Millimeter wave phased array antenna subarray and adaptive heat dissipation method

Abstract

The application provides a millimeter wave phased array antenna subarray and an adaptive heat dissipation method, which comprises an upper cover plate, an AOP antenna, a shell, a wave control plate and a lower cover plate, the upper cover plate is provided with a heat dissipation structure comprising a primary manifold layer, a secondary manifold layer and a tertiary manifold layer, and the manifold of the tertiary manifold layer is a micron-level diameter manifold obtained by etching.In the application, the upper cover plate of the phased array antenna subarray integrates a main heat dissipation path, so that the thermal resistance is reduced by 35% compared with the traditional bottom heat dissipation, the upper cover plate integrates a micro-channel liquid cooling manifold, the micro-channel is directly photoetched on the back of the chip silicon substrate, the fluid channel is reduced to micron level, the size limitation of the traditional liquid cooling is broken through, and super-compact integration is realized.The application embeds the thermal time constant into the real-time control loop, realizes the heat failure early warning and function degradation instead of hard crash, and realizes the power consumption reduction through the four-step closed loop of manifold heat distribution sensing, mode dynamic adjustment, derating factor calculation and cooling cooperation, so that the power consumption is reduced by more than 40%, the junction temperature control is controlled to be greater than 20 DEG C, and the reliability is improved through MTF multiplication.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of antennas, in particular to a millimeter wave phased array antenna subarray and an adaptive heat dissipation method. BACKGROUND

[0002] With the rapid development of 5G / 6G communication, satellite Internet, millimeter wave radar and military electronic countermeasures, the millimeter wave frequency band (above 24 GHz) has become the core carrier for realizing high-speed data transmission due to its large bandwidth advantage. Phased array antenna technology replaces mechanical rotation with electronic scanning, and has revolutionary advantages in response speed, multi-target tracking and beam flexibility. However, millimeter wave phased array is facing three major challenges:

[0003] 1. High integration bottleneck: millimeter wave wavelength is extremely short (such as 28 GHz wavelength about 10.7 mm), and hundreds or even thousands of antenna elements need to be densely arranged in a limited area, and traditional discrete T / R components occupy a large space and have complex interconnection;

[0004] 2. Heat management dilemma: GaAs / GaN millimeter wave power amplifier chips have high power density, and the spacing between elements is small (usually ≤ λ / 2), which limits the heat dissipation space, and heat accumulation can cause performance drift or even failure;

[0005] 3. RF performance degradation: high-frequency signals are extremely sensitive to transmission paths, and the insertion loss, phase error and channel inconsistency introduced by traditional cable connections can seriously affect beam pointing accuracy and system EIRP (Equivalent Isotropically Radiated Power).

[0006] Current mainstream solutions mostly use multi-layer PCB stacking or silicon-based adapter boards for integration, but there are still problems such as indirect heat dissipation path, sensitive assembly tolerance, and high-frequency interconnection loss. Therefore, an innovative architecture that integrates high-density integration, efficient heat management, and low-loss interconnection is urgently needed to release the full potential of millimeter wave phased array. SUMMARY

[0007] The present application is to solve the heat problem of millimeter wave phased array antenna subarray, and provides a millimeter wave phased array antenna subarray and an adaptive heat dissipation method. The upper cover plate of the phased array antenna subarray integrates the main heat dissipation path, which reduces the thermal resistance by 35% compared with the traditional bottom heat dissipation. The upper cover plate integrates a micro-channel liquid cooling manifold, which directly etches micro-channels on the back of the chip silicon substrate, reduces the fluid channel to microns, breaks through the size limit of traditional liquid cooling, and realizes ultra-compact integration. The present application embeds the thermal time constant into the real-time control loop, realizes the heat failure warning and function degradation instead of hard shutdown, and realizes the power consumption reduction through the four-step closed loop of manifold heat distribution perception → mode dynamic adjustment → derating factor calculation → cooling coordination, which realizes the power consumption reduction of more than 40%, the junction temperature control ΔT> 20℃, and the reliability improvement through MTF multiplication.

[0008] The application provides a millimeter wave phased array antenna subarray, comprising, from top to bottom, an upper cover plate, an AOP antenna, a shell, a wave control plate and a lower cover plate, the AOP antenna comprising N AOP antenna subarrays, N being greater than or equal to 2;

[0009] The upper cover plate comprises an upper cover plate body and a heat dissipation structure connected inside the upper cover plate body;

[0010] The heat dissipation structure comprises, from top to bottom, a first manifold layer, a second manifold layer and a third manifold layer connected inside the upper cover plate body;

[0011] The manifold diameters of the first manifold layer, the second manifold layer and the third manifold layer decrease in turn, the manifold direction of the first manifold layer is different from the manifold direction of the second manifold layer, and the manifold of the third manifold layer is a micron-level diameter manifold obtained by etching, and the micron-level diameter manifold is connected above the chip of the AOP antenna subarray;

[0012] The first manifold layer is a lumped layer covering the full array of the AOP antenna subarray, comprising one input port, K branches and K output ports, and the flow of each branch can be individually controlled;

[0013] The second manifold layer is a regional layer, comprising K branches connected with the K output ports of the first manifold layer respectively, and each branch comprises L manifold channels;

[0014] The third manifold layer is a channel layer, comprising 4N microchannels, every N / 4 microchannels form a group and are connected with one manifold channel, and N / 4 is the product of L and K.

