Radio frequency switch and radio frequency device

Abstract

The invention discloses a radio frequency switch and a radio frequency device. The radio frequency switch comprises a reference signal line; the transmission line is positioned on one side of the reference signal line along the thickness direction; two ends of the transmission line are respectively used as an input end and an output end of the radio frequency switch; the heating piece is located between the reference signal line and the transmission line, and the heating piece, the transmission line and the reference signal line are insulated and spaced; the phase change structure is located between the reference signal line and the transmission line and connected with the reference signal line and the transmission line, and the phase change structure surrounds the heating piece; wherein the phase change structure is used for switching between a crystalline state and an amorphous state under the control of the heating temperature of the heating piece; the crystalline state is a state in which the reference signal line and the transmission line are conducted by the phase change structure, and the amorphous state is a state in which the reference signal line and the transmission line are disconnected by the phase change structure.

Description

Technical Field

[0001] The present disclosure relates to the field of radio frequency technology, and more particularly to a radio frequency switch and a radio frequency device. Background Art

[0002] As an indispensable part in fields such as radar, satellite communication, and mobile wireless communication, radio frequency switches are developing towards the directions of low insertion loss, high isolation, high cut-off frequency, wide bandwidth, low power consumption, and easy integration. Summary of the Invention

[0003] The present disclosure provides a radio frequency switch, comprising:

[0004] A reference signal line;

[0005] A transmission line located on one side of the reference signal line along its thickness direction; both ends of the transmission line are respectively used as the input end and the output end of the radio frequency switch;

[0006] A heating element located between the reference signal line and the transmission line, and insulated and spaced from both the transmission line and the reference signal line;

[0007] A phase change structure located between the reference signal line and the transmission line, and connected to the reference signal line and the transmission line, the phase change structure surrounding the heating element;

[0008] Wherein, the phase change structure is configured to switch between a crystalline state and an amorphous state under the control of the heating temperature of the heating element; the crystalline state is a state in which the phase change structure conducts the reference signal line and the transmission line, and the amorphous state is a state in which the phase change structure disconnects the reference signal line and the transmission line.

[0009] In some embodiments, a positive projection of the phase change structure on a reference plane is a continuous annular pattern, and the reference plane is a plane where the reference signal line is located.

[0010] In some embodiments, a positive projection of the phase change structure on the reference plane is a circular annular pattern; a positive projection of the heating element on the reference plane is located at the center of the continuous annular pattern.

[0011] In some embodiments, a ring width of the continuous annular pattern is 0.3 to 1 times a minimum distance from the heating element to the phase change structure.

[0012] In some embodiments, the radio frequency switch further comprises: an insulating layer disposed between the reference signal line and the transmission line;

[0013] The heating element is embedded in the insulating layer, and the phase change structure penetrates through the insulating layer.

[0014] In some embodiments, the insulating layer includes a first insulating portion and a second insulating portion. The first insulating portion is located between the heating element and the phase change structure, and the second insulating portion surrounds the phase change structure. The thermal conductivity of the first insulating portion is greater than that of the second insulating portion.

[0015] In some embodiments, the ratio of the height of the heating element to the height of the phase change structure is between 2 / 3 and 5 / 6.

[0016] In some embodiments, the orthographic projection of the phase change structure on the reference plane is within the orthographic projection range of the transmission line on the reference plane, and the reference plane is the plane where the reference signal line is located.

[0017] Embodiments of the present disclosure also provide a radio frequency switch, including:

[0018] A reference signal line;

[0019] An insulating layer located on one side of the reference signal line along its thickness direction;

[0020] A transmission line located on the side of the insulating layer away from the reference signal line; both ends of the transmission line are used as the input end and the output end of the radio frequency switch respectively;

[0021] A phase change structure penetrating through the insulating layer and connected between the reference signal line and the transmission line;

[0022] A heating element located between the reference signal line and the transmission line and surrounding the phase change structure; the heating element is embedded in the insulating layer and is insulated from both the reference signal line and the transmission line;

[0023] Wherein, the phase change structure is used to switch between a crystalline state and an amorphous state under the control of the heating temperature of the heating element; the crystalline state is the state in which the phase change structure conducts the reference signal line and the transmission line, and the amorphous state is the state in which the phase change structure disconnects the reference signal line and the transmission line;

[0024] The insulating layer includes a first insulating portion and a second insulating portion. The first insulating portion is located between the heating element and the phase change structure, and the second insulating portion surrounds the heating element. The thermal conductivity of the first insulating portion is greater than that of the second insulating portion.

