Radio wave reflecting device

Abstract

A radio wave reflection device according to one embodiment includes: a plurality of patch electrodes; a common electrode opposite to the plurality of patch electrodes; and a liquid crystal layer between the plurality of patch electrodes and the common electrode, the plurality of patch electrodes including a first patch electrode and a second patch electrode adjacent to the first patch electrode, a first distance between the first patch electrode and the common electrode being shorter than a second distance between the second patch electrode and the common electrode, the first distance is a distance from a first surface of the first patch electrode facing the common electrode to a surface of the common electrode facing the first patch electrode, and the second distance is a distance from a first surface of the second patch electrode facing the common electrode to a surface of the common electrode facing the second patch electrode.

Description

Technical Field

[0001] One embodiment of the present invention relates to a radio wave reflection device. Background Art

[0002] A phased array antenna device controls directivity in a state where the antenna is fixed by adjusting the amplitude and phase of a high-frequency signal to be applied to a plurality of antenna elements arranged in a planar shape, respectively. A phased array antenna device requires a phase shifter. A phased array antenna device using a phase shifter has been disclosed, in which the phase shifter utilizes a change in dielectric constant achieved based on the alignment state of liquid crystal (for example, refer to Patent Document 1).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2019-530387 Summary of the Invention

[0006] Even if the alignment state of the liquid crystal is changed to the maximum extent in the above-described radio wave reflection device, the controllable range (the range in which the traveling direction of the radio wave can be adjusted) has a limit and cannot correspond to all directions. Therefore, when it is desired to supply radio waves to an area that is out of the controllable range of the radio wave reflection device, it is necessary to pre-adjust the direction of the reflecting surface (working surface) of the radio wave reflection device so that the corresponding area falls within the controllable range of the radio wave reflection device. However, depending on the installation environment of the radio wave reflection device, it may be difficult to direct the reflecting surface of the radio wave reflection device in the desired direction.

[0007] One problem of one embodiment of the present invention is to provide a radio wave reflection device having directivity in an initial state.

[0008] The radio wave reflection device in one embodiment of the present invention includes: a plurality of patch electrodes; a common electrode facing the plurality of patch electrodes; and a liquid crystal layer between the plurality of patch electrodes and the common electrode. The plurality of patch electrodes include a first patch electrode and a second patch electrode adjacent to the first patch electrode. A first distance between the first patch electrode and the common electrode is shorter than a second distance between the second patch electrode and the common electrode. The first distance is the distance from a first surface of the first patch electrode facing the common electrode to the surface of the common electrode facing the first patch electrode, and the second distance is the distance from a first surface of the second patch electrode facing the common electrode to the surface of the common electrode facing the second patch electrode. Brief Description of the Drawings

[0009] Figure 1 It is a top view showing the structure of a radio wave reflection device according to one embodiment of the present invention.

[0010] Figure 2A It is a top view showing the structure of a reflection element in a radio wave reflection device according to an embodiment of the present invention.

[0011] Figure 2B It is a cross-sectional view showing the structure of a reflection element in a radio wave reflection device according to an embodiment of the present invention.

[0012] Figure 3A It is a diagram showing the operating state of a reflection element in a radio wave reflection device according to an embodiment of the present invention.

[0013] Figure 3B It is a diagram showing the operating state of a reflection element in a radio wave reflection device according to an embodiment of the present invention.

[0014] Figure 4 It is a cross-sectional view showing the structure of a reflection element in a radio wave reflection device according to an embodiment of the present invention.

[0015] Figure 5 It is a cross-sectional view showing the structure of a reflection element in a radio wave reflection device according to an embodiment of the present invention.

[0016] Figure 6 It is a schematic diagram for explaining the traveling direction of a reflected wave in a control state in a radio wave reflection device according to an embodiment of the present invention.

[0017] Figure 7 It is a cross-sectional view showing the structure of a reflection element in a radio wave reflection device according to an embodiment of the present invention.

[0018] Figure 8 It is a cross-sectional view showing the structure of a reflection element in a radio wave reflection device according to other embodiments of the present invention.

[0019] Figure 9 It is a cross-sectional view showing the structure of a reflection element in a radio wave reflection device according to other embodiments of the present invention.

[0020] Figure 10A It is a cross-sectional view showing the manufacturing method of a radio wave reflection device according to an embodiment of the present invention.

[0021] Figure 10B It is a cross-sectional view showing the manufacturing method of a radio wave reflection device according to an embodiment of the present invention.

[0022] Figure 10C It is a cross-sectional view showing the manufacturing method of a radio wave reflection device according to an embodiment of the present invention.

[0023] Figure 10DIt is a cross-sectional view of a method for manufacturing a radio wave reflection device according to an embodiment of the present invention.

[0024] Figure 10E It is a cross-sectional view of a method for manufacturing a radio wave reflection device according to an embodiment of the present invention.

[0025] Figure 11A It is a cross-sectional view of a method for manufacturing a radio wave reflection device according to an embodiment of the present invention.

[0026] Figure 11B It is a cross-sectional view of a method for manufacturing a radio wave reflection device according to an embodiment of the present invention.

[0027] Figure 11C It is a cross-sectional view of a method for manufacturing a radio wave reflection device according to an embodiment of the present invention.

[0028] Figure 11D It is a cross-sectional view of a method for manufacturing a radio wave reflection device according to an embodiment of the present invention.

[0029] Figure 11E It is a cross-sectional view of a method for manufacturing a radio wave reflection device according to an embodiment of the present invention.

[0030] Figure 11F It is a cross-sectional view of a method for manufacturing a radio wave reflection device according to an embodiment of the present invention.

[0031] Figure 11G It is a cross-sectional view of a method for manufacturing a radio wave reflection device according to an embodiment of the present invention.

[0032] Figure 11H It is a cross-sectional view of a method for manufacturing a radio wave reflection device according to an embodiment of the present invention.

[0033] Figure 12A It is a cross-sectional view of a method for manufacturing a radio wave reflection device according to an embodiment of the present invention.

[0034] Figure 12B It is a cross-sectional view of a method for manufacturing a radio wave reflection device according to an embodiment of the present invention.

[0035] Figure 12C It is a cross-sectional view of a method for manufacturing a radio wave reflection device according to an embodiment of the present invention.

[0036] Figure 12D It is a cross-sectional view of a method for manufacturing a radio wave reflection device according to an embodiment of the present invention.

[0037] Figure 13 It is a top view of a radio wave reflection device according to an embodiment of the present invention.

[0038] Figure 14 A cross-sectional view of a reflective element in a radio wave reflection device according to an embodiment of the present invention. Detailed implementation mode

[0039] Hereinafter, embodiments of the present invention will be described with reference to the drawings and the like. However, the present invention can be implemented in many different forms and is not limited to the description of the embodiments illustrated below. Regarding the drawings, in order to make the description clearer, the width, thickness, shape, etc. of each part are sometimes shown schematically compared with the actual form, but this is only an example and does not limit the interpretation of the present invention.

[0040] In this specification and each figure, sometimes the same reference numerals are assigned to elements that are the same as those described with respect to the figures that have already appeared, and the detailed description is appropriately omitted. In addition, for elements having the same function, for the convenience of description, sometimes letters such as "a" and "b" are added after the same reference numeral for distinction. However, when there is no need for special distinction and description, sometimes the same reference numerals are used for description. In addition, the words "first" and "second" attached to each element are convenient identifiers used to distinguish each element and do not have more meanings unless otherwise specified.

