JP7300654B2 - Radio wave shielding loss calculation method, radio wave shielding loss calculation device, and radio wave shielding loss calculation program - Google Patents

Description

The present invention relates to a technique for calculating radio wave shielding loss due to shielding objects in radio wave propagation.

2. Description of the Related Art In radio wave communication systems, the radio wave intensity at a receiver that receives radio waves is affected by obstacles present on the path of radio wave propagation. In particular, radio waves with high frequencies and short wavelengths are weakly diffractive and suffer large propagation loss (radio wave shielding loss) due to shielding objects. On the other hand, in order to be able to communicate a large amount of information more quickly, there is a demand for a communication system (for example, a 5th generation mobile communication system) that uses a higher frequency radio wave for communication.

Therefore, in constructing a communication system, it is becoming more and more important to predictively calculate the radio wave shielding loss from the information of a transmitter that emits radio waves, a receiver that receives radio waves, and shielding objects. As for the method of calculating the radio wave shielding loss, various techniques have been proposed and studied.

Non-Patent Document 1 describes the results of studies on calculation of radio wave shielding loss based on a Knife-Edge Diffraction Model (KEDM) and a Physical Optics approximation (PO) method. In this study, when a shielding object (metallic object or person) is installed at a specific distance between the transmitter and the receiver, the radio wave shielding loss based on the KEDM and the PO method is calculated, and the actual radio wave shielding loss is calculated. are compared with the measurement results of As a result of the study, it has been found that the calculation of radio wave shielding loss based on the PO method is suitable for shields with complicated shapes.

Non-Patent Document 3 discloses a method of calculating radio wave shielding loss due to a knife-edge shield in radio wave propagation of high-frequency radio waves. The method works by creating a nomogram that gives radio shielding loss from the distance between the transmitter and the knife edge shield, the height of the knife edge shield, and the frequency of the radio waves. In addition, when there are multiple knife-edge shields on the path of radio wave propagation, a straight line connecting the transmitter and the receiver, a straight line from the transmitter looking at the tip of the knife-edge shield, and a straight line from the receiver to the knife-edge shield It is shown that the radio wave shielding loss can be given without a large error by giving a knife-edge shield whose tip is a triangular vertex obtained by a straight line looking at the tip of .

In addition, there is the following non-patent document 2 as a document showing the technical level of this technical field.

Xin DU, Kentaro Saito, Jun-ichi Takada, Mitsuki Nakamura, Motoharu Sasaki, Yasushi Takatori, “Shadowing Effect Prediction based on Physical Optics Approach for Millimetre Wave Mobile Communication”, IEICE technical report vol. 118, no. 504 , AP2018-192, pp. 35-40, March 2019 Xin DU, Kentaro Saito, Junichi Takada, Mitsutaka Nakamura, Nobuaki Kuno, Wataru Yamada, Taiji Takatori, ``Experimental and Prediction Method of Line-of-sight Wave Shielding Loss in Millimeter-wave Band Propagation'', The Institute of Electronics, Information and Communication Engineers Society Conference B-1-30 , September 2019 K. Bullington, “Radio Propagation at Frequencies above 30 Megacycles”, Published in: Proceedings of the IRE, vol. 35 , Issue. 10, pp. 1122 - 1136, Oct. 1947

As mentioned in Non-Patent Document 1, the conventional radio wave shielding loss calculation method based on the PO method is suitable for calculating the radio wave shielding loss due to a shield having a complicated shape. However, in the conventional method of calculating the radio wave shielding loss based on the PO method, calculation is performed using a thin screen as a shield.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a radio wave shielding loss calculation method and a radio wave shielding loss that enable calculation of the radio wave shielding loss with high accuracy even when the thickness of the shielding object is large. It is to provide a calculation device and a radio wave shielding loss calculation program.

A radio wave shielding loss calculation method according to an aspect of the present invention is a method of calculating a radio wave shielding loss caused by a shield present on a radio wave propagation path between a transmitter that emits radio waves and a receiver that receives radio waves. . This radio wave shielding loss calculation method consists of a plurality of straight lines extending radially from the transmitting point and passing through points on the outline of the shield seen from the transmitting point, and an equivalent screen calculation step of calculating the positions of intersections with a plurality of straight lines passing through a point and calculating an equivalent screen area, which is a planar area having a set of intersections as an outline; and a radio wave shielding loss calculation step of calculating the shielding loss.

