Radar passive heat dissipation structure

Abstract

This application provides a passive heat dissipation structure for radar, comprising an antenna radome, a front-end assembly, a mid-end assembly, and a rear-end assembly arranged sequentially. The front-end assembly includes a front-end heat dissipation frame, a power amplifier board, and a phase-change heat storage module. First heat dissipation teeth are vertically arranged on both sides of the front-end heat dissipation frame. The front-end heat dissipation frame includes a first intermediate layer, within which a first graphite layer with a concave bending structure is disposed; and its two ends extend to the root of the corresponding first heat dissipation teeth. The power amplifier chip is tightly attached to the bottom surface of the first intermediate layer via a thermal pad. The phase-change heat storage module is tightly attached to the top surface of the first intermediate layer via a thermal pad. The structure provided by this invention achieves effective heat dissipation for both low duty cycle operating modes and short-term high duty cycle operating modes without increasing the system size.

Description

Technical Field

[0001] This invention relates to the field of thermal management of radar electronic equipment, and more particularly to a passive heat dissipation structure for radar. Background Technology

[0002] The radar integrates high-power amplifier chips, high-speed signal processing chips, and other high-heat-flux-density devices. The entire unit operates under two typical conditions: a low duty cycle mode and a short-duty cycle mode. During operation, the high-power processing chips at the back end are essentially at their rated normal operating conditions in both modes, resulting in relatively high and concentrated heat dissipation. In the low duty cycle mode, the heat dissipation of the front-end amplifier chip is relatively low, while in the high duty cycle mode, the heat dissipation of the front-end amplifier chip is relatively high.

[0003] However, existing radar heat dissipation technologies generally suffer from the following structural defects: Existing radar heat dissipation technologies can largely solve the heat dissipation problem in low duty cycle operation modes. However, when the radar operates in a high duty cycle state, due to its high heat dissipation, solving the heat dissipation problem requires the system to rely on forced air cooling. Additional components such as fans increase the overall system size, and the reliability of moving parts like fans is low, failing to meet the requirements of high integration and high reliability. Furthermore, the high duty cycle operation mode is short-lived; therefore, effective heat dissipation of the radar needs to be achieved in a short time.

[0004] In summary, how to effectively dissipate heat in both low duty cycle and short-term high duty cycle operating modes without increasing the system size has become an urgent problem to be solved. Summary of the Invention

[0005] This invention provides a passive heat dissipation structure for radar, which solves the shortcomings of existing technologies that cannot simultaneously achieve both size and effective heat dissipation in both operating states.

[0006] This application provides a passive heat dissipation structure for radar, comprising an antenna radome, a front-end assembly, a mid-end assembly, and a rear-end assembly arranged sequentially. The front-end assembly includes a front-end heat dissipation frame, a power amplifier board, and a phase change thermal storage module; The front-end heat dissipation frame includes a first intermediate layer made of aluminum alloy, and the first intermediate layer has a hollow structure. First heat dissipation teeth are vertically arranged on both sides of the front heat dissipation frame, with the openings of the first heat dissipation teeth facing outwards. A first graphite layer is disposed within the first intermediate layer; the first graphite layer has a concave bending structure, and its two ends extend to the root of the corresponding first heat dissipation tooth; The power amplifier board has a power amplifier chip on top, and the power amplifier chip is in close contact with the bottom surface of the first intermediate layer through a thermal pad; the phase change heat storage module is in close contact with the top surface of the first intermediate layer through a thermal pad.

[0007] Preferably, in the radar passive heat dissipation structure described above, the mid-end assembly includes a mid-end heat dissipation frame, a first heat-generating module, and a second heat-generating module. The mid-range heat dissipation frame includes a second intermediate layer made of aluminum alloy, and the second intermediate layer has a hollow structure. A second heat dissipation tooth is vertically arranged on both sides of the middle heat dissipation frame, with the opening of the second heat dissipation tooth facing outward; A second graphite layer is provided inside the second intermediate layer. The second graphite layer has a concave bending structure, and its two ends extend to the root of the corresponding second heat dissipation tooth. The first heating module and the second heating module are respectively attached to the top and bottom surfaces of the second intermediate layer via thermal pads.

