Driving method of radio wave reflecting device

Abstract

To provide a method for driving a radio wave reflection device with a high phase difference.SOLUTION: A method for driving a radio wave reflection device is a method for driving a radio wave reflection device that has a plurality of reflection elements arranged in a row direction and a column direction, and controls an amount of a change in a phase of a reflection wave by a voltage applied to the plurality of reflection elements, and the method includes: dividing the arrangement of the plurality of reflection elements into a first area for controlling the amount of the change in the phase of the plurality of reflection elements arranged in the column direction for every column, and a second area for controlling the amount of the change in the phase of the plurality of reflection elements arranged in the column direction for every two adjacent columns; and simultaneously driving the plurality of reflection elements belonging to the first area and the plurality of reflection elements belonging to the second area.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a method for driving a radio wave reflecting device that can control the traveling direction of reflected radio waves. [Background technology]

[0002] A phased array antenna device controls the directivity of a fixed antenna by adjusting the amplitude and phase of a high-frequency signal applied to each of a plurality of antenna elements arranged in a plane. Phased array antenna devices require a phase shifter. A phased array antenna device using a phase shifter that utilizes a change in the dielectric constant due to the orientation state of liquid crystals has been disclosed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-103201 Summary of the Invention [Problem to be solved by the invention]

[0004] A radio wave reflecting device that uses a radio wave reflector that can control the reflection direction using liquid crystal, such as a phased array antenna device, needs to have a wide variable range of the reflection phase to control the reflection direction in any direction, but there is a problem in that the variable range of the reflection phase is narrow.

[0005] In view of such problems, one object of one embodiment of the present invention is to provide a driving method that widens the variable range of the reflection phase of a radio wave reflecting device. [Means for solving the problem]

[0006] A method for driving a radio wave reflection device according to one embodiment of the present invention is a method for driving a radio wave reflection device having a plurality of reflection elements arranged in row and column directions, and controlling the amount of phase change of the reflected wave by a voltage applied to the plurality of reflection elements, wherein the arrangement of the plurality of reflection elements is divided into a first region in which the amount of phase change of the plurality of reflection elements arranged in the column direction is controlled for each row, and a second region in which the amount of phase change of the plurality of reflection elements arranged in the column direction is controlled for each two adjacent rows, and the plurality of reflection elements belonging to the first region and the second region are driven simultaneously. [Brief explanation of the drawings]

[0007] [Figure 1] 1A shows a reflection element used in a radio wave reflection device according to one embodiment of the present invention, in which (A) is a plan view thereof and (B) shows a cross-sectional structure taken along line A1-A2 shown in the plan view. [Figure 2] 1 shows two states in which a reflecting element used in a radio wave reflecting device according to one embodiment of the present invention operates, where (A) shows a state in which no voltage is applied between the patch electrode and the common electrode, and (B) shows a state in which a voltage is applied between the patch electrode and the common electrode. [Figure 3] 1 shows the configuration of a radio wave reflecting device according to one embodiment of the present invention. [Figure 4] 3A and 3B are diagrams illustrating how the propagation direction of a reflected wave is changed by a radio wave reflecting device according to an embodiment of the present invention. [Figure 5] 1 shows the configuration of a radio wave reflecting device according to one embodiment of the present invention. [Figure 6] An example of the addresses of the reflecting elements of the radio wave reflecting devices shown in FIGS. 3 and 5 is shown below. [Figure 7] 10A and 10B are diagrams illustrating voltages applied to a plurality of reflecting elements in a method for driving a radio wave reflecting device according to an embodiment of the present invention. [Figure 8] 10A and 10B are diagrams illustrating voltages applied to a plurality of reflecting elements in a method for driving a radio wave reflecting device according to an embodiment of the present invention. [Figure 9] 10A and 10B are diagrams illustrating voltages applied to a plurality of reflecting elements in a method for driving a radio wave reflecting device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0008] 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 embodiments exemplified below. For clarity of explanation, the drawings may show the width, thickness, shape, etc. of each part schematically compared to the actual form, but these are merely examples and do not 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.

[0009] In this specification, when a component or region is described 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.

