Inspection device for electric wave reflection device and method for inspecting same

Abstract

The present invention provides an inspection device for an electric wave reflection device, the inspection device including: an antenna that transmits / receives an electric wave to / from an electric wave reflection device including a plurality of reflection elements each including a patch electrode and a common electrode; a stage on which the electric wave reflection device is placed and which is disposed so as to oppose the antenna; and a control unit which is disposed between the antenna and the stage, has an opening portion through which electric wave passes, and controls an electric wave radiation area in the electric wave reflection device by means of the opening portion.

Description

Radio wave reflecting device inspection device and inspection method

[0001] The present invention relates to an inspection device and an inspection method for a radio wave reflecting device.

[0002] Radio wave reflecting devices are used to deliver radio waves to areas (dead zones) where radio waves are difficult to reach, such as the valleys between high-rise buildings. Examples of radio wave reflecting devices that have been disclosed include a configuration in which a main array element (dipole element), a subarray element (parasitic element), and a common electrode (ground electrode) are arranged with a dielectric substrate sandwiched between them, with the subarray element being disposed close to the main array element (Patent Document 1), and a configuration in which the array element and the common electrode (ground electrode) sandwich a dielectric substrate, with the common electrode having a periodic loop shape (Patent Document 2).

[0003] JP 2011-019021 A JP 2010-226695 A

[0004] A radio wave reflecting device uses a dielectric substrate. However, if the dielectric substrate is replaced with a liquid crystal layer, the dielectric anisotropy of the liquid crystal material can be utilized, enabling the directionality of the reflected waves to be varied. A radio wave reflecting device using a liquid crystal material has a configuration in which reflecting elements are arranged in a matrix, similar to a planar array antenna with a patch array. A radio wave reflecting device controls the direction of radio wave reflection by changing the dielectric constant of the liquid crystal layer that forms each reflecting element through the voltage applied between the electrodes. However, if the correct voltage is not applied to each electrode of the reflecting element and the correct voltage is not applied to the liquid crystal, the radio wave reflection direction cannot be controlled to the desired direction. Therefore, it is necessary to inspect each reflecting element for proper operation. Furthermore, visual inspection of reflecting elements is difficult, so inspection using radio waves is required.

[0005] In view of such problems, one object of one embodiment of the present invention is to provide an inspection device that can inspect the quality of individual reflecting elements that make up a radio wave reflecting device without relying on vision.

[0006] An inspection device for a radio wave reflecting device according to one embodiment of the present invention includes a radio wave reflecting device having a plurality of reflecting elements each having a patch electrode and a common electrode, an antenna for transmitting and receiving radio waves, a stage positioned opposite the antenna on which the radio wave reflecting device is placed, and a control unit positioned between the antenna and the stage, having an opening through which radio waves pass and which controls the irradiation area of ​​the radio waves in the radio wave reflecting device using the opening.

[0007] A method for inspecting a radio wave reflecting device according to one embodiment of the present invention is a method for inspecting a radio wave reflecting device having a plurality of reflecting elements, each of which has a patch electrode and a common electrode, in which a first reflecting element of the plurality of reflecting elements is superimposed on an opening through which radio waves emitted from the antenna pass, in a control section between the antenna and a stage facing the antenna and on which the radio wave reflecting device is placed, radio waves are emitted from the antenna to the first reflecting element, the radio waves reflected by the first reflecting element are received by the antenna, and the quality of the first reflecting element is determined based on the amount of phase change of the received radio waves.

[0008] 1 shows a plan view of a reflecting element used in a radio wave reflecting device according to one embodiment of the present invention. FIG. 1 shows a cross-sectional view of a reflecting element used in a radio wave reflecting device according to one embodiment of the present invention. FIG. 2 shows a state in which a reflecting element used in a radio wave reflecting device according to one embodiment of the present invention is operating, showing a state in which no voltage is applied between the patch electrode and the common electrode. FIG. 3 shows a state in which a reflecting element used in a radio wave reflecting device according to one embodiment of the present invention is operating, showing a state in which a voltage is applied between the patch electrode and the common electrode. FIG. 4 shows the configuration of a radio wave reflecting device according to one embodiment of the present invention. FIG. 5 shows a schematic diagram illustrating how the direction of travel of a reflected wave is changed by a radio wave reflecting device according to one embodiment of the present invention. FIG. 6 shows the configuration of a radio wave reflecting device according to one embodiment of the present invention. FIG. 7 shows a cross-sectional view of a reflecting element in a radio wave reflecting device according to one embodiment of the present invention. FIG. 8 is a cross-sectional view of an inspection device for a radio wave reflecting device according to one embodiment of the present invention. FIG. 9 is a perspective view of a control unit and a stage of an inspection device for a radio wave reflecting device according to one embodiment of the present invention. FIG. 10 is a plan view of a control unit of an inspection device for a radio wave reflecting device according to one embodiment of the present invention. FIG. 11 is a cross-sectional view of an inspection device for a radio wave reflecting device according to one embodiment of the present invention. FIG. 12 is a flowchart illustrating an inspection method for a radio wave reflecting device using an inspection device for a radio wave reflecting device according to one embodiment of the present invention.

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention can be implemented in many different forms, and should not be construed as being limited to the description of the following exemplary embodiments. For clarity of explanation, the drawings may show the width, thickness, shape, etc. of each part schematically compared to the actual form. However, these are merely examples and are not intended to limit the interpretation of the present invention. Furthermore, in this specification and each drawing, elements similar to those previously described with reference to the previous drawings are designated by the same reference numerals (or reference numerals with a, b, etc. suffixed thereto), and detailed descriptions may be omitted as appropriate. Furthermore, the letters "first" and "second" attached to each element are convenient labels used to distinguish each element and have no further meaning unless otherwise specified.

[0010] In this specification, when a component or region is referred to as being "on (or under)" another component or region, unless otherwise specified, this includes not only the case where it is directly above (or directly under) the other component or region, but also the case where it is above (or under) the other component or region, i.e., the case where another component is included between the component or region and above (or under) the other component or region.

[0011] 1A and 1B show a reflecting element 102 used in a radio wave reflecting device 100 according to one embodiment of the present invention. Fig. 1A shows a plan view of the reflecting element 102 as seen from above (the side where radio waves are incident), and Fig. 1B shows a cross-sectional view between A1 and A2 shown in the plan view.