[0025] In some embodiments, the thermal conductivity of the first insulating portion is 30 times or more that of the second insulating portion.

[0026] In some embodiments, the orthographic projection of the heating element on the reference plane is a continuous annular pattern, and the reference plane is the plane where the reference signal line is located.

[0027] In some embodiments, the positive projection of the heating element on the reference plane is an annular figure; the positive projection of the phase change structure on the reference plane is located at the center of the continuous annular figure.

[0028] In some embodiments, the phase change structure is cylindrical, and the diameter of the phase change structure is 0.3 to 1 times the minimum distance from the phase change structure to the heating element.

[0029] In some embodiments, the ratio of the height of the heating element to the height of the phase change structure is between 2 / 3 and 5 / 6.

[0030] An embodiment of the present disclosure further provides a communication device, including the above-mentioned radio frequency switch. Description of the Drawings

[0031] The drawings are used to provide a further understanding of the present disclosure, and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure, but do not constitute a limitation to the present disclosure. In the drawings:

[0032] Figure 1 It is a schematic diagram of the phase change switch provided in some embodiments.

[0033] Figure 2 It is a top view of the radio frequency switch provided in some embodiments of the present disclosure.

[0034] Figure 3 It is along the Figure 2 Cross-sectional view taken along line A-A' in.

[0035] Figure 4 It is along the Figure 2 Cross-sectional view taken along line A-A' in.

[0036] Figure 5 It is a schematic diagram of the radio frequency switch provided in still other embodiments of the present disclosure.

[0037] Figure 6 It is along Figure 5 Cross-sectional view taken along line B-B'. Detailed Description of the Embodiments

[0038] The following detailed description of the specific embodiments of the present disclosure will be given with reference to the drawings. It should be understood that the specific embodiments described herein are only for the purpose of illustrating and explaining the present disclosure, and are not used to limit the present disclosure.

[0039] To make the objectives, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are some but not all of the embodiments of the present disclosure. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present disclosure without creative efforts shall fall within the scope of protection of the present disclosure.

[0040] Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure shall have the ordinary meanings understood by those of ordinary skill in the art to which the present disclosure pertains. The terms "first", "second" and similar words used in the present disclosure do not denote any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "comprising" or "including" mean that the elements or items appearing before this word cover the elements or items listed after this word and their equivalents, without excluding other elements or items. The terms "connected" or "coupled" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0041] As used herein, "parallel" and "perpendicular" include the described situations and situations similar to the described situations, and the range of the similar situations is within an acceptable deviation range, where the acceptable deviation range is determined by those of ordinary skill in the art considering the measurements being discussed and the errors associated with the measurements of a particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, where the acceptable deviation range for approximate parallelism may be, for example, within 5° deviation; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, where the acceptable deviation range for approximate perpendicularity may also be, for example, within 5° deviation.

[0042] It should be understood that when a layer or element is referred to as being on another layer or substrate, it may be directly on the other layer or substrate, or there may be an intermediate layer between the layer or element and the other layer or substrate.

[0043] Exemplary embodiments are described herein with reference to cross-sectional views and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and regions is exaggerated for clarity. Accordingly, variations in the shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Thus, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but include shape deviations resulting from, for example, manufacturing. Thus, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shape of the regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0044] As an indispensable part in the fields such as radar, satellite communication, and mobile wireless communication, radio frequency switches are developing towards the direction of low insertion loss, high isolation, high cut-off frequency, wide bandwidth, low power consumption, and easy integration. The insertion loss of phase change material radio frequency switches (PCM RF switches, phase-change material RF switches, hereinafter referred to as phase change switches) in the microwave and millimeter wave frequency bands is the lowest among various switches currently, even lower than that of MEMS RF switches known for their low insertion loss.