[0010] 1. Reflective element 1(A) and (B) show a reflecting element 102 used in a radio wave reflecting device 100 according to one embodiment of the present invention. Fig. 1(A) shows a plan view of the reflecting element 102 as seen from above (the side where radio waves are incident), and Fig. 1(B) shows a cross-sectional view taken along line A1-A2 shown in the plan view.

[0011] 1(A) and 1(B), the reflective element 102 includes a dielectric substrate 104, a counter substrate 106, a patch electrode 108, a common electrode 110, a liquid crystal layer 114, a first alignment film 112a, and a second alignment film 112b. Within the reflective element 102, the dielectric substrate 104 can also be regarded as a single layer, i.e., a dielectric layer. The patch electrode 108 is provided on the dielectric substrate (dielectric layer) 104, and the common electrode 110 is provided on the counter substrate 106. A first alignment film 112a is provided on the dielectric substrate (dielectric layer) 104 so as to cover the patch electrode 108, and a second alignment film 112b is provided on the counter substrate 106 so as 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 provided 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 .

[0012] The patch electrode 108 preferably has a shape 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 (dielectric layer) 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 reflective elements are arranged, the first wiring 118 can be used to connect a patch electrode to an adjacent patch electrode.

[0013] Although not shown in Figures 1(A) and (B), the dielectric substrate (dielectric layer) 104 and the counter substrate 106 are bonded together with a sealant. The dielectric substrate (dielectric layer) 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 so as to fill the gap between the dielectric substrate (dielectric layer) 104 and the counter substrate 106. The gap between the dielectric substrate (dielectric layer) 104 and the counter substrate 106 is 20 to 100 µm, and is, for example, 50 µm. A patch electrode 108, a common electrode 110, a first alignment film 112a, and a second alignment film 112b are provided between the dielectric substrate (dielectric layer) 104 and the counter substrate 106, and therefore, to be precise, the distance between the first alignment film 112a and the second alignment film 112b provided on the dielectric substrate 104 and the counter substrate 106 is the thickness of the liquid crystal layer 114. Although not shown in FIG. 1(B), a spacer may be provided between the dielectric substrate (dielectric layer) 104 and the counter substrate 106 to keep the distance constant.

[0014] A control signal is applied to the patch electrode 108 to control the orientation of the liquid crystal molecules in the liquid crystal layer 114. 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 of the liquid crystal molecules in the liquid crystal layer 114. The liquid crystal layer 114 is made of a liquid crystal material with dielectric anisotropy. 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 changes depending on the orientation 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.

[0015] The frequency bands of radio waves reflected by 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 orientation of the liquid crystal molecules in liquid crystal layer 114 changes in response to a control signal applied to patch electrode 108, but does not change substantially with the frequency of the radio waves irradiated onto patch electrode 108. Therefore, reflective element 102 can control the phase of the reflected radio waves without being affected by the radio waves themselves.

[0016] 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 affected by an electric field, and their long axes are aligned perpendicular to the surfaces of the patch electrode 108 and the common electrode 110. 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 between the counter electrode and the patch electrode).

[0017] 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.

[0018] 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. 1(B), when radio waves propagating through the air are reflected by the reflecting element 102, the radio waves pass through the dielectric substrate (dielectric layer) 104 twice. The dielectric substrate (dielectric layer) 104 is formed of a dielectric material such as glass or resin.

[0019] 2.Radio wave reflection device Next, the configuration of a radio wave reflecting device in which reflecting elements are integrated will be described.

[0020] 2-1. Radio wave reflection 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 with 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.

[0021] The radio wave reflecting device 100a has a structure in which a plurality of reflecting elements 102 are integrated on a single dielectric substrate (dielectric layer) 104. As shown in FIG. 3, the radio wave reflecting device 100 has a structure in which a dielectric substrate (dielectric layer) 104 on which a plurality of patch electrodes 108 are arranged and a counter substrate 106 on which a common electrode 110 is provided are stacked, and a liquid crystal layer (not shown) is provided between the two substrates. A radio wave reflector 120 is formed in a region where the plurality of patch electrodes 108 and the common electrode 110 overlap. The cross-sectional structure of the radio wave reflector 120, in terms of each patch electrode 108, is the same as the structure of the reflecting element 102 shown in FIG. 1(B). The dielectric substrate (dielectric layer) 104 and the counter substrate 106 are bonded together with a sealant 128, and a liquid crystal layer (not shown) is provided in a region inside the sealant 128.

