JP4112456B2 - Polarized antenna device - Google Patents

Description

  The present invention relates to a single-polarized antenna device and a dual-polarized antenna device, and in particular, for example, for horizontal diversity or vertical polarization for space diversity used as a base station antenna in a mobile communication system or the like. The present invention relates to a single polarization antenna device for waves and a dual-polarized antenna device capable of independently transmitting and receiving two orthogonal polarizations such as horizontal polarization and vertical polarization to obtain a diversity effect.

  Conventionally, in order to increase the radio wave reception efficiency for this type of antenna device, the space diversity reception method has been used. However, the shape of the upper part of the tower for installing antennas has increased, and recently, a base such as the upper part of the tower has been used. Shifting to a polarization diversity reception system that can simplify station equipment.

  As a conventional dual-polarized antenna apparatus, (1) a dual-polarized antenna in which a parasitic element is added to two slot antennas substantially orthogonal to each other configured on a dielectric substrate, or (2) configured on a dielectric substrate A horizontally polarized antenna in which a parasitic element is added to the slot antenna to be formed, and a vertically polarized antenna composed of a dipole antenna formed by combining two surfaces on both sides of the horizontally polarized antenna. There is a vertical and horizontal polarization antenna.

  That is, as for the former, as shown in FIG. 11, for example, there is known a polarization sharing antenna apparatus 101 in which parasitic elements are added to two slot antennas that are substantially orthogonal to each other and are configured on a dielectric substrate. .

  Referring to FIG. 11, the dual-polarized antenna device 101 has two feeding slots 102 and 103 that are inclined by approximately 45 degrees with respect to the vertical line V from the horizontal plane toward the sky and intersect each other at substantially right angles. A ground conductor surface 104 has a dielectric plate 105 formed on the front surface, and two strip-shaped feed lines 107 disposed on the back surface of the dielectric plate 105 along the feed slots 102 and 103, respectively. 106.

The portion where the two belt-like feed lines 107 and 106 intersect each other is three-dimensionally crossed with the one feed line 107 so that one feed line 107 does not contact the other feed line 106. The detour 108 is formed, and the lengths of both the feed lines 107 and 106 from the tip to the respective feed terminals 107a and 106a are formed to be substantially the same length. In addition, a parasitic element 109 is disposed on the center axis O where the two feeding slots 102 and 103 intersect, in front of the surface side of the dielectric plate 105. Reference numeral 110 denotes a reflector made of a metal material. (Patent Document 1)
JP 2003-46326 A: Polarization dual antenna device (Japanese Patent Application No. 2001-233047)

Further, the latter as another conventional technique includes those shown in Japanese Patent Application No. 2002-246834 already proposed by the present applicant.
In other words, this technology is a vertically polarized antenna composed of a horizontally polarized antenna in which a parasitic element is added to a slot antenna formed on a dielectric substrate, and a dipole antenna composed of two surfaces disposed on both sides of the horizontally polarized antenna. This is a vertical and horizontal polarization antenna device in which a wave antenna is disposed on a single reflector.

However, the former polarization sharing antenna device of the prior art has a problem that the ratio band of the voltage standing wave ratio of the element alone is still narrower than the desired ratio band.
Further, the latter dual-polarized antenna device of the prior art has a problem that the structure becomes complicated and the manufacturing cost increases.

  The present invention has been made in view of the above points, and its object is to solve the above-described problems. For example, when used as a base station antenna for mobile communication, the voltage standing wave ratio can be widened without changing the occupied space. An object of the present invention is to provide a single-polarized or dual-polarized polarization antenna device that can obtain the desired characteristics.

  Another object of the present invention is to provide a single-polarized or dual-polarized polarization antenna device whose structure is simplified and whose manufacturing cost is reduced.