[0015] As a preferred mode, the dynamic control method of the heat dissipation structure is that when the maximum junction temperature T_max of the millimeter wave phased array antenna subarray is less than T_safe, the first manifold layer, the second manifold layer and the third manifold layer are in a uniform flow mode, and each channel has equal flow, and T_safe is a safety temperature threshold;

[0016] When T_safe≤T_max≤T_th, the first manifold layer, the second manifold layer and the third manifold layer are in a hot spot enhancement mode, the manifold at the position of the overheated AOP antenna subarray increases by 20% flow, and T_th is a derating threshold temperature;

[0017] When T_max>T_th, the first manifold layer, the second manifold layer and the third manifold layer are in an emergency bypass mode, the manifold above the AOP antenna subarray with a junction temperature less than T_th is closed, and liquid is supplied to the region where T_max is concentrated.

[0018] The millimeter wave phased array antenna subarray provided by the application is a preferred mode, the manifold direction of the first manifold layer is perpendicular to the manifold direction of the second manifold layer, and the density of the microchannels above the chip of the AOP antenna subarray is doubled.

[0019] K and L are both 4, N is 64, 60% of the total flow is allocated to the first manifold layer, 15% of the total flow is allocated to each branch of the second manifold layer, 0.94% of the total flow is allocated to each channel, and 0.059% of the total flow is allocated to each microchannel; 40% of the total flow is used for system pressure balance, edge area cooling and acting as a bypass.

[0020] The millimeter wave phased array antenna subarray provided by the application is a preferred mode, the first manifold layer controls the flow through a frequency conversion pump, the second manifold layer controls the flow through a proportional regulating valve, and the third manifold layer controls the flow through the layout of the microchannels.

[0021] The millimeter wave phased array antenna subarray provided by the application is a preferred mode, the radio frequency signal lines of the AOP antenna are embedded in different layers of the adapter plate, the radio frequency signals RF1 and RF2 are distributed in the form of a strip line between two layers, and the signals are vertically interconnected through a coaxial structure.

[0022] The AOP antenna and the wave control plate are connected through a radio frequency connector and a radio frequency adapter plate to transmit signals.

[0023] The application provides a self-adaptive heat dissipation method for a millimeter wave phased array antenna subarray, which comprises the following steps:

[0024] S1, collecting the junction temperature data of the millimeter wave phased array antenna subarray in real time, and constructing a temperature distribution map;

[0025] When T_max < T_safe, step S2 is entered;

[0026] When T_safe≤T_max≤T_th, step S3 is entered;

[0027] When T_max > T_th, step S4 is entered;

[0028] S2, the millimeter wave phased array antenna subarray is in a full power mode, the first manifold layer, the second manifold layer and the third manifold layer are in a uniform flow mode, and step S5 is entered;

[0029] S3, the millimeter wave phased array antenna subarray is in a proportional power reduction mode, the power reduction factor is the first manifold layer, the second manifold layer and the third manifold layer are in a hotspot enhancement mode, and step S5 is entered;

[0030] S4, the millimeter wave phased array antenna subarray is in a hierarchical protection mode, a protection level is selected according to an over-temperature region proportion and a temperature rise rate, and antenna power is adjusted, the first manifold layer, the second manifold layer and the third manifold layer are in an emergency bypass mode, and step S5 is entered;

[0031] S5, the wave control board generates wave control instructions, and the wave control instructions are sent to phase shifters and amplifiers for driving, temperature changes are monitored, and step S1 is returned to.

[0032] The adaptive heat dissipation method of the millimeter wave phased array antenna subarray, as a preferred mode, step S4 includes the following steps:

[0033] S41, the millimeter wave phased array antenna subarray is in a hierarchical protection mode, and the first manifold layer, the second manifold layer and the third manifold layer are in an emergency bypass mode;

[0034] If yes, a first protection mode is entered, a channel where T_max of the millimeter wave phased array antenna subarray is located is closed, operating pressure of the heat dissipation structure is increased, and step S5 is entered;

[0035] If no, step S42 is entered;

[0036] S42, if yes, a second protection mode is entered, a scanning angle of the millimeter wave phased array antenna subarray is reduced according to a thermal time constant τ, power is reduced according to a derating factor , and step S5 is entered;

[0037] If no, step S43 is entered;

[0038] S43, a third protection mode is entered, full-array power of the millimeter wave phased array antenna subarray is reduced to 30%, and air cooling is started, and step S5 is entered.

