Millimeter wave radar altimeter structure, manufacturing process and control system

Abstract

A millimeter wave radar altimeter structure disclosed by the present invention comprises a shell, the shell is provided with a plurality of functional areas and integrates a plurality of functional units, the functional units comprise a radio frequency unit, an intermediate frequency processing unit and a signal control unit, and the plurality of functional units are compactly arranged in the shell. The radio frequency unit comprises at least one high-power emission chip, the chip is installed on a heat conduction substrate, and the substrate is in contact with the shell to form a heat conduction path. The shell is made of a high-heat-conductivity material, and a plurality of heat dissipation structures are arranged outside the shell, so that the heat dissipation efficiency under natural convection is improved. The heat conduction substrate, the shell material and the heat dissipation structure form a continuous heat dissipation path from the chip to the environment, heat accumulation is effectively restrained, and stable work of the chip is guaranteed. The shell further comprises a sealing structure, a sealed space is formed by a sealing groove, a sealing element, the antenna cover and the packaging cover plate, and environment sealing protection is achieved. The signal control unit is connected with peripheral equipment through an external interface, and the interface supports power supply and data communication of the altimeter.

Description

Technical Field

[0001] The present invention relates to the technical field of millimeter-wave radar ranging, and in particular to a millimeter-wave radar altimeter structure, manufacturing process and control system. Background Art

[0002] In recent years, unmanned aerial vehicles (UAVs) have played an increasingly important role in multiple scenarios such as industrial inspection, farmland monitoring, logistics transportation, emergency rescue and military reconnaissance, and the degree of flight intelligence and autonomy has been continuously improved. Among them, the flight altitude information, as one of the core parameters of the control system, its measurement accuracy and real-time performance are directly related to flight safety and navigation accuracy. To ensure the stable operation of UAVs under complex terrains and changing climate conditions, there is an urgent need for a height measurement solution with stable performance, strong anti-interference ability and excellent environmental adaptability. Due to its good penetration and high measurement accuracy, millimeter-wave radar has gradually shown technical advantages in the field of altitude detection and has become a key direction to replace traditional ranging methods.

[0003] Currently, most mainstream UAVs use ultrasonic, laser, vision and other methods for altitude measurement. These technologies have certain advantages in terms of simple structure and fast response, but generally have limitations such as weak anti-interference ability, short operating distance and environmental sensitivity, and it is difficult to meet the requirements of complex application scenarios. For this reason, millimeter-wave radar altimeters have begun to enter the market and have alleviated the shortcomings of traditional ranging solutions to a certain extent. However, there are still obvious deficiencies in the engineering implementation of existing millimeter-wave radar altimeters: their core functional modules such as the radio frequency front end, intermediate frequency circuit and signal processing circuit mostly adopt a split structure and are distributed in multiple cavities, resulting in a scattered device structure, cumbersome assembly and large volume, and it is difficult to achieve high integration and miniaturization. At the same time, the thermal conductivity of the cavity material is limited, and it is difficult to effectively dissipate the heat generated by high-power chips. Coupled with insufficient sealing and protection design, it is difficult to operate stably for a long time in complex outdoor environments such as high temperature, high humidity and multi-dust.

[0004] Therefore, there is an urgent need for a millimeter-wave radar altimeter structure with high structural integration, excellent thermal management performance and reliable sealing design to solve the problem that existing millimeter-wave radar altimeters are difficult to operate stably for a long time in complex outdoor environments such as high temperature, high humidity and multi-dust, so as to improve its practicability and reliability on flight platforms such as UAVs. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art. For this reason, an object of the present invention is to propose a millimeter-wave radar altimeter structure, and the millimeter-wave radar altimeter includes: A housing, the housing is provided with a plurality of functional areas for integrating a plurality of functional units, the plurality of functional units at least include a radio frequency unit, an intermediate frequency processing unit and a signal control unit, and the plurality of functional units are integrated in the housing in a compact layout manner, aiming to reduce the overall size of the machine and improve the system modularization level; The radio frequency unit includes at least one high-power transmitting chip, the high-power transmitting chip is mounted on a heat conduction substrate, and the heat conduction substrate is in contact with the housing by welding or other thermal connection means to construct a heat conduction path, so as to effectively transfer the heat generated during the operation of the chip to the housing; The housing is a structural member made of a material with excellent thermal conductivity, and a plurality of heat dissipation structures are arranged on its external part to enhance the heat dissipation efficiency under natural convection conditions; The heat conduction substrate, the housing material and the heat dissipation structure together constitute a continuous heat conduction path from the chip to the environment, thereby reducing the risk of heat accumulation under high-integration layout and ensuring the stable operation of the high-power chip; The housing further includes a sealing structure, the sealing structure includes a sealing groove and a sealing element, and cooperates with the radome and the packaging cover plate to form a closed space for providing environmental protection and sealing for the functional unit; The signal control unit is connected to a peripheral device through an external interface, and this interface supports the power supply and data communication of the altimeter.