[0045] Figure 1 The schematic diagram of the phase change switch provided in some embodiments is as Figure 1 shown. The phase change switch includes: a heating element 30, a first insulating layer 2a, a phase change layer 40, an input portion 51, and an output portion 52 disposed on a substrate 10. Among them, the first insulating layer 2a is located on the side of the heating element 30 away from the substrate 10, and the phase change layer 40 is located on the side of the first insulating layer 2a away from the substrate 10; the input portion 51 and the output portion 52 are located on the side of the first insulating layer 2a away from the substrate 10, and there is a gap between the two. For example, the input portion 51 and the output portion 52 are respectively connected to both ends of the phase change layer 40, and a second insulating layer 2b is disposed between the input portion 51 and the output portion 52.

[0046] The phase change layer 40 is made of a phase change material, and the phase change material has two states: a crystalline state and an amorphous state. By applying a DC pulse signal with a certain width and amplitude to the heating element 30, the switching of the state of the phase change material can be achieved. When the phase change material is in the crystalline state, by applying a large and narrow DC voltage (current) pulse to the heating element 30, the heating element 30 generates Joule heat that reaches the phase change layer 40 through the first insulating layer 2a, so that the temperature of the phase change layer 40 instantaneously reaches its melting temperature, and then the phase change material dissipates heat and completes rapid quenching, thereby forming an amorphous state; when the phase change material is in the amorphous state, a small and wide voltage (current) pulse is applied to the heating element 30, so that the temperature of the phase change layer 40 reaches above its crystallization temperature and below its melting temperature, and the phase change material completes the transition from the amorphous state to the crystalline state.

[0047] Among them, when the phase change material is in the crystalline state, its resistivity is very low, so that the input part 51 and the output part 52 can be conducted, which is equivalent to the phase change switch being in the on state. When the phase change material is in the amorphous state, its resistivity is very high, so that the input part 51 and the output part 52 are disconnected, which is equivalent to the phase change switch being in the off state. Among them, the change in the resistivity of the phase change material can reach four to five orders of magnitude.

[0048] However, for Figure 1 the phase change switch in [description], when the heating element 30 is heated, a part of the heat diffuses in the vertical direction and another part diffuses in the horizontal direction. The heat diffusing in the vertical direction reaches the phase change layer 40 from the heating element 30 through the first insulating layer 2a, inducing the phase change material to complete the phase change; but another part of the heat will diffuse along the horizontal direction through the insulating layer, resulting in a large amount of waste, and further reducing the heat utilization rate of the phase change switch.

[0049] Figure 2 is a top view of the radio frequency switch provided in some embodiments of the present disclosure. Figure 3 is along Figure 2 in the cross-sectional view taken along line A-A' in [description]. Figure 2 The radio frequency switch shown is a phase change switch. As Figure 2 shown, the radio frequency switch includes: a reference signal line 60, a transmission line 70, a heating element 30, and a phase change structure 41.

[0050] Among them, the reference signal line 60 can be a ground line. The transmission line 70 is located on one side of the reference signal line 60 along its thickness direction; both ends of the transmission line 70 are used as the input end and the output end of the radio frequency switch. Optionally, the transmission line 70 extends in the first direction; of course, the transmission line 70 can also be a bent line.

[0051] The heating element 30 is located between the reference signal line 60 and the transmission line 70, and is insulated and spaced from both the transmission line 70 and the reference signal line 60. Among them, the heating element 30 is a conductor, and by applying a voltage to the heating element 30, the heating element 30 generates Joule heat.

[0052] The phase change structure 41 is located between the reference signal line 60 and the transmission line 70, and is connected to the reference signal line 60 and the transmission line 70. The phase change structure 41 surrounds the heating element 30. Among them, the phase change structure 41 is made of a phase change material, and the phase change structure 41 is used to switch between the crystalline state and the amorphous state under the control of the heating temperature of the heating element 30; the crystalline state is the state in which the phase change structure 41 conducts the reference signal line 60 and the transmission line 70, and the amorphous state is the state in which the phase change structure 41 disconnects the reference signal line 60 and the transmission line 70. Optionally, the phase change material can be GeTe.

