JP2006270847A - Antenna device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna device capable of extending beam width after being synthesized until the same degree of a sub-antenna while increasing antenna gain up to several times of the sub-antenna. <P>SOLUTION: The device comprises a plurality of reception sub-antennas 1 having a directivity beam dispersed on the ground, an integrated beam controller 2 for controlling a beam orientation of the plurality of the reception sub-antennas 1, receivers 3 for each receiving a signal via one of the reception sub-antennas 1, and a receiving fixed value beam forming processor 4. The processor 4 has a covariance matrix calculating unit 5 for calculating covariance matrix of output signals of the receivers 3, a maximum fixed vector calculating unit 6 for calculating a fixed vector corresponding to the maximum fixed value of the covariance matrix, complex multiplying units 7 for each multiplying the fixed vector as a weight by the output signals of respective receivers 3, and a summation calculating unit 8 for calculating and outputting a summation of the output signals of each of the receivers 3 after being multiplied by the weight. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an array antenna apparatus for radar, sonar or communication that receives or transmits radio waves and sound waves using a directional beam.

  In general, it is conceivable to increase the antenna aperture diameter in order to increase the gain of the array antenna, but this is not preferable because the apparatus becomes large-scale. Thus, for example, there is a technique disclosed in Non-Patent Document 1 as a technique for avoiding the increase in scale of the antenna device.

  In this non-patent document 1, a high gain equivalent to that received by a receiving antenna having a large aperture is obtained by coherently synthesizing received signals from a plurality of small antennas distributed at intervals. . A plurality of small antennas arranged in a distributed manner are hereinafter referred to as sub-antennas, and an antenna apparatus that is an equivalent large aperture antenna by electrically synthesizing the received signals of these sub-antennas is referred to as a distributed aperture antenna in the following description. I will call it.

  On the other hand, in the field of adaptive antennas, various techniques as shown in Non-Patent Document 2 have been proposed as techniques for adaptively forming a beam using received signals of an array element and effectively amplifying a required signal and suppressing unnecessary interference waves. Beam forming algorithms are known. It is also known that many of these algorithms can be applied to arbitrary element arrangements.

R. C. Heimiller, J.M. E. Belyaa and P.M. G. Tomlinsonr, “Distributed array radar,” IEEE Transactions on Aerospace and Electronic Systems, Vol. 19, no. 6, pp. 831-839, Nov. 1983. H. Krim and M.M. Viberg, “Two decades of array processing research: the parametric approach,” IEEE Signal Processing Magazine, Vol. 13, no. 4, pp. 67-94, July 1996.

In a conventional distributed aperture antenna represented by Non-Patent Document 1, a received signal of a sub-antenna is synthesized by a normal beamformer method as described in Non-Patent Document 2, thereby generating a high-gain sharp reception beam. It can be formed, and it is shown that the combined reception antenna pattern has the following characteristics.
(1) Increase in antenna gain When the number of sub-antennas is K, the combined reception gain is about K times the reception gain of each sub-antenna.
(2) Reduction of beam width If the length between both ends of the sub-antenna arrangement is M times the sub-antenna opening length, the combined received beam width is about 1 / M of the received beam width of each sub-antenna. .
As described above, when the distributed aperture antenna is used, the overall reception sensitivity of the system is improved by increasing the antenna gain, and a great effect can be obtained, for example, the detection performance in the radar can be improved.

  However, this reduction in beam width causes a disadvantage that the area covering the space is reduced at the same time. For example, when applied to search radar, the spatial search efficiency is significantly deteriorated. Therefore, the conventional distributed aperture antenna has a problem that the reception beam width after synthesis cannot be expanded to the same extent as that of the sub antenna while increasing the reception antenna gain to about K times that of the sub antenna.

  Further, Non-Patent Document 1 does not disclose a technique for combining the transmission signals of the sub-antennas when the distributed aperture antenna is used for transmission. That is, as in the case of reception, the concept of a distributed aperture antenna for transmission having a wide transmission beam width and a large transmission beam width has not been disclosed at all.

  Note that a general adaptive antenna adaptively forms a beam so as to extract only a desired signal by suppressing unnecessary interference waves from signals received by a plurality of element antennas, mobile communication, acoustic imaging, It is used in the fields of radar, sonar, etc., and its beam forming algorithms have been extensively studied.

  Among the adaptive antennas, as a conventional technique for forming a beam using eigenvalue expansion, there is a technique for obtaining a weight directly from calculation of an eigenvalue of a correlation matrix of an input signal. This technology is noted for its theoretical clarity and good performance. In the minimum norm method and the MUSIC method, which are known as this typical technique and disclosed in Non-Patent Document 2, the signal arrival direction is estimated with high accuracy using the minimum eigenvalue of the correlation matrix. Therefore, it is impossible to increase the combined beam width to the same level as that of the sub antenna while increasing the gain of the transmission / reception antenna to about several times the number of sub antennas.

  The present invention has been made to solve the above-mentioned problems, and by introducing the maximum eigenvalue by applying the concept of the beam forming method by eigenvalue expansion, the antenna gain is increased to about several times the number of sub-antennas. An object of the present invention is to obtain an antenna device capable of expanding the combined beam width to the same level as that of the sub-antenna. The present invention is suitable as a beam forming method for a distributed aperture antenna from the viewpoint of versatility by using a signal synthesis method applicable to sub-antennas of arbitrary arrangement.

  An antenna apparatus according to the present invention receives a signal through a plurality of reception sub-antennas having distributed directional beams, an integrated beam control unit that controls beam directing directions of the plurality of reception sub-antennas, and the reception sub-antenna. Receiver, a matrix calculator that calculates the covariance matrix of the output signal of the receiver, a vector calculator that calculates the eigenvector corresponding to the maximum eigenvalue of the covariance matrix, and the output signal of each receiver using the eigenvector as a weight A reception processing unit including a multiplication unit that multiplies and a sum calculation unit that calculates and outputs the sum of the output signals of each receiver multiplied by the weight.

  According to the present invention, a plurality of reception sub-antennas having distributed directional beams, an integrated beam control unit that controls the beam directing directions of the plurality of reception sub-antennas, and a reception that receives a signal via the reception sub-antenna. A matrix calculation unit for calculating the covariance matrix of the output signal of the receiver, a vector calculation unit for calculating the eigenvector corresponding to the maximum eigenvalue of the covariance matrix, and multiplying the output signal of each receiver using the eigenvector as a weight And a reception processing unit having a sum calculation unit that calculates and outputs the sum of the output signals of the receivers multiplied by the weights. The effect of forming a high-gain receive beam equivalent to an aperture receive antenna and expanding the combined receive beam width to the same level as the receive sub-antenna A. As a result, the area covering the space at the same time as the increase of the antenna gain can be greatly expanded compared to the conventional technology.For example, when applied to radar, the detection performance has been considered to be contradictory. It is possible to improve both the space search efficiency.

  The antenna apparatus of the present invention has a so-called blind beamformer that does not use information on the position and phase error of each receiving subantenna, unlike the conventional beamformer method. For this reason, there is no need to obtain information on the position and phase error of each receiving sub-antenna in advance, and there is an effect that calibration work for obtaining these information can be omitted.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of an antenna apparatus according to Embodiment 1 of the present invention, in which a reception beam having a high gain and a wide beam width is formed by combining reception signals of a plurality of reception sub-antennas arranged in a distributed manner. 1 shows a distributed aperture antenna device for use in a vehicle. The antenna apparatus according to Embodiment 1 includes a plurality of reception sub-antennas 1, an integrated beam controller (integrated beam control unit) 2, a receiver 3, and a reception eigenvalue beamforming processor (reception processing unit) 4.

  The plurality of receiving sub-antennas 1 all have the same directional beam, and are linearly, planarly or three-dimensionally distributed at equal intervals or unequal intervals at any interval from the number of apertures to several hundred times. Is done. The integrated beam controller 2 controls so that the beam of each receiving subantenna 1 is directed in the same direction. The receiver 3 is provided for each reception subantenna 1 and amplifies the signal received by each reception subantenna 1 and converts it into a digital signal. The reception eigenvalue beamforming processor 4 is a processor that forms a combined beam of sub-antennas from the output of each receiver 3, and includes a covariance matrix calculation unit (matrix calculation unit) 5 and a maximum eigenvector calculation unit (vector calculation unit). 6, a complex multiplier (multiplier) 7 and a sum calculator 8.

