JP2005210517A - Method for arraying array antenna, multi-frequency common antenna assembly, and arrival direction estimating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-frequency common antenna assembly which can be used in common for a plurality of frequencies, arrangement of an array antenna constituting the multifrequency common antenna assembly, and an arrival direction estimating device, capable of measuring arrival directions of arrival waves of a plurality of frequencies with a single device. <P>SOLUTION: The multi-frequency common antenna assembly is equipped with a plurality of array antennas (1, 2, and 3) constituted of a plurality of antennas, connection parts (4d1 and 4d2) for connecting the antennas of the plurality of array antennas, and a feed part (5) which performs transmission to and reception from the antennas; and the plurality of array antennas are arranged in layers by transmission/reception frequencies and performs transmission and reception of different frequencies, by using the same feed part in common. The respective array antennas are arranged in layers, to constitute an apparently single antenna, antennas which are in mutually corresponding relation among the respective layers are connected by a connection part, and one-end sides of the antennas are fed by the feed part, which is thus used in common for the plurality of frequencies. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a wireless communication system, and more particularly to an arrival direction estimation device that estimates an arrival direction of an incoming wave, a multi-frequency shared antenna device applied to this device, and an array antenna arrangement method provided in the multi-frequency shared antenna device. It is.

  With the widespread use of mobile phones and the like, the importance of monitoring control of radio wave usage and radio wave sensitivity of radio base stations and mobile terminals is increasing. For example, in the area design, it is necessary to adjust the installation movement and tilt of the base station antenna so that there is no leakage of the service target area of the mobile terminal network and sufficient communication quality can be provided.

  In urban areas and urban areas, multipath fusion exists due to reflection, diffraction, and scattering of radio waves by high-rise buildings. In CDMA communication, rake reception is performed by combining the delay times of the received radio waves of each path, and there may be a case where radio waves that exceed the rake fingers corresponding to the number of paths to be combined may arrive. When radio waves that exceed the influence of such multipath fusion or rake fingers arrive, a singular point that makes it difficult to ensure sufficient communication quality may occur. In area design, it is desirable to consider such problems. For this purpose, it is necessary to estimate the direction of arrival of incoming waves, the estimation of electrolytic strength, the identification of a base station using a pilot signal, and the like.

  In addition, there is a problem that communication quality deteriorates due to radio waves from an illegally installed booster. For this purpose, it is necessary to estimate the arrival direction of the incoming wave and specify the installation position of the illegal booster. Since the area to be investigated is very large in the estimation of the incoming wave, it is desirable to perform real-time processing while driving the vehicle equipped with the incoming wave estimation device.

  As a method for checking the reception status of radio waves, a method is known in which a highly directional antenna such as a parabolic antenna is mechanically rotated to measure the frequency characteristics of the propagation path and the direction of the incoming wave from the angle and received signal strength. (For example, Non-Patent Document 1).

  In the method using the parabolic antenna, a directional antenna having a large aperture area and a driving device for rotating the antenna are necessary in order to improve the angular resolution. It has been pointed out.

  In addition, the delay profile measurement is performed while moving the omnidirectional antenna on a straight line at a constant speed, the Doppler spectrum of the incoming wave is obtained by Fourier transforming the measurement result, and the arrival direction is determined from the relationship between the Doppler shift and the arrival direction. An estimation method has also been proposed (for example, Non-Patent Document 2).

  With this method of moving the omnidirectional antenna, it is possible to continuously estimate the direction of arrival at each position, but it is not possible to separate a symmetric direction with respect to the traveling direction, the angle resolution is inferior, etc. A point has been pointed out.

Radio waves from the base station arrive from various directions in the horizontal plane, and the incoming waves may be close in angle. Therefore, a system for estimating an incoming wave by a MUSIC (Multiple Signal Classification) method (for example, Non-Patent Document 3) or an ESPRIT (Estimation of Signal Parameters via Rotational Invariance Techniques) method (for example, Non-Patent Document 4) using a rectangular array antenna. (For example, Non-Patent Document 5) is known. In the rectangular array antenna, the forward / backward (F / B) spatial averaging method (for example, Non-Patent Document 5) is used to estimate the arrival direction of the correlation wave. It has also been proposed to estimate an incoming wave by the MUSIC method or ESPRIT method using a circular array antenna.
Shuji Sakagami, "900MHz band multipath propagation characteristics in mobile communication channels-Amplitude-Frequency characteristics-," Science theory (B), vol, J-70-B, no. 12, pp.1522-1582, Dec. 1987. Takeo Ohgane, Seiichi Sampei, Kyohide Kamio, Shuichi Sasaoka, Mitsuhiko Mizuno, “Characteristics of Multipath on Land Movement in Urban and Suburban Areas”, Science (B-II), vol, J-72-B-II , Pp.62-71, Feb.1989. ROSchmidt, “Mulitple Emitter Location and Signal Parameter Estimation” IEEE Trans. Antenna & Propagate., Vol. 34, No. 3, pp. 276-280, Mar. 1986. R.Roy and T.Kailath, “ESPRIT-Estimation of Signal Parameters via Rotational Invariance Techniques,” IEEE Trans.Accoust., Sppech & Signal Proc., Vol.37, pp.984-995, July.1989. Nobuyoshi Kikuma, “Adaptive signal processing by array antenna”, Science and Technology Publishing, 1998

  A plurality of different frequencies are used in the communication system. For example, mobile phones use different frequencies such as 900 MHz, 1.5 GHz, and 2.0 GHz. Radio waves of each frequency are transmitted from different radio stations. In order to estimate the arrival directions of radio waves having different frequencies, it is necessary to prepare an antenna corresponding to each frequency. In order to receive radio waves of each frequency with an array antenna, it is necessary to arrange the intervals between the antennas to be equal to or less than a half wavelength of the frequency.

