JP2008048014A - Antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a thin antenna having good characteristics. <P>SOLUTION: In an antenna having at least a radiator and a planar reflector, the reflector consists of a first reflector formed in rectangle having the longitudinal direction parallel with the polarization direction of received radio wave, and arranged substantially in parallel with a plane intersecting the incoming direction of radio wave perpendicularly; and a second reflector formed in rectangle by bending the opposite long sides of the first reflector at the bends in the direction of the radiator to have the longitudinal direction parallel with the polarization direction of received radio wave, and arranged substantially in parallel with the incoming direction of radio wave. The antenna has a circuit for processing a received signal contained in the housing of electronic apparatus exhibiting shield performance wherein the housing of electronic apparatus is constituted by utilizing a portion of the first reflector. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to an antenna mainly used for television reception, and more particularly to an antenna configuration suitable for a UHF antenna that receives television radio waves in the UHF band.

Digital terrestrial broadcasting, which has been spreading in recent years, can receive beautiful images due to its superior 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.
(For example, see Patent Document 1)

Japanese Utility Model Publication No. 57-185207

However, the antenna shown in the past is the one in which the length and shape of each element determined by the reception wavelength is replaced with a metal foil antenna element, like a general Yagi-Uda type antenna, in order to obtain desired characteristics. For example, if the antenna is made up of only a reflector and a radiator, and the antenna is miniaturized, and the antenna is easy to attach to a veranda or antenna post, the electrical In order to obtain the same electrical characteristics as those of an antenna using a conventional elongated conductor rod, the outer shape of the antenna remains the same size. Furthermore, since the antenna is composed of a metal foil antenna element formed on an insulating material, the antenna can be made thin. However, as is often seen in Yagi-Uda type antennas, a metal wave antenna element that constitutes a reflector. In order to further improve the characteristics by increasing the number of stages, there is a problem that the configuration of the antenna becomes complicated and the cost increases.
Therefore, in the present invention, by reducing the size of the antenna and making it as thin as possible, it is possible to propose a highly versatile antenna that has good operability for indoor installation as well as a veranda and antenna support. Is,
The purpose is to propose an antenna with a simple structure and good electrical characteristics.
Another object is to propose an antenna having good characteristics over a wide band.
Another object is to provide a small but high-performance antenna.
Another object is to provide a simple and safe antenna for installation work.

In order to solve the above problems, the invention of claim 1 is an antenna including at least a radiator and a flat reflector,
The reflector has a longitudinal direction in a direction parallel to a polarization direction of a received radio wave, and a first reflection formed in a rectangular shape arranged substantially parallel to a plane orthogonal to the arrival direction of the radio wave. The first and second long sides of the first reflector are bent at the bent portions in the direction of the radiator, and have a longitudinal direction parallel to the direction of polarization of the received radio wave. And a second reflector formed in a rectangular shape arranged substantially in parallel with a plane parallel to the direction of arrival.

According to a second aspect of the present invention, in the antenna according to the first aspect, the antenna includes a signal processing circuit that processes a received signal accommodated in an electronic device box having a shielding property, and the electronic device box includes: A part of the first reflector is used.

According to a third aspect of the present invention, in the antenna according to the second aspect, the signal processing circuit is configured to be an amplifier circuit that amplifies a signal received by the antenna.

According to a fourth aspect of the present invention, in the antenna according to the second aspect, the signal processing circuit is an external circuit that receives a frequency band different from a signal received by the antenna and a frequency band signal received by the antenna. It is configured to be a mixing circuit that mixes the signal received by the antenna.

According to a fifth aspect of the present invention, in the antenna according to any one of the first to fourth aspects, the frequency used is in the UHF band.

According to the first aspect of the present invention, the rectangular shape has a longitudinal direction in a direction parallel to the direction of polarization of the radio wave received by the reflector, and is arranged substantially parallel to a plane orthogonal to the arrival direction of the radio wave. The formed first reflector and both long sides of the first reflector are bent at the bent portion in the direction of the radiator, respectively, in a direction parallel to the polarization direction of the received radio wave. Since it is configured to include a second reflector formed in a rectangular shape having a longitudinal direction and substantially parallel to a plane parallel to the arrival direction of radio waves, the vertical dimension of the reflector is increased. And a thin antenna can be provided. In addition, even if the reflector is thin, a small antenna with a simple structure and good electrical characteristics can be obtained because it has substantially the same characteristics as the electrical characteristics of a large flat reflector. Therefore, it is possible to provide a highly versatile antenna that is easy to handle and can be installed easily and safely.