[0041] In this specification, when it is assumed that a certain component or region is "above (or below)" another component or region, unless otherwise specifically limited, it includes not only the case where it is directly above (or directly below) another component or region, but also the case where it is above (or below) another component or region, that is, it also includes the case where other constituent elements are included between it and another component or region above (or below).

[0042] In this specification, for expressions such as "α includes A, B, or C", "α includes any one of A, B, and C", and "α includes one selected from the group consisting of A, B, and C", unless otherwise specifically stated, the case where α includes multiple combinations of A to C is not excluded. In addition, these expressions do not exclude the case where α includes other elements.

[0043] <First Embodiment>

[0044] (Structure of the radio wave reflection device)

[0045] Figure 1 is a top view showing the structure of a radio wave reflection device 100 according to an embodiment of the present invention. The radio wave reflection device 100 of the present embodiment has a structure in which a plurality of electrode groups are arranged in parallel in a second direction (X direction or row direction) intersecting a first direction, and each of the electrode groups is composed of a plurality of patch electrodes 108 connected in series in the first direction (Y direction or column direction). InFigure 1 In this case, the first direction (the up-down direction facing the drawing) corresponds to the column direction, and the second direction (the left-right direction facing the drawing) corresponds to the row direction. In the present embodiment, an example of one-dimensional control in which the traveling direction of the reflected wave is changed in the second direction with the reflection axis VR as the rotation axis by using a plurality of patch electrodes 108 connected in the first direction will be described.

[0046] As Figure 1 shown, the radio wave reflection device 100 includes a reflector 120. The reflector 120 is composed of a plurality of reflection elements 102. The plurality of reflection elements 102 in the present embodiment are arranged in a matrix in the aforementioned first direction and second direction. The specific structure of the reflection element 102 will be described later. The reflection element 102 is arranged such that a plurality of patch electrodes 108 face the incident surface of the radio wave. The reflector 120 is a flat-structured body composed of a plurality of reflection elements 102. The traveling direction of the radio wave (reflected wave) reflected by the reflector 120 is controlled by the voltage applied to each patch electrode 108 and the distance between each different patch electrode 108 and the common electrode 110.

[0047] The radio wave reflection device 100 has a structure in which a plurality of reflection elements 102 are integrated on one dielectric substrate (dielectric layer) 104. As Figure 1 shown, the radio wave reflection device 100 has a structure in which a substrate 104 on which a plurality of patch electrodes 108 are arranged and a substrate 106 provided with a common electrode 110 facing the plurality of patch electrodes 108 are overlapped, and a liquid crystal layer (not shown) is provided between the two substrates.

[0048] The reflector 120 is formed in a region where the plurality of patch electrodes 108 and the common electrode 110 overlap. The substrate 104 and the substrate 106 are bonded using a sealing material 128 made of, for example, a photocurable resin material. Although not shown, the liquid crystal layer is provided in a region inside the sealing material 128.

[0049] In addition to the region facing the substrate 106, the substrate 104 also has a peripheral region 122 extending outward from the substrate 106. A first drive circuit 124 and a terminal portion 126 are provided in the peripheral region 122. The first drive circuit 124 outputs a control signal to each patch electrode 108. The terminal portion 126 is a region that functions as a connection portion to an external circuit (not shown), and is connected to, for example, a flexible printed circuit board although not shown. A signal for controlling the first drive circuit 124 is input to the terminal portion 126.

[0050] In the reflector 120, a plurality of patch electrodes 108 are connected to a first wiring 118 extending in a first direction. That is, each patch electrode 108 is interconnected via the first wiring 118. The reflector 120 has a structure in which a plurality of electrode groups are arranged in a second direction (row direction), and each of the electrode groups is composed of a plurality of patch electrodes 108 connected in the first direction (column direction) by the first wiring 118.

[0051] A plurality of first wirings 118 extend to a peripheral region 122 and are connected to a first drive circuit 124. The first drive circuit 124 outputs a control signal supplied to each patch electrode 108. Specifically, the first drive circuit 124 can output control signals of mutually different voltages to the plurality of first wirings 118 respectively. By making the control signals supplied to each first wiring 118 different (that is, making the voltages applied to each first wiring 118 different), in the reflector 120, for the plurality of patch electrodes 108 arranged in the first direction and the second direction, different control signals are supplied for each column (that is, for each electrode group composed of a plurality of patch electrodes 108 arranged in the first direction).

[0052] The radio wave reflection device 100 can control the traveling direction of the reflected wave of the radio wave incident on the reflector 120 by supplying different control signals to each electrode group composed of a plurality of patch electrodes 108 arranged in the first direction. That is, the radio wave reflection device 100 can change the reflection direction of the radio wave irradiated on the reflector 120 in the left - right direction (row direction) of the drawing with a reflection axis VR parallel to the first direction as the center.

[0053] (Structure of the reflection element)

[0054] Figure 2A It is a top view showing the structure of a reflection element group 10 of a reflection element 102 in a radio wave reflection device 100 according to an embodiment of the present invention. Figure 2B It is a cross - sectional view showing the structure of a reflection element 102 in a radio wave reflection device 100 according to an embodiment of the present invention. Specifically, Figure 2B It corresponds to a cross - sectional view obtained by cutting the reflection element group 10 of the reflection element 102 along A1 - A2 shown. Figure 2A as shown in

[0055] As Figure 2A and Figure 2B shown, the reflection element 102 includes a substrate 104, a substrate 106, a patch electrode 108, a common electrode 110, a liquid crystal layer 114, an alignment film 112a, and an alignment film 112b. It should be noted that in Figure 2A and Figure 2BThe patch electrode 108 marked in the figure will be described. However, unless otherwise specified, the description related to the patch electrode 108 is common to the patch electrode 108a, the patch electrode 108b, and the patch electrode 108c.

[0056] The patch electrode 108 is provided on the substrate 104. The patch electrode 108 of the substrate 104 is located on the first surface 104f opposite to the substrate 106. In the reflective element 102, the substrate 104 can be regarded as a dielectric layer having a predetermined dielectric constant. The patch electrode 108 preferably has a symmetric shape. However, depending on the structure such as the interconnection of the patch electrodes, it is not always the case. Figure 2A An example in which the patch electrode 108 is square in plan view is shown.

[0057] The common electrode 110 is provided on the substrate 106. The common electrode 110 is located on the first surface 106f of the substrate 106 opposite to the substrate 104. There is no particular limitation on the shape of the common electrode 110. The common electrode 110 of the present embodiment is provided over substantially the entire surface of the substrate 106 so as to face a plurality of patch electrodes 108.

[0058] There is no limitation on the materials constituting each of the patch electrodes 108 and the common electrode 110, and they are made of a conductive metal material, a metal oxide material, or the like. In addition, materials that reflect visible light can be used for each of the patch electrodes 108 and the common electrode 110. In addition, a metal material with a low resistivity can be used for the material forming the patch electrode 108. For example, a metal film such as aluminum (Al) or copper (Cu) can be used for the material forming the common electrode 110.