In order to achieve the above object, the configuration of the present invention radiates radio waves of two orthogonally polarized waves, and therefore, in both directions formed so that the centers are orthogonal to each other on two slot centerlines orthogonal to each other. A ground conductor surface on which two power supply slots having a symmetrical rod-shaped pincushion shape are provided, a dielectric substrate formed on the front surface, and a back surface of the dielectric substrate crossing the center of each of the power supply slots, and An antenna device including two strip-shaped feed lines formed so that respective center lines of the two feed slots are orthogonal to each other, and a parasitic element is disposed in front of the surface side of the dielectric substrate And it is as follows .
Here, the rod-like bobbin shape means that the length of a side in a direction perpendicular to the center line is symmetrically linearly as it proceeds from the center to the both end directions along the center line, for example, left and right end directions. The shape is proportionally longer (tapered).

The rod-shaped pincushion shape symmetrical in both directions of the power supply slot is a shape formed by joining two isosceles trapezoids that are equal to each other and short sides on the center line, and in each of the center line directions. The total length is 1/2 of the wavelength λ of the operating frequency, the width at each tip is 1/10 of the wavelength λ, and the width of the shorter side of each of the isosceles trapezoids is The width of the feed line is equal to or less than the width of the feed line, and the portion where the two belt-like feed lines intersect with each other is three-dimensionally intersected with the one feed line so that one feed line does not contact the other feed line. This is a polarization antenna device that forms a detour.

  In the polarization antenna device, a reflector is disposed behind the back surface of the dielectric substrate.

  A plurality of the polarization antenna devices are arranged in the horizontal direction or the vertical direction on the same dielectric substrate, or arranged side by side in the horizontal direction and the vertical direction, and are polarization antenna devices configured as array antennas. .

Since the present invention is configured as described above, when the polarization antenna apparatus of the present invention is used as, for example, a mobile communication base station antenna, the voltage standing wave ratio is much wider without changing the occupied sbase. Characteristics are required.
That is, according to the present invention, one (or one) parasitic element is formed by strengthening the coupling with the parasitic element by forming the feeding slot in a rod-like bobbin shape symmetrical in both directions, for example, the left and right directions. However, the voltage standing wave ratio can be widened, and the cross polarization characteristics are also improved.
In addition, since the antenna structure is also composed of the dielectric substrate and the parasitic element in this way, it can be reduced in size and simplified.

  According to the polarization antenna device of the present invention, each is configured as described above. Therefore, when the polarization antenna device is used as, for example, a base station antenna for mobile communication, the voltage standing wave is not changed without changing the occupied base. The characteristic that the ratio is widened is obtained, the structure is simplified, and the manufacturing cost can be reduced.

  In addition, since a plurality of the polarized antenna devices of the present invention are arranged in the horizontal direction and the vertical direction on the same dielectric substrate and configured as an array antenna, the space occupied by the antenna device is reduced. be able to.

  Hereinafter, the most preferred embodiment of the present invention will be described in detail with reference to the drawings.

  FIGS. 1 to 5 are diagrams showing Example 1 of the embodiment of the polarization antenna device of the present invention. FIG. 1 is a perspective view showing the configuration of the polarization antenna device 1 for single polarization as seen from the front side. 2 is a front view showing a feed slot 4 formed on the front surface of the dielectric substrate 2 in FIG. 1 and a feed line 4 formed on the back surface, and FIG. 3 is a diagram of the feed slot 4 shown in FIG. Detailed view, FIG. 4 is a diagram showing the directivity of the polarization antenna device of the present embodiment by a solid line, a diagram showing the directivity of the cross polarization component by a broken line, and FIG. 5 is a return of one element with respect to the frequency It is a loss characteristic figure.

  1 and 2, the polarization antenna device 1 used in the frequency 2 GHz band radiates a single-polarized wave (for example, a horizontal polarization or a vertical polarization), On one surface of the dielectric substrate (dielectric printed circuit board) 2, that is, the surface, a ground conductor surface 3 formed of metal foil is provided with a symmetrical rod-shaped bobbin-shaped feeding slot 4.