Here, the transmission point is a position where the transmitter radiates radio waves. A receiving point is a position at which the receiver receives radio waves.

Further, a radio wave shielding loss calculation device according to an aspect of the present invention is a device for calculating radio wave shielding loss caused by a shield present on a radio wave propagation path between a transmitter that emits radio waves and a receiver that receives radio waves. comprising a memory and a processor.

The memory stores information on the transmitting point, which is the position where the transmitter emits radio waves, information on the receiving point, which is the position where the receiver receives radio waves, and information on the position and shape of the shield. Based on the information stored in the memory, the processor generates a plurality of straight lines extending radially from the transmitting point and passing through points on the outline of the shield viewed from the transmitting point and the shielding extending radially from the receiving point and viewed from the receiving point. Equivalent screen calculation processing for calculating the positions of intersections with a plurality of straight lines that pass through points on the outline of an object, and calculating an equivalent screen area that is a plane area with a set of intersections as the outline; and a radio wave shielding loss calculation process for calculating the radio wave shielding loss assuming that it is shielded.

As described above, according to the present invention, the radio wave shielding loss is calculated by giving an equivalent screen area in consideration of the thickness of the shield, so that the radio wave shielding loss is high even when the thickness of the shield is large. It can be calculated with precision.

FIG. 2 is a conceptual diagram showing an example of a situation targeted by the radio wave shielding loss calculation method according to the present embodiment; FIG. 10 is a diagram for explaining an outline of a calculation method of an equivalent screen area in the radio wave shielding loss calculation method according to the present embodiment; FIG. 10 is a conceptual diagram for explaining a method of calculating the positions of intersections that are contour lines of the equivalent screen area in calculating the equivalent screen area; 4 is a flowchart showing a procedure for calculating radio wave shielding loss; FIG. 4 is a conceptual diagram for explaining mesh division of an equivalent screen area; FIG. 4 is a conceptual diagram for explaining respective values when calculating radio wave shielding loss based on the PO method; It is a block diagram which shows the structural example of a radio wave shielding loss calculation apparatus. 8 is a block diagram showing processing of a radio wave shielding loss calculation program executed by a processor of the radio wave shielding loss calculation apparatus shown in FIG. 7; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, when referring to the number, quantity, amount, range, etc. of each element in the embodiments shown below, unless otherwise specified or the number is clearly specified in principle, the reference The number is not intended to limit the invention. Also, the structures and the like described in the embodiments shown below are not necessarily essential to the present invention, unless otherwise specified or clearly specified in principle. In each figure, the same or corresponding parts are denoted by the same reference numerals, and redundant description thereof will be appropriately simplified or omitted.

1. 1. Target FIG. 1 is a conceptual diagram showing an example of a situation targeted by the radio wave shielding loss calculation method according to the present embodiment. A transmitter 1 and a receiver 2 are installed on the ground GND with a distance therebetween. The transmitter 1 and receiver 2 may be installed directly on the ground GND, or may be installed on a structure on the ground GND. Transmitter 1 and receiver 2 are typically antennas. In this case, the antenna may be an omnidirectional antenna (half-wave dipole antenna, whip antenna, etc.) or a directional antenna (parabolic antenna, Yagi antenna, etc.).

A transmitter 1 emits radio waves 4 . The transmission point Tx is a position where the radio waves 4 are emitted from the transmitter 1 . A receiver 2 receives radio waves 4 . The reception point Rx is a position where the radio waves 4 are received by the receiver 2 . The radio waves 4 emitted by the transmitter 1 are typically carrier waves modulated to contain some information. A transmitter 1 and a receiver 2 communicate by radio waves 4 .

A shield 3 exists on the radio wave propagation path between the transmitter 1 and the receiver 2 . The shielding object 3 is, for example, a person, a tree, a building, or the like. As shown by dotted arrows in FIG. 1 (indicating part of the propagation path of the radio waves 4), the radio waves 4 emitted by the transmitter 1 are affected by absorption, reflection, and scattering by the shield 3. FIG. As a result, part of the radio wave 4 is blocked, and the radio wave intensity of the radio wave 4 received by the receiver 2 is lower than when the radio wave propagates through a space where the shield 3 does not exist. That is, the shield 3 increases propagation loss.

In the radio wave shielding loss calculation method according to the present embodiment, the propagation loss (radio wave shielding loss) due to the shielding object 3 is calculated for the situation shown in FIG.

