A microwave combiner

Abstract

This application provides a microwave combiner and microwave device, including a housing formed by a fully enclosed metal cavity; at least two combining units, each connected by a stripline, with the at least two combining units converging at a combining node; and a heat dissipation structure disposed within the housing, comprising a heat dissipation shell and a heat-conducting component. The heat dissipation shell is attached to the side of the housing, and the heat-conducting component includes a first end, a middle end, and a second end connected sequentially along its length. The first end is connected to the stripline of the combining node, and the second end extends out of the heat dissipation shell and is attached to the housing. The heat dissipation shell has an inner cavity filled with a conductive medium, and the middle end is suspended in the conductive medium. When microwave synthesis causes the heat generated at the combining node to exceed a threshold, the middle end shifts, causing its side to attach to the heat dissipation shell, thereby dissipating heat through the heat dissipation shell and the housing. The microwave combiner and microwave device provided above solve the overheating problem by adding a heat dissipation structure.

Description

Technical Field

[0001] This application relates to the fields of microwave and radio frequency communication, and in particular to a microwave combiner. Background Technology

[0002] With the rapid development of modern communication, military, and energy technologies, the demand for high-power microwaves is increasing. Microwave power combiners, as key components, combine the power of multiple microwave sources to achieve higher output power and meet the application requirements of various fields. Phase and amplitude control are crucial during power combining. The combining efficiency is highest when two signals are of equal amplitude and in phase. If there is a phase difference or amplitude ratio between the two signals, the combining efficiency will decrease. Therefore, precise control methods are needed to ensure good consistency and synchronization of the signals from each microwave source during combining.

[0003] In microwave communication systems, combiners can merge two or more microwave signals into a single signal. The function of a combiner is to connect microwave signals through a common point. Within a combiner, the microwave signal is transmitted via a microwave transmission line. A microwave transmission line is a structure used to transmit electromagnetic signals in the microwave frequency band (generally 300MHz to 300GHz), and its construction directly affects key performance aspects such as signal loss, bandwidth, transmission speed, and impedance matching.

[0004] When microwave combiners operate at high power and multiple frequency bands, the combining nodes are prone to significant heat generation due to signal superposition. If heat cannot be dissipated in time, it will cause losses in the microwave signal during transmission, affecting the transmission performance of the signal transmission line and leading to a decrease in combining efficiency. However, current technologies can only improve the heat dissipation performance of the combiner housing, not the heat dissipation performance of the combining point in the transmission line. If the heat at the combining point cannot be dissipated in time, it will cause certain losses in the transmission lines at both ends of the combining point, causing thermal deformation and resulting in signal drift. Taking a 0.25 nm operating wavelength transmission line as an example, a single 0.25 nm operating wavelength transmission line only causes about 0.26° phase drift, but in a multi-segment transmission line or filter cascade structure, the cumulative drift may reach several degrees or even exceed the limit. To ensure the transmission performance of the combiner transmission line, we also need to consider the dielectric constant shift and characteristic impedance variation caused by temperature changes. Therefore, we need to solve the problems of local overheating at the combining node, non-uniform thermal deformation of the transmission line due to excessive local heat, signal distortion due to low heat dissipation efficiency, and shortened device lifespan in traditional heat dissipation solutions. Summary of the Invention

[0005] In view of this, it is necessary to provide a microwave combiner to solve the above problems.

[0006] Embodiments of this application provide a microwave combiner, including...

[0007] The outer casing is formed by a fully enclosed metal cavity;

[0008] At least two merging units, each of which is connected by a stripline, and at least two merging units converge at a merging node;

[0009] A heat dissipation structure is disposed inside the outer casing. The heat dissipation structure includes a heat dissipation shell and a heat-conducting component. The side of the heat dissipation shell is attached to the outer casing. The heat-conducting component includes a first end, a middle end and a second end connected in sequence along its length direction. The first end is connected to the strip line of the merging node, and the second end extends out of the heat dissipation shell and is attached to the outer casing.

[0010] The heat dissipation shell has an inner cavity filled with a conductive medium. The middle end is suspended in the conductive medium. When the heat generated at the combining node exceeds a threshold during microwave synthesis, the middle end is offset so that its side is attached to the heat dissipation shell, so that heat can be dissipated through the heat dissipation shell and the outer shell.

[0011] In at least one embodiment of this application, the heat dissipation shell includes a first dielectric layer and a second dielectric layer disposed opposite to and attached to the outer shell. When the merging node generates heat and is conducted to the inner cavity through the heat-conducting element, the dielectric constant of the first dielectric layer and the second dielectric layer is changed, causing the heat-conducting element to shift. The heat of the merging node is conducted to the heat dissipation shell for heat dissipation through the first dielectric layer and the second dielectric layer.

[0012] In at least one embodiment of this application, the heat dissipation shell has an electric field concentration groove, the electric field concentration groove is formed on the first dielectric layer, the electric field concentration groove is a blind hole, the direction of the merging node pointing to the heat dissipation structure is defined as the first direction, and the electric field concentration groove extends from the merging node along the first direction.

[0013] Wherein, along the first direction, the length of the electric field concentration tank is defined as B, and the wavelength of the synthesized microwave is defined as λ, where B = λ / 4.

[0014] In at least one embodiment of this application, the heat-conducting element has a first side facing the first dielectric layer and a second side facing the second dielectric layer.