  FIG. 11 is a schematic diagram for explaining the arrangement of each antenna of the array antenna. FIGS. 11A and 11B are examples of rectangular array antennas. Each antenna is arranged in a rectangular shape, and the distance between adjacent antennas on the side is a half wavelength of the frequency to be received. FIG. 11A shows an example of a rectangular arrangement for the reception frequency f1 (wavelength λ1), and FIG. 11B shows an example of a rectangular arrangement for the reception frequency f2 (wavelength λ2). The distance between the antennas is λ1 / 2 and λ2 / 2, which are half wavelengths. When the frequency f2 is higher than the frequency f1, the distance λ1 / 2 between the antennas of the array antenna that receives the frequency f1 is longer than the distance λ2 / 2 between the antennas of the array antenna that receives the frequency f2. Therefore, it is not possible to receive each frequency with one antenna, and it is necessary to prepare an array antenna for each frequency.

  The same applies to the circular array antenna. FIGS. 11C and 11D show examples of circular array antennas, in which each antenna is arranged in a circular shape, and the distance between adjacent antennas on the circumference is a half wavelength of the frequency to be received. FIG. 11C shows an example of a rectangular array for the reception frequency f1 (wavelength λ1), and FIG. 11D shows an example of a rectangular array for the reception frequency f2 (wavelength λ2). Even in a circular array antenna, each frequency cannot be received by one antenna, and it is necessary to prepare an array antenna for each frequency. The rectangular array antenna shown in FIGS. 11A and 11B shows an example in which the number of elements is 9, and the circular array antenna shown in FIGS. 11C and 11D shows an example in which the number of elements is 8. Yes.

  In either of the rectangular array antenna and the circular array antenna, in order to receive a plurality of frequencies, an array antenna is required for each frequency, and the arrangement interval of each antenna is different, so that an arrangement corresponding to each antenna is required.

  In addition, in order to estimate the direction of arrival of an incoming wave with an array antenna, the received signal received by each antenna of the array antenna is subjected to the MUSIC method, ESPRIT method, Forward / Backward (F / B) spatial averaging method, etc. Signal processing. Therefore, each antenna of the array antenna needs to be connected to the power feeding unit.

  FIG. 12 is a schematic diagram for explaining a relationship between an antenna and a power feeding unit in a conventional arrival wave estimation apparatus. When estimating the arrival directions of two incoming waves of frequencies f1 and f2, array antennas corresponding to the respective frequencies are arranged. Each array antenna is provided with a feeding unit, and estimates the direction of arrival of each incoming wave independently of each other.

  Therefore, in order to estimate an incoming wave for a plurality of frequencies in an incoming wave estimation device, an array antenna is provided for each frequency to be measured, and a power feeding unit is required for each antenna of each array antenna. There is a problem that the power supply section is required, the apparatus configuration is large, and the weight is increased.

  In order to estimate the arrival wave, a wide area is to be investigated, so it is desirable to install an arrival wave estimation device on the vehicle and perform real-time processing while traveling, and to change the arrival direction of the arrival wave for multiple frequencies, It is necessary to mount on the vehicle a radio device including an array antenna corresponding to each frequency to be measured and a power feeding unit that performs signal processing of the array antenna.

  In order to mount the arrival wave estimation device on a vehicle, it is desirable that the wireless device including the array antenna is small. However, the arrival wave estimation device corresponding to a plurality of frequencies requires a large number of power feeding units together with a large number of antennas, and the device configuration. Therefore, an arrival wave estimation device that can be shared for a plurality of frequencies is demanded.

  Therefore, the present invention has been made to solve the conventional problems and to provide a multi-frequency shared antenna device that can be shared for a plurality of frequencies, and to arrange the array antennas constituting the multi-frequency shared antenna device. It is another object of the present invention to provide an arrival direction estimation device that can measure the arrival directions of arrival waves having a plurality of frequencies with a single device.

  The present invention prepares an array antenna composed of a plurality of antennas for different transmission / reception frequencies, and arranges the array antennas of these frequencies so as to have a predetermined positional relationship, so that one antenna is apparently arranged in a plurality. A multi-frequency shared antenna device shared with respect to the frequency is configured, and an arrival direction estimating device is configured using the multi-frequency shared antenna device.

  In the array antenna arrangement method according to the present invention, array antennas composed of a plurality of antennas are arranged in layers for different transmission / reception frequencies, and antennas in positions corresponding to each layer are connected in series and connected in series. One end of the antenna is connected to each feeder.

  According to the aspect of the array antenna arrangement method of the present invention, each array antenna is arranged in a layer form to apparently constitute one antenna, and antennas in a positional relationship corresponding to each other in each layer are connected in series. By connecting one end of the connected antenna to each power feeding unit, the power feeding unit can be shared for a plurality of frequencies, and the configuration of the wireless device can be simplified.

  The layer order of array antennas arranged in layers can be the order of transmission and reception frequencies. In the first arrangement form in this order of transmission / reception frequency, an array antenna having a low transmission / reception frequency is arranged in an upper layer, an array antenna having a high transmission / reception frequency is arranged in a lower layer, and corresponding antennas in adjacent layers above and below are connected to each other. The arrangement is such that the antenna of the lowermost array antenna is connected to the feeding section.