[0022] The dielectric substrate (dielectric layer) 104 has a region facing the counter substrate 106, as well as a peripheral region 122 extending outward from the counter 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 connecting to an external circuit, and is connected to, for example, a flexible printed circuit board (not shown). A signal for controlling the first drive circuit 124 is input to the terminal section 126.

[0023] 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 (dielectric layer) 104. Furthermore, a plurality of first wirings 118 extending in the row direction (Y-axis direction) are arranged on the dielectric substrate (dielectric layer) 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).

[0024] The multiple 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 multiple first wirings 118. As a result, in the radio wave reflecting plate 120, a control signal is applied to each of the multiple 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)).

[0025] 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 wave of the radio wave incident on the radio wave reflector 120. In other words, the radio wave reflecting device 100a can control the propagation direction of the reflected wave of the radio wave 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).

[0026] 4 shows a schematic diagram of how the direction of propagation of a reflected wave changes depending on the two reflecting elements 102. When radio waves are incident on the first reflecting element 102a and the second reflecting element 102b in the same phase, different control signals (V1≠V2) are applied to the first reflecting element 102a and the second reflecting element 102b, resulting in a larger phase change in the reflected wave by the second reflecting element 102b than by the first reflecting element 102a. As a result, the phase of the reflected wave R1 reflected by the first reflecting element 102a differs from the phase of the reflected wave R2 reflected by the second reflecting element 102b (in FIG. 4, the phase of the reflected wave R2 leads the phase of the reflected wave R1), and the apparent direction of propagation of the reflected wave changes obliquely.

[0027] This principle can be applied to the radio wave reflecting device 100a shown in FIG. 3, and for example, the reflection direction can be controlled in one axis direction by controlling the amount of phase change by the reflecting elements for each row.

[0028] 2-2. Radio wave reflection device B (two-axis reflection control) The radio wave reflecting device 100a shown in Fig. 3 has a single reflection axis VR, so the reflection angle can be controlled in the direction around the reflection axis VR as the rotation axis. 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.

[0029] 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.

[0030] FIG. 5 shows an enlarged inset of the arrangement of four patch electrodes 108, two first wirings 118, and a second wiring 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.

[0031] 5 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, the radio wave reflecting device 100 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), and therefore 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.

[0032] This principle can be applied to the radio wave reflecting device 100b shown in Figure 5, and 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.

[0033] 3. Drive method Next, a method for driving the radio wave reflecting device 100 will be described.

[0034] Fig. 6 shows the arrangement of the reflecting elements 102 in the radio wave reflecting device 100 shown in Fig. 3 and Fig. 5. As shown in Fig. 6, the reflecting elements 102 are arranged in the column direction (X-axis direction) from the first row (R1) to the tenth row (R10), and in the row direction (Y-axis direction) from the first column (C1) to the eleventh column (C11).

[0035] 3-1. Reflection direction control-1 A method of driving the radio wave reflecting device 100a that controls the reflection direction in the column direction (X-axis direction) will be described with reference to FIG.

[0036] 6, the arrangement of the multiple reflecting elements 102 of the radio wave reflecting device 100a is divided into a first region 136 and a second region 138. The first region 136 and the second region 138 are arranged adjacent to each other and are repeatedly arranged in at least one direction, either the column direction (X-axis direction) or the row direction (Y-axis direction).

[0037] The plurality of reflective elements 102 divided into the first region 136 are arranged in a column direction, and the amount of phase change is controlled for each column. The plurality of reflective elements 102 divided into the second region 138 are arranged in a column direction, and the amount of phase change is controlled for every two adjacent columns. Furthermore, the plurality of reflective elements 102 belonging to the first region 136 and the second region 138 are driven simultaneously. The amount of phase change controlled by the reflective elements 102 belonging to the second region 138 is greater than the amount of phase change controlled by the reflective elements 102 belonging to the first region 136.