  The covariance matrix calculation unit 5 performs covariance matrix calculation on the output signal of each receiver 3. The maximum eigenvector calculation unit 6 calculates the maximum eigenvector of the covariance matrix calculated by the covariance matrix calculation unit 5. The complex multiplier 7 is provided for each receiver 3 and multiplies the output of each receiver 3 by using the maximum eigenvector as a weight. The sum total calculation unit 8 inputs the calculation result of each complex multiplication unit 7, calculates the sum, and outputs it as a combined beam.

Next, the operation will be described.
The reception beams of the plurality of reception sub-antennas 1 distributed as described above are controlled so as to be directed in the same direction by the beam control signal from the integrated beam controller 2. For example, when the antenna apparatus according to the first embodiment is implemented by a radar apparatus or the like that needs to scan the space, the integrated beam controller 2 sequentially sets the required space while matching the beam directing directions of the reception sub-antenna 1. Control to scan.

  Signal waves that arrive at each receiving sub-antenna 1 are received by the receiver 3 and converted into digital signals. In addition, when the receiving subantenna 1 is configured by a digital beam forming antenna, the function of the receiver 3 is realized by a so-called beamformer. In this case, the beam control signal from the integrated beam controller 2 is input to this beam former. In the beam combining between the receiving sub-antennas described below, there is no functional difference as a sub-antenna between the case of the normal type antenna shown in FIG. 1 and the digital beam forming antenna. Therefore, in the following, description will be made on behalf of the normal type antenna shown in FIG.

  The reception signals from the sub-antennas 1 converted into digital signals by the receiver 3 are combined by the reception eigenvalue beamforming processor 4 and output as a combined beam. Although not shown in the figure, the output stage of the receiver 3 or the input of the processor 4 so that there is no time difference in the signal transmission time between the receiver 3 of each receiving sub-antenna 1 and the eigenvalue beamforming processor 4 for reception. A delay circuit is provided in the stage, and the transmission time is appropriately corrected by the delay circuit.

  Here, processing in the eigenvalue beamforming processor 4 for reception will be described. A covariance matrix calculator 5 in the eigenvalue beamforming processor for reception 4 calculates a covariance matrix for the output of each receiver 3 corresponding to the received signal from each subantenna 1. The maximum eigenvector calculation unit 6 receives a covariance matrix for the output of each receiver 3 from the covariance matrix calculation unit 5, calculates these eigenvalues, and obtains an eigenvector corresponding to the maximum eigenvalue.

  On the other hand, the complex multiplier 7 multiplies the output of each receiver 3 by using the maximum eigenvector obtained by the maximum eigenvector calculator 6 as a weight. These multiplication results are summed by the sum calculation unit 8 to form a combined beam.

Next, details of the beam synthesis processing according to the first embodiment will be described.
First, when it is assumed that the distance to the wave source is sufficiently longer than the length between both ends of the arrangement of the reception sub-antenna 1, the incoming wave to each reception sub-antenna 1 can be regarded as a plane wave. Further, here, the beam widths and directivity directions of the reception sub-antennas 1 arranged in a distributed manner are the same. Thus, according to the theory of the array antenna, the combined directivity pattern G (θ) is obtained by considering one sub-antenna pattern G _E (θ) and the sub-antenna as one element as shown in the following formula (1). It can be expressed by the product of the array factor F _A (θ) of the entire arrangement.

  From the relationship of the above formula (1), if an array factor having a high gain can be formed regardless of the signal direction, a combined pattern with a high gain and a beam width equivalent to that of each sub-antenna can be obtained. In order to form such an array factor, in the first embodiment, a part of the idea of a beam forming method using eigenvalue expansion, which is a kind of adaptive antenna algorithm that adaptively forms an array factor from an antenna input signal. Apply.

This will be specifically described. First, the number of reception sub-antennas 1 is K, and the reception signal of the k-th reception sub-antenna 1 is x _k (t) (t is time, k = 1, 2,..., K). At this time, each received signal x _k (t) is multiplied by a complex weight w _k and then summed to obtain an output as a result of beam formation. Here, the weight vector W whose elements input vector X and w _n and elements x _k (t), the following equation (2), defined in (3). However, the superscript H represents a transposed matrix. Therefore, the combined beam output y (t) can be expressed as the following equation (4).

The covariance matrix R _xx of the reception signal of each reception subantenna 1 is defined by the following equation (5). By using this covariance matrix R _xx , the output power P _out can be expressed by the following equation (6). E [] is a time average.

FIG. 2 is a diagram of a coordinate system showing element antenna positions and radio wave arrival directions. The radio wave arrival angles θ and φ are defined as shown in the figure. At this time, if the position coordinates of the phase center of the k-th receiving subantenna are set as (x _k , y _k , z _k ), the propagation path difference d _k between this and the reference point O can be expressed by the following equation (7). . Using the following equation (7), the array response vector a of the radio wave arrival angles θ and φ is defined by the following equation (8). Note that λ is a wavelength.

  The conventional beam former method uses an array response vector in the beam forming direction as a weight vector. According to Non-Patent Document 1, in this case, the gain of the array factor is K in the beam forming direction, and as a result, the gain of the combined pattern is K times that of the receiving sub-antenna in the beam forming direction.

  However, in the conventional beamformer method, if the length between both ends of the sub antenna arrangement is M times the sub antenna opening length, the beam width of the array factor is about 1 / M of the sub antenna, and the beam width of the combined pattern is also It has been shown to be very narrow. Moreover, as is clear from the above equation (8), in order to calculate the array response vector in the beam forming direction, the position coordinates of each receiving sub-antenna need to be accurately known, and between the receiving sub-antennas It is necessary to accurately calibrate the phase error.

On the other hand, in the synthesis pattern formation according to the first embodiment, the weight vector is adaptively calculated using the covariance matrix of the received signal. For example, regardless of the direction of arrival of the received signal, the output power P _out which is obtained by the formula (6) Given that determine the weight vector W such that the maximum. Here, if normalization is performed so that the gain with respect to noise becomes 1, this problem can be described by an optimization formula shown by the following formula (9).

When the above equation (9) is solved by the Lagrange's undetermined multiplier method, the following equation (10) is obtained for the local optimal solution W hat of the weight vector (shown as a reading in relation to the electronic application). Where η is a Lagrange multiplier. This equation (10) shows that η is the eigenvalue of the covariance matrix R _xx and W hat is its eigenvector. Here, since R _xx is a K-dimensional Hermitian matrix, it has K eigenvalues. Further, when the transposition matrix of W hat is applied from the left side of the above equation (10) having K eigenvalues, the relationship of the following equation (11) is derived, and the left side becomes the output power for the W hat.

Therefore, the maximum eigenvalue among the K eigenvalues of R _xx is the maximum output power, and the corresponding eigenvector is the optimum weight vector. That is, by obtaining an eigenvector corresponding to the maximum eigenvalue of the covariance matrix of the received signal and using this as a weight, the maximum output power (that is, the gain of the array factor = K) can be obtained regardless of the signal arrival direction. As a result, a combined pattern having a gain K times that of the sub-antenna and a beam width equivalent to that of the sub-antenna is obtained.

In addition, many mathematical methods such as Jacobian method, QR method, and Householder method are known as a general method for obtaining eigenvalues and eigenvectors of a matrix. In particular, the covariance matrix is a Hermitian matrix. Therefore, either method may be used and a solution can be obtained relatively easily (see References).
(References)
Hideyo Nagashima, “Numerical Calculation Method”, pp. 117-127, Tsuji Shoten, Tokyo, 1979

  FIG. 3 is a diagram showing a calculation example of a combined pattern to which the beam forming algorithm according to the first embodiment is applied and a sub-antenna pattern. FIG. 3A shows a conventional beamformer method. FIG. 5B shows the result of beam formation according to the first embodiment. In addition, the pattern which attached | subjected the code | symbol A in the figure (a) is a synthetic | combination pattern, and the pattern which attached | subjected the code | symbol B is a subantenna pattern. Moreover, the pattern which attached | subjected the code | symbol C in the same figure (b) is a synthetic | combination pattern, and the pattern which attached | subjected the code | symbol D is a subantenna pattern.

