Planar antenna and antenna device

Abstract

To provide a planar antenna equipped with a temperature-controllable metal-insulator phase transition element using a thin-film transistor circuit.SOLUTION: A planar antenna 1 includes an antenna substrate 11 on which are arranged at least one patch antenna P, a signal line LS electromagnetically coupled to the patch antenna P, and a metal-insulator phase transition element V provided on the signal line LS, and a temperature control substrate including a thin-film transistor circuit, having at least one heating element H temperature-controlled using the thin-film transistor circuit as a drive circuit. The antenna substrate and the temperature control substrate are laminated together such that heat from the heating element H can be conducted to the metal-insulator phase transition element V.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a planar antenna and an antenna device. [Background technology]

[0002] Phase change elements that utilize metal-insulator phase transition have been developed. Patent Document 1 discloses a switch using a phase change element. The phase change element in Patent Document 1 has metallic properties only within a specific temperature range. Patent Document 1 also discloses an example in which a vanadium dioxide thin film is used. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2017-504283 Summary of the Invention [Problem to be solved by the invention]

[0004] By using a phase-change element that utilizes a metal-insulator phase transition as a switch, a selectable phase shifter can be realized by controlling the temperature of the phase-change element. By arranging such phase shifters in an array in association with patch antennas, a phased array antenna can be constructed. For example, by using a thin-film transistor circuit (TFT circuit) containing thin-film transistors (TFTs) as a driving circuit and individually controlling the temperature of multiple phase-change elements, a phased array antenna that can transmit radio waves in a desired direction can be realized.

[0005] When using vanadium dioxide thin film as a phase-change element, additional high temperatures are applied after the TFT circuit manufacturing process to form a phase-change element containing a vanadium dioxide layer that undergoes a metal-insulator phase transition. The application of additional high temperatures can damage the TFT circuit. Therefore, it has been difficult to realize an antenna device equipped with a vanadium dioxide thin film that can be temperature-controlled by a TFT circuit using conventional manufacturing methods.

[0006] An object of the present disclosure is to provide a planar antenna and an antenna device equipped with a temperature-controllable metal-insulator phase transition element using a thin-film transistor circuit. [Means for solving the problem]

[0007] A planar antenna according to one embodiment of the present disclosure comprises an antenna substrate on which at least one patch antenna, a signal line connected to the patch antenna, and a metal-insulator phase transition element provided on the signal line are arranged, and a temperature control substrate on which at least one heat generating element including a thin film transistor circuit and whose temperature is controlled by the thin film transistor circuit is arranged, and the antenna substrate and the temperature control substrate are bonded together so that heat from the heat generating element can be conducted to the metal-insulator phase transition element. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a planar antenna and an antenna device equipped with a temperature-controllable metal-insulator phase transition element using a thin-film transistor circuit. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a conceptual diagram illustrating an example of the configuration of a planar antenna according to the present disclosure. [Figure 2] 1 is a conceptual diagram showing a cross section of a portion of a planar antenna according to the present disclosure. [Figure 3] 1 is a conceptual diagram showing an example of the positional relationship between a phase change switch and a heating element included in a planar antenna according to the present disclosure. [Figure 4] 10 illustrates an example of a state in which a heating element associated with a phase change switch included in a planar antenna according to the present disclosure generates heat. [Figure 5] 1 is a conceptual diagram showing an example of the configuration of an antenna substrate included in a planar antenna according to the present disclosure. [Figure 6] 1 is a conceptual diagram showing an example of the configuration of an antenna substrate included in a planar antenna according to the present disclosure. [Figure 7] 1 is a conceptual diagram illustrating an example of a heat conduction structure included in a planar antenna according to the present disclosure. [Figure 8] 1 is a conceptual diagram illustrating an example of a heat conduction structure included in a planar antenna according to the present disclosure. [Figure 9] 1 is a conceptual diagram illustrating an example of a heat conduction structure included in a planar antenna according to the present disclosure. [Figure 10] 1 is a conceptual diagram illustrating an example of an extension structure of a phase shifter included in a planar antenna according to the present disclosure. [Figure 11] FIG. 1 is a conceptual diagram illustrating an example of the configuration of a planar antenna according to the present disclosure. [Figure 12] 1 is a conceptual diagram showing a cross section of a portion of a planar antenna according to the present disclosure. [Figure 13] 1 is a conceptual diagram showing an example of the positional relationship between a phase change switch and a heating element included in a planar antenna according to the present disclosure. [Figure 14] 1 is a conceptual diagram illustrating an example of a heat conduction structure included in a planar antenna according to the present disclosure. [Figure 15] 1 is a conceptual diagram illustrating an example of an extension structure of a phase shifter included in a planar antenna according to the present disclosure. [Figure 16] 1 is a conceptual diagram illustrating an example of the configuration of an antenna device according to the present disclosure. [Figure 17] 1 is a block diagram illustrating an example of a configuration of an antenna device according to the present disclosure. [Figure 18] 1 is a conceptual diagram illustrating an example of the configuration of a planar antenna according to the present disclosure. [Figure 19] FIG. 2 is a block diagram illustrating an example of a hardware configuration for executing control in the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments for implementing the present disclosure will be described with reference to the drawings. In this disclosure, the drawings used in the description of each embodiment relate to one or more embodiments. Furthermore, elements included in each drawing may apply to one or more embodiments. The embodiments described below are limited in a manner that is technically preferable for implementing the present disclosure, but this does not limit the scope of the disclosure to the following. In all drawings used to describe the following embodiments, similar parts are designated by the same reference numerals unless otherwise specified. In the following embodiments, repeated description of similar configurations and operations may be omitted. The direction of arrows in the drawings is an example and does not limit the direction of signals, etc.

[0011] (First embodiment) First, a planar antenna according to a first embodiment will be described with reference to the drawings. The planar antenna of this embodiment includes a planar patch antenna. In the following, description of transmission control for transmitting radio waves from the planar antenna and reception control for receiving radio waves received by the planar antenna will be omitted. For example, the planar antenna of this embodiment is used for transmitting and receiving electromagnetic waves in a high frequency band that is expected to be applied to mobile communications of B5G (Beyond 5th Generation), which follows 5G (5th Generation). For example, the planar antenna of this embodiment is used for transmitting and receiving millimeter wave and terahertz wave signals. The planar antenna of this embodiment may also be used for transmitting and receiving signals other than millimeter wave and terahertz wave signals.

[0012] (composition) FIG. 1 is a conceptual diagram showing an example of the configuration of a planar antenna according to the present disclosure. FIG. 1 shows an example of the appearance of the planar antenna. The planar antenna 1 includes an antenna substrate 11 and a temperature control substrate 13. An antenna array 10 composed of multiple patch antennas P is arranged on the upper surface of the antenna substrate 11. The multiple patch antennas P that make up the antenna array 10 are arranged in a two-dimensional array. The multiple patch antennas P are arranged in a phased array. Each patch antenna P constitutes an antenna element. Each antenna element is controlled independently. The temperature control substrate 13 includes a TFT circuit (not shown) composed of TFTs (Thin Film Transistors). The TFT circuit is used to select a patch antenna P to be used for transmitting and receiving radio waves. In this embodiment, a description of the control circuit and the like that controls the planar antenna 1 will be omitted.

[0013] FIG. 2 is a conceptual diagram showing a cross section of a portion of a planar antenna according to the present disclosure. FIG. 2 shows a cross section of the planar antenna cut along the AA cutting line shown in FIG. 1. FIG. 3 is a conceptual diagram showing an example of the positional relationship between a phase change switch and a heating element provided in a planar antenna according to the present disclosure. FIG. 3 is a plan view looking down on the planar antenna from an upper viewpoint. The phase change switch V is disposed above the heating element H. The phase change switch V is connected to the first signal line L by a contact structure C. S1 and the second signal line L S2 3, a temperature control line for controlling the temperature of the heating element intersects with a signal line through which a phase-shifted signal propagates. Therefore, a shielding structure (not shown) is provided between the temperature control line and the signal line at the intersection of the temperature control line and the signal line to prevent crosstalk.

[0014] 2 and 3 show one of the multiple antenna elements that make up the planar antenna. A phase change switch V is arranged on the lower surface of the antenna substrate 11. A heating element H is arranged on the upper surface of the temperature control substrate 13. The phase change switch and the heating element H are arranged in positions facing each other. The phase change switch V and the heating element H are arranged with a gap between them. The gap between the phase change switch V and the heating element H is set to a distance that allows heat radiated from the heating element H to be conducted to the phase change switch V.