2. Method for Calculating Radio Wave Shielding Loss In the method for calculating radio wave shielding loss according to the present embodiment, the equivalent screen area, which is a planar area, is determined from information on the position of the transmission point Tx, the position of the reception point Rx, and the position and shape of the shield 3. calculated (equivalent screen calculation step). Then, assuming that the radio wave 4 is shielded by the equivalent screen area ESC instead of the shield 3, the radio wave shielding loss is calculated based on the PO method (radio wave shielding loss calculation step).

Here, the shape information of the shielding object 3 includes at least spatial position information of the entire surface of the shielding object 3 . The spatial positional information of the entire surface may be continuous positional information over the entire surface, or discrete positional information with sufficient accuracy to calculate the equivalent screen area as described later. can be

2-1. Equivalent Screen Calculation Step FIG. 2 is a conceptual diagram for explaining an outline of a method for calculating the equivalent screen area ESC. LS1 in FIG. 2 is a straight line extending radially from the transmission point Tx and passing through a point OP1 on the outline of the shield 3 viewed from the transmission point Tx. LS2 in FIG. 2 is a straight line extending radially from the receiving point Rx and passing through a point OP2 on the outline of the shielding object 3 viewed from the receiving point Rx. Straight lines LS1 and LS2 are connected to continuous or discrete points OP1 and OP2 over the outline of the shield 3 seen from the transmission point Tx and the outline of the shield 3 seen from the reception point Rx. obtained for In FIG. 2, the straight lines LS1 and LS2 are only partially drawn.

In the radio wave shielding loss calculation method, the position of the intersection point IP between the straight lines LS1 and LS2 is calculated. Then, as shown in FIG. 2, the equivalent screen area ESC is calculated as an area whose outline is a set of intersection points IP obtained with respect to the plurality of straight lines LS1 and LS2. If the intersection points IP are discrete here, the equivalent screen area ESC is calculated by connecting two adjacent intersection points IP with an appropriate straight line or curve. Here, calculation of the position of the intersection point IP is performed as follows.

FIG. 3 is a conceptual diagram for explaining a method of calculating the position of the intersection point IP. FIG. 3 shows a view looking into a cross section (dotted line) of the shield 3 by a plane passing through the transmission point Tx, the reception point Rx, and the intersection point IP. A in FIG. 3 is the distance from the transmission point Tx to the shield 3 . b in FIG. 3 is the distance from the receiving point Rx to the shielding object 3 . c in FIG. 3 is the thickness of the shield 3 . In FIG. 3, h is the height from a straight line passing through the transmission point Tx and the reception point Rx to the points OP1 and OP2. Here, it is assumed that the shield 3 does not change in height h in the thickness direction. Distance a, distance b, thickness c, and height h are values given by the shape information of the shield 3 .

The position of the intersection point IP is the horizontal distance x of the intersection point IP with the surface of the shield 3 on the transmission point Tx side as the base point, and the vertical distance of the intersection IP with the straight line passing through the transmission point Tx and the reception point Rx as the base point. given by the height y.

For each value shown in FIG. 3, the following relational expression (1) is obtained from the relationship between the side length ratios.

From the equation (1), the distance x and the height h as the position of the intersection point IP are calculated by the following equations (2) and (3).

2-2. Radio Wave Shielding Loss Calculation Step In the radio wave shielding loss calculation method according to the present embodiment, when it is assumed that the shielding object 3 does not exist, scattered waves emitted from the equivalent screen area ESC based on the PO method are induced at the receiving point Rx. The radio wave shielding loss is calculated assuming that the electric field applied is the electric field shielded by the equivalent screen area ESC.

Further, in the radio wave shielding loss calculation method according to the present embodiment, the equivalent screen area is divided into meshes, and the electric field of scattered waves (hereinafter also referred to as "scattered electric field") is calculated for each mesh. Then, by summing up the scattered electric field of each mesh for the entire mesh, the radio wave shielding loss is calculated by giving the scattered electric field at the receiving point Rx (the electric field induced by the scattered wave at the receiving point Rx).

FIG. 4 is a flow chart showing the procedure for calculating the radio wave shielding loss in the radio wave shielding loss calculation step.

In step S200, mesh division is performed to divide the equivalent screen area ESC into meshes.