[0015] The first side is coated with a first copper foil electrode layer, and the second side is coated with a second copper foil electrode layer. A first capacitor is formed between the first copper foil electrode layer and the first dielectric layer to concentrate an electric field. A second capacitor is formed between the second copper foil electrode layer and the second dielectric layer to generate an electric field force together with the first capacitor to drive the middle end of the heat-conducting component to move.

[0016] In at least one embodiment of this application, the first dielectric layer and the second dielectric layer are made of the same dielectric constant material, the thickness of the first dielectric layer is defined as J, and the thickness of the second dielectric layer is defined as K, wherein J≠K.

[0017] In at least one embodiment of this application, the first dielectric layer and the second dielectric layer are made of the same ceramic material, wherein J / K≤1 / 4. When the junction node heats up and is conducted to the inner cavity through the intermediate end, the heat-conducting element heats up, changing the dielectric constant of the first dielectric layer and the second dielectric layer to drive the heat-conducting element to shift.

[0018] The internal cavity generates a local temperature gradient, which causes the heat-conducting component to shift. The heat from the merging node is conducted to the heat dissipation shell through the first dielectric layer and the second dielectric layer.

[0019] In at least one embodiment of this application, the first dielectric layer is a ceramic plate, the second dielectric layer is a foam board, the thickness of the first dielectric layer is defined as J, and the thickness of the second dielectric layer is defined as K, where J = K. When the junction node heats up and is conducted to the inner cavity through the heat conductor, the heat conductor heats up, changing the dielectric constant of the first dielectric layer and the second dielectric layer to drive the heat conductor to shift.

[0020] In at least one embodiment of this application, the microwave combiner further includes a heat transfer element, one end of which is disposed on the heat conduction element and the other end of which is disposed on the outer casing, for transferring heat from the heat conduction element to the outer casing.

[0021] In at least one embodiment of this application, the heat transfer element is a base structure.

[0022] A microwave device comprising any of the microwave combiners described above.

[0023] The microwave combiner and microwave equipment described above solve the problems of localized overheating at the combining node, non-uniform thermal deformation of the transmission line due to excessive localized heat, signal distortion caused by low heat dissipation efficiency, and short device lifespan by adding a heat dissipation structure to the combining node. This invention improves the heat dissipation performance of the combiner and power combining device, thus enabling its application in high-power combining scenarios. Attached Figure Description

[0024] Figure 1 A three-dimensional structural schematic diagram of a microwave combiner provided in this application embodiment;

[0025] Figure 2 A cross-sectional view of a microwave combiner provided in an embodiment of this application;

[0026] Figure 3 for Figure 2 A magnified view at point M;

[0027] Figure 4 for Figure 1 The cross-sectional view of the heat dissipation structure of the microwave combiner before offset;

[0028] Figure 5 for Figure 4 A magnified view at point N;

[0029] Figure 6 for Figure 1 The cross-sectional view of the heat dissipation structure of the microwave combiner after offset;

[0030] Figure 7 This is a schematic diagram of the internal heat transfer element of a microwave combiner provided in an embodiment of this application.

[0031] Explanation of main component symbols

[0032] 100. Microwave combiner; 10. Housing; 20. Combining unit; 201. Combining node; 30. Heat dissipation structure; 31. Heat dissipation shell; 31a. Inner cavity; 31b. Electric field concentration slot; 301. Heat-conducting component; 3011. First end; 3012. Middle end; 3013. Second end; 301a. First surface; 301b. Second surface; 301c. First copper foil electrode layer; 301d. Second copper foil electrode layer; 302. Conducting medium; 303. First dielectric layer; 304. Second dielectric layer; 305. Heat transfer component; 306. Elastic gasket; 307. Fin; X: First direction; B: Length of electric field concentration slot. Detailed Implementation

[0033] The embodiments of this application will now be described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0034] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or may also have an intervening component. When a component is considered to be "placed" on another component, it can be directly placed on the other component or may also have an intervening component. The terms "top," "bottom," "upper," "lower," "left," "right," "front," "back," and similar expressions used in this article are for illustrative purposes only.

[0035] This application provides a microwave combiner that can be used for high-power microwave combining. It solves the problems of significant temperature rise at the combining node in existing microwave combiners, which leads to drift of the dielectric constant of the transmission microwave line and aging of the device due to overheating.

[0036] Example 1

[0037] Please see Figures 1-7 An embodiment of this application provides a microwave combiner, including a housing;

[0038] Specifically, the outer casing 10 is enclosed by a fully sealed metal cavity. Structurally, the outer casing constitutes the shielding cavity of the microwave combiner 100, serving as external protection for the entire microwave combiner 100. It is used to fix the internal components, ensuring that the microwave combiner 100 is in a closed electromagnetic environment during operation, preventing external electromagnetic interference, maintaining the stability of the internal field distribution, and making the microwave combiner 100 suitable for microwave or millimeter-wave frequency bands. The fully sealed metal cavity of the outer casing 10 effectively reduces leakage radiation, improves signal isolation, and enhances electromagnetic compatibility. The metal casing provides a good grounding environment for the microwave combiner 100 and lays the foundation for heat dissipation conduction paths.

[0039] At least two merging units 20, and at least two merging units 20 converge at a merging node 201.

