Method for measuring reception power, method for calculating power reflection efficiency, program for measuring reception power, and program for calculating power reflection efficiency

Abstract

The present application provides a method for measuring received power capable of properly measuring received power of an electromagnetic wave reflection device having a super surface or a regular reflection surface. The method for measuring received power in an anechoic chamber provided with a VNA connected to a transmission and reception antenna with a fixed relative position, transmits an electromagnetic wave of a prescribed frequency band selected from a waveband of 1 MHz or more and 300 GHz or less from the transmission antenna so as to be incident on the electromagnetic wave reflection device at a first specified incident angle, receives a reflected wave using a reception antenna disposed in a direction of a first specified reflection angle with respect to the electromagnetic wave reflection device, and measures a first received power in a specified frequency range using the VNA. In the anechoic chamber, an electromagnetic wave of the prescribed frequency band is transmitted from the transmission antenna so as to be incident on a reflection plate having a metal reflection surface at a second specified incident angle, a reflected wave is received using a reception antenna disposed in a direction of a second specified reflection angle with respect to the reflection plate having a metal reflection surface, and a second received power in a specified frequency range is measured using the VNA.

Description

Technical Field

[0001] This disclosure relates to a method for measuring received power, a method for calculating power reflection efficiency, a procedure for measuring received power, and a procedure for calculating power reflection efficiency. Background Technology

[0002] In the fifth-generation (hereinafter referred to as "5G") mobile communication standard, high-speed and high-capacity communication is expected. On the other hand, due to the use of highly linear radio waves, there are locations where the radio waves are difficult to reach. In places with a large amount of metal machinery, such as factories, or in areas with significant reflections from walls and trees, such as building blocks, methods are needed to deliver radio waves to target terminal devices and wireless equipment. The same need exists in locations such as medical facilities, event venues, and large commercial facilities where there are points where the base station antenna cannot be directly seen (NLOS). The next generation, the sixth generation, is also expected to use the terahertz band or the Asia-Pacific Hertz band, and similar needs will arise.

[0003] In recent years, reflective surfaces with artificial surfaces known as "metasurfaces" have been developed. Metasurfaces are formed from periodic structures or patterns finer than the wavelength and are designed to reflect electromagnetic waves in a desired direction (e.g., see Non-Patent Document 1). Because metasurfaces can achieve the desired reflection angle while maintaining a planar configuration, they function effectively as reflectors even in environments where there is no space to accommodate multiple reflective panels. Structures for wireless transmission systems incorporating electromagnetic wave reflecting devices with metasurfaces or regular reflective surfaces have been proposed for use on production lines in factories and workshops (e.g., see Patent Documents 1 and 2).

[0004] Patent Document 1: International Publication No. 2021 / 199503

[0005] Patent Document 2: International Publication No. 2021 / 199504

[0006] Non-patent literature 1: Diaz-Rubio et al., Sci. Adv. 2017: 3: e1602714 1

[0007] However, when implementing conventional wireless transmission systems, the power reflection efficiency needs to be appropriately evaluated when designing electromagnetic wave reflecting devices and base station configurations based on the power reflection efficiency of electromagnetic wave reflecting devices with metasurfaces or regular reflective surfaces. Furthermore, even when configuring electromagnetic wave reflecting devices with metasurfaces or regular reflective surfaces, not limited to conventional wireless transmission systems, the power reflection efficiency also needs to be appropriately evaluated.

[0008] However, a suitable method for evaluating the power reflection efficiency of electromagnetic wave reflecting devices with metasurfaces or regular reflective surfaces has not yet been established. Furthermore, to evaluate power reflection efficiency, it is necessary to appropriately evaluate the received power within the electromagnetic wave reflecting device. Summary of the Invention

[0009] Therefore, the purpose of this disclosure is to provide a method for measuring the received power in an electromagnetic wave reflecting device having a metasurface or a regular reflective surface, and a method for calculating the power reflection efficiency in an electromagnetic wave reflecting device having a metasurface or a regular reflective surface.

[0010] The method for measuring the received power according to the embodiments of this disclosure includes: a first step, in an anechoic chamber equipped with a vector network analyzer connected to a transmitting antenna and a receiving antenna fixed in relative positions, transmitting radio waves from the transmitting antenna in a predetermined frequency band selected from a band of 1 MHz or higher and 300 GHz or lower, and subjecting them to an electromagnetic wave reflecting device at a first specified incident angle; a second step, using the receiving antenna positioned in a direction corresponding to the first specified reflection angle relative to the electromagnetic wave reflecting device, receiving the reflected power of the radio waves incident on the electromagnetic wave reflecting device in the first step. The process involves: 1) transmitting a radio wave in the specified frequency band from the transmitting antenna inside the anechoic chamber, causing it to be incident on a reflector having a metal reflective surface at a second specified incident angle; 2) using the receiving antenna positioned at the second specified reflection angle relative to the reflector having the metal reflective surface, receiving the reflected wave of the radio wave incident on the metal reflector in the third step, and using the vector network analyzer to determine the second received power within the specified frequency range.

[0011] This disclosure provides a method for measuring received power in an electromagnetic wave reflecting device having a metasurface or a regular reflective surface, and a method for calculating power reflection efficiency in an electromagnetic wave reflecting device having a metasurface or a regular reflective surface. Attached Figure Description

[0012] Figure 1 This is a diagram illustrating an example of the structure of an electromagnetic wave reflecting device 60 using the reflective panel 10 of the embodiment.

[0013] Figure 2 This is a diagram illustrating an example of the structure of an electromagnetic wave reflecting fence 100 formed by connecting electromagnetic wave reflecting devices 60-1, 60-2, and 60-3.

[0014] Figure 3 This is a diagram showing an example of the layer structure of the reflective panel 10.

[0015] Figure 4 This is a diagram showing an example of the layer structure of the reflective panel 10A.

[0016] Figure 5 This is a diagram illustrating an example of the structure of a unit cell 20 of a conductive pattern 15 composed of a hollow pattern 151.

[0017] Figure 6 This is a diagram showing an example of a measuring device configured in an anechoic chamber 101.

[0018] Figure 7A This is a diagram illustrating an example of a method for calculating the power reflection efficiency of an implementation.

[0019] Figure 7B This is a diagram illustrating an example of a method for calculating the power reflection efficiency of an implementation.

[0020] Figure 8 This is a flowchart illustrating an example of the processing of a method for measuring received power and a method for calculating power reflection efficiency according to an embodiment.

[0021] Figure 9A This is a figure showing an example of the measurement results for the electromagnetic wave reflecting device 60A, when the correction value is less than 1 and the measurement distance does not change significantly even with slight deviations, of the distance from the transmitting antenna 115Tx to the electromagnetic wave reflecting device 60A on the path of the incident wave and the distance from the electromagnetic wave reflecting device 60A to the receiving antenna 115Rx on the path of the reflected wave.

[0022] Figure 9B This is a figure showing an example of the measurement results for the electromagnetic wave reflecting device 60A, when the correction value is less than 1 and the measurement distance does not change significantly even with slight deviations, of the distance from the transmitting antenna 115Tx to the electromagnetic wave reflecting device 60A on the path of the incident wave and the distance from the electromagnetic wave reflecting device 60A to the receiving antenna 115Rx on the path of the reflected wave.

[0023] Figure 9C This is a diagram showing an example of the structure of the reflecting surface of the electromagnetic wave reflecting device 60A.

[0024] Figure 10 This means fitting a quadratic curve to... Figure 9A A diagram illustrating an example of the results obtained. Detailed Implementation

[0025] The following describes embodiments of the method for measuring received power, the method for calculating power reflection efficiency, the procedure for measuring received power, and the procedure for calculating power reflection efficiency using the present disclosure. Hereinafter, the same reference numerals will be used to label the same elements, and repeated descriptions will sometimes be omitted.

[0026] Before describing the method for measuring received power, the method for calculating power reflection efficiency, the procedure for measuring received power, and the procedure for calculating power reflection efficiency, the structure of an electromagnetic wave reflecting device with a metasurface or regular reflective surface included in a wireless transmission system that can be used outdoors or indoors will be described below. In addition to such an electromagnetic wave reflecting device, the wireless transmission system also includes a base station, which establishes a wireless communication area in an outdoor or indoor facility.

[0027] The XYZ coordinate system will be defined below for explanation. The direction parallel to the X-axis (X direction), the direction parallel to the Y-axis (Y direction), and the direction parallel to the Z-axis (Z direction) are orthogonal to each other. For ease of explanation, the -Z direction side will sometimes be referred to as the lower side or down, and the +Z direction side as the upper side or up. Top view refers to viewing from the XY plane. Furthermore, to facilitate understanding of the structure, the length, thickness, etc., of each part will sometimes be exaggerated. Also, variations in the use of terms such as parallel, right angle, orthogonal, horizontal, vertical, and up / down are permitted without compromising the effectiveness of the implementation.

[0028] In the implementation, electromagnetic wave reflection devices are used in wireless transmission systems used indoors and outdoors to reduce blind spots. In this specification, a "blind spot" refers to an area where the received power is reduced by more than 10 dB compared to the surrounding unobstructed receiving environment due to the influence of obstructions. Generally, electromagnetic waves below 3 THz are called radio waves, but in this specification, communication waves transmitted from the base station are referred to as "radio waves," and electromagnetic waves are generally referred to as "electromagnetic waves."

[0029] Blind spots encompass not only two-dimensional areas but also three-dimensional space. If production equipment, sensors, or mobile communication terminals with wireless communication capabilities are located in blind spots, it becomes difficult for them to transmit and receive signals with base stations. Therefore, electromagnetic wave reflection devices are introduced to reduce blind spots and improve the electromagnetic environment.

[0030] <Implementation Method>

[0031] Figure 1 This is a diagram illustrating an example of the structure of an electromagnetic wave reflecting device 60 using the reflective panel 10 of the embodiment. The electromagnetic wave reflecting device 60 has a reflective panel 10 and a frame 50 that holds the reflective panel 10. Figure 1In the coordinate system, with the electromagnetic wave reflecting device 60 installed, the width or lateral direction of the reflecting panel 10 is set as the X direction, the height or longitudinal direction as the Y direction, and the thickness direction as the Z direction. The reflecting panel 10 reflects electromagnetic waves from the gigahertz band to the terahertz band, such as microwaves, millimeter waves, and submillimeter waves, for example, electromagnetic waves above 1 MHz and below 300 GHz.