[0039] The adaptive heat dissipation method of the millimeter wave phased array antenna subarray, as a preferred mode, in step S42,

[0040] ;

[0041] Wherein, is a heat capacity, a unit is J / K, and is a product of specific heat capacity and mass of a material; is a thermal conductivity, a unit is W / K, and is 1 / regional thermal resistance.

[0042] The adaptive heat dissipation method of the millimeter wave phased array antenna subarray, as a preferred mode, in steps S3 and S43,

[0043] ;

[0044] wherein, β is the material thermal recession coefficient;

[0045] In steps S3, S4, the actual output power after the system total power consumption is reduced is:

[0046] ;

[0047] wherein, .

[0048] The adaptive heat dissipation method of the millimeter wave phased array antenna subarray has the following advantages:

[0049] ;

[0050] wherein, is the activation energy, is the Boltzmann constant, is the junction temperature, is the junction temperature without using the adaptive heat dissipation method, is the junction temperature after using the adaptive heat dissipation method, is the average aging time without using the adaptive heat dissipation method, is the average aging time without using the adaptive heat dissipation method.

[0051] The present application has the following advantages:

[0052] (1) In the present application, the upper cover plate of the phased array antenna subarray integrates the main heat dissipation path, so that the thermal resistance is reduced by 35% compared with the traditional bottom heat dissipation. The upper cover plate integrates the micro-channel liquid cooling manifold, and the micro-channel is etched on the back of the chip silicon substrate by photolithography, so that the fluid channel is reduced to microns, breaking through the size limitation of traditional liquid cooling and realizing ultra-compact integration. At the same time, the present application adopts a tree-shaped manifold to realize precise on-demand distribution of flow, and directly guides the cooling liquid to the place closest to the heat source (below the chip), realizes "point-to-point" high-efficiency cooling, greatly shortens the heat conduction path, and increases the heat dissipation efficiency.

[0053] (2) The present application proposes a temperature sensing-power adaptive algorithm combined with the wave control board, which embeds the thermal time constant into the real-time control loop to realize thermal failure warning and function degradation instead of hard shutdown, and guarantees the robustness of the system under extreme working conditions. The present application realizes power consumption reduction through four steps of manifold heat distribution sensing, mode dynamic adjustment, reduction factor calculation and cooling cooperation closed loop: more than 40%, junction temperature control ΔT> 20℃, and reliability improvement through MTF multiplication. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 is a structural schematic diagram of a millimeter wave phased array antenna subarray;

[0055] Figure 2 A manifold distribution diagram of a millimeter wave phased array antenna subarray;

[0056] Figure 3 A radio frequency switching schematic diagram of a millimeter wave phased array antenna subarray;

[0057] Figure 4 A flowchart of a millimeter wave phased array antenna subarray and an adaptive heat dissipation method;

[0058] Figure 5 A flowchart of step S4 of a millimeter wave phased array antenna subarray and an adaptive heat dissipation method.

[0059] Reference signs:

[0060] 1, upper cover plate; 11, upper cover plate body; 12, heat dissipation structure; 121, first manifold layer; 122, second manifold layer; 123, third manifold layer; 2, AOP antenna; 3, shell; 4, wave control plate; 5, lower cover plate. DETAILED DESCRIPTION

[0061] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Embodiment 1

[0062] As shown in the drawings, Figures 1-5 A millimeter wave phased array antenna subarray and an adaptive heat dissipation method, the millimeter wave phased array antenna subarray includes an upper cover plate 1, an AOP antenna 2, a shell 3, a wave control plate 4 and a lower cover plate 5 connected in turn from top to bottom, and the AOP antenna 2 includes 64 AOP antenna subarrays;

[0063] The upper cover plate 1 includes an upper cover plate body 11 and a heat dissipation structure 12 connected inside the upper cover plate body 11;

[0064] The heat dissipation structure includes a first manifold layer 121, a second manifold layer 122 and a third manifold layer 123 connected in turn inside the upper cover plate body 11 from top to bottom;

[0065] The manifold diameters of the first manifold layer 121, the second manifold layer 122 and the third manifold layer 123 decrease in turn, the manifold direction of the first manifold layer 121 is different from the manifold direction of the second manifold layer 122, and the manifold of the third manifold layer 123 is a micron-level diameter manifold obtained by etching, and the micron-level diameter manifold is connected above the chip of the AOP antenna subarray;

[0066] The first manifold layer 121 is a lumped layer covering the whole array of the AOP antenna subarray, including one input port, four branches and four output ports, and the flow of each branch can be independently controlled;

[0067] The second manifold layer 122 is a regional layer, including four branches connected with the four output ports of the first manifold layer 121 respectively, and each branch includes four manifold channels;

[0068] The third manifold layer 123 is a channel layer, including 256 micro-channels, and each group of 16 micro-channels is connected with one manifold channel.

