JP2005341376A - Opposite phase power supply antenna device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an opposite phase power supply antenna device for obtaining high gain, wide-band, and unidirectional directivity while the device is made small. <P>SOLUTION: An antenna unit 12 is provided on a reflective plate 11. In the antenna unit 12, two antenna substrates 21, 22 are provided opposite with a prescribed space on a round grounding plate 20, and a power supply substrate 23 is provided in between. Each inphase dipole element and each opposite phase dipole element are provided with a prescribed space on the antenna substrates 21, 22. A power supply line is provided at the power feeding substrate 23 and the power feeding unit is fed with power through a power supply cable 32 and a power supply connector 31 from the outside. In the power supply substrate 23, a signal fed with power through the power supply connector 31 is fed to the inphase dipole element and the opposite phase element on the antenna substrates 21, 22 through a power feeding line. In this case, the opposite phase element is fed with power in the phase, which is made opposite to the inphase dipole element. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a negative-phase feed antenna device used as a relay antenna for, for example, a third generation mobile phone.

  In recent years, mobile phones have been widely used and used in trains and the like. When using a mobile phone in a train, radio waves are hardly blocked by obstacles when the train is running on the ground, so it is possible to talk without problems, but the train is in the tunnel. If you enter, the radio wave will be cut off and you will not be able to talk. For this reason, conventionally, a relay antenna is installed near the entrance of the tunnel or in the tunnel so that the mobile phone can be used in the car even when the train enters the tunnel.

  The antenna used in the vicinity of the entrance of the tunnel is required to have high gain and wideband characteristics having directivity in the inner direction of the tunnel. Conventionally, a multi-element Yagi-type antenna has been used as a high-gain, wide-band directional antenna.

  When the frequency band is wide, the multi-element Yagi antenna adjusts the length and spacing of each element while measuring the directivity, so it takes a long time to adjust. This makes the manufacturing difficult. The third-generation mobile phone uses a very high frequency of 2 GHz, so there is a problem that it is difficult to cope with the multi-element Yagi antenna. In addition, the multi-element Yagi antenna is difficult to miniaturize because a large number of elements are arranged at predetermined intervals.

In addition, as a conventional antenna that can be reduced in size compared to a multi-element Yagi type antenna, two dipole elements are arranged in parallel at an interval of a quarter wavelength (λ) and are fed in reverse phase. A beam antenna is known (for example, see Non-Patent Document 1). In this flat top beam antenna, both the front and rear directions are the maximum radiation directions.
JOHN D.KRAUS, Ph.D., translated by Isao Tanimura, “Aerial Line [Volume 2]”, p. 344-350, January 15, 1958, published by Modern Science

  Conventional multi-element Yagi-type antennas take a long time to adjust the length and spacing of each element while measuring the directivity when the frequency band is wide. Since the size is required, there are problems such as difficulty in manufacturing and difficulty in miniaturization.

  In addition, a flat-top beam antenna in which two dipole elements are arranged in parallel at an interval of a quarter wavelength and fed with opposite phase power is radiated in both the front and rear directions. It is not suitable as a telephone relay antenna.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a negative-phase feed antenna device capable of obtaining high gain and wideband unidirectional directivity while achieving downsizing.

  A negative-phase feeding antenna device according to a first aspect of the present invention includes an antenna substrate, an in-phase dipole element and an anti-phase dipole element formed opposite to each other on the antenna substrate, and a feed phase of the in-phase dipole element. It is characterized by comprising feeding means for feeding power to the phase dipole element in opposite phase, and a reflector provided behind the opposite phase dipole element.

  A negative phase feeding antenna device according to a second aspect of the present invention includes a first antenna substrate, a second antenna substrate provided at a predetermined interval with respect to the first antenna substrate, and the first and second antennas. On the substrate, the in-phase dipole element and the opposite-phase dipole element formed opposite to each other, and the opposite-phase dipole element with respect to the feeding phase of the in-phase dipole element formed on the first and second antenna substrates. It is characterized by comprising feeding means for feeding in phase and a reflector provided behind the first and second antenna substrates on the opposite phase dipole element side.