[0008] Preferably, in the radar passive heat dissipation structure described above, the back-end assembly includes: a back-end heat dissipation frame and a processing board; A third row of heat dissipation teeth is horizontally arranged on the top surface of the rear heat dissipation frame; The rear heat dissipation frame includes a third intermediate layer made of aluminum alloy, and the third intermediate layer has a hollow structure. A third graphite layer is disposed within the third intermediate layer. The third graphite layer has a planar sheet structure and its size is adapted to the size of the third heat dissipation tooth. The processing board has a high-power processing chip, which is attached to the bottom surface of the third intermediate layer via a thermal pad.

[0009] Preferably, in the radar passive heat dissipation structure described above, the rear-end assembly is detachably connected to the middle-end assembly.

[0010] Compared with the prior art, the beneficial effects of the present invention are: The concave, high-thermal-conductivity graphite layers of the front-end and mid-end heat dissipation frames are continuous structures, extending the efficient planar heat conduction of the graphite layer into three-dimensional heat conduction. This directly transfers internal system heat to the roots of the heat dissipation teeth on both sides of the frame, significantly improving the heat dissipation efficiency of the front and mid-end. The graphite layer of the rear-end heat dissipation frame is planar. Since the high-power processing chips on the processing board have relatively concentrated heat, the efficient thermal expansion capability of the graphite layer reduces heat concentration, improving the heat dissipation capacity of the rear end. Passive cooling is sufficient for low duty cycle operation, resulting in high integration and reliability. The power amplifier board and phase-change thermal storage module are respectively attached to the two sides of the middle layer of the front-end heat dissipation frame. During high duty cycle operation, the power amplifier chip has high heat dissipation, and passive cooling cannot meet the heat dissipation requirements. Excess heat is transferred through the graphite layer to the phase-change thermal storage module, resolving the short-term high duty cycle operation of the system.

[0011] In summary, this application employs a composite solution that enhances the basic passive heat dissipation capability through a concave bent three-dimensional graphite layer and buffers short-term peak heat loads by arranging phase change thermal storage modules on both sides. The entire process uses purely passive heat dissipation, eliminating additional components such as fans and not increasing the overall system size. It simultaneously meets the heat dissipation requirements of both long-term low duty cycle and short-term high duty cycle radar operating conditions, taking into account equipment integration, long-term operational reliability, and thermal control effect under all operating conditions.

[0012] The multi-layer heat dissipation structure is connected in series, resulting in high integration and good maintainability. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 A three-dimensional schematic diagram of the radar passive heat dissipation structure provided in this application; Figure 2 A schematic cross-sectional view of the radar passive heat dissipation structure provided in this application; Figure 3 A schematic cross-sectional view of the front end assembly of the radar passive heat dissipation structure provided in this application; Figure 4 A schematic cross-sectional view of the mid-section of the radar passive heat dissipation structure provided in this application; Figure 5 A schematic cross-sectional view of the rear end assembly of the radar passive heat dissipation structure provided in this application; Figure label: 1. Antenna radome; 2. Front-end assembly; 3. Mid-end assembly; 4. Rear-end assembly; 5. Thermal pad; 21. Front-end heat dissipation frame; 22. Power amplifier board; 23. Phase change thermal storage module; 211. First graphite layer; 212. First heat dissipation fin; 213. First intermediate layer; 221. Power amplifier chip; 31. Mid-range heat dissipation frame; 32. First heat dissipation module; 33. Second heat dissipation module; 311. Second graphite layer; 312. Second heat dissipation tooth; 313. Second intermediate layer; 41. Rear heat dissipation frame; 42. Processing board; 411. High thermal conductivity graphite layer; 412. Third heat dissipation tooth; 413. Third intermediate layer; 421. Processing chip. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0016] Please see Figure 1-3 The radar passive heat dissipation structure provided in this application includes an antenna radome 1, a front-end assembly 2, a middle assembly 3, and a rear-end assembly 4 arranged sequentially. The front-end assembly 2 includes a front-end heat dissipation frame 21, a power amplifier board 22, and a phase change heat storage module 23. The front-end heat dissipation frame 21 includes a first intermediate layer 213 made of aluminum alloy, which is a hollow structure. First heat dissipation teeth 212 are vertically arranged on both sides of the front-end heat dissipation frame 21, with the openings of the first heat dissipation teeth 212 facing outwards. A first graphite layer 211 is arranged inside the first intermediate layer 213. The first graphite layer 211 has a concave bending structure, and its two ends extend to the root of the corresponding first heat dissipation teeth 212. A power amplifier chip 221 is arranged on the top of the power amplifier board 22, and the power amplifier chip 221 is in close contact with the bottom surface of the first intermediate layer 213 through a thermal pad 5. The phase change heat storage module 23 is in close contact with the top of the first intermediate layer 213 through a thermal pad 5.