[0059] The alignment film 112a is provided so as to cover the patch electrode 108. The alignment film 112b is provided so as to cover the common electrode 110. The patch electrode 108 and the common electrode 110 are arranged to face each other with the liquid crystal layer 114 therebetween. The alignment film 112a is interposed between the patch electrode 108 and the liquid crystal layer 114, and the alignment film 112b is interposed between the common electrode 110 and the liquid crystal layer 114.

[0060] Although the liquid crystal layer 114 is not Figure 2A shown in Figure 2B and Figure 1 it is provided in the region surrounded by the sealing material 128 as shown in

[0061] The distance between the substrate 104 and the substrate 106 is 30 to 100 μm, for example, having a distance of 50 μm. A patch electrode 108, a common electrode 110, an alignment film 112a, and an alignment film 112b are provided between the substrate 104 and the substrate 106. Therefore, precisely speaking, the distance between the alignment film 112a and the alignment film 112b provided on the substrate 104 and the substrate 106 respectively becomes the thickness of the liquid crystal layer 114. It should be noted that although Figure 2B not shown in the figure, a spacer for maintaining a constant distance may also be provided between the substrate 104 and the substrate 106.

[0062] As Figure 1 shown, a first wiring 118 connected to the patch electrode 108 is provided on the substrate 104. In the present embodiment, the first wiring 118 is integrally formed with the patch electrode 108, but it is not limited to this example. That is, the first wiring 118 and the patch electrode 108 may also be formed as different elements. As Figure 1 shown, Figure 2A shown, the patch electrodes 108a to 108c are connected to other adjacent patch electrodes 108 via the first wiring 118.

[0063] A control signal for controlling the alignment of the liquid crystal molecules in the liquid crystal layer 114 is applied to the patch electrode 108 using the first wiring 118. The control signal is a signal of a DC voltage, or a polarity inversion signal in which a positive DC voltage and a negative DC voltage are alternately inverted. The common electrode 110 is applied with a voltage of ground (common) or an intermediate level of a polarity inversion signal. By applying a control signal to the patch electrode 108, the alignment state of the liquid crystal molecules contained in the liquid crystal layer 114 changes.

[0064] A liquid crystal material having dielectric anisotropy is used for the liquid crystal layer 114. For example, as the liquid crystal layer 114, nematic liquid crystal, smectic liquid crystal, cholesteric liquid crystal, or discotic liquid crystal can be used. The dielectric constant of the liquid crystal layer 114 having dielectric anisotropy changes according to the change in the alignment state of the liquid crystal molecules. The reflection element 102 can change the dielectric constant of the liquid crystal layer 114 by the control signal applied to the patch electrode 108, and thereby can cause a phase delay of the reflected wave when reflecting radio waves.

[0065] The wavelength band of the radio wave reflected by the reflection element 102 is the very high frequency (VHF) band, the ultra-high frequency (UHF) band, the super high frequency (SHF) band, the tremendously high frequency (THF), and the extra high frequency (EHF) band. The liquid crystal molecules of the liquid crystal layer 114 change their orientation in response to the control signal applied to the patch electrode 108, but hardly follow the frequency of the radio wave incident on the patch electrode 108. Therefore, the reflection element 102 can control the phase of the reflected radio wave without being affected by the radio wave.

[0066] Here, with reference to Figure 3A and Figure 3B the orientation state of the liquid crystal layer 114 when voltages are applied to the patch electrode 108 and the common electrode 110 of the reflection element 102 will be described.

[0067] Figure 3A It shows the state where no voltage is applied between the patch electrode 108 and the common electrode 110 (referred to as the "first state"). Figure 3A It shows the case where the alignment films 112a and 112b are horizontal alignment films. In the first state, the major axis of the liquid crystal molecules 114M is horizontally aligned with respect to the surfaces of the patch electrode 108 and the common electrode 110 through the alignment films 112a and 112b. Figure 3B It shows the state where a control signal (voltage signal) is applied to the patch electrode 108 (referred to as the "second state"). In the second state, the liquid crystal molecules 114M are affected by the electric field and the major axis is vertically aligned with respect to the surfaces of the patch electrode 108 and the common electrode 110. The angle at which the major axis of the liquid crystal molecules 114M is aligned can also be aligned in a direction intermediate between the horizontal direction and the vertical direction according to the magnitude of the control signal applied to the patch electrode 108 (the magnitude of the voltage between the opposing electrode and the patch electrode).

[0068] When the liquid crystal molecules 114M have positive dielectric anisotropy, the dielectric constant in the second state is larger than that in the first state. In addition, when the liquid crystal molecules 114M have negative dielectric anisotropy, the apparent dielectric constant in the second state is smaller than that in the first state. The liquid crystal layer 114 having dielectric anisotropy can also be regarded as a variable dielectric layer. The reflection element 102 can be controlled by using the dielectric anisotropy of the liquid crystal layer 114 so that the phase of the reflected wave is delayed (or not delayed).

[0069] Refer again to Figure 2A and Figure 2B, the thickness of the liquid crystal layer 114 and the distance between the patch electrode 108 and the common electrode 110 are described, and the control of the reflection element 102 is described.

[0070] The thickness of the liquid crystal layer 114 is different between adjacent patch electrodes 108 and the common electrode 110. Specifically, as Figure 2B shown, between adjacent patch electrodes 108a, patch electrode 108b and the common electrode 110, the thickness of the liquid crystal layer 114 is different. The thickness of the liquid crystal layer 114 is also different between adjacent patch electrodes 108b, patch electrode 108c and the common electrode 110.

[0071] In addition, the distance between adjacent patch electrodes 108 and the common electrode 110 is different. For example, as Figure 2B shown, the distance D1 between the patch electrode 108a and the common electrode 110 and the distance D2 between the adjacent patch electrode 108b and the common electrode 110 are different. Specifically, the distance D1 is shorter than the distance D2. In other words, the distance D2 is longer than the distance D1.

[0072] The distance D1 represents the distance from the surface 108a1 of the patch electrode 108a opposite to the common electrode 110 to the surface 110f1 of the common electrode 110 opposite to the patch electrode 108a. In addition, the distance D2 represents the distance from the surface 108b1 of the patch electrode 108b opposite to the common electrode 110 to the surface 110f1 of the common electrode 110 opposite to the patch electrode 108b.

[0073] In addition, as Figure 2B shown, the distance D2 and the distance D3 between the adjacent patch electrode 108c and the common electrode 110 are different. Specifically, the distance D2 is shorter than the distance D3. In other words, the distance D3 is longer than the distance D2.

[0074] The distance D3 represents the distance from the surface 108c1 of the patch electrode 108c opposite to the common electrode 110 to the surface 110f1 of the common electrode 110 opposite to the patch electrode 108a.

[0075] If the distances between the patch electrode 108 and the common electrode 110 are different, such as distance D1 to distance D3, the phase differences of the reflected waves generated by the respective reflection elements 102a to 102c are different. The phase difference caused by the distance between the patch electrode 108 and the common electrode 110 is taken as the initial phase difference. Since distance D1 is shorter than distance D2, the initial phase difference of the reflected wave generated by the reflection element 102a based on distance D1 is smaller than the initial phase difference of the reflected wave generated by the reflection element 102b based on distance D2. Since distance D2 is shorter than distance D3, the initial phase difference of the reflected wave generated by the reflection element 102b based on distance D2 is smaller than the initial phase difference of the reflected wave generated by the reflection element 102c based on distance D3. Additionally, when distances D1 to D3 are set as one cycle and changed, for example, the phase difference at the reflection element 102a of distance D1 is set to 0°, the phase difference at the reflection element 102b of distance D2 is set to 120°, and the phase difference at the reflection element 102c of distance D3 is set to 240° for distances D1 to D3.

