the bandwidth of signals that can be transmitted and received. Therefore, the antenna 1 is a UHF antenna that receives a television broadcast signal in the UHF band. If configured, an antenna suitable for receiving terrestrial digital broadcasting can be provided.

  By the way, since the radiation elements 11a, 11b, 12a, and 12b constituting the radiator 10 are made of a plate-shaped metal material that is extremely thin compared to the outer diameter, it may be deformed during assembly or the like. It is done.

  In this case, as a means for preventing deformation of the radiating elements 11a, 11b, 12a and 12b, as shown in FIG. 7A, the longitudinal direction of the radiating elements 11a, 11b, 12a and 12b (only 11b and 12b are shown in the figure). The ribs 42b and 41b are formed along the direction axis, and as shown in FIG. 7B, the radiating elements 11a, 11b, 12a and 12b (only 11b and 12b are shown in the drawing) are arranged in the longitudinal direction. If the bent portions 42c and 41c that are slightly bent along the axis are formed, the radiating elements 11a, 11b, 12a, and 12b are curved in the movement and assembly of the radiating elements 11a, 11b, 12a, and 12b. Therefore, deformation after assembly can be prevented, so that the number of assembling steps can be reduced and the characteristics can be stabilized.

  FIGS. 7A and 7B are side views showing examples of the deformation preventing means of the present invention. 7A and 7B, the rib 4b or the bent portion 4c is also formed on the waveguide 3 arranged on the front side of the radiator 10.

Next, the reflector 20 will be described.
As shown in FIGS. 1 and 6, the reflector 20 has a longitudinal direction parallel to the polarization direction of the radio wave (in other words, the plane of polarization), and is orthogonal to the radiation direction of the radio wave (in other words, the arrival direction). By bending the first reflector 21 having a rectangular shape arranged so as to be substantially parallel to the surface and both long sides of the first reflector 21 in the radiation direction of the radio wave (in other words, the radiator 10 side), The second reflectors 22a and 22b are formed so that the reflection surface is substantially parallel to the radiation direction of the radio wave.

  The reflector 20 is manufactured by bending a plate having a size of 320 × 100 mm into a U-shaped cross section, and in this embodiment, the dimensions of each part are set as follows.

  That is, the first reflector 21 has a length W4 = 320 mm and a height H4 = 55 mm, and the second reflector 22 has both long sides of the first radiator 21 at the bent portion 14 of the radiator 10. The width is WW4 = 22.5 mm in the direction (length is 320 mm, which is the same dimension as W4).

Further, the distance L3 between the first radiator 11 and the reflector 20 is 55 mm.
Here, the reflector 20 has a U-shaped cross section when the antenna 10 is optimized using the above-described radiator 10 and the reflector 20 made of a plate having a size of 320 × 100 mm. This is for shortening the dimension in the short direction of the reflector 20 (the dimension in the vertical direction shown in FIG. 6A) while maintaining a good frequency characteristic, so that the antenna 1 is thinned. This is the value obtained.

Hereinafter, this experiment will be described.
FIG. 8 shows data representing changes in electrical characteristics when the shape of the reflector 20 is changed.
In FIG. 8, the reflector A indicates a reflector having dimensions (W4 × H4) = 320 × 100 mm as a flat plate (that is, the second reflector 22 is flush with the first reflector 21). Thus, it is data when it is formed in a state opened on both sides (a state before being bent). (Ie, reflector A = flat plate)
The data shown by the reflector B in FIG. 8 is a flat plate similar to the reflector A, but with a height (H4) about half that of the reflector A, the dimension (W4 × H4) = 320 × 55 mm. It is data when using a vessel. (That is, reflector B = height is about half that of reflector A.)
The data indicated by the reflector C in FIG. 8 is the reflection obtained by bending the reflector 20 of this embodiment, that is, a plate material having the same dimensions (W4 × H4) = 320 × 100 mm as the reflector A into a substantially U-shaped cross section. It is data when using a container.

  The main object of the present invention is to reduce the size of the antenna without degrading the electrical characteristics. However, since the reflector is the largest of the elements constituting the antenna, the size of the reflector is reduced. Is extremely important in miniaturizing the antenna.