[0012] 1A and 1B , the reflective element 102 includes a dielectric substrate 104, a counter substrate 106, a patch electrode 108, a common electrode 110, a first alignment film 112a, a second alignment film 112b, and a liquid crystal layer 114. Within the reflective element 102, the dielectric substrate 104 can be considered as a single layer, i.e., a dielectric layer. The patch electrode 108 is provided on the dielectric substrate 104, and the common electrode 110 is provided on the counter substrate 106. The common electrode 110 is disposed on the rear surface of the patch electrode 108. A first alignment film 112a is provided on the dielectric substrate 104 to cover the patch electrode 108, and a second alignment film 112b is provided on the counter substrate 106 to cover the common electrode 110. The patch electrode 108 and the common electrode 110 are disposed opposite each other, with a liquid crystal layer 114 disposed between them. A first alignment film 112 a is interposed between the patch electrode 108 and the liquid crystal layer 114 , and a second alignment film 112 b is interposed between the common electrode 110 and the liquid crystal layer 114 .

[0013] The patch electrode 108 preferably has a shape that is symmetrical with respect to the vertically and horizontally polarized waves of the incident radio wave, and has a square or circular shape in a planar view. FIG. 1A shows a case where the patch electrode 108 is square in a planar view. The shape of the common electrode 110 is not particularly limited, and it has a shape that extends over substantially the entire surface of the opposing substrate 106 so as to have a larger area than the patch electrode 108. The material for forming the patch electrode 108 and the common electrode 110 is not particularly limited, and they may be formed using conductive metals or metal oxides. A first wiring 118 may be provided on the dielectric substrate 104. The first wiring 118 is connected to the patch electrode 108. The first wiring 118 can be used to apply a control signal to the patch electrode 108. Furthermore, when multiple reflecting elements are arranged, the first wiring 118 can be used to connect a patch electrode to an adjacent patch electrode.

[0014] Although not shown in FIGS. 1A and 1B , the dielectric substrate 104 and the counter substrate 106 are bonded together with a sealant. The dielectric substrate 104 and the counter substrate 106 are disposed opposite each other with a gap therebetween, and the liquid crystal layer 114 is provided within the area surrounded by the sealant. The liquid crystal layer 114 is provided to fill the gap between the dielectric substrate 104 and the counter substrate 106. The gap between the dielectric substrate 104 and the counter substrate 106 is 20 to 100 μm, for example, 50 μm. A patch electrode 108, a common electrode 110, a first alignment film 112 a, and a second alignment film 112 b are provided between the dielectric substrate 104 and the counter substrate 106. Therefore, to be precise, the gap between the first alignment film 112 a and the second alignment film 112 b provided on the dielectric substrate 104 and the counter substrate 106, respectively, is the thickness of the liquid crystal layer 114. Although not shown in FIG. 1B, a spacer may be provided between the dielectric substrate 104 and the opposing substrate 106 to maintain a constant gap therebetween.

[0015] A control signal that controls the orientation of liquid crystal molecules in the liquid crystal layer 114 is applied to the patch electrode 108. The control signal is a DC voltage signal or a polarity inversion signal in which positive and negative DC voltages alternate. The common electrode 110 is grounded or receives a voltage at an intermediate level of the polarity inversion signal. Application of the control signal to the patch electrode 108 changes the orientation state of the liquid crystal molecules contained in the liquid crystal layer 114. A liquid crystal material having dielectric anisotropy is used for the liquid crystal layer 114. For example, nematic liquid crystal, smectic liquid crystal, cholesteric liquid crystal, or discotic liquid crystal can be used for the liquid crystal layer 114. The dielectric constant of the liquid crystal layer 114 with dielectric anisotropy changes depending on the change in the orientation state of the liquid crystal molecules. The reflective element 102 can change the dielectric constant of the liquid crystal layer 114 by applying a control signal to the patch electrode 108, thereby delaying the phase of the reflected wave when reflecting radio waves.

[0016] The frequency bands of radio waves reflected by the reflective element 102 are the very high frequency (VHF) band, the ultra high frequency (UHF) band, the super high frequency (SHF) band, the submillimeter wave (THF) band, and the extra high frequency (EHF) band. The liquid crystal molecules in the liquid crystal layer 114 change their orientation in response to a control signal applied to the patch electrode 108, but the orientation hardly changes with the frequency of the radio waves irradiated onto the patch electrode 108. Therefore, the reflective element 102 can control the phase of the reflected radio waves without being affected by the radio waves themselves.

[0017] FIG. 2A shows a state (referred to as the "first state") in which no voltage is applied between the patch electrode 108 and the common electrode 110. FIG. 2A shows a case in which the first alignment film 112a and the second alignment film 112b are horizontal alignment films. In the first state, the long axes of the liquid crystal molecules 116 are aligned horizontally relative to the surfaces of the patch electrode 108 and the common electrode 110 by the first alignment film 112a and the second alignment film 112b. FIG. 2B shows a state (referred to as the "second state") in which a control signal (voltage signal) is applied to the patch electrode 108. In the second state, the liquid crystal molecules 116 are oriented with their long axes perpendicular to the surfaces of the patch electrode 108 and the common electrode 110 due to the action of an electric field. The angle at which the long axes of the liquid crystal molecules 116 are aligned can be set to a direction intermediate between the horizontal and vertical directions depending on the magnitude of the control signal applied to the patch electrode 108 (the magnitude of the voltage Vn (n is a natural number) between the common electrode and the patch electrode).

[0018] When the liquid crystal molecules 116 have positive dielectric anisotropy, the dielectric constant is greater in the second state than in the first state. When the liquid crystal molecules 116 have negative dielectric anisotropy, the apparent dielectric constant is smaller in the second state than in the first state. The liquid crystal layer 114, which has dielectric anisotropy, can also be considered a variable dielectric layer. The reflective element 102 can control the phase of the reflected wave to delay (or not delay) by utilizing the dielectric anisotropy of the liquid crystal layer 114.

[0019] The reflecting element 102 is used as a radio wave reflector that reflects radio waves in a predetermined direction. It is preferable that the reflecting element 102 attenuates the amplitude of the reflected radio waves as little as possible. As is clear from the structure shown in Fig. 1B, when radio waves propagating through the air are reflected by the reflecting element 102, the radio waves pass through the dielectric substrate 104 twice. The dielectric substrate 104 is formed of a dielectric material such as glass or resin.

[0020] 2. Radio Wave Reflector Next, the structure of a radio wave reflector in which reflecting elements are integrated will be described.

[0021] 2-1. Radio Wave Reflecting Device A (Single-Axis Reflection Control) FIG. 3 shows the configuration of a radio wave reflecting device 100a according to one embodiment of the present invention. The radio wave reflecting device 100 has a radio wave reflecting plate 120. The radio wave reflecting plate 120 is composed of a plurality of reflecting elements 102. The plurality of reflecting elements 102 are arranged, for example, in a column direction (the X-axis direction shown in FIG. 3 ) and a row direction (the Y-axis direction shown in FIG. 3 ) that intersects the column direction. The reflecting elements 102 are arranged so that the patch electrodes 108 face the radio wave incident surface. The radio wave reflecting plate 120 is flat, and a plurality of patch electrodes 108 are arranged in a matrix within the flat surface.