Here, FIG. 5 shows a conceptual diagram for explaining the mesh division of the equivalent screen area ESC. The mesh that divides the equivalent screen area ESC is, for example, an isosceles right triangle, as shown in FIG. Alternatively, it may be a suitable figure capable of covering the entire equivalent screen area ESC. The mesh size is about 0.1 times the wavelength λ of the radio waves 4 .

Each mesh is given information on its position in space. In FIG. 5, the position of the mesh is given by the distance rm from the transmission point Tx to the mesh.

Please refer to FIG. 4 again. After performing step S200, the procedure proceeds to step S210.

In steps S210, S220, and S230, the scattered electric field at the reception point Rx is calculated based on the PO method. Here, FIG. 6 shows a conceptual diagram for explaining each value when calculating the scattered electric field at the receiving point Rx based on the PO method. FIG. 6 shows a case where the radio wave shielding loss is calculated for the mesh at the position rm.

The position rm of the mesh and the position r of the reception point Rx are given by a position vector with the transmission point Tx as the reference point, as shown in FIG. At this time, a vector starting from the mesh and ending at the receiving point Rx is r-rm. Also, n in FIG. 6 is a unit normal vector on the equivalent screen area ESC.

4mst in FIG. 6 is a scattered wave radiated from the mesh accompanying the equivalent surface current and equivalent surface magnetic current induced on the mesh at the position rm by the radio wave 4 . Ei, Hi, and ki in FIG. 6 are the electric field, magnetic field, and wave vector of radio waves incident on the mesh at position rm by the radio waves 4, respectively. Ems and ks in FIG. 6 are the scattered electric field and wave vector of the scattered wave 4 mst, respectively.

Please refer to FIG. 4 again. In step S210, the equivalent surface current J and the equivalent surface magnetic current M induced on the mesh at the position rm are calculated. Equivalent surface current J and equivalent surface magnetic current M are given by the following equations (4) and (5), respectively.

Here, Ev and Eh are the component of the electric field Ei in the direction perpendicular to the plane of incidence and the component in the horizontal direction. Hv and Hh are the incident surface vertical component and horizontal component of the magnetic field Hi. Rv and Rh are the vertical and horizontal polarization reflection coefficients and scalars of the equivalent screen area ESC at the mesh position rm.

Since the equivalent screen area ESC is an area having no physical quantity calculated in the equivalent screen calculation step, the reflection coefficients Rv and Rh are zero. Therefore, from the equations (4) and (5), the equivalent surface current J and the equivalent surface magnetic current M are given by the following equations (6) and (7).

The equivalent surface current J and the equivalent surface magnetic current M are calculated by these equations (6) and (7). Here, the electric field Ei and the magnetic field Hi are calculated from the information of the radio wave 4, the information of the propagating space, and the position rm of the mesh. The unit normal vector n is given by the equivalent screen area ESC.

After performing step S210, the procedure proceeds to step S220.

In step S220, the electric vector potential A and the magnetic vector potential B for the equivalent surface current J and the equivalent surface magnetic current M are calculated.

The electric vector potential A and the magnetic vector potential B are obtained by the following equations (8) and ( 9). The electric vector potential A and the magnetic vector potential B are functions of the position r.

where e is Napier's number and j is the imaginary unit. Sm represents the area of the mesh, and indicates that the integration in the equations (8) and (9) is an area integral with the area of the mesh as the integration range.

After performing step S220, the procedure proceeds to step S230.

In step S230, the scattered electric field Ems in the mesh at the position rm is calculated. Then, the scattered electric field Es at the reception point Rx is calculated by summing the scattered electric fields Ems for each mesh over the entire mesh.

Generally, the distance |r−rm| between the mesh and the receiving point Rx is sufficiently larger than the wavelength λ of the radio wave 4 . The size of the mesh is about 0.1 times the wavelength λ as described above. Therefore, the scattered electric field Ems is calculated by the following equation (10) as the far field. The scattered electric field Ems is a function of position r.

Here, ε is the vacuum permittivity, μ is the vacuum permeability, η is the wave impedance, and ω is the angular frequency of the radio wave 4 . ksn is a unit vector with the direction of the wave vector ks.

The scattered electric field Es at the receiving point Rx is calculated by the following equation (11). The scattered electric field Es is a function of position r.

where aTH and aTE are the gains provided by the azimuth and elevation radiation patterns of transmitter 1, respectively. aRH and aRE are the gains provided by the azimuth and elevation radiation patterns of receiver 2, respectively. These radiation patterns are provided as information for transmitter 1 and receiver 2 . C represents the set over the mesh, indicating that the sum in equation (11) is computed over the mesh.