  As apparent from the data of the reflector A and the data of the reflector B, when the reflector is flat, the height (specifically, the length in the short direction perpendicular to the radiation surface of the radio wave) is When it becomes smaller, the gain of the antenna 1 decreases over almost the entire band.

  However, the height of the reflector B is the same as that of the reflector B. When the reflector C having a shape in which both long sides of the reflector B are bent portions 14 and the second reflector 22 is projected in the direction of the radiator 10 is used, Although the gain is slightly lower than that of the reflector A, almost the same characteristics can be obtained otherwise.

  That is, if the reflector 20 is bent in a substantially U-shaped cross section as in the present embodiment, the reflector height H4 (that is, the first reflector) is obtained without deteriorating the electrical characteristics of the antenna 1. The height of 61 can be shortened, so that the antenna 1 can be configured to be thin and slim.

  In the present embodiment, the reflector 20 is formed by bending a metal plate having a size of 320 × 110 mm and a plate pressure t = 0.2 mm, but the metal wire is formed in a mesh shape even if it is not a metal plate. The net body may be bent. Further, a film-like plate body in which a thin conductive material is integrally formed with a resin may be used. That is, the reflector 20 should just be an electroconductive material and is not limited to these.

  Further, the reflector 20 does not necessarily need to be bent and formed in a U-shaped cross section, and may be formed in a flat surface as it is, or may be formed in a substantially square shape whose upper and lower sides are inclined in the direction of the radiator. That is, the shape of the reflector 20 is not limited to these.

Next, the director 3 will be described.
As shown in FIG. 1, the director 3 is obtained by punching a thin plate-like metal material with a die or the like, similarly to the first radiating elements 11a and 11b of the radiator 10, and has a length W3 = 160. , Width WW3 = 10 mm. And it is arrange | positioned ahead of the radiator 10 at the space | interval L1 = 52mm of the radiator 12 and the waveguide 3. FIG.

This director 3 is provided for improving the high frequency characteristics of the antenna 1 and may or may not be provided as necessary.
[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS.

  9 is a schematic perspective view of the antenna of the second embodiment as viewed from the front side, FIG. 10 is a schematic perspective view of the antenna of the second embodiment as viewed from the rear side, and FIG. 11 is the second embodiment. It is the schematic sectional drawing which accommodated the antenna of a form in a cosmetic case, and cut the part.

  The configuration of the antenna 1 of the present embodiment is basically the same as that of the first embodiment. The difference from the first embodiment is that a signal for processing a reception signal output from the radiator 10 of the antenna 1. The processing circuit 30 is provided.

  The signal processing circuit 30 has a configuration in which a printed circuit board on which an amplifier circuit or the like is assembled is housed in an electronic device box (hereinafter referred to as a shield case) 31 having excellent shielding properties.

The shield case 31 is made of a conductive material such as a metal material, and includes a cylindrical frame body 32 that is open at the front and rear, and a lid body 33 that closes one opening of the frame body 32.
In the frame 32, after the printed circuit board or the like is accommodated therein, the opening on the front side is a portion that does not affect the electrical characteristics of the antenna in the first reflector 21 of the reflector 20 (in this embodiment, the reflector 20 rear side).

  Further, the opening on the rear side of the frame 32 is closed by a lid 33 made of a conductive material such as a metal material. As a result, the shield case 31 is formed by the reflector 20, the frame body 32, and the lid body 33, and the inside thereof is sealed and shielded by these respective parts.

  The signal processing circuit 30 housed in the shield case 31 may be set according to the application of the antenna 1. For example, even if the signal amplification circuit amplifies the reception signal from the antenna 1, It may be a mixing circuit that mixes the reception signal and the reception signal from the external antenna, or may be both a signal amplification circuit and a mixing circuit.

  In the present embodiment, the signal processing circuit 30 includes a signal amplification circuit and a signal mixing circuit. As shown in FIGS. 10 and 11, the shield case 31 (specifically, the frame body 32) has an external portion. An input terminal 35 for inputting a reception signal from the antenna, and an output terminal 37 for outputting a signal obtained by mixing a signal obtained by amplifying the reception signal from the antenna 1 and a reception signal input from the input terminal 35 are provided. Yes. Each of these terminals is constituted by an F-type terminal for inputting / outputting a signal via a coaxial cable.