[0006] In some examples of the present invention, the high-power transmitting chip is mounted on a copper carrier plate made of molybdenum-copper composite material, and the copper carrier plate is fixed in the housing by AuSn eutectic soldering and is used to conduct the heat of the chip to the housing.

[0007] In some examples of the present invention, the radio frequency unit is arranged in the front-side functional area of the housing, and includes at least one group of microstrip array transmitting antennas and at least one group of microstrip array receiving antennas, which are respectively connected to the transmitting chip and the receiving chip by wire bonding; the transmitting chip and the receiving chip are connected to a power supply circuit arranged inside the housing through a power divider circuit, and the power divider circuit is used to distribute the power signal to each chip, and the power supply circuit provides the working voltage required by the radio frequency unit.

[0008] In some examples of the present invention, a radome is arranged above the radio frequency unit, the radome is fixed to the corresponding area of the housing by screws, the housing is provided with a sealing groove and an O-ring, and the radome forms a sealed antenna chamber with the housing after pressing the O-ring.

[0009] In some examples of the present invention, a heat dissipation cover plate is mounted on the back of the housing. The heat dissipation cover plate is in contact with the copper carrier plate through a thermal conductive gasket and is fixedly connected to the housing by screws, so as to achieve multi-stage heat conduction of the chip heat to the environment.

[0010] In some examples of the present invention, partition bars and partition plates are arranged inside the housing. The partition bars are arranged between the intermediate frequency processing circuit and the signal and control processing circuit for electromagnetic isolation; one side of the partition plate supports the intermediate frequency processing module, and the other side supports the signal processing module, constituting a structure reuse assembly.

[0011] In some examples of the present invention, the intermediate frequency processing circuit board and the signal and control processing circuit board are fixed to the housing or the partition plate through preset mounting holes and a plurality of metal screws, and the screws are also used to fix the copper carrier plate, the radome and the heat dissipation cover plate.

[0012] In some examples of the present invention, a J30JM connector is provided on the side of the housing. The connector is connected to the interface pad on the signal and control processing circuit board by welding, so as to realize the power supply and serial port communication connection to an external system.

[0013] In some examples of the present invention, the radome, the heat dissipation cover plate and the housing are mechanically assembled through a plurality of screws. The screws sequentially pass through the structural parts and the mounting holes and are locked to form a reliable assembly structure and ensure the encapsulation sealing performance.

[0014] Another object of the present invention is to propose a manufacturing method of a millimeter wave radar altimeter structure, including the following steps: Material pretreatment: Prepare a gold-tin solder sheet, and use a plasma cleaning device to perform surface treatment on components such as the cavity, the heat dissipation cover plate, and the gold-tin solder sheet to remove oil stains and oxides; Eutectic welding of the chip: The high-power transmitting chip is eutectically welded through a gold-tin alloy solder and fixed on the molybdenum-copper carrier plate to form a high heat conduction structure unit; Sintering and assembly of the microstrip circuit board: Protect the front sides of the radio frequency circuit, the microstrip array transmitting antenna, and the microstrip array receiving antenna circuit board by attaching high-temperature tape. After cleaning the groove of the cavity, evenly apply tin-silver-copper solder in the groove, fit the circuit board into the corresponding groove, sinter it through a heating platform. After sintering is completed, remove the tape and remove the overflow solder under a microscope; Install the eutectic chip module: Apply lead-tin solder to the eutectic chip installation area in the cavity, place the carrier plate module completed in step 2 at this position, and achieve firm welding through heat treatment; Chip connection: Establish an electrical connection between the high-power transmitting chip and the radio frequency circuit by using the gold wire bonding method to form a millimeter wave signal channel; IF and signal module assembly: On the other side of the cavity, fix the IF processing circuit board to the housing through the combination screws, and fix the spacer to the IF processing circuit board through the countersunk screws; then fix the partition board inside the housing through screws as the installation support for the signal and control processing circuit board, and fix it to the partition board through the combination screws; Communication interface welding: Install the J30JM connector on the side wall of the cavity, and weld the connector cable to the corresponding pads of the signal and control processing circuit board through solder wire to achieve power supply and data communication connections; Final encapsulation: Install the radome and the sealing ring on the RF unit side of the cavity, and install the heat dissipation cover plate and the sealing ring on the signal processing module side. The radome and the heat dissipation cover plate are respectively fastened to the cavity through screws, and the sealing ring is pressed and arranged in the corresponding sealing groove of the cavity, so as to form a complete closed sealing structure in the front and back directions to complete the overall assembly of the millimeter-wave radar altimeter.