[0022] The radio wave reflecting device 100a has a structure in which multiple reflecting elements 102 are integrated on a single dielectric substrate 104. As shown in FIG. 3 , the radio wave reflecting device 100 has a structure in which the dielectric substrate 104 on which multiple patch electrodes 108 are arranged and the counter substrate 106 on which a common electrode 110 is provided are stacked, with a liquid crystal layer (not shown) provided between the two substrates. The radio wave reflecting plate 120 is formed in the area where the multiple patch electrodes 108 and the common electrode 110 overlap. The cross-sectional structure of the radio wave reflecting plate 120, when viewed from the individual patch electrodes 108, is the same as the structure of the reflecting element 102 shown in FIG. 1B . The dielectric substrate 104 and the counter substrate 106 are bonded together with a sealant 128, and a liquid crystal layer (not shown) is provided in the area inside the sealant 128.

[0023] The dielectric substrate 104 has a region facing the opposing substrate 106, as well as a peripheral region 122 extending outward from the opposing substrate 106. A first drive circuit 124 and a terminal section 126 are provided in the peripheral region 122. The first drive circuit 124 outputs a control signal to the patch electrode 108. The terminal section 126 is a region for forming a connection with an external circuit, and is connected to, for example, a flexible printed circuit board (FPC) (not shown). A signal for controlling the first drive circuit 124 is input to the terminal section 126.

[0024] As described above, a plurality of patch electrodes 108 are arranged in the column direction (X-axis direction) and row direction (Y-axis direction) on the dielectric substrate 104. A plurality of first wirings 118 extending in the row direction (Y-axis direction) are also arranged on the dielectric substrate 104. Each of the plurality of first wirings 118 is electrically connected to a plurality of patch electrodes 108 arranged in the row direction (Y-axis direction). In other words, the plurality of patch electrodes 108 arranged in the row direction (Y-axis direction) are connected by the first wirings 118. The radio wave reflecting plate 120 has a configuration in which a plurality of patch electrode arrays connected by the first wirings 118 are arranged in a row in the column direction (X-axis direction).

[0025] The plurality of first wirings 118 arranged on the radio wave reflecting plate 120 extend into the peripheral region 122 and are connected to a first driving circuit 124. The first driving circuit 124 is capable of outputting control signals of different voltage levels to each of the plurality of first wirings 118. As a result, in the radio wave reflecting plate 120, a control signal is applied to each of the plurality of patch electrodes 108 arranged in the column direction (X-axis direction) and row direction (Y-axis direction) for each column (each patch electrode 108 arranged in the row direction (Y-axis direction)).

[0026] The radio wave reflecting device 100a applies a control signal to each set of a plurality of patch electrodes 108 arranged in the row direction (Y-axis direction), thereby controlling the reflection direction of the reflected waves of the radio waves incident on the radio wave reflector 120. In other words, the radio wave reflecting device 100a can control the propagation direction of the reflected waves of the radio waves irradiated to the radio wave reflector 120 in the left and right directions in the drawing, centered on a reflection axis VR parallel to the row direction (Y-axis direction).

[0027] 4 shows a schematic diagram illustrating how the direction of propagation of a reflected wave changes depending on the two reflecting elements 102. When radio waves are incident on reflecting elements 102a and 102b with the same phase, different control signals (V1≠V2) are applied to reflecting elements 102a and 102b, resulting in a larger phase change in the reflected wave from reflecting element 102b than from reflecting element 102a. As a result, the phase of reflected wave R1 reflected from reflecting element 102a differs from the phase of reflected wave R2 reflected from reflecting element 102b (in FIG. 4, the phase of reflected wave R2 leads the phase of reflected wave R1), and the apparent direction of propagation of the reflected wave changes obliquely.

[0028] This principle can be applied to the radio wave reflecting device 100a shown in FIG. 3, and for example, by controlling the amount of phase change by the reflecting elements for each row, the reflection direction can be controlled in one axis direction.

[0029] 2-2. Radio wave reflecting device B (two-axis reflection control) The radio wave reflecting device 100a shown in Fig. 3 has a single reflection axis VR, so it is possible to control the reflection angle in the direction of the reflection axis VR as the axis of rotation. In contrast, this embodiment shows an example of a radio wave reflecting device 100b that can perform two-axis reflection control. The following explanation will focus on the differences from the radio wave reflecting device 100a.

[0030] The radio wave reflecting device 100b has a plurality of second wirings 132 extending in the column direction (X-axis direction). The plurality of first wirings 118 and the plurality of second wirings 132 are arranged to intersect with an insulating layer (not shown) sandwiched therebetween. The plurality of first wirings 118 are connected to a first drive circuit 124, and the plurality of second wirings 132 are connected to a second drive circuit 130. The second drive circuit 130 outputs a scanning signal.

[0031] 5B shows an enlarged view of an arrangement 102m of four patch electrodes 108 and two first wirings 118 and second wirings 132. Each of the four patch electrodes 108 is provided with a switching element 134. The switching (on and off) of the switching element 134 is controlled by a scanning signal applied to the second wiring 132. When the switching element 134 is turned on, the patch electrode 108 is electrically connected to the first wiring 118 and a control signal is applied to it. The switching element 134 is formed of, for example, a thin-film transistor. With this configuration, it is possible to select a plurality of patch electrodes 108 arranged in the column direction (X-axis direction) for each row and apply control signals of different voltage levels to each row.

[0032] 5A can control the direction of travel of the reflected waves of radio waves irradiated onto the radio wave reflector 120 in the left-right direction of the drawing, centered on a reflection axis VR parallel to the row direction (Y-axis direction), and can also control the direction of travel of the reflected waves in the up-down direction of the drawing, centered on a reflection axis HR parallel to the column direction (X-axis direction). In other words, because the radio wave reflecting device 100b has a reflection axis VR parallel to the row direction (Y-axis direction) and a reflection axis HR parallel to the column direction (X-axis direction), it can control the reflection angle in the direction about the reflection axis VR as the rotation axis and in the direction about the reflection axis HR as the rotation axis.

[0033] This principle can be applied to the radio wave reflecting device 100b shown in FIG. 5A. For example, by independently controlling the amount of phase change by the reflecting elements in both columns and rows, the reflection direction can be controlled in both uniaxial and biaxial directions.