[0032] As an example, in a wireless transmission system including an electromagnetic wave reflection device 60, the radio waves transmitted and received by the base station are preferably radio waves in the 1MHz to 300GHz band, including the Sub-6 GHz band and the millimeter wave band, as used in fifth-generation mobile communication systems (5G). Currently, the 28GHz frequency band included in the Sub-6 GHz band and the millimeter wave band is utilized, and it is expected that the next-generation 6G mobile communication standard will extend to the Asia-Pacific Hertz band. By using such a high-frequency band, the communication bandwidth can be significantly expanded, enabling large-volume data communication with low latency.

[0033] In addition, the radio waves transmitted and received by the base station can also be LTE (Long Term Evolution), LTE-A (LTE-Advanced), UMB (Ultra Mobile Broadband), or CBRS (Citizens Broadband Radio Service). Furthermore, the radio waves transmitted and received by the base station can also be IEEE 802.11 (Wi-Fi, a registered trademark), IEEE 802.16 (WiMAX, a registered trademark), IEEE 802.20, UWB (Ultra-Wideband), Bluetooth, or LPWA (Low Power Wide Area), etc.

[0034] The reflective panel 10 can have a specular reflective surface where the incident angle and the exit angle of the electromagnetic wave are equal, or it can have a metasurface where the reflection direction is controlled. The reflective panel 10 can also be a structure combining a specular reflective surface and a metasurface. The metasurface can also be designed to not only provide a non-spectral reflective surface that reflects the incident electromagnetic wave in a direction different from the incident angle, but also control the diffusion state of the electromagnetic wave.

[0035] The metasurface of the reflective panel 10 reflects both horizontally polarized waves and vertically polarized waves in a controlled direction. Horizontally polarized waves are polarized waves that vibrate laterally relative to a direction parallel to the ground or the direction of propagation. Vertically polarized waves are polarized waves that vibrate longitudinally relative to a direction perpendicular to the ground or the direction of propagation. By forming a conductive pattern of hollow quadrilaterals that constitutes the metasurface, both horizontally and vertically polarized waves can be reflected in a controlled direction.

[0036] The frame 50 holds both sides of the reflector panel 10 along the height direction when it is installed. In addition to the frame 50, a top frame 57 holding the upper end of the reflector panel 10 and a bottom frame 58 holding the lower end may also be provided. In this case, the frame 50, top frame 57, and bottom frame 58 constitute a frame that holds the entire circumference of the reflector panel 10. The frame 50, depending on its positional relationship relative to the top frame 57 and bottom frame 58, may also be referred to as a "side frame". Legs 56 supporting the frame 50 may also be provided. Figure 1 Therefore, when the electromagnetic wave reflecting device 60 is placed on the mounting surface, it is preferable to provide legs 56, but legs 56 are not necessary. Casters can be provided on the legs 56 to make it movable, or the reflecting panel 10 can be mounted on the wall or suspended from the ceiling without legs 56.

[0037] Figure 2 This diagram illustrates an example of the structure of an electromagnetic wave reflecting fence 100 formed by connecting electromagnetic wave reflecting devices 60-1, 60-2, and 60-3. Figure 2 In this process, three electromagnetic wave reflecting devices 60-1, 60-2 and 60-3 (hereinafter, sometimes appropriately referred to collectively as "electromagnetic wave reflecting devices 60") are connected to form an electromagnetic wave reflecting fence 100, but there is no particular limitation on the number of electromagnetic wave reflecting devices 60 connected.

[0038] Electromagnetic wave reflecting devices 60-1, 60-2, and 60-3 each have reflecting panels 10-1, 10-2, and 10-3, respectively. By holding adjacent reflecting panels together with a frame 50, an electromagnetic wave reflecting fence 100 connected in the X direction can be obtained. Reflecting panels 10-1, 10-2, and 10-3 (hereinafter, sometimes appropriately referred to collectively as "reflecting panels 10") each have a reflective surface formed by a hollow quadrilateral conductive pattern in at least a portion. Thus, both horizontally polarized and vertically polarized electromagnetic waves are reflected in a controlled direction.

[0039] <Layer Structure of Reflective Panel 10>

[0040] Figure 3 This is a diagram showing an example of the layer structure of the reflective panel 10. Figure 3 The layered structure shown is the layered structure in the XZ section of the reflective panel 10, with the stacking direction being the thickness direction (Z direction) of the reflective panel 10. As an example, in... Figure 3 A cross-section of the reflective panel 10 as viewed from the (-Y direction side) is shown.

[0041] The reflective panel 10 has a dielectric layer 11, a periodic conductive pattern 15 disposed on one surface 11A of the dielectric layer 11, and a ground layer 12 disposed on the other surface 11B of the dielectric layer 11. The conductive pattern 15 forms the reflective surface of the reflective panel 10, reflecting electromagnetic waves of 1 MHz or higher and 300 GHz or lower in a predetermined direction.

[0042] The conductive pattern 15 comprises a periodic arrangement of a plurality of hollow patterns 151. The specific shape of the hollow patterns 151 will be described later. Figure 5 The following explanation is provided. As an example, the hollow pattern is formed from good conductors such as Ag, Cu, Ni, and Al, and as an example, its thickness is 0.01 mm or more and 0.05 mm or less. If it is less than 0.01 mm, the surface resistivity becomes high, making it difficult to maintain high reflection efficiency. If it is thicker than 0.05 mm, it is difficult to maintain the flatness of the reflective surface. Alternatively, a transparent thin film with the same dielectric constant and dielectric loss tangent as the dielectric layer 11 can be used to protect the surface of the conductive pattern 15.

[0043] As an example, the hollow pattern 151 is bonded to the dielectric layer 11 by an adhesive layer 13. As an example, the adhesive layer 13 is not coated across the entire surface of the dielectric layer 11, but only in an amount necessary to stably hold the hollow pattern 151. This is to minimize the effect of the adhesive layer 13 on the dielectric constant of the dielectric layer 11. The area occupied by the adhesive layer 13 does not need to be exactly the same as the area occupied by the conductive pattern 15, and can deviate slightly within a range that allows the hollow pattern 151 to be stably bonded to the dielectric layer 11. For example, if the area occupancy of the conductive pattern 15 relative to the dielectric layer 11 is 10.0% or more and 45.0% or less, then the area occupancy of the adhesive layer 13 relative to the dielectric layer 11 is 9.0% or more and 50.0% or less.

[0044] If the area occupancy of the conductive pattern 15 is less than 10.0%, it is difficult to achieve the desired reflective characteristics and reflective efficiency. If the area occupancy of the conductive pattern 15 exceeds 45.0%, it is difficult to maintain the transparency of the reflective panel 10. However, in applications where transparency is not required, the area occupancy of the conductive pattern 15 can be greater than 45.0% to prioritize reflective efficiency.

[0045] The adhesive layer 13 is made of a material capable of bonding the conductive pattern 15 to the dielectric layer 11. For example, thermoplastic resins such as vinyl acetate resin, acrylic resin, cellulose resin, and silicone resin can also be used. The thickness of the adhesive layer 13 is such that the conductive pattern 15 can be stably bonded to the dielectric layer 11, for example, it is 0.002 mm or more and 0.050 mm or less. From the viewpoint of ensuring adhesion, it is preferable to be 0.010 mm or more and 0.050 mm or less.

[0046] The dielectric layer 11 is an insulating polymer film such as polycarbonate, cyclic olefin polymer (COP), polyethylene terephthalate (PET), or fluororesin, with a thickness of approximately 0.3 mm to 1.0 mm. The dielectric layer 11 only needs to be made of a material with a relative permittivity and dielectric loss tangent suitable for achieving the target reflection characteristics.

[0047] The ground layer 12 can be formed of the same material as the conductive pattern 15, or it can be formed of a different conductive material. A predetermined parasitic capacitance is formed between the ground layer 12 and the conductive pattern 15. The amount of phase delay is determined by the parasitic capacitance formed between the conductive pattern 15 and the ground layer 12.

[0048] Figure 4 This is a diagram illustrating an example of the layer structure of the reflective panel 10A. This layer structure has... Figure 3 The structure consists of two dielectric substrates 21 and 22 sandwiched between them. Dielectric substrate 21 is bonded to ground layer 12 via adhesive layer 23. Dielectric substrate 22 is bonded to the conductive pattern 15 side of dielectric layer 11 via adhesive layer 24. Dielectric substrates 21 and 22 are transparent to electromagnetic waves from the gigahertz band to the terahertz band, specifically 1 MHz or higher and 3 THz or lower, for example, 1 MHz or higher and 300 GHz or lower. As the outermost layer of reflective panel 10A, dielectric substrates 21 and 22 are preferably formed of materials with excellent impact resistance, durability, and transparency. Polycarbonate, acrylic resin, PET, etc., can be used as dielectric substrates 21 and 22. The thickness of dielectric substrates 21 and 22 can be appropriately selected from, for example, between 1.0 mm and 10.0 mm, depending on the installation location. The thicknesses of dielectric substrates 21 and 22 can be the same or different.

[0049] Adhesive layer 23 protects the surface of ground layer 12 and adheres to and holds dielectric substrate 21. Adhesive layer 24 protects the surface of conductive pattern 15 and adheres to and holds dielectric substrate 22. Adhesive layers 23 and 24 are preferably durable and moisture-resistant, and can be, for example, ethylene-vinyl acetate (EVA) copolymers or cyclic olefin polymers (COP). The thickness of adhesive layers 23 and 24 can be suitably determined in the range of 10 μm to 400 μm to enable bonding of dielectric substrates 21 and 22.

