JP5351466B2 - Radio source visualization device - Google Patents

Description

  The present invention relates to a radio wave source visualization apparatus for identifying and visualizing radio wave sources.

Conventionally, as a technique for specifying a radio wave leakage position or the like as a radio wave source, for example, a technique for estimating a radio wave wave source position leaking from an electronic device (see Patent Document 1), or a technique for exploring a radiation interference wave (Patent Document 2) And a technique (see Patent Document 3) for specifying a leaky wave source position in an electromagnetic wave shield is known.
JP 2005-195532 A JP 2001-194399 A JP 2004-205404 A

  In Patent Document 1, the position is estimated using a technique called an extended SPM (Sampled Pattern Matching) method. However, since the distance between the radio wave source and the antenna is limited to 2 to 5λ (λ: wavelength of the measurement frequency), for example, in the case of a wireless LAN (Local Area Network) exceeding 2 GHz, the distance is about 60 cm at the maximum. Only a radio wave source in a certain range can specify its position.

  In Patent Document 2, only the amplitude is measured using an internationally standardized CISPR (International Radio Interference Special Committee) measurement system, and the source position of the radiated disturbance source and the direction of the source are estimated. Yes. However, the technique described in Patent Document 2 calculates a correction value each time and repeats until the correction value converges, so that it takes time to converge.

  In Patent Document 3, the radio wave arrival direction and the distance to the radio wave source are obtained, and the position of the radio wave source is specified. Therefore, it is necessary to measure the distance to the radio wave source. However, when measuring leaked radio waves from a shielded room at a construction site, etc., if the installation location of the measuring device is changed frequently, the position to the radio wave source must be measured each time. The burden to be applied becomes significant. Even if the direction of arrival of radio waves can be specified, it is often impossible to accurately measure the distance. In such a case, the position of the radio wave source cannot be specified accurately.

  Accordingly, the present inventor has developed a radio wave source specifying system that can accurately specify the position of the radio wave source even if the distance to the radio wave source is unknown (Japanese Patent Application No. 2007-130068). The radio wave source identifying system is configured to determine a center position at a plurality of positions to which the antenna is moved based on one antenna, an imaging device for imaging a measurement direction, and the phase and amplitude of an incoming radio wave received by the antenna. A radio wave arrival direction specifying means for specifying a radio wave source by an angle in a polar coordinate space as an origin, and a plurality of antenna holders for holding the antenna at set intervals, and the imaging device as the origin An angle indicating the radio wave arrival direction specified by the radio wave arrival direction specifying means by associating the template in which the imaging device holding unit is held with each pixel of the image captured by the imaging device with an angle in the polar coordinate space. Radio wave source position presenting means for distinguishing and presenting the pixels corresponding to the above in the image. According to such a radio wave source identification system, one antenna is installed in order at each installation place where each antenna holding unit is formed, and radio waves of incoming frequencies are received. The angle in the polar coordinate space can be specified based on, and the direction specified by the angle can be specified as the radio wave arrival direction. By changing the installation position of one antenna sequentially, it functions as an array antenna. In addition, the angle of the specified radio wave arrival direction can be presented in the image captured by the imaging device, so even if the distance to the radio wave source is unknown, the radio wave source exists at any position in the image. You can show what to do. Thereby, the worker can grasp the position of the radio wave source while viewing the image.

  However, in the radio wave source specifying system, when the radio wave source is visualized using the wide band antenna, it is unclear at which element position of the wide band antenna the radio wave is received. Therefore, in the process of visualizing the radio wave source, it is difficult to accurately match the position of the receiving element (hereinafter sometimes referred to as a reference point) and the position of the camera lens. As a result, when a radio wave source is visualized using a broadband antenna, there is a problem in that the estimation accuracy is not very good because the reference point is slightly different depending on the frequency.

  Further, in the measurement using the template, since the measurement is sequentially performed by moving the antenna, it takes about 10 minutes for one measurement. In this case, there is no problem in receiving and measuring the radiated radio wave, but in a situation where the radio signal changes or the surrounding environment changes over time, the measurement should be made accurately. There is also a problem that is difficult.

  Accordingly, the present invention has been devised to solve the above-described problem, and an object thereof is to provide a radio wave source visualization device that has a clear antenna reference point, is compact, and can reduce measurement time. To do.