  In the example shown in the figure, when 10 reception sub-antennas are randomly arranged on the z-axis of the coordinate system shown in FIG. 2 with an average interval of 20λ, the combined pattern of 10 reception sub-antennas and each reception sub-antenna The output pattern obtained by the normal beam former method and the beam forming algorithm according to the first embodiment is described. The angle of arrival on the horizontal axis in the figure is θ shown in the coordinate system of FIG.

  Further, in the result of the conventional beamformer method shown in FIG. 3A, the beam directivity angle of the receiving sub antenna is θ = 90 ° and the beam width is 0.25 °. On the other hand, in FIG. 3B, the beam directivity angle of the receiving sub-antenna is θ = 90 °, and the beam width is 7.1 °. Also from this calculation example, by using the first embodiment, it is possible to improve the reception gain as compared with the sub-antenna and to achieve the same beam width as that of the sub-antenna. Reduction in beam width can be avoided.

  As described above, according to the first embodiment, a plurality of receiving sub-antennas 1 having the same directional beam distributed and an integrated beam controller 2 that controls the beam directing directions of the plurality of receiving sub-antennas 1. A receiver 3 that receives a signal via the reception subantenna 1, a covariance matrix calculation unit 5 that calculates a covariance matrix of the output signal of the receiver 3, and an eigenvector corresponding to the maximum eigenvalue of the covariance matrix. A maximum eigenvector calculation unit 6 to be calculated; a complex multiplication unit 7 that multiplies the output signal of each receiver 3 by using the eigenvector as a weight; and a total calculation that calculates and outputs the sum of the output signals of each receiver 3 multiplied by the weight Since the receiving eigenvalue beamforming processor 4 having the unit 8 is provided, the receiving gain can be improved over the receiving subantenna 1, and the receiving subantenna 1 It can realize the same beam width. Thereby, for example, even when applied to radar, it is possible to achieve both improvement in detection performance and improvement in space search efficiency.

  Also, according to the first embodiment, as is clear from the above equation (10), the beam forming according to the first embodiment does not use information on the position and phase error of each reception sub-antenna. Therefore, unlike the normal beam former method, there is a great practical advantage that there is no need for calibration work to obtain such information in advance.

  Furthermore, in the first embodiment, a general case is assumed in which the number and positions of wave sources to be received are uncertain. In such a case, it is necessary to always calculate the maximum eigenvector, but if the position of the source can be regarded as invariant within a certain time, or at least the direction of the source is known, the source position It is also possible to calculate the maximum eigenvector only at the time of the change or once in the direction of the wave source and store it in the memory, and then repeatedly apply this to reduce the amount of calculation.

  However, it goes without saying that this case also has the same effect as described above. FIG. 1 shows an example in which the integrated beam controller 2 controls the directivity direction of each reception sub-antenna 1, but when the wave source direction is fixed, the directivity direction of each reception sub-antenna 1 is changed to the wave source direction. Even if the integrated beam controller 2 is omitted while being fixed to, the same effect is obtained. It should be noted that these changes are also established in the second and subsequent embodiments described below.

Embodiment 2. FIG.
The second embodiment shows a modified form of the reception sub-antenna configuration in the first embodiment, and uses reception sub-antennas with different antenna patterns.
FIG. 4 is a diagram showing a configuration of an antenna apparatus according to Embodiment 2 of the present invention. K reception sub-antennas 1-1 to 1-K are arranged in a distributed manner as in the first embodiment, but have different antenna patterns. K reception beam controllers (beam control units) 9 provided corresponding to the reception sub-antennas 1-1 to 1-K respectively change the beam directing directions of the reception sub-antennas 1-1 to 1-K to integrated beams. The beam control signal from the controller 2 is shifted by a predetermined amount. The other components are the same as those in FIG. 1, and the same reference numerals are given and redundant description is omitted.

Next, the operation will be described.
The integrated beam controller 2 generates a beam control signal so that the beams of the reception sub-antennas 1-1 to 1-K are directed in the same direction as in the first embodiment. Beam control signals from the integrated beam controller 2 to the reception sub-antennas 1-1 to 1-K are relayed to the reception beam controller 9 provided for each of the reception sub-antennas 1-1 to 1-K.

  When the reception beam controller 9 of each of the reception sub-antennas 1-1 to 1-K receives the beam control signal from the integrated beam controller 2, the reception beam controller 9 receives a predetermined amount from the actual beam directing direction specified by the beam control signal. A control signal that shifts is generated and output to the corresponding reception sub-antenna. Thereby, the reception sub-antennas 1-1 to 1-K shift the beam directing direction by a predetermined amount according to the control signal of the reception beam controller 9. The subsequent operations are the same as those in the first embodiment.

Next, the beam synthesis process according to the second embodiment will be described.
In the second embodiment, beam combining is performed by using the same algorithm as in the first embodiment, using different antenna patterns (for example, patterns having different gains, beam widths, and the like) and receiving sub-antennas having different beam directing directions. In this case, it is equivalent to applying a weight corresponding to the gain difference of the receiving sub-antenna to each element of the covariance matrix R _xx of the above equation (5). As a result, the resultant combined pattern is the power sum of each sub-antenna pattern.

  Therefore, if a plurality of receiving sub-antennas with appropriate patterns are arranged according to the purpose (however, the position is arbitrary) and the beam directing directions are shifted, a composite pattern having a shape suitable for the purpose is formed. can do. The other processing contents are the same as those in the first embodiment.

Hereinafter, a specific description will be given using a numerical example shown in FIG.
FIG. 5 is a diagram illustrating a calculation example of a combined pattern to which the beam forming algorithm according to the second embodiment is applied and a sub-antenna pattern. FIG. 6A is a calculation example in the case where the beam directing directions of five reception sub-antennas having the same pattern are shifted and combined, and FIG. 5B shows five reception sub-antennas having different antenna patterns. This is an example of calculation when the beam directing directions are shifted and combined. Moreover, the pattern which attached | subjected the code | symbol E in the figure (a) is a synthetic | combination pattern, and the pattern which attached | subjected the code | symbol F is a subantenna pattern. Moreover, the pattern which attached | subjected the code | symbol G in the same figure (b) is a synthetic | combination pattern, and the pattern which attached | subjected the code | symbol H is a subantenna pattern.

  In FIG. 6A, the beam width of each receiving sub-antenna is 7.1 °, and each receiving beam controller 9 is connected to each receiving sub-antenna with respect to the beam forming direction 90 ° indicated by the integrated beam controller 2. The beam directing direction is shifted by 7.1 °. As is clear from FIG. 6A, the gain of the resultant combined pattern is equivalent to that of the receiving sub-antenna, but the beam width is expanded about 5 times. Such a composite pattern is effective in applications that place importance on the radar's spatial search efficiency.

  In the example of FIG. 5B, the sub antenna pattern and its beam directing direction are appropriately selected so that the combined pattern is a so-called cosecant square pattern. If such a pattern is formed in the elevation angle direction by the reception beam controller 9 and the entire combined pattern is scanned in the azimuth direction by the integrated beam controller 2, a search radar having a certain altitude coverage can be efficiently obtained. realizable.

  As described above, according to the second embodiment, the reception beam controller 9 controls the beam directing directions of a plurality of reception sub-antennas having appropriate patterns, so that a composite pattern having a shape suitable for the purpose of use can be obtained. It can be formed relatively easily.

Embodiment 3 FIG.
In the third embodiment, the array response vector of the virtual wave source is used in the calculation of the covariance matrix instead of the output of the receiver 3 in the first and second embodiments. Thereby, the calculation amount of the maximum eigenvector can be reduced.

  FIG. 6 is a diagram showing a configuration of an antenna apparatus according to Embodiment 3 of the present invention. In addition, the same code | symbol is attached | subjected to the component which is the same as that of FIG. 1, or equivalent, and the overlapping description is abbreviate | omitted. The sub-antenna correction memory (correction memory) 10 stores reception sub-antenna position information and phase error information. The virtual wave source array response vector calculation unit (array response vector calculation unit) 11 calculates an array response vector of the virtual wave source.

Next, the operation will be described.
The integrated beam controller 2 generates a beam control signal so that the beams of the reception sub-antennas 1 are directed in the same direction as in the first embodiment. The beam control signal from the integrated beam controller 2 to each reception sub-antenna 1 is input to the virtual wave source array response vector calculation unit 11 in addition to each reception sub-antenna 1.

