Phase shifter and antenna device

Abstract

In order to provide a phase shifter or the like that can be stably controlled independent of the environmental temperature, this phase shifter comprises a 90-degree hybrid circuit and a variable-length stub group that includes two variable-length stubs connected to the 90-degree hybrid circuit. The variable-length stubs each comprise: a first switch that is connected to the 90-degree hybrid circuit and includes vanadium dioxide of a first composition that phase transitions in a first phase transition temperature range; a first stub that is connected to the first switch; a second switch that is connected to the first stub and includes vanadium dioxide of a second composition that phase transitions in a second phase transition temperature range higher than the first phase transition temperature range; and a second stub that is connected to the second switch and has an end grounded.

Description

[Technical Field]

[0001] The present disclosure relates to a phase shifter and the like implemented in an antenna device. [Background technology]

[0002] Antenna devices compatible with high-frequency radio waves are being developed for mobile communications beyond the fifth generation. Such antenna devices incorporate a phase shifter in the front stage of the antenna element. By using a phase shifter to change the excitation phase of the antenna element, a desired directional beam can be formed. For example, a switched-line phase shifter can cover a phase shift range of up to 360 degrees, achieving a large scanning angle. However, it is difficult to incorporate such a phase shifter into a small antenna device such as a patch antenna.

[0003] Patent Document 1 discloses a phased array antenna equipped with a flexible variable phase shifter. The phase shifter in Patent Document 1 includes a flexible 90-degree hybrid coupler and a flexible conductive polymer actuator. The phase shifter in Patent Document 1 controls the phase of a high-frequency signal input to the 90-degree hybrid coupler by combining the 90-degree hybrid coupler and the conductive polymer actuator.

[0004] Non-Patent Document 1 reports a phase shifter including a switch that utilizes the metal-insulator phase transition (hereinafter referred to as phase transition) of vanadium dioxide VO2. When the temperature of vanadium dioxide VO2 is increased from room temperature, the electrical resistance of the material decreases rapidly at around 67 degrees Celsius, and the material undergoes a phase transition from an insulator to a metal. The phase shifter in Non-Patent Document 1 uses an electrical trigger to induce a phase transition in vanadium dioxide VO2, generating a phase shift.

[0005] Non-Patent Document 2 reports on a variable integrated passive element using a vanadium dioxide VO2 thin film. Non-Patent Document 2 (page 23, etc.) describes the change in phase transition temperature depending on the dopant added to vanadium dioxide VO2. When chromium Cr, aluminum Al, or germanium Ge is added, the phase transition temperature of vanadium dioxide VO2 increases. On the other hand, when tungsten W, magnesium Mg, iron Fe, molybdenum Mo, fluorine F, or niobium Nb is added, the phase transition temperature of vanadium dioxide VO2 decreases. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-171501 [Non-patent literature]

[0007] [Non-Patent Document 1] EA Casu et al., “Shunt capacitive switches based on VO2 metal insulator transition for RF phase shifter applications,” 2017 47th European Solid-State Device Research Conference (ESSDERC), 2017, pp.232-235. [Non-patent document 2] Li Liangyu. “Experimental Investigation of Integrated Tunable Passive Microwave Devices,” Doctoral dissertation, University of Dayton, 2020, pp.23. Summary of the Invention [Problem to be solved by the invention]

[0008] By combining Patent Document 1 and Non-Patent Documents 1 and 2, a phase shifter including a switch utilizing the phase transition of vanadium dioxide VO2 can be realized. A switch utilizing the phase transition of vanadium dioxide VO2 can control ON / OFF by controlling the temperature between a temperature below the phase transition temperature and a temperature above the phase transition temperature. Such a phase shifter can be miniaturized and therefore incorporated into a small antenna device.

[0009] When a device equipped with a phase shifter containing a switch that utilizes the phase transition of vanadium dioxide (VO2) is placed in an environment close to the phase transition temperature of vanadium dioxide (VO2), the ON / OFF state of the switch becomes unstable. For example, inside a car under the scorching sun of midsummer, the environment temperature may approach the phase transition temperature of vanadium dioxide (VO2). If a cooling mechanism is installed in the device, it is possible to maintain a low temperature inside the device. However, it is difficult to install such a cooling mechanism in a small antenna device. Furthermore, even if a cooling mechanism could be installed in the antenna device, power consumption would increase significantly.

[0010] An object of the present disclosure is to provide a phase shifter or the like that can be stably controlled without depending on the environmental temperature. [Means for solving the problem]

[0011] A phase shifter according to one embodiment of the present disclosure includes a 90-degree hybrid circuit and a variable-length stub group including two variable-length stubs connected to the 90-degree hybrid circuit. The variable-length stubs include a first switch connected to the 90-degree hybrid circuit and including vanadium dioxide of a first composition that undergoes an insulating-metallic phase transition in a first phase transition temperature range, a first stub connected to the first switch, a second switch connected to the first stub and including vanadium dioxide of a second composition that undergoes an insulating-metallic phase transition in a second phase transition temperature range that is higher than the first phase transition temperature range, and a second stub connected to the second switch and having a grounded end. [Effects of the Invention]

[0012] According to the present disclosure, it is possible to provide a phase shifter or the like that can be stably controlled without depending on the environmental temperature. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 is a conceptual diagram illustrating an example of the configuration of a phase shifter according to the first embodiment. [Figure 2] 2 is a conceptual diagram for explaining a 90-degree hybrid circuit included in the phase shifter according to the first embodiment. FIG. [Figure 3] FIG. 2 is a conceptual diagram for explaining a group of variable-length stubs included in the phase shifter according to the first embodiment. [Figure 4] 3 is a conceptual diagram showing an example of the open / closed state of a switch included in the phase shifter according to the first embodiment. FIG. [Figure 5] 3 is a conceptual diagram showing an example of the open / closed state of a switch included in the phase shifter according to the first embodiment. FIG. [Figure 6] FIG. 10 is a conceptual diagram for explaining a group of variable-length stubs included in a phase shifter according to a modified example of the first embodiment. [Figure 7] FIG. 4 is a conceptual diagram showing an example of an open / closed state of a switch included in a phase shifter according to a modified example of the first embodiment. [Figure 8] FIG. 4 is a conceptual diagram showing an example of an open / closed state of a switch included in a phase shifter according to a modified example of the first embodiment. [Figure 9] FIG. 10 is a block diagram showing an example of the configuration of an antenna device according to a second embodiment. [Figure 10] FIG. 10 is a conceptual diagram illustrating an example of the configuration of an antenna device according to a second embodiment. [Figure 11] FIG. 10 is a cross-sectional view of a portion of an antenna device according to a second embodiment. [Figure 12] FIG. 10 is a conceptual diagram of a part of an antenna device according to a second embodiment. [Figure 13] FIG. 10 is a conceptual diagram illustrating an example of the configuration of a phase shifter according to a third embodiment. [Figure 14] FIG. 2 is a block diagram showing an example of a hardware configuration for realizing control and processing according to each embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, the embodiments described below are limited in a manner that is technically preferable for carrying out the present invention, but the scope of the invention is not limited to the following. In all drawings used to describe the following embodiments, the same reference numerals are used for similar parts unless otherwise specified. Furthermore, in the following embodiments, repeated explanations of similar configurations and operations may be omitted.