[0015] The phase-change switch V contains vanadium dioxide. Vanadium dioxide undergoes an insulating-metallic phase transition at around 67 degrees Celsius. The phase-change switch V is a phase-change switch that utilizes the insulating-metallic phase transition of vanadium dioxide. In other words, the phase-change switch V is an example of a phase-change element that utilizes a metal-insulator phase transition. The phase-change switch V may be made of a material other than vanadium dioxide. For example, the phase-change switch V may be made of a material such as a composite oxide containing vanadium dioxide or an oxide containing a 3d transition metal. The phase-change switch V may be made of a material with a transition temperature that corresponds to the temperature of the environment in which the planar antenna is used.

[0016] For example, the phase-change switch V may be formed using a sputtering method with a vanadium metal or vanadium dioxide target. For example, the phase-change switch V may be formed using a pulsed laser method with a vanadium dioxide target. For example, the phase-change switch V may be formed using a sol-gel method, an inkjet method, or screen printing. Regardless of the method used, high-temperature annealing is required to form the phase-change switch V containing vanadium dioxide that undergoes an insulating-metallic phase transition.

[0017] The phase-change switch V includes vanadium dioxide that undergoes a phase transition from an insulating phase to a metallic phase at a phase transition temperature. For example, the phase-change switch V includes vanadium dioxide without any additive elements. The ratio of oxygen to vanadium in the vanadium dioxide is adjusted to a ratio at which a phase transition from the insulating phase to the metallic phase occurs. For example, the vanadium dioxide in the phase-change switch V may include an additive element. For example, adding an additive element such as tungsten, magnesium, tantalum, iron, molybdenum, fluorine, or niobium to vanadium dioxide lowers the phase transition temperature. For example, adding chromium, aluminum, or germanium to vanadium dioxide raises the phase transition temperature.

[0018] At temperatures lower than the phase transition temperature, vanadium dioxide is in an insulating phase. Therefore, at temperatures lower than the phase transition temperature, phase transition switch V is in the OFF state. At temperatures higher than the phase transition temperature, vanadium dioxide is in a metallic phase. Therefore, at temperatures higher than the phase transition temperature, phase transition switch V is in the ON state. The resistance change during the phase transition between the insulating phase and the metallic phase of vanadium dioxide exhibits hysteresis characteristics. Therefore, taking hysteresis characteristics into consideration, the temperature of phase transition switch V is adjusted to cross the phase transition temperature.

[0019] The temperature of the heating element H associated with the phase change switch V is controlled according to the selection made via the TFT circuit. The heating element H is made of a material with high electrical resistance that easily generates heat when current is applied. For example, the heating element H is made of a material containing a nickel-chromium alloy or a chromium-iron-aluminum alloy. The selected heating element H is configured to generate heat up to a temperature at which the vanadium dioxide contained in the associated phase change switch V undergoes a phase transition to a metallic phase. When the heating element H is not generating heat, the vanadium dioxide is in an insulating phase. When the vanadium dioxide is in the insulating phase, the phase change switch V is in an OFF state.

[0020] When the selected heating element H generates heat, the vanadium dioxide contained in the phase change switch V rises in temperature due to the heat radiated from the heating element H. When the temperature of the vanadium dioxide contained in the phase change switch V exceeds the phase transition temperature, the vanadium dioxide undergoes a phase transition from the insulating phase to the metallic phase. When the vanadium dioxide contained in the phase change switch V undergoes a phase transition to the metallic phase, the phase change switch V transitions to the ON state. When the heating element H stops generating heat and the temperature of the vanadium dioxide falls below the phase transition temperature, the vanadium dioxide undergoes a phase transition from the metallic phase to the insulating phase. When the vanadium dioxide contained in the phase change switch V undergoes a phase transition to the insulating phase, the phase change switch V transitions to the OFF state.

[0021] The antenna substrate 11 includes a first substrate 110 and a second substrate 120. The first substrate 110 and the second substrate 120 are insulators (dielectrics). The first substrate 110 and the second substrate 120 are made of a material with low dielectric loss. The first substrate 110 and the second substrate 120 are preferably made of a material with high insulation and low dielectric loss, such as a ceramic material or glass. The first substrate 110 and the second substrate 120 may be made of a polymer or synthetic material. The lower the dielectric loss of the first substrate 110 and the second substrate 120, the more effectively they can control electromagnetic waves such as high frequency waves and microwaves. For example, at least one of the first substrate 110 and the second substrate 120 may be made of a multilayer substrate with low transmission loss. For example, at least one of the first substrate 110 and the second substrate 120 may be made of an alumina substrate.

[0022] A patch antenna P is disposed on the upper surface of the first substrate 110. A ground layer G is disposed between the lower surface of the first substrate 110 and the upper surface of the second substrate 120. A slot S is formed in the ground layer G. The slot S is formed below the patch antenna P. A phase change switch V is disposed on the lower surface of the second substrate 120. A first signal line L connected to the phase change switch V is also disposed on the lower surface of the second substrate 120. S1 and the second signal line L S2 The first signal line L S1is connected to a signal source (not shown) via a phase shift wiring (not shown). S1 is a line through which a signal whose phase has been shifted by the phase shift wiring is propagated. S2 The second signal line L extends to below the patch antenna P. S2 is a line for propagating the phase-shifted signal to the patch antenna P. The second signal line L S2 A slot S is interposed between the phase change switch V and the patch antenna P. S1 , and the second signal line L S2 The layer on which the layer is disposed forms a phase shift layer.

[0023] The patch antenna P is a plate-shaped radiating element. For example, the patch antenna P is rectangular. The shape of the patch antenna P is not limited to rectangular, but may be circular or another shape. The patch antenna P is fed by an electromagnetic coupling feeding method. The patch antenna P is connected to the second signal line L formed on the lower surface of the second substrate 120 via a slot S. S2 The patch antenna P and the second signal line L are electromagnetically coupled through the slot S. S2 The patch antenna P is excited by electromagnetic coupling between the first signal line L and the second signal line L. The patch antenna P has a structure equivalent to a microstrip line with both ends open. The resonant frequency of the patch antenna P is an integer multiple of the wavelength corresponding to the length of one side of the patch antenna P. The size of the patch antenna P is set according to the wavelength of the radio wave to be transmitted. The patch antenna P is connected to the second signal line L via a conductor. S2 The patch antenna P may be configured to be connected to the second signal line L S2 and the second signal line L S2 In this case, the phase shift line disposed on the phase shift layer and the second signal line L S2 are configured to be electromagnetically coupled to each other.

[0024] The ground layer G is disposed between the first substrate 110 and the second substrate 120. The ground layer G may be formed on the lower surface of the first substrate 110 or on the upper surface of the second substrate 120. The ground layer G blocks electromagnetic coupling above and below the ground layer G. The ground layer G is made of a conductor. For example, the material of the ground layer G is a metal (including alloys) such as copper, aluminum, or chromium. The potential of the ground layer G is the ground potential. Therefore, the phase change switch V, the first signal line L S1 , second signal line L S2 Between the ground layer G and the phase-shift layer including the phase-shift wiring (not shown), a capacitance according to the dielectric constant of the second substrate 120 is formed.

[0025] The temperature control substrate 13 is a substrate on which a TFT circuit is formed. For example, the material of the temperature control substrate 13 is an insulator (dielectric). The temperature control substrate 13 is made of a material with low dielectric loss. For example, the temperature control substrate 13 is made of a material with high insulation and low dielectric loss, such as a ceramic material or glass. The temperature control substrate 13 may be made of a polymer or synthetic material. The lower the dielectric loss of the temperature control substrate 13, the more effectively it can control electromagnetic waves such as high frequency waves and microwaves. For example, the temperature control substrate 13 is made of a multilayer substrate with low transmission loss. For example, the temperature control substrate 13 may be made of an alumina substrate.

[0026] A driving circuit D and a heating element H are arranged on the upper surface of the temperature control board 13. The driving circuit D and the heating element H are connected to each other via a temperature control line L HThe driving circuit D is one element that constitutes the TFT circuit. The layer on which the heating elements H are arranged has TFT wiring (not shown) formed thereon for controlling the temperature of the heating elements H. The TFT wiring includes multiple selection lines used to select the driving circuit D (phase shifter) and multiple data lines used to write phase shift data to the phase shifter. When the driving circuit D is selected, the heating elements H generate heat. The heat from the heating elements H is conducted to the phase transition switch V arranged above the heating elements H. The resistance change during the phase transition between the insulating phase and the metallic phase of vanadium dioxide exhibits hysteresis characteristics. Therefore, taking the hysteresis characteristics into consideration, the temperature of the heating elements H is controlled so that the temperature of the phase transition switch V crosses the phase transition temperature.