In order to solve the above-mentioned problem, the invention according to claim 1 is a radio wave source visualization device for identifying and visualizing a radio wave source, an imaging device for imaging a radio wave source measurement target region, and the imaging device Is an array antenna formed by arranging a plurality of planar antennas on a substrate with a central position, and the arrival direction of incoming radio waves received by the array antenna is only an angle in a polar coordinate space with the imaging unit of the imaging device as the origin the radio wave arrival direction specifying means for specifying by the real image captured by the imaging device, wherein by combining the radio wave image data showing the radio wave arrival direction identified by the radio wave arrival direction specifying means, in said real image and a radio source location indicating means for identifying the radio source to display the DOA, the imaging apparatus, the focus of the lens is flush with the surface of the substrate Are fitted to the through hole of the substrate so that, the radio source location indicating means, said radio wave arrival to the number of pixels for the field angle and the unit angle calculated from the number of pixels of the real image of the imaging device The radio wave source visualization apparatus is characterized in that a pixel corresponding to the radio wave arrival direction is obtained by corresponding a direction angle, and the pixel is distinguished and displayed in the actual image .

  According to the radio wave source visualization apparatus having such a configuration, the planar direction is thinned by providing the planar antenna on the surface of the substrate, so that the reference point at which the radio wave is received becomes clear. As a result, the reference point and the position of the photographing apparatus can be made to coincide with each other, so that the radio wave source identification accuracy can be improved. In addition, the entire system can be made compact. Furthermore, since the array antenna is formed by arranging a plurality of planar antennas, radio waves can be received collectively by the plurality of planar antennas, and the measurement time can be greatly shortened. In addition to this, it is possible to reduce the influence of the radio wave signal that fluctuates with time and the surrounding environment, and it is possible to increase the measurement accuracy.

  The invention according to claim 2 is characterized in that the plurality of planar antennas are arranged in the vertical and horizontal directions, and the number of arrangements in at least one of the vertical and horizontal directions is an even number. Radio wave source visualization device.

  Note that the arrangement in the vertical and horizontal directions means arrangement in the vertical and horizontal directions in accordance with the intersection positions of the grids. According to the radio wave source visualization device having such a configuration, since the planar antenna is not located at the center portion of the array antenna, the imaging device can be installed at that position. Therefore, the origin of the polar coordinate space can be the central part of the installation area of the planar antenna, and as a result, the direction of radio wave arrival can be easily identified.

  The invention according to claim 3 is the radio wave source visualization device according to claim 1 or 2, wherein the photographing device is equipped with a wide-angle lens.

  According to the radio wave source visualization apparatus having such a configuration, it is possible to take an image of a wider radio wave source measurement target area.

  According to the present invention, the antenna reference point is clarified, the apparatus can be made compact, and the excellent effect that the measurement time can be shortened is exhibited.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the best mode for implementing the radio wave source visualization device 1 according to the present invention will be described with reference to FIG.

  As shown in FIGS. 1 to 3, the radio wave source visualization device 1 (see FIG. 1) according to the present embodiment is a system for identifying and visualizing radio wave sources. A through hole 11 is formed for fitting a photographing device 20 for photographing a region. On the surface 10 a of the substrate 10, a plurality of planar antennas 30, 30... Are arranged so as to surround the through hole 11, thereby forming an array antenna 31. A ground plane 40 is provided on the back side of the plurality of planar antennas 30, 30. An imaging device 20 is fitted in the through hole 11. Further, the arrival of radio waves specifying the arrival directions of the incoming radio waves respectively received by the plurality of planar antennas 30, 30... By the angle in the polar coordinate space with the focal point (imaging unit) of the lens 21 of the imaging device 20 as the origin O. Direction specifying means 51 (see FIG. 1) is connected to each of the on-surface antennas 30, 30,. The radio wave image data indicating the radio wave arrival direction specified by the radio wave arrival direction specifying unit 51 is synthesized with the real image taken by the imaging device 20, and the radio wave arrival direction is displayed in the real image to specify the radio wave source. Radio wave source position presenting means 52 (see FIG. 1) is connected to the photographing apparatus 20.