[0015] (First embodiment) First, a phase shifter according to a first embodiment will be described with reference to the drawings. For example, the phase shifter of this embodiment is mounted in an antenna device including a patch antenna, which is a type of planar antenna. The phase shifter of this embodiment can be applied to transmitting radio waves to be transmitted and receiving radio waves to be received from the outside. For example, the phase shifter of this embodiment can be applied to an antenna device used for transmitting and receiving signals to be transmitted and received in high frequency bands used in mobile communications from fifth generation mobile communications onward. Hereinafter, the electrical length of the signals to be transmitted and received on the board will be represented as λ (λ is a real number).

[0016] (composition) 1 is a conceptual diagram showing an example of the configuration of a phase shifter 10 according to this embodiment. The phase shifter 10 includes a 90-degree hybrid circuit 11, a first switch group 12, a first stub group 13, a second switch group 15, and a second stub group 16. The phase shifter 10 also includes an input terminal T I and the output terminal T where the phase-shifted signal is output. O Each of the first switch group 12 and the second switch group 15 includes two switches SW. The switches SW are phase transition switches that utilize the phase transition between the insulating phase and the metallic phase of vanadium dioxide VO2. The open / closed states of the respective switches SW are individually controlled by a control circuit (not shown). Each of the first stub group 13 and the second stub group 16 includes two stubs ST.

[0017] Vanadium dioxide VO2 exhibits an insulating-metallic phase transition in a temperature range including the phase transition temperature (called the phase transition temperature range). In the temperature range below the phase transition temperature range (low temperature range), vanadium dioxide VO2 has a monoclinic structure (insulating phase). In the temperature range above the phase transition temperature range (high temperature range), vanadium dioxide VO2 has a tetragonal structure (metallic phase). When the temperature is increased from the low temperature range to the high temperature range and exceeds the phase transition temperature range (also called the metallic transition temperature range), vanadium dioxide VO2 undergoes a phase transition from the insulating phase to the metallic phase. On the other hand, when the temperature is decreased from the high temperature range to the low temperature range and falls below the phase transition temperature range (also called the insulating transition temperature range), vanadium dioxide VO2 undergoes a phase transition from the metallic phase to the insulating phase. Because the metallic transition temperature range is usually higher than the insulating transition temperature range, the insulating-metallic phase transition of vanadium dioxide VO2 with temperature changes exhibits hysteresis.

[0018] A plurality of switches SW included in the first switch group 12 and the second switch group 15 and a plurality of stubs ST included in the first stub group 13 and the second stub group 16 form a variable-length stub group 120. The variable-length stub group 120 includes two variable-length stubs. The variable-length stub includes two stubs ST connected in series via a switch SW included in the second switch group 15. The two variable-length stubs are connected to both ends of one of the transmission lines included in the 90-degree hybrid circuit 11. The length of the variable-length stub is controlled according to the open / close state of the SW. Regardless of the open / close state of the SW, the electrical lengths of the two variable-length stubs are the same.

[0019] 2 is a conceptual diagram for explaining the 90-degree hybrid circuit 11. The 90-degree hybrid circuit 11 includes four transmission lines (R1, R2, R3, R4). The electrical lengths of all four transmission lines (R1, R2, R3, R4) are λ / 4 (90 degrees).

[0020] The transmission line R1 has an electrical length of λ / 4. The characteristic impedance of the transmission line R1 is Z0 / √2. A first end of the transmission line R1 is connected to an input port T1. The first end of the transmission line R1 is connected to a first end of a transmission line R2. The second end of the transmission line R1 is connected to a first end of a transmission line R4. The second end of the transmission line R1 is connected to a first switch SW L1 is connected to the first end of the

[0021] The transmission line R2 has an electrical length of λ / 4. The characteristic impedance of the transmission line R2 is Z0. The first end of the transmission line R2 is connected to the input terminal T I The first end of the transmission line R2 is connected to the first end of the transmission line R1. The second end of the transmission line R2 is connected to the output terminal T O Furthermore, the second end of the transmission line R2 is connected to the first end of the transmission line R3.

[0022] The transmission line R3 has an electrical length of λ / 4. The characteristic impedance of the transmission line R2 is Z0 / √2. The first end of the transmission line R3 is connected to the output terminal T O . A first end of the transmission line R3 is connected to a second end of the transmission line R2. A second end of the transmission line R3 is connected to a second end of the transmission line R4. A second end of the transmission line R3 is connected to a first switch SW L2 is connected to the first end of the

[0023] The transmission line R4 has an electrical length of λ / 4. The characteristic impedance of the transmission line R4 is Z0. The first end of the transmission line R4 is connected to the second end of the transmission line R1. The first end of the transmission line R4 is also connected to the first switch SW L1 The second end of the transmission line R4 is connected to the first end of the transmission line R3. The second end of the transmission line R4 is connected to the second end of the first switch SW L2 is connected to the first end of the

[0024] The first switch group 12 includes a first switch SW L1 and the first switch SW L2 Includes the first switch SW L1 and the first switch SW L2 is a phase transition switch that utilizes the phase transition between the insulating phase and the metallic phase of vanadium dioxide (VO2). L1 and the first switch SW L2 is the first phase transition temperature range T L The vanadium dioxide VO2 contains vanadium dioxide of a first composition that undergoes a phase transition from an insulating phase to a metallic phase. The phase transition between the insulating phase and the metallic phase of vanadium dioxide VO2 exhibits hysteresis. Therefore, the metallic transition temperature range in which the phase transition occurs from the insulating phase (low temperature) to the metallic phase (high temperature) is different from the insulating transition temperature range in which the phase transition occurs from the metallic phase (high temperature) to the insulating phase (low temperature). In the following, the metallic transition temperature range and the insulating transition temperature range will not be distinguished from each other and will be referred to as the first phase transition temperature range T L The first phase transition temperature range T L corresponds to a temperature range including the metallic transition temperature range and the insulating transition temperature range.

[0025] For example, the first switch SW L1 and the first switch SW L2 For example, the first switch SW L1 and the first switch SW L2 The vanadium dioxide VO2 contained in the first switch SW L1 and the first switch SW L2 The vanadium dioxide VO2 contained in the material contains additive elements to lower the phase transition temperature. For example, the addition of additive elements such as tungsten (W), magnesium (Mg), iron (Fe), molybdenum (Mo), fluorine (F), and niobium (Nb) lowers the phase transition temperature of vanadium dioxide VO2.

[0026] 1st phase transition temperature range T L At temperatures lower than 1000 K, vanadium dioxide (VO2) is in an insulating phase. Therefore, the first phase transition temperature range T L At temperatures lower than L1 and the first switch SWL2 is OFF. First phase transition temperature region T L At temperatures above 1000 K, vanadium dioxide (VO2) is in the metallic phase. Therefore, the first phase transition temperature range T L At temperatures higher than L1 and the first switch SW L2 is ON. FIG. 1 shows the switches SW included in the first switch group 12 (first switch SW L1 , first switch SW L2 ) is the first phase transition temperature range T L 1, the switch SW included in the first switch group 12 is OFF. In the phase transition between the insulating phase and the metallic phase of vanadium dioxide VO2, the insulating transition temperature range is higher than the metallic transition temperature range. Therefore, when the switch SW is temperature-controlled to a temperature above the metallic transition temperature range, the switch SW switches from OFF (insulating phase) to ON (metallic phase). On the other hand, when the switch SW is temperature-controlled to a temperature below the insulating transition temperature range, the switch SW switches from ON (metallic phase) to OFF (insulating phase).