[0040] Specifically, each combining unit 20 includes at least two input terminals and one output terminal. In this embodiment, at least two combining units 20 are included, that is, at least two output terminals are connected at the combining node 201 and microwave power combining is performed. When microwave power combining occurs, the microwave signal forms a signal superposition area at the combining node 201. Since the signal superposition will have power superposition and standing wave reflection phenomena, a large amount of heat will be generated locally at the combining node 201. Since the combiner 100 is a closed metal cavity, the heat generated locally at the combining node 201 depends on passive conduction. A heat dissipation structure 30 is connected at the combining node 201. One end of the heat dissipation structure 30 is provided on the combining node 201, and the other end extends and fits against the shell, which is used to conduct a large amount of heat from the combining node 201 to the metal shell 10.

[0041] Furthermore, each combining unit 20 is formed by connecting striplines (made of high-purity electrolytic copper) in a circular connection to form at least two input terminals and one output terminal. The entire combining unit 20 provides a path for microwave conduction. The heat dissipation structure 30 includes a heat dissipation shell 31 and a heat-conducting element 301. The heat dissipation shell 31 is attached to the outer shell 10, and one end of the heat-conducting element 301 is connected to the stripline of the combining node 201, while the other end is attached to the outer shell 10. Preferably, to ensure ease of manufacturing of the microwave combiner, in one specific embodiment, the heat-conducting element 301 is also made of high-purity electrolytic copper and is integrally formed with the striplines of each combining unit 20 on the combining node 201. That is, the heat-conducting element 301 in the heat dissipation structure 30 is made of the same material as the striplines and is a branch structure connected together. It only plays a heat dissipation role and does not undertake microwave conduction.

[0042] Furthermore, the heat dissipation shell 31 is a shell structure that wraps around the heat-conducting component 301. Specifically, its outer surface (i.e., as shown in the image) Figure 3 The vertical upper and lower surfaces shown are attached to the outer shell 10 to dissipate the heat transferred from the heat-conducting component 301 through the heat dissipation shell 31-outer shell 10 when the heat is transferred.

[0043] Furthermore, the cross-sectional area of ​​the heat sink 31 can be equal to or greater than the cross-sectional area of ​​the stripline on the combining unit 20. In one specific embodiment, the cross-sectional area of ​​the heat sink 31 is equal to the cross-sectional area of ​​the stripline (i.e., the heat dissipation structure 30 appears to be the same size as a single stripline), in which case the cross-sectional area of ​​the heat-conducting element 301 is smaller than the cross-sectional area of ​​a single stripline. In another embodiment, the cross-sectional area of ​​the heat-conducting element 301 is equal to the cross-sectional area of ​​a single stripline (i.e., the heat-conducting element 301 is completely identical to a single stripline), in which case the size of the heat sink 31 is larger than a single stripline, and its appearance shows that the heat sink 31 is wrapped around the stripline.

[0044] To facilitate heat dissipation, the heat sink 31 has an inner cavity 31a filled with a conductive medium 302. This medium allows the heat-conducting element 301 to shift and adhere to the heat sink 31 during microwave synthesis and when the combining node 201 generates heat, thus dissipating heat through the heat sink 31 and the outer shell 10. In one specific embodiment, the conductive medium 302 is air.

[0045] Furthermore, the heat dissipation shell 31 includes a first dielectric layer 303 and a second dielectric layer 304 that are disposed opposite to and attached to the outer shell 10. When the junction node 201 generates heat and is conducted to the inner cavity 31a through the heat conductor 301, the dielectric constant of the first dielectric layer 303 and the second dielectric layer 304 is changed, causing the heat conductor 301 to shift. The heat from the junction node is then conducted to the heat dissipation shell 31 through the first dielectric layer and the second dielectric layer for heat dissipation.

[0046] In one specific embodiment, the outer shell 10 is a metal shell wrapped around the outermost layer, and the heat dissipation structure 30 is a structural component disposed inside the outer shell 10, used to contact the heat source generated inside and transfer the heat source to the outer shell 10.

[0047] In one specific embodiment, the heat-conducting element 301 includes a first end 3011, a middle end 3012, and a second end 3013 connected sequentially along its length. It is understood that the heat-conducting element 301 here is a long, straight copper sheet, and the first end 3011, the middle end 3012, and the second end 3013 are an integral structure. The first end 3013 is connected to the merging node 201, the second end 3013 extends out of the heat sink 31 and is connected to the inner wall of the outer casing 10, and the middle end 3012 is suspended within the heat sink 31 with both ends fixedly connected. When the combining node 201 is heated, the heat is transferred from the first end 3011 to the middle end 3012. The dielectric constants of the first dielectric layer 303 and the second dielectric layer 304 at both ends of the middle end 3012 change with the temperature, thereby causing a change in the electric field around the middle layer 3012. This drives the middle end 3012 to shift towards the first dielectric layer 303 or the second dielectric layer 304 (the change in electric field caused by the change in dielectric constant is common knowledge in the field of microwave conduction and will not be discussed further here).

[0048] Furthermore, since the intermediate end 3012 is a copper sheet, and copper is an elastic metal material, when the temperature of the merging node 201 returns to normal, the temperature around the intermediate end 3012 recovers. The dielectric constant of the first dielectric layer 303 and the second dielectric layer 304 recovers due to the temperature recovery, thereby removing the electric field force acting on the intermediate end 3012. The intermediate end 3012 returns to its original state due to the high elasticity of its copper.

[0049] In the embodiments of this application, the middle end 3012 is suspended. Specifically, the first end 3011 is fixedly connected to the merging node 201, and the second end 3013 is fixedly connected to the outer shell 10. When the first end 3011 and the second end 3013 are fixed, the middle end 3012 is pulled up by the two ends and suspended.