[0027] FIG. 4 shows an example of a state in which a heating element associated with a phase transition switch included in a planar antenna according to the present disclosure generates heat. When a drive circuit D is selected, the heating element H generates heat. The temperature of the phase transition switch V rises due to heat dissipation from the heated heating element H. When the temperature of the phase transition switch V exceeds the insulating phase-metal phase transition temperature, the phase transition switch V transitions to ON. When the phase transition switch V transitions to ON, radio waves transmitted from a signal source are transmitted through the phase shift wiring and the first signal line L. S1 via the second signal line L S2 The second signal line L S2 The radio waves propagate to the patch antenna P by electromagnetic coupling. The signal propagated to the patch antenna P is transmitted as a radio signal from a phased array antenna made up of multiple patch antennas P.

[0028] The antenna substrate 11 and the temperature control substrate 13 are manufactured using different manufacturing processes. The antenna substrate 11 is annealed at high temperature to form a phase change switch V containing vanadium dioxide that undergoes a metal-insulator phase transition. On the other hand, the temperature control substrate 13 is manufactured using a TFT manufacturing process included in the manufacturing process of a liquid crystal panel. The antenna substrate 11 and the temperature control substrate 13 are bonded together so that the corresponding phase change switch V and the heating element H face each other. By bonding the antenna substrate 11 and the temperature control substrate 13 together, a phase change switch V and a heating element H are formed. The phase shift amount of the formed phase shifter is set according to the length of the phase shift wiring. There are no limitations on the structure or phase shift amount of the phase shift wiring.

[0029] When the antenna substrate 11 and the temperature control substrate 13 are manufactured together, a process of applying an additional high temperature after the manufacturing process of the TFT circuit is completed is included in order to form the phase change switch V in the temperature control substrate 13. If such a high temperature is applied to the temperature control substrate 13, there is a possibility that the TFT circuit included in the temperature control substrate 13 will be damaged. In the planar antenna 1, the antenna substrate 11 and the temperature control substrate 13 are manufactured using different manufacturing processes, so that an additional high temperature is not applied to the temperature control substrate 13 after the manufacturing process of the TFT circuit is completed. Therefore, the TFT circuit included in the temperature control substrate 13 will not be damaged. In other words, according to this embodiment, a planar antenna equipped with a phase change switch (phase change element) whose temperature can be controlled by a TFT circuit can be realized.

[0030] (antenna board) Next, specific examples of the antenna substrate provided in the planar antenna of this embodiment will be described with reference to the drawings. Below, an antenna type in which the first substrate includes an alumina substrate and a device transfer type manufactured using device transfer are shown. The following example is an example of an antenna substrate and does not limit the antenna substrate of this embodiment.

[0031] FIG. 5 is a conceptual diagram showing an example of the configuration of an antenna substrate included in a planar antenna according to the present disclosure. FIG. 5 shows a cross-sectional view of the antenna substrate. The antenna substrate 11-1 includes a first substrate 110 and a second substrate 120-1. The first substrate 110 shown in FIG. 5 is the same as the first substrate 110 shown in FIG. 2. The second substrate 120-1 is composed of two layers: an alumina substrate 121 and a silica layer 122. The alumina substrate 121 is made of aluminum oxide. The silica layer 122 is formed on the lower surface of the alumina substrate 121. The silica layer 122 is made of silicon dioxide. A ground layer G is formed on the lower surface of the first substrate 110. The lower surface of the ground layer G and the upper surface of the alumina substrate 121 are joined to form the antenna substrate 11-1. A phase change switch V, a first signal line L S1 , second signal line L S2 , and a phase-shift layer including a phase-shift wiring (not shown) is formed on the underside of the silicon dioxide. The alumina substrate 121 has the advantage that a material with low dielectric loss can be selected. However, the alumina substrate 121 has the disadvantage that heat from the heating element H tends to diffuse upward due to its high thermal conductivity. In the antenna substrate 11-1, a silica layer 122 is interposed between the alumina substrate 121 and the phase-change switch V. Therefore, the heat from the heating element H is insulated by the silica layer 122, making it difficult for it to diffuse to the alumina substrate 121. The configuration of FIG. 5 makes it possible to realize an antenna substrate including an alumina substrate with low dielectric loss.

[0032] FIG. 6 is a conceptual diagram showing an example of the configuration of an antenna substrate included in a planar antenna according to the present disclosure. FIG. 6 shows a cross-sectional view of the antenna substrate. The antenna substrate 11-2 includes a first substrate 110 and a second substrate 120-2. The first substrate 110 shown in FIG. 6 is the same as the first substrate 110 shown in FIG. 2. The second substrate 120-2 is composed of two layers: a dielectric substrate 123 and a silicon substrate 124. The dielectric substrate 123 is made of a ceramic material, glass, polymer, or synthetic material. The silicon substrate 124 is formed on the lower surface of the dielectric substrate 123. The silicon substrate 124 is made of silicon. A phase change switch V, a first signal line L S1 , second signal line L S2, and a phase shift layer including a phase shift wiring (not shown) is formed on the lower surface of the silicon substrate 124. The phase change switch V, the first signal line L S1 , second signal line L S2 The phase-shift layer including the phase-shift switch V, the first signal line L, and the phase-shift wiring is formed on the surface of the silicon substrate 124 by using a device transfer technique, which is a process technique for micro LEDs (Light Emitting Diodes). S1 , second signal line L S2 , and the phase shift wiring are transcription devices. The transcription devices include the phase transition switch V and the first signal line L. S1 , second signal line L S2 , and the phase-shift wiring are formed on a silicon substrate and made into a chip. S1 , second signal line L S2 , and the phase-shift wiring, etc. are transferred onto the surface of the silicon substrate 124. The ground layer G is formed on the upper surface of the dielectric substrate 123. The lower surface of the first substrate 110 and the upper surface of the ground layer G, and the lower surface of the dielectric substrate 123 and the upper surface of the silicon substrate 124 are bonded together to form the antenna substrate 11-2. The configuration of Figure 6 can simplify the manufacturing process of fine devices by using device transfer technology.

[0033] (heat conduction structure) Next, an example of a heat conduction structure included in the planar antenna of this embodiment will be described with reference to the drawings. The heat conduction structure is a structure that mediates heat conduction between the phase change switch and the heat generating element included in the planar antenna. In the following description of the heat conduction structure, the antenna substrate is illustrated as a single substrate, and wiring around the phase change switch V and the heat generating element H is omitted. The following example is an example of a heat conduction structure included in the planar antenna, and does not limit the heat conduction structure of this embodiment.

[0034] FIG. 7 is a conceptual diagram illustrating an example of a heat conduction structure included in a planar antenna according to the present disclosure. FIG. 7 shows a cross-sectional view of the planar antenna. A spacer 141 is disposed between the antenna substrate 11 and the temperature control substrate 13. For example, the spacer 141 can be formed using a liquid crystal process. For example, the spacer 141 can be formed by scattering spherical members around the phase change switch V and the heating element H and precisely controlling the gap between the antenna substrate 11 and the temperature control substrate 13 to a desired value. For example, the spacer 141 can be formed by patterning a resin. For example, the spacer 141 can be formed by sandblasting. The spacer 141 can be formed to surround the associated phase change switch V and heating element H. In this case, the spacer 141 can be formed to form a closed shape, such as a square, rectangle, polygon, circle, or ellipse, in a planar view. The gap between the phase change switch V and the heating element H is adjusted by adjusting the size of the spacer 141. For example, the distance between the phase change switch V and the heating element H is adjusted to a gap of 10 μm (micrometers) to several tens of μm. For example, the spacer 141 may be configured to seal the periphery of the phase change switch V and the heating element H. This configuration makes it possible to reduce the pressure in the space between the phase change switch V and the heating element H or to seal in a gas with high thermal conductivity. In the heat conduction structure of FIG. 7, the heat generated from the heating element H can be conducted to the phase change switch V via the gas filling the space between the antenna substrate 11 and the temperature control substrate 13. That is, in the heat conduction structure of FIG. 7, the heat generated from the heating element H can be conducted to the phase change switch V by thermal radiation through the space.