[0050] By covering the conductive pattern 15 with adhesive layer 24 and bonding it to the dielectric substrate 22, moisture and air intrusion into the surface of the conductive pattern 15 are suppressed, thus suppressing the degradation of the reflective surface. Similarly, by covering the ground layer 12 with adhesive layer 23 and bonding it to the dielectric substrate 21, moisture and air intrusion into the surface of the ground layer 12 are suppressed, thus suppressing the surface degradation of the ground layer 12. Therefore, the capacitance between the ground layer 12 and the conductive pattern 15 can be maintained constant, maintaining the designed phase delay. That is, the reflection efficiency of the radio wave in the designed direction can be maintained.

[0051] <Example of a hollow pattern structure>

[0052] Figure 5 This is a diagram illustrating an example of the structure of a unit cell 20 of a conductive pattern 15 composed of a hollow pattern 151.

[0053] exist Figure 5 In the example shown, unit cell 20 has six hollow patterns 151a, 151b, 151c, 151d, 151e, and 151f. The directions of the width W1 and length L of the hollow patterns 151a to 151f correspond to... Figure 2 The reflective panel 10 of A has width (X) and height (Z) directions. For hollow patterns 151a to 151f, the width W1 is equal, the length L is different, but the central axes of the lengths are aligned (the Y coordinate position of the central axis is constant). The spacing or interval G in the X direction is constant. The phase of the reflection is suppressed by the shape and size of the hollow patterns 151a to 151f, and a reflected beam is formed in the desired direction by the superposition of the reflected waves. In this example, the unit cell 20 is designed to reflect the beam of reflected electromagnetic waves that are incident perpendicularly (incident angle 0°) in a direction at 50° to the vertical.

[0054] Hollow patterns 151a, 151b, 151c, 151d, 151e, and 151f (hereinafter, sometimes collectively referred to as "hollow pattern 151") are hollowed out with a width W2. The hollow patterns have a rectangular ring shape when viewed from the XZ plane. Half the difference between the outer circumference width W1 and the inner circumference width W2 of each hollow pattern 151 is the width of the longitudinal line segment. Similarly, the thickness of the transverse line segment of the hollow pattern 151 is determined by the area of ​​the hollowed-out portion. Both vertically polarized and horizontally polarized radio waves can be reflected through the longitudinal and transverse line segments of the hollow pattern 151.

[0055] The corners of the outer edge of the hollow pattern 151 can be right angles without curvature, or they can be curved with a radius of curvature R1. In the case of right angles, the radius of curvature R1 = 0.0 mm. The corners of the inner periphery of the hollow pattern 151 are curved with a radius of curvature R2. The radius of curvature R1 is the same as or less than R2. By rounding the corners of the hollow pattern 151, especially the corners on the inner edge side, with a specified radius of curvature, current concentration is prevented and reflection efficiency is maintained. Specifically, by giving the corners on the inner edge side of the hollow pattern 151 a radius of curvature R2 of more than 1 / 10 and less than 1 / 2 of the width W1, current concentration can be suppressed, and both vertically polarized waves and horizontally polarized waves can be responded to.

[0056] The conductive pattern 15 is a periodic pattern formed by repeatedly arranging unit cells 20 in the X and Z directions. By providing a reflective surface formed by the conductive pattern 15 on at least a portion of the reflective panel 10, it is possible to reflect the incident horizontally polarized wave and vertically polarized wave electromagnetic waves in a controlled direction.

[0057] <Method for measuring received power and calculating power reflection efficiency according to the embodiments>

[0058] Here, firstly, using Figure 6 An example of a measuring device for measuring the received power of an electromagnetic wave reflection device 60 will be described.

[0059] <Measuring Equipment>

[0060] Figure 6 This diagram illustrates an example of a measurement device configured in an anechoic chamber 101. Here, a VNA (Vector Network Analyzer) 110 is used as the measurement device. A transmitting antenna 115Tx and a receiving antenna 115Rx are connected to the VNA 110 via a cable 110A. Furthermore, the transmitting antenna 115Tx faces the electromagnetic wave reflecting device 60, and the receiving antenna 115Rx is positioned in the reflection direction of the electromagnetic wave reflecting device 60.

[0061] Additionally, a PC (Personal Computer) 120 is connected to VNA 110. PC 120 can also be located inside the anechoic chamber 101, but... Figure 6 As an example, it is configured outside the anechoic chamber 101.

[0062] As an example, the electromagnetic wave reflecting device 60, the transmitting antenna 115Tx, and the receiving antenna 115Rx are positioned at a predetermined height on the floor within the anechoic chamber 101 using components such as a tripod. During measurements, the relative positions of the transmitting antenna 115Tx and the receiving antenna 115Rx are fixed. Furthermore, the position of the electromagnetic wave reflecting device 60 relative to the transmitting antenna 115Tx and the receiving antenna 115Rx is also fixed.

[0063] Furthermore, when changing the angle of the electromagnetic wave reflecting device 60 relative to the transmitting antenna 115Tx and the receiving antenna 115Rx, depending on whether the electromagnetic wave reflecting device 60 is a metasurface that performs non-speculative reflection or a reflective device that performs specular reflection, the transmitting antenna 115Tx and the receiving antenna 115Rx can be fixed while the angle of the electromagnetic wave reflecting device 60 is changed, or the angle of the electromagnetic wave reflecting device 60 can be fixed while the positions (or orientations) of the transmitting antenna 115Tx and the receiving antenna 115Rx are changed. Alternatively, the positions (or orientations) of both the electromagnetic wave reflecting device 60 and the transmitting antenna 115Tx and the receiving antenna 115Rx can also be changed.

[0064] <VNA110>

[0065] In addition to the transmitting circuit section that sends the transmitted signal to the transmitting antenna 115Tx and the receiving circuit section that measures the power (received power) of the received signal received by the receiving antenna 115Rx, the VNA110 also includes a processing unit 111 and a memory 112. Figure 6 The transmitting circuit and receiving circuit of VNA110 are omitted in the text.

[0066] Furthermore, this section describes a VNA 110 with a transmitting antenna 115Tx and a receiving antenna 115Rx connected to it. However, the VNA 110 can also be structured as follows: it is separated into a VNA connected to the transmitting antenna 115Tx and a VNA connected to the receiving antenna 115Rx, and the two VNAs are connected by an optical fiber or the like, so that they can work together.

[0067] The VNA110 incorporates a computer system for implementing the processing unit 111 and the memory 112. The computer system is implemented using components including a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), input / output interfaces, and an internal bus. The processing unit 111 is represented as a functional module that executes programs from the VNA110's computer system. Furthermore, the memory 112 is a functional representation of the memory within the VNA110's computer system.

[0068] <Processing Department 111>

[0069] The processing unit 111 controls the transmitting circuit and receiving circuit of the VNA 110 to process the transmitting antenna 115Tx to radiate radio waves and to measure the received power of the radio waves received by the receiving antenna 115Rx. This processing is achieved by the received power measurement method of the embodiment.

[0070] In the process of causing the transmitting antenna 115Tx to radiate radio waves, the processing unit 111 controls the transmitting circuit unit to transmit radio waves from the transmitting antenna 115Tx in a predetermined frequency band selected from the band of 1MHz to 300GHz. The selection of the predetermined frequency band is performed by the operator of the PC120 inputting the desired frequency band to the PC120, and the PC120 transmitting data representing the predetermined frequency band to the VNA 110. Alternatively, the selection of the predetermined frequency band can also be performed directly on the VNA 110 without going through the PC120.

[0071] In the process of measuring the received power, the processing unit 111 controls the receiving circuit to scan the frequency of the received power within a specified frequency range and measures the received power in the electromagnetic wave reflecting device 60. By utilizing time-domain functions, the processing unit 111 can distinguish between reflected waves at the electromagnetic wave reflecting device 60, reflected waves at the inner wall of the anechoic chamber 101, and direct waves.

[0072] The reflected wave at the electromagnetic wave reflecting device 60 is a radio wave transmitted from the transmitting antenna 115Tx and reflected by the electromagnetic wave reflecting device 60 to reach the receiving antenna 115Rx. The reflected wave at the inner wall of the anechoic chamber 101 is a radio wave transmitted from the transmitting antenna 115Tx and reflected by the inner wall of the anechoic chamber 101 to reach the receiving antenna 115Rx. The direct wave is a radio wave transmitted from the transmitting antenna 115Tx and directly reaches the receiving antenna 115Rx.

[0073] Furthermore, in the power reflection efficiency calculation method of the embodiment, the power reflection coefficient is calculated based on the received power. This processing can be performed by either the processing unit 111 of VNA 110 or the processing unit 121 of PC 120, or it can be shared by both processing units 111 and 121. Here, as an example, the method by which the processing unit 111 of VNA 110 calculates the power reflection coefficient based on the received power will be described. That is, here, as an example, the method by which the processing unit 111 of VNA 110 performs the calculation processing based on the power reflection efficiency calculation method will be described. Moreover, details of the power reflection efficiency calculation method will be provided later. Figures 6 to 8 Please provide an explanation.

[0074] <Memory 112>

[0075] The memory 112 stores the programs, data, etc. required for the processing unit 111 of the VNA 110 to perform calculations based on the power reflection efficiency calculation method.

[0076] <PC120>

[0077] PC120 has a built-in computer system for implementing the processing unit 121 and the memory 122. The computer system is implemented using a computer that includes a CPU, RAM, ROM, input / output interfaces, and an internal bus. The processing unit 121 is represented as a functional module that executes programs executed by the computer system of PC120. Furthermore, the memory 122 is a functional representation of the memory of the computer system of PC120.

[0078] As described above, in this embodiment, the processing unit 111 of VNA110 performs the calculation processing based on the power reflection efficiency calculation method. However, the processing unit 121 of PC120 can also perform the calculation processing based on the power reflection efficiency calculation method, or the calculation processing based on the power reflection efficiency calculation method can be shared by the processing units 111 and 121. The memory 122 stores the programs, data, etc. required for the processing unit 121 to perform the processing.

[0079] <Calculation Method for Power Reflection Efficiency in the Implementation Scheme>

[0080] Figure 7A as well as Figure 7B This is a diagram illustrating an example of a method for calculating the power reflection efficiency of an implementation scheme. In Figure 7A as well as Figure 7B It shows the relationship with Figures 1 to 5 Universal XYZ coordinates.