[0050] It should be noted that the first end 3011 of this application is connected to the microwave conduction combining node 201. Only when the temperature is too high and exceeds the threshold is it necessary to contact the middle end 3012 with the outer casing 10 for heat dissipation. During normal operation of the microwave combiner, in order to avoid the middle end 3012 contacting the outer casing 10 and affecting the microwave combining efficiency, it is usually necessary to suspend the middle end 3012 to avoid contact with the outer casing 10. Therefore, this application, by making the heat-conducting element 301 into the first end 3011, the middle end 3012, and the second end 3013 in sequence, and suspending the middle end 3012, greatly improves the combining quality of the microwave combiner compared to the traditional method of directly grounding or contacting the outer casing 10 with the heat-conducting element 301.

[0051] Furthermore, the aforementioned threshold is a critical temperature point that affects microwave synthesis during the synthesis process. When the temperature exceeds this critical point, the microwave synthesis will change due to temperature variations. It should be noted that this threshold is affected by factors such as microwave power, wavelength, and frequency. Moreover, in this field, there are devices capable of measuring the temperature threshold present during the synthesis process based on the microwave's power, wavelength, and frequency. This measurement process is common knowledge to those skilled in the art and will not be elaborated upon further here.

[0052] In one specific embodiment, the first dielectric layer and the second dielectric layer are made of the same dielectric material. The thickness of the first dielectric layer is defined as J, and the thickness of the second dielectric layer is defined as K, where J ≠ K. Specifically, the heat-conducting element 301 is a central copper flat wire sandwiched between the first dielectric layer 303 and the second dielectric layer 304. The dielectric layer is used to support the conductor and control the propagation speed and impedance of electromagnetic waves. The dielectric layer is generally an electrically insulating material, commonly referred to as a dielectric substrate. Different dielectric substrates have different dielectric constants and coefficients of thermal expansion. Therefore, the material and thickness of the dielectric layer have a significant impact on the performance of the transmission line. In this embodiment, the heat-conducting element 301 used in the heat dissipation structure 30 is a strip wire structure. When the combining node 201 heats up, the heat is conducted through the heat conductor 301 to the microstrip line cavity 31a. The conductive medium 302 is heated, and the high temperature causes the materials of the first dielectric layer 303 and the second dielectric layer 304 to expand. Due to the difference in the thermal expansion coefficients of the dielectric materials, the thickness of the dielectric layer changes, indirectly causing changes in the electrical center, impedance, coupling characteristics, etc. of the heat conductor 301. As a result, the relative position of the signal conductor will shift relative to the upper and lower ground layers. Different dielectric constants have different sensitivities to temperature. When the temperature rises, due to the change in dielectric constant, the dielectric constant of one side of the dielectric layer increases more, resulting in a redistribution of the electric field. The electrical center of the heat conductor 301 is more biased towards the side with the more significant change in dielectric constant, so that more heat passes through the conductive medium 302, thereby increasing heat dissipation and reducing the impact of high temperature on the loss of the combining unit 20.

[0053] Specifically, in this embodiment, the first dielectric layer 303 and the second dielectric layer 304 are made of the same dielectric constant material. The thickness of the first dielectric layer is defined as J, and the thickness of the second dielectric layer is defined as K, where J ≠ K. In this embodiment, the use of the same dielectric constant material for the first dielectric layer 303 and the second dielectric layer 304 ensures that the basic dielectric properties of the two dielectric layers are the same, which can reduce electromagnetic performance fluctuations caused by material differences, reduce signal transmission loss of the combining unit 20, and improve the electromagnetic stability of the combiner 100. The thickness J of the first dielectric layer 303 is not equal to the thickness K of the second dielectric layer 304. The purpose is to form an asymmetric heat dissipation path in the heat dissipation structure 30 through the thickness difference, and to regulate the gradient of dielectric constant change by utilizing the difference in heat conduction rate, thereby accelerating the heat transfer from the combining node 201 to the outer shell 1. The heat is conducted in a directional manner. Specifically, in this embodiment, J is defined as a thicker layer and K as a thinner layer. When the merging node 201 heats up, the heat is conducted through the heat conductor 301 to the inner cavity of the heat dissipation structure 30. The conductive medium 302 is heated and the heat diffuses through the heat conductor 301 to the first dielectric layer 303 and the second dielectric layer 304. Since J≠K, the heat is conducted faster in the thinner layer, resulting in a local temperature difference between the two dielectric layers (temperature gradient ΔT). At the same time, the increase in temperature will change the dielectric constant of the dielectric material. The higher the temperature, the greater the change in dielectric constant (common in ceramic materials). The thicker layer has a higher thermal resistance and a higher temperature, so its dielectric constant decreases more than that of the thinner layer, forming a dielectric constant gradient. The dielectric constant gradient causes the electric field distribution around the heat conductor 301 to be uneven, generating an electromagnetic force that pushes the heat conductor 301 to shift towards the side with a lower dielectric constant (i.e., the direction of the thicker layer with a higher temperature and a lower dielectric constant). When combining multi-band signals, high-frequency heat generation is severe, requiring rapid heat dissipation to ensure signal quality. The thickness difference (J≠K) design can accelerate the directional heat conduction and avoid phase distortion of high-frequency signals due to temperature rise. At the same time, when the required synthesized signal is a high-power microwave signal, the instantaneous high-power pulse generates a severe temperature rise, requiring dynamic thermal management to prevent device burnout. The offset of the thermally conductive component 301 induced by the dielectric layer thickness difference can adaptively adjust the heat conduction path and improve the heat dissipation response speed.