[0017] Specifically, the front-end heat dissipation frame 21 of the radar passive heat dissipation structure provided in this application is made of aluminum alloy, with a hollow interior forming a first intermediate layer 213; the left and right sides of the frame are vertically arranged with outward-facing first heat dissipation teeth 212, which serve as the heat dissipation surface for final convection heat exchange with the air. The aluminum alloy substrate serves as structural support, auxiliary heat conduction, and a container for the graphite layer, while the hollow interlayer provides installation space for the highly thermally conductive first graphite layer.

[0018] The first graphite layer 211 is embedded inside the hollow first intermediate layer 213 of aluminum alloy and adopts a concave bending integrated continuous structure. The two ends after bending directly extend and fit to the roots of the first heat dissipation teeth 212 on both sides. This application achieves a three-dimensional heat conduction path by bending the first graphite layer 211, so that heat can be directly conducted from the middle heat source area to the roots of the heat dissipation teeth on both sides, thereby shortening the heat conduction path.

[0019] The power amplifier chip 221 is tightly attached to the bottom surface of the first intermediate layer 213 of aluminum alloy through the thermal pad 5, and the phase change heat storage module 23 is attached to the top surface of the first intermediate layer 213 of aluminum alloy through the thermal pad 5. The two share the same set of graphite uniform temperature conduction channels, forming a symmetrical layout with continuous heat generation on one side and heat storage on demand on the other side.

[0020] The following describes the radar's operating process under two different conditions: Operating Condition 1: Radar operates at a low duty cycle for extended periods. When the radar operates at a low duty cycle, the heat generated by the power amplifier chip 221 is transferred to the front-end heat dissipation frame 21 through the thermal pad 5, and then quickly transferred to the first heat dissipation tooth 212 through the concave bent, highly thermally conductive first graphite layer 211, before being passively dissipated into the air. Because the heat dissipation of the power amplifier chip 221 is relatively low when the radar operates at a low duty cycle, the temperature of the middle layer of the front-end heat dissipation frame 21 is low enough to cause a phase change in the phase change heat storage module 23. Therefore, the phase change heat storage module 23 is not activated, and the temperature is stably controlled solely by the purely passive heat dissipation of the first graphite layer, aluminum frame, and first heat dissipation tooth.

[0021] Operating Condition 2: Radar operates at a short-term high duty cycle When the radar switches from long-duty-cycle low-duty-cycle operation to short-duty-cycle high-duty-cycle operation, the heat generated by the power amplifier chip 221 is transferred to the front-end heat dissipation frame 21 through the thermal pad 5. Some of the heat is quickly transferred to the first heat dissipation tooth 212 through the concave bent high thermal conductivity first graphite layer 211, and then passively dissipated into the air. Since the heat generated by the power amplifier chip 221 in the high-duty-cycle state is much higher than that in the low-duty-cycle state, the passive heat dissipation method is insufficient to meet the heat dissipation requirements at the current temperature, and the power amplifier chip 221 continues to heat up. The front-end heat dissipation frame 21 and the phase change heat storage module 23 also heat up accordingly. When the temperature reaches the phase change critical point of the phase change heat storage module 23, the phase change material of the phase change heat storage module 23 changes from solid to liquid, absorbing the remaining heat, thereby suppressing the chip temperature surge and ensuring that the system remains basically stable.