[0081] In Figure 7A and Figure 7B The positional relationship of the transmitting antenna 115Tx, the receiving antenna 115Rx, and the electromagnetic wave reflecting device 60 is simplified in a two-dimensional plane. Hereinafter, the electromagnetic wave reflecting device 60 with a metasurface will sometimes be referred to as electromagnetic wave reflecting device 60A, and the electromagnetic wave reflecting device 60 with a normal reflecting surface will sometimes be referred to as electromagnetic wave reflecting device 60B. Unless otherwise specified, electromagnetic wave reflecting devices 60A and 60B will be simply referred to as electromagnetic wave reflecting device 60.

[0082] Furthermore, when calculating the reflection efficiency of electromagnetic wave reflecting devices 60A and 60B, the reflection coefficient, calculated based on the received power measured in the electromagnetic wave reflecting device 60, which is made of a completely conductive material, is used. Hereinafter, the electromagnetic wave reflecting device 60, made of a completely conductive material, will be referred to as electromagnetic wave reflecting device 60C. Electromagnetic wave reflecting device 60C is an example of a reflector having a metallic reflective surface. For electromagnetic wave reflecting device 60C, any reflective surface that is flat and metallic is acceptable; as an example, an aluminum metal plate can be used as electromagnetic wave reflecting device 60C. Furthermore, since any reflective surface that is flat and metallic is acceptable, a reflector with aluminum foil adhered to a component such as a resin substrate can also be used as electromagnetic wave reflecting device 60C.

[0083] exist Figure 7A An electromagnetic wave reflecting device 60A with a metasurface is shown, in Figure 7B An electromagnetic wave reflecting device 60B with a regular reflecting surface is shown. Furthermore, an electromagnetic wave reflecting device 60C, constructed entirely of conductor, performs mirror reflection similarly to the electromagnetic wave reflecting device 60B, thus... Figure 7B In the middle, it is referred to as electromagnetic wave reflecting device 60B (60) or 60C.

[0084] <Details of the method for calculating the power reflection efficiency in the implementation method>

[0085] like Figure 7A As shown, in the case of electromagnetic wave reflecting device 60A, as an example, the angles and distances of electromagnetic wave reflecting device 60A, transmitting antenna 115Tx, and receiving antenna 115Rx are preset such that transmitting antenna 115Tx is located in a direction with an incident angle of 0 degrees relative to electromagnetic wave reflecting device 60A, and receiving antenna 115Rx is located in a direction with a reflection angle of θ degrees when the radio wave is incident at an incident angle of 0 degrees. Angle θ is the angle formed by transmitting antenna 115Tx and receiving antenna 115Rx relative to electromagnetic wave reflecting device 60A. Figure 7A The normal to the reflecting surface is shown by a dashed line. The distance between the electromagnetic wave reflecting device 60A and the transmitting antenna 115Tx on the path of the incident wave is equal to the distance between the electromagnetic wave reflecting device 60A and the receiving antenna 115Rx on the path of the reflected wave. As an example, in Figure 7A In this electromagnetic wave reflecting device 60A, the normal to the reflecting surface faces horizontally. Furthermore, the angle of incidence may not be 0 degrees. The electromagnetic wave reflecting device 60A reflects the electromagnetic waves in a direction offset by θ degrees relative to the angle of incidence.

[0086] Furthermore, when measuring the received power of the electromagnetic wave reflecting device 60C under the same reflection conditions as the electromagnetic wave reflecting device 60A, such as Figure 7BAs shown, without changing the positions of the transmitting antenna 115Tx and the receiving antenna 115Rx, the angle of the electromagnetic wave reflecting device 60C is adjusted so that the direction of the normal to the reflecting surface of the electromagnetic wave reflecting device 60C passes through... Figure 7A The center of angle θ in the equation. Therefore, for the electromagnetic wave reflecting device 60C, with incident and reflection angles of φ degrees, θ = 2φ holds. Angle 2φ is the angle formed by the transmitting antenna 115Tx and the receiving antenna 115Rx relative to the electromagnetic wave reflecting device 60C. The distance between the electromagnetic wave reflecting device 60A and the transmitting antenna 115Tx on the path of the incident wave is equal to the distance between the electromagnetic wave reflecting device 60A and the receiving antenna 115Rx on the path of the reflected wave.

[0087] Thus, the so-called identical reflection conditions refer to: Figure 7A The angle θ in Figure 7B The sum of the incident angle φ and the reflected angle φ (2φ) is the same, and Figure 7A The distance between the electromagnetic wave reflecting device 60A and the transmitting antenna 115Tx and the receiving antenna 115Rx is the same. Figure 7B The electromagnetic wave reflecting device 60C is equidistant from the transmitting antenna 115Tx and the receiving antenna 115Rx.

[0088] Thus, under the same reflection conditions, the received power P1 of the reflected wave reflected by the electromagnetic wave reflecting device 60A and the received power P2 of the reflected wave reflected by the electromagnetic wave reflecting device 60C are measured. The power reflection coefficient Γ1 is calculated based on the received power P1, and the power reflection coefficient Γ2 is calculated based on the received power P2.

[0089] Then, by using the power reflection coefficients Γ1 and Γ2 calculated for electromagnetic wave reflecting devices 60A and 60C under the same reflection conditions, the power reflection coefficient Γ1 is divided by the power reflection coefficient Γ2 to calculate the power reflection efficiency H of electromagnetic wave reflecting device 60A. Thus, by normalizing the power reflection coefficient Γ1 of electromagnetic wave reflecting device 60A using the power reflection coefficient Γ2 of electromagnetic wave reflecting device 60C, which is composed of a completely conductive conductor, the power reflection efficiency H of electromagnetic wave reflecting device 60A is calculated.

[0090] The electromagnetic wave reflecting device 60C, made entirely of conductors, exhibits mirror reflection, resulting in equal incident and reflection angles. However, the electromagnetic wave reflecting device 60A, with its metasurface, has different incident and reflection angles. Therefore, it requires correction to the power reflection efficiency H (=Γ1 / Γ2), calculated based on the power reflection coefficients Γ1 and Γ2 obtained under the same reflection conditions for both devices 60A and 60C. The power reflection efficiency H of the electromagnetic wave reflecting device 60A with its metasurface is obtained by dividing Γ1 / Γ2 by the correction value.

[0091] If the reflection electric field at an ideal metasurface with no reflection loss is denoted as E MR Let the reflected electric field at the reflecting surface, which is composed of a perfectly conductive surface, be E. PEC Then the correction value ε p It can be made by |E MR / E PEC | 2 express.

[0092] |E MR / E PEC | It is represented by the following formula (1) or formula (2).

[0093]

[0094]

[0095] Here, θ is the angle of incidence onto the metasurface, and φ is the reflection angle in the case of normal reflection. If the reflection angle of the metasurface is set to θ = 50° or θr = 50°, and the angle of incidence is set to θi = 0°, then the reflection angle of normal reflection is φ = 25°, and the correction value ε p It is 0.7826.

[0096] In addition, here, using Figure 7A as well as Figure 7B The method for determining the power reflection efficiency H of an electromagnetic wave reflecting device 60A with a metasurface is explained. In the case of an electromagnetic wave reflecting device 60B with a normal reflecting surface, such as... Figure 7B In this way, the received power is measured and the power reflection coefficient Γ2 based on the received power is calculated under reflection conditions where both the incident angle and the reflection angle are φ. Therefore, correction based on radar cross-section differences is not required, as is the case with the electromagnetic wave reflecting device 60A with a metasurface.

[0097] Under the same reflection conditions, the received power P1 of the reflected wave reflected by electromagnetic wave reflecting device 60B and the received power P2 of the reflected wave reflected by electromagnetic wave reflecting device 60C are measured. The power reflection coefficient Γ1 is calculated based on the received power P1, and the power reflection coefficient Γ2 is calculated based on the received power P2. Then, by using the power reflection coefficients Γ1 and Γ2 calculated for electromagnetic wave reflecting devices 60A and 60C under the same reflection conditions, the power reflection coefficient Γ1 is divided by the power reflection coefficient Γ2, thereby enabling the calculation of the power reflection efficiency H (=Γ1 / Γ2) of electromagnetic wave reflecting device 60B.

[0098] <Flowchart>

[0099] Figure 8This is a flowchart illustrating an example of the processing of the method for measuring received power and the method for calculating power reflection efficiency according to the embodiment. Here, as an example, it is executed by the processing unit 111 of VNA 110. Figure 8 The processing is shown. Figure 8 The processing shown is performed by the processing unit 111 executing a receiving power measurement program and a power reflection efficiency calculation program that implements a receiving power measurement method and a power reflection efficiency calculation method.

[0100] The processing unit 111 controls the transmitting circuit unit to transmit radio waves from the transmitting antenna 115Tx in a specified frequency band selected from a band of 1MHz or higher and 300GHz or lower, so that the radio waves are incident on the electromagnetic wave reflecting device 60 (60A or 60B) at a first specified incident angle (step S1). The first specified incident angle is, for example, 0 degrees in the case of the electromagnetic wave reflecting device 60A, and in the case of the electromagnetic wave reflecting device 60B, it is the incident angle (φ) determined based on the positional relationship between the transmitting antenna 115Tx and the receiving antenna 115Rx. The incident angle determined based on the positional relationship between the transmitting antenna 115Tx and the receiving antenna 115Rx is an angle specified by the design of the electromagnetic wave reflecting device 60B. Step S1 is an example of process 1.

[0101] Using a receiving antenna 115Rx positioned relative to the electromagnetic wave reflecting device 60 (60A or 60B) at a first specified reflection angle, the reflected wave of the radio wave incident on the electromagnetic wave reflecting device 60 (60A or 60B) in the first step is received. The processing unit 111 measures the received power P1 within a specified frequency range (step S2). Step S2 is an example of step 2. The received power P1 is an example of the first received power. The first specified reflection angle is the reflection angle θ specified by the design of the electromagnetic wave reflecting device 60A in the case of the electromagnetic wave reflecting device 60A, and is the angle equal to the incident angle in step S1 in the case of the electromagnetic wave reflecting device 60B. The specified frequency range is a band that includes multiple measurement points based on time-domain functions and can be set in VNA 110. As an example, when the specified frequency band selected from a band of 1MHz or higher and 300GHz or lower is 28GHz, the specified frequency range is 22GHz to 40GHz, and the multiple measurement points are multiple frequencies set every 10MHz within the range of 22GHz to 40GHz.