[0076] When distances D1 to D3 are set as one cycle and the distance between the patch electrode 108 and the common electrode 110 is changed in multiple cycles, as Figure 4 shown, the reflection element 102a of distance D1 is arranged beside the reflection element 102c of distance D3. Figure 4 is a cross-sectional view showing the structure of the reflection element in the radio wave reflection device according to an embodiment of the present invention.

[0077] As Figure 4 shown, the distance between the patch electrode 108 and the common electrode 110 changes from the patch electrode 108a to the patch electrode 108c in distances D1 to D3, and further repeatedly changes from the patch electrode 108a to the patch electrode 108c in distances D1 to D3. As described above, at this time, the phase difference at the reflection element 102a of distance D1 is 0°, the phase difference at the reflection element 102b of distance D2 is 120°, the phase difference at the reflection element 102c of distance D3 is 240°, and the phase difference of the reflection element 102a of distance D1 located beside the reflection element 102c of distance D3 is 0° (360°).

[0078] In Figure 4 an example of the change using three different distances such as distances D1 to D3 is shown, but the number of different distances is not limited to three, and various different distance changes can be used. For example, as Figure 5 shown, four different distance changes can be used. Figure 5 is a cross-sectional view showing the structure of the reflection element in the radio wave reflection device according to an embodiment of the present invention.

[0079] As shown Figure 5 in the figure, the distance can be gradually changed from the shortest distance D1 to the longest distance D4 among four different distances. The distances D1 to D4 are set as one cycle, and the distance between the patch electrode 108 and the common electrode 110 is changed in multiple cycles. By changing the distance between the patch electrode 108 and the common electrode 110 in multiple cycles, the thickness of the liquid crystal layer 114 can also be periodically changed between each patch electrode 108 and the common electrode 110.

[0080] The phase differences of the reflected waves generated by the respective reflection elements 102a to 102d based on the distances D1 to D4 are also different from each other in the same way as the reflection elements 102a to 102c described above. The phase differences of the reflection elements 102a to 102c have the magnitude relationship as described above. In addition, the phase difference of the reflected wave generated by the reflection element 102d based on the distance D4 is larger than the phase difference of the reflected wave generated by the reflection element 102c based on the distance D3. At this time, the distances D1 to D4 are set such that the phase difference at the reflection element 102a is 0°, the phase difference at the reflection element 102b is 90°, the phase difference at the reflection element 102c is 180°, the phase difference at the reflection element 102d is 240°, and the phase difference of the reflection element 102a at the distance D1 next to the reflection element 102d at the distance D4 (not shown) is 0° (360°).

[0081] Here, a case where the initial phase difference of the reflected wave generated based on each reflection element 102 is set by changing the distance between the patch electrode 108 and the common electrode 110 will be described with reference to Figure 6 FIG. Figure 6 is a schematic diagram showing the traveling direction of the reflected wave in the control state in the radio wave reflection device according to an embodiment of the present invention.

[0082] Figure 6 Schematically shows a case where the traveling direction of the reflected wave is changed by the three reflection elements 102 with the distance between the patch electrode 108 and the common electrode 110 being the distances D1 to D3. The following is shown: When radio waves are incident on the reflection elements 102a to 102c with the same phase, since different control signals (V1≠V2≠V3) are applied to the reflection elements 102a to 102c, the phase difference of the reflected wave generated by the reflection element 102b is larger than that of the reflection element 102a, and the phase difference of the reflected wave generated by the reflection element 102c is larger than that of the reflection element 102b.

[0083] In addition, the following is shown: Since the distances between the patch electrodes 108 of the reflection elements 102a to 102c and the common electrode 110 are different distances D1 to D3, when radio waves are incident on the reflection elements 102a to 102c with the same phase, the initial phase differences of the reflected waves generated by the reflection elements 102a to 102c are different. Specifically, the following is shown: The phase difference of the reflected wave generated by the reflection element 102b based on the distance D2 is larger than the phase difference of the reflected wave generated by the reflection element 102a based on the distance D1; the phase difference of the reflected wave generated by the reflection element 102c based on the distance D3 is larger than the phase difference of the reflected wave generated by the reflection element 102b based on the distance D2.

[0084] As a result, the phases of the reflected wave R1 reflected by the reflection element 102a, the reflected wave R2 reflected by the reflection element 102b, and the reflected wave R3 reflected by the reflection element 102c are different. For example, in Figure 6 , the phase of the reflected wave R2 leads the phase of the reflected wave R1, and the phase of the reflected wave R3 leads the phase of the reflected wave R2. In addition, the phase difference between the reflected wave R1 reflected by the reflection element 102a and the reflected wave R2 reflected by the reflection element 102b, and the phase difference between the reflected wave R2 reflected by the reflection element 102b and the reflected wave R3 reflected by the reflection element 102c are the same. The reflected wave generated by the reflection element group 10 has an equiphase surface as shown in Figure 6 , and the traveling direction of the reflected wave changes to an inclined direction or a direction perpendicular to the equiphase surface. In addition, due to the initial phase difference of the reflected wave generated by the reflection element 102, the traveling direction of the reflected wave can also reach a range that cannot be achieved by applying a voltage to the reflection element 102.

[0085] The traveling direction of the reflected wave can be controlled by the periodic change in the distance between the patch electrode 108 and the common electrode 110. For example, as shown in Figure 1 , when changing the reflection direction of the reflected wave generated by the reflection element 102 in the left - right direction (X - direction) of the drawing with the reflection axis VR parallel to the first direction as the center, it is only necessary to periodically change the distance between the patch electrode 108 and the common electrode 110 in the left - right direction of the drawing. In addition, although the details will be described later, when changing in the up - down direction (Y - direction) of the drawing with the reflection axis HR parallel to the second direction as the center in addition to the reflection axis VR parallel to the first direction, it is only necessary to periodically change the distance between the patch electrode 108 and the common electrode 110 not only in the left - right direction of the drawing but also in the up - down direction of the drawing (refer to Figure 7 ).

[0086] The periodic change in the distance between the patch electrode 108 and the common electrode 110 can be adjusted by the insulating layer 116 provided between the patch electrode 108 and the substrate 104. For example, as Figure 2B shown, by providing the insulating layer 116 between the patch electrode 108a and the patch electrode 108b and the substrate 104, the periodic change in the distance between the patch electrode 108 and the common electrode 110 can be adjusted.

[0087] By providing the insulating layer 116 between the patch electrode 108a and the substrate 104, the patch electrode 108a is separated from the substrate 104, and the patch electrode 108a and the substrate 104 can be separated by a distance D5. In addition, by providing the insulating layer 116 between the patch electrode 108b and the substrate 104, the patch electrode 108b is separated from the substrate 104, and the distance between the patch electrode 108b and the substrate 104 can be separated by a distance D6. At this time, the thicknesses of the patch electrode 108a and the patch electrode 108b are equal or substantially equal, and the distance D5 can be longer than the distance D6. By making the distance D5 longer than the distance D6, the distance D1 can be shorter than the distance D2.