  According to a third aspect of the present invention, in the negative-phase feed antenna device according to the first or second aspect of the invention, the elements constituting the in-phase dipole element and the anti-phase dipole element are formed by tilting each other by a predetermined angle. And

  According to the present invention, the in-phase dipole element and the anti-phase dipole element are formed on the antenna substrate, respectively, and the anti-phase dipole element is fed in the opposite phase to the feeding phase of the in-phase dipole element and By providing a reflector on the surface, the size can be reduced with a very simple configuration, and high-gain, wide-band unidirectional directivity can be obtained. Further, by forming a dipole element on the antenna substrate, the element dimensions can be made highly accurate, and it is possible to easily cope with a high frequency in the GHz band. Furthermore, after manufacturing the antenna, it is not necessary to adjust the element spacing and the like, and the manufacturing efficiency can be significantly improved. In addition, the directivity and gain can be further improved by providing the first and second antenna substrates at predetermined intervals. Further, by forming the elements constituting the in-phase dipole element and the anti-phase dipole element so as to be inclined by a predetermined angle, the frequency band can be further widened.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a basic configuration diagram of a negative-phase feed antenna apparatus according to an embodiment of the present invention.
As shown in FIG. 1, an in-phase dipole element 1 and a negative-phase dipole element 2 having a length L are arranged at a predetermined interval a, and reverse-phase power is supplied through a power supply line 3. In other words, power is supplied by arranging the positive (+) and negative (−) element relations of the antenna in the in-phase dipole element 1 and the anti-phase dipole element 2 in reverse. In this case, power may be supplied by providing a phase difference of 180 ° by the power supply line 3.

  The in-phase dipole element 1, the opposite-phase dipole element 2, and the feed line 3 are formed by means such as vapor deposition of metal foil on an antenna substrate (not shown), for example. The length L of the in-phase dipole element 1 and the opposite-phase dipole element 2 is set to about λ / 2 (λ: wavelength of the used frequency), and the distance a between the in-phase dipole element 1 and the opposite-phase dipole element 2 is about 0. Set to 5λ or less.

  For example, a rectangular reflector 4 is disposed behind the reversed-phase dipole element 2 with a predetermined interval. The reflecting plate 4 may be a plate in which a plurality of metal bars are arranged on the same surface at regular intervals. The reflector 4 is disposed at a distance b from the center position between the in-phase dipole element 1 and the reverse-phase dipole element 2. The interval b is about 0.6λ or less.

  With the above configuration, radio waves are radiated forward and backward from the in-phase dipole element 1 and the reverse-phase dipole element 2, and the radio waves radiated backward are reflected by the reflector 4 and radiated forward. In this case, the radio wave reflected by the reflecting plate 4 is synthesized in phase with the radio wave radiated forward, so that the radiation intensity of the radio wave is increased.

  FIG. 1 shows the case where one antenna substrate provided with the in-phase dipole element 1 and the anti-phase dipole element 2 is provided. For example, about 0.5 to 0.7λ, and the reflector 4 is arranged behind them for common use. In this case, the two antenna substrates are arranged so that the in-phase dipole element 1 and the anti-phase dipole element 2 are symmetrical. Thus, antenna gain can be greatly improved by using two antenna substrates.

  Next, a specific configuration example of the negative-phase feed antenna device according to the embodiment of the present invention will be described. 2A and 2B show the overall external configuration of the negative-phase feed antenna apparatus according to the embodiment, where FIG. 2A is a front view, FIG. 2B is a left side view, and FIG. 2C is a top view. 3A and 3B show the internal structure of the negative-phase feed antenna device, where FIG. 3A is a cross-sectional view and FIG. 3B is a side cross-sectional view showing a cross section of the antenna cover portion.

  In FIG. 2, reference numeral 10 denotes an antenna body, which includes, for example, a rectangular reflector 11, an antenna unit 12 shown in FIG. 3 provided on the reflector 11, and a resin antenna cover 13 that protects the antenna unit 12. Yes. Each side of the reflector 11 is set to about 20 cm to 23 cm, for example.