[0038] A method of driving the radio wave reflecting device 100 shown in Fig. 6 will be specifically described with reference to Fig. 7. The voltage settings shown in Fig. 7 show an example of reflection control in one dimension. Fig. 7 shows the phase change amounts (phase settings) of the reflected waves set in the multiple reflecting elements 102 shown in Fig. 6 and the voltages (voltage settings) applied to the reflecting elements 102 corresponding to each phase change amount.

[0039] It is preferable that the radio wave reflecting device used in the driving method shown in FIG. 7 is the radio wave reflecting device shown in FIG. 5, which controls the amount of phase change by the reflecting elements independently for both columns and rows.

[0040] As shown in FIG. 7, the same voltage is applied to the plurality of reflective elements 102 arranged in the same column, and different voltages are applied to the plurality of reflective elements 102 arranged in the same row.

[0041] As shown in FIG. 7, the reflective elements 102 arranged in columns C1 to C5 of the first region 136 shown in FIG. 6 are set to have phase shift amounts of 0°, 60°, 120°, 180°, and 240° for each column. A voltage V0 is applied to the reflective elements 102 arranged in column C1, which is set to have a phase shift amount of 0°. Voltages V1, V2, V3, and V4 are also applied to the reflective elements 102 arranged in columns C2 to C5, respectively. The absolute values ​​of the voltages applied to the reflective elements 102 arranged in columns C1 to C5 among the reflective elements 102 belonging to the first region 136 increase in the order from voltage V0 to voltage V4, similar to the magnitude relationship of the phase shift amounts. The change from voltage V0 to voltage V4 is not a linear increase in voltage, but is appropriately set taking into account the change in the dielectric constant of the liquid crystal with respect to the applied voltage.

[0042] Furthermore, for the reflective elements 102 arranged in columns C8 to C11 in the first region 136, a phase change amount is set for each column, as with the reflective elements 102 arranged in columns C1 to C5, and voltages V1 to V4 corresponding to the phase change amount are applied to each column, respectively.

[0043] The reflective elements 102 belonging to the second region 138 are arranged in columns C6 and C7, respectively, and a phase change amount of, for example, 330°, which is considered a high phase difference, is set for the two columns C6 and C7. Here, the phase difference set in the second region 138 is preferably 270° or more and 360° or less. At this time, a voltage V5 is applied to the reflective elements 102 arranged in column C6, and a voltage V6 is applied to the reflective elements 102 arranged in column C7. The absolute value of voltage V5 is smaller than the absolute value of voltage V6 and is also smaller than the absolute value of voltage V4 applied to the reflective elements 102 arranged in column C5 of the first region 136. In other words, the voltage applied to the reflective elements 102 arranged in column C6 is smaller than the absolute values ​​of the voltages applied to the reflective elements 102 arranged in the adjacent columns C5 and C6.

[0044] 6 and 7 show examples of columns C1 to C5 in which the plurality of reflective elements 102 belonging to the first region 136 are arranged, and columns C6 and C7 in which the plurality of reflective elements 102 belonging to the second region 138 are arranged, but there is no limit to the number of columns of the plurality of reflective elements 102 belonging to the first region 136. For example, there may be columns C1 to Cn (n is a natural number greater than or equal to 3) in which the plurality of reflective elements 102 belonging to the first region 136 are arranged, and a phase change amount is set for the plurality of reflective elements 102 arranged in columns C1 to Cn for each column. Furthermore, voltages V0 to Vn are applied to the reflective elements 102 arranged in columns C1 to Cn for each column.

[0045] Next, the plurality of reflective elements 102 belonging to the second region 138 are arranged in adjacent columns Cn+1 and Cn+2. A phase change amount greater than the phase change amount set for the reflective elements 102 in the first region 136 is set for the plurality of reflective elements 102 arranged in these two adjacent columns. Furthermore, a combination of voltages Va and Vb is applied to the reflective elements 102 arranged in columns Cn+1 and Cn+2, respectively. Here, the absolute value of voltage Va is smaller than the absolute value of voltage Vb and the absolute value of voltage Vn; in other words, the absolute values ​​of voltages Vb and Vn are greater than the absolute value of voltage Va. Furthermore, the combination of voltages Va and voltage Vb may be set to voltages such that a composite wave of a wave reflected by a reflective element to which voltage Va is applied and a wave reflected by a reflective element to which voltage Vb is applied is greater than the phase change amount set for the first region 136.