[0088] In addition, the same applies to the distances D2 and D3. As described above, the insulating layer 116 is provided between the patch electrode 108b and the common electrode 110, and the insulating layer 116 is not provided between the patch electrode 108c and the common electrode 110, so that the distance D2 can be made shorter than the distance D3. Or, as Figure 4 shown, the insulating layer 116 can also be provided between the patch electrode 108b and the patch electrode 108c and the substrate 104, so that the distance D6 between the patch electrode 108b and the substrate 104 and the distance D7 between the patch electrode 108c and the substrate 104 are different, and the distance D2 is adjusted to be shorter than the distance D3.

[0089] The distances D5 to D7 represent the distances between the substrate 104 and the respective patch electrodes 108 as described above. Specifically, the distance D5 is the distance from the surface 108a2 of the patch electrode 108a opposite to the surface 108a1 to the first surface 104f of the substrate 104 on which the patch electrode 108a is located. The distance D6 is the distance from the surface 108b2 of the patch electrode 108b opposite to the surface 108b1 to the first surface 104f of the substrate 104 on which the patch electrode 108b is located. The distance D7 is the distance from the surface 108c2 of the patch electrode 108c opposite to the surface 108c1 to the first surface 104f of the substrate 104 on which the patch electrode 108c is located.

[0090] (Modification 1 of the First Embodiment)

[0091] In Figure 2BIn [the figure], an example is shown in which an insulating layer 116 is provided between the patch electrode 108 and the substrate 104, and the distance between the patch electrode 108 and the common electrode 110 is periodically changed, but it is not limited to this example. For example, the distance between the patch electrode 108 and the common electrode 110 can be periodically changed by an insulating layer 117 provided between the common electrode 110 and the substrate 106.

[0092] The periodic change in the distance between the patch electrode 108 and the common electrode 110 can be adjusted by the insulating layer 117 provided between the common electrode 110 and the substrate 106. For example, within the region of the common electrode 110 that overlaps with each patch electrode 108, the thickness of the insulating layer 116 can be made different to adjust the periodic change in the distance between the patch electrode 108 and the common electrode 110. Figure 7 A cross-sectional view showing the structure of a reflection element in a radio wave reflection device according to an embodiment of the present invention, and an inset magnifying the region where the patch electrode 108 overlaps with the common electrode 110 are shown. For structures that are the same as or similar to the Figure 2B or Figure 5 structures described, the description may sometimes be omitted.

[0093] The insulating layer 117 is provided between the common electrode 110 and the substrate 106. Thereby, the distance between the common electrode 110 and the substrate 106 can be adjusted. In the region 119a where the patch electrode 108a overlaps with the common electrode 110, the insulating layer 117 is provided thicker than in the region 119b where the patch electrode 108b overlaps with the common electrode 110, and the common electrode 110 and the substrate 106 can be spaced apart by a distance D8. Through the interval of the distance D8 between the common electrode 110 and the substrate 106 in the region 119a, the distance between the patch electrode 108a and the common electrode 110 can be adjusted to a distance D1. At this time, the common electrode 110 has a uniform or substantially uniform thickness on the substrate 106.

[0094] In the region 119b where the patch electrode 108b overlaps with the common electrode 110, the insulating layer 117 is provided thicker than in the region where the patch electrode 108c overlaps with the common electrode 110, and the common electrode 110 and the substrate 106 can be spaced apart by a distance D9. At this time, as Figure 7 shown, in the region where the patch electrode 108c overlaps with the common electrode 110, the insulating layer 117 may not be provided between the common electrode 110 and the substrate 106. Through the interval of the distance D9 between the common electrode 110 and the substrate 106 in the region 119b, the patch electrode 108b and the common electrode 110 can be spaced apart by a distance D2. Through the interval of the distance D9 between the common electrode 110 and the substrate 106 in the region 119b, the distance between the patch electrode 108b and the common electrode 110 can be adjusted to a distance D2.

[0095] In the region where the patch electrode 108c overlaps with the common electrode 110, the insulating layer 117 may not be provided in the region where the patch electrode 108b overlaps with the common electrode 110, and the distance between the patch electrode 108b and the common electrode 110 may be set to the distance D3.

[0096] In addition, as described above, in the region 119c where the patch electrode 108c overlaps with the common electrode 110, as Figure 8 shown, the insulating layer 117 may also be provided thinner than in the region where the patch electrode 108b overlaps with the common electrode 110, so that the common electrode 110 is separated from the substrate 106 by a distance D10. Through the interval of the distance D9 between the common electrode 110 and the substrate 106 in the region where the patch electrode 108c overlaps with the common electrode 110, the distance between the patch electrode 108c and the common electrode 110 can be adjusted to the distance D3.

[0097] The distances D8 to D10 represent, as described above, the distances between the common electrodes overlapping with the patch electrodes 108a to 108d and the substrate 106, respectively. Specifically, the distance D8 represents the distance between the surface 110f2 of the common electrode 110 facing the first surface 104f of the substrate 104 and the first surface 106f of the substrate 106 in the region 119a where the patch electrode 108a overlaps with the common electrode 110. The distance D9 represents the distance between the surface 110f2 of the common electrode 110 facing the first surface 104f of the substrate 104 and the first surface 106f of the substrate 106 in the region 119b where the patch electrode 108b overlaps with the common electrode 110. The distance D10 represents the distance between the surface 110f2 of the common electrode 110 facing the first surface 104f of the substrate 104 and the first surface 106f of the substrate 106 in the region 119c where the patch electrode 108c overlaps with the common electrode 110.

[0098] By the different distances D8 to D10, the distances D1 to D3 are adjusted. As described above, with the distances D1 to D3 set as one cycle, the distance between the patch electrode 108 and the common electrode 110 changes in multiple cycles.

[0099] (Modification Example 2 of the First Embodiment)

[0100] In Figure 2BIn the figure, an example is shown in which an insulating layer 116 is provided between the patch electrode 108 and the substrate 104, and the distance between the patch electrode 108 and the common electrode 110 is periodically changed, but it is not limited to this example. For example, by providing an insulating layer 116 provided between the common electrode 110 and the substrate 106 and an insulating layer 117 provided between the common electrode 110 and the substrate 106, the distance between the patch electrode 108 and the common electrode 110 can be periodically changed.

[0101] Figure 9 A cross-sectional view showing the structure of a reflection element in a radio wave reflection device according to an embodiment of the present invention is shown. For structures that are the same as or similar to the structures described using Figure 2B or Figure 5 the description may sometimes be omitted.

[0102] As Figure 9 shown, the distances D1 to D3 can be adjusted by the insulating layer 116 and the insulating layer 117.

[0103] As described above, in the present embodiment, a radio wave reflection device 100 can be provided. By periodically changing the distance between the patch electrode 108 and the common electrode 110, an initial phase difference of the reflected wave can be set. Moreover, by controlling the voltage applied to the patch electrode 108 and the common electrode 110, the dielectric constant of the liquid crystal layer 114 between the patch electrode 108 and the common electrode 110 can be changed, and the range of the reflection direction of the reflected wave that cannot be achieved only by applying a voltage to the patch electrode 108 and the common electrode 110 can be filled.

[0104] (Manufacturing method 1 of the radio wave reflection device 100)

[0105] Figures 10A to 10E This is a cross-sectional view showing a manufacturing method of a reflection element 102 used in the radio wave reflection device 100 shown in Figure 2B the first embodiment of the present invention.