  As shown in FIG. 1, the substrate 10 is detachably supported by a support frame 61 formed on the traveling carriage 60 and is supported in a vertically standing state. As shown in FIG. 3, the substrate 10 is made of a square plate plate material made of glass epoxy. A through hole 11 for fitting the photographing device 20 is formed at the intersection of the two diagonal lines of the substrate 10 (central portion of the substrate 10). The through-hole 11 has an inner shape that is the same as the outer shape of the camera that constitutes the photographing apparatus 20, and is adapted to be fitted and fixed to the camera. Further, as shown in FIG. 4A, the through-hole 11 is configured so that the focal portion of the lens 21 (the same position as the origin O) is positioned substantially in the same plane as the surface 10 a of the substrate 10. 20 is held. Here, since the distance between the surface of the lens 21 and the imaging unit is about several millimeters and is a negligible distance compared to the incoming radio wave measurement distance of several meters or more, the surface of the lens 21 is the surface of the substrate 10. Even if the camera is fitted so as to be in the same plane as 10a, it can be assumed that the focal portion of the lens 21 is substantially located in the same plane as the surface 10a of the substrate 10.

  As shown in FIGS. 2 and 3, the planar antenna 30 arranged on the surface 10 a of the substrate 10 is a patch formed by, for example, attaching a copper plate to the surface 10 a of the substrate 10 and etching elements on the surface. It consists of an antenna. The patch antenna has a narrow band and wide directivity. The plurality of planar antennas 30, 30... Are each formed in a square plate shape having the same dimensions when viewed from the front. Each planar antenna 30 has a coaxial cable 32 connected to the back surface thereof via a power supply 33. Each planar antenna 30 is electrically connected to a control personal computer 50 having radio wave arrival direction specifying means 51 via a coaxial cable 32. A cable insertion hole 12 (see FIG. 2) through which the coaxial cable 32 is inserted is formed in the substrate 10 so as to penetrate from the front surface 10a to the back surface 10b.

  The planar antennas 30, 30... Are arranged at intersections of grids in the vertical and horizontal directions, and the number of arrangements in at least one of the vertical and horizontal directions is an even number. In this embodiment, as shown in FIG. 3, the planar antennas 30, 30... Are configured to be arranged in four rows and four columns at equal intervals in both the vertical direction and the horizontal direction. And the through-hole 11 is formed in the center position. That is, the through hole 11 is positioned at the center of the antenna region of the array antenna 31 constituted by the plurality of planar antennas 30, 30. In the present embodiment, the position of the through hole 11 is the central portion of the substrate 10, but the present invention is not limited to this. The through hole 11 only needs to be positioned at the center of the antenna area of the array antenna 31. When the center of the antenna area of the array antenna 31 is shifted from the center of the substrate 10, the through hole 11 also has the antenna area. Shift to the center of the.

  As shown in Table 1 below, the dimension L1 (see FIG. 3) of one side of the planar antenna 30, the thickness, and the interval L2 (see FIG. 3) between the adjacent planar antennas 30 and 30 are received. It is set appropriately according to the frequency of the radio wave. The numerical values in Table 1 are calculated using a FDTD (Finite-difference time-domain method) method.

  As shown in Table 1, for example, when the frequency of the received radio wave is 1.5 GHz, the dimension (element size) L1 of one side of the planar antenna 30 is 48.3 mm, the thickness is 1.6 mm, The relative dielectric constant is 4.4. Further, the distance L2 between the adjacent planar antennas 30 and 30 is 100 mm. The higher the frequency of the received radio wave, the smaller the dimension L1 on one side of the planar antenna 30, and the smaller the feed interval L2 between the planar antennas 30,30.

  According to the frequency of the radio wave to be received, the size and thickness of the planar antenna 30 shown in Table 1 and the distance between the feeds of the planar antennas 30 and 30 are applied, so that the planar antennas 30, 30. A plurality of array antennas 31 are respectively formed on a plurality of substrates 10.

  As shown in FIGS. 1 and 2, the ground plate 40 provided on the back side of the plurality of planar antennas 30, 30... Is made of, for example, a copper plate in this embodiment, and is formed on the back surface 10 b of the substrate 10. It is affixed and grounded. In the base plate 40, a camera insertion hole 41 is formed at a position corresponding to the through hole 11 of the substrate 10, and a cable insertion hole 43 is formed at a position corresponding to the cable insertion hole 12 of the base 10.