[0035] FIG. 8 is a conceptual diagram illustrating an example of a heat conduction structure included in a planar antenna according to the present disclosure. FIG. 8 shows a cross-sectional view of the planar antenna. A heat conduction sheet 142 is disposed between the antenna substrate 11 and the temperature control substrate 13. The heat conduction sheet 142 is made of a material with high thermal conductivity. The heat conduction sheet 142 may be a small piece that fits within the plane of the phase change switch V and the heating element H. For example, the heat conduction sheet 142 is configured to contact both the antenna substrate 11 and the temperature control substrate 13. For example, the heat conduction sheet 142 may be configured to contact only one of the antenna substrate 11 and the temperature control substrate 13. If the gap between the antenna substrate 11 and the temperature control substrate 13 is sufficiently small, the heat conduction sheet 142 may be configured to contact only one of the phase change switch V and the heating element H. Alternatively, the heat conduction sheet 142 may be configured not to contact both the antenna substrate 11 and the temperature control substrate 13. The heat conduction sheet 142 is interposed between the phase change switch V and the heating element H. For example, the distance between the phase-change switch V and the heating element H is adjusted according to the thickness of the thermally conductive sheet 142. For example, the thermally conductive sheet 142 may be configured to bond the antenna substrate 11 and the temperature control substrate 13. For example, the thermally conductive sheet 142 may be transferred to either the phase-change switch V or the heating element H using a micro LED manufacturing process. The antenna substrate 11 and the temperature control substrate 13 can be bonded by attaching the antenna substrate 11 and the temperature control substrate 13 together with the thermally conductive sheet 142 transferred to either the phase-change switch V or the heating element H. In the thermally conductive structure of FIG. 8, heat generated from the heating element H is conducted to the phase-change switch V via the thermally conductive sheet 142. That is, in the thermally conductive structure of FIG. 8, the heat generated from the heating element H is conducted to the phase-change switch V by thermal conduction via the thermally conductive sheet 142.

[0036] FIG. 9 is a conceptual diagram illustrating an example of a thermal conduction structure included in a planar antenna according to the present disclosure. FIG. 9 shows a cross-sectional view of the planar antenna. A thermally conductive layer 15 is disposed on the lower surface of the antenna substrate 11. For example, the thermally conductive layer 15 is made of a material with high thermal conductivity, such as alumina or silicon carbide. A phase-change switch V is disposed on the lower surface of the thermally conductive layer 15. A thermal conductor 143 is also disposed on the lower surface of the thermally conductive layer 15. For example, the thermal conductor 143 is formed by screen-printing a grease-like thermally conductive material. A heating element H, disposed on the upper surface of the temperature control substrate 13, is positioned away from below the phase-change switch V. The heating element H is disposed below the thermal conductor 143. The thermal conductor 143 and the thermally conductive layer 15 are interposed between the phase-change switch V and the heating element H. The heating element H is thermally connected to the phase-change switch V via the thermal conductor 143 and the thermally conductive layer 15. For example, the thermal conductor 143 may be configured to bond the antenna substrate 11 and the temperature control substrate 13. In the thermal conduction structure of Fig. 9, the heat generated from the heating element H is conducted to the phase change switch V via the thermal conductor 143 and the thermal conduction layer 15. That is, in the thermal conduction structure of Fig. 9, the heat generated from the heating element H is conducted to the phase change switch V by thermal conduction via the thermal conductor 143 and the thermal conduction layer 15.

[0037] (phase shifter) Next, an example of an extended structure of a phase shifter included in the planar antenna of this embodiment will be described with reference to the drawings. In this extended structure, a phase transition line is shared between multiple adjacent heat conduction layers. The line length of the phase transition line is controlled by controlling the temperature of the heating element H for each heat conduction layer.

[0038] FIG. 10 is a conceptual diagram showing an example of an extension structure of a phase shifter included in a planar antenna according to the present disclosure. FIG. 10 is a plan view looking down on a portion of the phase shifter (phase shift wiring) from an upper viewpoint. FIG. 10 shows a portion of the phase shift wiring having a switching structure similar to that of FIG. 9, and capable of extending the line length in response to the selection of a heating element. For example, the phase shifter is a variable line length phase shifter in which multiple phase shift wirings with different line lengths branch off from a main wiring in a side chain shape. For example, the phase shift wiring is a stub with an open end. Openable and closable selection switches (not shown) are disposed at the contact points between the multiple phase shift wirings and the main wiring. The phase shift wiring is selected in response to the opening and closing of the selection switches disposed at the contact points with the main wiring. The selection switches may be configured as phase transition switches. The line length of the phase shift wiring is set in response to the selection control of the heating elements H. The phase shift wiring is configured as a phase transition line S extending along the extension direction. V The phase-shift wiring includes a plurality of heat-conducting layers 150 arranged along the extending direction. V is disposed across the plurality of thermally conductive layers 150. V contains vanadium dioxide that undergoes a phase transition from an insulating phase to a metallic phase at a phase transition temperature. Each of the plurality of thermally conductive layers 150 is thermally connected to a heat-generating element H via a thermal conductor 144. The heat-generating element H connected to each of the plurality of thermally conductive layers 150 generates heat in response to selection via a drive circuit T.

[0039] When a selection switch arranged at a junction with the main wiring is selected and transitions to the ON state, the phase-shift line connected to the main wiring via the selection switch transitions to the ON state. When the heating element H connected to the phase-shift wiring generates heat, the heat is conducted to the thermal conduction layer 150 via the thermal conductor 144 thermally connected to the heating element H. The heat conducted to the thermal conduction layer 150 is transferred to the phase-transition line S in contact with the thermal conduction layer 150. V Phase transition line S V When the temperature of exceeds the insulating-metallic phase transition temperature, the phase transition line S V The phase transition line S that has undergone a phase transition to the metallic phase VIn the example of FIG. 10, the state in which the first and second heat conductors from the left are selected is shown by hatching. In this case, the line length of the phase shift wiring is the phase transition line S V The phase transition line S V When the temperature of the insulating phase falls below the phase transition temperature of the metallic phase, the phase transition line S V The phase of the phase-shift line changes to the isolated phase, shortening the line length of the phase-shift line. Also, when the selection switch located at the junction with the main line changes to the OFF state, the phase-shift line connected to the main line via the selection switch changes to the OFF state.

[0040] 10, the temperature control board, on which the temperature control lines for controlling the temperature of the heating elements are arranged, is separated from the antenna board, on which the signal lines for transmitting the phase-shifted signals are arranged. Therefore, a shielding structure to prevent crosstalk between the temperature control lines and the signal lines is not required.

[0041] As described above, the planar antenna of this embodiment includes an antenna substrate and a temperature control substrate. The antenna substrate includes at least one patch antenna, a signal line connected to the patch antenna, and a metal-insulator phase transition element provided on the signal line. The patch antennas are arranged in a two-dimensional array. For example, the patch antenna and the signal line are connected by electromagnetic coupling. For example, the antenna substrate includes a ground layer having an opening formed below the patch antenna for electromagnetically coupling the patch antenna and the signal line. The signal line includes a first signal line and a second signal line. The first signal line is connected to a signal source via a phase shifter associated with each of the patch antennas. The second signal line extends below the patch antennas. The second signal line is configured to be coupled to the patch antenna by electromagnetic coupling. The metal-insulator phase transition element is disposed between the first signal line and the second signal line. The temperature control substrate includes a thin-film transistor circuit and includes at least one heating element H whose temperature is controlled by the thin-film transistor circuit. The antenna substrate and the temperature control substrate are bonded together so that heat from the heating element can be conducted to the metal-insulator phase transition element. The antenna elements, each including a patch antenna, a metal-insulator phase transition element, and a heating element, constitute a phased array antenna.

[0042] In the planar antenna of this embodiment, the antenna substrate and the temperature control substrate can be manufactured using different manufacturing processes. Therefore, after the TFT circuit manufacturing process is completed, additional high temperatures are not applied to the temperature control substrate, and the thin film transistor circuit included in the temperature control substrate is not damaged. In other words, according to this embodiment, a planar antenna equipped with a temperature-controllable metal-insulator phase transition element using a thin film transistor circuit can be realized.

[0043] In one aspect of this embodiment, the metal-insulator phase transition element is a phase transition switch containing vanadium dioxide. The heating element is configured to generate heat in response to temperature control of the thin film transistor circuit up to a temperature exceeding the phase transition temperature at which the vanadium dioxide transitions from an insulating phase to a metallic phase. This aspect provides a planar antenna in which the metal-insulator phase transition element is made of vanadium dioxide.

[0044] In one aspect of this embodiment, a spacer is disposed between the antenna substrate and the temperature control substrate so as to surround the metal-insulator phase transition element and the heat-generating element. According to this aspect, by sealing the space in which the metal-insulator phase transition element and the heat-generating element are disposed, heat from the heat-generating element can be more efficiently conducted to the metal-insulator phase transition element.

[0045] In one aspect of the present embodiment, a thermally conductive sheet is disposed between the metal-insulator phase transition element and the heat-generating element. According to this aspect, the metal-insulator phase transition element and the heat-generating element are thermally connected via the thermally conductive sheet, which facilitates efficient conduction of heat from the heat-generating element to the metal-insulator phase transition element.

[0046] In one aspect of this embodiment, a thermally conductive layer is formed between the antenna substrate and the metal-insulator phase transition element. In a planar view, the metal-insulator phase transition element and the heat-generating element are positioned so as not to overlap each other. A thermal conductor is disposed between the heat-generating element and the thermally conductive layer. According to this aspect, the metal-insulator phase transition element and the heat-generating element are thermally connected via the thermally conductive layer and the thermal conductor, which facilitates efficient conduction of heat from the heat-generating element to the metal-insulator phase transition element. Furthermore, in this aspect, the metal-insulator phase transition element and the heat-generating element do not overlap each other in a planar view, thereby increasing the degree of freedom in designing dielectric properties, etc.