  The connection between the antennas can be made through a low-pass filter that passes the transmission / reception frequency of the upper-layer array antenna. By providing a low-pass filter between the antennas, at the time of reception, the high-frequency component contained in the signal received on the array antenna side with a low transmission / reception frequency is removed by the low-pass filter, and the low transmission / reception frequency component to be measured is placed on the power feeding unit side. Can send.

  In the second arrangement form in order of transmission / reception frequency, an array antenna having a high transmission / reception frequency is arranged above, an array antenna having a low transmission / reception frequency is arranged below, and corresponding antennas in adjacent layers above and below are connected. The arrangement is such that the antenna of the lowermost array antenna is connected to the feeder.

  The connection between the antennas can be made by a connection line such as a microstrip line. A connection line such as a microstrip line connecting the antennas can be formed on a substrate supporting the antenna in each layer, and a low-pass filter can be formed on the substrate.

  The array antenna of each layer can be formed into a layered rectangular array antenna by arranging a plurality of antennas in a rectangular shape with the length of the half wavelength of the transmission / reception frequency of the array antenna as the array interval.

  Moreover, the array antenna of each layer can constitute a layered circular array antenna by arranging a plurality of antennas in a circular shape with the length of the half wavelength of the transmission / reception frequency of the array antenna as the array interval.

  An aspect of the multi-frequency shared antenna device of the present invention includes a plurality of array antennas composed of a plurality of antennas, a connection unit that connects the antennas of the plurality of array antennas, and a power feeding unit that transmits and receives the antennas. The plurality of array antennas are arranged in layers for each transmission / reception frequency, and transmit and receive at different frequencies by sharing the same power feeding unit.

  According to the aspect of the multi-frequency shared antenna apparatus of the present invention, each array antenna is arranged in layers to form an apparently one antenna, and the antennas connected to each other in the corresponding positions in each layer are connected by the connecting portion. By supplying power from the power supply unit to one end of the antenna, the power supply unit can be shared for a plurality of frequencies, and the configuration of the wireless device can be simplified.

  The layer order of array antennas arranged in layers can be the order of transmission and reception frequencies. In the first arrangement form in this order of transmission / reception frequency, the array antenna has an array antenna having a low transmission / reception frequency arranged in an upper layer and an array antenna having a high transmission / reception frequency arranged in a lower layer. The connecting portion connects the corresponding antennas in the upper and lower adjacent layers via a low-pass filter that passes the transmission / reception frequency of the upper-layer array antenna. The feeding unit is connected to the antenna of the lowermost array antenna.

  By providing a low-pass filter between the antennas, the multi-frequency antenna device removes the high-frequency component contained in the signal received on the array antenna side of the low transmission / reception frequency at the time of reception by using the low-pass filter, and the low transmission / reception frequency component to be measured Can be sent to the power feeding unit side.

  In the second arrangement form in order of transmission / reception frequency, the array antenna has an array antenna with a high transmission / reception frequency arranged in the upper layer and an array antenna with a low transmission / reception frequency arranged in the lower layer. The feeding unit is connected to the antenna of the lowermost array antenna.

  In the multi-frequency shared antenna apparatus, the antennas can be connected by a connection line such as a microstrip line. A connection line such as a microstrip line connecting the antennas can be formed on a substrate supporting the antenna in each layer, and a low-pass filter can be formed on the substrate.

  In the multi-frequency antenna device, the array antennas of each layer constitute a layered rectangular array antenna by arranging a plurality of antennas in a rectangular shape with the length of half wavelength of the transmission / reception frequency of the array antenna as an array interval. Further, by arranging a plurality of antennas in a circular shape with the length of a half wavelength of the transmission / reception frequency of the array antenna as an array interval, a layered circular array antenna can be configured.

  An aspect of an arrival direction estimation device according to the present invention includes a multi-frequency shared antenna device, and an arrival wave direction estimation unit that estimates the direction of an incoming wave based on incoming waves received by a plurality of antennas included in the multi-frequency shared antenna device. It is set as the structure provided.

  An arrival wave direction estimation part estimates an arrival direction about the arrival wave of any one frequency in the frequency which each array antenna which the multiple array antenna with which a multi-frequency shared antenna apparatus is equipped receives is made into a measuring object.

  According to the multi-frequency shared antenna apparatus of the present invention, it can be shared for a plurality of frequencies. According to the array antenna arrangement method of the present invention, the array antenna used in the multi-frequency shared antenna apparatus of the present invention is configured. can do. Moreover, according to the arrival direction estimation apparatus of the present invention, the arrival directions of arrival waves having a plurality of frequencies can be measured with one apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The array antenna arrangement method of the present invention and the multi-frequency shared antenna apparatus of the present invention configured by this array antenna layout method will be described with reference to FIGS. 1 to 9, and the multi-frequency shared antenna device of the present invention will be described with reference to FIG. A direction-of-arrival estimation apparatus constituted by an antenna apparatus will be described.

  First, a rectangular array antenna will be described with reference to FIGS. 1 to 5, and a circular array antenna will be described with reference to FIGS. 6 to 9.

  FIG. 1 is an example of a rectangular array antenna configured by arranging antennas in a rectangular shape. The rectangular array antenna shown here is an example that transmits and receives three frequencies of 900 MHz, 1.5 GHz, and 2.0 GHz. The multi-frequency shared antenna apparatus is configured by layering array antennas 1, 2, and 3 of each frequency in layers. Here, the array antenna of each layer shows an example of 16 elements each having four antennas arranged on one side.

  FIGS. 1A and 1B show the layered arrangement of a first array antenna 1 for 900 MHz, a second array antenna 2 for 1.5 GHz, and a third array antenna 3 for 2.0 GHz below or above. The state seen from the stacking direction is shown. 1A schematically shows a layered arrangement, and FIG. 1B shows an antenna arrangement constituting each array antenna.