[0053] Among them, the on-off state of the RF switch can be controlled by controlling the heating temperature of the heating element 30. For example, by applying a large and narrow DC voltage (current) pulse to the heating element 30, the heating element 30 generates Joule heat to reach the phase change structure 41, so that the temperature of the phase change structure 41 instantaneously reaches its melting temperature. Then, the phase change structure 41 dissipates heat to complete rapid quenching, thereby forming an amorphous state. When the phase change material is in the amorphous state, its resistivity is very large, so that the transmission line 70 is disconnected from the reference signal line 60. At this time, both ends of the transmission line 70 are conducting, that is, the RF switch is in the on state. By applying a small and wide voltage (current) pulse to the heating element 30, the temperature of the phase change structure 41 is made to reach above its crystallization temperature and below its melting temperature, and the phase change material completes the transformation from the amorphous state to the crystalline state. When the phase change material is in the crystalline state, its resistivity is very low, so that the transmission line 70 is short-circuited with the reference signal line 60, that is, the RF switch is in the off state.

[0054] Compared with Figure 1 the phase change structure 41 shown, in Figure 2 the phase change structure 41 shown, since the phase change structure 41 surrounds the heating element 30, the heat generated by the heating element 30 can basically act on the phase change structure 41 as much as possible, thereby improving the heat utilization rate.

[0055] In some embodiments, the phase change structure 41 may further include a substrate 10. The reference signal line 60 is disposed on the substrate 10, and the transmission line 70 is located on a side of the reference signal line 60 away from the substrate 10. The substrate 10 may be a substrate made of an organic material such as a glass substrate or polyimide (PI). Among them, the reference signal line 60 may be directly disposed on the substrate 10, or other structures may be disposed between the reference signal line 60 and the substrate 10.

[0056] In some embodiments, the orthographic projection of the phase change structure 41 on the reference plane may be a continuous ring-shaped pattern or a discontinuous ring-shaped pattern. The so-called "discontinuous ring-shaped pattern" means that it includes a plurality of graph segments arranged at intervals, and the plurality of graph segments jointly surround the heating element 30. As a preferred embodiment of the present disclosure, the orthographic projection of the phase change structure 41 on the reference plane is a continuous ring-shaped pattern, so that the heat generated by the heating element 30 can basically act on the phase change structure 41 entirely.

[0057] Among them, the reference plane is the plane where the reference signal line 60 is located.

[0058] Among them, the continuous annular figure can be a square annular figure, a circular annular figure, or an elliptical annular figure. Preferably, the orthographic projection of the phase change structure 41 on the reference plane is a circular annular figure; the orthographic projection of the heating element 30 on the reference plane is located at the center of the continuous annular figure, so that the horizontal distances from each position on the phase change structure 41 to the heating element 30 are equal or substantially equal, improving the uniformity of heat reception at each position on the phase change structure 41.

[0059] Among them, when the distance between the phase change structure 41 and the heating element 30 is fixed, if the ring width d of the continuous annular figure (i.e., the wall thickness of the phase change structure 41) is too large, it is easy to cause the phase change structure 41 not to be fully heated and undergo a phase change; if the ring width d of the continuous annular figure is too small, it is easy to cause part of the heat to dissipate to the outside through the phase change structure 41, resulting in waste of heat. In some embodiments of the present disclosure, the ring width d of the continuous annular figure is 0.3 to 1 times the minimum distance d1 from the heating element 30 to the phase change structure 41, so as to ensure that each position of the phase change structure 41 is fully heated, enabling the phase change structure 41 to fully undergo a phase change; and reducing or avoiding waste of heat.

[0060] For example, the ring width d of the continuous annular figure is 0.3 to 0.5 times, or 0.5 to 0.7 times, or 0.7 to 0.8 times, or 0.8 to 1 times the minimum distance d1 from the heating element 30 to the phase change structure 41.