[0015] Another object of the present invention is to propose a control system for a millimeter-wave radar altimeter. The signal control unit includes an altimeter control motherboard installed inside the housing. The motherboard integrates a radio frequency control module, a signal acquisition module, a signal processing module, and a general interface module; the radio frequency control module is electrically connected to the radio frequency unit and is used to control the transmission and echo reception of W-band frequency-modulated continuous wave signals; the signal acquisition module is used to convert the received analog echo signal into a digital signal; the signal processing module includes an FPGA module, and the FPGA module is used to perform frequency domain conversion, filtering processing, and height estimation on the digital signal, and output the predicted height information to an external device or an indication module through the general interface module.

[0016] In some examples of the present invention, a fast Fourier transform (FFT) module, a moving target detection (MTD) module, a constant false alarm rate detection (CFAR) module, and an α-β filtering module are integrated in the FPGA module; the FFT module is used to convert the digital signal from the time domain to the frequency domain signal, the MTD module is used to suppress static clutter signals, the CFAR module is used to identify effective target echo signals, and the α-β filtering module is used to smooth the target signal and output the estimated height.

[0017] In some examples of the present invention, the altimeter control motherboard is composed of a stacked first motherboard, second motherboard, and third motherboard, which are respectively used to carry the radio frequency control module, signal acquisition module, and signal processing module; a metal electromagnetic isolation board is arranged between the motherboards, and the whole is installed in the functional area where the signal control unit is located in the housing, so as to achieve electromagnetic shielding between modules and optimize the wiring structure.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description, will become apparent in part from the following description, or will be understood through the practice of the present invention. It has the following beneficial effects: The millimeter-wave radar altimeter structure provided by the present invention integrates a radio frequency unit, an intermediate frequency processing unit, and a signal control unit in a compact manner within a unified housing, effectively overcoming problems such as discrete function distribution, complex wiring, and incompatible interfaces between modules in existing products. Through structural integration and functional integration, the overall volume of the machine is significantly reduced, and the internal connection relationship is clear, which is suitable for flight platforms with high requirements for structural dimensions, assembly efficiency, and system reliability.

[0019] The high-power transmitting chip set in the radio frequency unit is installed through a heat conduction substrate and forms a stable thermal connection relationship with the housing. The housing is made of a high thermal conductivity material, and a heat dissipation structure is arranged outside, forming a complete thermal conduction path from the chip to the external environment. This thermal management structure can significantly reduce the thermal resistance, improve the thermal diffusion efficiency, meet the stable operation requirements of high-power transmitting devices under high duty cycle conditions, and suppress performance drift or device failure caused by heat accumulation.

[0020] The introduction of the high-power transmitting chip not only improves the transmitting power level and signal integrity of the system, but also enhances the directivity and penetration ability of the millimeter-wave beam. Combined with the integrated optimization of the system structure, this solution can significantly improve the measurement resolution and effective operating distance of the radar altimeter on the premise of ensuring system stability, meet the requirements for accuracy and coverage ability in complex scenarios, and solve the problem of "insufficient ranging ability" of traditional low-power radar systems.

[0021] The sealing grooves and sealing elements arranged in the housing, together with the radome and the packaging cover plate, jointly form a closed structure, which effectively hermetically packages the radio frequency, power supply, and control modules. This structure can maintain the stable operation of key components in typical harsh environments such as high humidity, high temperature, and multi-dust, meet the engineering application requirements such as field deployment and long-term operation, and improve the environmental adaptability and reliability level of the system.

[0022] The signal control unit realizes the power supply and communication functions through the interfaces arranged on the housing. The interface structure is clear and the form is standard, which can be directly docked with existing flight control systems and measurement and control platforms, and has good system compatibility and engineering application expandability.