  In the example shown in FIG. 1, the first array antenna 1 has 16 elements of antennas 1a to 1p (indicated by hatching in the figure) arranged on each lattice point, and the second array antenna 2 has antennas 2a to 2p (in the figure). Are arranged on each lattice point, and the third array antenna 3 has 16 elements of antennas 3a to 3p (shown by oblique lines intersecting the x and y directions in the figure). Arranged on each grid point. The interval between the lattice points in the x and y directions is the length of the half wavelength of each frequency.

  In the array antennas 1 to 3 arranged in each layer, each antenna (for example, the antenna 1a, the antenna 2a, the antenna 3a,..., The antenna 1p, the antenna 2p, and the antenna 3p) at the same lattice point position is a microstrip line or the like. They are connected in series by connecting lines. For example, the antenna 1p and the antenna 2p are connected by a connection line 4p1, and the antenna 2p and the antenna 3p are connected by a connection line 4p2.

  FIG. 1 (c) shows the array antennas 1, 2, and 3 of each layer separately. The antennas of the respective layers at the same lattice point position are connected in series by a connection line, and one end thereof is connected to each part 5 a to 5 p of the power feeding part 5. Thereby, each antenna connected in series shares a common power feeding unit. For example, the antennas 1p, 2p, and 3p at the same lattice point share the power feeding unit 5p (connected by a solid line in FIG. 1 (c)), and the antennas 1l, 2l, and 3l share the power feeding unit 5l. (Connected by a broken line in FIG. 1C).

  In the conventional configuration shown in FIG. 12, each frequency array antenna requires a power feeding unit individually, whereas in the configuration of the present invention, the power feeding unit is shared with a plurality of frequency array antennas. Thus, the number of power feeding units can be reduced.

  FIG. 2 is a schematic perspective view for explaining a layered structure of the rectangular array antenna and a method of arranging the rectangular array antenna in the multi-frequency shared antenna apparatus of the present invention.

  The array antenna of each layer of the multi-frequency shared antenna apparatus of the present invention can be arranged in order of frequency.

  FIGS. 2A and 2B show a configuration example in which a low-frequency array antenna is arranged in the upper layer and a high-frequency array antenna is arranged in the lower layer, and FIGS. 2C and 2D show the high-frequency array antenna. A configuration example is shown in which an array antenna is arranged in the upper layer and a low-frequency array antenna is arranged in the lower layer. 2A and 2C show only a part of the plurality of antennas included in each of the array antennas 1, 2 and 3 in order to show the connection state of the antennas between the layers. 2 (b) and 2 (d) omit the connections between the array antennas 1, 2, and 3 in order to show the antenna arrangement state in each layer.

  2B and 2D, in the array antennas 1 to 3 of each layer, the antennas 1a to 1p are supported on the substrate of the array antenna 1, and the antennas 2a to 2p are supported on the substrate of the array antenna 2. The antennas 3 a to 3 p are supported on the substrate of the array antenna 3. Each substrate is disposed adjacent to the upper end of the antenna of the array antenna below the substrate. For example, in the arrangement example of FIG. 2A, the substrate of the array antenna 1 is adjacent to the upper end of the antenna of the lower array antenna 2, and the substrate of the array antenna 2 is adjacent to the upper end of the antenna of the lower array antenna 3.

  On this board | substrate, the connection line which connects the antenna of each layer can be provided. For example, in the arrangement example of FIG. 2A, a connection line 4d1 is provided on the substrate of the array antenna 1, and the connection line 4d1 is connected to the upper end of the antenna 2d of the lower array antenna 2. Further, a connection line 4d2 is provided on the substrate of the array antenna 2, and the connection line 4d2 is connected to the upper end of the antenna 3d of the lower array antenna 3. Each antenna in the lowermost layer is connected to the power feeding unit 5.

  The above configuration can be similarly applied to a configuration example in which a high frequency array antenna is arranged in an upper layer and a low frequency array antenna is arranged in a lower layer, as shown in FIGS.

  In addition, the space | interval between the board | substrates of each layer can also make a predetermined space | interval between a board | substrate bottom part and an antenna upper end besides contacting a board | substrate bottom part and an antenna upper end. When the bottom of the substrate and the upper end of the antenna are brought into contact with each other, the height of the multi-frequency antenna device can be reduced. The antenna including each substrate can be held by a fixing means (not shown).

  The arrangement of the antennas of the array antennas in each layer will be described in more detail with reference to FIGS. FIG. 3 shows a configuration example in which a low frequency array antenna is arranged in the upper layer and a high frequency array antenna is arranged in the lower layer. FIG. 4 shows a configuration in which the high frequency array antenna is arranged in the upper layer and the low frequency array antenna is arranged in the lower layer. It is the example of a structure arrange | positioned. Here, three frequencies of 900 MHz, 1.5 GHz, and 2.0 GHz are shown as target frequencies.

  In FIG. 3, the connection line 4d1 provided on the substrate of the array antenna 1 is connected to the upper end of the antenna 2d of the lower array antenna 2, and the connection line 4d2 provided on the substrate of the array antenna 2 is the lower array antenna. By connecting to the upper end of the third antenna 3d, the antennas are connected in series. The antenna in the lowermost layer is connected to the power feeding unit 5, whereby the antennas 1 d, 2 d, 3 d connected in series share the power feeding unit. In addition to the antennas 1c, 1h, 1g,..., 3c, 3h, 3g shown in FIG.