[0027] First switch SW L1 The first end of the first switch SW is connected to the second end of the transmission line R1 and the first end of the transmission line R4. L1 The second end of the first stub ST included in the first stub group 13 11 The first phase transition temperature range T L When the temperature is controlled to a lower temperature than L1 is OFF. First phase transition temperature region T L When the temperature is controlled to a higher temperature than L1 is ON.

[0028] First switch SW L2 The first end of the first switch SW is connected to the second end of the transmission line R3 and the second end of the transmission line R4. L2 The second end of the first stub ST included in the first stub group 13 12 The first phase transition temperature range T LWhen the temperature is controlled to a lower temperature than L2 is OFF. First phase transition temperature region T L When the temperature is controlled to a higher temperature than L2 is ON.

[0029] The first stub group 13 includes the first stub ST 11 and 1st Stub ST 12 3 is a conceptual diagram for explaining the electrical lengths of the stubs ST included in the first stub group 13 and the second stub group 16. 11 and 1st Stub ST 12 The electrical length of each of the first stubs ST is λ / 8 (45 degrees). 11 and 1st Stub ST 12 The electrical length of is half the electrical length of the four transmission lines (R1, R2, R3, R4) included in the 90-degree hybrid circuit 11.

[0030] 1st Stub Station 11 is a stub with an electrical length of λ / 8. 11 The first end of the first switch SW1 is connected to the first switch SW2 included in the first switch group 12. L1 The first stub ST is connected to the second end of the 11 The second end of the second switch SW H1 The first switch SW L1 is ON and the second switch SW H1 When is OFF, the first stub ST 11 functions as an open stub with an electrical length of λ / 8. L1 is ON and the second switch SW H1 When ON, the first stub ST 11 is the second stub ST included in the second stub group 16. 21 Together with this, it functions as a short stub with an electrical length of λ / 4.

[0031] 1st Stub Station 12 is a stub with an electrical length of λ / 8. 12The first end of the first switch SW1 is connected to the first switch SW2 included in the first switch group 12. L2 The first stub ST is connected to the second end of the 12 The second end of the second switch SW H2 The first switch SW L2 is ON and the second switch SW H2 When is OFF, the first stub ST 12 functions as an open stub with an electrical length of λ / 8. L2 is ON and the second switch SW H2 When ON, the first stub ST 12 is the second stub ST included in the second stub group 16. 22 Together with this, it functions as a short stub with an electrical length of λ / 4.

[0032] The second switch group 15 includes a second switch SW H1 and the second switch SW H2 Second switch SW H1 and the second switch SW H2 is a phase transition switch that utilizes the phase transition between the insulating phase and the metallic phase of vanadium dioxide (VO2). H1 and the second switch SW H2 is the second phase transition temperature range T H The second composition of vanadium dioxide (VO2) undergoes a phase transition from an insulating phase to a metallic phase in the first phase transition temperature range T L Compared with the second phase transition temperature range T H is a high temperature. The phase transition between the insulating phase and the metallic phase of vanadium dioxide VO2 exhibits hysteresis. Therefore, the metallic transition temperature range where the phase transition occurs from the insulating phase (low temperature) to the metallic phase (high temperature) is different from the insulating transition temperature range where the phase transition occurs from the metallic phase (high temperature) to the insulating phase (low temperature). In the following, the metallic transition temperature range and the insulating transition temperature range will not be distinguished, and will be referred to as the second phase transition temperature range T H The second phase transition temperature range T H corresponds to a temperature range including the metallic transition temperature range and the insulating transition temperature range.

[0033] For example, the second switch SW H1 and the second switch SWH2 The vanadium dioxide VO2 contained in the first switch group 12 is doped with an additive element to increase the phase transition temperature. For example, when chromium Cr, aluminum Al, or germanium Ge is added, the phase transition temperature of the vanadium dioxide VO2 increases. L1 and the first switch SW L2 Vanadium dioxide VO2 may contain additive elements that lower the phase transition temperature. In such cases, the first phase transition temperature range T L The second phase transition temperature range T H If is high, the second switch SW H1 and the second switch SW H2 may include vanadium dioxide VO2 with no added elements.

[0034] 2nd phase transition temperature range T H At temperatures lower than 1000 K, vanadium dioxide (VO2) is in an insulating phase. Therefore, the second phase transition temperature range T H At temperatures lower than this, the second switch SW H1 and the second switch SW H2 is OFF. Second phase transition temperature region T H At temperatures above 1000 K, vanadium dioxide (VO2) is in the metallic phase. Therefore, the second phase transition temperature range T H At temperatures higher than H1 and the second switch SW H2 is ON. FIG. 1 shows the switches SW included in the second switch group 15 (second switch SW H1 , second switch SW H2 ) is the second phase transition temperature range T HIn the state of FIG. 1, all the switches SW included in the second switch group 15 are OFF. In the phase transition between the insulating phase and the metallic phase of vanadium dioxide VO2, the insulating transition temperature range is higher than the metallic transition temperature range. Therefore, when the switch SW is temperature-controlled to a temperature above the metallic transition temperature range, the switch SW switches from OFF (insulating phase) to ON (metallic phase). On the other hand, when the switch SW is temperature-controlled to a temperature below the insulating transition temperature range, the switch SW switches from ON (metallic phase) to OFF (insulating phase).

[0035] Second switch SW H1 The first end of the first stub ST included in the first stub group 13 11 The second switch SW H1 The second end of the second stub ST included in the second stub group 16 21 The second phase transition temperature range T H When the temperature is controlled to a lower temperature than H1 is OFF. Second phase transition temperature region T H When the temperature is controlled to a higher temperature than H1 is ON.

[0036] Second switch SW H2 The first end of the first stub ST included in the first stub group 13 12 The second switch SW H2 The second end of the second stub ST included in the second stub group 16 22 The second phase transition temperature range T H At temperatures lower than H2 is OFF. Second phase transition temperature region T H At temperatures higher than H2 is ON.

[0037] The second stub group 16 includes the second stub ST 21 and the second stub ST 22 As shown in Figure 3, the second stub ST 21and the second stub ST 22 The electrical length of each of the second stubs ST is λ / 8 (45 degrees). 21 and the second stub ST 22 The electrical length of the first stub ST included in the first stub group 13 is 11 and 1st Stub ST 12 The electrical length is the same as that of

[0038] 2nd Stub ST 21 is a stub with an electrical length of λ / 8. 21 The first end of the second switch SW1 is connected to the second switch SW2 included in the second switch group 15. H1 The second stub ST is connected to the second end of the 21 The second end (also called the terminal end) of the second switch SW is grounded. H1 When is OFF, the second stub ST 21 does not function as a stub. L1 is ON and the second switch SW H1 When ON, the second stub ST 21 is the first stub ST included in the first stub group 13. 11 Together with this, it functions as a short stub with an electrical length of λ / 4.