[0069] The dynamic control method of the heat dissipation structure 12 is as follows: when the maximum junction temperature T_max of the millimeter wave phased array antenna subarray is less than T_safe, the first manifold layer 121, the second manifold layer 122 and the third manifold layer 123 are in the uniform flow mode, and the flow of each channel is equal, and T_safe is a safety temperature threshold;

[0070] When T_safe≤T_max≤T_th, the first manifold layer 121, the second manifold layer 122 and the third manifold layer 123 are in the hot spot enhancement mode, the manifold at the position of the overheated AOP antenna subarray increases the flow by 20%, and T_th is a derating threshold temperature;

[0071] When T_max>T_th, the first manifold layer 121, the second manifold layer 122 and the third manifold layer 123 are in the emergency bypass mode, the manifold above the AOP antenna subarray with the junction temperature less than T_th is closed, and the liquid is supplied to the region where T_max is located;

[0072] The manifold direction of the first manifold layer 121 is perpendicular to the manifold direction of the second manifold layer 122, and the density of the micro-channels above the chip of the AOP antenna subarray is doubled;

[0073] 60% of the flow is allocated to the core high heat flux area of the first manifold layer 121 (i.e. the chip that needs to be actively cooled), and the other 40% of the flow is used for system pressure balance, edge area cooling and as a bypass. The flow from one first branch is allocated to the four second manifold layers 122 in the region (each sub-region manages 16 channels). The first manifold layer 121 is 60% in total, and is equally divided into four branches, each branch is 15%. Each branch to the second manifold layer 122 is divided into 16 channels, each channel is 0.94%, and to the third manifold layer 123 each channel is further divided into 16 micro-channels, each micro-channel is 0.059%.

[0074] The first manifold layer 121 controls the flow by a frequency conversion pump, the second manifold layer 122 controls the flow by a proportional regulating valve, and the third manifold layer 123 controls the flow by the layout of the micro-channels.

[0075] The radio frequency signal lines of the AOP antenna 2 are embedded in different layers of the adapter plate, and the radio frequency signals RF1 and RF2 are distributed in the form of a strip line structure between two layers, and the signals are vertically interconnected through a coaxial structure.

[0076] The AOP antenna 2 and the wave control board 4 are connected through a radio frequency connector and a radio frequency adapter plate.

[0077] An adaptive cooling method for a millimeter wave phased array antenna subarray includes the following steps:

[0078] S1, real-time acquisition of junction temperature data of the millimeter wave phased array antenna subarray, construction of a temperature distribution map;

[0079] When T_max < T_safe, step S2 is entered;

[0080] When T_safe≤T_max≤T_th, step S3 is entered;

[0081] When T_max > T_th, step S4 is entered;

[0082] S2, the millimeter wave phased array antenna subarray is in full power mode, and the first manifold layer 121, the second manifold layer 122 and the third manifold layer 123 are in uniform flow mode, and step S5 is entered;

[0083] S3, the millimeter wave phased array antenna subarray is in proportional power reduction mode, and the reduction factor is , the first manifold layer 121, the second manifold layer 122 and the third manifold layer 123 are in hotspot enhancement mode, and step S5 is entered;

[0084] S4, the millimeter wave phased array antenna subarray is in a hierarchical protection mode, and the protection level is selected and the antenna power is adjusted according to the over-temperature area ratio and the temperature rise rate, and the first manifold layer 121, the second manifold layer 122 and the third manifold layer 123 are in an emergency bypass mode, and step S5 is entered;

[0085] S4 includes the following steps:

[0086] S41, the millimeter wave phased array antenna subarray is in a hierarchical protection mode, and the first manifold layer 121, the second manifold layer 122 and the third manifold layer 123 are in an emergency bypass mode;

[0087] If the over-temperature area ratio is less than 5%, a first protection mode is entered, the channel where T_max of the millimeter wave phased array antenna subarray is located is closed, and the operating pressure of the heat dissipation structure 12 is increased, and step S5 is entered;

[0088] If not, step S42 is entered;

[0089] S42, judge whether the heating rate is less than 5%, if yes, enter the secondary protection mode, reduce the scanning angle of the millimeter wave phased array antenna subarray according to the thermal time constant τ, reduce the power according to the derating factor , and enter step S5;

[0090] ;

[0091] wherein, is the heat capacity, with the unit of J / K, which is the product of the specific heat capacity of the material and the mass; is the thermal conductance, with the unit of W / K, which is 1 / the area thermal resistance;

[0092] If not, enter step S43;

[0093] S43, enter the tertiary protection mode, the full array power of the millimeter wave phased array antenna subarray is reduced to 30% and the air cooling is started, and enter step S5;

[0094] S5, the wave control board 4 generates wave control instructions, which are issued to the phase shifter and amplifier driver, the temperature change is monitored, and returns to step S1.