  The virtual wave source array response vector calculation unit 11 has a plurality of combined beam widths within a required combined beam width with respect to the center direction of the combined pattern indicated by the beam control signal for each receiving subantenna 1 output from the integrated beam controller 2. Assuming a virtual wave source, a plurality of array response vectors corresponding to these directions are calculated. In the course of this calculation, the position information and phase error of each reception sub-antenna are obtained from the sub-antenna correction memory 10 that stores the position information and phase error information of each reception sub-antenna 1 measured or calibrated in advance by a measuring instrument or the like. Information is read and used.

  The array response vector corresponding to the beam directing direction of each reception subantenna 1 calculated by the virtual wave source array response vector calculation unit 11 is input to the covariance matrix calculation unit 5. The covariance matrix calculation unit 5 calculates a covariance matrix corresponding to the virtual wave source using the input array response vector. The maximum eigenvector calculation unit 6 receives the covariance matrix calculated by the covariance matrix calculation unit 5 and calculates these eigenvalues to obtain an eigenvector corresponding to the maximum eigenvalue for each receiver 3. The subsequent operations are the same as those in the first embodiment.

Next, beam combining processing according to Embodiment 3 will be described.
The purpose of Embodiment 3 is to achieve the same effect as Embodiment 1 and Embodiment 2 with a smaller amount of calculation when the position information and phase error information of the receiving sub-antenna are obtained in advance. Is. That is, the covariance matrix calculation unit 5 of the first embodiment shown in FIG. 1 and the covariance matrix calculation unit 5 of the second embodiment shown in FIG. It is necessary to form a beam adaptively, and the covariance matrix is calculated in real time using the output of each receiver 3. As a result, the subsequent maximum eigenvector calculation unit 6 also requires real-time calculation, which may increase the amount of calculation.

  On the other hand, if the position information and phase error information of the reception sub-antenna 1 can be obtained in advance, the sub-antenna correction memory 10, the virtual wave source array response vector calculation unit 11, and the covariance matrix calculation unit 5 Thus, the number of covariance matrix calculations can be reduced.

The covariance matrix R _xx shown in the above equation (5) can be expressed as the following equation (12) when array response vectors in the direction of N virtual wave sources are used. Here, P _i is an assumed received power value from the i-th virtual wave source, σ _i ² is virtual noise input power, and I is a unit matrix. Further, a _i is an array response vector in the i-th virtual wave source direction.

  The virtual wave source array response vector calculation unit 11 assumes a plurality of virtual wave sources within a required combined beam width with respect to the center direction of the combined pattern indicated by the beam control signal, and receives each received sub antenna from the sub antenna correction memory 10. 1 position information and phase error information are obtained, and an array response vector corresponding to the virtual wave source direction is calculated using the above equation (7). The covariance matrix calculation unit 5 estimates the covariance matrix of each reception subantenna 1 from the above equation (12) using the calculated array response vector.

  It is appropriate that the typical virtual wave source interval is about the beam width when the reception sub-antenna 1 is synthesized by a normal beamformer method, and the number of virtual wave sources is usually the required beam of the synthesis pattern. It is given by the ratio between the width and the interval between the virtual wave sources. In the third embodiment, the above process is performed by the sub-antenna correction memory 10 and the virtual wave source array response vector calculation unit 11 so as to satisfy this condition. Other processes are the same as those in the first embodiment.

  As described above, according to the third embodiment, it is not necessary to calculate the covariance matrix in real time, and the calculation may be performed every time the pointing direction of the combined beam is changed by the beam control signal. Accordingly, the subsequent calculation of the maximum eigenvector can similarly reduce the number of calculations. This means that it is not necessary to change the weight for beam synthesis unless the direction of the synthesized beam is changed. If there is an actual wave source in a direction close to the virtual wave source, the output power increases due to the same effect as in the first embodiment.

  Further, since the virtual wave source is distributed within a required combined beam width, the combined pattern has a high gain and a wide beam width as a result of these. That is, according to the third embodiment, if the position and phase error of each reception sub-antenna 1 are measured in advance, the same effect as in the first embodiment can be obtained with a smaller calculation amount. .

  In the third embodiment, an example in which the sub-antenna correction memory 10 and the virtual wave source array response vector calculation unit 11 are added to the first embodiment has been described. However, the third embodiment may be applied to the second embodiment. Needless to say, there is a similar effect.

Embodiment 4 FIG.
In the fourth embodiment, the virtual wave source is interpolated from the measured value of the array response vector using the known wave source instead of the position information and the phase error prior information, which are known information in the third embodiment. An array response vector is calculated.

  FIG. 7 is a diagram showing a configuration of an antenna apparatus according to Embodiment 4 of the present invention. In addition, the same code | symbol is attached | subjected to the component which is the same as that of FIG. 6, or is equivalent, and the overlapping description is abbreviate | omitted. The array response vector memory 12 stores an array response vector obtained from a received signal from a known wave source.

Next, the operation will be described.
The integrated beam controller 2 generates a beam control signal so that the beams of the reception sub-antennas 1 are directed in the same direction as in the first embodiment. The beam control signal from the integrated beam controller 2 to each reception sub-antenna 1 is input to the virtual wave source array response vector calculation unit 11 in addition to each reception sub-antenna 1.

  In the virtual wave source array response vector calculation unit 11, the center direction of the combined pattern indicated by the beam control signal for each reception subantenna 1 output from the integrated beam controller 2 is the same as in the third embodiment. Assuming a plurality of virtual wave sources within a required combined beam width, an array response vector in the known wave source direction stored in the array response vector memory 12 is read, and a plurality of virtual wave sources corresponding to the virtual wave source direction are calculated by interpolation calculation of the array response vector. Compute the array response vector.

  The array response vector memory 12 used in this calculation process stores at least three or more array response vectors having different arrival directions as the output of the receiver 3 for a wave source whose arrival direction is known in advance. Store the known wave source.

  The array response vector corresponding to the beam directing direction of each reception subantenna 1 calculated by the virtual wave source array response vector calculation unit 11 is input to the covariance matrix calculation unit 5. The covariance matrix calculation unit 5 calculates a covariance matrix corresponding to the virtual wave source using the input array response vector. The maximum eigenvector calculation unit 6 receives the covariance matrix calculated by the covariance matrix calculation unit 5 and calculates these eigenvalues to obtain an eigenvector corresponding to the maximum eigenvalue for each receiver 3. The subsequent operations are the same as those in the first embodiment.

Next, beam combining processing according to Embodiment 4 will be described.
In the fourth embodiment, when there are a plurality of wave sources whose arrival directions are known, the same effect as in the first and second embodiments can be achieved with a smaller amount of calculation. The array response vector a in the above equation (8) can be obtained as the output of the receiver 3 for a known wave source.

  Therefore, by measuring array response vectors of three or more known wave sources having different arrival directions in advance and storing them in the array response vector memory 12, the interpolation source vector direction in the third embodiment can be calculated from these interpolation calculations. Can be obtained. In the fourth embodiment, the above processing is performed by the array response vector memory 12 and the virtual wave source array response vector calculation unit 11. Other processes are the same as those in the third embodiment.

  As described above, according to the fourth embodiment, it is not necessary to calculate the covariance matrix in real time, as in the third embodiment. Therefore, the same calculation as in the first embodiment can be performed with a smaller amount of calculation. An effect can be obtained. If there are a plurality of wave sources whose arrival directions are known in advance, the position information and phase error information of each reception subantenna required in the third embodiment are not required.

  In the fourth embodiment, an example in which the array response vector memory 12 and the virtual wave source array response vector calculation unit 11 are added to the configuration of the first embodiment has been described. However, the fourth embodiment is applied to the configuration of the second embodiment. However, it goes without saying that the same effect can be obtained.

Embodiment 5. FIG.
The fifth embodiment is based on the same concept as the third embodiment, and relates to a transmission distributed aperture antenna that forms a transmission beam having a high gain and a wide beam width by combining a plurality of transmission sub-antennas arranged in a distributed manner. is there.