  As shown in FIG. 1, the radio wave arrival direction specifying means 51 and the radio wave source position presentation means 52 are provided in a control personal computer (PC) 50 connected to each planar antenna 30 and the imaging device 20. Each planar antenna 30 is connected to a control personal computer 50 via a preamplifier 55 and a measuring device 56.

  The preamplifier 55 amplifies the reception signal received by each planar antenna 30 and outputs the amplified reception signal to the measuring device 56 via the coaxial cable 53. However, when the input voltage of the received signal received by the planar antenna 30 is high, the preamplifier 55 is not necessary.

  The measurement device 56 includes signal analysis means (not shown) for analyzing the received signal and detecting the amplitude of the waveform and the phase of the waveform of the adjacent planar antenna 30, and outputs from each planar antenna 30. The amplitude and phase of the received signal are detected.

  The control personal computer 50 mainly includes an interface (not shown) such as a CPU (Central Processing Unit), a memory, an HDD (Hard Disk Drive), a display, and a GPIB (General Purpose Interface Bus). The personal computer for control 50 functions as a radio wave arrival direction specifying unit 51 and a radio wave source position presentation unit 52 when the CPU executes a predetermined program. Note that the control personal computer 50 and the measurement device 56 are connected to each other via a GPIB cable 54 so that data communication is possible.

  The radio wave arrival direction specifying means 51 is based on the amplitude and phase of the received signal analyzed by the measuring device 56 and the installation position of each planar antenna 30, for example, according to the MUSIC (MUltiple SIgnal Classification) algorithm. , The arrival direction of the radio wave source is specified by the angle (θ, φ) in the polar coordinate space (Θ, Φ) with the mounting position of the photographing device 20 (center position in the antenna area of the array antenna 31) as the origin O. (See FIG. 4).

  Here, the polar coordinate space used in this embodiment will be described with reference to FIG. 4 (a) and (b) in FIG. 4 with the imaging unit (focal part of the lens 21) of the imaging device 20 at the substantially same position as the center position of the array antenna 31 (see FIG. 3) as the origin O. ). That is, of the xyz axes in the polar coordinate space, the x axis is substantially located on the surface 10a of the substrate 10 and extends laterally from the origin O, and the y axis is substantially located on the surface 10a of the substrate 10. The z-axis extends from the origin O in the direction perpendicular to the surface 10a of the substrate 10 (the axial direction of the imaging device 20).

  As shown in FIG. 4 (b), when a perpendicular is extended from a point P on the line indicating the arrival direction of the received radio wave to the xy plane that constructs the xyz orthogonal coordinate system, the intersection of the perpendicular and the xy plane is Q. An angle formed by a straight line OQ connecting the origin O and the intersection point Q (orthographic projection of the arrival direction onto the xy plane) and the x axis is φ. On the other hand, an angle formed between a straight line OP connecting an arbitrary point P in the arrival direction of the received radio wave and the origin O and the z axis is θ. The direction of arrival of the received radio wave can be expressed as coordinates in a polar coordinate space having the angle θ and the angle φ as components.

  The radio wave source position presentation unit 52 associates an angle in the polar coordinate space with each pixel of the image captured by the imaging device 20, and sets a pixel corresponding to the angle indicating the radio wave arrival direction specified by the radio wave arrival direction specifying unit 51. The images are distinguished (displayed) on a display (not shown). That is, the radio wave source position presentation unit 52 sets the angle (θ, φ) of the specified radio wave arrival direction within the angle of view (Θ, φ) of the actual image of the radio wave source measurement target region α photographed by the photographing device 20. This is displayed on the display in correspondence with the pixels.

  Therefore, the relationship between the angle of view (Θ, Φ) and the angle (θ, φ) is preset in the radio wave source position presentation unit 52. That relationship is the number of pixels with respect to the unit angle of view angle.

  For example, when the angle of view of the CCD used as the photographing device 20 is the photographing device 20 of Θ (vertical direction) = 67 deg to 112 deg (45 deg) and Φ (horizontal direction) = 60 deg to 120 deg (60 deg), 90 deg for both θ and φ is the front direction of the imaging device 20 and the through hole 11 (see FIG. 4A). In FIG. 4A, the field angle in the horizontal direction is illustrated, and the field angle in the vertical direction is only a numerical value written in parentheses. In the range of the angle of view, when each unit angle is 1 deg, it can be expressed as Θ-Φ space of 45 scales in Θ (vertical direction) and 60 scales in Φ (horizontal direction). Therefore, when the number of pixels of the CCD used as the photographing device 20 is 720 pixels × 960 pixels, the number of pixels with respect to the unit angle of view angle is indicated as θ = 16 pixels / deg and φ = 16 pixels / deg.