[0023] In summary, based on the structural integration design, the construction of the high-power chip thermal management path, and the sealing structure protection scheme, the present invention systematically improves the comprehensive technical level of the millimeter-wave radar altimeter in terms of structural compactness, thermal stability, ranging performance, and environmental adaptability, and has clear technological progressiveness and engineering practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 Schematic diagram of the external structure of the millimeter-wave radar altimeter provided by an embodiment of the present invention; Figure 2 Schematic diagram of the assembly structure of the millimeter-wave radar altimeter provided by an embodiment of the present invention; Figure 3 Schematic diagram of the internal structure of the millimeter-wave radar altimeter provided by an embodiment of the present invention; Figure 4 Heat dissipation diagram in the heat dissipation structure; Figure 5 Heat propagation path diagram of the heat dissipation structure; Figure 6 Installation flowchart of the millimeter-wave radar altimeter provided by an embodiment of the present invention.

[0026] Description of the reference numerals: 1. Housing; 2. RF unit; 3. Intermediate frequency processing unit; 4. Signal control unit; 5. High-power transmitting chip; 6. Thermal conduction substrate; 7. Heat dissipation structure; 8. Radome; 9. Encapsulation cover plate; 10. Sealing groove; 11. Sealing element; 12. External interface; 13. Transmitting antenna; 14. Receiving antenna; 15. Power splitting circuit; 16. Power supply circuit; 17. Spacer; 18. Partition board; 19. Thermal conductive gasket; 20. Heat dissipation cover plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] In order to make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, features defined as "first", "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more. In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0029] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0030] Figure 1 Schematic diagram of the external structure of the millimeter-wave radar altimeter provided by the embodiment of the present invention; Figure 2 Schematic diagram of the assembly structure of the millimeter-wave radar altimeter provided by the embodiment of the present invention; Figure 3 Schematic diagram of the internal structure of the millimeter-wave radar altimeter provided by the embodiment of the present invention; Figure 4 Heat dissipation diagram in the heat dissipation structure; Figure 5 Heat propagation path diagram of the heat dissipation structure; Figure 6 Installation flow chart of the millimeter-wave radar altimeter provided by the embodiment of the present invention.

[0031] The following references Figures 1-4Describe a millimeter-wave radar altimeter structure provided according to an embodiment of the present invention, including a housing 1. The housing 1 is provided with multiple functional areas for integrating multiple functional units. The multiple functional units at least include one radio frequency unit 2, one intermediate frequency processing unit 3, and one signal control unit 4. The multiple functional units are integrated in the housing 1 in a compact layout manner, aiming to reduce the overall size of the machine and improve the system modularization level. The radio frequency unit 2 includes at least one high-power transmitting chip 5. The high-power transmitting chip 5 is installed on a heat conduction substrate 6. The heat conduction substrate 6 is in contact with the housing 1 through welding or other thermal connection methods to construct a heat conduction path, so as to effectively transfer the heat generated during the operation of the chip to the housing 1. The housing 1 is a structural member made of a material with excellent thermal conductivity. Multiple heat dissipation structures 7 are arranged on its exterior for enhancing the heat dissipation efficiency under natural convection conditions. The heat conduction substrate 6, the housing 1 material, and the heat dissipation structures 7 together constitute a continuous heat conduction path from the chip to the environment, thereby reducing the risk of heat accumulation under high-integration layout and ensuring the stable operation of high-power chips. The housing 1 further includes a sealing structure. The sealing structure includes a sealing groove 10 and a sealing element 11, and cooperates with the radome 8 and the packaging cover plate 9 to form a closed space for providing environmental protection and sealing for the functional units. The signal control unit 4 is connected to peripheral devices through an external interface 12, and this interface supports the power supply and data communication of the altimeter.

[0032] The millimeter-wave radar altimeter of this embodiment realizes the layout optimization of compact structure and coordinated functions by integrating multiple functional modules in the integrated housing 1. The high-power transmitting chip 5 built in the transmitting unit is fixed on the molybdenum-copper composite substrate by AuSn eutectic soldering. The heat conduction substrate 6 is then in close contact with the housing 1 through welding or thermal bonding to construct a complete heat diffusion path from the chip to the environment. The housing 1 is made of aluminum alloy 6063, which has excellent thermal conductivity, and multiple heat dissipation tooth structures are designed around it for enhancing the heat dissipation efficiency under natural convection conditions. The signal is emitted from the transmitting antenna 13, reflected by the ground, received by the receiving antenna 14, transmitted to the intermediate frequency processing module, and further analyzed and communicated by the signal control unit 4. The housing 1 is provided with a sealing groove 10 and an O-ring. The front and back sides are respectively pressed and sealed by the radome 8 and the heat dissipation cover plate 20 to ensure the safe operation of the circuit module in environments such as dusty and high humidity. The signal control unit 4 completes power supply and data interaction through the J30JM interface provided on the side wall of the housing 1 to form a complete closed-loop system.