[0102] The processing unit 111 controls the transmitting circuit unit to transmit radio waves of the same specified frequency band as in step S1 from the transmitting antenna 115Tx, causing them to be incident on the electromagnetic wave reflecting device 60C at a second specified incident angle (step S3). The second specified incident angle is half the reflection angle θ specified by the design of the electromagnetic wave reflecting device 60A in step S1, and is equal to the first specified incident angle for the electromagnetic wave reflecting device 60B in step S1 when the electromagnetic wave reflecting device 60B is used. Step S3 is an example of process 1.

[0103] Using a receiving antenna 115Rx positioned relative to the electromagnetic wave reflecting device 60C at the second specified reflection angle, the reflected wave of the radio wave incident on the electromagnetic wave reflecting device 60C in the third step is received. The processing unit 111 measures the received power P2 within a specified frequency range (step S4). Step S4 is an example of step 4. The received power P2 is an example of the second received power. The second specified reflection angle is half the reflection angle θ of the electromagnetic wave reflecting device 60A when it is used in step S2, and equal to the first specified reflection angle of the electromagnetic wave reflecting device 60B in step S2 when it is used in step S2.

[0104] Furthermore, for the processing of steps S1 to S4, the processing of steps S1 and S2 can also be performed after the processing of steps S3 and S4.

[0105] The positions of the electromagnetic wave reflecting devices 60 (60A or 60B) in steps S1 and S2 relative to the transmitting antenna 115Tx and the receiving antenna 115Rx are equal to the positions of the electromagnetic wave reflecting devices 60C in steps S3 and S4 relative to the transmitting antenna 115Tx and the receiving antenna 115Rx. Furthermore, as an example, the positions of the electromagnetic wave reflecting devices 60A and 60B in steps S1 and S2 are the centroid positions of the electromagnetic wave reflecting devices 60A and 60B.

[0106] Processing unit 111 calculates the power reflection coefficient Γ1 of electromagnetic wave reflecting device 60 (60A or 60B) and the power reflection coefficient Γ2 of electromagnetic wave reflecting device 60C based on the received power P1 and P2 respectively (step S5). The power reflection coefficient Γ1 is calculated based on the reflection coefficient with received power P1 as the S-parameter, and the power reflection coefficient Γ2 is calculated based on the reflection coefficient with received power P2 as the S-parameter. Step S5 is an example of the fifth process. The power reflection coefficient Γ1 is an example of the first power reflection coefficient, and the power reflection coefficient Γ2 is an example of the second power reflection coefficient.

[0107] Processing unit 111 calculates the power reflection efficiency H of electromagnetic wave reflecting device 60 (60A or 60B) by dividing the power reflection coefficient Γ1 by the power reflection coefficient Γ2 (step S6). Step S6 is an example of the sixth process. In step S6, the power reflection efficiency H is calculated as Γ1 / Γ2.

[0108] In the case of electromagnetic wave reflecting device 60B, since the incident angle and the reflection angle are equal under normal reflection, no correction is required. Therefore, the power reflection efficiency H (=Γ1 / Γ2) calculated in step S6 is the power reflection efficiency of electromagnetic wave reflecting device 60B.

[0109] In the case of electromagnetic wave reflecting device 60B, since correction is required, processing unit 111 executes step S7.

[0110] Processing unit 111 divides the power reflection efficiency H (=Γ1 / Γ2) calculated for electromagnetic wave reflection device 60A in step S6 by the correction value |EMR / EPEC| 2 This corrects the power reflection efficiency H (=Γ1 / Γ2) of the electromagnetic wave reflecting device 60A (step S7). Step S7 is an example of the 7th process.

[0111] The above completes the series of processes in processing unit 111.

[0112] <Experimental Results (Part 1)>

[0113] Here, Examples 1 to 7 are explained as experimental results (Part 1).

[0114] <Example 1>

[0115] Example 1 is Example 1. An anechoic chamber 101 with a length of 5.0m, a width of 5.0m, and a height of 3.0m is used. Inside the anechoic chamber 101, a high-frequency signal at a specified frequency of 22.0GHz to 40.0GHz is output from a VNA 110. This signal propagates through space via a transmitting antenna 115Tx and is incident at an angle of +25° relative to an electromagnetic wave reflecting device 60C (i.e., an aluminum plate with a thickness of 5.0mm) made entirely of conductor. The reflected wave is received at a direction of -25° using a receiving antenna 115Rx. The received power P2 at 28.0GHz is measured at the terminal of the VNA 110 connected to the receiving antenna 115Rx. The dimensions of the aluminum plate (length in the X direction × length in the Y direction) are set to 0.2m × 0.2m. The distance from the transmitting antenna 115Tx to the aluminum plate along the path of the incident wave is set to 1.5m, and the distance from the aluminum plate to the receiving antenna 115Rx along the path of the reflected wave is set to 1.5m. The received power P2 becomes -29.7dB, and the power reflection coefficient Γ2 becomes 0.00108.

[0116] Next, the electromagnetic wave is incident at an angle of +25° to an electromagnetic wave reflector 60B with a normal reflective surface and a thickness of 5.0 mm via the transmitting antenna 115Tx. The reflected wave is received at a direction of -25° using the receiving antenna 115Rx. The received power P1 at 28.0 GHz is measured at the terminal of VNA 110 connected to the receiving antenna 115Rx. The dimensions (length in the X direction × length in the Y direction) of the electromagnetic wave reflector 60B are set to 0.2 m × 0.2 m. The distance from the transmitting antenna 115Tx to the electromagnetic wave reflector 60B along the path of the incident wave is set to 1.5 m, and the distance from the electromagnetic wave reflector 60B to the receiving antenna 115Rx along the path of the reflected wave is set to 1.5 m. The received power P1 is -29.8 dB, and the power reflection coefficient Γ1 is 0.00105. The ratio of Γ1 / Γ2 is 98.1%. This is consistent with the results of the previous electromagnetic field analysis.

[0117] <Example 2>

[0118] Example 2 is Example 2. An anechoic chamber 101 with a length of 5.0m, a width of 5.0m, and a height of 3.0m is used. Inside the anechoic chamber 101, a high-frequency signal at a specified frequency of 22.0GHz to 40.0GHz is output from a VNA 110. This signal propagates through space via a transmitting antenna 115Tx and is incident at an angle of +25° relative to an electromagnetic wave reflecting device 60C (i.e., an aluminum plate with a thickness of 5.0mm) made entirely of conductor. The reflected wave is received at a direction of -25° using a receiving antenna 115Rx. The received power P2 at 28.0GHz is measured at the terminal of the VNA 110 connected to the receiving antenna 115Rx. The dimensions of the aluminum plate (length in the X direction × length in the Y direction) are set to 0.2m × 0.2m. The distance from the transmitting antenna 115Tx to the aluminum plate along the path of the incident wave is set to 1.5m, and the distance from the aluminum plate to the receiving antenna 115Rx along the path of the reflected wave is set to 1.5m. The received power P2 becomes -29.7dB, and the power reflection coefficient Γ2 becomes 0.00108.

[0119] Next, an electromagnetic wave is incident at an angle of 0° to an electromagnetic wave reflector 60A with a metasurface and a thickness of 5.0 mm via a transmitting antenna 115Tx, propagating through space. The reflected wave is received at a direction of +50° using a receiving antenna 115Rx, and the received power at 28.0 GHz is measured at the terminal of VNA 110 connected to the receiving antenna 115Rx. The dimensions (length in the X direction × length in the Y direction) of the electromagnetic wave reflector 60A are set to 0.2 m × 0.2 m. The distance from the transmitting antenna 115Tx to the electromagnetic wave reflector along the path of the incident wave is set to 1.5 m, and the distance from the electromagnetic wave reflector to the receiving antenna 115Rx along the path of the reflected wave is set to 1.5 m. The received power P1 is -30.8 dB, and the power reflection coefficient Γ1 is 0.00082. The ratio of Γ1 / Γ2 is 75.9%. The correction value is 0.96, therefore the corrected power reflection efficiency is 79.1%. This is consistent with the results of the prior electromagnetic field analysis.

[0120] <Example 3>

[0121] Example 3 is Example 3. An anechoic chamber 101 with a length of 5.0m, a width of 5.0m, and a height of 3.0m is used. Inside the anechoic chamber 101, a high-frequency signal at a specified frequency of 22.0GHz to 40.0GHz is output from a VNA 110. This signal propagates through space via a transmitting antenna 115Tx and is incident at an angle of +15° relative to an electromagnetic wave reflecting device 60C (i.e., an aluminum plate with a thickness of 5.0mm) made entirely of conductor. The reflected wave is received at a direction of -15° using a receiving antenna 115Rx. The received power P2 at 28.0GHz is measured at the terminal of the VNA 110 connected to the receiving antenna 115Rx. The dimensions of the aluminum plate (length in the X direction × length in the Y direction) are set to 0.3m × 0.3m. The distance from the transmitting antenna 115Tx to the aluminum plate along the path of the incident wave is set to 3.0m, and the distance from the aluminum plate to the receiving antenna 115Rx along the path of the reflected wave is also set to 3.0m. The received power P2 becomes -29.7dB, and the power reflection coefficient Γ2 becomes 0.00108.