  As a result, the angle (θ, φ) of the arrival direction as the estimation result is indicated as the pixel spread in the image data. Therefore, it becomes possible to present on the display as the existence range of the leaked portion.

  With the above operation, the field angle (Θ, Φ) and the estimation result (θ, φ) can be made to correspond to each other. Therefore, the radio wave source position presentation unit 52 sets the radio wave arrival direction on the actual image captured by the imaging device 20. The shown radio wave image data can be synthesized and presented on the display. At this time, the position of the radio wave source is displayed separately by changing the color or brightness of the portion or by marking it with a line or a figure. In this embodiment, in order to make the position of the radio wave source easy to understand, only the peak part of the estimation result is extracted and combined. However, by processing the part other than the peak in the same manner, It is also possible to present the surrounding situation.

  Therefore, according to this embodiment, when the polar coordinate space is a coordinate system, even if the distance to the radio wave source of the incoming wave is unknown, the actual image G1 (see FIG. 5) captured by the imaging device 20 7 is synthesized with the radio wave image data (see FIG. 6) indicating the radio wave arrival direction (illustrated as the leakage position S), and the arrival direction is displayed, as shown in FIG. 7, in the photographed real image G1. The position of the radio wave source (leakage position S) can be displayed and specified. That is, as shown in FIG. 4A, the shooting angle of view of the imaging device 20 fitted in the through hole 11 is indicated by (Θ, Φ), so that it is estimated as the arrival direction within the range. By specifying the pixel corresponding to the result (θ, φ), the position in the image can be specified.

  Note that a wide-angle lens may be attached to the photographing apparatus 20 for the purpose of photographing and evaluating a wide range at a time. In this case, the relationship between the angle of view (Θ, Φ) and the angle (θ, φ) is preset in the radio wave source position presentation unit 52. In other words, since the image acquired by the wide-angle lens has a property of being distorted toward the end of the image, the relationship between the angle of view (Θ, Φ) and the angle (θ, φ) cannot be obtained uniformly. For example, an image of a paper on which a square grid of 2 cm square is printed in advance is obtained, and an angle (θ, φ) is calculated for each intersection of the grids in the image, which corresponds to each angle of view (Θ, Φ) of the intersection. The angles (θ, φ) are set in advance. As a result, the angles (θ, φ) are assigned to all the angles of view (Θ, Φ). That is, the image acquired using the wide-angle lens is not corrected, and the arrival direction is specified in consideration of the distorted angle.

  As shown in FIG. 1, the control personal computer 50 (including the radio wave arrival direction specifying means 51 and the radio wave source position presentation means 52), the preamplifier 55 and the measuring device 56 are arranged on the back side of the substrate 10 on the traveling carriage 60. Has been.

  Next, an operation / processing procedure in the case of specifying a radio wave source using the radio wave source visualization device 1 having the above configuration will be described.

  In the present embodiment, a case will be described in which the radio wave source visualization apparatus 1 measures / discovers leakage of radio waves from the radio wave generation room R1 in which radio wave generation equipment exists.

  First, as shown in FIG. 1, the radio wave source visualization device 1 is installed in a measurement chamber R2 that measures a radio wave source. The substrate 10 of the radio wave source visualization device 1 is installed so as to face the radio wave source measurement target region α that forms a part of the wall W located between the radio wave generation chamber R1.

  Next, the measurement region is photographed by the photographing device 20 fitted in the through hole 11 of the substrate 10, and the photographed image (image) is displayed on a display (not shown) of the control personal computer 50. The measurer determines the measurement region while viewing the image. That is, the direction of the imaging device 20 is changed by moving the radio wave source visualization device 1 together with the traveling carriage 60 so that the orientation of the imaging device 20 faces a desired measurement region (for example, the radio wave source measurement target region α). Determine the orientation. At this time, the image photographed by the photographing apparatus 20 is sent to the control personal computer 50 and stored therein.

  Thereafter, radio wave reception by each planar antenna 30 is started. When the radio wave from the radio wave generation chamber R1 passes through the wall W and leaks, the transmitted radio wave is received by the planar antenna 30, and the leakage location is measured as a radio wave source.