[0054] Specifically, in this embodiment, the first dielectric layer 303 and the second dielectric layer 304 are made of the same ceramic material, where J / K ≤ 1 / 4. When the merging node 201 generates heat and is conducted to the inner cavity through the heat conductor 301, the second dielectric layer 304 generates a local temperature gradient, causing the heat conductor 301 to shift. The heat from the merging node 201 is then conducted to the heat sink 31 for dissipation through the first dielectric layer 303 and the second dielectric layer 304. Using the same ceramic material for both dielectric layers ensures that they have consistent dielectric constant temperature coefficient and thermal expansion coefficient, avoiding thermal stress at the interface of dissimilar materials. This improves the stability of high-frequency signal transmission and reduces electromagnetic performance degradation caused by material thermal deformation. The defined thickness difference creates a significant difference in thermal resistance, amplifying the temperature gradient and accelerating heat accumulation in the thicker second dielectric layer 304, triggering the shift response of the heat conductor 301 and improving heat dissipation efficiency. Specifically, the high-frequency signal superposition at the combining node 201 generates heat, which is conducted to the inner cavity of the heat dissipation structure 30 through the heat conductor 301. The first dielectric layer 303 is thin and has low thermal resistance, allowing heat to quickly penetrate to the ground layer. The second dielectric layer 304 is thick and has high thermal resistance, causing heat to accumulate within it and form a high-temperature region. Due to its high thermal resistance, the second dielectric layer 304 has a significantly higher temperature than the first dielectric layer 303. The dielectric constant of the ceramic material decreases with increasing temperature, and the decrease is more pronounced in the second dielectric layer 304, creating a dielectric constant gradient. This gradient leads to an uneven electric field distribution, generating an electromagnetic force pointing towards the second dielectric layer 304, which pushes the heat conductor 301 towards the second dielectric layer 304. After the heat-conducting component 301 is offset, the contact area with the second dielectric layer 304 increases. Heat is temporarily stored through the high thermal capacity of the second dielectric layer 304 and quickly conducted to the outer shell 10 through the first dielectric layer 303. The high thermal resistance of the second dielectric layer 304 delays the return of heat to the merging node 201, forming a "thermal buffer". The selection of the thickness ratio J / K needs to be optimized by multiphysics simulation in combination with the thermal conductivity, temperature coefficient of dielectric constant of ceramic material and electromagnetic coupling model of heat-conducting component 301. The thickness ratio proposed in the embodiment is an extreme thickness difference based on the dielectric constant and thermal conductivity of ceramic material, in order to cope with the problem that the instantaneous heat generated during high-power pulsed microwave merging may cause thermal breakdown of the device.

[0055] In this application, after the first dielectric layer 303 and the second dielectric layer 304 expand due to heat, they cool down at the subsequent junction node 201 and return to their original state. As a result, after the first dielectric layer 303 and the second dielectric layer 304 cool down, their volumes will return to their original state so that they can be used next time.

[0056] It should be noted that, in this embodiment, ceramic is used as an example. Ceramics are composed of atoms bonded by ionic / covalent bonds, and their physical properties stem from the anharmonicity of interatomic forces. When the temperature rises, the thermal vibrations of the atoms (or ions) constituting the ceramic intensify, leading to an increase in their average spacing, which macroscopically manifests as volume expansion. This expansion process is mainly determined by the anharmonicity of the interatomic bonding forces and falls within the category of reversible elastic deformation. When the temperature is uniformly reduced to the initial temperature, the atomic thermal vibration energy weakens, and under the influence of interatomic bonding forces (mainly manifested as attractive forces), it spontaneously tends to return to its original equilibrium spacing, thereby achieving macroscopic dimensional restoration. Therefore, when its merging node 201 cools down, its volume can return to its original state for future use. It is understood that "returning to its original state" here refers to a volume relative to the expanded volume; after repeated long-term use, the volume may be larger than the initial volume before expansion. The principle of a similar dielectric layer is similar and will not be explained further here.

[0057] Specifically, in this embodiment, the first dielectric layer 303 is a ceramic plate, and the second dielectric layer 304 is a foam board. The thickness of the first dielectric layer is defined as J, and the thickness of the second dielectric layer is defined as K, where J = K. The first dielectric layer 303, being a ceramic plate, provides the heat dissipation structure 30 with a high dielectric constant and thermal conductivity. Typically, the dielectric constant of ceramics is 9-10. As a substrate for the dielectric layer, the ceramic material supports signal transmission while quickly dissipating some heat. The second dielectric layer 304, being a foam board, is essentially a foam board filled with ceramic particles. Its dielectric constant is low. Utilizing the low dielectric constant and thermal insulation properties of the foam material, a dielectric constant difference and thermal resistance barrier are formed between the foam material and the first dielectric layer 303 within the heat dissipation structure 30. This difference in thermal response drives the thermal conductive component 301 to shift, while simultaneously reducing heat conduction loss to the foam layer. In this embodiment, the thickness J = K is defined to balance the physical properties of ceramics and foam, avoid introducing structural stress due to thickness differences, simplify the manufacturing process, and improve structural reliability.