[0122] Next, an electromagnetic wave is incident at an angle of 0° to an electromagnetic wave reflector 60A with a metasurface and a thickness of 5.0 mm via a transmitting antenna 115Tx, propagating through space. The reflected wave is received at a direction of +30° using a receiving antenna 115Rx, and the received power P1 at 28.0 GHz is measured at the terminal of VNA 110 connected to the receiving antenna 115Rx. The dimensions (length in the X direction × length in the Y direction) of the electromagnetic wave reflector 60A are set to 0.3 m × 0.3 m. The distance from the transmitting antenna 115Tx to the electromagnetic wave reflector 60A along the path of the incident wave is set to 1.5 m, and the distance from the electromagnetic wave reflector 60A to the receiving antenna 115Rx along the path of the reflected wave is set to 1.5 m. The received power P1 is -30.2 dB, and the power reflection coefficient Γ1 is 0.00095. The ratio of Γ1 / Γ2 is 88.0%. The correction value is 0.98, therefore the corrected power reflection efficiency is 89.8%. This is consistent with the results of the prior electromagnetic field analysis.

[0123] <Example 4>

[0124] Example 4 is Example 4. An anechoic chamber 101 with a length of 5.0m, a width of 5.0m, and a height of 3.0m is used. Inside the anechoic chamber 101, a high-frequency signal at a specified frequency of 22.0GHz to 40.0GHz is output from a VNA 110. This signal propagates through space via a transmitting antenna 115Tx and is incident at an angle of +15° relative to an electromagnetic wave reflecting device 60C (i.e., an aluminum plate with a thickness of 5.0mm) made entirely of conductor. The reflected wave is received at a direction of -15° using a receiving antenna 115Rx. The received power at 28.0GHz is measured at the terminal of the VNA 110 connected to the receiving antenna 115Rx. The dimensions of the aluminum plate (length in the X direction × length in the Y direction) are set to 0.5m × 0.2m. The distance from the transmitting antenna 115Tx to the aluminum plate along the path of the incident wave is set to 8.0m, and the distance from the aluminum plate to the receiving antenna 115Rx along the path of the reflected wave is also set to 8.0m. The received power P2 becomes -29.7dB, and the power reflection coefficient Γ2 becomes 0.00108.

[0125] Next, an electromagnetic wave is incident at an angle of 0° to an electromagnetic wave reflector 60A with a metasurface and a thickness of 5.0 mm via a transmitting antenna 115Tx. The reflected wave is received at a direction of +45° using a receiving antenna 115Rx, and the received power at 28.0 GHz is measured at the terminal of VNA 110 connected to the receiving antenna 115Rx. The dimensions (length in the X direction × length in the Y direction) of the electromagnetic wave reflector 60A are set to 0.2 m × 0.2 m. The distance from the transmitting antenna 115Tx to the electromagnetic wave reflector 60A along the path of the incident wave is set to 1.5 m, and the distance from the electromagnetic wave reflector 60A to the receiving antenna 115Rx along the path of the reflected wave is set to 1.5 m. The received power P1 is -30.5 dB, and the power reflection coefficient Γ1 is 0.00089. Although the ratio of Γ1 / Γ2 is 82.4%, the correction value is 0.99, therefore the corrected power reflection efficiency is 83.2%. This is consistent with the results of the prior electromagnetic field analysis.

[0126] <Example 5>

[0127] Example 5 is a comparative example 1. An anechoic chamber 101 with a length of 5.0m, a width of 5.0m, and a height of 3.0m was used. Inside the anechoic chamber 101, a high-frequency signal with a specified frequency range of 22.0GHz to 40.0GHz was output from a VNA 110. This signal propagated through space via a transmitting antenna 115Tx and was incident at an angle of +25.0° relative to an electromagnetic wave reflecting device 60C (i.e., an aluminum plate with a thickness of 5.0mm) made entirely of conductors. The reflected wave was received at a direction of -25.0° using a receiving antenna 115Rx. The received power at 28.0GHz was measured at the terminal of the VNA 110 connected to the receiving antenna 115Rx. The dimensions of the aluminum plate (length in the X direction × length in the Y direction) were set to 0.3m × 0.3m. The distance from the transmitting antenna 115Tx to the aluminum plate along the path of the incident wave was set to 1.0m, and the distance from the aluminum plate to the receiving antenna 115Rx along the path of the reflected wave was also set to 1.0m. The received power becomes -29.5dB, and the power reflection coefficient Γ2 becomes 0.00112.

[0128] Next, an electromagnetic wave was incident at an angle of 0° to an electromagnetic wave reflector 60A with a metasurface and a thickness of 5.0 mm via a transmitting antenna 115Tx. The reflected wave was received at a direction of +50° using a receiving antenna 115Rx, and the received power at 28.0 GHz was measured at the terminal of VNA 110 connected to the receiving antenna 115Rx. The dimensions of the electromagnetic wave reflector (length in the X direction × length in the Y direction) were set to 0.3 m × 0.3 m, the distance from the transmitting antenna 115Tx to the electromagnetic wave reflector along the path of the incident wave was set to 0.3 m, and the distance from the electromagnetic wave reflector to the receiving antenna 115Rx along the path of the reflected wave was set to 0.3 m. The received power was -30.5 dB, and the power reflection coefficient was 0.00089 (Γ2). Although the ratio of Γ1 / Γ2 was 63.4%, the correction value was 2.12, which exceeded 1, so correction could not be performed. In addition, the results were inconsistent with the results of the previous electromagnetic field analysis.

[0129] <Example 6>

[0130] Example 6 is a comparative example 2. An anechoic chamber 101 with a length of 5.0m, a width of 5.0m, and a height of 3.0m was used. Inside the anechoic chamber 101, a high-frequency signal with a specified frequency range of 22.0GHz to 40.0GHz was output from a VNA 110. This signal propagated through space via a transmitting antenna 115Tx and was incident at an angle of +25° relative to an electromagnetic wave reflecting device 60C (i.e., an aluminum plate with a thickness of 5.0mm) made entirely of conductors. The reflected wave was received at a direction of -25° using a receiving antenna 115Rx. The received power at 28.0GHz was measured at the terminal of the VNA 110 connected to the receiving antenna 115Rx. The dimensions of the aluminum plate (length in the X direction × length in the Y direction) were set to 0.5m × 0.2m. The distance from the transmitting antenna 115Tx to the aluminum plate along the path of the incident wave was set to 2.9m, and the distance from the aluminum plate to the receiving antenna 115Rx along the path of the reflected wave was also set to 2.9m. The received power becomes -29.5dB, and the power reflection coefficient Γ2 becomes 0.00112.

[0131] Next, an electromagnetic wave is incident at an angle of 0° to an electromagnetic wave reflector 60A with a metasurface and a thickness of 5.0 mm via a transmitting antenna 115Tx. The reflected wave is received at a direction of +50° using a receiving antenna 115Rx, and the received power at 28.0 GHz is measured at the terminal of VNA 110 connected to the receiving antenna 115Rx. The dimensions (length in the X direction × length in the Y direction) of the electromagnetic wave reflector 60A are set to 0.3 m × 0.3 m. The distance from the transmitting antenna 115Tx to the electromagnetic wave reflector 60A along the path of the incident wave is set to 0.3 m, and the distance from the electromagnetic wave reflector 60A to the receiving antenna 115Rx along the path of the reflected wave is set to 0.3 m. The received power P1 is -30.9 dB, and the power reflection coefficient Γ1 is 0.00081. The ratio of Γ1 / Γ2 is 72.3%, and the correction value is 2.12. Therefore, the correction value exceeds 1, and correction cannot be performed. Furthermore, the results are inconsistent with those obtained from prior electromagnetic field analysis.

[0132] <Example 7>

[0133] Example 7 is a comparative example 3. An anechoic chamber 101 with a length of 5.0m, a width of 5.0m, and a height of 3.0m was used. Inside the anechoic chamber 101, a high-frequency signal with a specified frequency range of 22.0GHz to 40.0GHz was output from a VNA 110. This signal propagated through space via a transmitting antenna 115Tx and was incident at an angle of +30° relative to an electromagnetic wave reflecting device 60C (i.e., an aluminum plate with a thickness of 5.0mm) made entirely of conductors. The reflected wave was received at a direction of -30° using a receiving antenna 115Rx. The received power at 28.0GHz was measured at the terminal of the VNA 110 connected to the receiving antenna 115Rx. The dimensions of the aluminum plate (length in the X direction × length in the Y direction) were set to 0.5m × 0.2m. The distance from the transmitting antenna 115Tx to the aluminum plate along the path of the incident wave was set to 2.0m, and the distance from the aluminum plate to the receiving antenna 115Rx along the path of the reflected wave was also set to 2.0m. The received power P2 becomes -29.5dB, and the power reflection coefficient Γ2 becomes 0.00112.

[0134] Next, an electromagnetic wave is incident at an angle of 0° to an electromagnetic wave reflector 60A with a metasurface and a thickness of 5.0 mm via a transmitting antenna 115Tx. The reflected wave is received at a direction of +60° using a receiving antenna 115Rx, and the received power at 28.0 GHz is measured at the terminal of the VNA 110 connected to the receiving antenna 115Rx. The dimensions of the electromagnetic wave reflector 60A (length in the X direction × length in the Y direction) are set to 0.5 m × 0.2 m. The distance from the transmitting antenna 115Tx to the electromagnetic wave reflector 60A along the path of the incident wave is set to 0.3 m, and the distance from the electromagnetic wave reflector 60A to the receiving antenna 115Rx along the path of the reflected wave is set to 0.3 m. The received power is -30.5 dB, and the power reflection coefficient Γ1 is 0.00089. The ratio of Γ1 / Γ2 is 63.4%, and the correction value is 2.02. Therefore, the correction value exceeds 1, and correction cannot be performed. Furthermore, the results are inconsistent with those obtained from prior electromagnetic field analysis.

[0135] <Experimental Results (Part 2)>

[0136] Unlike Examples 2 to 7, for the electromagnetic wave reflecting device 60A with a metasurface, various dimensions (length in the X direction × length in the Y direction) were set, and the distances between the transmitting antenna 115Tx and the electromagnetic wave reflecting device 60A on the incident wave path and between the electromagnetic wave reflecting device 60A and the receiving antenna 115Rx on the reflected wave path were measured when the correction value was less than 1 and did not change significantly even with slight deviations in the measured distance. Figure 9A as well as Figure 9B The results are shown.