[0047] (Second embodiment) Next, a planar antenna according to a second embodiment will be described with reference to the drawings. The planar antenna of this embodiment is configured so that the phase change switch and the heating element are in contact with each other. In the following, the description of the same configuration as in the first embodiment will be omitted.

[0048] (composition) FIG. 11 is a conceptual diagram showing an example of the configuration of a planar antenna according to the present disclosure. FIG. 11 shows an example of the appearance of the planar antenna. The planar antenna 2 includes an antenna substrate 21 and a temperature control substrate 23. An antenna array 20 composed of multiple patch antennas P is arranged on the upper surface of the antenna substrate 21. The multiple patch antennas P that make up the antenna array 20 are arranged in a two-dimensional array. The multiple patch antennas P are arranged in a phased array. Each patch antenna P constitutes an antenna element. Each antenna element is controlled independently. The temperature control substrate 23 includes a TFT circuit (not shown) composed of TFTs (Thin Film Transistors). The TFT circuit is used to select a patch antenna P to be used for transmitting and receiving radio waves. In this embodiment, a description of the control circuit and the like that controls the planar antenna 2 will be omitted.

[0049] 12 is a conceptual diagram showing a cross section of a portion of a planar antenna according to the present disclosure. FIG. 12 shows a cross section of the planar antenna cut along the BB section line shown in FIG. 11. FIG. 13 is a conceptual diagram showing an example of the positional relationship between a phase change switch and a heating element provided in a planar antenna according to the present disclosure. FIG. 13 is a plan view looking down on the planar antenna from an upper viewpoint. A heating element H is disposed on the underside of the phase change switch V. The phase change switch V is connected to the first signal line L by a contact structure C. S1 and the second signal line L S213, a temperature control line for controlling the temperature of the heating element intersects with a signal line through which a phase-shifted signal propagates. Therefore, a shielding structure (not shown) is provided between the temperature control line and the signal line at the intersection of the temperature control line and the signal line to prevent crosstalk. Note that in the structure of this embodiment, a sufficient gap can be provided between the temperature control line and the signal line, so a shielding structure is not necessary.

[0050] 12 and 13 show one of the multiple antenna elements that make up the planar antenna. A phase change switch V and a heating element H are arranged on the underside of the antenna substrate 21. The heating element H is formed on the underside of the phase change switch V. A pair of bumps B is formed on the upper surface of the temperature control substrate 23. The pair of bumps B are connected to the heating element H. The heating element H has a rectangular shape that extends in one direction. The heating element H is arranged so as to straddle the phase change switch V. The heating element H generates heat in response to selection control via the pair of bumps B. The heat radiated from the heating element H is transferred directly to the phase change switch V.

[0051] The phase-change switch V has the same configuration as the phase-change switch V of the first embodiment. The phase-change switch V is temperature-controlled in the same manner as the phase-change switch V of the first embodiment. The phase-change switch V contains vanadium dioxide, which undergoes a phase transition from an insulating phase to a metallic phase at a phase transition temperature. Vanadium dioxide is in the insulating phase at temperatures lower than the phase transition temperature. Therefore, the phase-change switch V is in the OFF state at temperatures lower than the phase transition temperature. Vanadium dioxide is in the metallic phase at temperatures higher than the phase transition temperature. Therefore, the phase-change switch V is in the ON state at temperatures higher than the phase transition temperature. The resistance change during the phase transition between the insulating phase and the metallic phase of vanadium dioxide exhibits hysteresis characteristics. Therefore, taking the hysteresis characteristics into consideration, the temperature of the phase-change switch V is adjusted to cross the phase transition temperature.

[0052] The antenna substrate 21 has the same configuration as the antenna substrate 11 of the first embodiment. The antenna substrate 21 includes a first substrate 210 and a second substrate 220. A patch antenna P is arranged on the upper surface of the first substrate 210. A ground layer G is arranged between the lower surface of the first substrate 210 and the upper surface of the second substrate 220. A slot S is formed in the ground layer G. The slot S is formed below the patch antenna P. A phase change switch V is arranged on the lower surface of the second substrate 220. In addition, a first signal line L connected to the phase change switch V is also arranged on the lower surface of the second substrate 220. S1 and the second signal line L S2 The first signal line L S1 The second signal line L is connected to a signal source (not shown) via a phase shift wiring (not shown). S2 The second signal line L extends to below the patch antenna P. S2 A slot S is interposed between the phase change switch V and the patch antenna P. S1 , and the second signal line L S2 The layer on which the layer is disposed forms a phase shift layer.

[0053] The patch antenna P has the same configuration as the patch antenna P of the first embodiment. The patch antenna P is connected to the second signal line L formed on the lower surface of the second substrate 220 via the slot S. S2 The patch antenna P and the second signal line L are electromagnetically coupled through the slot S. S2 The patch antenna P is excited by electromagnetic coupling between the first signal line L and the second signal line L. S2 The patch antenna P may be configured to be connected to the second signal line L S2 and the second signal line L S2 In this case, the phase shift line disposed on the phase shift layer and the second signal line L S2 are configured to be electromagnetically coupled to each other.

[0054] The ground layer G has the same configuration as the ground layer in the first embodiment. The ground layer G is disposed between the first substrate 210 and the second substrate 220. The ground layer G blocks electromagnetic coupling above and below the ground layer G. The potential of the ground layer G is the ground potential. Therefore, the phase change switch V and the first signal line L S1 , second signal line L S2 A capacitance according to the dielectric constant of the second substrate 220 is formed between the phase-shift layer including the phase-shift wiring (not shown) and the ground layer G. In the structure of this embodiment, the ground layer G may be omitted.

[0055] The temperature control board 23 has the same configuration as the temperature control board 13 of the first embodiment. A drive circuit D is disposed on the upper surface of the temperature control board 23. The heat generating element H is connected to a pair of bumps B formed on the upper surface of the temperature control board 23. The bumps B can be formed by bumps used in flip-chip mounting. The drive circuit D and the heat generating element H are connected to the temperature control line L. H and bumps B. The driving circuit D is one element that constitutes the TFT circuit. The layer on which the heating element H is arranged has TFT wiring (not shown) formed therein for controlling the temperature of the heating element H when selecting the phase shifter to be controlled. The TFT wiring includes multiple selection lines used to select the phase shifter and multiple data lines used to write phase shift data to the phase shifter. When the driving circuit D is selected, the heating element H generates heat. The heat from the heating element H is conducted to the phase change switch V. The resistance change during the phase change between the insulating phase and the metallic phase of vanadium dioxide exhibits hysteresis characteristics. Therefore, taking the hysteresis characteristics into consideration, the temperature of the heating element H is controlled so that the temperature of the phase change switch V crosses the phase change temperature.

[0056] The antenna substrate 21 and the temperature control substrate 23 are manufactured using different manufacturing processes. The antenna substrate 21 is annealed at high temperature to form a phase change switch V containing vanadium dioxide that undergoes a metal-insulator phase transition. On the other hand, the temperature control substrate 23 is manufactured using a TFT manufacturing process included in the manufacturing process of a liquid crystal panel. The antenna substrate 21 and the temperature control substrate 23 are bonded together so that the corresponding phase change switch V and heating element H face each other. By bonding the antenna substrate 21 and the temperature control substrate 23 together, a phase shifter including the phase change switch V and the heating element H is formed. The phase shift amount of the formed phase shifter is set according to the length of the phase shift wiring. There are no limitations on the structure or phase shift amount of the phase shift wiring.

[0057] When the antenna substrate 21 and the temperature control substrate 23 are manufactured together, a process of applying an additional high temperature after the manufacturing process of the TFT circuit is completed is included in order to form the phase change switch V in the temperature control substrate 23. If such a high temperature is applied to the temperature control substrate 23, the TFT circuit included in the temperature control substrate 23 may be damaged. The planar antenna 2 is manufactured using different manufacturing processes for the antenna substrate 21 and the temperature control substrate 23. Therefore, no additional high temperature is applied to the temperature control substrate 23 after the manufacturing process of the TFT circuit is completed, and the TFT circuit included in the temperature control substrate 23 is not damaged. In other words, according to this embodiment, a planar antenna equipped with a phase change switch (phase change element) whose temperature can be controlled by a TFT circuit can be realized.