  The reflection plate 11 is formed of a metal plate and also serves as an antenna holding substrate, and a base portion of the antenna cover 13 is fixed to the upper surface of the reflection plate 11 by a plurality of screws 14. As shown in FIG. 3A, the antenna cover 13 is provided with a drain hole 19 below the tip portion.

  Moreover, the periphery of the reflecting plate 11 is bent sideways, and the upper and lower bending widths are set longer than the left and right bending widths. A column mounting bracket 16 is fixed to the upper and lower bent portions 15 with bolts and nuts 17. The antenna body 10 is attached to the column 18 by a column mounting bracket 16.

  FIG. 4 is a perspective view showing the antenna portion 12 taken out. The antenna unit 12 includes, for example, a circular ground plate 20 (metal plate) and a first antenna substrate 21, a second antenna substrate 22, and a power supply substrate 23 provided on the ground plate 20. As described above, the first antenna substrate 21 and the second antenna substrate 22 are provided to face each other at an interval of about 0.5 to 0.7λ, for example, and the power supply substrate 23 is provided therebetween. A plurality of, for example, four substrate spacers 24 are interposed between the antenna substrates 21 and 22 on both sides, and are fixed by screws 25. The substrate spacer 24 is formed, for example, in a round bar shape by an insulating material. The antenna substrates 21 and 22 and the power supply substrate 23 are formed of an insulating material (dielectric material), and are fixed to the ground plate 20 by screws or the like via a support member. An antenna pattern is formed on the antenna substrates 21 and 22, and a power supply pattern is formed on the power supply substrate 23. The details will be described later.

  The ground plate 20 is provided with a power feeding through hole 26 and a plurality of, for example, four mounting holes 27 in the periphery. The ground plate 20 is fixed on the reflecting plate 11 by bolts and nuts 28 as shown in FIG.

  As shown in FIGS. 3 and 4, the power supply board 23 is connected with a power supply connector 31 to a power supply portion on the side of the ground pattern 52, which will be described in detail later. The power supply connector 31 is connected to a power supply cable 32, and a connector 33 is provided at the tip thereof. The connector 33 is connected to the external connector 34 through a plug attached to the reflecting plate 11 at a portion of the power feeding through hole 26 provided in the ground plate 20. The external connector 34 is provided on the back side of the reflecting plate 11 and led out to the outside via a coaxial cable 35. A connector 36 is provided at the tip of the coaxial cable 35 and is connected to a transmission / reception device (not shown).

  FIG. 5 shows an example of an antenna pattern formed on the first antenna substrate 21. (a) is an antenna pattern 40a formed on the front surface (outer surface), and (b) is formed on the back surface. This is an antenna pattern 40b. These antenna patterns 40a and 40b are formed by evaporating a metal foil on the antenna substrate 21, for example.

  As shown in FIG. 5A, on the surface of the antenna substrate 21, in-phase dipole elements 41a and 41b are provided on the upper side, and anti-phase dipole elements 42a and 42b are provided on the lower side with an interval of about 0.5λ or less. . In this case, the in-phase dipole elements 41a and 41b and the reverse-phase dipole elements 42a and 42b are formed so as to be inclined by, for example, about 23 ° to 24 ° from the reference horizontal position. By forming the dipole elements 41a, 41b, 42a, and 42b to be inclined as described above, it is possible to further increase the bandwidth. The in-phase dipole elements 41a and 41b and the anti-phase dipole elements 42a and 42b have a total length of about λ / 2. Further, the distance between the center position of the in-phase dipole elements 41a and 41b and the reverse-phase dipole elements 42a and 42b and the reflecting plate 11 shown in FIGS. 2 and 3 is set to about 0.6λ or less.