[0137] Figure 9A as well as Figure 9B This figure shows an example of the measurement results for an electromagnetic wave reflecting device 60A, specifically the distances from the transmitting antenna 115Tx to the electromagnetic wave reflecting device 60A along the incident wave path and from the electromagnetic wave reflecting device 60A to the receiving antenna 115Rx along the reflected wave path, when the correction value is below 1 and there is no significant change even with slight deviations in the measured distance. "No significant change" refers to the degree to which deviations in the measured distance do not cause practical obstacles to calculating the power reflection efficiency. Figure 9C This diagram illustrates an example of the structure of the reflecting surface of the electromagnetic wave reflecting device 60A. In the quadrilateral reflecting surface of the electromagnetic wave reflecting device 60A, the length (width) in the X direction is X (m), and the length in the Y direction is Y (m). Figure 9CIn this configuration, the transmitting antenna 115Tx is located at an incident angle of 0 degrees relative to the electromagnetic wave reflecting device 60A, and the receiving antenna 115Rx is located at a reflection angle of θ degrees when the radio wave is incident at an incident angle of 0 degrees. As an example, the reflection angle θ is... Figure 9C The direction indicated by the middle arrow is taken as positive, and the opposite side is taken as negative.

[0138] exist Figure 9A The diagram shows the electromagnetic wave reflecting device 60A with its X and Y directions set to be the same. The distance L between the electromagnetic wave reflecting device 60A and the transmitting antenna 115Tx and receiving antenna 115Rx is measured when the correction value is less than 1 and the distance does not change significantly even with slight deviations in the measured distance (see reference). Figure 9C An example of the measurement results. The distance L is the measurement result of the distance from the transmitting antenna 115Tx to the electromagnetic wave reflecting device 60A on the path of the incident wave and the distance from the electromagnetic wave reflecting device 60A to the receiving antenna 115Rx on the path of the reflected wave when the correction value is less than 1 and the distance does not change significantly even if the measured distance is slightly deviated.

[0139] With the length of the electromagnetic wave reflecting device 60A in both the X and Y directions being 0.3m, the distance L is greater than 2.85m. That is, with the length of the electromagnetic wave reflecting device 60A in both the X and Y directions being 0.3m, if the distance L is less than 2.85m, the correction value is greater than 1. Considering the antenna, sample settings, and angle accuracy, sometimes even a slight deviation in the measured distance can make the correction value much smaller than the actual appropriate value. However, if the distance L is greater than 2.85m, the correction value becomes less than 1, and even a slight deviation in the measured distance does not cause a significant change.

[0140] If the lengths of the electromagnetic wave reflecting device 60A in the X and Y directions are increased from 0.3m to 1.0m, the distance L increases from 2.85m to 31.5m. That is, when the lengths of the electromagnetic wave reflecting device 60A in the X and Y directions are 1.0m, if the distance L is less than 31.5m, the correction value is greater than 1. Sometimes, even a slight deviation in the measured distance will result in a correction value much smaller than the appropriate value. However, if the distance L is greater than 31.5m, the correction value becomes less than 1, and even a slight deviation in the measured distance will not cause a significant change.

[0141] exist Figure 9B An example is shown of the measurement results of the distance L between the electromagnetic wave reflecting device 60A and the transmitting antenna 115Tx and the receiving antenna 115Rx when the lengths in the X and Y directions are set to be the same or different, and the correction value is less than 1 and the distance does not change significantly even if the measurement distance is slightly offset.

[0142] When the length of the electromagnetic wave reflecting device 60A in the X direction is 0.2m and the length in the Y direction is 0.4m, the distance L between the electromagnetic wave reflecting device 60A and the transmitting antenna 115Tx and the receiving antenna 115Rx is 1.3m, where the correction value is less than 1 and does not change significantly even with a slight deviation in the measured distance. That is, when the length of the electromagnetic wave reflecting device 60A in the X direction is 0.2m and the length in the Y direction is 0.4m, if the distance L is less than 1.30m, the correction value is greater than 1, and sometimes even a slight deviation in the measured distance will result in a correction value much smaller than the appropriate value. However, if the distance L is greater than 1.30m, the correction value becomes less than 1, and does not change significantly even with a slight deviation in the measured distance.

[0143] When the length of the electromagnetic wave reflecting device 60A in the X direction is 0.4m and the length in the Y direction is 0.2m, if the distance L is less than 5.00m, the correction value is greater than 1; if the distance L is greater than 5.00m, the correction value becomes less than 1, and even if the measured distance deviates slightly, there is no significant change. The distance L in this case is approximately four times longer than the distance L when the length of the electromagnetic wave reflecting device 60A in the X direction is 0.2m and the length in the Y direction is 0.4m.

[0144] Furthermore, when the length of the electromagnetic wave reflecting device 60A in both the X and Y directions is 0.2m, if the distance L is less than 1.30m, the correction value is greater than 1. Sometimes, even a slight deviation in the measured distance can cause the correction value to be much smaller than the appropriate value. However, if the distance L is greater than 1.30m, the correction value becomes less than 1, and even a slight deviation in the measured distance does not cause a significant change. The distance L in this case is the same as the distance L when the length of the electromagnetic wave reflecting device 60A in both the X and Y directions is 0.2m.

[0145] Furthermore, when the length of the electromagnetic wave reflecting device 60A in both the X and Y directions is 0.4m, if the distance L is less than 5.00m, the correction value is greater than 1. Sometimes, even a slight deviation in the measured distance can cause the correction value to be much smaller than the appropriate value. However, if the distance L is greater than 5.00m, the correction value becomes less than 1, and even a slight deviation in the measured distance does not cause a significant change. The distance L in this case is the same as the distance L when the length of the electromagnetic wave reflecting device 60A in both the X and Y directions is 0.4m and 0.2m.

[0146] Depend on Figure 9B The results show that the length of the electromagnetic wave reflecting device 60A in the X direction has a greater impact on the change of distance L than the length in the Y direction.

[0147] Figure 10 This means fitting a quadratic curve to... Figure 9A A diagram illustrating an example of the results obtained. Figure 10 In the diagram, the horizontal axis represents the length (m) of the electromagnetic wave reflecting device 60A in the X and Y directions. Here, the lengths of the electromagnetic wave reflecting device 60A in the X and Y directions are equal (X = Y). The vertical axis represents the distance L.

[0148] The fitted quadratic curve is represented by the following equation (3).

[0149]

[0150] When the lengths of the electromagnetic wave reflecting device 60A in the X and Y directions are equal and both are X (m), if the distance L is greater than the distance L expressed by equation (3), the correction value becomes less than 1 and does not change much even if the measured distance is slightly offset. Therefore, the relationship between the length (m) of the electromagnetic wave reflecting device 60A in the X and Y directions and the distance L is sufficient as long as the following equation (4) holds.

[0151]

[0152] That is, when the lengths of the electromagnetic wave reflecting device 60A in the X and Y directions are equal (X=Y), if the distance L between the electromagnetic wave reflecting device 60A and the transmitting antenna 115Tx and the receiving antenna 115Rx is set in such a way that the distance L satisfies the relationship of Equation (4), then the power reflection efficiency H (=Γ1 / Γ2) obtained for the electromagnetic wave reflecting device 60A can be corrected in the same way as the results of Examples 2 to 4 in the experimental results (Part 1).

[0153] In addition, according to Figure 9B As a result, the length of the electromagnetic wave reflecting device 60A in the X direction has a greater impact on the change in distance L. Therefore, for equation (4), it can be considered as follows: Figure 9C As shown, when the length (width) of the quadrilateral reflective surface of the electromagnetic wave reflector 60A in the X direction is X (m), if the distance L between the electromagnetic wave reflector 60A and the transmitting antenna 115Tx and the receiving antenna 115Rx is set in such a way that the distance L satisfies the relationship of Equation (4), then the power reflection efficiency H (=Γ1 / Γ2) obtained for the electromagnetic wave reflector 60A can be corrected in the same way as the results of Examples 2 to 4 in the experimental results (Part 1).

[0154] <Effect>

[0155] The method for measuring received power includes: a first step (step S1), in an anechoic chamber 101 equipped with a VNA 110 connected to a transmitting antenna 115Tx and a receiving antenna 115Rx, both fixed in relative positions, transmitting a radio wave from the transmitting antenna 115Tx into a predetermined frequency band selected from a band between 1 MHz and 300 GHz, so that it is incident on an electromagnetic wave reflecting device 60 (60A or 60B) at a first specified incident angle; a second step (step S2), using the receiving antenna 115Rx positioned at the first specified reflection angle relative to the electromagnetic wave reflecting device 60 (60A or 60B), receiving the radio wave incident on the electromagnetic wave reflecting device 60 (60A or 60B) in the first step (60A or 60B) at the first specified reflection angle. The process involves: 1) Reflecting the electromagnetic wave 60 (60A or 60B) using a VNA 110 and measuring the first received power within a specified frequency range; 2) Transmitting a radio wave of a specified frequency band from a transmitting antenna 115Tx inside an anechoic chamber 101, causing it to be incident at a second specified angle of incidence relative to an electromagnetic wave reflecting device 60C made of a completely conductive material; 3) Receiving the reflected wave of the electromagnetic wave reflecting device 60C incident in the third step using a receiving antenna 115Rx positioned relative to the electromagnetic wave reflecting device 60C made of a completely conductive material at the second specified angle of reflection, and measuring the second received power within a specified frequency range using a VNA 110. Therefore, using a VNA 110, the received power can be measured under the same reflection conditions for electromagnetic wave reflecting devices 60 (60A or 60B) having metasurfaces or regular reflective surfaces and electromagnetic wave reflecting devices 60C made of a completely conductive material.

[0156] Therefore, a method for measuring received power can be provided that can appropriately measure the received power in an electromagnetic wave reflecting device 60 having a metasurface or a regular reflective surface. Furthermore, a procedure for measuring received power can be provided that can appropriately measure the received power in an electromagnetic wave reflecting device 60 having a metasurface or a regular reflective surface.