  In order to simplify the antenna structure, the other surface, that is, the back surface of the dielectric substrate 2 is fed with power to the power feeding slot 4 so as to cross the substantially central portion of the power feeding slot 4 on the front surface. A strip-shaped feed line 5 having an arbitrary width is formed by a metal foil so as to be substantially orthogonal to the center line O1, and the feed slot 4 is fed at the center feed point FP. At this time, the length from the feed point FP to the tip 5a of the feed line 5 is about ¼ of the wavelength λ of the operating frequency.

  In front of the surface side of the dielectric substrate 2, on a substantially central axis of the power supply slot 4, a side is formed of a substantially square metal plate having a length of about ½ of the wavelength λ of the operating frequency. The feeding element 6 is disposed in parallel with the dielectric substrate 2 by a support member (not shown) at a distance of about ¼ of the wavelength λ. The reflector 7 made of a metal plate on the substantially central axis of the power supply slot 4 is located at a predetermined distance suitable for the antenna device 1 with respect to the dielectric substrate 2 by a support member (not shown). Are arranged in parallel, spaced apart from each other.

  As shown in FIG. 3, the feeding slot 4 having a symmetrical rod-shaped bobbin shape formed in the dielectric substrate 2 is formed in the left and right end directions from the center of the dielectric substrate 2 along the center line O1. In addition, two isosceles trapezoids that are equal to each other are formed in a shape in which the shorter sides are joined to each other on the slot center line O1. The specific size is such that the total length of the feeding slot 4 in the direction of the slot center line O1 is about ½ of the wavelength λ of the operating frequency, and the width in the direction perpendicular to the slot center line O1 at both ends. The (side length) is about 1/10 of the wavelength λ.

  When the power of the frequency in the 2 GHz band is fed to the feeding slot 4 side by the feeding line 5, the polarization antenna device 1 is fed at the feeding point FP, and the surface side of the dielectric substrate 2 is A single-polarized radio wave is radiated by coupling with the parasitic element 6 disposed in front of the antenna.

In this case, the horizontal plane directivity of the polarized antenna device 1 when the polarized antenna device 1 radiates a single-polarized radio wave having a frequency of 2 GHz is indicated by a solid line in FIG. The directivity of the cross polarization component is indicated by a broken line. FIG. 4 shows the voltage standing wave ratio, that is, the return loss characteristic, obtained at a frequency near 2 GHz when the single polarized radio wave is radiated.
This shows that the voltage standing wave ratio is wider.

  6 to 9 are diagrams showing Example 2 of the embodiment of the polarization antenna device of the present invention, and FIG. 6 is a front side showing a configuration of the polarization antenna device 11 in the case of sharing two polarizations. FIG. 7 is a front view showing the feeding slots 4 and 14 formed on the surface of the dielectric substrate 2 of FIG. 6 and the two feeding lines 5 and 15 formed on the back surface. 8 is a detailed view of the power supply slots 4 and 14 shown in FIG. 7, and FIG. 9 is an enlarged perspective view showing the intersection of the two power supply lines 5 and 15 on the back side of FIG. The same members as those shown in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof is omitted.

  6 and 7, the two polarized wave shared antenna device 11 used in the frequency 2 GHz band radiates radio waves of two orthogonally polarized waves (for example, a horizontally polarized wave and a vertically polarized wave). On one surface of the dielectric substrate (dielectric printed circuit board) 2, that is, on the ground conductor surface 3 formed of metal foil, on the two slot center lines O 1 and O 2 orthogonal to each other in the figure, Two feeding slots 4 and 14 having the same rod-like bobbin shape, which are symmetrical with respect to the left and right and are vertically symmetrical, are provided so that the centers are orthogonal to each other.

  In order to simplify the antenna structure, the other surface of the dielectric substrate 2, that is, the back surface, is fed with power to the two power feeding slots 4 and 14, respectively. The two strip-shaped feed lines 5 and 15 having the same shape and having an arbitrary width are formed by a metal foil so as to cross substantially the central portion of the slot and to be substantially orthogonal to the slot center lines O1 and O2. The feeding slots 4 and 14 are fed at the respective feeding points FP at the center. At this time, the length from the feed point FP to the tips 5a and 15a of the feed lines 5 and 15 is about 1/4 of the wavelength λ.