[0046] Furthermore, the reflective elements 102 belonging to the first region 136 to which voltage Vn is applied can be aligned in the row direction with the reflective elements 102 belonging to the second region 138 to which voltage Va is applied and the reflective elements 102 belonging to the second region 138 to which voltage Vb is applied.

[0047] Furthermore, as described above, the voltage applied to the reflective elements 102 is applied to the patch electrodes 108 that constitute the reflective elements 102. Therefore, the patch electrodes 108 of the reflective elements 102 that belong to the first region 136 to which the voltage Vn is applied can be aligned in the row direction with the patch electrodes 108 of the reflective elements 102 that belong to the second region 138 to which the voltage Va is applied and the patch electrodes 108 of the reflective elements 102 that belong to the second region 138 to which the voltage Vb is applied.

[0048] In this way, within the surface of the radio wave reflecting device, in a first region, a phase change amount is set for each row and a corresponding voltage is applied, whereas in a second region, where the set value of the phase change amount is larger than that of the first region, two adjacent rows are treated as a pair and a predetermined voltage is applied within that pair, thereby widening the variable range of the reflection phase within the reflecting surface of the radio wave reflecting device.

[0049] 3-2. Reflection direction control-2 A driving method of the radio wave reflecting device 100 that controls the reflection direction in the column direction (X-axis direction) will be described with reference to Fig. 8. The difference from the driving method shown in Fig. 7 is that different voltages are applied to the reflecting elements 102 arranged in the same column among the plurality of reflecting elements 102 belonging to the second region 138. Note that a description of configurations that are the same as or similar to those in the driving method shown in Fig. 7 may be omitted.

[0050] The plurality of reflective elements 102 belonging to the second region 138 are aligned in the column direction. Specifically, as shown in FIG. 8, they are aligned along columns C6 and C7. As described above, voltages Va and Vb are applied to the plurality of reflective elements 102 belonging to the second region 138, respectively, and the plurality of reflective elements 102 belonging to the second region 138 are aligned in the row direction. Specifically, as shown in FIG. 8, voltage V5 or voltage V6 is applied to the plurality of reflective elements aligned along columns C6 and C7.

[0051] Similarly, the patch electrodes 108 of the reflective elements 102 belonging to the second region 138 are arranged in the column direction, specifically, along columns C6 and C7 as shown in Fig. 8. Voltages Va and Vb are applied to the patch electrodes 108, respectively, and the patch electrodes 108 are arranged in the row direction. Specifically, voltage V5 or voltage V6 is applied to the patch electrodes arranged in columns C6 and C7 as shown in Fig. 8.

[0052] In the second region 138, the voltage Vb is applied to the reflective element 102 adjacent in the column direction to the reflective element 102 to which the voltage Va is applied. Furthermore, in the second region 138, the voltage Va is applied to the reflective element 102 adjacent in the column direction to the reflective element 102 to which the voltage Vb is applied. Furthermore, in the second region 138, the multiple reflective elements 102 to which the voltage Va is applied are arranged diagonally to each other. Furthermore, in the second region 138, the multiple reflective elements 102 to which the voltage Vb is applied are arranged diagonally to each other.

[0053] 8, second region 138 is arranged in columns C6 and C7, and voltage V5 is applied to the reflective elements arranged in row R1 of column C6. Voltage V6 is applied to the reflective elements adjacent in the column direction to the reflective elements arranged in row R1 of column C6, and to the reflective elements arranged in row R2 of column C6. Voltage V6 is also applied to the reflective elements arranged in row R1 of column C7. Voltage V5 is applied to the reflective elements adjacent in the column direction to the reflective elements arranged in row R1 of column C7, and to the reflective elements arranged in row R2 of column C7.

[0054] The reflective elements arranged in row R1 of column C6 to which the voltage V5 is applied and the reflective elements arranged in row R2 of column C7 to which the voltage V5 is applied are arranged diagonally to each other. Also, the reflective elements arranged in row R2 of column C6 to which the voltage V6 is applied and the reflective elements arranged in row R1 of column C7 to which the voltage V6 is applied are arranged diagonally to each other.