  The connection lines 4d1, 4d2,... Can be provided by forming microstrip lines on the substrate. Further, a filter (low-pass filter) can be provided in the connection line.

  FIG. 3B shows a configuration in which antennas between layers are connected by microstrip lines. In the configuration example in which the low-frequency array antenna is arranged in the upper layer and the high-frequency array antenna is arranged in the lower layer, the antennas in each layer are connected by a microstrip line.

  When an incoming wave having a frequency of 900 MHz, 1.5 GHz, and 2.0 GHz arrives, the 900 MHz antenna receives a 900 MHz frequency signal, the 1.5 GHz antenna receives a 1.5 GHz frequency signal, and 2 The 0.0 GHz antenna receives the 2.0 GHz frequency signal and sends it to the power feeding unit.

  Further, when a 900 MHz incoming wave is received by a 900 MHz antenna, a 1.5 GHz or 2.0 GHz incoming wave may be included in addition to the 900 MHz incoming wave. At this time, since the 1.5 GHz or 2.0 GHz signal is transmitted from the 1.5 GHz antenna or the 2.0 GHz antenna before reaching the power feeding unit, the power feeding unit receives it during the measurement of the 900 MHz incoming wave. The intensity of incoming waves at 1.5 GHz and 2.0 GHz is reduced.

  The same applies to the received signal of the 1.5 GHz antenna, and an incoming wave of 2.0 GHz may be included in addition to the incoming wave of 1.5 GHz. At this time, since the 2.0 GHz signal is transmitted from the 2.0 GHz antenna before reaching the power feeding unit, the arrival of 1.5 GHz or 2.0 GHz reaching the power feeding unit during the measurement of the 1.5 GHz incoming wave. Wave intensity is reduced.

  In addition, a filter can be provided on the connection line. As shown in FIG. 3, in a configuration in which a low-frequency array antenna is arranged in the upper layer and a high-frequency array antenna is arranged in the lower layer, a low-pass filter is provided.

  This low-pass filter is a filter that passes the low transmission / reception frequency of the upper layer array antenna. This low-pass filter sends the low-frequency signal component received by the upper-layer array antenna to the feeding unit side as it is, blocks off the high-frequency signal component received by the upper-layer array antenna, and inputs it to the feeding unit side. Reduce. The connection line itself can be provided with a filter function by adjusting the length of the connection line.

  In FIG. 4, the connection line 4d1 provided on the substrate of the array antenna 2 is connected to the upper end of the antenna 1d of the lower array antenna 1, and the connection line 4d2 provided on the substrate of the array antenna 3 is the lower array antenna. Each antenna is connected in series by connecting to the upper end of the second antenna 2d. The lowermost antenna 1d is connected to the power feeding unit 5, and thus the antennas 1d, 2d, and 3d connected in series share the power feeding unit. In addition to the antennas 1c, 1h, 1g,..., 3c, 3h, 3g shown in FIG.

  The connection lines 4d1, 4d2,... Can be provided by forming microstrip lines on the substrate.

  FIG. 4B shows a configuration in which antennas between layers are connected by microstrip lines. In the configuration example in which the high-frequency array antenna is arranged in the upper layer and the low-frequency array antenna is arranged in the lower layer, the antennas in each layer are connected by a microstrip line.

  When an incoming wave having a frequency of 900 MHz, 1.5 GHz, and 2.0 GHz arrives, the 900 MHz antenna receives a 900 MHz frequency signal, the 1.5 GHz antenna receives a 1.5 GHz frequency signal, and 2 The 0.0 GHz antenna receives the 2.0 GHz frequency signal and sends it to the power feeding unit.

  In addition, when the 2.0 GHz antenna receives an incoming wave of 2.0 GHz, an incoming wave of 1.5 GHz or 900 MHz may be included in addition to the incoming wave of 2.0 GHz. At this time, since the 1.5 GHz or 900 MHz signal is transmitted from the 1.5 GHz antenna or the 900 MHz antenna before reaching the power supply unit, the signal reaches the power supply unit during measurement of the 2.0 GHz incoming wave. The intensity of incoming waves at 5 GHz and 900 MHz is reduced.

  The same applies to the reception signal of the 1.5 GHz antenna, and when the 900 MHz arrival wave is included in addition to the 1.5 GHz arrival wave, the 900 MHz signal is used for the 900 MHz signal before reaching the power feeding unit. Therefore, the intensity of the 900 MHz incoming wave received by the power feeding unit during the measurement of the 1.5 GHz incoming wave is reduced.

  FIG. 5 is a diagram of each layer as viewed from the stacking direction (vertical direction), and shows a horizontal distance relationship between the antennas of the array antenna of each layer. In FIG. 5, when the horizontal distance between the antennas having the same positional relationship in each layer is viewed, the antenna 1d included in the first array antenna 1, the antenna 2d included in the second array antenna 2, and the third array The respective distances between the antenna 3 and the antenna 3d are 14.1 cm and 5.30 cm, respectively. Here, when the frequencies of the first array antenna 1, the second array antenna 2, and the third array antenna 3 are 900 MHz, 1.5 GHz, and 2.0 GHz, respectively, each half wavelength (λ / 2) is respectively These lengths are 16.7 cm, 10.0 cm, and 7.5 cm, and the length of the half wavelength is used as the interval of the lattice arrangement.

  The distances between the antenna 1h included in the first array antenna 1, the antenna 2h included in the second array antenna 2, and the antenna 3h included in the third array antenna 3 are 10.5 cm and 3 respectively. Each distance between the antenna 1g included in the first array antenna 1, the antenna 2g included in the second array antenna 2, and the antenna 3g included in the third array antenna 3 is 4.95 cm. 71 cm and 1.76 cm.