[0061] Among them, when the height of the phase change structure 41 is fixed, if the height h of the heating element 30 is too small, it is easy to cause less heat to be received at the higher positions of the phase change structure 41 and the phase change cannot be fully completed; if the height h of the heating element 30 is too high, it is easy to cause the heating element 30 to come into accidental contact with the transmission line 70; therefore, in some embodiments of the present disclosure, the ratio of the height h of the heating element 30 to the height h1 of the phase change structure 41 is between 2 / 3 and 5 / 6, so as to ensure that each position of the phase change structure 41 can be fully heated and prevent the heating element 30 from coming into accidental contact with the transmission line 70. The "height" of the heating element 30 (or the phase change structure 41) here refers to the vertical distance between the end of the heating element 30 (or the phase change structure 41) close to the reference signal line 60 and the end far from the reference signal line 60.

[0062] For example, the ratio of the height h of the heating element 30 to the height h1 of the phase change structure 41 is 2 / 3, or 0.7, or 0.75, or 0.8, or 5 / 6.

[0063] In some embodiments, as Figure 3 shown, the orthographic projection of the phase change structure 41 on the reference plane is within the orthographic projection range of the transmission line 70 on the reference plane, so as to ensure that when the phase change material is in the crystalline state, the phase change structure 41 can fully connect the transmission line 70 and the reference signal line 60, ensuring that the RF switch is in the off state. Among them, the reference plane is the plane where the reference signal line 60 is located.

[0064] In some embodiments, as Figure 2 shown, the RF switch further includes: an insulating layer 20 disposed between the reference signal line 60 and the transmission line 70; a heating element 30 embedded in the insulating layer 20, and the heating element 30 and the reference signal line 60 are spaced apart by the insulating layer 20 to prevent short - circuiting between the two. The phase - change structure 41 penetrates through the insulating layer 20. By providing the insulating layer 20, it can support the transmission line 70, the heating element 30, and the phase - change structure 41, improving the structural stability of the RF switch. Also, the insulating layer 20 can reduce the heat dissipation of the heating element 30 to the outside.

[0065] Among them, the part of the insulating layer 20 within the region surrounded by the phase - change structure 41 and the part around the phase - change structure 41 may have the same or different materials. For example, the insulating layer 20 at different positions is made of silicon oxide or silicon nitride.

[0066] Figure 4 For another embodiment provided in the present disclosure, it is a cross - sectional view along the Figure 2 A - A' line in. In some embodiments, the insulating layer 20 includes a first insulating portion 21 and a second insulating portion 22. The first insulating portion 21 is located between the heating element 30 and the phase - change structure 41, and the second insulating portion 22 surrounds the phase - change structure 41. The thermal conductivity of the first insulating portion 21 is greater than that of the second insulating portion 22, which is beneficial to quickly conduct the heat of the heating element 30 to the phase - change structure 41, while reducing the continuous outward diffusion of the heat on the phase - change structure 41 and further improving the heat utilization rate.

[0067] In some embodiments, the thermal conductivity of the first insulating portion 21 can be 30 times or more, or 50 times or more, or 100 times or more that of the second insulating portion 22.

[0068] In some embodiments, the thermal conductivity of the first insulating portion 21 can be 150 times or more that of the second insulating portion 22, so as to quickly conduct the heat of the heating element 30 to the phase - change structure 41, while reducing the continuous outward diffusion of the heat on the phase - change structure 41. For example, the material of the first insulating portion 21 may include AlN, and the material of the second insulating portion 22 may be SiO2.

[0069] In some embodiments, the radio frequency switch may further include a power supply line (not shown), which is electrically connected to the heating element 30 and is insulated and spaced apart from both the reference signal line 60 and the transmission line 70. The power supply line is used to provide an electrical signal to the heating element 30, so that the heating element 30 generates heat. Wherein, when the orthographic projection of the phase change structure 41 on the reference plane is a continuous circular pattern, an avoidance hole may be provided on the phase change structure 41, and the power supply line passes through the avoidance hole and is electrically connected to the heating element 30. Alternatively, the power supply line may also bypass the top end of the phase change structure 41 and be electrically connected to the heating element 30.