[0034] 6 shows an example of the cross-sectional structure of a reflective element 102 in which a switching element 134 is connected to a patch electrode 108. The switching element 134 is provided on a dielectric substrate 104. The switching element 134 is a transistor and has a stacked structure of a first gate electrode 138, a first gate insulating layer 140, a semiconductor layer 142, a second gate insulating layer 146, and a second gate electrode 148. An undercoat layer 136 may be provided between the first gate electrode 138 and the dielectric substrate 104. A first wiring 118 is provided between the first gate insulating layer 140 and the second gate insulating layer 146. The first wiring 118 is provided so as to be in contact with the semiconductor layer 142. A first connection wiring 144 is provided in the same layer as the conductive layer that forms the first wiring 118. The first connection wiring 144 is provided so as to be in contact with the semiconductor layer 142. The connection structure of the first wiring 118 and the first connection wiring 144 to the semiconductor layer 142 shows a structure in which one wiring is connected to the source of the transistor and the other wiring is connected to the drain.

[0035] A first interlayer insulating layer 150 is provided to cover the switching element 134. A second wiring 132 is provided on the first interlayer insulating layer 150. The second wiring 132 is connected to the second gate electrode 148 through a contact hole formed in the first interlayer insulating layer 150. Although not shown, the first gate electrode 138 and the second gate electrode 148 are electrically connected to each other in a region that does not overlap with the semiconductor layer 142. A second connection wiring 152 is provided on the first interlayer insulating layer 150 and is made of the same conductive layer as the second wiring 132. The second connection wiring 152 is connected to the first connection wiring 144 through a contact hole formed in the first interlayer insulating layer 150.

[0036] A second interlayer insulating layer 154 is provided to cover the second wiring 132 and the second connection wiring 152. Furthermore, a planarizing layer 156 is provided to fill in the step of the switching element 134. By providing the planarizing layer 156, the patch electrode 108 can be formed without being affected by the arrangement of the switching element 134. A passivation layer 158 is provided on the flat surface of the planarizing layer 156. The patch electrode 108 is provided on the passivation layer 158. The patch electrode 108 is connected to the second connection wiring 152 via a contact hole that penetrates the passivation layer 158, the planarizing layer 156, and the second interlayer insulating layer 154. A first alignment film 112a is provided on the patch electrode 108.

[0037] The counter substrate 106 is provided with a common electrode 110 and a second alignment film 112b, as in FIG. 1B . The surface of the dielectric substrate 104 on which the switching element 134 and the patch electrode 108 are provided faces the surface of the counter substrate on which the common electrode 110 is provided, and a liquid crystal layer 114 is provided therebetween. The thickness T of the dielectric substrate 104 can be defined as the length from the surface of the patch electrode 108 on the liquid crystal layer 114 side to the surface of the dielectric substrate 104 opposite the surface on which the patch electrode 108 is provided. In this case, the thickness of at least one insulating layer (undercoat layer 136, first gate insulating layer 140, second gate insulating layer 146, first interlayer insulating layer 150, second interlayer insulating layer 154, planarizing layer 156, passivation layer 158) between the patch electrode 108 and the dielectric substrate 104 can be taken into consideration.

[0038] The layers formed on the dielectric substrate 104 are formed using the following materials. The undercoat layer 136 is formed, for example, of a silicon oxide film. The first gate insulating layer 140 and the second gate insulating layer 146 are formed, for example, of a silicon oxide film or a stacked structure of a silicon oxide film and a silicon nitride film. The semiconductor layer is formed of a silicon semiconductor such as amorphous silicon or polycrystalline silicon, or an oxide semiconductor including a metal oxide such as indium oxide, zinc oxide, or gallium oxide. The first gate electrode 138 and the second gate electrode 148 may be formed, for example, of molybdenum (Mo), tungsten (W), or an alloy thereof. The first wiring 118, the second wiring 132, the first connection wiring 144, and the second connection wiring 152 are formed using a metal material such as titanium (Ti), aluminum (Al), or molybdenum (Mo). For example, they may be formed as a stacked structure of titanium (Ti), aluminum (Al), and titanium (Ti), or a stacked structure of molybdenum (Mo), aluminum (Al), and molybdenum (Mo). The planarization layer 156 is made of a resin material such as acrylic or polyimide. The passivation layer 158 is made of, for example, a silicon nitride film. The patch electrode 108 and the common electrode 110 are made of a metal film such as aluminum (Al) or copper (Cu).

[0039] 6 , by connecting the second wiring 132 to the gate of a transistor used as a switching element 134, connecting the first wiring 118 to one of the source and drain of the transistor, and connecting the patch electrode 108 to the other of the source and drain, a control signal can be applied to a predetermined patch electrode selected from the plurality of patch electrodes 108 arranged in a matrix. By providing the switching element 134 to each patch electrode 108 in the radio wave reflector 120, a control voltage can be applied to each patch electrode 108 arranged in a horizontal row along the first direction (X-axis direction) or each patch electrode 108 arranged in a vertical row along the second direction (Y-axis direction). For example, when the radio wave reflector 120 is upright, the reflection direction of the reflected wave can be controlled in the left-right and up-down directions.

[0040] 3. Inspection Device Next, an inspection device 200 used to inspect the radio wave reflecting device 100 will be described with reference to FIGS.

[0041] The inspection device 200 basically comprises an antenna 202, a control unit 204, and a stage 206. Fig. 7 is a cross-sectional view of the inspection device used to inspect a radio wave reflecting device according to one embodiment of the present invention. Fig. 8 is a perspective view of the inspection device used to inspect a radio wave reflecting device according to one embodiment of the present invention. Fig. 9 is a plan view of the control unit of the inspection device for a radio wave reflecting device according to one embodiment of the present invention.

[0042] [Antenna] The antenna 202 can transmit radio waves to the radio wave reflecting device 100 and receive radio waves reflected from the radio wave reflecting device 100. Specifically, the antenna 202 can radiate radio waves S1 to the radio wave reflecting plate 120 shown in Fig. 3 and Fig. 5A and receive radio waves SR1 reflected by the radio wave reflecting plate 120. More specifically, the antenna 202 can radiate radio waves (incident waves) to the reflecting element 102a shown in Fig. 4 and receive radio waves (reflected waves) reflected by the reflecting element 102a.

[0043] The antenna 202 is disposed in a position facing the stage 206. The antenna 202 is disposed so that the control unit 204 and the stage 206 are located in the direction in which the radio wave S1 is emitted. When the radio wave reflecting device 100 on the stage 206 is located in the far field, the antenna 202 faces the stage 206 directly.

[0044] The antenna 202 may be an antenna that transmits and receives radio waves in a fixed direction. For example, a directional antenna may be used for the antenna 202, and a monopolar antenna is preferable. More specifically, the antenna 202 may be a horn antenna, an array antenna, a parabolic antenna, a Yagi-Uda antenna, or the like.