The signal processing circuit 30 is supplied with received signals from the feed points 16 a and 16 b of the radiator 10 through the balanced line 17, the balanced / unbalanced conversion circuit 18, and the unbalanced line 19.
The reflector 20 (specifically, the first reflector 21) to which the shield case 31 is assembled is provided with an insertion hole 23 for inserting the unbalanced line 19, and the size of the insertion hole 23 is as follows. It is set so as not to affect the electrical characteristics of the antenna.

  In the present embodiment, the signal processing circuit 30 is attached to the rear side of the first reflector 21, but may be any region as long as it does not affect the electrical characteristics of the antenna 1. That is, when a part of the reflector 20 is used as a part of the shield case 31 of the signal processing circuit 30 as in this embodiment, the front of the reflector 20 is not affected unless the electrical characteristics of the antenna 1 are affected. The reflector 20 may be sandwiched between them.

Next, as shown in FIG. 11, the antenna 1 of the present embodiment is housed in a decorative case 40.
The decorative case 40 has an opening toward the upper side, and a space for housing the radiator 10 and the reflector 20 is formed on the inner side. The first radiator 11 and the second radiator are formed from the inner surface. A decorative case main body 45 having a boss for integrally mounting the radiator 12, the waveguide 3, the balance / unbalance conversion unit 18 and the like, and an opening of the decorative case main body 45 are closed. And a decorative case cover 46.

The decorative case 40 is made of a synthetic resin material or the like whose material and thickness are optimized so as not to affect the electrical characteristics of the antenna.
A boss 41 formed on the decorative case body 45 is a boss for mounting the first radiator 11 (the first radiating element 11b is shown in the figure). Thus, the first radiator 11 is fixed.

  Similarly, the second radiator 12 (the second radiating element 12b is shown in the figure) is fixed to the boss 42 with a screw 52, and the waveguide 3 is fixed to the boss 43 with a screw 53. ing.

  At this time, one end side of the phase adjusting means 15 (the phase adjusting means 15b is shown in the figure) is connected to the base portion of the second radiator 12 (connection points Ca and Cb not shown in this figure). By superposing and arranging, fixing of the second radiator 12 and one end side of the phase adjusting means 15 with the screw 52 is completed.

  Then, the other end side of the phase adjusting unit 15 is connected and fixed to the base portion of the first radiator 11 (connection points Aa and Ab not shown in this drawing) with, for example, screws 55 or the like. Installation is complete.

  Although not shown in the drawing, by providing a plurality of bosses and the like for supporting the waveguide 3 and the radiator 10 inside the decorative case body 45, the waveguide 3 and the radiator 10 can be more stably decorated. The case body 40 can be stored.

  The reflector 20 is also fixedly attached to the decorative case main body 45 by a well-known holding means (not shown). At this time, the reflector 20 attached to the reflector 20 and a part of the casing are made common. The input terminal 35 and the output terminal 37 provided in the configured signal processing circuit 30 project from the terminal portion 39 having a concentric double draining skirt formed on the bottom of the decorative case body 45 to project from the lower portion of the antenna 1. Is configured to do.

  When the antenna 1 is used outdoors, the waterproof property can be improved by attaching a waterproof boot (not shown) to the skirt portion of the terminal portion 39.

  The balance / unbalance conversion unit 18 is attached to the boss 44 formed on the decorative case main body 45 by a screw 54, and a feeding point (not shown in FIG. 11) provided at a predetermined position of the phase adjusting means 15. 16 a, 16 b) and the balance-unbalance conversion unit 18 are connected via a balanced line 17. An unbalanced line 19 is connected between the balanced and unbalanced conversion unit 18 and the signal processing circuit 30.

  In this way, the waveguide 3, the radiator 10, and the reflector 20 are arranged in parallel in a predetermined position inside the decorative case body 45, and then the decorative case body 45 is covered with the decorative case cover 46 so that the antenna is provided. 1 is completed.