[0055] 8 shows a combination of four reflective elements arranged diagonally to each other, but there is no limit to the number of reflective elements combined. For example, the reflective elements to which voltage V5 is applied can be set to the four reflective elements in rows R1 and R2 of columns C6 and C7 and the four reflective elements in rows R3 and R4 of columns C8 and C9 located diagonally thereto, and then the reflective elements to which voltage V6 is applied can be set to the four reflective elements in rows R1 and R2 of columns C8 and C9 and the four reflective elements in rows R3 and R4 of columns C6 and C7 located diagonally thereto.

[0056] In addition to the number of reflective elements described above, the four reflective elements arranged diagonally to each other can also be arranged in the row and column directions. For example, the voltage settings of the reflective elements in columns C6 and C7 shown in FIG. 8 can be further set to columns C8 and C9. Specifically, voltage V5 can be applied to odd-numbered rows R1, R3, etc. of column C8 and even-numbered rows R2, R4 of column C9, and voltage V6 can be applied to odd-numbered rows R1, R3, etc. of column C9 and even-numbered rows R2, R4 of column C8.

[0057] A voltage is similarly applied to the patch electrode 108 constituting the reflecting element 102 described above, and the patch electrode 108 is disposed in the same manner.

[0058] In this way, by equally controlling the voltages applied to the diagonally positioned reflecting elements among the four reflecting elements or their patch electrodes, a combination of voltages Va and Vb is applied in both the row and column directions, making it easier for the reflection characteristics of the radio wave reflecting device 100 for horizontally and vertically polarized waves to become equal.Furthermore, by applying a combination of voltages Vz and Vb, a high phase difference can be set in the radio wave reflecting device 100.

[0059] 3-3. Reflection direction control-3 A method for driving the radio wave reflecting device 100 that controls the reflection direction in a direction (diagonal direction) spanning the column direction (X-axis direction) and row direction (Y-axis direction) will be described with reference to Fig. 9. The difference from the driving method shown in Fig. 7 is that the arrangement of the multiple reflecting elements 102 belonging to the second region 138 is different for each row by one column. Note that a description of configurations that are the same as or similar to those of the driving method shown in Fig. 7 may be omitted.

[0060] The second regions 138 provided in each row are arranged in a different column from the second regions 138 provided in the next row. In the second regions 138 arranged in adjacent rows, the reflective elements 102 to which voltage Va is applied are arranged diagonally. In the second regions 138 arranged in adjacent rows, the reflective elements 102 to which voltage Vb is applied are arranged diagonally. In the second regions 138 arranged in adjacent rows, the reflective elements 102 to which voltage Va or voltage Vb is applied can be arranged in the same column.

[0061] Specifically, as shown in FIG. 9 , the second region 138 in row R1 is arranged in columns C6 and C7, and the second region 138 in row R2 adjacent to row R1 is arranged in columns C7 and C8. Of the multiple reflective elements in the second region 138 arranged in row R1, the reflective elements arranged in column C6 are applied with voltage V5, and of the multiple reflective elements in the second region 138 arranged in row R2, the reflective elements arranged in column C7 are applied with voltage V5. Therefore, the reflective elements arranged in column C6 of row R1 and the reflective elements arranged in column C7 of row R2 are arranged diagonally. Note that in FIG. 9 , the second region 138 is indicated by the reflective elements surrounded by dashed lines.

[0062] 9, voltage V6 is applied to the reflective elements arranged in column C7 among the plurality of reflective elements in second region 138 arranged in row R1, and voltage V6 is applied to the reflective elements arranged in column C8 among the plurality of reflective elements in second region 138 arranged in row R2. Therefore, the reflective elements arranged in column C7 of row R1 and the reflective elements arranged in column C8 of row R2 are arranged diagonally.

[0063] Similarly, a voltage is applied to the patch electrode 108 constituting the reflecting element 102 described above, and the patch electrode 108 is disposed in the same manner.