[0022] This application can also design a heat dissipation structure that meets different high duty cycle states by reasonably designing the working time and heat consumption of the high duty cycle state, as well as the heat storage and phase change temperature of the phase change heat storage module 23.

[0023] Operating Condition 3: Switching from high duty cycle to low duty cycle When the radar switches from short-duty cycle high-duty cycle operation to long-duty cycle low-duty cycle operation, the heat generated by the power amplifier chip 221 is transferred to the front-end heat dissipation frame 21 through the thermal pad 5, and then quickly transferred to the first heat dissipation tooth 212 through the concave bending high thermal conductivity first graphite layer 211, and finally transferred to the air through passive heat dissipation. Since the heat generated by the power amplifier chip 221 in the low-duty cycle state is much lower than that in the high-duty cycle state, the power amplifier chip 221 cools down rapidly, and the front-end heat dissipation frame 21 and the phase change heat storage module 23 also cool down accordingly. When the temperature reaches the phase change critical point of the phase change heat storage module 23, the phase change material of the phase change heat storage module 23 changes from liquid to solid, releasing excess heat. The heat is transferred to the front-end heat dissipation frame 21 through the thermal pad 5, and then quickly transferred to the heat dissipation tooth 212 through the concave bending high thermal conductivity graphite layer 211, and finally transferred to the air through passive heat dissipation. When the phase change material of the phase change thermal storage module 23 is completely converted into a solid state, the system temperature continues to decrease until it returns to a stable state with a low duty cycle.

[0024] The radar passive heat dissipation structure provided in this application has high thermal resistance because traditional planar graphite can only achieve uniform temperature in a two-dimensional plane. When the heat source and the heat dissipation teeth are not on the same plane, they can only rely on aluminum alloy for slow heat conduction. This application shortens the heat conduction path and greatly improves the heat dissipation efficiency of the front end and middle end by integrally bending and extending the graphite layer 211 to the root of the first heat dissipation tooth.

[0025] The radar passive heat dissipation structure provided in this application does not involve energy storage in the low duty cycle operation state. It relies solely on the first graphite layer and the first heat dissipation teeth for passive heat dissipation. There are no moving parts or fans, resulting in a smaller overall size, lower failure rate, and higher reliability, meeting the requirements of long-term normal operation of the radar. When the radar is in a high duty cycle operation state, the power amplifier chip 221 will generate a large amount of heat in a short period of time. At this time, the phase change heat storage module absorbs the excess heat, preventing the power amplifier chip from malfunctioning due to overheating. The heat absorbed by the phase change heat storage module will be slowly released after switching to a low duty cycle, which is completely within the normal operating temperature range of the chip. This achieves the effect of freely switching between the two operating states while effectively dissipating heat.

[0026] In addition, the radar passive heat dissipation structure provided in this application has separate heat dissipation units connected in series for the radome, front end, middle end and rear end. The front end assembly is an independent module that can be disassembled and installed separately. The power amplifier board and phase change heat storage module are assembled by bonding with thermal pads, without the need for complicated soldering. Faulty components can be replaced individually, making maintenance convenient. At the same time, the capacity of the phase change module, the size of the graphite and the specifications of the heat dissipation teeth can be adjusted according to the radar power to adapt to radars of different power levels.

[0027] Furthermore, the radar passive heat dissipation structure provided in this application has a first heat dissipation tooth arranged vertically with its opening facing outward, which allows the air to directly contact the heat dissipation tooth when the device is working, effectively improving the heat dissipation efficiency.