[0157] Furthermore, the angles formed by the transmitting antenna 115Tx and the receiving antenna 115Rx relative to the electromagnetic wave reflecting device 60 (60A or 60B) in the first step (step S1) and the second step (step S2) can also be equal to the angles formed by the transmitting antenna 115Tx and the receiving antenna 115Rx relative to the electromagnetic wave reflecting device 60C, which is made of a completely conductive material, in the third step (step S3) and the fourth step (step S4). Therefore, the received power can be measured more reliably using the VNA110 under the same reflection conditions.

[0158] The method for calculating power reflection efficiency includes: any of the above-described methods for measuring received power; step 5 (S5), calculating the first power reflection coefficient Γ1 of the electromagnetic wave reflecting device 60 (60A or 60B) and the second power reflection coefficient Γ2 of the electromagnetic wave reflecting device 60C, which is composed entirely of conductors, based on the first received power P1 and the second received power P2; and step 6 (S6), calculating the power reflection efficiency Γ1 / Γ2 of the electromagnetic wave reflecting device 60 (60A or 60B) by dividing the first power reflection coefficient Γ1 by the second power reflection coefficient Γ2. Therefore, the power reflection efficiency Γ1 / Γ2 of the electromagnetic wave reflecting device 60 (60A or 60B) can be calculated using VNA110. Furthermore, by executing the power reflection efficiency calculation program, the power reflection efficiency Γ1 / Γ2 of the electromagnetic wave reflecting device 60 (60A or 60B) can be calculated using VNA110.

[0159] Furthermore, the electromagnetic wave reflecting device 60 is an electromagnetic wave reflecting device 60B that performs specular reflection, and the first specified incident angle, the first specified reflection angle, the second specified incident angle, and the second specified reflection angle can all be equal. Therefore, using VNA110, the power reflection efficiency Γ1 / Γ2 of the electromagnetic wave reflecting device 60 (60A or 60B) can be calculated more reliably under the same reflection conditions.

[0160] Furthermore, the electromagnetic wave reflecting device 60 is a non-mirror reflection electromagnetic wave reflecting device 60A, and the sum of the first specified incident angle and the first specified reflection angle can be equal to the sum of the second specified incident angle and the second specified reflection angle. Therefore, the power reflection efficiency Γ1 / Γ2 of the electromagnetic wave reflecting device 60A can be calculated more reliably under the same reflection conditions using the VNA110.

[0161] Additionally, a seventh step (S7) may be included, which involves using a correction value |EMR / EPEC| derived from the reflected electric field EMR at an ideal metasurface with no reflection loss and the reflected electric field EPEC at a reflective surface composed entirely of conductors. 2 The power reflection efficiency Γ1 / Γ2 of the non-mirror reflection electromagnetic wave reflection device 60A is divided by the correction value |EMR / EPEC|. 2 This allows for the correction of the power reflection efficiency Γ1 / Γ2 of the electromagnetic wave reflecting device 60A, which performs non-mirror reflection. Therefore, the VNA110 can be used to appropriately correct the power reflection efficiency Γ1 / Γ2 of the electromagnetic wave reflecting device 60A, where the incident angle and reflection angle are different.

[0162] In addition, the reflecting surface of the electromagnetic wave reflecting device 60A that performs non-mirror reflection is a quadrilateral with a width of X (m). The distance on the path of the incident wave between the electromagnetic wave reflecting device 60A that performs non-mirror reflection and the transmitting antenna 115Tx is equal to the distance on the path of the reflected wave between the electromagnetic wave reflecting device 60A that performs non-mirror reflection and the receiving antenna 115Rx, both of which are L (m). The condition for the distance L when the correction value is less than 1 can also be expressed by the following formula (5).

[0163]

[0164] By setting the length X (m) and distance L of the reflective surface of the electromagnetic wave reflector 60A that performs non-mirror reflection in a manner that satisfies Equation (5), the correction value becomes less than 1 and does not change significantly even if the measured distance is slightly offset, thus enabling the correction of the power reflection efficiency H (=Γ1 / Γ2) calculated for the electromagnetic wave reflector 60A.

[0165] The above describes an exemplary method for measuring received power and a method for calculating power reflection efficiency. However, this disclosure is not limited to the specific implementation method disclosed, but various modifications and alterations can be made without departing from the scope of the claims.

[0166] Furthermore, this international application claims priority based on Japanese Patent Application No. 2023-203013, filed on November 30, 2023, the entire contents of which are incorporated herein by reference.

[0167] Explanation of reference numerals in the attached figures

[0168] 10, 10-1, 10-2, 10A...Reflective panel; 15...Conductive pattern; 60, 60-1, 60-2, 60-3...Electromagnetic wave reflecting device; 60A...Electromagnetic wave reflecting device; 60B...Electromagnetic wave reflecting device; 60C...Electromagnetic wave reflecting device; 100...Electromagnetic wave reflecting enclosure; 101...Anechoic chamber; 110...VNA; 111...Processing unit; 112...Memory; 115Tx...Transmitting antenna; 115Rx...Receiving antenna; 120...PC; 121...Processing unit; 122...Memory.

Claims

1. A method for measuring received power, wherein, include: In the first step, inside an anechoic chamber equipped with a vector network analyzer connected to a transmitting antenna and a receiving antenna whose relative positions are fixed, radio waves of a specified frequency band selected from a band of 1 MHz or higher and 300 GHz or lower are transmitted from the transmitting antenna, so that they are incident on an electromagnetic wave reflecting device at a first specified angle of incidence. In the second step, the receiving antenna, which is positioned in a direction with a first specified reflection angle relative to the electromagnetic wave reflecting device, receives the reflected wave of the electromagnetic wave incident on the electromagnetic wave reflecting device in the first step, and uses the vector network analyzer to determine the first received power within a specified frequency range. In the third step, inside the anechoic chamber, radio waves of the specified frequency band are transmitted from the transmitting antenna, causing them to be incident at a second specified angle of incidence relative to a reflector having a metallic reflective surface; and In the fourth step, the receiving antenna, positioned at a second specified reflection angle relative to the reflector having the metal reflective surface, receives the reflected wave of the radio wave incident on the metal reflective surface in the third step, and uses the vector network analyzer to determine the second received power within the specified frequency range.

2. The method for measuring received power according to claim 1, wherein, The angles formed by the transmitting antenna and the receiving antenna relative to the electromagnetic wave reflecting device in the first and second steps are equal to the angles formed by the transmitting antenna and the receiving antenna relative to the reflector having the metal reflective surface in the third and fourth steps.

3. A method for calculating power reflection efficiency. in, include: The method for measuring the received power as described in claim 1 or 2; In the fifth step, based on the first received power A and the second received power B, the first power reflection coefficient Γ1 of the electromagnetic wave reflecting device and the second power reflection coefficient Γ2 of the reflector having the metal reflective surface are calculated respectively; and In the sixth step, the power reflection efficiency Γ1 / Γ2 of the electromagnetic wave reflection device is calculated by dividing the first power reflection coefficient Γ1 by the second power reflection coefficient Γ2.

4. The method for calculating power reflection efficiency according to claim 3, wherein, The electromagnetic wave reflecting device is a specular reflection device. The first specified incident angle, the first specified reflection angle, the second specified incident angle, and the second specified reflection angle are all equal.

5. The method for calculating power reflection efficiency according to claim 3, wherein, The electromagnetic wave reflecting device is a non-specular reflection device. The sum of the first specified incident angle and the first specified reflection angle is equal to the sum of the second specified incident angle and the second specified reflection angle.

6. The method for calculating power reflection efficiency according to claim 5, wherein, Also includes: Step 7 involves using the correction value |EMR / EPEC| derived from the reflected electric field EMR at an ideal metasurface with no reflection loss and the reflected electric field EPEC at a reflective surface composed entirely of conductors. 2 The power reflection efficiency Γ1 / Γ2 of the electromagnetic wave reflection device that performs non-mirror reflection is divided by the correction value |EMR / EPEC|. 2 This corrects the power reflection efficiency Γ1 / Γ2 of the electromagnetic wave reflecting device that performs non-mirror reflection.

7. The method for calculating power reflection efficiency according to claim 6, wherein, The reflecting surface of the electromagnetic wave reflecting device that performs non-mirror reflection is a quadrilateral with a width of X. The distance along the path of the incident wave between the electromagnetic wave reflecting device (non-mirror reflection) and the transmitting antenna is equal to the distance along the path of the reflected wave between the electromagnetic wave reflecting device (non-mirror reflection) and the receiving antenna, both being L. The condition for the distance L when the correction value becomes less than 1 is expressed by the following equation (1). ， The units for X and L are meters (m).

8. A procedure for measuring received power, wherein, To make the computer perform: In the first step, inside an anechoic chamber equipped with a vector network analyzer connected to a transmitting antenna and a receiving antenna whose relative positions are fixed, radio waves of a specified frequency band selected from a band of 1 MHz or higher and 300 GHz or lower are transmitted from the transmitting antenna, so that they are incident on an electromagnetic wave reflecting device at a first specified angle of incidence. In the second step, the receiving antenna, which is positioned in a direction with a first specified reflection angle relative to the electromagnetic wave reflecting device, receives the reflected wave of the electromagnetic wave incident on the electromagnetic wave reflecting device in the first step, and uses the vector network analyzer to determine the first received power within a specified frequency range. In the third step, inside the anechoic chamber, radio waves of the specified frequency band are transmitted from the transmitting antenna, causing them to be incident at a second specified angle of incidence relative to a reflector having a metallic reflective surface; and In the fourth step, the receiving antenna, positioned at a second specified reflection angle relative to the reflector having the metal reflective surface, receives the reflected wave of the radio wave incident on the metal reflective surface in the third step, and uses the vector network analyzer to determine the second received power within the specified frequency range.

9. A program for calculating power reflection efficiency, wherein, To make the computer perform: The procedure for measuring the received power as described in claim 8; In the fifth step, based on the first received power A and the second received power B, the first power reflection coefficient Γ1 of the electromagnetic wave reflecting device and the second power reflection coefficient Γ2 of the reflector having the metal reflective surface are calculated respectively; and In the sixth step, the power reflection efficiency Γ1 / Γ2 of the electromagnetic wave reflection device is calculated by dividing the first power reflection coefficient Γ1 by the second power reflection coefficient Γ2.

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