[0064] In this way, by varying the arrangement of the plurality of reflective elements 102 belonging to the second region 138 by one column for each row, it is possible to control the reflection direction in a diagonal direction relative to the row and column directions along which the reflective elements are arranged. Furthermore, by arranging the plurality of reflective elements 102 belonging to the second region 138 to which the same voltage is applied on a diagonal line, the radio wave reflecting device 100 can set a large phase difference.

[0065] As described above, the driving method of the radio wave reflecting device 100 according to one embodiment of the present invention has the first region 136 that controls the phase difference for each row and the second region 138 that controls the phase difference for every two rows, and by applying the voltage Va and the voltage Vb that is larger than the absolute value of the voltage Va to the plurality of reflecting elements 102 belonging to the second region 138, it is possible to set a large phase difference and widen the variable range of the reflection phase of the radio wave reflecting device 100. Furthermore, by applying the same voltage Va or Vb to the reflecting elements 102 arranged diagonally in the plurality of reflecting elements 102 belonging to the second region 138 that are arranged in the same row, the radio wave reflecting device 100 can exhibit equal reflection characteristics for horizontally and vertically polarized waves.

[0066] The driving methods of the radio wave reflecting device 100 exemplified as one embodiment of the present invention can be combined as appropriate as long as they are not mutually contradictory. Furthermore, a device in which a person skilled in the art appropriately adds or deletes components or modifies the design, or adds or omits processes or modifies conditions, based on the driving method of the radio wave reflecting device 100 disclosed in this specification and drawings, is also included in the scope of the present invention as long as it includes the gist of the present invention.

[0067] Even if there are other effects and advantages different from those brought about by the aspects of the embodiments disclosed in this specification, 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. [Explanation of symbols]

[0068] 100: radio wave reflecting device, 100a: radio wave reflecting device, 100b: radio wave reflecting device, 102: reflecting element, 102a: first reflecting element, 102b: second reflecting element, 104: dielectric substrate (dielectric layer), 106: opposing substrate, 108: 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 driving circuit, 132: second wiring, 134: switching element, 136: first area, 138: second area

Claims

1. A method for driving a radio wave reflecting device that has a plurality of reflecting elements arranged in row and column directions and controls the amount of phase change of a reflected wave by applying voltages to the plurality of reflecting elements, The array of the plurality of reflective elements is a first region that controls the amount of phase change of the plurality of reflecting elements arranged in the column direction for each column; a second region for controlling the amount of phase change for each two adjacent rows of the plurality of reflective elements arranged in the row direction; A method for driving a radio wave reflecting device, comprising simultaneously driving the plurality of reflecting elements belonging to the first area and the plurality of reflecting elements belonging to the second area.

2. 2. The method for driving a radio wave reflecting device according to claim 1, wherein the amount of phase change controlled by the plurality of reflecting elements belonging to the second region is greater than the amount of phase change controlled by the plurality of reflecting elements belonging to the first region.

3. Each of the plurality of reflective elements belonging to the first region and the second region has a patch electrode, a common electrode overlapping a rear surface side of the patch electrode, and a liquid crystal layer between the patch electrode and the common electrode, and voltages V0 to Vn are applied to the plurality of patch electrodes of the plurality of reflective elements belonging to the first region, respectively; applying a voltage combination of Va and Vb to each of the patch electrodes of the plurality of reflecting elements belonging to the second region; The n is a natural number of 3 or more, The absolute value of the voltage Vb is greater than the absolute value of the voltage Va, The absolute value of the voltage Vn is greater than the absolute value of the voltage Va. A method for driving the radio wave reflecting device according to claim 1.

4. Among the plurality of patch electrodes, a first patch electrode to which the voltage Vn is applied and a second patch electrode to which the voltage Va is applied are arranged along a row direction, Among the plurality of patch electrodes, the third patch electrode to which the voltage Vb is applied and the second patch electrode are arranged along the row direction. A method for driving the radio wave reflecting device according to claim 3.

5. the plurality of patch electrodes to which the voltage Va is applied are arranged diagonally to each other; A method for driving the radio wave reflecting device according to claim 3.

6. the plurality of patch electrodes to which the voltage Va is applied are arranged diagonally; A method for driving the radio wave reflecting device according to claim 3.

Images