[0039] 2nd Stub ST 22 is a stub with an electrical length of λ / 8. 22 The first end of the second switch SW1 is connected to the second switch SW2 included in the second switch group 15. H1 The second stub ST is connected to the second end of the 22 The second end (also called the terminal end) of the second switch SW is grounded. H2 When is OFF, the second stub ST 22 does not function as a stub. L2 is ON and the second switch SW H2 When ON, the second stub ST 22 is the first stub ST included in the first stub group 13. 12 Together with this, it functions as a short stub with an electrical length of λ / 4.

[0040] Figure 4 shows the temperature distribution of the first phase transition region T L and the second phase transition temperature region T H 1 is a conceptual diagram showing the connection state of the first switch group 12 and the second switch group 15 when the environmental temperature T is in a temperature range (first temperature range) between L In the first temperature range, the first switch SW L1 and the first switch SW L2 On the other hand, in the first temperature range, the second switch SW H1 and the second switch SW H2 In the first temperature range, the second switch SW H1 and the second switch SW H2 If is OFF, the first stub ST included in the first stub group 13 11 and 1st Stub ST 12 However, it functions as an open stub with an electrical length of λ / 8.

[0041] Figure 5 shows the temperature distribution of the second phase transition region T H 1 is a conceptual diagram showing the connection state of the first switch group 12 and the second switch group 15 in the above temperature range (second temperature range). In the second temperature range, the first switch SW L1 and the first switch SW L2 is always ON and cannot be controlled. In the second temperature range, the second switch SW H1 and the second switch SW H2 In the second temperature range, the first stub ST included in the first stub group 13 is always ON and cannot be controlled. 11 and 1st Stub ST 12 and the second stub ST included in the second stub group 16 21 and the second stub ST 22 It functions as a short stub with an electrical length of λ / 4.

[0042] The environmental temperature T is the first phase transition temperature range T LWhen the temperature is lower than this (normal temperature range), the first switch SW L1 , first switch SW L2 , second switch SW H1 , and the second switch SW H2 are all controllable.

[0043] (Variation) Next, a phase shifter according to a modified example of this embodiment will be described with reference to the drawings. In this modified example, the electrical lengths of the stubs included in the first stub group 13 and the second stub group are variable. FIGS. 6 to 8 are conceptual diagrams for explaining the phase shifter according to the modified example. The phase shifter according to the modified example includes a 90-degree hybrid circuit 11 and a stub group 120-1. FIGS. 6 to 8 show an arrangement of the phase shifter 10 rotated 90 degrees counterclockwise from the arrangement shown in FIG. 1. Therefore, the 90-degree hybrid circuit 11 is rotated 90 degrees counterclockwise from the state shown in FIG. 1. The 90-degree hybrid circuit 11 has the same configuration as that shown in FIG. 1, so a detailed description thereof will be omitted.

[0044] The stub group 120-1 includes a first switch group 12, a first stub group 13-1, a second switch group 15, and a second stub group 16-1. The stub group 120-1 includes two variable-length stubs. The two variable-length stubs have the same configuration.

[0045] The first switch group 12 has the same configuration as that included in the phase shifter 10 (FIG. 1). The first switch group 12 includes two first switches SW L Includes the first switch SW L is a phase transition switch that utilizes the insulator-metal phase transition of vanadium dioxide (VO2). L is the first phase transition temperature range T L It contains vanadium dioxide VO2, which undergoes a phase transition from an insulating phase to a metallic phase in the first phase transition temperature region T L At temperatures lower than 1000 K, vanadium dioxide (VO2) is in an insulating phase. Therefore, the first phase transition temperature range T L When the temperature is controlled to a lower temperature than L is OFF. First phase transition temperature region TL At temperatures above 1000 K, vanadium dioxide (VO2) is in the metallic phase. Therefore, the first phase transition temperature range T L When the temperature is controlled to a higher temperature than L 6 shows all the first switches SW included in the first switch group 12. L is the first phase transition temperature region T L The temperature is controlled to a lower value than that of all the first switches SW L is OFF.

[0046] The first stub group 13-1 includes the first stub ST 1a , 1st Stub ST 1b , 1st Stub ST 1c , first switch SW L11 , and the first switch SW L12 Includes two sets of the first stub ST 1a , first switch SW L11 , 1st Stub ST 1b , first switch SW L12 , and the first stub ST 1c constitutes one variable-length stub. The first stub ST 1a The electrical length of a First stub ST 1b The electrical length of b First stub ST 1c The electrical length of c First stub ST 1a , 1st Stub ST 1b , and the first stub ST 1c The electrical length of the first switch SW is set according to the wavelength of the radio wave to be transmitted and received. L11 and the first switch SW L12 is the phase transition temperature in the first phase transition temperature region T L It is a phase change switch containing vanadium dioxide VO2.

[0047] 1st Stub Station 1a The first end of the first switch SW1 is connected to the first switch SW2 included in the first switch group 12. L The first stub ST is connected to the second end of the 1a The second end of the L11The first switch SW L11 The second end of the first stub ST 1b The first stub ST is connected to the first end of the 1b The second end of the L12 The first switch SW L12 The second end of the first stub ST 1c The first stub ST is connected to the first end of the 1c The second end of the second switch SW1 is connected to the second switch SW2 included in the second switch group 15. H is connected to the first end of the

[0048] For example, the first switch SW L11 and the first switch SW L12 When the temperatures of the first stub group 13-1 and the second stub group 13-2 can be controlled individually, the electrical lengths of the two variable-length stubs in the first stub group 13-1 are a , L a +L b , and L a +L b +L c The first switch SW L11 When is OFF, the electrical length of the variable length stub is L a The first switch SW L11 is ON, first switch SW L12 When is OFF, the electrical length of the variable length stub is L a +L b The first switch SW L11 and the first switch SW L12 When is ON, the electrical length of the variable length stub is L a +L b +L c is.

[0049] The second switch group 15 has the same configuration as that included in the phase shifter 10 (FIG. 1). The second switch group 15 includes two second switches SW H Second switch SW H is a phase transition switch that utilizes the insulator-metal phase transition of vanadium dioxide (VO2). H is the first phase transition temperature range T L The second phase transition temperature range TH The second phase transition temperature range T H At temperatures lower than this, the second switch SW H The vanadium dioxide VO2 contained in the material is an insulating phase. Therefore, the second phase transition temperature range T H When the temperature is controlled to a lower temperature than H is OFF. Second phase transition temperature region T H At temperatures higher than H The vanadium dioxide VO2 contained in the alloy is in a metallic phase. Therefore, the second phase transition temperature range T H When the temperature is controlled to a higher temperature than H 6 shows all the second switches SW included in the second switch group 15. H is the second phase transition temperature region T H In the state shown in FIG. 6, all the second switches SW H is OFF.

[0050] The second stub group 16-1 includes the second stub ST 2a , 2nd stub ST 2b , 2nd stub ST 2c , second switch SW H21 , second switch SW H22 , second switch SW H23 , and the second switch SW H24 Includes two sets of 1 second stub ST 2a , 2nd stub ST 2b , 2nd stub ST 2c , second switch SW H21 , second switch SW H22 , second switch SW H23 , and the second switch SW H24 constitutes one variable-length stub. The second stub ST 2a The electrical length of a Second stub ST 2b The electrical length of b Second stub ST 2c The electrical length of c Second stub ST2a , 2nd stub ST 2b , and the second stub ST 2c The electrical length of the second switch SW is set according to the wavelength of the radio wave to be transmitted and received. H21 , second switch SW H22 , second switch SW H23 , and the second switch SW H24 is the phase transition temperature in the second phase transition temperature region T H It is a phase change switch containing vanadium dioxide VO2.