  FIG. 8 is a diagram showing a configuration of an antenna apparatus according to Embodiment 5 of the present invention. The antenna apparatus according to the fifth embodiment includes a plurality of transmission sub-antennas 13, an excitation signal generator 14, an integrated beam controller 2, a transmitter 18, and a transmission eigenvalue beamforming processor (transmission processing unit) 15. Each of the plurality of transmission sub-antennas 13 has a directional beam, and is arranged linearly, planarly, or three-dimensionally at equal intervals or unequal intervals at any interval from the number of apertures to several hundred times. . The transmitter 18 converts the excitation signal, which is a digital signal, into a transmission signal, amplifies it, and supplies it to each transmission sub-antenna 13. In addition, the same code | symbol is attached | subjected to the component which is the same as that of FIG. 6, or is equivalent, and the overlapping description is abbreviate | omitted.

  The excitation signal generator 14 generates an excitation signal that is a digital signal that is a source signal for transmission. The eigenvalue beamforming processor 15 for transmission is a processor that creates an excitation signal for each transmission sub-antenna 13 from the original excitation signal generated by the excitation signal generator 14 so that a combined pattern can be obtained in space. The matrix calculation unit 5, the maximum eigenvector calculation unit 6, the sub-antenna correction memory 10, the virtual wave source array response vector calculation unit 11, the signal distribution unit 16, and the complex multiplication unit 17 are configured.

  The signal distributor 16 distributes the excitation signal generated by the excitation signal generator 14 to each transmission sub-antenna 13. The plurality of complex multipliers 17 multiply the excitation signal distributed by the signal distributor 16 by the beam combining weight calculated by the maximum eigenvector calculator 6. Other internal configurations are the same as those shown in the first embodiment and the third embodiment.

Next, the operation will be described.
First, an excitation signal, which is a source signal generated by the excitation signal generator 14, is input to a transmission eigenvalue beamforming processor 15. The signal distributor 16 in the processor 15 distributes the excitation signal from the excitation signal generator 14 for each number of transmission sub-antennas 13. The complex multiplication unit 17 provided corresponding to each transmission sub-antenna 13 calculates the excitation signal distributed by the signal distribution unit 16 by the maximum eigenvector calculation unit 6 corresponding to each transmission sub-antenna 13. Multiply the beam combining weights. Thereby, it is converted into an excitation signal for each transmission sub-antenna 13 and output to the transmitter 18 provided for each transmission sub-antenna 13.

  In the transmitter 18, the input excitation signal is converted into a transmission signal, amplified, and supplied to each transmission sub-antenna 13. As a result, signals transmitted from a plurality of transmission sub-antennas 13 that are dispersedly arranged are combined in space to form a directional beam having a high gain and a wide beam width. Note that the directing direction of the combined beam is controlled by a beam control signal generated by the integrated beam controller 2 to each transmission sub-antenna 13. Upon receiving this beam control signal, each transmission sub-antenna 13 adjusts the beam directing direction to the direction specified by the beam control signal.

Here, the transmission beam combining process will be briefly described.
The original excitation signal by the excitation signal generator 14 input to the transmission eigenvalue beamforming processor 15 is input to the signal distributor 16. The signal distribution unit 16 distributes the input excitation signal for each transmission sub-antenna 13.

  On the other hand, the integrated beam controller 2 generates a beam control signal so that the beam of each transmission sub-antenna 13 is directed in the designated direction, as in the first embodiment. The beam control signal from the integrated beam controller 2 to each transmission sub-antenna 13 is input to the virtual wave source array response vector calculation unit 11 in addition to each transmission sub-antenna 13.

  In the virtual wave source array response vector calculation unit 11, a plurality of within a required combined beam width with respect to the center direction of the combined pattern indicated by the beam control signal for each transmission sub-antenna 13 output from the integrated beam controller 2. Assuming a virtual wave source, a plurality of array response vectors corresponding to these directions are calculated. In the course of this calculation, the position information and phase error of each transmission sub-antenna are obtained from the sub-antenna correction memory 10 that stores the position information and phase error information of each transmission sub-antenna 13 measured or calibrated in advance by a measuring instrument or the like. Information is read and used.

  The array response vector calculated by the virtual wave source array response vector calculation unit 11 is input to the covariance matrix calculation unit 5. The covariance matrix calculation unit 5 calculates a covariance matrix corresponding to the virtual wave source using the input array response vector. The maximum eigenvector calculation unit 6 receives the covariance matrix calculated by the covariance matrix calculation unit 5, calculates these eigenvalues, and obtains an eigenvector corresponding to the maximum eigenvalue for each transmitter 18.

  The complex multiplier 17 multiplies the excitation signal distributed for each transmission subantenna by the signal distributor 16 by the eigenvector for each transmitter 18 obtained by the maximum eigenvector calculator 6 as a beam combining weight. In the transmitter 18, the excitation signal processed by the complex multiplier 17 is converted into a transmission signal, amplified, and supplied to each transmission sub-antenna 13. It should be noted that the weight creation operation executed by the function from the sub-antenna correction memory 10 to the maximum eigenvector calculation unit 6 is the same as that of the third embodiment.

Next, details of the transmission beam combining process will be described.
In a general array antenna, it is obvious that the equation holds even if the left side and the right side of the above equation (4) are reversed. As a result, the maximum power is obtained as a result of multiplying and adding an appropriate weight to the received signal of each receiving subantenna 1 received from a certain direction, and after the excitation signal is distributed and multiplied by the same weight as above If transmission is performed from each transmission sub-antenna 13, maximum power is transmitted in that direction, that is, a directional beam is formed in that direction.

  As described above, according to the fifth embodiment, by using the circuit configuration and weight shown in FIG. 8, a transmission pattern having the same property as the reception synthesized pattern obtained in the third embodiment can be obtained by spatial synthesis. Can be formed. That is, a combined pattern having a transmission gain higher than that of the transmission sub-antenna 13 and a wide transmission beam width can be formed.

  In the fifth embodiment, as in the third embodiment, it is necessary to measure the position information and the phase error of the transmission subantenna 13 in advance and store them in the subantenna correction memory 10.

Embodiment 6 FIG.
The sixth embodiment relates to a distributed aperture antenna apparatus that enables transmission and reception by using one of the reception sub-antennas of the first to fourth embodiments as a transmission / reception sub-antenna.

  FIG. 9 is a diagram showing a configuration of an antenna apparatus according to Embodiment 6 of the present invention. In the figure, the transmission / reception sub-antenna 19 is arranged separately from the reception sub-antennas 1 which are arranged in a distributed manner, and has a directional beam transmission / reception function. The transmission / reception switch (transmission / reception switching unit) 20 switches between a transmission signal and a reception signal to the transmission / reception sub-antenna 19. The signal detector 21 detects the reception signal combined with the sub-antenna. In addition, the same code | symbol is attached | subjected to the component which is the same as that of FIG.1 and FIG.8, or equivalent, and the overlapping description is abbreviate | omitted.

Next, the operation will be described.
First, the case of transmission will be described. The reception beam of the reception subantenna 1 and the transmission / reception subantenna 19 is controlled by the beam control signal of the integrated beam controller 2 so that the directivity directions are the same, and the transmission beam of the transmission / reception subantenna 19 is also directed in the required direction. To be controlled.

  The excitation signal generated by the excitation signal generator 14 is converted and amplified to a transmission signal by the transmitter 18, and the transmission destination is switched to the transmission / reception sub-antenna 19 by the transmission / reception switch 20. Thereby, a transmission signal is radiated | emitted to space via the transmission / reception subantenna 19. FIG.

  Next, the case of reception will be described. The reception beams of the plurality of reception sub-antennas 1 and transmission / reception sub-antennas 19 that are distributed are controlled so as to be directed in the same direction by a beam control signal from the integrated beam controller 2. Signals received by the reception sub-antenna 1 and the transmission / reception sub-antenna 19 that are distributed are converted into digital signals by the receiver 3. The signal received by the transmission / reception subantenna 19 is switched to the receiver 3 by the transmission / reception switcher 20 and converted into a digital signal by the receiver 3.

  The reception signal converted into a digital signal by the receiver 3 is input to the reception eigenvalue beamforming processor 4. Although not shown in the figure, the output stage of the receiver 3 does not cause a time difference in signal transmission time from the receiver 3 of each reception sub-antenna 1 and transmission / reception sub-antenna 19 to the eigenvalue beamforming processor 4 for reception. Alternatively, a delay circuit is provided at the input stage of the processor 4 and the transmission time is appropriately corrected by this delay circuit.