[0058] When a large amount of heat is generated at the merging node 201 and transferred to the heat dissipation structure 30, the ceramic plate of the first dielectric layer 303, due to its good thermal conductivity, can quickly absorb the heat, causing its temperature to rise rapidly and its dielectric constant to decrease significantly. The temperature rise of the foam plate of the second dielectric layer 304 is slower, and its dielectric constant changes less. Due to its material properties, the change in dielectric constant is close to zero or positive. Because the decrease in dielectric constant of the ceramic layer is much greater than that of the foam layer, a dielectric gradient is formed, causing the electric field lines to concentrate on the side with higher dielectric constant, generating an electrostatic force pointing towards the foam layer. The electrostatic force pushes the heat-conducting component 301 to shift towards the foam layer until it is in contact with it, increasing the contact area with the foam layer. The heat is quickly conducted to the outer shell 10 through the ceramic plate, and the foam plate, due to its low thermal conductivity, forms a thermal barrier, reducing the diffusion of heat to non-heat dissipation areas.

[0059] Specifically, in this embodiment, the first dielectric layer 303 is a ceramic plate, and the second dielectric layer 304 is a foam plate. The thickness of the first dielectric layer is defined as J, and the thickness of the second dielectric layer is defined as K, where J≠K. The first dielectric layer 303, being a ceramic plate, provides high thermal conductivity and high-frequency signal stability, quickly dissipates heat and maintains electromagnetic field uniformity, ensuring low signal transmission loss and avoiding phase distortion caused by temperature rise. The second dielectric layer 304, being a foam plate, forms a thermal resistance barrier and a dielectric driving source. It amplifies the dielectric constant gradient through thermal response differences, driving the thermal conductive component 301 to dynamically shift and optimize the heat dissipation path. By adjusting the thermal conductivity rate and dielectric constant variation amplitude through the thickness difference of heterogeneous materials, an asymmetric thermal field is formed, enhancing the shifting driving force of the thermal conductive component 301, while balancing the differences in physical properties (such as the coefficient of thermal expansion) between ceramic and foam. The foam layer, due to its low thermal conductivity, forms a thermal buffer, delaying the return of heat to sensitive areas (such as the merging node 201), improving heat dissipation efficiency and protecting the device.

[0060] In one specific embodiment, the heat dissipation shell 31 has an electric field concentrating groove 31b, which is a blind hole. The direction from the merging node 201 to the heat dissipation structure 30 is defined as the first direction X, and the electric field concentrating groove 31b extends from the merging node 201 along the first direction X. The length of the electric field concentrating groove 31b along the first direction X is defined as B, and the wavelength of the synthesized microwave is defined as λ, where B = λ / 4.

[0061] It should be noted that, since the inner cavity of the heat sink 31 is filled with conductive medium 302, in order to prevent the conductive medium 302 from overflowing, this embodiment sets the electric field concentration groove 31b as a blind hole, that is, the electric field concentration groove 31b does not penetrate the heat sink 31, thereby preventing the problem of conductive medium 302 overflowing due to the opening of the groove.

[0062] Furthermore, in the microwave synthesizer 100 of this embodiment, the wavelengths of the microwaves input to each microwave input port are all equal (λ). During the microwave synthesis process, when the microwaves propagate through each combining unit 20 to the combining node 201, the microwaves are transmitted through the combining node 201 to the electric field concentration slot 31b and reach the voltage standing wave peak position at the slot opening of the electric field concentration slot 31b to form the maximum electric field, thereby generating an electric field force to drive the heat-conducting component 301 to move towards the second dielectric layer 304 until it adheres to the second dielectric layer 304. The specific derivation process is as follows:

[0063] In this embodiment, the electric field concentrating slot 31b can be understood as a slit of length B (which can be understood as a microstrip line branch with characteristic impedance Z0). The bottom of the electric field concentrating slot 31b is in contact with the heat sink 31 and short-circuited, while the slot opening of the electric field concentrating slot 31b is an open-circuit structure. In this branch, its phase constant is: Among them, the waveguide wavelength of this structure Therefore, the instantaneous voltage distribution on this branch can be written in standing wave form: V(x) = V + e -jβx +V - e +jβx At the short-circuit break (the bottom of the electric field concentration tank 31b, which can be defined as X = 0), its voltage is 0, where,

[0064] At the open circuit end (i.e., the slot opening of the electric field concentration slot 31b, defined as X = A), the current is 0, and the corresponding voltage standing wave is at its peak value, as detailed below:

[0065]

[0066] When I(A) = 0, substitute into V - =-V + ,available:

[0067]

[0068] After sorting, we get:

[0069] At this point, taking n=0, we get Right now

[0070] Therefore, it can be deduced that when B = λg / 4, the slot is located at the peak of the voltage standing wave to form the maximum electric field. At this time, the heat-conducting component 301 is driven to the second dielectric layer 304 for heat dissipation under the action of the electric field force.

[0071] It should be noted that, since this application is used in a microwave combiner, and during the microwave combining process, multiple microwaves of the same wavelength need to be transmitted in a microstrip line, an electric field is generated during microwave transmission. Therefore, this application connects the heat dissipation structure 30 to the microwave transmission combining node 201, so that the microwaves are transmitted to the heat dissipation structure 30 through the combining node 201. In conjunction with the electric field concentration slot 31b, the electric field is concentrated at the slot opening, thereby generating a spontaneous electric field force to drive the heat-conducting component 301 to move. Compared to the prior art which uses an external electric field, this application avoids the connection of an external electric field and fully utilizes the properties of microwaves in the microwave combiner, reducing the manufacturing and usage costs of the equipment.