[0051] 2nd Stub ST 2a The first end of the second switch SW1 is connected to the second switch SW2 included in the second switch group 15. H The second stub ST is connected to the second end of the 2a The second end of the H21 and the second switch SW H23 The second switch SW H21 The second end of the 2b The second switch SW H23 The second end of the second stub ST is grounded. 2b The second end of the H22 and the second switch SW H24 The second switch SW H22 The second end of the 2c is connected to the first end of the 2 Switch L24 The second end of the second stub ST is grounded. 2c The second end is grounded.

[0052] For example, the second switch SW H21 , second switch SW H22 , second switch SW H23 , and the second switch SW H24 When configured in this manner, the electrical lengths of the two variable-length stubs included in the second stub group 16-1 are a , L a +L b , and L a +L b+L c The second switch SW H21 When is OFF, the electrical length of the variable length stub is L a The second switch SW H21 is ON, second switch SW H22 When is OFF, the electrical length of the variable length stub is L a +L b The second switch SW H21 and the second switch SW H22 When is ON, the electrical length of the variable length stub is L a +L b +L c is.

[0053] The two variable-length stubs included in the second stub group 16-1 are connected to the second switch SW H23 and the second switch SW H24 The second switch SW acts as an open stub or a short stub depending on the ON / OFF control of the H21 and the second switch SW H23 When is OFF, the two variable length stubs have an electrical length of L a The second switch SW H21 is OFF and the second switch SW H23 When is ON, the two variable-length stubs have an electrical length of L a The second switch SW H21 is ON, second switch SW H22 is OFF and the second switch SW H23 When is OFF, the two variable length stubs have an electrical length of L a +L b The second switch SW H21 is ON, second switch SW H22 is OFF and the second switch SW H23 When is ON, the two variable-length stubs have an electrical length of L a +L b The second switch SW H21 is ON, second switch SW H22 is ON, second switch SW H23is OFF and the second switch SW H24 When is OFF, the two variable length stubs have an electrical length of L a +L b +L c It acts as a short stub.

[0054] 7 is a conceptual diagram showing an example of a connection state of a plurality of switches SW included in the stub group 120-1. In the connection state of FIG. 7, the first switch SW included in the first switch group 12 L are all ON. That is, the first stub ST included in the first stub group 13-1 1a , 1st Stub ST 1b , and the first stub ST 1c The second switch SW included in the second switch group 15 is ON. H are all OFF. That is, the second switch SW H21 , second switch SW H22 , second switch SW H23 , and the second switch SW H24 In the example of FIG. 7, the first stub ST included in the first stub group 13-1 is OFF. 1a , 1st Stub ST 1b , and the first stub ST 1c is the electrical length L a +L b +L c It acts as an open stub for

[0055] 8 is a conceptual diagram showing another example of a connection state of a plurality of switches SW included in the stub group 120-1. In the connection state of FIG. 8, the first switch SW included in the first switch group 12 L are all ON. That is, the first stub ST included in the first stub group 13-1 1a , 1st Stub ST 1b , and the first stub ST 1c The second switch SW included in the second switch group 15 is ON. H In the example of FIG. 8, the second switch SW H21 and the second switch SW H24is ON, and the second switch SW H22 and the second switch SW H23 In the example of FIG. 8, the first stub ST 1a , 1st Stub ST 1b , 1st Stub ST 1c , 2nd stub ST 2a , and the second stub ST 2b The electrical length is 2L a +2L b +L c It acts as a short stub.

[0056] As described above, the phase shifter of this embodiment includes a 90-degree hybrid circuit and a group of variable-length stubs. The group of variable-length stubs includes two variable-length stubs connected to the 90-degree hybrid circuit. The variable-length stubs include a first switch, a first stub, a second switch, and a second stub. The first switch is connected to the 90-degree hybrid circuit and includes vanadium dioxide of a first composition that undergoes a phase transition in a first phase transition temperature range. The first stub is connected to the first switch. The second switch is connected to the first stub and includes vanadium dioxide of a second composition that undergoes a phase transition in a second phase transition temperature range that is higher than the first phase transition temperature range. The second stub is connected to the second switch and has one end grounded.

[0057] The phase shifter of this embodiment functions as an open stub when the first switch is ON and the second switch is OFF. Furthermore, the phase shifter of this embodiment functions as a short stub when the first switch is ON and the second switch is ON. The phase shifter of this embodiment can control the second switch even when the ambient temperature exceeds the first phase transition temperature range. Therefore, this embodiment provides a phase shifter that can be stably controlled without depending on the ambient temperature. For example, even if all switches are second switches, the phase shifter can operate stably without depending on the ambient temperature. However, in such a configuration, even if the ambient temperature is in the normal temperature range below the first phase transition temperature range, the second switch needs to be temperature-controlled to the higher second phase transition temperature. With the configuration of this embodiment, the first switch can be temperature-controlled at the lower first phase transition temperature when the ambient temperature is in the normal temperature range. This reduces power consumption compared to a phase shifter in which all switches are second switches that operate at a high temperature.

[0058] In one aspect of this embodiment, the variable-length stub group includes a first switch group, a first stub group, a second switch group, and a second stub group. The first switch group is made up of two first switches. The first stub group is made up of two first stubs. The second switch group is made up of two second switches. The second stub group is made up of two second stubs. According to this aspect, by controlling the switches included in the first switch group and the second switch group separately, it is possible to provide a phase shifter that can be stably controlled without depending on the ambient temperature.

[0059] In one aspect of this embodiment, the 90-degree hybrid circuit is composed of four transmission lines of the same electrical length. The electrical lengths of the first stub and the second stub are half the electrical length of the transmission lines. According to this aspect, the signal can be shifted to a desired phase by adjusting the characteristic impedances of the four transmission lines, the first stub, and the second stub.

[0060] The phase shifter according to one aspect of the present embodiment includes a control circuit that controls the temperatures of two first switches included in the first switch group and two second switches included in the second switch group. The control circuit may be disposed in an antenna device in which the phase shifter is implemented. According to this aspect, the ON / OFF of the first switches and the second switches can be controlled by controlling the temperatures of the first switches and the second switches using the control circuit.

[0061] In one aspect of the present embodiment, the control circuit individually controls the temperature of at least one of the two first switches included in the first switch group and the two second switches included in the second switch group. According to this aspect, by individually controlling the temperatures of the first switches and the second switches, it is possible to individually control the ON / OFF of the first switches and the second switches.

[0062] In one aspect of the present embodiment, the control circuit collectively controls the temperatures of at least two of the two first switches included in the first switch group and the two second switches included in the second switch group. According to this aspect, collectively controlling the temperatures of at least two of the multiple first switches and second switches allows collectively controlling the ON / OFF of at least two first switches and second switches.

[0063] In one aspect of this embodiment, the first stub group includes a plurality of first stubs connected in series by at least one first switch, and the second stub group includes a plurality of second stubs connected in series by at least one second switch. According to this aspect, the electrical lengths of the first stubs and the second stubs are variable.

[0064] (Second embodiment) Next, an antenna device according to a second embodiment will be described with reference to the drawings. The antenna device of this embodiment is an antenna device including the phase shifter according to the first embodiment. The following configuration is an example and does not limit the structure of an antenna device incorporating a phase shifter of the present disclosure.