[0028] The passive heat dissipation structure for radar provided in this application, compared to a single phase change energy storage heat dissipation structure, uses phase change only as a peak buffer. During low duty cycle operation, it relies on passive graphite heat dissipation, thus avoiding the problem of phase change material saturation failure after prolonged operation. Compared to existing air-cooled heat dissipation solutions, it has no moving parts, is smaller in size, and has higher reliability, meeting the high-reliability, maintenance-free application scenarios for radar. Compared to planar graphite heat dissipation structures, the bent three-dimensional graphite layer provided in this application effectively shortens the heat dissipation path and improves heat dissipation efficiency.

[0029] Furthermore, such as Figure 4 As shown, the radar passive heat dissipation structure provided in this application includes a mid-end assembly 3 comprising a mid-end heat dissipation frame 31, a first heat-generating module 32, and a second heat-generating module 33. The mid-end heat dissipation frame 31 includes a second intermediate layer 313 made of aluminum alloy, which is a hollow structure. Second heat dissipation teeth 312 are vertically arranged on both sides of the mid-end heat dissipation frame 31, with the openings of the second heat dissipation teeth 312 facing outwards. A second graphite layer 311 is disposed inside the second intermediate layer 313, which is a concave bending structure, and its two ends extend to the root of the corresponding second heat dissipation teeth 312. The first heat-generating module 32 and the second heat-generating module 33 are respectively attached to the top and bottom surfaces of the second intermediate layer 313 by thermal pads 5.

[0030] The radar passive heat dissipation structure provided in this application improves heat dissipation efficiency by bending and extending the second graphite layer to the roots of the second heat dissipation teeth on both sides, forming a continuous three-dimensional heat conduction channel from the central heat source area of ​​the interlayer directly to the heat exchange surface of the heat dissipation teeth. Furthermore, the heat from the first heating module 32 and the second heating module 33 can be simultaneously transferred to the second graphite layer, which then evenly distributes the heat flow from both layers to all the heat dissipation teeth on both sides, significantly enhancing the overall passive heat dissipation capability of the middle section. Similarly, by vertically arranging the second heat dissipation teeth with their openings facing outwards, hot air flows smoothly and naturally upwards along the tooth gaps, further improving heat exchange efficiency.

[0031] The radar passive heat dissipation structure provided in this application sets the two heat-generating modules on the upper and lower sides of the second intermediate layer, respectively. Compared with the dual-module independent heat dissipation structure with two sets of heat dissipation brackets, it has lower volume, weight and cost.

[0032] Furthermore, such as Figure 5As shown in the radar passive heat dissipation structure above, the rear-end assembly 4 includes: a rear-end heat dissipation frame 41 and a processing board 42; the rear-end heat dissipation frame 41 includes a third intermediate layer 413 made of aluminum alloy, the third intermediate layer 413 having a hollow structure; a third graphite layer 411 is disposed inside the third intermediate layer 413, the third graphite layer 411 having a planar sheet structure; a row of third heat dissipation teeth 412 is horizontally disposed on the top of the third intermediate layer 413; a high-power processing chip 421 is disposed on the bottom surface of the third intermediate layer 413, the high-power processing chip 421 being tightly attached to the third intermediate layer 413 via a thermal pad 5.

[0033] Specifically, the core heat source of the back-end assembly is the high-power processing chip 421. This chip has a high heat flux density and highly concentrated heat, and the entire machine generates heat continuously throughout its operation. Therefore, by placing the high-power processing chip 421 on the outermost layer of the heat dissipation structure and then using the third heat dissipation tooth arranged horizontally on the top surface, the heat can be quickly and effectively carried away. In addition, the planar sheet-like third graphite layer 411, due to its ultra-high in-plane thermal conductivity, allows the heat from a single point on the chip to be quickly and evenly spread across the entire graphite sheet, thereby enabling the heat from the high-power processing chip 421 to be effectively dissipated.

[0034] Furthermore, the dimensions of the third graphite layer 411 match those of the top third heat dissipation tooth 412, with the entire graphite layer covering the projected area of ​​the heat dissipation tooth. This allows heat to be evenly conducted to the roots of all the heat dissipation teeth, avoiding uneven heat transfer loads and wasted heat dissipation area in some areas, thus maximizing the utilization of the convective heat dissipation area. Compared to bent graphite, the planar graphite structure is more suitable for a layout with a single-sided heat source at the rear and heat dissipation at the top. It has no unnecessary bending structure, is simpler to process, has a shorter heat conduction path, and is suitable for a single-layer heat source arrangement at the rear.