[0106] First, as Figure 10A shown, a contact hole 135 capable of being electrically connected to the switching element 134 is formed on the substrate 104 on which the switching element 134, the insulating layer 154, and the insulating layer 156 are formed.

[0107] Next, as Figure 10B shown, an organic photosensitive insulating film 116r is coated on the switching element 134, the insulating layer 154, and the insulating layer 156 and exposed to form the insulating layer 116. At this time, as Figure 10BAs shown, the exposure conditions are set to match the size of the initial phase difference. For example, in the region of the reflective element 102a where the initial phase difference is set to be small, the insulating layer 116 is exposed in a relatively thick manner; in the region of the reflective element 102b where the initial phase difference is set to be larger than the reflective element 102a and smaller than the reflective element 102c, the insulating layer 116hf is half-tone exposed. In addition, in the region of the reflective element 102c where the initial phase difference is set to be larger than the reflective element 102a and the reflective element 102b, the insulating layer 116hf is exposed in a relatively thick manner. In addition, in the region of the reflective element 102c where the initial phase difference is set to be larger than the reflective element 102a and the reflective element 102b, the insulating layer 116 is exposed in a relatively thick manner without forming the insulating layer 116. The insulating layer 116 may be a single-layer structure or a laminated structure. When the insulating layer 116 is set to be thick, the laminated structure may be used for the insulating layer 116.

[0108] Then, if Figure 10C As shown, the insulating layer 116 is developed and sintered.

[0109] Then, if Figure 10D As shown in FIG. 1 , a metal layer including a metal material constituting the patch electrode 108 is formed on the insulating layer 116 and the insulating layer 156 , and then the metal layer is etched to form the patch electrode 108 .

[0110] Finally, if Figure 10E As shown, the alignment film 112a is formed in a manner covering the patch electrode 108 and the insulating layer 116, and is attached to the substrate 106 formed with the common electrode 110. After that, liquid crystal is injected between the substrate 104 and the substrate 106 to form a liquid crystal layer 114. According to the above, the Figure 2B A reflecting element 102 is used in the radio wave reflecting device 100 shown.

[0111] (Method 2 for manufacturing radio wave reflection device 100)

[0112] Figures 11A to 11H This is a first embodiment of the present invention. Figure 2B 2 is a cross-sectional view of a method for manufacturing the reflection element 102 used in the radio wave reflection device 100. The description of the same or similar steps and structures as those in the method for manufacturing the reflection element 102 used in the radio wave reflection device 100 described above may be omitted.

[0113] First, if Figure 11A and Figure 11B As shown, a resist film 168res is coated on a substrate 104 on which a switch element 134 is formed, an insulating layer 154 is formed on the switch element 134, and an insulating layer 156 is formed on the insulating layer 154, and exposure is performed under conditions that match the thickness of the resist film 168 to be left for the reflective elements 102 with different initial phase differences. For example, Figure 11BAs shown, in the region of the reflection element 102a, exposure is performed in such a way as to form more resist films 168. In the region of the reflection element 102b, halftone exposure is performed in such a way that the resist film 168hf is formed thinner than the resist film 168 in the region of the reflection element 102a. In the region of the reflection element 102c, exposure is performed or not performed in such a way as not to form the resist film 168.

[0114] Next, as Figure 11C shown, the resist film 168 is developed and then sintered.

[0115] Next, as Figure 11D shown, the resist film 168 and the insulating layer 156 are dry-etched to form the insulating layer 156. In the portion where the film thickness of the resist film 168 formed on the insulating layer 156 is small, the resist film 168 is lost at an early stage as the dry etching progresses, and the etching of the insulating layer 156 progresses. In the portion where the film thickness is large, the resist film 168 is lost later, and the etching of the insulating layer 156 progresses. At Figure 11D the time point shown, in the portion where the resist film 168 has been lost, the film thickness of the insulating layer 156 becomes smaller; in the portion where the resist film 168 still remains, the insulating layer 156 is not etched. Further progressing the etching, as Figure 11D shown, all of the resist film 168 can be removed, or a part of the resist film 168 can remain and be used for forming the layer difference in the reflection element 102a portion. Here, Figure 2B the insulating layers of the reflection element 102a and the reflection element 102b shown can be formed to include the insulating layer 156 as Figure 11D shown.

[0116] Next, for the pattern formation of the contact hole 135, as Figure 11E shown, a resist film 160 is coated on the insulating layer 156, and exposure, development, and sintering are performed. As described above, the patch electrode 108 and the switching element 134 are electrically connected via the contact hole 135.

[0117] Next, as Figure 11F shown, the insulating layer 156 exposed by the pattern formation of the contact hole 135 is dry-etched and ashed to remove the resist film 160.

[0118] Next, as Figure 11G shown, the patch electrode 108 is formed.

[0119] Finally, the substrate 104 and the substrate 106 are bonded together. According to the above, the reflection element 102 used in the radio wave reflection device 100 shown in Figure 2B is completed.

[0120] (Manufacturing method 3 of the radio wave reflection device 100)

[0121] Figures 12A to 12D It is a cross-sectional view showing a manufacturing method of the reflection element 102 in which the distance between the patch electrode 108 and the common electrode 110 is adjusted by using the insulating layer 117 between the common electrode 110 and the substrate 106. For the processes and structures that are the same as or similar to the manufacturing method of the reflection element 102 used in the above radio wave reflection device 100, the description may sometimes be omitted.

[0122] First, a region for forming the reflection element 102c with a large initial phase difference is patterned. A resist film 161 is coated on the substrate 106, and exposure, development, and sintering are performed. As Figure 12A shown, the substrate 106 is etched. In Figure 12A , the substrate 106 in the region for forming the reflection element 102c is etched, but the region of the substrate 106 in the region for forming the reflection element 102b may also be patterned and etched. At this time, the substrate 106 may be etched such that the depth of the recess formed in the reflection element 102b is shallower than the depth of the recess formed in the reflection element 102c.

[0123] In Figure 12A , an example of forming a recess in the substrate 106 to obtain the distance D3 between the patch electrode 108c of the reflection element 102c and the common electrode 110 is shown. For a structure in which the distance between the patch electrode 108 and the common electrode 110 is different, it is not limited to the formation of the above recess, and the distance between the patch electrode 108 and the common electrode 110 may also be made different by forming an insulating layer 117 of an organic film or an inorganic film with different film thicknesses on the substrate 106. For example, as Figure 5 shown, the substrate 106 is not etched, the insulating layer 117 of the reflection element 102a and the reflection element 102b is formed on the substrate 106, and the insulating layer 117 is not formed in the region for forming the reflection element 102c. At this time, since the distance D1 is shorter than the distance D2, the thickness of the insulating layer 117 of the reflection element 102a may be formed to be thicker than the thickness of the insulating layer 117 of the reflection element 102b. In addition, the insulating layer 117 may be a single-layer structure or a laminated structure. When the insulating layer 117 is set to be thick, a laminated structure may be used for the insulating layer 117, or a combination of an organic film and an inorganic film may be used.