[0065] (composition) 9 is a block diagram showing an example of the configuration of the antenna device 2. The antenna device 2 includes a phase shifter 20, a patch antenna array 21, a matrix circuit 22, a drive circuit 23, a control circuit 25, a signal source 26, and an amplifier circuit 27. In this embodiment, the phase shifter 20 corresponds to the phase shifter 10 of the first embodiment.

[0066] 10 is a conceptual diagram showing an example of the appearance of the antenna device 2. The antenna device 2 is formed on a first substrate 211 and a second substrate 212. The antenna device 2 has a structure in which the first substrate 211 and the second substrate 212 are stacked. For example, an insulating layer (not shown) is sandwiched between the first substrate 211 and the second substrate 212.

[0067] The first substrate 211 includes a transmission surface for transmitting radio waves to be transmitted. A patch antenna array 21 is disposed on the upper surface (first surface) of the first substrate 211. The patch antenna array 21 includes a plurality of patch antennas 200 arranged in a lattice pattern. The plurality of patch antennas 200 are arranged in a two-dimensional array. In the example of FIG. 10, the plurality of patch antennas 200 are arranged along the X and Y directions. The plurality of patch antennas 200 are arranged in a phased array. For example, the material of the first substrate 211 is a material used for a silicon substrate or glass. For example, the material of the first substrate 211 may be an insulating film such as an oxide film or a nitride film. There are no limitations on the material of the first substrate 211 as long as it is possible to transmit radio waves to be transmitted.

[0068] The patch antenna 200 is a plate-shaped radiating element. In the example of FIG. 10 , the patch antenna 200 has a rectangular shape. The shape of the patch antenna 200 is not limited to a rectangular shape, but may be a circular shape or other shapes. The patch antenna 200 is an open-type resonator. The patch antenna 200 resonates at a frequency equal to an integral multiple of half the wavelength of the length of the patch antenna 200. The size of the patch antenna 200 is set according to the wavelength of the radio waves to be transmitted. To avoid a decrease in the Q value due to radio wave radiation and enable the patch antenna 200 to function as a resonator, a high-dielectric layer having a high dielectric constant may be interposed between the first substrate 211 and the second substrate 212. When a high-dielectric layer is interposed between the first substrate 211 and the second substrate 212, the thickness of the high-dielectric layer and the width of the patch antenna 200 should be sufficiently small compared to the wavelength of the radio waves to be transmitted.

[0069] A first driving circuit 231 and a second driving circuit 232 are mounted on the first substrate 211. The first driving circuit 231 and the second driving circuit 232 constitute the driving circuit 23. The first driving circuit 231 and the second driving circuit 232 drive the TFTs in accordance with the control of the control circuit 25. The driving circuit 23 individually drives the multiple TFTs included in the matrix circuit 22. The first driving circuit 231 is a circuit for performing addressing in the X direction. The second driving circuit 232 is a circuit for performing addressing in the Y direction. For example, the first driving circuit 231 and the second driving circuit 232 are formed on the upper surface (first surface) of the first substrate 211. The first driving circuit 231 and the second driving circuit 232 may also be formed inside the first substrate 211.

[0070] Fig. 11 is a partial cross-sectional view showing a cross section of a portion including the patch antenna 200. Fig. 11 is a partial cross-sectional view taken along the transmission line from the 90-degree hybrid circuit included in the phase shifter to the variable-length stub. Fig. 11 shows a portion associated with one of the multiple patch antennas 200 included in the patch antenna array 21.

[0071] A ground layer GND is formed on the lower surface (second surface) opposite the first surface of the first substrate 211. An opening is formed in the ground layer GND below the patch antenna 200. A via V1 is disposed inside the opening. The via V1 is made of a conductive material. The patch antenna 200 is electrically connected to the transmission line R of the phase shifter 20 disposed on the upper surface of the second substrate 212 through the via V1 disposed inside the opening.

[0072] The second substrate 212 corresponds to the backplane of a liquid crystal display. For example, the material of the second substrate 212 is a material used for a silicon substrate or glass. The second substrate 212 may be made of a material other than silicon or glass, as long as it is capable of transmitting the radio waves to be transmitted. There are no limitations on the material of the second substrate 212, as long as it is capable of transmitting the radio waves to be transmitted.

[0073] A matrix circuit 22 is formed on the second substrate 212. The matrix circuit 22 has a structure in which a plurality of thin film transistors (TFTs) are arranged in a two-dimensional array. The matrix circuit 22 has a configuration in which a plurality of TFTs are arranged in a two-dimensional array. The matrix circuit 22 is formed on the upper surface of the second substrate 212 using a TFT process technology. For example, polysilicon (also called low-temperature polysilicon) manufactured at a low temperature using an excimer laser crystallization method or the like can be used for the TFT. Each of the plurality of TFTs included in the matrix circuit 22 corresponds to one of the plurality of patch antennas 200 included in the patch antenna array 21. For example, the TFT includes a semiconductor layer such as amorphous silicon or polysilicon.

[0074] A signal layer including the phase shifter 20 is formed above the matrix circuit 22. On the signal layer, the transmission lines included in the phase shifter 20, a switch group including a plurality of switching elements, and signal lines connecting the phase shift wiring and the switch group are formed. The phase shifter 20 has the configuration of the first embodiment. A phase shifter 20 is arranged for each patch antenna 200. A single antenna unit is configured for each patch antenna 200. The function of the phase shifter 20 is realized for each antenna unit. The phase shifter 20 may be arranged between the patch antennas 200 arranged on the upper surface of the first substrate 211.

[0075] 11, the phase shifter 20 corresponding to the patch antenna 200 is electrically connected to the patch antenna 200 through a via V1 that penetrates the first substrate 211. The upper part of the via V1 is connected to a feed point P of the patch antenna 200. The lower part of the via V1 is connected to a first end (left end) of a transmission line R included in the 90-degree hybrid circuit. The second end (right end) of the transmission line is connected to a first switch SW L The first switch SW L The second end (right end) of the first stub ST1 is connected to the first end (left end) of the first switch SW2. H The second switch SW H The second end (right end) of the contact layer C is connected to the ground layer GND through the contact layer C and the via V2.

[0076] In Figure 11, the first switch SW L and the second switch SW H Heating wire (H L , H H ) indicates the heating wire H L is the first switch SW L It is used to control the temperature of the thin film of vanadium dioxide (VO2) contained in the heater. H is the second switch SW H It is used to control the temperature of the thin film of vanadium dioxide (VO2) contained in the L , H H) is realized by alloys whose main components are nickel (Ni) and chromium (Cr). L , H H ) may be realized by an alloy mainly composed of chromium Cr, iron Fe, and aluminum Al. L , H H For example, the first switch SW 1 may be made of a material such that its ON / OFF state is controlled by voltage control or current control. L and the second switch SW H may be configured.

[0077] Fig. 12 is a conceptual diagram for explaining a configuration example of a switch SW configured with a switching element including a thin film of vanadium dioxide VO2. Although Fig. 12 shows only one of two variable-length stubs included in a variable-length stub group, the switches SW included in the two variable-length stubs in the same variable-length stub group are also temperature-controlled. Fig. 12 shows the first switch SW L TFT for controlling L and the second switch SW H TFT for controlling H TFT L and TFT H are included in the matrix circuit 22. The matrix circuit 22 includes a TFT L and TFT H Other TFTs may also be included.