  A feed line pattern 43 that connects the in-phase dipole element 41a and the anti-phase dipole element 42b and connects the in-phase dipole element 41b and the anti-phase dipole element 42a is provided in an X shape. In this case, a pattern for connecting the in-phase dipole element 41a and the anti-phase dipole element 42b is formed by two thin line patterns 44 that are parallel to each other at a constant interval, and a feed line 45 is formed along the center thereof. That is, a coaxial line is formed by the feed line 45 and the line patterns 44 on both sides thereof. A feeding point 46 is provided in the center of the feeding line 45. The feed point 46 is fed by a feed line on the feed board 23 on the back side of the antenna board 21.

  The feed line 45 on the upper side from the feed point 46 passes through the inside of the in-phase dipole element 41a while being insulated, and is connected to the in-phase dipole element 41b. In addition, the lower feed line 45 from the feed point 46 passes through the inside of the negative phase dipole element 42b while being insulated, and is connected to the negative phase dipole element 42a. That is, for the in-phase dipole elements 41a and 41b, minus (−) power is supplied to the element 41a, plus (+) power is supplied to the element 41b, and plus (+) to the element 42a for the negative-phase dipole elements 42a and 42b. ) Feed, minus (-) feed to the element 42b, and reverse-phase feed between the in-phase dipole elements 41a and 41b and the reverse-phase dipole elements 42a and 42b.

  The in-phase dipole elements 41a and 41b, the reverse-phase dipole elements 42a and 42b, and the feed line pattern 43 are electrically connected to the antenna pattern 40b on the back surface side shown in FIG. . The plurality of through holes 47 are provided, for example, at intervals of about 0.1λ so that the antenna pattern 40a on the front surface side and the antenna pattern 40b on the back surface side are equivalently integrated. Further, an impedance adjustment pattern 48 is provided in the vicinity of the upper center of the in-phase dipole elements 41a and 41b.

The antenna pattern 40b provided on the back surface of the antenna substrate 21 is formed in substantially the same shape as the antenna pattern 40a provided on the front surface, but portions corresponding to the line pattern 44 and the feed line 45 are formed entirely. . Also, an impedance adjustment pattern 49 is provided at a position corresponding to the impedance adjustment pattern 48 on the front side.
Further, four through holes 50 for fixing the substrate spacer 24 shown in FIGS. 3 and 4 with screws 25 are provided on the left and right sides of the antenna substrate 21.

  The second antenna substrate 22 is formed with the same pattern as the antenna patterns 40a and 40b of the first antenna substrate 21. However, the antenna patterns 40a and 40b of the first antenna substrate 21 and the antenna pattern of the second antenna substrate 22 are formed so as to be reversed in the left and right directions.

  FIG. 6 shows an example of a power supply line pattern formed on the power supply substrate 23. (a) is a power supply line pattern 51 formed on the front surface, and (b) is a ground pattern 52 formed on the back surface. . As shown in FIG. 6A, a feed line 53 is provided on the surface of the feed board 23. The feed line 53 forms a coaxial line by, for example, a T-shaped feed line 54 and two thin line patterns 55 provided in parallel at regular intervals on both sides thereof. Both left and right ends of the feed line 54 are formed toward feed points 46 provided on the antenna pattern 40b on the back side of the antenna substrates 21 and 22, and feed pins (not shown) are used for each feed point 46. Connected by soldering. Further, a portion provided downward from the central portion of the power supply line 54 is connected to a power supply portion 56 provided substantially at the central portion of the power supply substrate 23.

  Further, a ground pattern 52 is provided on the back surface of the power supply substrate 23 as shown in FIG. The ground pattern 52 is formed in substantially the same shape as the feed line pattern 51 provided on the surface of the feed board 23. The feed line pattern 51 and the ground pattern 52 are provided at positions facing each other via the feed board 23 and are electrically connected by a plurality of through holes 57 provided at intervals of 0.1λ or less. The power feeding portion 56 provided on the front surface of the power feeding substrate 23 is led out through a through hole on the back surface of the power feeding substrate 23, and the power feeding connector 31 is mounted on the back surface side as shown in FIGS. Is done. In the power supply connector 31, a fixed-side plug is fixed to a hole 58 provided on both sides of the power supply unit 56 by screwing or the like, and a central conductor of the plug is connected to the power supply unit 56 by soldering or the like. .