[0070] Wherein, the material of the heating element 30 may be tungsten (W). The materials of the transmission line 70 and the reference signal line 60 may be metal materials with relatively high conductivity, such as copper.

[0071] Figure 5 Schematic diagram of the radio frequency switch provided in some further embodiments of the present disclosure Figure 6 For Figure 5 Cross-sectional view along the B-B' line in Figure 5 and Figure 6 As shown, in some embodiments, the radio frequency switch includes: a reference signal line 60, a transmission line 70, an insulating layer 20, a phase change structure 41, and a heating element 30.

[0072] Optionally, the radio frequency switch further includes a substrate 10. The reference signal line 60 is disposed on the substrate 10, and the transmission line 70 is located on one side of the reference signal line 60 along its thickness direction; both ends of the transmission line 70 are used as the input end and the output end of the radio frequency switch respectively. Optionally, the transmission line 70 extends along the first direction; or, the transmission line 70 is a bent line.

[0073] The phase change structure 41 is connected between the reference signal line 60 and the transmission line 70. The heating element 30 is located between the reference signal line 60 and the transmission line 70 and surrounds the phase change structure 41; the heating element 30 is insulated and spaced apart from both the reference signal line 60 and the transmission line 70. Wherein, the heating element 30 is a conductor, and by applying a voltage to the heating element 30, the heating element 30 generates Joule heat.

[0074] Wherein, the phase change structure 41 is made of a phase change material. The phase change structure 41 is used to switch between a crystalline state and an amorphous state under the control of the heating temperature of the heating element 30; the crystalline state is the state in which the phase change structure 41 conducts the reference signal line 60 and the transmission line 70, and the amorphous state is the state in which the phase change structure 41 disconnects the reference signal line 60 and the transmission line 70. Optionally, the phase change material may be GeTe.

[0075] Among them, the phase change structure 41 is heated by the heating element 30, so as to control the switching of the phase change structure 41 between the crystalline state and the amorphous state, and further, the RF switch can be controlled to have an off state and an on state. By applying a large and narrow DC voltage (current) pulse to the heating element 30, the heating element 30 generates Joule heat to reach the phase change structure 41, so that the temperature of the phase change structure 41 instantaneously reaches its melting temperature, and then the phase change structure 41 dissipates heat to complete rapid quenching, thereby forming an amorphous state; when the phase change material is in the amorphous state, its resistivity is very high, so that the transmission line 70 is disconnected from the reference signal line 60. At this time, both ends of the transmission line 70 are conducting, that is, the RF switch is in the on state. By applying a small and wide voltage (current) pulse to the heating element 30, the temperature of the phase change structure 41 is made to reach above its crystallization temperature and below its melting temperature, and the phase change material completes the transformation from the amorphous state to the crystalline state. When the phase change material is in the crystalline state, its resistivity is very low, so that the transmission line 70 is short-circuited with the reference signal line 60, that is, the RF switch is in the off state.

[0076] As Figure 6 shown, the insulating layer 20 is located on one side of the reference signal line 60 along its thickness direction, and the transmission line 70 is located on the side of the insulating layer 20 away from the reference signal line 60; the phase change structure 41 penetrates through the insulating layer 20; the heating element 30 is embedded in the insulating layer 20, and the heating element 30 is spaced apart from the reference signal line 60 and the transmission line 70 by the insulating layer 20. The insulating layer 20 includes a first insulating portion 21 and a second insulating portion 22. The first insulating portion 21 is located between the heating element 30 and the phase change structure 41, and the second insulating portion 22 surrounds the heating element 30. The thermal conductivity of the first insulating portion 21 is greater than that of the second insulating portion 22.

[0077] In Figure 6 it, since the second insulating portion 22 is disposed around the heating element 30, the first insulating portion 21 is located between the heating element 30 and the phase change structure 41, and the thermal conductivity of the first insulating portion 21 is greater than that of the second insulating portion 22, the heat of the heating element 30 can be quickly conducted to the phase change structure 41 by means of the first insulating portion 21 with a higher thermal conductivity, and at the same time, the heat on the phase change structure 41 from continuing to diffuse outward is reduced, further improving the heat utilization rate.