[0095] In steps S3 and S43,

[0096] ;

[0097] wherein, β is the material thermal decay coefficient;

[0098] In steps S3 and S4, the actual output power after the system total power consumption is derated is:

[0099] ;

[0100] wherein, .

[0101] The adaptive heat dissipation method judges the heat dissipation effect through MTF:

[0102] ;

[0103] wherein, is the activation energy, is the Boltzmann constant, is the junction temperature, is the junction temperature without using the adaptive heat dissipation method, is the junction temperature after using the adaptive heat dissipation method, is the average aging time without using the adaptive heat dissipation method, is the average aging time without using the adaptive heat dissipation method.

[0104] The upper cover plate of the phased array antenna subarray in the application integrates the main heat dissipation path, so that the thermal resistance is reduced by 35% compared with the traditional bottom heat dissipation. The upper cover plate is integrated with a micro-channel liquid cooling manifold on the outer surface, and the micro-channel is etched on the back of the chip silicon substrate by lithography, so that the fluid channel is reduced to the micron level, breaking through the size limitation of traditional liquid cooling and realizing ultra-compact integration. At the same time, the application adopts a tree-shaped manifold to realize precise on-demand distribution of flow, and directly guides the cooling liquid to the nearest place from the heat source (below the chip), realizes "point-to-point" efficient cooling, greatly shortens the heat conduction path, and increases the heat dissipation efficiency. At the same time, the manifold and the micro-channel radiator are integrated with the electronic packaging structure (such as embedded liquid cooling), reducing the interface thermal resistance and improving the system reliability.

[0105] The application proposes a temperature sensing-power adaptive algorithm combined with a wave control board, embeds a thermal time constant into a real-time control loop, realizes thermal failure warning and function degradation instead of hard shutdown, and guarantees the robustness of the system under extreme working conditions. The application takes the cooling liquid flow and the environment temperature into the real-time thermal resistance calculation, allocates a lower power weight to the channel at the bottom of the stack (near the heat source), actively balances the temperature difference between the layers, and at the same time, recalculates the beam synthesis weight when the channel is closed, so that the EIRP loss is reduced to the theoretical limit. The application realizes power consumption reduction through four steps of closed loop: manifold heat distribution sensing, mode dynamic adjustment, derating factor calculation and cooling cooperation, so that the power consumption is reduced by more than 40%, the junction temperature control ΔT is more than 20℃, and the reliability is improved through MTF multiplication.

[0106] As shown in Figure 1 , the application optimizes the interlayer structure of the radio frequency adapter plate, integrates the core radio frequency front-end function of the Sub-6GHz and millimeter wave double link in a single compact adapter plate, greatly reduces the system volume and weight (more than 50% space can be reduced compared with the discrete scheme), and reduces the material cost and assembly complexity. In order to realize the miniaturization and low profile of the adapter plate, the radio frequency signal line is embedded in different layers of the adapter plate, and the signal is vertically interconnected between layers through a coaxial structure. Figure 3 As shown in , the adapter plate adopted by the application is made of four core plates through two times of pressing, and the radio frequency signals RF1 and RF2 are distributed in the form of strip line between two layers of laminates, and the vertical interconnection is realized through blind and embedded holes between signal layers.

[0107] The application drills through holes in the silicon-based adapter plate, fills conductive materials such as copper / tungsten, realizes vertical conduction between chips, and on the basis of this design, the application realizes three-dimensional space compression through the vertical stacking structure of the antenna-radio frequency-wave control board, saves more than 40% of the installation area compared with the flat layout, and also reduces the structure weight by saving the shell area. No matter from the structure layout or the weight, it is more suitable for scenarios such as satellite and missile.

[0108] The application adopts a modular subarray design, supports multiple unit parallel testing and replacement, greatly improves test efficiency and assembly efficiency. At the same time, the application scheme adopts a radio frequency adapter plate to replace a cable connection, avoids millimeter wave performance fluctuations caused by insufficient cable bending radius.

[0109] As Figure 4 shown, the application proposes a temperature-aware-power adaptive algorithm combined with a wave control board, which avoids frequent power switching caused by temperature oscillation through quadratic function derating. The thermal time constant is embedded in the real-time control loop to realize thermal failure warning and function degradation instead of hard shutdown, and to ensure the robustness of the system under extreme working conditions.