  As described above, the antenna 1 of the present embodiment is small and thin, and has high-performance frequency characteristics. Therefore, as shown in FIG. 12A, the antenna mast 50, the veranda, etc. If the mast attaching means 60 for attaching the antenna 1 can be detachably fixed, it can be easily attached to the antenna mast or the like.

  Further, as shown in FIG. 12B, if a stand attachment means 49 is provided on the lower surface side of the decorative case 40 and an attachment stand 61 corresponding to the stand attachment means 49 is attached, an indoor antenna is obtained. Can also be used.

  At this time, as shown in the top view of FIG. 12B, if the stand mounting means 49 is configured so that the direction of the antenna can be freely adjusted with respect to the mounting stand 61, the reception sensitivity can be easily adjusted. So convenient.

  In addition, if the mounting stand 61 is configured to be fixed to an installation target, it can be mounted on the eaves or on the wall shown in (d) as shown in FIG. It is possible to provide an antenna having

  In addition, this invention is not limited to the said embodiment, It is also possible to change and implement the structure of each part suitably.

It is the schematic perspective view which looked at the antenna of 1st Embodiment from the diagonally forward side. It is a top view showing the structure of a radiator. It is the schematic which shows the example of the slit drilled in the plate | board surface of a 1st radiation element. It is a graph which shows the formation number of a slit, and the change of the gain in 470 MHz. It is an enlarged view of the 1st radiation element for explaining the 1st course and the 2nd course. It is explanatory drawing which shows arrangement | positioning of each part of an antenna. It is a side view which shows the structural example of a deformation | transformation prevention means. It is the data showing the change of the electrical property when changing the shape of a reflector. It is the schematic perspective view which looked at the antenna of 2nd Embodiment from the back side. It is the schematic perspective view which looked at the antenna of 2nd Embodiment from the front side. It is a schematic sectional drawing showing the state which accommodated the antenna of 2nd Embodiment in the decorative case. It is a specific use example of the antenna of the embodiment, (a) is an antenna mast, (b) is a room, (c) is an eaves bottom, and (d) is a schematic explanatory view when attached to a wall surface.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Antenna, 3 ... Waveguide, 4b, 42b, 41b ... Rib 4c, 42c, 41c ... Bending part, 5 ... Slit, 5a ... Inner slit, 5b ... Middle slit, 5c ... Outer slit, 6 ... Connection Narrow conductor, 6a ... Inner connection narrow conductor, 6b ... Intermediate connection narrow conductor, 6c ... Outer connection narrow conductor, 7 ... First path, 8 ... Second path, 10 ... Radiator, 11 ... 1st radiator, 11a, 11b ... Radiation element, F11a, F11b ... Front side narrow conductor, R11a, R11b ... Back side narrow conductor, 12 ... 2nd radiator, 12a, 12b ... Radiation element, 14 ... bent portions, 15a, 15b ... phase adjusting means, 16a, 16b ... feeding point, 17 ... balanced line, 18 ... balanced / unbalanced conversion circuit, 19 ... unbalanced line, 20 ... reflector, 21 ... first reflector 22a, 22b ... second reflector, 23 ... insertion hole, 3 ... Signal processing circuit 31 ... Shield case 32 ... Frame body 33 ... Cover body 35 ... Input terminal 37 ... Output terminal 39 ... Terminal part 40 ... Cosmetic case 41, 42, 43, 44 ... Boss 45 ... Cosmetic case body, 46 ... Cosmetic case cover, 49 ... Stand mounting means, 50 ... Antenna mast, 51, 52, 53, 54, 55 ... Screws, 60 ... Mast mounting means, 61 ... Indoor stand, Aa, Ab ... Connection point of the first radiating element, Ca, Cb, connection point of the second radiating element, Ba, Bb, symmetrical point of the first radiating element, W6a, line width of the inner connecting narrow conductor, W6b, intermediate connecting narrow width Line width of the conductor, W6c: Line width of the outer connecting narrow conductor.