[0058] (heat conduction structure) Next, an example of a heat conduction structure included in the planar antenna of this embodiment will be described with reference to the drawings. The heat conduction structure is a structure that mediates heat conduction between the phase change switch and the heat generating element included in the planar antenna. In the following description of the heat conduction structure, the antenna substrate is illustrated as a single substrate, and wiring around the phase change switch V and the heat generating element H is omitted. The following example is an example of a heat conduction structure included in the planar antenna, and does not limit the heat conduction structure of this embodiment.

[0059] FIG. 14 is a conceptual diagram illustrating an example of a heat conduction structure included in a planar antenna according to the present disclosure. FIG. 14 shows a cross-sectional view of the planar antenna. A heat conduction layer 25 is disposed on the lower surface of the antenna substrate 21. The heat conduction layer 25 has the same configuration as the heat conduction layer 15 of the first embodiment. A phase change switch V is disposed on the lower surface of the heat conduction layer 25. A heating element H disposed on the upper surface of the temperature control substrate 23 is disposed in a position away from below the phase change switch V. The heating element H may be formed on the lower surface of the heat conduction layer 25. The heat conduction layer 25 is interposed between the phase change switch V and the heating element H. The heating element H is thermally connected to the phase change switch V via the heat conduction layer 25. In the heat conduction structure of FIG. 14, heat generated from the heating element H is conducted to the phase change switch V via the heat conduction layer 25. That is, in the heat conduction structure of FIG. 14, heat generated from the heating element H is conducted to the phase change switch V by thermal conduction via the heat conduction layer 25.

[0060] (phase shifter) Next, an example of an extended structure of a phase shifter included in a planar antenna according to this embodiment will be described with reference to the drawings. In this extended structure, a phase transition line is shared between multiple adjacent heat conduction layers. The line length of the phase transition line is controlled by controlling the temperature of the heating element H for each heat conduction layer.

[0061] FIG. 15 is a conceptual diagram showing an example of an extension structure of a phase shifter included in a planar antenna according to the present disclosure. FIG. 15 is a plan view looking down on a portion of the phase shifter (phase shift wiring) from an upper viewpoint. FIG. 15 shows a portion of the phase shift wiring having a switching structure similar to that of FIG. 14, and capable of extending the line length in response to the selection of a heating element. For example, the phase shifter is a variable line length phase shifter in which multiple phase shift wirings with different line lengths branch off from a main wiring in a side chain manner. For example, the phase shift wiring is a stub with an open end. Openable and closable selection switches (not shown) are disposed at the contact points between the multiple phase shift wirings and the main wiring. The phase shift wiring is selected in response to the opening and closing of the selection switches disposed at the contact points with the main wiring. The selection switches may be configured as phase transition switches. The line length of the phase shift wiring is set in response to the selection control of the heating elements H. The phase shift wiring is configured as a phase transition line S extending along the extension direction. V The phase-shift wiring includes a plurality of heat-conducting layers 250 arranged along the extending direction. V is disposed across the plurality of thermally conductive layers 250. V contains vanadium dioxide that undergoes a phase transition from an insulating phase to a metallic phase at a phase transition temperature. A heating element H is disposed on each of the plurality of thermally conductive layers 250. The heating element H disposed on each of the plurality of thermally conductive layers 250 generates heat in response to selection via a drive circuit T.

[0062] When a selector switch disposed at a contact point with the main wiring is selected and transitions to the ON state, the phase-shift line connected to the main wiring via the selector switch transitions to the ON state. When the heating element H connected to the phase-shift line generates heat, the heat is transferred to the phase-transition line S via the thermal conduction layer 250 on which the heating element H is disposed. V Phase transition line S V When the temperature of exceeds the insulating-metallic phase transition temperature, the phase transition line S V The phase transition line S that has undergone a phase transition to the metallic phase VIn the example of FIG. 15, the state in which the first and second heat conductors from the left are selected is shown by hatching. In this case, the line length of the phase shift wiring is determined by the phase transition line S V The phase transition line S V When the temperature of the insulating phase falls below the phase transition temperature of the metallic phase, the phase transition line S V The phase of the phase-shift line changes to the isolated phase, shortening the line length of the phase-shift line. Also, when the selection switch located at the junction with the main line changes to the OFF state, the phase-shift line connected to the main line via the selection switch changes to the OFF state.

[0063] 15, the temperature control board, on which the temperature control lines for controlling the temperature of the heating elements are arranged, is separated from the antenna board, on which the signal lines for transmitting the phase-shifted signals are arranged. Therefore, a shielding structure to prevent crosstalk between the temperature control lines and the signal lines is not required.

[0064] As described above, the planar antenna of this embodiment includes an antenna substrate and a temperature control substrate. The antenna substrate includes at least one patch antenna, a signal line connected to the patch antenna, and a metal-insulator phase transition element provided on the signal line. The patch antennas are arranged in a two-dimensional array. For example, the patch antenna and the signal line are connected by electromagnetic coupling. For example, the antenna substrate includes a ground layer having an opening formed below the patch antenna for electromagnetically coupling the patch antenna and the signal line. The signal line includes a first signal line and a second signal line. The first signal line is connected to a signal source via a phase shifter associated with each of the patch antennas. The second signal line extends below the patch antennas. The second signal line is configured to be coupled to the patch antenna by electromagnetic coupling. The metal-insulator phase transition element is disposed between the first signal line and the second signal line. The temperature control substrate includes a thin-film transistor circuit and includes at least one heating element disposed thereon whose temperature is controlled by the thin-film transistor circuit. The antenna substrate and the temperature control substrate are bonded together so that heat from the heating element can be conducted to the metal-insulator phase transition element. The heating element is arranged to contact the metal-insulator phase transition element via bumps formed on the surface of the temperature control substrate. The antenna elements, each including a patch antenna, a metal-insulator phase transition element, and a heating element, constitute a phased array antenna.

[0065] In the planar antenna of this embodiment, the antenna substrate and the temperature control substrate can be manufactured using different manufacturing processes. Therefore, after the TFT circuit manufacturing process is completed, additional high temperatures are not applied to the temperature control substrate, and the thin film transistor circuit included in the temperature control substrate is not damaged. That is, according to this embodiment, a planar antenna equipped with a temperature-controllable metal-insulator phase transition element using a thin film transistor circuit can be realized. Furthermore, according to this embodiment, since the heat-generating element is in contact with the metal-insulator phase transition element, the diffusion of heat conducted from the heat-generating element to the metal-insulator phase transition element is reduced, thereby suppressing energy loss.

[0066] (Third embodiment) Next, an antenna device according to a third embodiment will be described with reference to the drawings. The antenna device according to the present disclosure includes the planar antenna according to the first embodiment and the second embodiment. The antenna device according to the present disclosure may also include the planar antenna according to the first embodiment and the second embodiment. The antenna device according to the present embodiment has a configuration in which a signal source, a control circuit, and the like are added to the planar antenna according to the first embodiment and the second embodiment. The following configuration is an example and does not limit the configuration of the antenna device according to the present disclosure.

[0067] (composition) FIG. 16 is a conceptual diagram showing an example of the configuration of an antenna device according to the present disclosure. FIG. 16 shows an example of the external appearance of an antenna device. The antenna device 300 includes a planar antenna 3. The planar antenna 3 includes the planar antenna of the first embodiment or the second embodiment. Details of the planar antenna 3 will not be described here. An antenna array 30 composed of a plurality of patch antennas P arranged in a two-dimensional array is disposed on the upper surface of the planar antenna 3. In the example of FIG. 16, the plurality of patch antennas P are arranged along the X direction and the Y direction. The plurality of patch antennas P are arranged in a phased array.

[0068] The antenna device 300 is equipped with a first drive circuit 371 and a second drive circuit 372. The first drive circuit 371 and the second drive circuit 372 are circuits used to specify the patch antenna P to be driven. By driving the first drive circuit 371 and the second drive circuit 372, it is possible to specify an address associated with each patch antenna P. For example, the first drive circuit 371 and the second drive circuit 372 are formed on the surface of the planar antenna 3. The first drive circuit 371 and the second drive circuit 372 may also be formed inside the planar antenna 3.

[0069] 17 is a block diagram showing an example of the configuration of an antenna device according to the present disclosure. The antenna device 300 includes an antenna array 30, a phase shifter 31, a matrix circuit 32, a driver circuit 37, a control circuit 38, and a signal source 39.

[0070] A phase shifter 31 is provided for each antenna unit. The phase shifter 31 includes a phase shift wiring, a first signal line, a second signal line, a phase change switch, a heating element, and a temperature control line. The phase shift amount of the phase shifter 31 is set according to the line lengths of the lines formed by the phase shift wiring, the first signal line, the second signal line, and the phase change switch, and the dielectric constants of the antenna substrate and the temperature control substrate.