  Next, a circular array antenna will be described.

  FIG. 6 is an example of a circular array antenna configured by arranging antennas in a circular shape. The circular array antenna shown here is an example of transmitting and receiving three frequencies of 900 MHz, 1.5 GHz, and 2.0 GHz. The multi-frequency shared antenna apparatus is configured by layering array antennas 1, 2, and 3 of each frequency in layers. Here, the array antenna of each layer is shown as an example of eight elements each having eight antennas arranged on the circumference.

  6A and 6B show the layered arrangement of the first array antenna 11 for 900 MHz, the second array antenna 12 for 1.5 GHz, and the third array antenna 13 for 2.0 GHz below or above. The state seen from the stacking direction is shown. 6A schematically shows a layered arrangement, and FIG. 6B shows an antenna arrangement constituting each array antenna.

  In the example shown in FIG. 6, the first array antenna 11 has eight elements 11a to 11h (indicated by hatching in the figure) arranged at equal intervals on the circumference, and the second array antenna 12 has antennas 12a to 12h ( Eight elements (shown by diagonal lines crossing diagonally in the figure) are arranged at equal intervals on the circumference, and the third array antenna 13 is antennas 13a to 13h (shown by diagonal lines crossing the x and y directions in the figure). The eight elements are arranged at equal intervals on the circumference. The interval between adjacent antennas on each circumference is the length of a half wavelength of each frequency.

  In the array antennas 11 to 13 arranged in each layer, each antenna (for example, the antenna 11a, the antenna 12a, the antenna 13a,..., The antenna 11h, the antenna 12h, and the antenna 13h) at the same angular position on the circumference is a microstrip. They are connected in series by connecting lines such as lines. For example, the antenna 11a and the antenna 12a are connected by a connection line 4a1, the antenna 12a and the antenna 13a are connected by a connection line 4a2, and the antenna 11h and the antenna 12h are connected by a connection line 4h1. The antenna 12h and the antenna 13h are connected by a connection line 4h2.

  FIG. 6C shows the array antennas 1, 2 and 3 of each layer separately. The antennas of the respective layers at the same angular position on the circumference are connected in series by a connecting line, and one end thereof is connected to each part 15 a to 15 h of the power feeding part 5. Thereby, each antenna connected in series shares a common power feeding unit. For example, the antennas 11h, 12h, and 13h at the same angular position share the feeding unit 15h (connected by the solid line in FIG. 6C), and the antennas 11a, 12a, and 13a share the feeding unit 15a. (Connected by a broken line in FIG. 6C).

  In the conventional configuration, the array antenna of each frequency requires a power feeding unit individually, whereas in the configuration of the present invention, the number of power feeding units is shared by sharing the power feeding unit for the array antennas of a plurality of frequencies. Can be reduced.

  FIG. 7 is a schematic perspective view for explaining a layered configuration of a circular array antenna and a method for arranging the circular array antenna in the multi-frequency shared antenna apparatus of the present invention.

  The array antenna of each layer of the multi-frequency shared antenna apparatus of the present invention can be arranged in order of frequency.

  FIGS. 7A and 7B show a configuration example in which a low-frequency array antenna is arranged in the upper layer and a high-frequency array antenna is arranged in the lower layer, and FIGS. 7C and 7D show the high-frequency array antenna. A configuration example is shown in which an array antenna is arranged in the upper layer and a low-frequency array antenna is arranged in the lower layer. FIGS. 7A and 7C show only a part of the plurality of antennas included in each of the array antennas 11, 12, and 13 in order to show the connection state of the antennas between the layers. 7 (b) and 7 (d) omit the connection between the array antennas 11, 12, and 13 in order to show the antenna arrangement state in each layer.

  7B and 7D, in the array antennas 11 to 13 of each layer, the antennas 11a to 11h are supported on the substrate of the array antenna 11, and the antennas 12a to 12h are supported on the substrate of the array antenna 12. The antennas 13 a to 13 h are supported on the substrate of the array antenna 13. Each substrate is disposed adjacent to the upper end of the antenna of the array antenna below the substrate. For example, in the arrangement example of FIG. 7A, the substrate of the array antenna 11 is adjacent to the upper end of the antenna of the lower array antenna 12, and the substrate of the array antenna 12 is adjacent to the upper end of the antenna of the lower array antenna 13.

  On this board | substrate, the connection line which connects the antenna of each layer can be provided. For example, in the arrangement example of FIG. 7A, a connection line 14-1 is provided on the substrate of the array antenna 11, and the connection line 14-1 connects to the upper end of the antenna of the lower array antenna 12. Is called. A connection line 14-2 is provided on the substrate of the array antenna 2, and the connection line 14-2 is connected to the upper end of the antenna 13 of the lower array antenna 3. Each antenna in the lowermost layer is connected to the power feeding unit 15.

  As shown in FIGS. 7C and 7D, the above configuration can be similarly applied to a configuration example in which a high frequency array antenna is arranged in the upper layer and a low frequency array antenna is arranged in the lower layer.

  In addition, the space | interval between the board | substrates of each layer can also make a predetermined space | interval between a board | substrate bottom part and an antenna upper end besides contacting a board | substrate bottom part and an antenna upper end. When the bottom of the substrate and the upper end of the antenna are brought into contact with each other, the height of the multi-frequency antenna device can be reduced. The antenna including each substrate can be held by a fixing means (not shown).