After performing step S230, the procedure proceeds to step S240.

In step S240, assuming that the scattered electric field Es at the position r of the receiving point Rx is the electric field shielded by the equivalent screen area ESC, the following equation (12) is calculated as the radio wave shielding loss.

Furthermore, the power level of radio waves received at the receiving point Rx may be calculated by the following equation (13).

Here, Efree is the electric field of the radio wave 4 received by the receiving point Rx in a space where the shield 3 does not exist. The electric field Efree is calculated from the information of the transmitter 1, the information of the receiver 2, the information of the radio wave 4, and the information of the propagating space.

3. Radio Wave Shielding Loss Calculation Apparatus The radio wave shielding loss calculation method according to the present embodiment is executed by the radio wave shielding loss calculation apparatus described below.

3-1. Configuration Example FIG. 7 is a block diagram showing a configuration example of the radio wave shielding loss calculation device 10 according to the present embodiment. The radio wave shielding loss calculator 10 is typically a computer that performs various types of information processing. The radio shielding loss calculator 10 includes a memory 11 and a processor 12 . The radio wave shielding loss calculation apparatus 10 receives as input propagation environment information indicating the environment in which radio waves propagate, and outputs the radio wave shielding loss.

The propagation environment information includes information on the transmitter 1, information on the receiver 2, information on the shield 3, and information on the propagation space. The information of the transmitter 1 includes at least the position of the transmission point Tx, the radiation patterns of the transmitter 1 in the azimuth and elevation directions, and the information of the radio waves 4 emitted by the transmitter 1 (electric field, magnetic field, and wave vector). contains. The information of the receiver 2 includes at least the position of the reception point Rx and the radiation patterns of the receiver 2 in the azimuth and elevation directions. Information of the space to be propagated includes at least permittivity and magnetic permeability.

The radio wave shielding loss calculation device 10 may be applied as part of a radio wave propagation simulation device (for example, a simulation device using ray tracing) for the purpose of preliminary investigation for constructing a communication system, or may be applied to the communication system. It may be applied as an evaluation device that evaluates the influence of the shield 3 that exists during operation.

The propagation environment information is given in advance as simulation conditions when the radio wave shielding loss calculation device 10 is applied as a simulation device. On the other hand, when the radio wave shielding loss calculation device 10 is applied as an evaluation device during operation of a communication system, information on the transmitter 1, the receiver 2, and the propagating space is given in advance as known information, Information about the shielding object 3 is given by a value detected by a sensor device such as a camera or radar.

The memory 11 includes a RAM (Random Access Memory) for temporarily storing data and a ROM (Read Only Memory) for storing control programs executable by the processor 12 and various data related to the control programs. . Propagation environment information given to the radio shielding loss calculator 10 is stored in the memory 11 .

The processor 12 executes the radio wave shielding loss calculation program PGM to calculate the radio wave shielding loss based on the radio wave environment information read from the memory 11 . Here, the radio shielding loss calculation program PGM is stored in the memory 11 as shown in FIG. 7, and the processor 12 reads the radio shielding loss calculation program PGM from the memory 11 and executes it. Alternatively, the radio wave shielding loss calculation device 10 is connected to a network (not shown), and the radio wave shielding loss calculation program PGM is provided to the radio wave shielding loss calculation device 10 via the network. may be executed.

3-2. Radio Wave Shielding Loss Calculation Program FIG. 8 is a block diagram showing processing performed by the processor 12 by executing the radio wave shielding loss calculation program PGM. The processor 12 executes an equivalent screen calculation process PRC1 and a radio wave shielding loss calculation process PRC2 by executing the radio wave shielding loss calculation program PGM.

In the equivalent screen calculation process PRC1, the processor 12 calculates the equivalent screen area from information on the position of the transmission point Tx, the position of the reception point Rx, and the position and shape of the shield 3, as shown in the equivalent screen calculation step described above. Calculate ESC. Information on the position of the transmission point Tx, the position of the reception point Rx, and the position and shape of the shield 3 are given by the propagation environment information.

In the radio wave shielding loss calculation process PRC2, the processor 12 calculates the radio wave shielding loss based on the propagation environment information and the equivalent screen area ESC, as shown in the radio wave shielding loss calculation step described above.

The processing executed by the processor 12 in the radio wave shielding loss calculation processing PRC2 is the same as the flowchart shown in FIG. Therefore, description here is omitted.