[0045] [Control Unit 1] The control unit 204 can control the irradiation area of ​​the radio wave reflecting device 100 that is irradiated by the radio waves S1 emitted from the antenna 202. The control unit 204 is disposed between the antenna 202 and a stage 206 on which the radio wave reflecting device 100 is placed, and functions like a filter for the radio waves S1 irradiated from the antenna 202 to the radio wave reflecting device 100. The control unit 204 can block (absorb or reflect) or weaken radio waves S1 other than the radio waves S1 irradiating a specific area of ​​the radio wave reflecting device 100. The control unit 204 can cause the radio waves S1 radiated from the antenna 202 to be irradiated to a specific area of ​​the radio wave reflecting device 100, and can cause the antenna 202 to receive a specific radio wave SR1 reflected by the radio wave reflecting device 100. To ensure smooth transmission and reception of radio waves by the antenna 202, the control unit 204 is disposed parallel to the antenna 202 and the radio wave reflecting device 100 in a cross-sectional view. In addition, it is preferable that an opening 208 (described later) is disposed so as to face the patch electrode 108 of the reflecting element 102 of the antenna 202 and the radio wave reflecting device 100 in a cross-sectional view.

[0046] The control unit 204 has a function of controlling the radio waves S1 to be irradiated onto a specific region of the radio wave reflecting device 100, but by moving one or both of the control unit 204 and the stage 206 relatively, the irradiation region of the radio waves S1 can be scanned over the entire surface of the radio wave reflecting device 100. In other words, the specific region of the radio wave reflecting device 100 is not limited to one specific location, but by appropriately selecting a specific region within the radio wave reflecting device 100 by the control unit 204, the radio waves S1 radiated from the antenna 202 can be irradiated onto the selected specific region. In order to select a specific region within the radio wave reflecting device 100, the control unit 204 is movable on the stage 206, while the stage 206 is fixed in position.

[0047] On the other hand, the inspection device 200 may have a configuration in which the position of the control unit 204 is fixed and the stage 206 is movable. When the control unit 204 is fixed, the control unit 204 is disposed so that the distance DR1 from the antenna 202 to the control unit 204 satisfies the following formula 1. In this case, the half-value angle of the radio wave radiated from the antenna 202 is θ Ｈ[°], and the width of the control section 204 is D1 [mm]. Ｈ / 2)<D1 (Formula 1)

[0048] The distance DR1 from the antenna 202 to the control unit 204 that satisfies the above formula 1 is, for example, a half-value angle θ Ｈ When is 18°, it is 100 cm.

[0049] When the control unit 204 is fixed and the position of the control unit 204 satisfies the above formula 1, the width D1 of the control unit 204 is determined by the half-width θ of the radio wave S1 emitted from the antenna 202. Ｈ It is preferable that the width D1 of the control section 204 is larger than the half width θ Ｈ By being larger, it is possible to prevent high-gain radio waves S1 from irradiating areas other than the specific area of ​​the radio wave reflecting device 100, making it easier to distinguish between radio waves received by the antenna 202 that have been reflected from the specific area of ​​the radio wave reflecting device 100 and radio waves that have been reflected elsewhere.

[0050] Here, a description will be given of the basic configuration of the control unit 204. The control unit 204 has at least an opening 208 and a radio wave absorbing unit 210.

[0051] The opening 208 is a hole for irradiating radio waves to a specific region of the radio wave reflecting device 100. The opening 208 has a size that allows the radio waves S1 to be irradiated to at least one of the patch electrode 108 and the common electrode 110 of the reflecting element 102, and as described above, allows the radio waves S1 radiated from the antenna 202 and the radio waves SR1 reflected by the radio wave reflecting device 100 to pass through. The opening 208 is a hole that penetrates a specific region of the member that constitutes the control unit 204.

[0052] Opening 208 is a tunnel-shaped hole that passes through control unit 204 and can be made up of multiple side surfaces. If opening 208 is rectangular in plan view, it becomes a cavity shaped like a quadrangular prism and is made up of four rectangular side surfaces. If opening 208 is circular in plan view, it becomes a cavity shaped like a cylinder and is made up of one rectangular side surface.

[0053] The opening 208 does not have to be a tunnel-shaped hole that passes through the control unit 204. If the opening 208 is not a tunnel-shaped hole that passes through the control unit 204, the control unit 204 may be configured with a metasurface and the opening 208 may be configured with a dielectric. In this way, the control unit 204 may be configured to absorb or reflect radio waves, and the opening 208 may be configured to transmit radio waves. For example, the portion corresponding to the opening 208 may be configured with a dielectric layer, and the control unit 204 may be configured with a dielectric layer that absorbs or reflects radio waves. Also, for example, the control unit 204 may be configured with a metasurface, and the portion corresponding to the opening 208 may be configured with a dielectric layer.

[0054] The specific area of ​​the radio wave reflecting device 100 is the area occupied by one reflecting element 102 of the radio wave reflecting device 100 in a top view. As shown in Fig. 9, when the control unit 204 and the radio wave reflecting device 100 are superimposed, the opening 208 is sized to expose the patch electrode 108-1 of one reflecting element 102-1 of the radio wave reflecting device 100 in a top view, but not to expose the patch electrode 108-2 of the reflecting element 102-2 adjacent to the reflecting element 102-1 among the multiple reflecting elements. In Fig. 9, the reflecting element adjacent to the reflecting element 102-1 is the reflecting element 102-2, but the reflecting element adjacent to the reflecting element 102-1 that is irradiated with radio waves is not limited to the reflecting element 102-2, but is the reflecting element 102 surrounding the reflecting element 102-1.

[0055] In plan view, the opening 208 is smaller than the area occupied by the reflecting element 102 on the radio wave reflector 120 and smaller than the area of ​​the patch electrode 108 of the reflecting element 102. For example, as shown in Fig. 9 , when the patch electrode 108-1 of the reflecting element 102-1 and the opening 208 are square in shape, the width W1 of the opening 208 is smaller than the width W2 of the reflecting element 102, and the areas occupied by the opening 208 and the patch electrode 108 are larger and smaller, respectively. Although Fig. 9 shows the case where the opening 208 is square, the shape of the opening 208 may be any shape as long as it can surround one patch electrode 108.

[0056] The radio wave absorbing section 210 can prevent the radio waves S1 emitted from the antenna 202 from being irradiated onto the radio wave reflecting device 100 except for a specific region of the radio wave reflecting device 100. The radio wave absorbing section 210 is arranged to surround the opening 208. The radio wave absorbing section 210 has the opening 208. The radio wave absorbing section 210 is provided on at least one of the first surface 204AF facing the antenna 202 and the second surface 204AB facing the stage 206.