[0110] The main purpose of the temperature-aware-power adaptive algorithm in the application is to avoid the chip junction temperature exceeding the safety threshold, and to maintain the highest effective radiation power under temperature constraints. At the same time, the temperature difference between the stacked layers / inter-channel (ΔT < 10℃) is reduced, and the thermal stress is inhibited.

[0111] In the application, the innovation of integrating the main heat dissipation path in the upper cover plate 1 reduces the thermal resistance by 35% compared to the traditional bottom heat dissipation. In the application scheme, the upper cover plate 1 integrates the micro-channel liquid cooling manifold heat dissipation structure 12, directly etches the micro-channel on the back of the chip silicon substrate, reduces the fluid channel to microns, breaks through the size limit of traditional liquid cooling, and realizes ultra-compact integration. At the same time, the application adopts a tree-shaped manifold to realize precise on-demand distribution of flow, directly guides the cooling liquid to the place closest to the heat source (below the chip), realizes "point-to-point" efficient cooling, greatly shortens the heat conduction path, and increases the heat dissipation efficiency. At the same time, the manifold and the micro-channel radiator and even part of the electronic packaging structure are designed and manufactured integrally (such as embedded liquid cooling), reducing the interface thermal resistance and improving the system reliability.

[0112] The application adopts a hierarchical manifold network topology layout, as Figure 2 shown, the first manifold layer 121 is a lumped layer, one inlet to four branches, covering the full array, distributing 60% of the total flow. The second manifold layer 122 is a regional layer, 4 branches to 16 sub-areas, each sub-area covering 16 antenna channels. The third manifold layer 123 is a channel layer, the micro-channel is directly connected to the chip, and the density is doubled directly above the heat source. The temperature-driven dynamic manifold control is shown in Table 1.

[0113] Table 1 Dynamic manifold control

[0114]

[0115] The derating factor is defined as:

[0116]

[0117] In the formulae: : derating threshold temperature (typical value 80℃), β : material thermal decay coefficient.

[0118] The actual output power after the total system power consumption is derated is:

[0119]

[0120] Wherein .

[0121] MTF is the mean time to failure, and the adaptive power algorithm in the application can greatly improve this value.

[0122] ;

[0123] is the activation energy, is the Boltzmann constant, is the junction temperature.

[0124] After the phased array antenna in the scheme adopts the adaptive power algorithm, the overall power consumption is reduced, and the reliability is improved, and the specific comparison results are shown in Table 2.

[0125] Table 2 Comparison of whether to use temperature-aware-power adaptive algorithm for derating

[0126]

[0127] The application adopts hierarchical protection according to the dynamic combination of over-temperature range / rate, and the protection level decision is as shown in the formula 1. Figure 5

[0128] The application realizes high-density multi-channel AOP+ integration, highly integrates antenna units and active radio frequency front-end chips containing PA / LNA / phase shifter and other key functions in a single module (AOP+ antenna), and realizes extreme miniaturization and consistency between channels of 64-unit subarrays in the millimeter wave frequency band.

[0129] The application adopts a three-dimensional vertical stacking architecture of AOP+ module->radio frequency adapter plate->wave control plate->lower cover plate. The built-in radio frequency adapter plate replaces a large number of discrete radio frequency cables through precise transmission lines, revolutionarily simplifies the internal interconnection of high-density millimeter wave subarrays, and significantly improves radio frequency performance (low insertion loss, high consistency), reliability and manufacturability.

[0130] ​The application adopts a shell integrated high-efficiency heat dissipation technology, innovatively uses the upper cover plate as a main radiator, and is directly and closely in thermal contact with a heat source of an AOP+ module, so that an ultra-short and low-thermal-resistance core heat dissipation path is constructed. The key problem of heat concentration of a high-integration millimeter wave AOP is solved, and system thermal reliability is ensured. In the application scheme, a micro-channel liquid cooling manifold is integrated on the outer surface of the upper cover plate, so that the heat conduction path is greatly shortened, and the heat dissipation efficiency is increased.

[0131] The application forms a standard and independently producible and testable module by using the whole subarray (64 units+AOP+radio frequency switching+wave control+shell). Meanwhile, the high and low frequency connectors are physically separated from the lower cover plate, so that the design is clear, system-level integration is facilitated, and signal crosstalk is effectively reduced.

[0132] Through the cooperation of physical layer innovation (stacking+heat dissipation) and system layer innovation (modularization+intelligent control), the application pushes the millimeter wave phased array from 'function realization' to 'engineering usability', solves the contradiction of three highs (high frequency, high density and high reliability), and provides bottom technology support for future scenarios such as 6G terahertz communication and low-orbit satellite phased array constellation.