  In addition, the distance between adjacent antennas and the radius of the circle in each layer of the circular array antenna are, for example, 16.7 cm and 42.7 cm of half-wavelength in the first array antenna 11 for 900 MHz, and 1.5 GHz. In the second array antenna 12 for use, the half wavelength lengths are 10.0 cm and 25.6 cm, and in the 2.0 GHz third array antenna 13, the half wavelength lengths are 7.5 cm and 19.2 cm. .

  8 and 9 are schematic diagrams for explaining a configuration example of a circular array antenna. FIG. 8 is a configuration example in which the antennas of the respective layers are connected by the connection lines provided on the respective substrates as described above, and FIG. 9 is a configuration example in which the antennas of the respective layers arranged obliquely are arranged in a straight line by the connection lines. . 8 and 9 show examples of eight elements.

  In FIG. 8, the multi-frequency shared antenna apparatus is configured by arranging a plurality of antennas shown in FIG. 8A as a unit and arranging them at an equal angle on the circumference. Each unit of the antenna shown in FIG. 8 (a) has a configuration in which the antennas (11, 12, 13) of the respective layers displaced in the vertical direction are connected in series at the connection portion 16 in the horizontal direction. Either a configuration in which the antenna is arranged in the upper layer (FIG. 8B) or a configuration in which the low-frequency antenna is arranged in the upper layer (FIG. 8C) can be used. The details of the configuration shown in FIG. 8 are as shown in FIGS.

  In FIG. 9, the multi-frequency shared antenna apparatus is configured by arranging a plurality of antennas shown in FIG. 9A as a unit and arranging them at an equal angle on the circumference. Each unit of the antenna shown in FIG. 9A is configured by arranging the antennas of each layer in a straight line in the vertical direction and connecting these antennas at a connecting portion to form a straight line. The distance between the antennas in each layer is set to a half wavelength by tilting the antenna unit formed by arranging the antennas in a straight line.

  FIG. 9A shows one structural unit of a plurality of antennas, and a plurality of antennas (11, 12, 13) are connected in a straight line at the connection portion 17.

  FIG. 9B is a configuration example in which this structural unit is inclined at an equal angle on the circumference so that the high-frequency antenna is an upper layer, and FIG. This is a configuration example in which a low frequency antenna is tilted so as to be an upper layer and arranged at an equal angle on the circumference. Note that the length and the inclination angle of the connection unit 17 of the structural unit are set so that the distance between the antennas constituting each layer becomes a half wavelength length determined by the frequency to be measured.

  In addition, the example of the dimension of the distance between adjacent antennas and the radius of a circle in each layer of the circular array antenna is 16.7 cm and 42.7 cm of the half-wavelength in the first array antenna 11 for 900 MHz. The second array antenna 12 for 5 GHz has a half-wavelength of 10.0 cm and 25.6 cm, and the third array antenna 13 for 2.0 GHz has a half-wavelength of 7.5 cm and 19.2 cm. is there.

  FIG. 10 is a schematic diagram for explaining a configuration example of the arrival direction estimation apparatus. Here, an example in which the arrival direction of an incoming wave is estimated by the MUSIC method will be described. The arrival direction estimation device 20 includes an array antenna 30 that receives an arrival wave, an arrival wave direction estimation unit 60 that estimates the direction of the arrival wave from the received signal, and an arrival direction display unit 70 that displays the estimated arrival direction.

  The array antenna 30 includes a plurality of antennas 31 that receive incoming waves, and each antenna 31 is connected to the receiving unit 41 of the power feeding unit 40. The receiving unit 41 performs pre-signal processing necessary for estimating the direction of the incoming wave with respect to the signal received by the antenna 31.

  The arrival wave direction estimation unit 60 estimates the direction of the arrival wave based on the received signal. In the case of the MUSIC method, for example, a correlation matrix calculator that calculates a correlation matrix of input signal vectors obtained by collecting the baseband signals from the receiving units 41, and eigenvalues and eigenvectors are calculated by eigenvalue decomposition of the correlation matrix. An eigenvalue / eigenvector calculator, an incoming wave number criterion calculation calculator that calculates an incoming wave number criterion using eigenvalues, an incoming wave number estimator that detects the minimum value of the incoming wave number criterion and estimates the incoming wave number, A noise subspace eigenvector extractor that extracts a noise subspace eigenvector from eigenvectors from the wave number estimation result, a MUSIC spectrum calculator that calculates an angular distribution (MUSIC spectrum) of an incoming wave using the noise subspace eigenvector, and a MUSIC spectrum Direction-of-arrival estimator that detects the local maximum value and estimates the direction of arrival? Constructed. The arrival direction estimated by the arrival wave direction estimation unit 60 is displayed by the arrival direction display unit 70.

  The present invention can be applied to investigation of reception status of radio waves, installation adjustment of base stations, detection of unauthorized boosters, and the like.