[0124] Next, the resist film 161 is peeled off, and the insulating layer 117 is patterned on the substrate 106 and sintered. In Figure 12BIn this case, the region on the substrate 106 where the reflection element 102a is formed is patterned and sintered for the insulating layer 117. At this time, the region of the reflection element 102b having an intermediate length between the patch electrode 108 and the common electrode 110 among the reflection elements 102a to 102c can be used as a reference to appropriately determine the depth of the recess in the region where the reflection element 102c is formed and the thickness of the insulating layer 117 in the region where the reflection element 102a is formed.

[0125] Next, a common electrode 110 is formed on the insulating layer 117 and the substrate 106.

[0126] Finally, the substrate 104 and the substrate 106 are bonded together. According to the above, the reflection element 102 that adjusts the distance between the patch electrode 108 and the common electrode 110 by using the insulating layer 117 between the common electrode 110 and the substrate 106 and is used in the radio wave reflection device 100 is completed.

[0127] <Second Embodiment>

[0128] In the first embodiment, an example of one-dimensional control for changing the traveling direction of the reflected wave in the second direction with the reflection axis VR as the rotation axis is described. In this embodiment, an example of two-dimensional control for also changing the traveling direction of the reflected wave in the first direction with the reflection axis HR as the rotation axis is described. Elements having the same functions as those in the first embodiment are denoted by the same reference numerals, and repeated descriptions are omitted.

[0129] Figure 13 It is a top view showing the structure of a radio wave reflection device 200 according to an embodiment of the present invention. The radio wave reflection device 200 of this embodiment has, in addition to a plurality of first wirings 118 extending in the first direction (column direction or Y direction) and arranged in the second direction, a plurality of second wirings 132 extending in the second direction (row direction or X direction) and arranged in the first direction. The plurality of first wirings 118 and the plurality of second wirings 132 cross each other with an insulating layer (not shown) therebetween. The plurality of first wirings 118 are connected to a first drive circuit 124 that outputs a control signal. The plurality of second wirings 132 are connected to a second drive circuit 130 that outputs a scan signal.

[0130] As Figure 13 shown in the enlarged view, each reflection element 202 includes a switching element 134. In this embodiment, the switching element 134 is a transistor. However, it is not limited to this example, and the switching element 134 can be any element as long as it has a function as a switch. It should be noted that in the enlarged view, a reflection element 202 including the patch electrode 108a is illustrated, but the reflection element 202 including the patch electrode 108b or the patch electrode 108c also has the same structure.

[0131] The switching element 134 is connected to the first wiring 118 and the second wiring 132. Specifically, the first wiring 118 is connected to the source of the transistor that is the switching element 134, and the second wiring 132 is connected to the gate. The switching function of the switching element 134 is controlled by a scan signal supplied to the second wiring 132. When the switching element 134 is in the on state, the patch electrode 108 is electrically connected to the first wiring 118, and a control signal is supplied to the patch electrode 108. With such a structure, it is possible to select, row by row, a plurality of patch electrodes 108 arranged in the second direction and supply control signals of different voltages to each row.

[0132] Figure 14 It is a cross-sectional view showing the structure of the reflection element 202 in the radio wave reflection device 200 according to another embodiment of the present invention. The switching element 134 includes 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. A bottom coating 136 is provided between the first gate electrode 138 and the dielectric substrate 104.

[0133] The first wiring 118 and the first connection wiring 144 are provided between the first gate insulating layer 140 and the second gate insulating layer 146. The first wiring 118 and the first connection wiring are provided in contact with the semiconductor layer 142. Specifically, the first wiring 118 is connected to the source side of the semiconductor layer 142, and the first connection wiring 144 is connected to the drain side of the semiconductor layer 142. However, the positional relationship between the source and the drain may be reversed depending on the voltage applied between the source and the drain of the transistor.

[0134] The switching element 134 is covered with the first interlayer insulating layer 150. The second wiring 132 is provided on the first interlayer insulating layer 150. The second wiring 132 is connected to the second gate electrode 148 via a contact hole formed in the first interlayer insulating layer 150. It should be noted that although not shown, the first gate electrode 138 and the second gate electrode 148 are electrically connected to each other in a region where they do not overlap with the semiconductor layer 142. On the first interlayer insulating layer 150, a second connection wiring 152 is provided using the same conductive layer as the second wiring 132. The second connection wiring 152 is connected to the first connection wiring 144 via a contact hole formed in the first interlayer insulating layer 150.

[0135] The second wiring 132 and the second connection wiring 152 are covered with an insulating layer 154. On the insulating layer 154, a planarization layer 156 (insulating layer 156) is provided so as to fill the level difference formed by the switching element 134. By providing the planarization layer 156, the chip electrode 108 can be formed without being affected by the arrangement of the switching element 134. A passivation layer 158 is provided on the planarization layer 156. The chip electrode 108 is provided on the passivation layer 158. The chip electrode 108 is connected to the second connection wiring 152 via a contact hole penetrating the passivation layer 158, the planarization layer 156, and the insulating layer 154. An alignment film 112a is provided on the chip electrode 108.

[0136] On the substrate 106, similar to the first embodiment Figure 2B a common electrode 110 and an alignment film 112b are provided in the same manner. The surface of the substrate 106 on which the common electrode 110 is provided is arranged to face the surface of the dielectric substrate 104 on which the chip electrode 108 is provided. A liquid crystal layer 114 is provided between the alignment film 112a and the alignment film 112b.

[0137] In Figure 14 the structure shown, the undercoat layer 136 is formed of, for example, a silicon oxide film. The first gate insulating layer 140 and the second gate insulating layer 146 are formed of, for example, a silicon oxide film or a stacked structure of a silicon oxide film and a silicon nitride film. The semiconductor layer is formed of, for example, a silicon semiconductor such as amorphous silicon or polycrystalline silicon, or an oxide semiconductor containing metal oxides such as indium oxide, zinc oxide, and gallium oxide. The first gate electrode 138 and the second gate electrode 148 are formed of, for example, 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 of a metal material such as titanium (Ti), aluminum (Al), or molybdenum (Mo). For example, each wiring may also be composed of a stacked structure of titanium (Ti) / aluminum (Al) / titanium (Ti) or molybdenum (Mo) / aluminum (Al) / molybdenum (Mo). The planarization layer 156 is formed of a resin material such as an acrylic resin or polyimide. The passivation layer 158 is formed of, for example, a silicon nitride film or the like. The chip electrode 108 and the common electrode 110 are formed of a metal film such as aluminum (Al) or copper (Cu), or a transparent conductive film such as indium tin oxide (ITO).

[0138] As Figure 8 shown, the second wiring 132 is connected to the gate of the transistor serving as the switching element 134, the first wiring 118 is connected to one of the source and the drain of the transistor, and the chip electrode 108 is connected to the other of the source and the drain. Thereby, a specified chip electrode can be selected from among a plurality of chip electrodes 108 arranged in a matrix to supply a control signal.

[0139] Thus, the radio wave reflection device 200 of the present embodiment can control the voltage applied to the patch electrode 108 for each reflection element 202. Therefore, not only can the applied voltage be made different between the patch electrodes 108 adjacent in the second direction, but also the applied voltage can be made different between the patch electrodes 108 adjacent in the first direction. That is, the radio wave reflection device 200 of the present embodiment has, in addition to the function of controlling the traveling direction of the reflected wave in the second direction centered on the reflection axis VR, the function of controlling the traveling direction of the reflected wave in the first direction centered on the reflection axis HR.