  The covariance matrix calculator 5 in the reception eigenvalue beamforming processor 4 calculates a covariance matrix for the output of each receiver 3 corresponding to the received signal from each sub-antenna 1 and transmission / reception sub-antenna 19. The maximum eigenvector calculation unit 6 receives the covariance matrix for the output of each receiver 3 from the covariance matrix calculation unit 5, calculates the eigenvalues of these covariance matrices and receives the receiver 3 as in the first embodiment. Each time, an eigenvector corresponding to the maximum eigenvalue is obtained.

  On the other hand, the complex multiplier 7 multiplies the output of each receiver 3 by using the maximum eigenvector obtained by the maximum eigenvector calculator 6 as a weight. These multiplication results are summed by the sum calculation unit 8 to form a combined beam. The combined beam formed by the sum calculation unit 8 is output to the signal detector 21. Thereby, the combined beam of the received signal is detected by the signal detector 21.

  As described above, according to the sixth embodiment, the entire distributed aperture antenna can be transmitted and received, and at the time of reception, similarly to the first embodiment, the gain is K times that of each sub-antenna (K: reception). The number of sub-antennas) can be as large as the combined width of the sub-antenna. Further, since one transmission / reception sub-antenna is used at the time of transmission, a pattern is obtained in which the gain is lower than the reception combined pattern but the beam width is substantially equal.

  As a result, not only can this be applied when a transmission / reception function is required, such as a radar, but a combined pattern with a high gain and a wide beam width can be obtained in reception as in the first embodiment. Other functions and effects are the same as those of the first embodiment.

  In Embodiment 6 described above, an example is shown in which one transmission / reception sub-antenna having a transmission function is provided. However, the reception function is limited to other reception sub-antennas, and one transmission-dedicated sub-antenna is provided. Even if the transmission / reception switch 20 is omitted, the same effect can be obtained.

  Further, although the example in which the sixth embodiment is applied to the first embodiment has been described, it is needless to say that the same effect can be obtained even if the sixth embodiment is applied to the second to fourth embodiments.

Embodiment 7 FIG.
In the seventh embodiment, the effective transmission power is improved compared to the sixth embodiment by replacing a plurality of reception sub-antennas of the first to fourth embodiments with transmission / reception sub-antennas. Note that the transmission / reception distributed aperture antenna apparatus according to the seventh embodiment can be applied to a case where the transmission beam and the reception beam are directed in the same direction as in a radar.

  FIG. 10 is a diagram showing a configuration of an antenna device according to Embodiment 7 of the present invention, and shows an example in which all sub-antennas are configured with transmission / reception sub-antennas for the sake of simplicity. In the figure, a modulator (modulation processing unit) 22 spread-modulates the excitation signal on the frequency axis or the time axis. The demodulator (demodulation processing unit) 23 demodulates the modulated signal. The reception eigenvalue beamforming processors 4 are provided in parallel by the number of transmission / reception sub-antennas 19. In addition, the same code | symbol is attached | subjected to the component which is the same as that of FIG.1 and FIG.9, or it corresponds, and the overlapping description is abbreviate | omitted.

Next, the operation will be described.
First, the case of transmission will be described. The transmission beam of the transmission / reception subantenna 19 is controlled by the beam control signal of the integrated beam controller 2 so that the directivity directions are the same. The excitation signal generated by the excitation signal generator 14 is spread on the frequency axis or spread and encoded on the time axis by the modulator 22 and distributed to the transmitter 18 provided for each transmission / reception sub-antenna 19.

  11A and 11B are diagrams for explaining the modulation processing by the modulator 22, FIG. 11A shows the case of frequency multiplexing, and FIG. 11B shows the case of time axis multiplexing. In the case of performing the modulation process shown in FIG. 6A, when the modulator 22 receives the original excitation signal generated by the excitation signal generator 14, each of the transmission / reception sub-antennas 19, for example, transmission / reception antennas # 1, # 2,. .., Distributed for each #K, and modulated at different frequencies F1, F2,..., FK for each of the transmission / reception antennas # 1, # 2,.

  In the case of performing the modulation process shown in FIG. 5B, when the modulator 22 receives the original excitation signal generated by the excitation signal generator 14, each of the transmission / reception sub-antennas 19, for example, transmission / reception antennas # 1, # 2,. .., distributed for each #K, shifted in time for each of the transmitting and receiving antennas # 1, # 2,..., #K, and modulated with codes orthogonal to each other.

  The transmitter 18 converts and amplifies the excitation signal modulated as described above into a transmission signal. Thereafter, the transmission signal is sent to the transmission / reception subantenna 19 via the transmission / reception switcher 20 and radiated to the space via the transmission / reception subantenna 19.

  Next, the case of reception will be described. The reception beams of the plurality of transmission / reception sub-antennas 19 arranged in a distributed manner are controlled so as to be directed in the same direction by the beam control signal from the integrated beam controller 2. The signal received by the transmission / reception sub-antennas 19 arranged in a distributed manner is switched to the receiver 3 by the transmission / reception switcher 20 and converted to a digital signal by the receiver 3.

  The reception signal converted into a digital signal by the receiver 3 is demodulated by the demodulator 23 to distinguish which reception signal corresponds to the transmission signal of any transmission / reception sub-antenna 19. These received signals are input to each receiving eigenvalue beamforming processor 4.

  The eigenvalue beamforming processor 4 for reception uses the reception signal input from the demodulator 23 to synthesize a reception beam for each reception signal distinguished by the demodulator 23. The signal detector 21 combines these outputs of the processor 4 to perform final signal detection. Other operations are the same as those in the sixth embodiment.

The outline of the seventh embodiment will be described below.
The antenna device according to the sixth embodiment can transmit and receive with a relatively simple configuration because there is one transmission / reception sub-antenna 19, but has a drawback that the effective transmission power is only the same as that of one sub-antenna. However, if a plurality of sub-antennas are simultaneously transmitted at the same frequency in order to increase the effective transmission power, there is a problem that the transmission pattern is significantly disturbed due to mutual interference and the effective transmission power cannot be improved.

  Therefore, in the seventh embodiment, it is assumed that the transmitting beam and the receiving beam are used in the same direction as in a radar, and each sub-antenna is transmitted by frequency division or time division. The mutual interference between the two is prevented.

  That is, if frequency division transmission is used, the modulator 22 distributes the original excitation signal to the number of sub-antennas to transmit, as shown in FIG. Modulate with. As described above, since an application such as radar is assumed here, the received signal can be regarded as a replica of the transmitted signal or a strong correlation with the transmitted signal. Therefore, the demodulator 23 can separate the received signal in accordance with the transmitted sub antenna by the frequency filter. The separated reception signals are subjected to reception beam synthesis in each reception eigenvalue beamforming processor 4.

  On the other hand, when using time division transmission, as shown in FIG. 11B, the modulator 22 distributes the original excitation signal to the number of sub-antennas to be transmitted, and then shifts the time for each sub-antenna. And modulation with codes orthogonal to each other. Here, since orthogonal codes are used, similarly to the case of frequency division, the demodulator 23 can separate the received signals in accordance with the transmitted sub-antennas by code demodulation. The separated reception signals are subjected to reception beam synthesis in each reception eigenvalue beamforming processor 4.

  As described above, according to the seventh embodiment, even when a plurality of transmission / reception sub-antennas 19 are provided, mutual interference of transmission signals by the respective transmission / reception sub-antennas 19 can be prevented. Can be used for transmission. As a result, the effective transmission power is increased by the number corresponding to the number of sub-antennas compared to the sixth embodiment. Further, since the transmission beam width is equal to each sub-antenna, the sharpening of the beam like the reception beam of the distributed aperture antenna by the normal beam former method does not occur.

  On the other hand, since the processing configuration and operation at the time of reception of the transmission signal of each transmission / reception sub-antenna 19 are the same as those in the first embodiment, the effect of improving the reception gain and widening the reception beam width can be obtained in the same manner. . That is, when the antenna device according to the seventh embodiment is used such that the transmission beam and the reception beam are directed in the same direction like a radar, the gain is improved as compared with the case where both the transmission and reception are sub-antenna alone, In addition, the beam width can be expanded to be equivalent to the sub antenna.