  In front of the surface side of the dielectric substrate 2, on a substantially central axis of the power supply slots 4 and 14, a metal plate having a substantially square shape whose one side is about ½ of the wavelength λ of the operating frequency. The parasitic element 6 is disposed parallel to the dielectric substrate 2 by a support member (not shown) at a distance of about 1/4 of the wavelength λ, and the dielectric A reflector 7 made of a metal plate is disposed on the central axis of the power supply slots 4 and 14 behind the back side of the substrate 2 with respect to the dielectric substrate 2 by a support member (not shown). They are arranged in parallel, separated by a suitable predetermined distance.

As shown in FIG. 8, the feeding slots 4 and 14, which are formed in the dielectric substrate 2, are symmetrically and vertically symmetrical rod-shaped bobbin-shaped feeding slots 4, 14, and the two centers perpendicular to each other from the center of the dielectric substrate 2. Two isosceles trapezoids, which are formed along the lines O1 and O2 in the left and right and upper and lower end directions, respectively, and are identical to each other, have a shorter side on each of the slot center lines O1 and O2. It is formed in a shape that is in contact with each other. The specific size is that the total length of the power supply slots 4 and 14 in the respective directions of the slot center lines O1 and O2 is about ½ of the wavelength λ of the operating frequency, and the slot center lines O1 and O2 at both ends. The width (side length) in the direction perpendicular to O2 is about 1/10 of the wavelength λ.
Further, the width of the shorter side of the isosceles trapezoid of each of the feeding slots 4 and 14 is equal to the shorter side of the shorter side of the isosceles trapezoid of the vertical polarization feeding slot 4 as shown in the enlarged central part of FIG. The width of the shorter side of the isosceles trapezoid of the horizontal polarization feed slot 14 is set to be equal to or less than the width of the vertical polarization feed line 5.

  At this time, as shown in FIG. 9, the two strip-shaped feed lines 5 formed on the back surface of the dielectric substrate 2 so as to cross the substantially central portion of the feed slots 4 and 14 on the front surface. , 15 at a portion intersecting substantially at right angles, a detour 15b is formed to form a three-dimensional intersection with the one feed line 15 so that one feed line 15 does not come into contact with the other feed line 5. The length from the feed point FP of both feed lines 5 and 15 including the path 15b to the respective tips 5a and 15a is formed to be approximately ¼ of the wavelength λ having substantially the same length.

When the power of the frequency of the 2 GHz band is fed to the feeding slots 4 and 14 by the feeding lines 5 and 15, the polarization antenna device 11 is fed at the feeding point FP. 14 is coupled with the parasitic element 8 so that each polarized wave is radiated.
In this case, the directivity of the polarization antenna device 11 and the directivity of the cross polarization component when the radio waves of the respective polarizations of the 2 GHz band are radiated from the polarization antenna device 11, and The voltage standing wave ratio obtained at the frequency near 2 GHz when the radio waves of the respective polarizations are radiated, that is, the characteristics of the return loss are almost the same as in the first embodiment.

  FIG. 10 is a perspective view showing Example 3 of the embodiment of the polarization antenna device of the present invention. When the polarization antenna device 21 has a high gain, the polarization antenna device shown in Example 2 is used. 11 (or the polarization antenna device 1 shown in the first embodiment) may be arranged in a plurality of stages (two stages in this embodiment) in a vertical line in the vertical line V direction from the horizontal plane to the sky. It is configured as a vertical array antenna. At the same time, one dielectric plate 22 is arranged so that the dielectric substrates 2 and 2 are put together, and the parasitic elements 6 and 6 are individually arranged by support members (not shown). . In addition, one reflector 23 is provided by a support member (not shown) so that the reflectors 7 and 7 are put together.