[0071] The matrix circuit 32 has a configuration in which a plurality of thin film transistors (TFTs) are arranged in a two-dimensional array. The matrix circuit 32 is formed using TFT process technology. For example, a shield layer is formed above the matrix circuit 32. The shield layer is formed to prevent electromagnetic coupling between the top and bottom of the shield layer. For example, the shield layer includes a conductor. The potential of the shield layer is basically the ground potential. Therefore, a capacitance is formed between the signal line included in the phase shifter 31 and the shield layer according to the dielectric constant of a dielectric layer such as an insulating layer or a TFT substrate. Each of the plurality of TFTs included in the matrix circuit 32 corresponds to one of the plurality of patch antennas P included in the antenna array 30. For example, the TFT includes a semiconductor layer such as amorphous silicon or polysilicon.

[0072] The drive circuit 37 includes a first drive circuit 371 and a second drive circuit 372. The first drive circuit 371 is a circuit for specifying addresses in the X direction. The first drive circuit 371 is connected to a plurality of lines extending in the Y direction. The second drive circuit 372 is a circuit for specifying addresses in the Y direction. The second drive circuit 372 is connected to a plurality of lines extending in the X direction. The drive circuit 37 can specify addresses associated with each patch antenna P by controlling the first drive circuit 371 and the second drive circuit 372. The drive circuit 37 drives a plurality of TFTs included in the matrix circuit 32 under the control of the control circuit 38. The drive circuit 37 individually drives a plurality of TFTs arranged in a two-dimensional array.

[0073] The control circuit 38 drives the drive circuit 37 in response to an external control signal. The control circuit 38 drives the drive circuit 37 using an active matrix drive system. The control circuit 38 also outputs the external control signal to a signal source 39. For example, the control circuit 38 is implemented by a microcomputer (also called a microcomputer) or a microcontroller. For example, the control circuit 38 includes a central processing unit (CPU), random access memory (RAM), read-only memory (ROM), flash memory, etc. The control circuit 38 executes control according to a pre-stored program. The control circuit 38 executes control according to the program in accordance with a pre-set schedule, timing, external control instructions, etc. For example, the control circuit 38 controls the antenna array 30, which is composed of multiple patch antennas P included in the planar antenna 3, to transmit directional radio waves from the antenna array 30. In this way, the antenna array 30 is used as a phased array antenna.

[0074] The signal source 39 is connected to a switch group formed by a plurality of phase transition switches included in a plurality of antenna elements included in the phase shifter 31. The signal source 39 is also connected to the control circuit 38. The signal source 39 receives a control signal from the control circuit 38. The signal source 39 controls the ON / OFF of the plurality of phase transition switches that make up the switch group in response to the control signal. The signal source 39 may be configured to receive a control signal directly from the outside without going through the control circuit 38.

[0075] A signal that reaches the signal input section of the phase shifter 31 through a signal line (not shown) connected to an ON-state TFT is phase-shifted by an amount corresponding to the line length set in the phase shifter 31 and the dielectric constant of the dielectrics of the antenna substrate and the temperature control substrate. The phase-shifted signal propagates from the second signal line to the patch antenna P by electromagnetic coupling. The signal propagated to the patch antenna P is transmitted from the patch antenna P as a radio wave to be transmitted. The radio wave transmitted from the patch antenna P is based on a signal output from a transmitting circuit (not shown). There are no particular limitations on the information contained in the signal.

[0076] Furthermore, the radio waves received by the patch antenna P are received according to a capacitance based on the dielectric constant of the antenna substrate interposed between the patch antenna P and the second signal line. The phase of the received radio waves is shifted by an amount that depends on the line length set in the phase shifter 31 and the dielectric constants of the antenna substrate and the temperature control substrate. The phase-shifted signal is received by a receiving circuit (not shown) through the signal line. Information contained in the signal received by the receiving circuit is decoded by a decoder (not shown).

[0077] As described above, the antenna device of this embodiment includes the planar antenna, signal source, phase shifter, matrix circuit, drive circuit, and control circuit of the first or second embodiment. The signal source is connected to a metal-insulator phase transition element included in the planar antenna via a signal line. The phase shifter includes phase-shift wiring arranged between the metal-insulator phase transition element and the signal source. The matrix circuit includes a plurality of thin-film transistors connected to wiring included in the planar antenna, arranged in a two-dimensional array. The drive circuit drives the thin-film transistors included in the matrix circuit. The control circuit drives the drive circuit in response to a control signal. The antenna device of this aspect includes the planar antenna of the first or second embodiment. Therefore, this aspect can provide an antenna device equipped with a temperature-controllable metal-insulator phase transition element using a thin-film transistor circuit.

[0078] In one aspect of the present embodiment, the control circuit controls a plurality of patch antennas included in the planar antenna to transmit directional radio waves from an antenna array formed by the plurality of patch antennas. According to this aspect, the antenna array formed by the plurality of patch antennas can be used as a phased array antenna.

[0079] (Fourth embodiment) Next, a planar antenna according to a fourth embodiment will be described with reference to the drawings. The planar antenna according to this embodiment has a simplified configuration of the planar antennas according to the first and second embodiments. For example, the functions of the components of the planar antenna according to this embodiment are realized by the functions of the components of the planar antennas according to the first and second embodiments. For example, the planar antenna according to this embodiment is controlled by the control system of the antenna device according to the third embodiment.

[0080] 18 is a conceptual diagram showing an example of the configuration of a planar antenna according to the present disclosure. The planar antenna 4 includes an antenna substrate 41 and a temperature control substrate 43. The antenna substrate 41 includes at least one patch antenna P and a signal line L connected to the patch antenna P. S and signal line L S The temperature control substrate 43 includes a thin film transistor circuit, and at least one heat generating element H whose temperature is controlled by the thin film transistor circuit is disposed on the temperature control substrate 43. The antenna substrate and the temperature control substrate are bonded together so that heat from the heat generating element H can be conducted to the phase change element V (metal-insulator phase change element).

[0081] In the planar antenna of this embodiment, the antenna substrate and the temperature control substrate can be manufactured using different manufacturing processes. Therefore, after the TFT circuit manufacturing process is completed, additional high temperatures are not applied to the temperature control substrate, and the thin film transistor circuit included in the temperature control substrate is not damaged. In other words, according to this embodiment, a planar antenna equipped with a temperature-controllable metal-insulator phase transition element using a thin film transistor circuit can be realized.

[0082] (Hardware) Next, a hardware configuration for executing the control in the present disclosure will be described with reference to the drawings. Fig. 19 is a block diagram showing an example of a hardware configuration for executing the control in the present disclosure. Here, an information processing device 90 (computer) is shown as an example of the hardware configuration. The information processing device in Fig. 19 is an example of a configuration for executing the control in the present disclosure and does not limit the scope of the present disclosure.

[0083] 19, an information processing device 90 includes a processor 91, a memory 92, an auxiliary storage device 93, an input / output interface 95, and a communication interface 96. In FIG. 19, interface is abbreviated as I / F (Interface). The information processing device 90 may include at least a plurality of the processor 91, memory 92, auxiliary storage device 93, input / output interface 95, and communication interface 96. The processor 91, memory 92, auxiliary storage device 93, input / output interface 95, and communication interface 96 are connected to each other via a bus 98 so as to be able to communicate data with each other. The processor 91, memory 92, auxiliary storage device 93, and input / output interface 95 are also connected to a network such as the Internet or an intranet via the communication interface 96.

[0084] The processor 91 loads a program (instructions) stored in an auxiliary storage device 93 or the like into the memory 92. For example, the program is a software program for executing the control in the present disclosure. The processor 91 executes the program loaded into the memory 92. The processor 91 executes the control in the present disclosure by executing the program. The processor 91 may be configured by a single piece of hardware or may be configured by multiple pieces of hardware.

[0085] The memory 92 is a storage device having an area in which a program is loaded. The processor 91 loads a program stored in an auxiliary storage device 93 or the like into the memory 92. The memory 92 is realized by a volatile memory such as a DRAM (Dynamic Random Access Memory). Alternatively, a non-volatile memory such as an MRAM (Magnetoresistive Random Access Memory) may be used as the memory 92. The memory 92 may be configured by a single piece of hardware or by multiple pieces of hardware.

[0086] The auxiliary storage device 93 stores various data such as programs. For example, the auxiliary storage device 93 is realized by a local disk such as a hard disk or flash memory. The auxiliary storage device 93 may be configured by a single piece of hardware or by multiple pieces of hardware. The auxiliary storage device 93 may also be configured as external hardware. It is also possible to configure the system so that various data is stored in the memory 92, and omit the auxiliary storage device 93.