  In the negative-phase feeding antenna device according to the embodiment, in-phase dipole elements 41 a and 41 b and negative-phase dipole elements 42 a and 42 b are formed on the antenna substrates 21 and 22, respectively, and the two antenna substrates 21 and 22 are placed on the reflector 11. Therefore, it is possible to reduce the size with a very simple configuration and to obtain directivity in one direction with a high gain and a wide band. In addition, for example, metal foil is vapor-deposited on the antenna substrates 21 and 22 to form the in-phase dipole elements 41a and 41b and the reverse-phase dipole elements 42a and 42b, so that the element dimensions can be made highly accurate and the GHz band is high. It is possible to easily cope with the frequency. Moreover, since it is not necessary to adjust the element spacing after determining the element dimensions, the production efficiency can be significantly improved. Further, by forming the in-phase dipole elements 41a and 41b and the anti-phase dipole elements 42a and 42b so as to be inclined by a predetermined angle, the frequency band can be further widened.

  Next, FIG. 7 to FIG. 11 show the results of measuring the standing wave ratio (VSWR) and the directivity by setting the antiphase feeding antenna device configured as described above as a vertically polarized antenna of 2 GHz band. In this case, the reception band was set to 1920-1980 MHz, and the transmission band was set to 2110-2170 MHz. The reception band and the transmission band are bands set as communication frequencies for a third generation mobile phone, for example. Further, as a relay antenna for a third generation mobile phone, for example, a standing wave ratio characteristic of “1.5 or less” and a gain of “11 dBi or more” are required.

  FIG. 7 shows the standing wave ratio characteristics of the vertically polarized antenna, with the horizontal axis representing frequency (MHz) and the vertical axis representing standing wave ratio. In FIG. 7, point a is a standing wave ratio at a low frequency (1920 MHz) in the reception band and is “1.31”, and point b is a standing wave ratio at a high frequency (1980 MHz) in the reception band. The point c is “1.10” at the standing wave ratio at the low frequency (2110 MHz) of the transmission band, and the point d is “1.40” at the standing wave ratio at the high frequency (2170 MHz) of the transmission band. there were. As described above, the standing wave ratio characteristic is “1.31” or less in the reception band and “1.40” or less in the transmission band, and “1”, which is the standard value of the third-generation mobile phone antenna. .5 or less ".

  FIG. 8 shows the vertical polarization vertical plane directivity in the reception band, where (a) is the low frequency “1.92 GHz” and (b) is the high frequency “1.98 GHz”.

  FIG. 9 shows the vertical polarization vertical plane directivity in the transmission band, where (a) is the low frequency “2.11 GHz” and (b) is the high frequency “2.17 GHz”.

  FIG. 10 shows the vertical polarization horizontal plane directivity in the reception band, where (a) is the low frequency “1.92 GHz” and (b) is the high frequency “1.98 GHz”.

  FIG. 11 shows the vertical polarization horizontal plane directivity in the transmission band, where (a) is the low frequency “2.11 GHz” and (b) is the high frequency “2.17 GHz”.

As described above, in the vertical polarization vertical plane and horizontal plane directivity, a beam-like directivity in the front direction was obtained. The gain is
Reception frequency 1.92 GHz: 11.76 dBi
1.98 GHz: 11.27 dBi
Transmission frequency 2.11 GHz: 11.50 dBi
2.17 GHz: 11.30 dBi
It sufficiently satisfies the standard value [11 dBi] or more.

  The above gain corresponds to the gain of a multi-element Yagi antenna having a 12-element configuration.

  According to the anti-phase feed antenna device shown in the above embodiment, the characteristic sufficiently satisfying the standard value was obtained as is apparent from the characteristic diagrams shown in FIGS. In addition, since the opposite-phase feed antenna device according to the above embodiment can obtain desired characteristics by arranging the two antenna substrates 21 and 22 to face each other at a predetermined interval, the size can be reduced as compared with the multi-element Yagi antenna. Can be achieved.

  In the above embodiment, the case where the antenna device is configured by using the two antenna substrates 21 and 22 has been described. However, the antenna device can be configured by only one antenna substrate.