  Further, the lateral width of the dielectric substrate 22 of the vertical polarization shared antenna device 21 is expanded in the horizontal direction (width direction) with respect to the vertical line V, and the feed lines 5, 15, 5, 15. , ... can be used as a power supply space by the corporate (tournament diagram) power supply system. For this reason, the whole dielectric substrate 22 can be reduced in size.

  Note that the technology of the present invention is not limited to the technology in the above-described embodiment, and may be implemented by means of other modes that perform the same function. Can be added.

It is a figure which shows Example 1 of embodiment of the polarization antenna apparatus of this invention, and is the perspective view seen from the front side which shows the structure of the polarization antenna apparatus for single polarization. It is a front view which shows the electric power feeding slot formed in the surface of the dielectric substrate of FIG. 1, and the electric power feeding line formed in a back surface. FIG. 3 is a detailed view of a power supply slot shown in FIG. 2. It is a figure which shows the directivity of the said polarization antenna apparatus and the directivity of a cross polarization component in a present Example, A solid line shows the horizontal plane directivity of the said polarization antenna apparatus, and a broken line shows the directivity of a cross polarization component. Show. It is a return loss characteristic figure of one element to the frequency of the polarization antenna device. It is a figure which shows Example 2 of the polarization antenna apparatus of this invention, and is the perspective view seen from the front side which shows the structure in the case of sharing of two polarized waves of a polarization antenna apparatus. FIG. 7 is a front view showing a feed slot, four impedance matching stubs, and two feed lines formed on the back surface formed on the surface of the dielectric substrate of FIG. 6. FIG. 8 is a detailed view of the power feeding slots 4 and 14 shown in FIG. 7. It is a perspective view which expands and shows the cross | intersection part of the two feeder lines in the back side of FIG. FIG. 9 is a diagram showing a third embodiment of the polarized antenna device of the present invention, and in the case of sharing two polarized waves of the polarized antenna device, a plurality of stages (2 in the present embodiment) in the vertical line V direction from the horizontal plane to the sky. FIG. 2 is a perspective view showing a configuration as a vertical array antenna in which columns) are arranged in columns. It is a perspective view which shows the polarization sharing antenna apparatus among the conventional antenna apparatuses.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11,21 Polarized-wave antenna apparatus 2,22 Dielectric board | substrate 3 Ground conductor surface 4 Feed slot 5,15 Feed line 5a, 15a Tip 6 Parasitic element 7, 23 Reflector 15b Detour FP Feed point V Vertical line

Claims (3)

In order to radiate radio waves of two orthogonally polarized waves, two feeding slots each having a rod-like pincushion shape symmetrical in both directions are formed on the two slot center lines orthogonal to each other so that the respective centers are orthogonal to each other. A dielectric substrate having a ground conductor surface formed on the surface;
On the back surface of the dielectric substrate, there are provided two strip-shaped feed lines that are formed so as to cross the centers of the feed slots and to be orthogonal to the center lines of the two feed slots. ,
An antenna device in which a parasitic element is disposed in front of the surface side of the dielectric substrate,
The rod-shaped pincushion shape symmetrical in both directions of the power supply slot is a shape formed by joining two isosceles trapezoids that are equal to each other and short sides on the center line, and in each of the center line directions. The total length is 1/2 of the wavelength λ of the operating frequency, the width at each tip is 1/10 of the wavelength λ, and the width of the shorter side of each of the isosceles trapezoids is Less than the width of the feed line,
Furthermore, the portion where the two belt-like feed lines intersect with each other is characterized in that a bypass is formed on the one feed line so that one feed line does not come into contact with the other feed line. Polarized antenna device. The polarization antenna device according to claim 1, wherein a reflector is disposed behind the back side of the dielectric substrate . A plurality of the polarization antenna devices are arranged in the horizontal direction or the vertical direction on the same dielectric substrate, or arranged side by side in the horizontal direction and the vertical direction, and configured as an array antenna. The polarization antenna device according to claim 1 or 2 .