  Further, by applying the seventh embodiment to the first embodiment or the second embodiment, there is an advantage that the position information and the phase error information of each transmission / reception sub-antenna 19 are unnecessary.

  In the seventh embodiment, an example in which all the sub-antennas are configured to be able to transmit and receive is shown. However, the number of sub-antennas for transmission and reception is not necessarily the same, and these numbers are different. It is clear that the same effect is obtained in the case.

  Moreover, although the example in which the seventh embodiment is applied to the configuration of the first embodiment has been described, the same effect can be obtained even if the seventh embodiment is applied to the second to fourth embodiments.

Embodiment 8 FIG.
In this eighth embodiment, the transmission sub-antenna combining method shown in the fifth embodiment is used instead of the frequency division and time division transmission described in the seventh embodiment, so that the eighth embodiment is compared with the sixth embodiment. Thus, the transmission gain is improved.

  FIG. 12 is a diagram showing a configuration of an antenna device according to Embodiment 8 of the present invention, and shows a case where all sub-antennas are configured with transmission / reception sub-antennas for the sake of simplicity of explanation. In addition, the same code | symbol is attached | subjected to the component which is the same as that of FIG.8 and FIG.9, or it corresponds, and the overlapping description is abbreviate | omitted.

Next, the operation will be described.
First, the case of transmission will be described. The excitation signal, which is the source signal generated by the excitation signal generator 14, is input to the transmission eigenvalue beamforming processor 15. The processor 15 converts the input excitation signal into an excitation signal for each transmission / reception sub-antenna 19 and outputs it to the transmitter 18 provided for each transmission / reception sub-antenna 19 in the same manner as in the fifth embodiment.

  In the transmitter 18, the input excitation signal is converted into a transmission signal, amplified, and supplied to each transmission / reception sub-antenna 19 via the transmission / reception switch 20. As a result, signals transmitted from a plurality of transmission / reception sub-antennas 19 that are distributed are combined in space to form a directional beam having a high gain and a wide beam width. The directing direction of the combined beam is controlled by a beam control signal generated by the integrated beam controller 2 and transmitted to each transmission / reception sub-antenna 19. When receiving this beam control signal, each transmitting / receiving sub-antenna 19 adjusts the beam directing direction to the direction specified by the beam control signal.

  Next, the case of reception will be described. The transmission destination of the signal wave arriving at each transmission / reception sub-antenna 19 is switched to the receiver 3 side by the transmission / reception switch 20. The receiver 3 converts the received signal into a digital signal. The reception signal from each transmission / reception subantenna 19 converted into a digital signal by the receiver 3 is input to the reception eigenvalue beamforming processor 4.

  Although not shown in the figure, the output stage of the receiver 3 or the input of the processor 4 so that there is no time difference in the signal transmission time between the receiver 3 of each transmission / reception sub-antenna 19 and the eigenvalue beamforming processor 4 for reception. A delay circuit is provided in the stage, and the transmission time is appropriately corrected by the delay circuit.

  The eigenvalue beamforming processor 4 for reception forms a composite beam for the received signal from each transmission / reception subantenna 19 by the same processing as in the first embodiment. The signal detector 21 performs final signal detection based on the output from the processor 4. Other operations are the same as those in the sixth embodiment.

  As described above, according to the eighth embodiment, the transmission system of the transmission / reception sub-antennas 19 arranged in a distributed manner has the same function as in the fifth embodiment, and the reception system has the same function as in the first embodiment. Each is applied. Thereby, the effect of this Embodiment 8 combines the effect of these Embodiments.

  That is, in transmission, a transmission beam is synthesized in space as a means for increasing the transmission gain, so that simultaneous transmission at the same frequency is possible, and the modulator and demodulator in the seventh embodiment are not required, and the eigenvalue for reception One beamforming processor 4 is sufficient.

  Further, since there is no restriction that the directivity directions of the transmission beam and the reception beam are the same, the transmission beam and the reception beam can be formed in different directions depending on the purpose. Instead, unlike the seventh embodiment, position information of each transmission / reception sub-antenna 19 and prior information of phase error are required for the synthesis of transmission beams.

  On the other hand, in the reception, as in the seventh embodiment, the effects of improving the reception gain and widening the reception beam width can be obtained.

  In the eighth embodiment, an example in which all sub-antennas are configured to be able to transmit and receive is shown. However, the number of sub-antennas for transmission and reception is not necessarily the same, and these numbers are different. It is clear that the same effect is obtained in the case.

  Further, although the example in which the eighth embodiment is applied to the configuration of the first embodiment has been described, it is needless to say that the same effect can be obtained by applying to the second to fourth embodiments.

Embodiment 9 FIG.
In the ninth embodiment, when all the sub-antennas are transmission / reception sub-antennas and the directivity directions of the transmission beam and the reception beam are the same as those in the eighth embodiment, the weight calculation of the eigenvalue beamforming processor for transmission is performed. Instead, the weight calculated by the eigenvalue beamforming processor for reception is used for weight multiplication of the excitation signal. As a result, the amount of calculation is reduced from that in the eighth embodiment.

  FIG. 13 is a diagram showing a configuration of an antenna apparatus according to Embodiment 9 of the present invention. In the figure, a weight memory 24 stores a receiving weight that is a maximum eigenvalue vector calculated by the maximum eigenvector calculation unit 6. In addition, the same code | symbol is attached | subjected to the component which is the same as that of FIG.8 and FIG.9, or it corresponds, and the overlapping description is abbreviate | omitted.

Next, the operation will be described.
The maximum eigenvector calculation unit 6 in the reception eigenvalue beamforming processor 4 calculates the maximum eigenvalue vector for each transmission / reception sub-antenna 19 in the same manner as in the first embodiment. Here, the output of the maximum eigenvector calculation unit 6 is branched into two, one being output to the complex multiplication unit 7 in the own processor 4 and the other being output to the weight memory 24 in the transmission eigenvalue beamforming processor 15 for storage. Is done.

  As a result, the complex multiplier 7 in the reception eigenvalue beamforming processor 4 multiplies the received signal by using the maximum eigenvalue vector as a reception weight. Further, the complex multiplier 17 in the transmission eigenvalue beamforming processor 15 multiplies the transmission signal by the maximum eigenvalue vector temporarily stored in the weight memory 24 as a weight that is read out during the transmission process and multiplied by the excitation signal. Other processes are the same as those in the eighth embodiment.

Next, an outline of the ninth embodiment will be described.
In Embodiment 8, if all the sub-antennas are transmission / reception sub-antennas 19 and the directivity directions of the transmission beam and the reception beam are the same, the weights in the eigenvalue beamforming processors for reception and transmission are the same. become. Therefore, once the weight that maximizes the reception gain of the target wave source is determined by at least one reception, if this is used as the weight for the next transmission, the transmission gain for that wave source is the same as the reception gain. Maximized.

  For example, when the ninth embodiment is applied to a radar apparatus, if the received beam is synthesized with the received signal for the first transmission (in this case, transmission beam synthesis has not been performed yet), this weight is set to the second time. Transmission gain, thereby increasing the transmission gain. Therefore, after this, both transmission and reception have high gain, and stable target detection can be performed.

  As described above, according to the ninth embodiment, when all the sub-antennas are transmission / reception sub-antennas and the directivity directions of the transmission beam and the reception beam are the same, the same effect as in the eighth embodiment is obtained. It can be achieved with less computation.

  Unlike the configuration of the eighth embodiment, when the ninth embodiment is applied to the configuration of the first embodiment or the second embodiment, the positional information and phase error of each transmission / reception sub-antenna 19 There is also an advantage that no information is required.

  In addition, although the example which applies the said Embodiment 9 to the structure of the said Embodiment 1 was shown, it cannot be overemphasized that even if it applies to the said Embodiment 2 thru | or 4, it has the same effect.