[0133] The application proposes a temperature sensing-power adaptive algorithm combined with a wave control plate, embeds a thermal time constant into a real-time control loop, realizes thermal failure early warning and function degradation instead of hard shutdown, and guarantees the robustness of the system under extreme working conditions.

[0134] The application takes the cooling liquid flow and the environment temperature into real-time thermal resistance calculation, allocates a lower power weight to the channel of the stacking bottom layer (near the heat source), actively balances the temperature difference between the layers, and re-calculates the beam synthesis weight when the channel is closed, so that the EIRP loss is reduced to the theoretical limit.

[0135] Through four steps of manifold heat distribution sensing, mode dynamic adjustment, derating factor calculation and cooling cooperation, the application realizes power consumption reduction: more than 40%, junction temperature control ΔT> 20℃, and reliability improvement through MTF multiplication.

[0136] The three modes of the manifold described in Table 1, i.e. the uniform flow mode, the hot spot enhancement mode and the emergency bypass, belong to the hardware execution layer, and mainly aim at the physical regulation and control of the cooling system. Figure 4 The three modes in the power adaptive algorithm, i.e. the full power mode, the proportional power reduction mode and the hierarchical protection, belong to the decision layer, and are power adjustment strategies based on temperature states. They have a 'decision-execution' relationship. When the algorithm is in the full power mode, the manifold only needs to run the uniform flow mode to maintain basic cooling. When the algorithm switches to the proportional power reduction mode, the manifold needs to cooperate to enter the hot spot enhancement mode for accurate heat dissipation. When the algorithm triggers the hierarchical protection, the manifold needs to start the ultimate protection mode of the emergency bypass.

[0137] Figure 4 The three working conditions under the medium protection mode correspond to different modes of the manifold. The closing of the high-temperature channel + liquid cooling pressurization corresponds to the emergency bypass mode. The reduction of the scanning angle + derating corresponds to the hot spot enhancement mode. The full-array power reduction + air cooling corresponds to the uniform flow mode.

[0138] The control target values (such as the pressurization ratio, the scanning angle reduction range) of the liquid cooling pressurization, the reduction of the scanning angle, and the like are not fixed in advance, but are dynamically calculated based on the real-time temperature field, the thermal time constant, the system constraints, and the like, and are precisely controlled through closed-loop feedback. The effects are shown in Table 3.

[0139] Table 3: Thermal time constant decision table

[0140]

[0141] The above describes only the preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art, within the technical scope disclosed by the present application, according to the technical solution and inventive concept of the present application, makes equivalent replacements or changes, should be covered within the protection scope of the present application.

Claims

1. A millimeter wave phased array antenna subarray, characterized by: The application relates to a millimeter wave phased array antenna (AOP) cooling structure, which comprises, from top to bottom, an upper cover plate (1), an AOP antenna (2), a shell (3), a wave control plate (4) and a lower cover plate (5), wherein the AOP antenna (2) comprises N AOP antenna subarrays, and N is greater than or equal to 2. The upper cover plate (1) comprises an upper cover plate body (11) and a heat dissipation structure (12) connected inside the upper cover plate body (11). The heat dissipation structure comprises, from top to bottom, a first manifold layer (121), a second manifold layer (122) and a third manifold layer (123) connected inside the upper cover plate body (11) in sequence. The manifold diameters of the first manifold layer (121), the second manifold layer (122) and the third manifold layer (123) decrease in sequence, the manifold direction of the first manifold layer (121) is different from the manifold direction of the second manifold layer (122), the manifold of the third manifold layer (123) is a micron-diameter manifold obtained by directly etching a microchannel on a chip silicon substrate back, and the micron-diameter manifold is connected above the chip of the AOP antenna subarray. The first manifold layer (121) is a lumped layer, covers the whole array of the AOP antenna subarray, comprises one input port, K branches and K output ports, and the flow of each branch can be individually controlled. The second manifold layer (122) is a regional layer, comprises K branches connected with the K output ports of the first manifold layer (121) respectively, and each branch comprises L manifold channels. The third manifold layer (123) is a channel layer, comprises 4N microchannels, every N / 4 microchannels form a group and are connected with one manifold channel, and N / 4 is the product of L and K.

2. The millimeter wave phased array antenna subarray of claim 1, wherein: The dynamic control method of the heat dissipation structure (12) is as follows: when the maximum junction temperature T_max of the millimeter wave phased array antenna subarray is less than T_safe, the first manifold layer (121), the second manifold layer (122) and the third manifold layer (123) are in a uniform flow mode, T_safe is a safety temperature threshold value; when T_safe is less than or equal to T_max and T_max is less than or equal to T_th, the first manifold layer (121), the second manifold layer (122) and the third manifold layer (123) are in a hot spot enhancement mode, the manifold at the position of the overheated AOP antenna subarray increases by 20% flow, and T_th is a reduced threshold temperature; when T_max is greater than T_th, the first manifold layer (121), the second manifold layer (122) and the third manifold layer (123) are in an emergency bypass mode, the manifold above the AOP antenna subarray with a junction temperature less than T_th is closed, and concentrated liquid supply is conducted to the region where T_max is located.