[0057] When the radio wave absorbing portion 210 is provided on the first surface 204AF, it is possible to absorb radio waves S1 emitted from the antenna 202 other than the radio waves S1 that pass through the opening 208. By absorbing the radio waves S1 other than the radio waves S1 that pass through the opening 208, it is possible to suppress or prevent the reception of radio waves reflected by the control portion 204 by the antenna 202.

[0058] When the radio wave absorbing portion 210 is provided on the second surface 204AB, it is possible to absorb the radio waves SR1 that are reflected at a specific region of the radio wave reflecting device 100 and do not pass through the opening 208 again. By absorbing the radio waves that do not pass through the opening 208 again, it is possible to cause the antenna 202 to selectively receive the radio waves SR1 that are reflected at a specific region of the radio wave reflecting device 100.

[0059] From the above, it is more preferable that the radio wave absorbing portion 210 is provided on both the first surface 204AF and the second surface 204AB. Alternatively, instead of providing the radio wave absorbing portion 210 on each of the first surface 204AF and the second surface 204AB, a single radio wave absorbing portion 210 may be provided for both the first surface 204AF and the second surface 204AB.

[0060] The radio wave absorbing section 210 includes a radio wave absorber. Alternatively, the radio wave absorbing section 210 is composed of a radio wave absorber. For example, a radio wave absorber that absorbs radio wave energy by magnetic loss in the material itself can be used. An example of the structure of a radio wave absorber that absorbs radio wave energy by magnetic loss is a structure in which powder of a magnetic material such as sendust or ferrite is kneaded into a sheet made of silicone or other rubber. Radio waves that enter a radio wave absorber that absorbs radio wave energy generate a magnetic field in the magnetic material. When the generated magnetic field is reduced to radio wave energy, part of the energy is lost, and the radio waves are absorbed.

[0061] Furthermore, the radio wave absorber may be, for example, a radio wave absorber having a structure that reflects radio waves on both the front and back surfaces. Examples of the structure of a radio wave absorber having a structure that reflects radio waves on both the front and back surfaces include a structure in which a metal plate such as carbonyl iron is provided on one side of a sheet made of silicone or other rubber. Radio wave absorbers having a structure that reflects radio waves on both the front and back surfaces are configured so that the phases of the radio waves reflected on the front and back surfaces are shifted by 180°, and therefore the radio waves reflected on the front and back surfaces cancel each other out and disappear.

[0062] In addition to the above, the radio wave absorber may be configured using a frequency selective surface (FFS).

[0063] [Stage] The stage 206 can be used to place the radio wave reflecting device 100. The stage 206 has a flat surface so that it can stably hold the radio wave reflecting device 100. The stage 206 may be provided with a fixing member for fixing the radio wave reflecting device 100, a vacuum chuck, or the like.

[0064] The stage 206 is movable, and can move the radio wave reflecting device 100. At this time, the stage 206 may be movable while the control unit 204 is fixed, or may be movable together with the control unit 204. Depending on the size of the radio wave reflecting device 100, the control unit 204 and the stage 206 can be appropriately selected and moved.

[0065] However, when the control unit 204 is movable, it is preferable that the radio wave reflecting device 100 placed on the stage 206 is located in the far field and directly opposite the antenna 202. When the control unit 204 is movable, this includes when the control unit 204 and the stage 206 are movable. When the antenna 202 and the radio wave reflecting device 100 are located in the far field, the directivity of the radio wave S1 irradiated to the entire radio wave reflecting device 100 remains almost unchanged. In this case, the distance DR3 from the antenna 202 to the radio wave reflecting device 100 shown in FIGS. 7 and 8 is, for example, 2×D1 ２ / λ [mm] or more, where D1 [mm] is the width of the radio wave reflecting device 100, and λ is the wavelength of the radio wave S1.

[0066] Furthermore, when the control unit 204 is fixed, the antenna 202 is disposed so that the distance DR3 from the antenna 202 to the radio wave reflecting device 100 placed on the stage 206 satisfies the following formula 2. In this case, the half-value angle of the radio wave radiated from the antenna 202 is θ Ｈ [°], and the width of the radio wave reflecting plate 120 of the radio wave reflecting device 100 is D2 [mm]. Ｈ / 2)<D2 (Formula 2)

[0067] When the distance DR1 from the antenna 202 to the control unit 204 satisfies the above formula 1, or when the distance DR3 from the antenna 202 to the radio wave reflector 120 placed on the stage 206 satisfies the above formula 2, the high-gain radio wave S1 can be used to irradiate a specific area of ​​the radio wave reflecting device 100.

[0068] Furthermore, the stage 206 can determine the distance DR2 from the control unit 204 to the radio wave reflector 120 by the radio wave absorber of the radio wave absorbing section 210. When a radio wave absorber that absorbs radio wave energy by magnetic loss of the material itself is used as the radio wave absorber, the control unit 204 and the radio wave reflecting device 100 placed on the stage 206 can be arranged in contact with each other. When a radio wave absorber with a structure that reflects radio waves on both the front and back surfaces is used as the radio wave absorber, it is preferable to set the distance DR2 to an extent that no coupling capacitance occurs between the control unit 204 and the radio wave reflecting device 100. For example, when the half-value angle θ ＨWhen the angle is 18°, the distance DR1 is 100 cm and the distance DR2 is 10 cm.

[0069] As shown by the arrows in Figures 7 and 8, the stage 206 is movable in a direction perpendicular to the direction in which the radio waves SR1 are emitted. The stage 206 is movable in the row direction (Y-axis direction) and column direction (X-axis direction) in which the plurality of reflecting elements 102 are arranged. The stage 206 is movable in units of one reflecting element 102 in the row direction and column direction in which the plurality of reflecting elements 102 are arranged. The stage 206 can also adjust the distance from the antenna 202, and can be moved in a direction toward or away from the antenna 202 (Z-axis direction). It is preferable that these movements of the stage 206 maintain a state in which the stage 206 and the antenna 202 face each other.

[0070] 4. Modifications [Control Unit 2] Next, a control unit 204a, which is a modification of the control unit 204, will be described with reference to Fig. 10. The control unit 204a differs from the control unit 204 shown in Fig. 7 in that conductors are arranged on the first surface 204AF and the second surface 204AB, the first surface 204AF is convex toward the antenna 202, and the second surface 204AB is convex toward the stage 206. Note that descriptions of configurations that are the same as or similar to those of the control unit 204 shown in Fig. 7 may be omitted.