When an amplifier circuit for amplifying a signal received by an antenna or a mixing circuit for mixing a signal received by an external antenna different from the antenna is provided as described in claims 2 to 4 Since it is configured to be accommodated in a shielded electronic device box configured using a part of the first reflector, the reflector and the electronic device box are disposed at a position where they are overlapped. Therefore, even if the electronic device box is provided, the shape of the antenna does not increase. Furthermore, the antenna configuration is simplified and the cost can be reduced. And since the components become short, the weight of the antenna can be reduced. In addition, wiring is easy because there is only one lead-in wire from the antenna.

If the antenna is adapted to the UHF band as in the configuration shown in claim 5, a UHF antenna suitable for receiving digital terrestrial broadcasting can be provided.

Hereinafter, an example of an embodiment embodying the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic perspective view showing a configuration of a first embodiment of an antenna according to the present invention, FIG. 2 is a schematic configuration diagram of a radiator constituting the antenna of the first embodiment, and FIG. 3 is a first embodiment. It is the schematic which shows the structure of the antenna of an example, (a) is a right view, (b) is a top view. FIG. 4 is a schematic front perspective view showing the configuration of the antenna according to the second embodiment of the present invention. FIG. 5 is a rear schematic perspective view showing the configuration of the antenna of the second embodiment according to the present invention, FIG. 6 is a schematic sectional view of a part of the antenna of the second embodiment, and FIG. In the antenna of the second embodiment, the electrical characteristic data is obtained when the shape of the reflector is changed.

1 shown in the figure is an antenna according to a first embodiment of the present invention. The antenna 1 of the present invention includes at least a radiator 10 and a reflector 20.
First, the radiator 10 will be described with reference to FIGS. 1 and 2. 1 and 2, reference numeral 10 denotes a radiator according to an embodiment of the present invention. As shown in this figure, the radiator 10 includes the first radiator 11 and the second radiator 12 in the second radiator 12 in the front (in the direction of arrow F shown in the figure) and the first in the rear. The radiator 11 is configured to be spaced apart from each other in parallel. The first radiator 11 has a pair of radiating elements 11a and 11b formed of a thin plate-like conductive material in a rectangular shape and arranged in a symmetrical position with their longitudinal axes coincided with each other. The second radiator A pair of radiating elements 12a and 12b, each having a thin plate-like conductive material formed in a rectangular shape, are arranged at symmetrical positions with their longitudinal axes aligned with each other, and the first radiator 11 and the second radiator 12 Are arranged in parallel with a predetermined distance from each other.
In addition, among the four corners of the radiating elements 11a and 11b of the first radiator 11 formed in a rectangular shape, the inner portions Aa and Ab positioned on the second radiator side on the innermost side, and the second radiator 12 Phase adjustment between the base portions Ca and Cb of the radiating elements 12a and 12b and the base portion and the base portion facing each other in the arrangement direction of the first radiator 11 and the second radiator 12, respectively. Phase adjusting means 15a and 15b are provided.

Then, the length, interval, and the like of the first radiator 11 and the second radiator 12 are determined so that desired electrical characteristics can be obtained in this configuration. According to the present invention, the length of the first radiator 11 is approximately one half of the wavelength λ1 corresponding to the minimum frequency at the use frequency, and the length of the second radiator 12 is set to the center frequency at the use frequency. It is approximately half of the corresponding wavelength λ2, and the distance between the first radiator and the second radiator is approximately 0.05 to 0.2 times the wavelength λ2 corresponding to the center frequency at the operating frequency. It is configured.
Here, specific dimensions of the radiator are shown in FIG. The first radiator 11 is arranged such that radiating elements having a length W11 = 150 mm and a width WW1 = 25 mm are spaced apart from each other at symmetrical positions with the longitudinal axes thereof aligned so that the length W1 = 315 mm. The second radiator 12 is arranged such that radiating elements having a length W22 = 130 mm and a width WW2 = 25 mm are spaced apart from each other at symmetrical positions with their longitudinal axes aligned so that the length W2 = 275 mm. The distance L2 between the first radiator 11 and the second radiator 12 is 60 mm.
The radiator 10 configured as described above is configured to have the maximum directivity in the arrangement direction of the first radiator 11 and the second radiator 12.
In the embodiment of the present invention, the first radiator 11 and the second radiator 12 are formed by punching a metal plate having a plate pressure t = 0.2 mm into a predetermined length. However, the conductive material is not limited to the embodiment. For example, the conductive material may be formed by integrally molding a thin conductive material with resin.
In the embodiment of the present invention, the phase adjusting means 15 may be formed by etching a metal conductor provided on a printed wiring board to a predetermined length, or a metal plate or the like is formed by punching to a predetermined length. Or may be formed.

Since the radiating element constituting the radiator 10 is made of a thin metal material, it may be deformed during assembly or the like. In this case, ribs 4b, 42b and 41b are formed as shown in FIG. 4 (a) as means for preventing deformation of the radiating element, or the radiating element is placed on the longitudinal axis as shown in FIG. 4 (b). If the bending process 4c, 42c, 41c is slightly performed along the radiating element, the radiating element is not deformed by bending or the like during the movement or assembly of the radiating element. Reduction of man-hours and stabilization of characteristics can be achieved.