[0078] In the example of FIG. 12, a first switch SW L The transmission line R and the first stub ST1 are connected to the first switch SW L The first switch SW L Heating wire H L are thermally connected. Heating wire H L The first end of the power line L PL Connected to the heating wire H L The second end of the TFT L It is connected to the drain d of the TFT. L The source s of the TFT is connected to the ground line G.L The gate of the control line g L A second switch SW H The first stub ST1 and the second stub ST2 are connected to the second switch SW H The second switch SW H Heating wire H H are thermally connected. Heating wire H H The first end of the power line L PH Connected to the heating wire H H The second end of the TFT H It is connected to the drain d of the TFT. H The source s of the TFT is connected to the ground line G. H The gate of the control line g H is connected to.

[0079] TFT L The gate of the control line g L The voltage exceeding the gate voltage is connected to the control line g L When applied to the TFT L transitions to ON, and conduction occurs between the drain and source. As a result, the power supply line L PL Through the heating wire H L Current flows into the heating wire H L The temperature of the heating wire H rises. L The temperature of the power line L PL The amount of current flowing through the TFT H The gate of the control line g H The voltage exceeding the gate voltage is connected to the control line g H When applied to the TFT H transitions to ON, and conduction occurs between the drain and source. As a result, the power supply line L PH Through the heating wire H H Current flows into the heating wire H H The temperature of the heating wire H rises. H The temperature of the power line L PH For example, the amount of current flowing through a TFT L and TFT HA common control line may be connected to the gates of the TFTs. L and TFT H You can control the ON / OFF of all at once.

[0080] heating wire H L The first switch SW L The temperature in the first phase transition temperature region T L When the voltage exceeds the first switch SW L The first switch SW L When the power supply voltage Vcc is turned ON, the transmission line R and the first stub ST1 are electrically connected. H The second switch SW H The temperature in the second phase transition temperature region T H When the voltage exceeds the second switch SW H The second switch SW H When transitions to ON, the transmission line R, the first stub ST1, and the second stub ST2 are electrically connected.

[0081] The control circuit 25 drives the drive circuit 23 in response to an external control signal. The control circuit 25 drives the drive circuit 23 using an active matrix drive system. The control circuit 25 also outputs the external control signal to the signal source 26. The control circuit 25 also outputs a control signal to the signal source 26 for transmitting a signal to be transmitted to a communication target. For example, the control circuit 25 is implemented by a microcomputer (also called a microcomputer) or a microcontroller. The control circuit 25 also uses the drive circuit 23 to control the switch SW, which is configured as a switching element including a thin film of vanadium dioxide (VO2). The control circuit 25 controls the ON / OFF of the switch SW by controlling the current / voltage applied to a control line in response to the external control signal. For example, a dedicated circuit for controlling the ON / OFF of the switch SW may be added to the antenna device 2.

[0082] For example, the control circuit 25 includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), flash memory, etc. The control circuit 25 executes control and processing according to a pre-stored program. The control circuit 25 executes control and processing according to the program in accordance with a pre-set schedule, timing, instructions included in an external control signal, etc.

[0083] The signal source 26 is connected to the control circuit 25 and the amplifier circuit 27. The signal source 26 receives a control signal from the control circuit 25. 26 generates a signal to be transmitted from the patch antenna array 21 in response to a control signal. 26 The signal source 26 generates a signal in the high frequency band used in mobile communications. The signal source 26 outputs the generated signal to the amplifier circuit 27.

[0084] The amplifier circuit 27 is connected to the amplifier circuit 27 and the phase shifter 20. The amplifier circuit 27 receives the signal generated by the signal source 26. The amplifier circuit 27 amplifies the received signal. The amplifier circuit 27 outputs the amplified signal to the input terminal of the phase shifter 20.

[0085] The signal that reaches the input end of phase shifter 20 is phase-shifted by an amount that depends on the line length set in phase shifter 20 and the dielectric constant of the substrates (first substrate 211 and second substrate 212). The phase-shifted signal propagates to patch antenna 200 through via V1. The signal that propagates to patch antenna 200 is transmitted from patch antenna 200 as a radio wave to be transmitted. The radio wave transmitted from patch antenna 200 is based on a signal output from signal source 26 in response to a control signal output from control circuit 25. There are no particular limitations on the information contained in the signal.

[0086] For example, an electromagnetic interference reduction structure may be formed between adjacent wiring such as transmission lines. The electromagnetic interference reduction structure is composed of a plurality of vias penetrating the second substrate 212. The plurality of vias penetrate the second substrate 212 from the upper surface on which the transmission lines are formed to the ground layer GND on the lower surface. For example, a conductive portion is formed inside the vias and around the opening. For example, the conductive portion of the via is plated with a conductive material. The conductive portion of the via electrically connects the upper surface on which the transmission lines are formed to the ground layer GND on the lower surface. The electromagnetic interference reduction structure suppresses electromagnetic interference between adjacently arranged transmission lines.

[0087] For example, a dummy element (not shown) containing vanadium dioxide (VO2) may be disposed around the phase shifter formed on the second substrate 212. To achieve a phase transition at a standard phase transition temperature (around 67°C), it is preferable that no additive elements be added to the dummy element. The phase transition temperature of the vanadium dioxide (VO2) contained in the dummy element corresponds to a temperature range (phase transition temperature range) including the insulating transition temperature and the metallic transition temperature. For example, the control circuit 25 calculates the temperature around the dummy element by measuring the electrical resistance of the dummy element. The control circuit 25 can measure the temperature according to changes in the electrical resistance of the dummy element. If the phase transition temperature is known, the vanadium dioxide (VO2) contained in the dummy element may contain an additive element. Alternatively, if the temperature around the phase shifter can be measured, the dummy element may be disposed on the first substrate 211.

[0088] For example, if multiple dummy elements are arranged on the first substrate 211 or the second substrate 212, control can be achieved according to the temperature and temperature distribution around the phase shifter 20. If an abnormality is detected in the measured temperature or temperature distribution, the control circuit 25 can control the two first switches included in the first switch group and the two second switches included in the second switch group. With this control, even if the substrate temperature becomes abnormally high and switching becomes unstable, the phase shifter of the antenna device 2 can be controlled, thereby preventing malfunction of the antenna device 2.

[0089] As described above, the antenna device according to this embodiment has an antenna unit including the phase shifter according to the first embodiment and a patch antenna arranged above the phase shifter. According to this embodiment, it is possible to provide an antenna device including a phase shifter that can be stably controlled without depending on the ambient temperature.

[0090] The antenna device according to one aspect of the present embodiment has a patch antenna array in which a plurality of antenna units are arranged in an array. The antenna device according to this aspect includes a patch array antenna composed of a plurality of patch antennas whose sizes correspond to the wavelengths of signals to be transmitted and received. The antenna device according to this aspect allows for the configuration of a patch array antenna whose directivity can be controlled.