Claims (11)

A balanced antenna radiator,
The radiator includes a pair of first radiating elements formed of a thin plate-like conductive material in a rectangular shape, the longitudinal axes thereof being aligned with each other, and spaced apart so as to be axially symmetric about a central axis perpendicular to the axial line. Are arranged by placing
One or more slits are perforated on the plate surface of each first radiating element, respectively. A balanced radiator is arranged to be separated in the front-rear direction along the radiation direction of the radio wave, and is a radiator of an antenna formed by connecting the front and rear radiators via phase adjusting means,
The radiator on the rear side has a pair of first radiating elements in which a thin plate-shaped conductive material is formed in a rectangular shape so that their longitudinal axes coincide with each other and are symmetrical about a central axis perpendicular to the axial line. It is configured by placing them apart from each other,
The radiator on the front side has a pair of second radiating elements in which a thin plate-like conductive material is formed in a rectangular shape so that the longitudinal axes thereof coincide with each other and are symmetrical with respect to a central axis orthogonal to the axial line. In addition, the radiator on the rear side is arranged so that the radiating elements are parallel to each other by matching the central axes.
The front and rear radiators connect the front and rear radiating elements positioned in the same direction across the central axis to each other via the phase adjusting means with a base portion close to the central axis as a connection point. Connected,
An antenna radiator, wherein one or a plurality of slits are formed on a plate surface of the first radiating element constituting the rear radiator.   In the first radiating element constituting the radiator on the rear side, the connection point connected to the phase adjusting means at the base portion near the central axis is the innermost front side among the four corners of the first radiating element. The antenna radiator according to claim 2, wherein the antenna radiator is formed at a corner located in the antenna. In the first radiating element,
The narrow front conductor on the front side of the slit, the narrow back conductor on the rear side of the slit, and the front side on the side of the slit, formed by forming the slit. Among the connecting narrow conductors that connect the narrow conductor and the rear narrow conductor,
The line widths of the front narrow conductor and the rear narrow conductor are narrower than about 0.016λ1 of the wavelength λ1 of the minimum frequency of the use frequency, and are dimensions that can connect and hold the connected narrow conductor,
The line width of the connecting narrow conductor is narrower than about 0.1λ1 of the wavelength λ1 of the minimum frequency of use, and the front narrow conductor and the rear narrow conductor of the first radiating element are connected and held. Dimensions that can be
Further, among the four corners of the first radiating element, a path connecting the connection point with a specific point at a corner located on the opposite side of the connection point along the longitudinal axis of the first radiating element. The dimension of the first path formed by a straight line along the front narrow conductor is 0.2λ2 to 0.4λ2 of the wavelength λ2 of the center frequency of the used frequency,
A path connecting the specific point and the connection point, the second path formed along the inner connecting narrow conductor, the rear narrow conductor, and the outer connecting narrow conductor from the connection point. The dimension of is 0.2λ1 to 0.4λ1 of the wavelength λ1 of the minimum frequency of the use frequency.
The antenna radiator according to claim 3.   The antenna radiator according to any one of claims 1 to 4, wherein at least one of the radiating elements is provided with a deformation preventing means for preventing deformation of the radiating element.   An antenna comprising at least a radiator and a reflector, wherein the radiator comprises the antenna radiator according to any one of claims 1 to 5. The reflector is
A first reflector having a rectangular shape arranged so that a direction parallel to the polarization direction of the radio wave is a longitudinal direction and substantially parallel to a plane orthogonal to the radio wave radiation direction;
A second reflector formed by bending both long sides of the first reflector in the radio wave radiation direction so that the reflecting surface is substantially parallel to the radio wave radiation direction;
The antenna according to claim 6, comprising: A signal processing circuit that processes a signal that is received and transmitted via the radiator, housed in an electronic device box having a shielding property,
The antenna according to claim 7, wherein the electronic device box is configured using a part of the first reflector.   The antenna according to claim 8, wherein the signal processing circuit is an amplification circuit that amplifies a reception signal from the radiator.   9. The antenna according to claim 8, wherein the signal processing circuit is a mixing circuit that mixes a reception signal from the radiator and a signal having a frequency different from that of the reception signal.   The antenna according to any one of claims 6 to 10, wherein a frequency of a signal that can be transmitted and received by the radiator is a UHF band.

Images