It is a figure which shows the structure of the antenna apparatus by Embodiment 1 of this invention. It is a figure of the coordinate system which shows an element antenna position and a radio wave arrival direction. FIG. 6 is a diagram illustrating a composite pattern calculation example and a sub-antenna pattern according to the first embodiment. It is a figure which shows the structure of the antenna apparatus by Embodiment 2 of this invention. It is a figure which shows the example of calculation of the synthetic | combination pattern by Embodiment 2, and a subantenna pattern. It is a figure which shows the structure of the antenna apparatus by Embodiment 3 of this invention. It is a figure which shows the structure of the antenna apparatus by Embodiment 4 of this invention. It is a figure which shows the structure of the antenna apparatus by Embodiment 5 of this invention. It is a figure which shows the structure of the antenna apparatus by Embodiment 6 of this invention. It is a figure which shows the structure of the antenna apparatus by Embodiment 7 of this invention. FIG. 10 is a diagram for explaining a modulation process of a modulator according to a seventh embodiment. It is a figure which shows the structure of the antenna apparatus by Embodiment 8 of this invention. It is a figure which shows the structure of the antenna device by Embodiment 9 of this invention.

Explanation of symbols

1, 1-1 to 1-K reception sub-antennas, 2 integrated beam controller (integrated beam control unit), 3 receivers, 4 eigenvalue beam forming processor for reception (reception processing unit), 5 covariance matrix calculation unit (matrix Calculation unit), 6 maximum eigenvector calculation unit (vector calculation unit), 7, 17 complex multiplication unit (multiplication unit), 8 total calculation unit, 9 reception beam controller (beam control unit), 10 subantenna correction memory (correction memory) ), 11 Virtual wave source array response vector calculation unit (array response vector calculation unit), 12 array response vector memory, 13 transmission subantenna, 14 excitation signal generator, 15 eigenvalue beamforming processor for transmission (transmission processing unit), 16 signals Distribution unit, 18 transmitter, 19 transmission / reception sub-antenna, 20 transmission / reception switch (transmission / reception switching unit), 21 signal detector, 22 modulator Modulation processing unit), 23 a demodulator (demodulator), 24 weight memory.

Claims (9)

A plurality of receiving sub-antennas having distributed directional beams;
An integrated beam control unit for controlling a beam directing direction of the plurality of reception sub-antennas;
A receiver that receives a signal via the reception sub-antenna, a matrix calculation unit that calculates a covariance matrix of an output signal of the receiver, and a vector calculation unit that calculates an eigenvector corresponding to the maximum eigenvalue of the covariance matrix A reception processing unit including: a multiplication unit that multiplies the output signal of each receiver by using the eigenvector as a weight; and a summation calculation unit that calculates and outputs a sum of output signals of the receivers multiplied by the weight. Antenna device provided.   The transmission / reception sub-antenna capable of transmission / reception, a transmission / reception switching unit that switches between transmission and reception of the transmission / reception sub-antenna, and a transmitter that supplies a transmission signal to the transmission / reception sub-antenna. Antenna device. A plurality of transmission / reception sub-antennas capable of distributed transmission and reception;
A transmission / reception switching unit that switches between transmission and reception of the transmission / reception sub-antenna;
An integrated beam control unit that controls beam directing directions of the plurality of transmission / reception sub-antennas;
A receiver that receives a signal via the transmission / reception sub-antenna, a demodulation processing unit that demodulates an output signal of the receiver and separates it into a reception signal for each transmission / reception sub-antenna, and covariance of the output signal of the receiver A matrix calculator for calculating a matrix; a vector calculator for calculating an eigenvector corresponding to the maximum eigenvalue of the covariance matrix; a multiplier for multiplying the output signal of each receiver by using the eigenvector as a weight; and multiplying the weight A reception processing unit having a total calculation unit that calculates and outputs the sum of the output signals of each receiver,
An antenna apparatus comprising: a modulation processing unit that modulates an excitation signal by frequency division or time division according to the number of transmission / reception sub-antennas; and a transmitter that supplies the modulated excitation signal to the transmission / reception antenna as a transmission signal. A plurality of transmission / reception sub-antennas capable of transmission / reception distributed, and
A transmission / reception switching unit that switches between transmission and reception of the transmission / reception sub-antenna;
An integrated beam control unit that controls beam directing directions of the plurality of transmission / reception sub-antennas;
A receiver that receives a signal via the transmission / reception sub-antenna, a matrix calculation unit that calculates a covariance matrix of an output signal of the receiver, and a receiving side vector that calculates an eigenvector corresponding to the maximum eigenvalue of the covariance matrix A reception unit comprising: a calculation unit; a reception side multiplication unit that multiplies the output signal of each receiver by using the eigenvector as a weight; and a total calculation unit that calculates and outputs the sum of the output signals of each receiver multiplied by the weight A processing unit;
A correction memory for storing information on the position and phase error of each of the transmission / reception sub-antennas, a virtual memory based on the information stored in the correction memory and the beam directing directions of the plurality of transmission / reception sub-antennas controlled by the integrated beam control unit An array response vector calculation unit that calculates an array response vector in the direction of the wave source, a matrix calculation unit that calculates a covariance matrix corresponding to the virtual wave source using the array response vector, and a maximum eigenvalue of the covariance matrix A transmission-side vector calculation unit for calculating eigenvectors; a transmission-side multiplication unit for multiplying the excitation signals distributed to the number of transmission / reception antennas by using the eigenvectors as weights; and the transmission / reception units using the excitation signals multiplied by the weights as transmission signals An antenna device having a transmitter for supplying to a sub-antenna and a transmission processing unit having the transmitter . A plurality of transmission / reception sub-antennas capable of transmission / reception distributed, and
A transmission / reception switching unit that switches between transmission and reception of the transmission / reception sub-antenna;
An integrated beam control unit that controls beam directing directions of the plurality of transmission / reception sub-antennas;
A receiver that receives a signal via the transmission / reception sub-antenna, a matrix calculation unit that calculates a covariance matrix of an output signal of the receiver, and a receiving side vector that calculates an eigenvector corresponding to the maximum eigenvalue of the covariance matrix A reception unit comprising: a calculation unit; a reception side multiplication unit that multiplies the output signal of each receiver by using the eigenvector as a weight; and a total calculation unit that calculates and outputs the sum of the output signals of each receiver multiplied by the weight A processing unit;
A transmission side multiplication unit that multiplies the excitation signal distributed to the number of transmission / reception antennas by the eigenvector calculated by the reception side vector calculation unit as a weight, and an excitation signal multiplied by the weight as a transmission signal to each transmission / reception sub-antenna. An antenna apparatus comprising: a transmission processing unit having a transmitter to be supplied.   The sub-antenna is an antenna having a different antenna pattern, and a beam controller for controlling a beam directing direction for each sub-antenna is provided. Antenna device. The reception processing unit includes a correction memory for storing information on the position and phase error of each sub-antenna measured in advance, information stored in the correction memory, and beams of the plurality of sub-antennas controlled by the integrated beam control unit. An array response vector calculation unit that calculates an array response vector of the virtual wave source direction based on the pointing direction,
The antenna apparatus according to claim 1, wherein the matrix calculation unit calculates a covariance matrix using the array response vector. The reception processing unit includes an array response vector memory that stores an array response vector obtained by measuring an output signal of the receiver with respect to a wave source in a known direction, and a beam directing direction of the plurality of sub-antennas controlled by the integrated beam control unit An array response vector calculation unit for obtaining array response vectors in a plurality of virtual wave source directions by interpolation calculation of the array response vectors stored in the array response vector memory,
The antenna apparatus according to claim 1, wherein the matrix calculation unit calculates a covariance matrix using the array response vector. A plurality of transmitting sub-antennas having distributed directional beams;
An integrated beam control unit that controls the beam directing directions of the plurality of transmission sub-antennas to be the same direction;
A correction memory for storing information on the position and phase error of each transmission sub-antenna;
An array response vector calculation unit that calculates an array response vector in a virtual wave source direction based on information stored in the correction memory and a beam directing direction of the plurality of transmission sub-antennas controlled by an integrated beam control unit;
A matrix calculation unit that calculates a covariance matrix corresponding to the virtual wave source using the array response vector calculated by the array response vector calculation unit;
A vector calculation unit for calculating an eigenvector corresponding to the maximum eigenvalue of the covariance matrix;
A multiplier for multiplying the excitation signal distributed to the number of transmission sub-antennas with the eigenvector as a weight;
An antenna apparatus comprising: a transmitter that supplies an excitation signal multiplied by the weight as a transmission signal to each transmission sub-antenna.

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