[0140] In addition, the radio wave reflection device 200 of the present embodiment makes the areas of the patch electrodes 108 adjacent to each other in the first direction different, so that even in the initial state, the phases of the reflected waves in the respective reflection elements 202 including the patch electrodes 108a to 108c can be made different. That is, the radio wave reflection device 200 of the present embodiment, like the radio wave reflection device 100 of the first embodiment, is set in the initial state such that the traveling direction of the reflected wave with respect to the incident wave is inclined in the first direction (column direction) in advance. Therefore, in the present embodiment, it is possible to change the traveling direction of the reflected wave inclined in the first direction in the initial state further in the first direction or the second direction by voltage control.

[0141] For example, in Figure 13 the example, since the reflected wave is set to face the first direction in advance in the initial state, by performing voltage control, the traveling direction of the reflected wave can be further changed in the first direction from the preset direction. By performing such control, the radio wave reflection device 200 can transmit radio waves to an area where radio waves cannot be transmitted only by voltage control.

[0142] The structures of the above-described embodiments (including modified examples) exemplified as one embodiment of the present invention can be appropriately combined as long as they do not contradict each other. In addition, a solution obtained by appropriately adding, deleting, or changing the design of constituent elements, or a solution obtained by adding, omitting, or changing conditions of a process based on the structures of the embodiments disclosed in the present specification and the drawings is also included in the scope of the present invention as long as it has the gist of the present invention.

[0143] Even for other effects different from those brought about by the forms of the embodiments disclosed in the present specification, effects that are clearly obtained from the description of the present specification or that can be easily predicted by those skilled in the art are of course understood to be effects brought about by the present invention.

[0144] Description of Reference Numerals

[0145] 10: Reflective element group, 20: Reflective element group, 100: Radio wave reflection device, 100a: Radio wave reflection device, 102: Reflective element, 102a: Reflective element, 102b: Reflective element, 102c: Reflective element, 102d: Reflective element, 104: Dielectric substrate, 104: Substrate, 104: Dielectric substrate (dielectric layer), 104f: First surface, 106: Substrate, 106f: First surface, 108: Patch electrode, 108a: Patch electrode, 108a1: Surface, 108a2: Surface, 108b: Patch electrode, 108b1: Surface, 108b2: Surface, 108c: Patch electrode, 108c1: Surface, 108c2: Surface, 110: Common electrode, 110f1: Surface, 110f2: Surface, 112a: Alignment film, 112b: Alignment film, 114: Liquid crystal layer, 114M: Liquid crystal molecules, 116: Insulating layer, 116hf: Insulating layer, 117: Insulating layer, 118: First wiring, 119a: Region, 119b: Region, 119c: Region, 120: Reflector, 122: Peripheral region, 124: First drive circuit, 126: Terminal portion, 128: Sealing material, 130: Second drive circuit, 132: Second wiring, 134: Switching element, 135: Contact hole, 136: Undercoat, 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: Insulating layer, 156: Planarization layer, 156: Insulating layer, 158: Passivation layer, 160: Resist film, 161: Resist film, 116r: Organic photosensitive insulating film, 168: Resist film, 168res: Resist film, 168hf: Resist film, 200: Radio wave reflection device, 202: Reflective element.

Claims

1. A radio wave reflection device, characterized in that, Comprising: Multiple patch electrodes; A common electrode opposite to the multiple patch electrodes; And A liquid crystal layer between the multiple patch electrodes and the common electrode, The multiple patch electrodes include a first patch electrode and a second patch electrode adjacent to the first patch electrode, A first distance between the first patch electrode and the common electrode is shorter than a second distance between the second patch electrode and the common electrode, The first distance is the distance from a first surface of the first patch electrode opposite to the common electrode to the surface of the common electrode opposite to the first patch electrode, The second distance is the distance from a first surface of the second patch electrode opposite to the common electrode to the surface of the common electrode opposite to the second patch electrode.

2. The radio wave reflection device according to claim 1, characterized in that The multiple patch electrodes further include a third patch electrode adjacent to the second patch electrode, A third distance between the third patch electrode and the common electrode is longer than the second distance, The third distance is the distance from a first surface of the third patch electrode opposite to the common electrode to the surface of the common electrode opposite to the third patch electrode.

3. The radio wave reflection device according to claim 2, characterized in that The phase difference between the reflected wave generated based on the first reflection element including the first patch electrode and the reflected wave generated based on the second reflection element including the second patch electrode, and the phase difference between the reflected wave generated based on the second reflection element and the reflected wave generated based on the third reflection element including the third patch electrode are the same.

4. The radio wave reflection device according to claim 1, characterized in that The multiple patch electrodes are located above a first surface of a first substrate, A fourth distance between the first patch electrode and the first substrate is longer than a fifth distance between the second patch electrode and the first substrate, The fourth distance is the distance from a second surface of the first patch electrode opposite to the first surface to the first surface of the first substrate, The fifth distance is the distance from a second surface of the second patch electrode opposite to the first surface to the first surface of the first substrate.

5. The radio wave reflection device according to claim 4, characterized in that The multiple patch electrodes further include a third patch electrode adjacent to the second patch electrode, The third patch electrode has a first surface opposite to the common electrode, A sixth distance between the third patch electrode and the first substrate is shorter than the fifth distance, The sixth distance is the distance from a second surface of the third patch electrode opposite to the first surface to the first surface of the first substrate.

6. The radio wave reflection device according to claim 1, characterized in that The multiple patch electrodes are located above a first surface of a first substrate, The common electrode is located above a first surface of a second substrate opposite to the first substrate, The distance between the surface of the common electrode facing the first surface of the second substrate and the first surface of the second substrate is different in the region where the first patch electrode overlaps with the common electrode and the region where the first patch electrode overlaps with the second patch electrode.

7. The radio wave reflection device according to claim 6, wherein the plurality of patch electrodes further includes a third patch electrode adjacent to the second patch electrode, the distance between the surface of the common electrode facing the first surface of the second substrate and the first surface of the second substrate is different in the region where the first patch electrode overlaps with the common electrode, the region where the second patch electrode overlaps with the common electrode, and the region where the third patch electrode overlaps with the common electrode.

8. The radio wave reflection device according to claim 4, wherein the common electrode is located on the first surface of the second substrate opposite to the first substrate, the distance between the surface of the common electrode facing the first surface of the second substrate and the first surface of the second substrate is different in the region where the first patch electrode overlaps with the common electrode and the region where the second patch electrode overlaps with the common electrode.

9. The radio wave reflection device according to claim 8, wherein the plurality of patch electrodes further includes a third patch electrode adjacent to the second patch electrode, the distance between the surface of the common electrode facing the first surface of the second substrate and the first surface of the second substrate is different in the region where the first patch electrode overlaps with the common electrode, the region where the second patch electrode overlaps with the common electrode, and the region where the third patch electrode overlaps with the common electrode.

10. The radio wave reflection device according to claim 1, wherein the plurality of patch electrodes are arranged in a matrix, the plurality of patch electrodes are connected in the arrangement direction of columns.

11. The radio wave reflection device according to claim 1, wherein the plurality of patch electrodes are located on the first surface of the first substrate, the radio wave reflection device further has a transistor electrically connected to the plurality of patch electrodes, the transistor is provided on the first substrate.

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