[0071] The first surface 204AF is convex and projects toward the antenna 202. The second surface 204AB is convex and projects toward the stage 206. It is preferable that both the first surface 204AF and the second surface 204AB are convex.

[0072] 10, in a cross-sectional view, the control unit 204a has at least two ends in a direction intersecting the traveling direction of the radio waves S1 emitted from the antenna 202, and the length P1 between the two ends can be longer than the length P2 of the opening 208 in the traveling direction of the radio waves. The control unit 204a has a disk-like shape.

[0073] At least one surface of the first surface 204AF and the second surface 204AB is provided with a conductor. It is more preferable that the first surface 204AF and the second surface 204AB are provided with a conductor. The conductor may be made of a metal such as gold, silver, copper, aluminum, iron, or chromium.

[0074] Although not shown, the control portion 204a may include concentric notches on the first surface 204AF and the second surface 204AB. The control portion 204a may have a sawtooth shape in cross section. The control portion 204a may resemble, for example, a Fresnel lens and have an opening 208.

[0075] As described above, by having first surface 204AF be convex and provided with a conductor or be sawtooth-shaped, it is possible to reflect radio waves S1 emitted from antenna 202 that do not pass through opening 208, and cause the reflected radio waves SR2 to travel in a direction away from opening 208. Furthermore, by having second surface 204AB be convex and provided with a conductor or be sawtooth-shaped, it is possible to reflect radio waves SR1 reflected by radio wave reflecting device 100 that do not pass through opening 208, and cause the reflected radio waves SR3 to travel in a direction away from opening 208. As a result, even if radio waves SR2 and SR3 traveling in a direction away from opening 208 are received by antenna 202, they can be received at a time different from the time at which radio waves SR1 that pass through opening 208 are received.

[0076] As described above, the radio wave reflecting device inspection device 200 has the antenna 202, a stage for placing the radio wave reflecting device 100, the opening 208, and a control unit for controlling the area where the radio waves are irradiated onto the radio wave reflecting device, so that it can irradiate radio waves S1 onto each of the multiple reflecting elements 102 of the radio wave reflecting device 100 and receive radio waves SR1 reflected by each of them. By transmitting and receiving radio waves between the antenna 202 and each reflecting element 102, it is possible to inspect whether each reflecting element is operating normally.

[0077] 5. Inspection Method A method for inspecting a radio wave reflecting device using the inspection device 200 according to one embodiment of the present invention will be described with reference to Figures 7 to 9 and 11. Figure 11 is a flowchart showing a method for inspecting a radio wave reflecting device using the inspection device according to one embodiment of the present invention.

[0078] 11 , the radio wave reflecting device 100 is placed on the stage 206. When the patch electrode 108 of the reflecting element 102 is on the upper surface and the common electrode 110 is on the lower surface, the radio wave reflecting device 100 is placed so that the upper surface faces the antenna 202 and the lower surface faces the stage 206.

[0079] 11 , the opening 208 of the control unit 204 is overlapped with one of the reflective elements 102. As described above, the opening 208 of the control unit 204 may be moved to overlap the opening 208 of the control unit 204 with one of the reflective elements 102, or the stage 206 may be moved to overlap one of the reflective elements 102 with the opening 208 of the control unit 204. The overlapping of the opening 208 with one of the reflective elements 102 may be performed such that at least the patch electrode 108 of an adjacent reflective element 102 is not exposed from the opening 208, as shown in FIG.

[0080] 11, the stage 206 is moved up or down so that the distance DR2 from the radio wave reflecting device 100 to the control unit 204 becomes the above-mentioned distance. Here, the order of step S300 and step S200 may be reversed.

[0081] 11, a desired voltage is applied between the patch electrode 108 and the common electrode 110 of the radio wave reflecting device 100. At this time, the voltage is applied between the patch electrode 108 and the common electrode 110 so that the radio waves reflected by the radio wave reflecting device 100 have the same phase difference between the adjacent reflecting elements 102.

[0082] 11, radio waves S1 are radiated from the antenna 202 to the radio wave reflecting device 100. The radio waves S1 radiated from the antenna 202 are reflected by one of the reflecting elements 102 described above, and the antenna 202 receives the radio waves SR1 reflected by the one of the reflecting elements 102. Here, the order of step S500 and step S400 may be reversed.

[0083] 11, it is confirmed whether the radio wave SR1 received by the antenna 202 has a desired phase difference. The desired phase difference is a reference phase difference of the radio wave corresponding to an appropriately determined voltage applied between the patch electrode 108 and the common electrode 110. The phase difference of the radio wave SR1 is compared with the reference phase difference to determine whether the one reflecting element 102 described above is operating normally.

[0084] When checking the operation of a plurality of reflecting elements 102, steps S200 to S600 may be repeated. For example, when checking the operation of all reflecting elements 102 of the radio wave reflecting device 100, the stage 206 or the control unit 204 may be moved so that the control unit 204 scans the radio wave S1 inside the radio wave reflecting device 100, and radio waves may be repeatedly transmitted and received to adjacent reflecting elements 102.

[0085] To check the operation of one reflective element 102 by applying voltages V0 to Vn (n is a natural number) with different absolute values ​​between the patch electrode 108 and the common electrode 110 of the reflective element 102, steps S400 to S600 can be repeated.

[0086] For example, with the opening 208 superimposed on one reflecting element 102, a voltage V0 is applied between the patch electrodes 108 and the common electrode 110 of the plurality of reflecting elements 102, and the antenna 202 transmits and receives radio waves to determine whether one reflecting element 102 is operating normally. Here, the voltage V0 is a state in which no voltage is applied between the plurality of patch electrodes and the common electrode.

[0087] Next, a voltage V1 is applied between the patch electrodes 108 and the common electrodes 110 of the plurality of reflecting elements 102, and the antenna 202 transmits and receives radio waves to determine whether one of the reflecting elements 102 is operating normally. Here, the voltage V1 has an absolute value greater than that of the voltage V0.

[0088] As described above, the inspection method for the radio wave reflecting device 100 according to one embodiment of the present invention applies a desired voltage between the patch electrode 108 and the common electrode 110 of the reflecting element 102 of the radio wave reflecting device 100, and transmits and receives radio waves to and from the specific reflecting element 102, thereby making it possible to determine whether the specific reflecting element 102 is good or bad.

[0089] The above-described embodiments of the present invention may be combined as appropriate as long as they are not mutually inconsistent. Furthermore, even if a person skilled in the art appropriately adds or deletes components or modifies designs, or adds or omits processes or modifies conditions based on the embodiments, such combinations are included within the scope of the present invention as long as they include the gist of the present invention.