[0091] An antenna device according to one aspect of this embodiment includes at least one dummy element containing vanadium dioxide that undergoes a phase transition at a known phase transition temperature. The control circuit measures the temperature according to changes in the electrical resistance of the dummy element. If an abnormality is detected in the measured temperature, the control circuit controls two first switches included in the first switch group and two second switches included in the second switch group. According to this aspect, by controlling the switches included in the first switch group and the second switch group according to the temperature measured using the dummy element, malfunction of the antenna device can be prevented.

[0092] (Third embodiment) Next, a phase shifter according to a third embodiment will be described with reference to the drawings. The phase shifter of this embodiment has a simplified configuration of the phase shifters according to the first and second embodiments. Fig. 13 is a conceptual diagram showing an example of the configuration of a phase shifter 30 according to this embodiment. The phase shifter 30 includes a 90-degree hybrid circuit 31 and a variable-length stub group 320.

[0093] The 90-degree hybrid circuit 31 includes four transmission lines (R1, R2, R3, R4). The variable-length stub group 320 includes two variable-length stubs connected to the 90-degree hybrid circuit 31. In the example of FIG. 13, one of the two variable-length stubs is connected to the other end of the transmission line R1 and one end of the transmission line R4. The other of the two variable-length stubs is connected to the other end of the transmission line R3 and the other end of the transmission line R4. Each variable-length stub is connected to a first switch SW L , first stub ST1, second switch SW H , and a second stub ST2. The first switch SW L is connected to the 90-degree hybrid circuit and contains vanadium dioxide of a first composition that undergoes a phase transition between an insulating phase and a metallic phase in a first phase transition temperature range. The first stub ST1 is connected to the first switch SW L The second switch SW H is connected to the first stub ST1 and contains vanadium dioxide of a second composition that undergoes a phase transition between an insulating phase and a metallic phase in a second phase transition temperature range that is higher than the first phase transition temperature range. H is connected to.

[0094] The phase shifter of this embodiment functions as an open stub when the first switch is ON and the second switch is OFF. Also, the phase shifter of this embodiment functions as a short stub when the first switch is ON and the second switch is ON. When the ambient temperature rises suddenly, the phase shifter of this embodiment functions as a short stub as the second switch transitions to ON. Therefore, according to this embodiment, a phase shifter that can be stably controlled without depending on the ambient temperature can be provided.

[0095] (Hardware) Here, a hardware configuration for executing control and processing according to each embodiment of the present disclosure will be described using an information processing device 90 (computer) in Fig. 14 as an example. Note that the information processing device 90 in Fig. 14 is an example configuration for executing control and processing according to each embodiment, and does not limit the scope of the present disclosure.

[0096] As shown in Fig. 14, an information processing device 90 includes a processor 91, a main storage device 92, an auxiliary storage device 93, an input / output interface 95, and a communication interface 96. In Fig. 14, interface is abbreviated as I / F (Interface). The processor 91, the main storage device 92, the auxiliary storage device 93, the input / output interface 95, and the 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, the main storage device 92, the auxiliary storage device 93, and the input / output interface 95 are also connected to a network such as the Internet or an intranet via the communication interface 96.

[0097] The processor 91 loads a program (instructions) stored in an auxiliary storage device 93 or the like onto the main storage device 92. For example, the program is a software program for executing the control and processing of each embodiment. The processor 91 executes the program loaded onto the main storage device 92. The processor 91 executes the program to execute the control and processing of each embodiment.

[0098] The main memory device 92 has an area in which a program is loaded. The processor 91 loads a program stored in the auxiliary memory device 93 or the like into the main memory device 92. The main memory device 92 is realized by a volatile memory such as a DRAM (Dynamic Random Access Memory). Alternatively, a non-volatile memory such as an MRAM (Magneto-resistive Random Access Memory) may be configured / added to the main memory device 92.

[0099] The auxiliary storage device 93 stores various data such as programs. The auxiliary storage device 93 is realized by a local disk such as a hard disk or flash memory. Note that it is also possible to configure the main storage device 92 to store various data, thereby omitting the auxiliary storage device 93.

[0100] 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 and the communication interface 96 may be a common interface for connecting to external devices.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] The above is an example of a hardware configuration for enabling control and processing according to each embodiment of the present invention. The hardware configuration in Fig. 14 is an example of a hardware configuration for executing control and processing according to each embodiment, and does not limit the scope of the present invention. A program that causes a computer to execute control and processing according to each embodiment is also included in the scope of the present invention.

[0105] The scope of the present invention also includes a program recording medium on which the program according to each embodiment is recorded. The recording medium can be realized, for example, 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. When a program executed by a processor is recorded on a recording medium, the recording medium corresponds to a program recording medium.

[0106] The components of each embodiment may be combined in any manner, may be realized by software, or may be realized by a circuit.

[0107] Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention. [Explanation of symbols]

[0108] 2 Antenna device 10 phase shifter 11 90-degree hybrid circuit 12 First switch group 13 First stub group 15 Second switch group 16 Second stub group 21 Patch Antenna Array 22 Matrix Circuit 23 Drive circuit 25 Control circuit 120 Variable-length stubs 211 First board 212 Second board 231 First drive circuit 232 Second drive circuit

Claims

1. A 90-degree hybrid circuit; a variable-length stub group including two variable-length stubs connected to the 90-degree hybrid circuit; The variable length stub is a first switch connected to the 90-degree hybrid circuit and including vanadium dioxide of a first composition that undergoes a phase transition between an insulating phase and a metallic phase in a first phase transition temperature range; a first stub connected to the first switch; a second switch connected to the first stub and including vanadium dioxide of a second composition that undergoes a phase transition between an insulating phase and a metallic phase in a second phase transition temperature range that is higher than the first phase transition temperature range; a second stub connected to the second switch and terminated at ground.

2. The variable length stub group includes: a first switch group constituted by two of the first switches; a first stub group constituted by two of the first stubs; a second switch group configured by two of the second switches; 2. The phase shifter according to claim 1, further comprising: a second stub group constituted by two of the second stubs.

3. The 90-degree hybrid circuit is It consists of four transmission lines of the same electrical length, 3. The phase shifter according to claim 2, wherein the electrical length of the first stub and the second stub is half the electrical length of the transmission line.

4. 4. The phase shifter according to claim 3, further comprising a control circuit that controls the temperatures of the two first switches included in the first switch group and the two second switches included in the second switch group.

5. The control circuit 5. The phase shifter according to claim 4, wherein at least one of the two first switches included in the first switch group and the two second switches included in the second switch group is temperature-controlled individually.

6. The control circuit 5. The phase shifter according to claim 4, wherein at least two of the two first switches included in the first switch group and the two second switches included in the second switch group are temperature-controlled collectively.

7. The first group of stubs includes: a plurality of the first stubs connected in series by at least one of the first switches; The second group of stubs includes:

3. The phase shifter according to claim 2, comprising a plurality of said second stubs connected in series by at least one of said second switches.

8. at least one dummy element containing vanadium dioxide that undergoes a phase transition in a known phase transition temperature range; The control circuit measuring a temperature according to a change in the electrical resistance value of the dummy element; 5. The phase shifter according to claim 4, wherein when an abnormality is detected in the measured temperature, two of the first switches included in the first switch group and two of the second switches included in the second switch group are controlled.

9. A phase shifter according to any one of claims 1 to 8; and a patch antenna disposed above the phase shifter.

10. 10. The antenna device according to claim 9, comprising a patch antenna array in which a plurality of said antenna units are arranged in an array.

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