[0078] In some embodiments, the thermal conductivity of the first insulating portion 21 can be 30 times or more, or 50 times or more, or 100 times or more that of the second insulating portion 22.

[0079] In some embodiments, the thermal conductivity of the first insulating portion 21 can be 150 times or more that of the second insulating portion 22, so as to quickly conduct the heat of the heating element 30 to the phase change structure 41, and at the same time, reduce the heat on the phase change structure 41 from continuing to diffuse outward. For example, the material of the first insulating portion 21 can include AlN, and the material of the second insulating portion 22 can be SiO2.

[0080] In some embodiments, as Figure 5 shown, the orthographic projection of the heating element 30 on the reference plane may be a continuous annular pattern or a discontinuous annular pattern. The so-called "discontinuous annular pattern" means that the heating element 30 includes a plurality of spaced-apart graphic segments, and the plurality of graphic segments jointly surround the phase change structure 41. As a preferred embodiment of the present disclosure, the orthographic projection of the heating element 30 on the reference plane is a continuous annular pattern, so that the heat generated by the heating element 30 can basically act fully on the phase change structure 41, and each position in the circumferential direction of the phase change structure 41 is evenly heated. The reference plane is the plane where the reference signal line 60 is located.

[0081] Among them, the continuous annular pattern presented by the heating element 30 may be a square annular pattern, a circular annular pattern, or an elliptical annular pattern. Preferably, the orthographic projection of the heating element 30 on the reference plane is a circular annular pattern; the orthographic projection of the phase change structure 41 on the reference plane is located at the center of the continuous annular pattern presented by the heating element 30, so that the horizontal distance from each position on the phase change structure 41 to the heating element 30 is equal or substantially equal, improving the uniformity of heating at each position on the phase change structure 41.

[0082] In one example, the phase change structure 41 is cylindrical, and the diameter d0 of the phase change structure 41 is 0.3 to 1 times the minimum distance d1 from the phase change structure 41 to the heating element 30, so as to ensure that each position of the phase change structure 41 is fully heated, enabling the phase change structure 41 to fully undergo a phase change; and reducing or avoiding waste of heat.

[0083] For example, the diameter d0 of the phase change structure 41 is 0.3 to 0.5 times, or 0.5 to 0.7 times, or 0.7 to 0.8 times, or 0.8 to 1 times the minimum distance d1 from the heating element 30 to the phase change structure 41.

[0084] In some embodiments, the ratio of the height h of the heating element 30 to the height h1 of the phase change structure 41 is between 2 / 3 and 5 / 6, so as to ensure that each position of the phase change structure 41 can be fully heated and prevent the heating element 30 from making accidental contact with the transmission line 70.

[0085] For example, the ratio of the height h of the heating element 30 to the height h1 of the phase change structure 41 is 2 / 3, or 0.7, or 0.75, or 0.8, or 5 / 6.

[0086] In Figure 6 it, the radio frequency switch may similarly include a power supply line (not shown), which is electrically connected to the heating element 30 and is insulated and spaced from both the reference signal line 60 and the transmission line 70. The power supply line is used to provide an electrical signal to the heating element 30, so that the heating element 30 generates heat.

[0087] It should be noted that the above embodiments are described by taking the case where the transmission line 70 is located on the side of the reference signal line 60 away from the substrate 10 as an example. In other embodiments, the transmission line 70 may also be disposed on the substrate 10, and the reference signal line 60 may be disposed on the side of the transmission line 70 close to the substrate 10.

[0088] An embodiment of the present disclosure further provides a communication device, including the radio frequency switch in the above embodiment. For example, the communication device may be an antenna.

[0089] It can be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principle of the present disclosure. However, the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present disclosure, and these modifications and improvements are also regarded as the protection scope of the present disclosure.