[0090] Even if there are other effects and advantages different from those brought about by the aspects of each of the above-mentioned embodiments, those that are clear from the description in this specification or that can be easily predicted by a person skilled in the art are naturally understood to be brought about by the present invention.

[0091] 100: radio wave reflecting device, 100a: radio wave reflecting device, 100b: radio wave reflecting device, 102: reflecting element, 102-1: reflecting element, 102-2: reflecting element, 102a: reflecting element, 102b: reflecting element, 104: dielectric substrate, 106: opposing substrate, 108: patch electrode, 108-1: patch electrode, 108-2: patch electrode, 110: common electrode, 112a: first alignment film, 112b: second alignment film, 114: liquid crystal layer, 116: liquid crystal molecules, 118: first wiring, 120: radio wave reflecting plate, 122: peripheral area, 124: first driving circuit, 126: terminal portion, 128: sealing material, 130: second 2 drive circuit, 132: second wiring, 134: switching element, 136: undercoat layer, 138: first gate electrode, 140: first gate insulating layer, 142: semiconductor layer, 144: first connection wiring, 146: second gate insulating layer, 148: second gate electrode, 150: first interlayer insulating layer, 152: second connection wiring, 154: second interlayer insulating layer, 156: planarization layer, 158: passivation layer, 200: inspection device, 202: antenna, 204: control unit, 204a: control unit, 204AB: second surface, 204AF: first surface, 206: stage, 208: opening, 210: radio wave absorbing unit

Claims

1. An inspection device for a radio wave reflecting device, comprising: an antenna for transmitting and receiving radio waves to a radio wave reflecting device having a plurality of reflecting elements each having a patch electrode and a common electrode; a stage on which the radio wave reflecting device is placed and which is positioned opposite the antenna; and a control unit which is positioned between the antenna and the stage, has an opening through which the radio waves pass, and uses the opening to control the irradiation area of ​​the radio waves in the radio wave reflecting device.

2. An inspection apparatus for a radio wave reflecting device as described in claim 1, wherein the control unit has a first surface facing the antenna and a second surface facing the stage, and a radio wave absorber is disposed on the first surface.

3. An inspection apparatus for a radio wave reflecting device as described in claim 1, wherein the control unit has a first surface facing the antenna and a second surface facing the stage, and a radio wave absorber is disposed on the second surface.

4. An inspection device for a radio wave reflecting device as described in claim 1, wherein the control unit has a first surface facing the antenna and a second surface facing the stage, at least one of the first surface and the second surface is convex toward the opposing antenna or stage, and a conductor is disposed on at least one of the surfaces.

5. An inspection device for a radio wave reflecting device as described in claim 4, wherein the control unit has, in a cross-sectional view, at least two ends in a direction intersecting the direction of propagation of the radio waves radiated from the antenna, and the length between the two ends is longer than the length of the opening in the direction of propagation of the radio waves.

6. An inspection device for a radio wave reflecting device according to claim 4, wherein the control unit reflects radio waves radiated from the antenna in a direction away from the opening.

7. An inspection device for a radio wave reflecting device according to claim 4, wherein the control unit reflects the radio waves reflected by the radio wave reflecting device in a direction away from the opening.

8. An inspection apparatus for a radio wave reflecting device according to claim 1, wherein the opening faces the patch electrode.

9. An inspection apparatus for a radio wave reflecting device as described in claim 1, wherein the opening is sized to expose a patch electrode of a first reflecting element of the plurality of reflecting elements, but not to expose a patch electrode of a second reflecting element of the plurality of reflecting elements adjacent to the first reflecting element.

10. An inspection apparatus for a radio wave reflecting device as described in claim 1, wherein a distance DR1 from said antenna to said control section is longer than a distance DR2 from said control section to said stage.

11. The distance DR1 from the antenna to the control unit satisfies the following formula 1: DR1 × tan (θ Ｈ / 2)<D1 (Formula 1) In the formula 1, the half-value angle of the radio wave radiated from the antenna is θ Ｈ The inspection apparatus for a radio wave reflecting device according to claim 10, wherein the width of the control portion is D1 [mm].

12. The distance DR3 from the antenna to the stage satisfies the following formula 2: DR3 × tan (θ Ｈ / 2) < D2 (Equation 2) In the above equation 2, the half-value angle of the radio wave radiated from the antenna is θ Ｈ The inspection apparatus for a radio wave reflecting device according to claim 10, wherein a width of the radio wave reflecting plate constituted by the plurality of reflecting elements is D2 [mm].

13. An inspection apparatus for a radio wave reflecting device according to claim 1, wherein the stage has a flat surface and is movable in a direction perpendicular to the direction in which the radio waves are emitted.

14. An inspection apparatus for a radio wave reflecting device as described in claim 1, wherein the control unit is movable in a direction perpendicular to the direction in which the radio waves are emitted.

15. The radio wave reflecting device inspection apparatus according to claim 1, wherein the antenna is a directional antenna.

16. A method for inspecting a radio wave reflecting device having a plurality of reflecting elements, the plurality of reflecting elements having a patch electrode and a common electrode, comprising: superimposing a first reflecting element of the plurality of reflecting elements on an opening through which radio waves radiated from the antenna pass, in a control section between an antenna and a stage facing the antenna and on which the radio wave reflecting device is placed; radiating radio waves from the antenna to the first reflecting element; receiving the radio waves reflected by the first reflecting element at the antenna; and judging the quality of the first reflecting element based on the phase difference of the received radio waves.

17. A method for inspecting a radio wave reflecting device as described in claim 16, wherein the opening is sized to expose a patch electrode of a first reflecting element of the plurality of reflecting elements, but not to expose a patch electrode of a second reflecting element of the plurality of reflecting elements adjacent to the first reflecting element.

18. A method for inspecting a radio wave reflecting device according to claim 16, further comprising applying a voltage V0 between said plurality of patch electrodes and said common electrode, said voltage V0 being a state in which no voltage is applied between said plurality of patch electrodes and said common electrode.

19. A method for inspecting a radio wave reflecting device as described in claim 18, comprising the steps of: applying a voltage V1 having an absolute value greater than voltage V0 between each of the plurality of patch electrodes and the common electrode; receiving radio waves reflected by the first reflecting element with the antenna; and judging whether the first reflecting element is good or bad based on an amount of phase change in the received radio waves.

20. A method for inspecting a radio wave reflecting device as described in claim 16, comprising: overlapping a second reflecting element adjacent to the first reflecting element among the plurality of reflecting elements with the opening; emitting radio waves from the antenna to the second reflecting element; receiving the radio waves reflected by the second reflecting element with the antenna; and determining whether the second reflecting element is good or bad based on the amount of phase change of the received radio waves.

Images