Next, the reflector 20 will be described. As shown in FIGS. 1, 3 and 4, the reflector 20 shown in the present invention has a longitudinal direction parallel to the direction of polarization of a received radio wave and is orthogonal to the arrival direction of the radio wave. The first reflector 21 formed in a rectangular shape arranged substantially parallel to the surface to be bent, and both long sides of the first reflector 21 are bent in the direction of the radiator 10 (that is, the first reflector 21). (Long side) 14 is formed in a rectangular shape having a longitudinal direction parallel to the direction of polarization of the received radio wave and substantially parallel to a plane parallel to the arrival direction of the radio wave. And second reflectors 22a and 22b.
Here, specific dimensions of the reflector 29 are shown in FIG. The first reflector 20 has a length W4 = 320 mm and a height H4 = 55 mm, and the second radiator 12 has a width WW4 = 22.5 mm (length) in the direction of the radiator 10 at the long side 14 of the first radiator. Is folded back by the same dimension as W4 (320 mm). The distance L3 between the first radiator 11 and the reflector 20 is 55 mm.
In the embodiment of the present invention, the reflector 22 is formed by bending a metal plate having a plate pressure t = 0.2 mm into a predetermined length. However, the reflector 22 may be formed by pressing a conductive material or a thin conductive layer. As long as it is a conductive material, it is not limited to the embodiment.

Next, the director 3 will be described. Like the radiating element of the radiator 10, the waveguide 3 is obtained by punching a thin plate metal material with a mold or the like, and has a length W3 = 160 and a width WW3 = 10 mm. The distance L1 between the radiator 12 and the director 3 is 52 mm. The director 3 is provided for a wide area and may or may not be provided as necessary.

Here, the effect of the reflector 20 of the antenna according to the present invention will be described with reference to FIG. The data shown in FIG. 7 shows the data change when the shape of the reflector 20 is changed. In FIG. 7, the reflector A shows a reflector size (W4 × H4) = 320 × 100 mm, in which the reflector is generally used for an antenna (that is, the second reflector 22 is the first reflector 22). This is data when it is in a state opened on both sides so as to be on the same plane as one reflector 21 (a state before being bent). (That is, reflector A = flat plate)
In FIG. 7, the reflection plate B shows the data when the plate shape is the same as that of the reflection plate A, but the height H4 is 320 × 55 mm, which is about half the dimension. (That is, reflector B = height is about half that of reflector A.)
In FIG. 7, the reflector C is the reflector 20 shown in the embodiment according to the present invention, and the reflector 20 is seen from the long side of the first reflector 21 as well shown in FIG. This is data in the case where the second reflector 22 is formed in a substantially U-shaped cross section formed by bending in the radiator direction. In this case, since the dimensions of the first reflector 21 are 320 × 55 mm and the second reflector 22 is in a state of protruding 22.5 mm in the direction of the radiator 10, the height of the reflector C is This is the same as a 100 mm reflector A bent in a U shape. (That is, reflector C = reflector A is made U-shaped.)

The main object of the present invention is to provide an antenna having good characteristics even if it is miniaturized. Among them, the reflector is the largest element among the elements constituting the antenna, so that the shape of the reflector is miniaturized. Is extremely important in reducing the antenna shape. However, as shown in FIG. 7, as can be seen from the comparison between the reflector A having a size of 320 × 100 mm and the reflector B having a height of approximately 320 × 55 mm, the reflector is small. As a result, there arises a problem that the gain decreases over almost the entire band.
Then, the second reflector 22 is projected from the long side 14 of the reflector B in the direction of the radiator 10 with the height of the reflector B as it is, and the reflector C having a substantially U-shaped cross section is used. When the electrical characteristics are measured, it can be seen that although the operating gain is slightly lower than that of the reflector A, other than that, almost the same characteristics can be obtained.
That is, by adopting the configuration shown in the reflector 20 shown in the embodiment of the present invention, the height H4 of the reflector (that is, the height of the first reflector 61) is set to a height of 100 mm. Even if it is about half of the reflector, the height dimension of the reflector can be reduced without deteriorating the electrical characteristics, and the antenna can be made thin and slim.