It is a figure for demonstrating an example of the rectangular array antenna comprised by arranging the antenna of this invention in the rectangular shape. It is a schematic perspective view for demonstrating the layered structure of a rectangular array antenna, and the arrangement | positioning method of a rectangular array antenna in the multifrequency shared antenna apparatus of this invention. It is a figure for demonstrating the example of arrangement | positioning of the antenna of the array antenna of each layer of the multifrequency shared antenna apparatus of this invention. It is a figure for demonstrating the other example of arrangement | positioning of the antenna of the array antenna of each layer of the multifrequency shared antenna apparatus of this invention. It is the figure which looked at each layer of the multi-frequency common antenna device of the present invention from the lamination direction (vertical direction). It is a figure for demonstrating an example of the circular array antenna comprised by arranging the antenna of this invention in circular shape. It is a schematic perspective view for demonstrating the layered structure of a circular array antenna, and the arrangement | positioning method of a circular array antenna in the multifrequency shared antenna apparatus of this invention. It is the schematic for demonstrating the structural example of the circular array antenna of this invention. It is the schematic for demonstrating the structural example of the circular array antenna of this invention. It is a figure for demonstrating the arrival direction estimation apparatus comprised by the multi-frequency common antenna apparatus of invention. It is the schematic for demonstrating arrangement | positioning of each antenna of an array antenna. It is the schematic for demonstrating the relationship between the antenna and electric power feeding part in the conventional incoming wave estimation apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st array antenna 1a-1p Antenna 2 2nd array antenna 2a-2p Antenna 3 3rd array antenna 3a-3p Antenna 4, 4d1, 4d2, 4h1, 4h2, 4-1, 4-2 Connection lines 5, 5a 5p Feeder 11 First array antenna 11a to 11h Antenna 12 Second array antenna 12a to 12h Antenna 13 Third array antenna 13a to 13h Antennas 14a1, 14a2, 14h1, 14h2, 14-1, 14-2 Connection lines 15, 15a ~ 15h Feeding part 16, 17 connecting part
DESCRIPTION OF SYMBOLS 20 Arrival direction estimation apparatus 30 Array antenna 31 Antenna 40 Feed part 41 Receiving part 50 Multifrequency shared antenna apparatus 60 Arrival wave direction estimation part 70 Arrival wave direction comparison part

Claims (18)

Arranging array antennas composed of multiple antennas in layers for different transmission and reception frequencies,
An array antenna arranging method, wherein antennas at positions corresponding to each layer are connected in series, and one end of the series-connected antennas is connected to each feeding portion.   2. The array antenna arrangement method according to claim 1, wherein the layer order of the array antenna is the order of transmission and reception frequencies.   An array antenna with a low transmission / reception frequency is arranged in the upper layer, an array antenna with a high transmission / reception frequency is arranged in the lower layer, the corresponding antennas in adjacent layers above and below are connected, and the antenna of the array antenna at the lowest layer is connected to the feeder The array antenna arranging method according to claim 2, wherein: 4. The array antenna arrangement method according to claim 3, wherein the antennas corresponding to the upper and lower adjacent layers are connected via a low-pass filter that passes the transmission / reception frequency of the upper layer array antenna.   An array antenna with a high transmission / reception frequency is arranged above, an array antenna with a low transmission / reception frequency is arranged below, and the corresponding antennas on the upper and lower adjacent layers are connected, and the antenna of the array antenna on the lowest layer is connected to the feeder The array antenna arranging method according to claim 2, wherein:   6. The array antenna arrangement method according to claim 1, wherein the antennas are connected by a microstrip line.   7. The array antenna of each layer according to claim 1, wherein a plurality of antennas are arranged in a rectangular shape with a length of a half wavelength of a transmission / reception frequency of the array antenna as an array interval. 8. Arrangement method of array antenna.   7. The array antenna of each layer according to claim 1, wherein a plurality of antennas are arranged in a circular shape with a length of a half wavelength of a transmission / reception frequency of the array antenna as an array interval. 8. Arrangement method of array antenna. A plurality of array antennas composed of a plurality of antennas;
A connection for connecting the antennas of the plurality of array antennas;
It has a power feeding part that transmits and receives to the antenna,
The plurality of array antennas are arranged in layers for each transmission / reception frequency, and transmit and receive at different frequencies by sharing the same power supply unit.   The multi-frequency shared antenna apparatus according to claim 9, wherein the layer order of the array antenna is the order of transmission and reception frequencies. The array antenna has a low transmission / reception frequency array antenna arranged in the upper layer, a high transmission / reception frequency array antenna arranged in the lower layer,
The connection portion connects between corresponding antennas of adjacent layers in the upper and lower sides,
The multi-frequency shared antenna apparatus according to claim 9, wherein the power feeding unit is connected to an antenna of a lowermost array antenna.   12. The multi-frequency shared antenna apparatus according to claim 11, wherein the connection unit connects corresponding antennas in upper and lower adjacent layers via a low-pass filter that passes transmission / reception frequencies of an upper-layer array antenna. The array antenna has a high transmission / reception frequency array antenna arranged in the upper layer, and a low transmission / reception frequency array antenna arranged in the lower layer,
The connection portion connects between corresponding antennas of adjacent layers in the upper and lower sides,
The multi-frequency shared antenna apparatus according to claim 9, wherein the power feeding unit is connected to an antenna of a lowermost array antenna.   The multi-frequency shared antenna apparatus according to any one of claims 9 to 13, wherein the connection unit includes a microstrip line that connects antennas.   15. The array antenna of each layer includes a plurality of antennas arranged in a rectangular shape with the length of a half wavelength of the transmission / reception frequency of the array antenna as an array interval. Multi-frequency antenna system.   The array antenna of each layer is provided with a plurality of antennas arranged in a circular shape with the length of a half wavelength of the transmission / reception frequency of the array antenna as an array interval. Multi-frequency antenna system. The multi-frequency shared antenna device according to any one of claims 9 to 16,
An arrival direction estimation apparatus, comprising: an arrival wave direction estimation unit that estimates an arrival wave direction based on arrival waves received by a plurality of antennas included in the multi-frequency shared antenna apparatus.   The arrival wave direction estimation unit estimates an arrival direction of an arrival wave of any one of frequencies to be measured by each array antenna received by a plurality of array antennas included in the multi-frequency shared antenna device. The direction-of-arrival estimation apparatus according to claim 17, wherein the direction-of-arrival estimation apparatus is characterized.

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