  Further, the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying constituent elements without departing from the scope of the invention in the implementation stage.

It is a basic lineblock diagram of the antiphase feed antenna device concerning one embodiment of the present invention. The specific external appearance structural example of the negative phase electric power feeding antenna apparatus which concerns on the embodiment is shown, (a) is a front view, (b) is a left view, (c) is a top view. The internal structure of the reverse phase electric power feeding antenna apparatus which concerns on the embodiment is shown, (a) is sectional drawing, (b) is a sectional side view which shows an antenna cover part in cross section. It is a perspective view which takes out and shows the antenna part in the embodiment. In the embodiment, an example of an antenna pattern formed on the first antenna substrate is shown, (a) is an antenna pattern formed on the front surface, and (b) is an antenna pattern formed on the back surface. In the embodiment, an example of a pattern of a feed line formed on the feed board is shown, (a) is a feed line pattern formed on the front surface, and (b) is an earth pattern formed on the back surface. It is a figure which shows the standing wave ratio characteristic of the negative phase electric power feeding antenna apparatus which concerns on the same embodiment. It is a figure which shows the vertical polarization vertical surface directivity in the receiving band of the negative phase feeding antenna apparatus which concerns on the same embodiment. It is a figure which shows the vertical polarization vertical surface directivity in the transmission band of the negative phase feeding antenna apparatus which concerns on the same embodiment. It is a vertical polarization horizontal plane directivity in the reception band of the negative phase feeding antenna device according to the embodiment. It is a figure which shows the vertical polarization horizontal surface directivity in the transmission band of the negative phase electric power feeding antenna apparatus which concerns on the same embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... In-phase dipole element, 2 ... Reverse phase dipole element, 3 ... Feeding line, 4 ... Reflector plate, 10 ... Antenna main body, 11 ... Reflector plate, 12 ... Antenna part, 13 ... Antenna cover, 14 ... Screw, 16 ... Metal fittings 17 ... Nut, 18 ... support, 19 ... drain hole, 20 ... ground plate, 21 ... first antenna substrate, 22 ... second antenna substrate, 23 ... feeding substrate, 24 ... substrate spacer, 25 ... screw, 26 ... Power feed through hole, 27 ... Hole, 28 ... Nut, 31 ... Power feed connector, 32 ... Power feed cable, 33 ... Connector, 34 ... External connector, 35 ... Coaxial cable, 36 ... Connector, 40a ... Antenna pattern, 40b ... Antenna pattern, 40a, 40b ... Antenna pattern, 41a, 41b ... In-phase dipole element, 42a, 42b ... Reversed-phase dipole element, 43 ... Feed line pattern , 44 ... Line pattern, 45 ... Feed line, 46 ... Feed point, 47 ... Through hole, 48, 49 ... Impedance adjustment pattern, 50 ... Through hole, 51 ... Feed line pattern, 52 ... Ground pattern, 53 ... Feed Line, 54 ... feed line, 55 ... line pattern, 56 ... feed section, 57 ... through hole, 58 ... hole.

Claims (3)

  An antenna substrate, an in-phase dipole element and an anti-phase dipole element that are formed opposite to each other on the antenna substrate, and a power feeding unit that feeds the anti-phase dipole element in an opposite phase to the power feeding phase of the in-phase dipole element; A negative phase feeding antenna device comprising a reflector provided behind the negative phase dipole element.   A first antenna substrate, a second antenna substrate provided at a predetermined interval with respect to the first antenna substrate, and an in-phase formed opposite to each other on the first and second antenna substrates. A dipole element and a negative-phase dipole element; and a power supply means for supplying power to the negative-phase dipole element in reverse phase with respect to the power supply phase of the in-phase dipole element formed on the first and second antenna substrates; A negative-phase feeding antenna device comprising a reflector provided behind the negative-phase dipole element side with respect to the second antenna substrate.   3. The negative-phase feed antenna device according to claim 1, wherein the elements constituting the in-phase dipole element and the negative-phase dipole element are formed to be inclined at a predetermined angle.

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