Next, a second embodiment of the antenna of the present invention will be described with reference to FIGS. This embodiment has the same antenna configuration as that of the first embodiment, but includes a signal processing circuit 30 that performs predetermined processing on a signal received by the antenna. Hereinafter, in order to simplify the description, the signal processing circuit 30 will be described using an example in which the signal processing circuit 30 is a signal amplification circuit for amplifying a signal received by an antenna. The signal amplifier circuit 30 has a configuration in which a printed circuit board (not shown) on which an amplifier circuit 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 includes at least a case main body 32 that houses a signal amplification circuit. In this embodiment, the case main body 32 is a frame body that opens front and rear. When the printed wiring board on which the signal amplification circuit is formed is stored in the frame 32, the first reflection is performed so that the opening on the front side of the frame 32 is blocked by the first reflector 21 of the reflector 20. It is assembled so as to adhere to the vessel 21 without impairing the shielding property. When the frame 32 is assembled to the reflector, the signal amplification circuit 30 having excellent shielding properties is formed by closing the opening on the rear side of the frame 32 with the lid 33.
In addition, although the example which comprised the signal processing circuit 30 by the signal amplifier circuit was shown, for example, the mixing circuit which mixes the signal received with the antenna of this invention and the signal from an external antenna may be sufficient, and a signal amplification circuit and a mixing circuit are comprised. The present invention is not particularly limited to the embodiments, for example, it may be combined. In this case, 34 shown in the figure is an antenna output terminal, and 35 is an external antenna input terminal.

The signal processing circuit 30 is supplied with signals received by the antenna from the feeding 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. Reference numeral 23 denotes an insertion hole for inserting the unbalanced line 19 formed in the reflector, and is formed to have a size that does not affect the electrical characteristics of the antenna.
In the second embodiment of the present invention, the signal processing circuit 30 is mounted on the rear side of the first reflector 21. However, the signal processing circuit 30 is not particularly limited to this embodiment, and has an electrical characteristic. In a range where there is no influence, a part of the reflector may be used as a part of the shield case of the signal processing circuit 30, may be the front side of the reflector, or the reflector may be sandwiched. In particular, the attachment position is not limited.

As described above, according to the second embodiment of the present invention, a part of the reflector 31 is used as a part of the shield case 31 constituting the signal processing circuit 30 including the signal amplifier circuit and the like within a range where the electrical characteristics are not impaired. Thus, the signal processing circuit 30 can be accommodated in the antenna 1 without increasing the outer shape of the antenna 1. Further, the components of the shield case 31 can be reduced, the cost can be reduced, and the weight of the product can be reduced.

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 a schematic perspective view which shows the structure of 1st Example of the antenna which concerns on this invention. It is a schematic block diagram of the radiator which comprises the antenna of 1st Example. It is the schematic which shows the structure of the antenna of 1st Example, (a) is a right view, (b) is a top view. It is a front side schematic perspective view which shows the structure of the antenna of 2nd Example based on this invention. It is a back side schematic perspective view which shows the structure of the antenna of 2nd Example based on this invention. It is the schematic sectional drawing which cut | disconnected a part of antenna of 2nd Example. In the antenna of the second embodiment, the electrical characteristic data is obtained when the shape of the reflector is changed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Antenna, 4b * 42b * 41b ... Rib, 4c * 42c * 41c ... Bending part, 10 ... Radiator, 11 ... 1st radiator, 11a * 11b ... Radiation element, 12 ... 2nd radiator, 12a * 12b Radiating elements, 14 bending portions, 15 phase adjusting means, 16a and 16b feeding points, 17 balanced lines, 18 balanced / unbalanced conversion circuits, 19 unbalanced lines, 20 reflectors, 21st DESCRIPTION OF SYMBOLS 1 reflector, 22a * 22b ... 2nd reflector, 23 ... Insertion hole, 30 ... Signal processing circuit, 31 ... Shield case, 32 ... Frame body, 33 ... Cover body, 34 ... Antenna output terminal, 35 ... External antenna input Terminal.

Claims (5)

In an antenna with at least a radiator and a flat reflector,
The reflector has a longitudinal direction in a direction parallel to a polarization direction of a received radio wave, and a first reflection formed in a rectangular shape arranged substantially parallel to a plane orthogonal to the arrival direction of the radio wave. A vessel,
Both long sides of the first reflector are bent at the bent portions in the direction of the radiator, respectively, have a longitudinal direction parallel to the direction of polarization of the received radio wave, and the arrival direction of the radio wave And a second reflector formed in a rectangular shape arranged substantially parallel to a plane parallel to the antenna.
The antenna includes a signal processing circuit for processing a received signal accommodated in an electronic device box having shielding properties, and the electronic device box is configured using a part of the first reflector. The antenna according to claim 1.
The antenna according to claim 2, wherein the signal processing circuit is an amplifier circuit for amplifying a signal received by the antenna.
The signal processing circuit is a mixing circuit that mixes a signal received by the antenna and a signal received by an external antenna that receives a frequency band different from a signal of a frequency band received by the antenna. The antenna according to claim 2
According to a fifth aspect of the present invention, in the antenna according to any one of the first to fourth aspects, the frequency used is in the UHF band.

Images