  At this time, since the reception of radio waves can be performed collectively with the planar antennas 30, 30... Arranged at predetermined positions, an antenna is installed on the antenna holding portion of the template as in the past. Compared with a measuring apparatus that measures one by one, the measuring time can be greatly shortened. And since measurement time becomes short, the influence by the signal of the radio wave which fluctuated temporally and the surrounding environment can be reduced, and measurement accuracy can be raised. Furthermore, unlike the conventional measuring apparatus, the operator does not have to move the antenna along the template, so that the work time and labor can be reduced, and the antenna position accuracy is not lowered and the measurement accuracy is prevented from being lowered. .

  The radio wave received by each planar antenna 30 is sent to the preamplifier 55 as a reception signal, amplified by the preamplifier 55, and then sent to the measuring device 56. The measuring device 56 analyzes the amplitude and phase of the radio wave received by each planar antenna 30 based on the received signal. The obtained amplitude and phase data is sent to the control personal computer 50 together with the received signal.

  The control personal computer 50 receives received signals and data from the measuring device 56 and accumulates them in a storage unit (not shown). Thereafter, the personal computer for control 50 uses the MUSIC algorithm or the like by the radio wave arrival direction specifying means 51 to specify the radio wave arrival direction.

  As described above, the radio wave source position presentation unit 52 specifies the pixel of the display (not shown) based on the number of pixels with respect to the unit angle of the view angle, and the angle of the arrival direction obtained by the radio wave arrival direction specifying unit 51. Then, the radio wave source position presentation unit 52 synthesizes radio wave image data indicating the radio wave arrival direction (see the leaked position S in FIG. 6) with the actual image G1 (see FIG. 5) captured by the imaging device 20. Thus, the pixels in the radio wave arrival direction are displayed in the real image G1 so as to be distinguishable from other parts (see the leakage position S part in FIG. 7). As a result, the measurer can specify the radio wave source position (leakage position S) in the image while viewing the image. Note that when radio waves are not leaked, no distinction is displayed in the actual image G1.

  By the way, in this embodiment, by providing the planar antennas 30, 30... On the surface 10 a of the substrate 10, the depth direction of the antenna becomes thin and the reference point at which the radio wave is received becomes clear. In addition, the photographing apparatus 20 is held in the through hole 11 so that the surface of the lens 21 is positioned substantially on the same plane as the surface 10 a of the substrate 10. Therefore, the reference point and the depth direction position of the imaging device 20 can be matched. As a result, as shown in FIG. 4A, the center position of the array antenna 31 (see FIG. 3) and the origin O of the imaging range (display range) of the imaging device 20 can be matched. This makes it possible to accurately associate the shooting angle of the actual image captured by the imaging device 20 with the angle of the radio wave arrival direction specified by the radio wave arrival direction specifying means 51, so that the radio image data is added to the actual image. When synthesized, the radio wave source can be accurately specified and displayed in the actual image.

  Moreover, according to this embodiment, since the ground plane 40 is provided on the back surface 10b (the back surface side of the planar antenna 30) of the substrate 10, the sensitivity is good only in the front in the orthogonal direction of the planar antenna 30. That is, since the radio wave from behind can be blocked by the ground plane 40, even if measuring devices (control personal computer 50, preamplifier 55 and measuring device 56) are arranged behind, they are not affected by these measuring devices. Can receive radio waves. Therefore, it is possible to prevent a decrease in measurement accuracy. Furthermore, the wiring connecting the measuring devices can be shortened, the entire system can be made compact, and the radio wave source visualization device 1 can be moved integrally.

  In the above-described embodiment, the case where the location where the radio wave in the radio wave generation chamber R1 leaks from the radio wave source measurement target area α of the wall W has been described. However, as shown in FIG. The reflection of the radio wave from the generated radio wave source 2 on the wall surface can also be used as a radio wave source.