Claims

1. A radio frequency switch, characterized in that, Comprising: A reference signal line; A transmission line located on one side of the reference signal line along its thickness direction; both ends of the transmission line are respectively used as the input end and the output end of the radio frequency switch; A heating element located between the reference signal line and the transmission line and insulated from both the transmission line and the reference signal line; A phase change structure located between the reference signal line and the transmission line and connected to both the reference signal line and the transmission line, and the phase change structure surrounds the heating element; Wherein, the phase change structure is used to switch between a crystalline state and an amorphous state under the control of the heating temperature of the heating element; the crystalline state is the state in which the phase change structure conducts the reference signal line and the transmission line, and the amorphous state is the state in which the phase change structure disconnects the reference signal line and the transmission line.

2. The RF switch according to claim 1, wherein The positive projection of the phase change structure on the reference plane is a continuous circular ring pattern, and the reference plane is the plane where the reference signal line is located.

3. The RF switch according to claim 2, characterized in that The positive projection of the phase change structure on the reference plane is a circular ring pattern; the positive projection of the heating element on the reference plane is located at the center of the continuous circular ring pattern.

4. The RF switch according to claim 2, wherein The ring width of the continuous circular ring pattern is 0.3 to 1 times the minimum distance from the heating element to the phase change structure.

5. The RF switch according to any one of claims 1 to 4, characterized in that, The radio frequency switch further comprises: an insulating layer disposed between the reference signal line and the transmission line; The heating element is embedded in the insulating layer, and the phase change structure penetrates through the insulating layer.

6. The RF switch according to claim 5, wherein The insulating layer includes a first insulating portion and a second insulating portion. The first insulating portion is located between the heating element and the phase change structure, and the second insulating portion surrounds the phase change structure. The thermal conductivity of the first insulating portion is greater than that of the second insulating portion.

7. The RF switch according to any one of claims 1 to 4, characterized in that, The ratio of the height of the heating element to the height of the phase change structure is between 2 / 3 and 5 / 6.

8. The RF switch according to any one of claims 1 to 4, characterized in that, The positive projection of the phase change structure on the reference plane is located within the positive projection of the transmission line on the reference plane, and the reference plane is the plane where the reference signal line is located.

9. A radio frequency switch, characterized in that, Comprising: A reference signal line; An insulating layer located on one side of the reference signal line along its thickness direction; A transmission line located on the side of the insulating layer away from the reference signal line; both ends of the transmission line are respectively used as the input end and the output end of the radio frequency switch; A phase change structure that penetrates through the insulating layer and is connected between the reference signal line and the transmission line; A heating element located between the reference signal line and the transmission line and surrounding the phase change structure; the heating element is embedded in the insulating layer and is insulated from both the reference signal line and the transmission line; Wherein, the phase change structure is used to switch between a crystalline state and an amorphous state under the control of the heating temperature of the heating element; the crystalline state is the state in which the phase change structure conducts the reference signal line and the transmission line, and the amorphous state is the state in which the phase change structure disconnects the reference signal line and the transmission line; The insulating layer includes a first insulating portion and a second insulating portion. The first insulating portion is located between the heating element and the phase change structure, and the second insulating portion surrounds the heating element. The thermal conductivity of the first insulating portion is greater than that of the second insulating portion.

10. The RF switch according to claim 9, wherein The thermal conductivity of the first insulating portion is 30 times or more that of the second insulating portion.

11. The RF switch according to claim 9, characterized in that, The orthographic projection of the heating element on the reference plane is a continuous annular pattern, and the reference plane is the plane where the reference signal line is located.

12. The RF switch according to any one of claims 9 to 11, characterized in that, The orthographic projection of the heating element on the reference plane is an annular pattern; the orthographic projection of the phase change structure on the reference plane is located at the center of the continuous annular pattern.

13. The RF switch according to any one of claims 9 to 11, characterized in that, The phase change structure is cylindrical, and the diameter of the phase change structure is 0.3 to 1 times the minimum distance from the phase change structure to the heating element.

14. The RF switch according to any one of claims 9 to 11, characterized in that The ratio of the height of the heating element to the height of the phase change structure is between 2 / 3 and 5 / 6.

15. A communication device, characterized in that, Including the radio frequency switch according to any one of claims 1 to 14.

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