[0072] Furthermore, in order to facilitate better driving of the heat-conducting component 301 to fit the second dielectric layer 304, in a specific embodiment, the middle end 3012 of the heat-conducting component 301 has a first surface 301a facing the first dielectric layer 303, the electric field concentrating groove 31b is formed on the first dielectric layer 303, and the heat-conducting component 301 has a second surface 301b facing the second dielectric layer 304;

[0073] The first surface 301a is coated with a first copper foil electrode layer 301c, and the second surface 301b is coated with a second copper foil electrode layer 301d. A first capacitor is formed between the first copper foil electrode layer 301c and the first dielectric layer 303 to concentrate an electric field. A second capacitor is formed between the second copper foil electrode layer 301d and the second dielectric layer 304 to generate an electric field force together with the first capacitor to drive the movement of the heat-conducting component.

[0074] It should be noted that X is defined as the displacement of the heat-conducting component 301 relative to the initial levitation center in the direction of the second dielectric layer 304. In the initial state, X = 0, and the distances of the heat-conducting component 301 from the first dielectric layer 303 and the second dielectric layer 304 are both d0;

[0075] Therefore, the first capacitor is Where ε1 is the dielectric constant of the first dielectric layer 303, and A is the area of ​​the plate;

[0076] The second capacitor is Where ε2 is the dielectric constant of the second dielectric layer 304, at which time, the slot resonance generates a local voltage V, which is applied between the first copper foil electrode layer 301c and the second copper foil electrode layer 301d.

[0077] Therefore, the first capacitor and the second capacitor are connected in parallel, and the total capacitance is:

[0078] C total (x) = C1(x) + C2(x);

[0079] The stored electrical energy is:

[0080]

[0081] Therefore, the electrostatic driving force is the negative derivative of electrical energy with respect to displacement:

[0082]

[0083] The derivative of the first capacitance is:

[0084]

[0085] The derivative of the second capacitor is:

[0086]

[0087] By combining, we get:

[0088]

[0089] Based on the above formula, it can be seen that when the heat-conducting component 301 is in the initial floating position, i.e., X = 0,

[0090]

[0091] therefore, Substitution We can obtain:

[0092]

[0093] If ε2 > ε1, then Therefore, it can be concluded that F(0) < 0, and the heat-conducting component 301 is driven by the electric field.

[0094] The device moves to the second dielectric layer 304 until it adheres to the second dielectric layer 304.

[0095] Specifically, in this embodiment, the microwave combiner 100 further includes a heat transfer element 305. One end of the heat transfer element 305 is disposed on the heat conductor 301, and the other end is disposed on the outer casing 10, for transferring heat from the heat conductor 301 to the outer casing 10. One end of the heat transfer element 305 is disposed on the heat conductor 301, directly capturing the heat generated by the heat conductor 301, establishing an auxiliary heat dissipation path from the heat conductor 301 to the outer casing 10, reducing the local temperature rise of the heat conductor 301, and avoiding signal attenuation or component damage due to overheating; the other end of the heat transfer element 305 is disposed on the outer casing 10, efficiently conducting heat to the surface of the outer casing 10, using the outer casing 10 as a heat dissipation terminal to exchange heat with the environment, enhancing the overall heat dissipation capacity, reducing thermal resistance, and improving the reliability of the combiner in high-temperature environments. The heat transfer element 305 serves as a supplementary heat channel independent of the heat dissipation structure 30, forming a dual-path heat dissipation mechanism with the main heat dissipation path (dielectric layer heat conduction): the main path—heat passes through the heat transfer element 301 → conductive medium 302 → dielectric layer → outer shell 10; the auxiliary path—heat passes through the heat transfer element 305 → outer shell 10; thus achieving heat load distribution, with the main heat dissipation path (dielectric layer) dominating heat dissipation, and the heat transfer element 305 serving as a backup path to prevent system overheating due to the failure of a single heat dissipation path, improving redundancy safety. The heat transfer element 305 also handles more heat, preventing thermal runaway due to overload of the main path. The merging node 201 generates heat due to the superposition of high-frequency signals, and the heat is transferred to the connection point of the heat transfer element 305 through the heat transfer element 301. The heat transfer element 305 uses a highly thermally conductive material (such as copper, aluminum, or graphene) to quickly absorb the heat from the heat transfer element 301, and the heat is conducted longitudinally along the heat transfer element 305 to the outer shell 10, preventing heat accumulation around the heat transfer element 301. When high-power multi-band combined circuits need to operate for a long time, the heat transfer element 305 needs to quickly dissipate heat to prevent the power amplifier chip (PB) from being damaged due to temperature rise.

[0096] In one specific embodiment, the heat transfer element 305 includes an elastic pad 306 and fins 307. The elastic pad 306 is disposed on the first end 3011 for connection to the heat conduction element 301. The fins 307 are disposed on the second end 3013 for connection to the outer casing 10. It is understood that the fins 307 can be connected to the outer casing via a heat sink.

[0097] In one specific embodiment, the heat transfer element 305 is a base structure.

[0098] It should be noted that the heat transfer component 305 mentioned above is a relatively conventional heat dissipation component in the prior art, and will not be discussed in detail here.