[0035] In addition, the rear heat dissipation frame base is also made of aluminum alloy, which has high mechanical rigidity and can stably support the processing board 42, resist vehicle and airborne vibration and impact, and meet the structural reliability requirements of the complex radar operating environment.

[0036] The radar passive heat dissipation structure provided in this application has a rear-end combination of four heat sources with single-sided mounting layout, which is simple in structure, has high space utilization, and is suitable for the rear-end compartment layout.

[0037] The radar passive heat dissipation structure provided in this application consists of an antenna radome 1, a front-end assembly 2, a mid-end assembly 3, and a rear-end assembly 4 arranged sequentially, with the rear-end assembly being an independent and detachable unit; the processing board is assembled solely by relying on thermal pads, without the need for bonding or soldering, and chip failures can be individually disassembled and replaced, making maintenance convenient.

[0038] In addition, this application uniformly uses thermal pads as the interface heat transfer medium, resulting in a high degree of component standardization, reducing the types of parts and lowering production and processing costs.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A passive heat dissipation structure for radar, characterized in that, It includes, in sequence, an antenna radome (1), a front-end assembly (2), a mid-end assembly (3), and a rear-end assembly (4); The front-end assembly (2) includes a front-end heat dissipation frame (21), a power amplifier board (22), and a phase change heat storage module (23). The front heat dissipation frame (21) includes a first intermediate layer (213) made of aluminum alloy, and the first intermediate layer (213) has a hollow structure; First heat dissipation teeth (212) are vertically arranged on both sides of the front heat dissipation frame (21), with the openings of the first heat dissipation teeth (212) facing outwards; A first graphite layer (211) is provided in the first intermediate layer (213); the first graphite layer (211) has a concave bending structure, and its two ends extend to the root of the corresponding first heat dissipation tooth (212); The power amplifier board (22) is provided with a power amplifier chip (221) on its top surface. The power amplifier chip (221) is in close contact with the bottom surface of the first intermediate layer (213) through a heat-conducting pad (5). The phase change heat storage module (23) is in close contact with the top surface of the first intermediate layer (213) through a heat-conducting pad (5).

2. The radar passive heat dissipation structure according to claim 1, characterized in that, The mid-end assembly (3) includes a mid-end heat dissipation frame (31), a first heat dissipation module (32), and a second heat dissipation module (33). The mid-end heat dissipation frame (31) includes a second intermediate layer (313) made of aluminum alloy, and the second intermediate layer (313) has a hollow structure; On both sides of the middle heat dissipation frame (31), a second heat dissipation tooth (312) is vertically provided, and the opening of the second heat dissipation tooth (312) faces outward; A second graphite layer (311) is provided in the second intermediate layer (313). The second graphite layer (311) has a concave bending structure, and its two ends extend to the root of the corresponding second heat dissipation tooth (312). The first heating module (32) and the second heating module (33) are respectively attached to the top and bottom surfaces of the second intermediate layer (313) via thermal pads (5).

3. The radar passive heat dissipation structure according to claim 1, characterized in that, The back-end assembly (4) includes: a back-end heat dissipation frame (41) and a processing board (42). The rear heat dissipation frame (41) includes a third intermediate layer (413) made of aluminum alloy, the third intermediate layer (413) being a hollow structure; a third graphite layer (411) is disposed inside the third intermediate layer (413), the third graphite layer (411) being a planar sheet structure; A row of third heat dissipation teeth (412) is arranged horizontally on the top of the third intermediate layer (413); a high-power processing chip (421) is arranged on the bottom surface of the third intermediate layer (413), and the high-power processing chip (421) is attached to the third intermediate layer (413) by a heat-conducting pad (5).

4. The radar passive heat dissipation structure according to claim 1, characterized in that, The rear assembly (4) is detachably connected to the middle assembly (3).

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