4. Effect As described above, in the radio wave shielding loss calculation method and the radio wave shielding loss calculation apparatus according to the present embodiment, the equivalent screen area considering the thickness of the shield 3 in the equivalent screen calculation step (equivalent screen calculation process PRC1) ESC is calculated. Then, in the radio wave shielding loss calculation step (radio wave shielding loss calculation process PRC2), the radio wave shielding loss is calculated based on the PO method, assuming that the radio waves 4 are shielded by the equivalent screen area ESC instead of the shielding object 3 . As a result, the radio wave shielding loss can be calculated in consideration of the thickness of the shield 3, and the radio wave shielding loss can be calculated with high accuracy even when the thickness of the shield 3 is large.

1 Transmitter 2 Receiver 3 Shield 10 Radio wave shielding loss calculation device 11 Memory 12 Processor PGM Radio wave shielding loss calculation program PRC1 Equivalent screen calculation process PRC2 Radio wave shielding loss calculation process ESC Equivalent screen area Tx Transmission point Rx Reception point OP1 From transmission point Point OP2 on the outline of the shielding object seen Point LS1 on the outline of the shielding object seen from the receiving point Straight line LS2 passing through the transmitting point and point OP1 Straight line IP passing through the receiving point and point OP2 Intersection point of straight lines LS1 and LS2

Claims (6)

A radio wave shielding loss calculation method for calculating the radio wave shielding loss of the radio wave caused by a shield present on a radio wave propagation path between a transmitter that emits radio waves and a receiver that receives the radio waves,
A transmission point is a position where the transmitter emits the radio waves,
The reception point is a position where the receiver receives the radio waves,
A plurality of straight lines extending radially from the transmitting point and passing through points on the outline of the shield viewed from the transmitting point, and points on the outline of the shield extending radially from the receiving point and viewed from the receiving point. an equivalent screen calculation step of calculating positions of intersections with a plurality of straight lines passing through and calculating an equivalent screen region, which is a plane region having a set of intersections as an outline;
a radio wave shielding loss calculation step of calculating the radio wave shielding loss assuming that the radio waves are shielded by the equivalent screen area;
A radio wave shielding loss calculation method, comprising: 2. The method of claim 1, wherein
The radio wave shielding loss calculation step includes:
The radio wave shielding loss is calculated by assuming that the electric field induced at the receiving point by the scattered waves emitted from the equivalent screen area when the shield does not exist is the electric field shielded by the equivalent screen area. A radio wave shielding loss calculation method characterized by: 3. A method according to claim 1 or 2,
The radio wave shielding loss calculation step includes:
dividing the equivalent screen area by a mesh;
A radio wave shielding loss calculation method, comprising: calculating the radio wave shielding loss for each of the meshes; and calculating the radio wave shielding loss by adding the radio wave shielding loss for each mesh to the entire mesh. A radio wave shielding loss calculation device for calculating the radio wave shielding loss of the radio wave due to a shield present on the radio wave propagation path between a transmitter that emits the radio wave and a receiver that receives the radio wave,
memory;
a processor;
with
The memory is
Information on a transmission point, which is a position from which the transmitter emits the radio wave;
Information on a receiving point, which is the position of the receiver from which the radio waves are emitted;
storing information on the position and shape of the shield, and
The processor
Based on the information stored in the memory, a plurality of straight lines extending radially from the transmission point and passing through points on the outline of the shield seen from the transmission point, and a plurality of straight lines extending radially from the reception point and extending from the reception point Equivalent screen calculation processing for calculating the positions of intersections with a plurality of straight lines passing through points on the contour line of the viewed shield, and calculating an equivalent screen region, which is a plane region having the set of intersections as the contour line;
radio wave shielding loss calculation processing for calculating the radio wave shielding loss assuming that the radio wave is shielded in the equivalent screen area;
A radio wave shielding loss calculation device characterized by executing The radio wave shielding loss calculation device according to claim 4,
In the radio wave shielding loss calculation process, the processor
Calculating the radio wave shielding loss assuming that the electric field induced at the receiving point by the scattered waves emitted from the equivalent screen area when the shield does not exist is the electric field shielded by the equivalent screen area. A radio shielding loss calculator characterized by: A radio wave shielding loss calculation program that is executed by a computer and causes the computer to execute the radio wave shielding loss calculation method according to any one of claims 1 to 3.

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