  In this case, the position of the angle of the radio wave arrival direction specified by the radio wave arrival direction specifying means 51 (see FIG. 1) is specified in the actual image taken by the imaging device 20, and the radio wave source Radio wave image data indicating the radio wave arrival direction (reflection position T) is combined with the real image G2 (see FIG. 9) captured by the imaging device 20 by the position presentation unit 52 (see FIG. 1), and the real image G2 The pixels in the radio wave arrival direction (reflection position T) are displayed so that they can be distinguished from other parts (see FIG. 10). As a result, the radio wave reflection position T on the wall, ceiling, joinery, etc. can be accurately and easily specified for each frequency, so that a radio wave absorber or the like can be accurately installed at a specific location such as a wall. become. As a result, it is possible to prevent the deterioration of communication performance by removing the influence of multipath in communication such as wireless LAN and RFID in the room.

  Furthermore, if the radio wave source visualization device 1 is used, reflection of radio waves can be specified as a radio wave source not only indoors but also outdoors. Therefore, for example, in order to prevent ETC (Electronic Toll Collection system) radio wave reception malfunctions at expressway interchanges, it is possible to identify radio wave sources around toll gates and investigate the flow of radio waves. is there.

  The embodiment according to the present invention has been described above. However, the present invention is not limited to this, and can be appropriately changed without departing from the spirit of the present invention. For example, in the above-described embodiment, the through-hole 11 serving as the mounting position of the imaging device 20 is located at the center of the antenna area of the array antenna 31, but is not limited to this, and is displaced from the center. It may be a different position. In this case, the origin of the polar coordinate space when the radio wave arrival direction specifying means 51 specifies the radio wave arrival direction is also shifted to the mounting position of the photographing apparatus 20, and the radio wave arrival direction is specified by the angle in the polar coordinate space corresponding to this origin. .

  In the above-described embodiment, the MUSIC algorithm has been described as the arrival direction specifying algorithm using the array antenna 31. However, the algorithm is not limited to this algorithm as long as the arrival direction can be specified. For example, a beamformer method, Capon method, linear prediction method, minimum norm method, or ESPRIT (Estimation of Signal Parameters via Rotational Invariance Techniques) algorithm may be used.

It is the block diagram which showed the best form for implementing the radio wave source visualization apparatus which concerns on this invention. It is sectional drawing which showed the board | substrate, the planar antenna, the imaging device, and the ground plane. It is the front view which showed the board | substrate, the planar antenna, and the imaging device. (A) is sectional drawing for demonstrating an imaging device, (b) is a figure explaining polar coordinate space. It is the figure which showed the real image image | photographed with the imaging device. It is the figure which imaged the radio wave image data which showed the radio wave arrival direction specified by the radio wave arrival direction specification means. It is the figure which made the real image synthesize | combine the radio wave image data which showed the radio wave arrival direction. It is the top view which showed the state which installed the radio wave source and the radio wave source visualization apparatus in the same room. It is the figure which showed the real image image | photographed with the imaging device. It is the figure which made the real image synthesize | combine the radio wave image data which showed the radio wave arrival direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radio wave source visualization apparatus 20 Imaging device 30 Planar antenna 31 Array antenna 51 Radio wave arrival direction specification means 52 Radio wave source position presentation means O Origin G1 Actual image

Claims (3)

A radio wave source visualization device for identifying and visualizing radio wave sources,
An imaging device for imaging a radio wave source measurement target area;
An array antenna formed by arranging a plurality of planar antennas on a substrate with the photographing apparatus as a central position;
Radio wave arrival direction specifying means for specifying the arrival direction of incoming radio waves received by the array antenna only by an angle in a polar coordinate space with the imaging unit of the imaging device as an origin;
The radio wave image data indicating the radio wave arrival direction specified by the radio wave arrival direction specifying unit is combined with the real image taken by the imaging device, and the radio wave arrival direction is displayed in the real image to display the radio wave. Radio wave source position presentation means for identifying the source,
The imaging device is fitted in the through hole of the substrate so that the focal point of the lens is flush with the surface of the substrate,
The radio wave source position presenting means associates the angle of the radio wave arrival direction with the number of pixels with respect to a unit angle calculated from the angle of view of the photographing apparatus and the number of pixels of the actual image , and corresponds to the radio wave arrival direction. The radio wave source visualization device, wherein the pixel is distinguished and displayed in the actual image . The radio wave source visualization device according to claim 1, wherein the plurality of planar antennas are arranged in the vertical and horizontal directions, and the number of arrangements in at least one of the vertical and horizontal directions is an even number. The radio wave source visualization device according to claim 1, wherein the photographing device is equipped with a wide-angle lens.

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