[0099] Specifically, in this embodiment, the conductive medium 302 is filled with ceramic particles, which are uniformly dispersed in the inner cavity 31a to enhance the heat transfer efficiency from the heat-conducting component 301 to the heat sink. The ceramic particles (such as alumina or aluminum nitride) serve as high thermal conductivity fillers, embedded in the conductive medium 302, and can construct a multi-path heat transfer network, improving the overall thermal conductivity of the medium. The particles are in direct contact with the heat-conducting component 301 and the heat sink, forming a short-path heat transfer path of "heat-conducting component 301 → particles → heat sink," which reduces the thermal resistance between the heat-conducting component 301 and the heat sink, significantly improving heat dissipation efficiency.

[0100] Specifically, in this embodiment, a copper foil is provided outside the grounding layer of the heat dissipation structure 30 to conduct heat from the grounding layer. In the heat dissipation structure, the grounding layer is actually the side of the dielectric layer that does not contact the conductive medium. By providing a copper foil covering the surface of the grounding layer, the heat accumulated in the grounding layer can be quickly conducted to the outer casing, preventing the electromagnetic shielding performance from deteriorating due to the grounding layer heating up.

[0101] Example 2

[0102] This second embodiment provides a microwave device, including the microwave combiner from the first embodiment.

[0103] It should be noted that the microwave combiner in the microwave equipment in this embodiment two is exactly the same as that in embodiment one, and therefore has the same beneficial effects, which will not be repeated here.

[0104] The above description is merely an embodiment of this application. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of this application, but these improvements all fall within the protection scope of this application.

Claims

1. A microwave combiner, characterized by The application relates to a microwave synthesizer. The microwave synthesizer comprises a shell enclosed by a full-enclosed metal cavity; At least two combining units, each of which is connected by a stripline, and at least two of the combining units meet at a combining node; A heat dissipation structure is arranged in the shell, and the heat dissipation structure comprises a heat dissipation shell and a heat conduction piece. The heat dissipation shell is attached to the shell on the side surface. The heat conduction piece comprises a first end, a middle end and a second end which are connected in sequence along the length direction of the heat conduction piece. The first end is connected to the stripline of the combining node. The second end extends out of the heat dissipation shell and is attached to the shell. The heat dissipation shell is provided with an inner cavity which is filled with a conductive medium. The middle end is suspended in the conductive medium. When the heat generated by microwave synthesis exceeds a threshold value at the combining node, the middle end is offset so that the side surface of the middle end is attached to the heat dissipation shell, so that the heat is dissipated through the heat dissipation shell and the shell.

2. The microwave hybrid according to claim 1, wherein, The heat dissipation shell comprises a first dielectric layer and a second dielectric layer which are arranged oppositely and attached to the shell. When the combining node generates heat and the heat is conducted to the inner cavity through the heat conduction piece, the dielectric constant of the first dielectric layer and the second dielectric layer is changed, so that the heat conduction piece is driven to be offset. The heat of the combining node is conducted to the heat dissipation shell through the first dielectric layer and the second dielectric layer to be dissipated.

3. The microwave hybrid according to claim 2, wherein, The heat dissipation shell is provided with an electric field concentration groove which is arranged on the first dielectric layer. The electric field concentration groove is a blind hole. The direction of the combining node pointing to the heat dissipation structure is defined as a first direction. The electric field concentration groove extends from the combining node along the first direction. In the first direction, the length of the electric field concentration groove is defined as B, and the wavelength of the synthesized microwave is defined as lambda. B = lambda / 4.

4. The microwave hybrid according to claim 3, wherein, The middle end of the heat conduction piece has a first surface opposite to the first dielectric layer, and a second surface opposite to the second dielectric layer. The first surface is coated with a first copper foil electrode layer, and the second surface is coated with a second copper foil electrode layer. A first capacitor is formed between the first copper foil electrode layer and the first dielectric layer for gathering an electric field. A second capacitor is formed between the second copper foil electrode layer and the second dielectric layer for generating an electric field force together with the first capacitor to drive the middle end of the heat conduction piece to move.

5. The microwave hybrid according to claim 2, wherein, The first dielectric layer and the second dielectric layer are made of the same dielectric constant material. The thickness of the first dielectric layer is defined as J, and the thickness of the second dielectric layer is defined as K. J is not equal to K.

6. The microwave hybrid according to claim 5, wherein, The first dielectric layer and the second dielectric layer are made of the same metal material. J / K <= 1 / 4. When the combining node generates heat and the heat is conducted to the inner cavity through the middle end, the heat conduction piece is heated, the dielectric constant of the first dielectric layer and the second dielectric layer is changed, and the heat conduction piece is driven to be offset.

7. The microwave hybrid according to claim 2, wherein, The first dielectric layer is a copper plate, the second dielectric layer is an aluminum plate, the thickness of the first dielectric layer is defined as J, the thickness of the second dielectric layer is defined as K, wherein J=K, when the combining node generates heat and conducts to the inner cavity through the heat conducting member, the heat conducting member is heated, the dielectric constant of the first dielectric layer and the second dielectric layer is changed, so as to drive the heat conducting member to deviate.

8. The microwave hybrid according to claim 2, wherein, The microwave combiner further comprises a heat transfer member, one end of the heat transfer member is arranged on the heat conducting member, and the other end of the heat transfer member is arranged on the shell, and the heat transfer member is used for transferring the heat of the heat conducting member to the shell.

9. The microwave hybrid according to claim 8, wherein, The heat transfer member is a seat body structure.

10. A microwave device, characterized by The microwave combiner comprises the microwave combiner according to any one of claims 1-9.

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