3. The millimeter wave phased array antenna subarray of claim 1, wherein: The manifold direction of the first manifold layer (121) is perpendicular to the manifold direction of the second manifold layer (122), and the density of the microchannels above the chip of the AOP antenna subarray is doubled; K and L are both 4, N is 64, 60% of the total flow is distributed to the first manifold layer (121), and 40% of the total flow is used for system pressure balance, edge area cooling and bypass.

4. The millimeter wave phased array antenna subarray of claim 1, wherein: The first manifold layer (121) controls the flow by a frequency conversion pump, the second manifold layer (122) controls the flow by a proportional regulating valve, and the third manifold layer (123) controls the flow by the layout of micro-channels.

5. The millimeter wave phased array antenna subarray of claim 1, wherein: The radio frequency signal lines of the AOP antenna (2) are embedded in different layers of the adapter plate, and the radio frequency signals RF1 and RF2 are distributed in a strip line structure between two layers, and the vertical interconnection between the layers is realized by a coaxial structure. The AOP antenna (2) and the wave control plate (4) are connected by a radio frequency connector and a radio frequency adapter plate for signal transmission.

6. The millimeter wave phased array antenna subarray of claim 2, wherein: The adaptive heat dissipation method comprises the following steps: S1, collecting the junction temperature data of the millimeter wave phased array antenna subarray in real time, and constructing a temperature distribution map; When T_max < T_safe, step S2 is entered; When T_safe ≤ T_max ≤ T_th, step S3 is entered; When T_max > T_th, step S4 is entered; S2, the millimeter wave phased array antenna subarray is in full power mode, and the first manifold layer (121), the second manifold layer (122) and the third manifold layer (123) are in uniform flow mode, and step S5 is entered; S3, the millimeter wave phased array antenna subarray is in a proportional power reduction mode, and the derating factor is , the first manifold layer (121), the second manifold layer (122), and the third manifold layer (123) are in a hot spot enhancement mode, and entering step S5. S4, the millimeter wave phased array antenna subarray is in a hierarchical protection mode, the protection level is selected according to the proportion of the over-temperature area and the temperature rise rate, the antenna power is adjusted, the first manifold layer (121), the second manifold layer (122) and the third manifold layer (123) are in an emergency bypass mode, and step S5 is entered; S5, the wave control plate (4) generates a wave control instruction, which is sent to the phase shifter and the amplifier driver, the temperature change is monitored, and step S1 is returned.

7. The millimeter wave phased array antenna subarray of claim 6, wherein: Step S4 comprises the following steps: S41, the millimeter wave phased array antenna subarray is in a hierarchical protection mode, and the first manifold layer (121), the second manifold layer (122) and the third manifold layer (123) are in an emergency bypass mode; If the proportion of the over-temperature area is less than 5%, a first protection mode is entered, the channel where T_max of the millimeter wave phased array antenna subarray is located is closed, the operating pressure of the heat dissipation structure (12) is increased, and step S5 is entered; If not, step S42 is entered; S42, judging whether the heating rate is less than 5%, if yes, entering secondary protection mode, reducing the scanning angle of the millimeter wave phased array antenna subarray according to the thermal time constant τ and reducing the output power according to the derating factor K, and returning to step S41. ; The power is reduced, and step S5 is entered; If not, step S43 is entered; S43, a third protection mode is entered, the full array power of the millimeter wave phased array antenna subarray is reduced to 30%, and the air cooling is started, and step S5 is entered.

8. The millimeter wave phased array antenna subarray of claim 7, wherein: In step S42, ， wherein, Cp is the heat capacity, in J / K, which is the product of the specific heat capacity of the material and the mass; k is the thermal conductivity, in W / K, which is the inverse of the area thermal resistance.

9. The millimeter wave phased array antenna subarray of claim 7, wherein: In steps S3 and S42, ； wherein β is the thermal decay coefficient of the material; In steps S3 and S4, the actual output power after the system total power consumption is reduced is: ； wherein .

10. The millimeter wave phased array antenna subarray of claim 6, wherein: The adaptive heat dissipation method judges the heat dissipation effect by MTF: ； wherein, is the activation energy, is the Boltzmann constant, is the junction temperature, is the junction temperature without using the adaptive heat dissipation method, is the junction temperature after using the adaptive heat dissipation method, MTF is the mean time to failure, is the mean time to failure without using the adaptive heat dissipation method, is the mean time to failure after using the adaptive heat dissipation method.

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