[0087] The input / output interface 95 is an interface for connecting the information processing device 90 to peripheral devices based on standards and specifications. The communication interface 96 is an interface for connecting to external systems and devices via a network such as the Internet or an intranet based on standards and specifications. The input / output interface 95 may be configured by a single piece of hardware, or may be configured by multiple pieces of hardware. The input / output interface 95 and the communication interface 96 may be a common interface for connecting to external devices.

[0088] Input devices such as a keyboard, mouse, and touch panel may be connected to the information processing device 90 as needed. These input devices are used to input information and settings. When a touch panel is used as the input device, a screen having the function of the touch panel serves as the interface. The processor 91 and the input devices are connected via an input / output interface 95.

[0089] The information processing device 90 may be equipped with a display device for displaying information. When a display device is equipped, the information processing device 90 is equipped with a display control device (not shown) for controlling the display of the display device. The information processing device 90 and the display device are connected via an input / output interface 95.

[0090] The information processing device 90 may be equipped with a drive device. The drive device acts as an intermediary between the processor 91 and a recording medium (program recording medium) to read data and programs stored on the recording medium and to write processing results of the information processing device 90 to the recording medium. The information processing device 90 and the drive device are connected via an input / output interface 95.

[0091] The above is an example of a hardware configuration for enabling the control in the present disclosure. The hardware configuration in Fig. 19 is an example of a hardware configuration for executing the control in the present disclosure and does not limit the scope of the present disclosure. A program that causes a computer to execute the control in the present disclosure is also included in the scope of the present disclosure.

[0092] A program recording medium on which a program for executing the processing in this embodiment is recorded is also included in the scope of the present invention. For example, the program recording medium is a computer-readable non-transitory recording medium. The recording medium can be realized as an optical recording medium such as a CD (Compact Disc) or a DVD (Digital Versatile Disc). The recording medium may also be realized as a semiconductor recording medium such as a USB (Universal Serial Bus) memory or an SD (Secure Digital) card. The recording medium may also be realized as a magnetic recording medium such as a flexible disk or other recording medium.

[0093] The components in the present disclosure may be combined in any manner. The components in the present disclosure may be realized by software. The components in the present disclosure may be realized by circuits.

[0094] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0095] A part or all of the above-described embodiments can be described as, but not limited to, the following supplementary notes. (Appendix 1) an antenna substrate on which at least one patch antenna, a signal line connected to the patch antenna, and a metal-insulator phase transition element provided on the signal line are arranged; a temperature control substrate including a thin film transistor circuit and having at least one heat generating element disposed thereon, the heat generating element being temperature controlled by the thin film transistor circuit; The planar antenna is configured by bonding the antenna substrate and the temperature control substrate together so that heat from the heat generating element can be conducted to the metal-insulator phase transition element. (Appendix 2) The metal-insulator phase transition element is a phase change switch comprising vanadium dioxide, The heating element is 2. The planar antenna of claim 1, configured to generate heat in response to temperature control of the thin-film transistor circuit to a temperature exceeding the phase transition temperature at which the vanadium dioxide transitions from an insulating phase to a metallic phase. (Appendix 3) A plurality of the patch antennas are arranged in a two-dimensional array, The signal line is a first signal line connected to a signal source via a phase shifter associated with each of the plurality of patch antennas, and a second signal line extending to below the plurality of patch antennas; The second signal line is configured to connect to the patch antenna by electromagnetic coupling; The metal-insulator phase transition element is disposed between the first signal line and the second signal line, 2. A planar antenna according to claim 1, wherein antenna elements including one each of the patch antenna, the metal-insulator phase transition element, and the heat generating element constitute a phased array antenna. (Appendix 4) 4. The planar antenna according to claim 3, wherein a spacer is disposed between the antenna substrate and the temperature control substrate so as to surround the metal-insulator phase transition element and the heat generating element. (Appendix 5) 4. The planar antenna according to claim 3, wherein a thermally conductive sheet is disposed between the metal-insulator phase transition element and the heat generating element. (Appendix 6) a thermally conductive layer is formed between the antenna substrate and the metal-insulator phase transition element; the metal-insulator phase transition element and the heat generating element are arranged in a positional relationship such that they do not overlap each other in a plan view; 6. The planar antenna according to claim 5, wherein a thermal conductor is disposed between the heat generating element and the thermally conductive layer. (Appendix 7) The heating element is formed on the surface of the metal-insulator phase transition element, 4. The planar antenna according to claim 3, which is arranged so as to be connected to wiring constituting the thin film transistor circuit via bumps formed on the surface of the temperature control substrate. (Appendix 8) 2. The planar antenna according to claim 1, wherein the patch antenna and the signal line are connected by electromagnetic coupling. (Appendix 9) The antenna substrate is 9. The planar antenna according to claim 8, further comprising a ground layer having an opening formed below the patch antenna for electromagnetic coupling between the patch antenna and the signal line. (Appendix 10) A planar antenna according to any one of Supplementary Notes 1 to 9; a signal source connected to a metal-insulator phase transition element included in the planar antenna via a signal line; a phase shifter including a phase shift wiring disposed between the metal-insulator phase transition element and the signal source; a matrix circuit in which a plurality of thin film transistors connected to wiring included in the planar antenna are arranged in a two-dimensional array; a drive circuit for driving the thin film transistors included in the matrix circuit; a control circuit that drives the drive circuit in response to a control signal. [Explanation of symbols]

[0096] 1, 2, 3, 4 Planar antenna 10, 20, 30 antenna arrays 11, 21, 41 Antenna board 13, 23, 43 Temperature control board 15, 25 Thermally conductive layer 31 Phase shifter 32 Matrix Circuit 37 Drive circuit 38 Control circuit 39 Signal source 110, 210 First board 120, 220 Second board 121 Alumina substrate 122 Silica layer 123 Dielectric Substrate 124 Silicon substrate 141 Spacer 142 Thermal Conduction Sheet 143 Thermal Conductors 300 Antenna Device 371 First drive circuit 372 Second drive circuit

Claims

1. an antenna substrate on which at least one patch antenna, a signal line connected to the patch antenna, and a metal-insulator phase transition element provided on the signal line are arranged; a temperature control substrate including a thin film transistor circuit and having at least one heat generating element disposed thereon, the heat generating element being temperature controlled by the thin film transistor circuit; The planar antenna is configured by bonding the antenna substrate and the temperature control substrate together so that heat from the heat generating element can be conducted to the metal-insulator phase transition element.

2. The metal-insulator phase transition element is a phase change switch comprising vanadium dioxide, The heating element is 2. The planar antenna according to claim 1, wherein the antenna generates heat in response to temperature control of the thin film transistor circuit up to a temperature exceeding a phase transition temperature at which the vanadium dioxide transitions from an insulating phase to a metallic phase.

3. A plurality of the patch antennas are arranged in a two-dimensional array, The signal line is a first signal line connected to a signal source via a phase shifter associated with each of the plurality of patch antennas; and a second signal line extending to below the plurality of patch antennas, The second signal line is configured to connect to the patch antenna by electromagnetic coupling; The metal-insulator phase transition element is disposed between the first signal line and the second signal line, 2. The planar antenna according to claim 1, wherein antenna elements each including one of the patch antenna, the metal-insulator phase transition element, and the heat generating element constitute a phased array antenna.

4. 4. The planar antenna according to claim 3, wherein a spacer is disposed between the antenna substrate and the temperature control substrate so as to surround the metal-insulator phase transition element and the heat generating element.

5. 4. The planar antenna according to claim 3, wherein a thermally conductive sheet is disposed between the metal-insulator phase transition element and the heat generating element.

6. a thermally conductive layer is formed between the antenna substrate and the metal-insulator phase transition element; the metal-insulator phase transition element and the heat generating element are arranged in a positional relationship such that they do not overlap each other in a plan view; 6. The planar antenna according to claim 5, further comprising a heat conductor disposed between the heat generating element and the heat conducting layer.

7. The heating element is formed on the surface of the metal-insulator phase transition element, 4. The planar antenna according to claim 3, wherein the temperature control substrate is connected to wiring constituting the thin film transistor circuit via bumps formed on the surface of the temperature control substrate.

8. 2. The planar antenna according to claim 1, wherein the patch antenna and the signal line are connected by electromagnetic coupling.

9. The antenna substrate is 9. The planar antenna according to claim 8, further comprising a ground layer formed below the patch antenna, the ground layer having an opening for electromagnetically coupling the patch antenna and the signal line.

10. A planar antenna according to any one of claims 1 to 9; a signal source connected to a metal-insulator phase transition element included in the planar antenna via a signal line; a phase shifter including a phase shift wiring disposed between the metal-insulator phase transition element and the signal source; a matrix circuit in which a plurality of thin film transistors connected to wiring included in the planar antenna are arranged in a two-dimensional array; a drive circuit for driving the thin film transistors included in the matrix circuit; a control circuit that drives the drive circuit in response to a control signal.

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