[0033] The millimeter-wave radar altimeter structure achieves technological breakthroughs and system optimizations in multiple dimensions. By integrating multiple functional modules into a single housing 1 through structural integration, problems such as large volume, complex assembly, and unstable wiring in the traditional multi-housing 1 structure are solved, realizing miniaturization and modularization of the whole machine. In the thermal management design, through the continuous heat conduction path composed of a high thermal conductivity substrate - housing 1 - heat dissipation structure 7, the working temperature rise of the chip is effectively reduced to adapt to high-power long-time working loads. The use of high-power transmitting chips improves the penetration, directivity, and stability of millimeter-wave signals, enhances ranging performance, and expands the effective operating distance, especially suitable for low-altitude complex scenarios. The sealing structure enhances the environmental adaptability of the system, enabling it to have a protection level above IP65 and being suitable for various harsh working conditions such as outdoor, shipborne, high humidity, and high temperature. The standard interface design improves the system compatibility and expandability, and can be seamlessly docked with existing flight control systems and industrial control platforms. The assembly structure is modular and the operation process is clear, suitable for batch production and engineering deployment, significantly improving the manufacturing efficiency and maintenance convenience. In summary, the present invention comprehensively improves the technical level of the millimeter-wave radar altimeter system from aspects such as structural optimization, thermal stability, radio frequency performance, and engineering applicability, and has significant technological progressiveness and practical value.

[0034] In the above embodiments, the heat conduction substrate 6 can be replaced with a heat-conducting ceramic, a silver-copper composite material, or a graphene-based material to meet different thermal design requirements; the material of the housing 1 can be selected from lightweight and high-thermal-conductivity materials such as copper alloy and magnesium alloy to balance cost, weight, and strength; the heat dissipation structure 7 can be adjusted to a dense fin type, an open-hole structure, or a forced convection design; in addition to the O-ring, the sealing method can also use forms such as a foamed silicone strip and a hot-pressed sealant; the external interface 12 can be selected as an Ethernet interface, a CAN communication interface, or an aviation plug according to the system requirements; in terms of the connection method, the thermal connection can be replaced from welding to forms such as screw pressing and silver glue bonding to adapt to different manufacturing and maintenance scenarios; in addition, the module position can also be fine-tuned structurally according to the platform installation constraints to optimize the space utilization rate while maintaining the system performance.

[0035] Please continue to participate Figures 1-3 As shown, in a possible embodiment, the high-power transmitting chip 5 is installed on a copper carrier plate made of molybdenum-copper composite material. The copper carrier plate is fixed in the housing 1 by the eutectic soldering method of gold-tin alloy and is used to conduct the heat of the chip to the housing 1.

[0036] In this embodiment, a copper carrier plate made of Mo80Cu20 molybdenum-copper composite material is used as the mounting substrate for the high-power emission chip 5, effectively improving the heat dissipation efficiency of the device. The molybdenum-copper composite material has good thermal conductivity and a small coefficient of thermal expansion. Its thermal conductivity is above 150 W / (m·K), and it also has excellent structural stability and thermal matching characteristics, suitable for long-term eutectic thermal connection with chip materials (such as gallium arsenide). During the specific implementation process, the Au80Sn20 gold-tin solder is first cut to the same size as the bottom surface of the chip and laid on the surface of the carrier plate. After plasma cleaning, it is paired with the chip and placed. Then, it is preheated to about 240 °C on the eutectic platform and heated to 300 - 310 °C to perform eutectic soldering, forming a firm high-heat conduction interface between the chip and the copper carrier plate. After eutectic, the carrier plate module is fixed by secondary soldering in the set welding area in the cavity to ensure that the bottom surface of the carrier plate is in close contact with the structure of the housing 1, constructing an efficient heat conduction channel from the chip to the carrier plate to the housing 1.

[0037] This embodiment significantly improves the heat diffusion ability of the high-power chip in the high-duty-cycle working state. Through structural integrated soldering, a thermal connection with low thermal resistance, low stress, and high strength is achieved, effectively suppressing the temperature fluctuation of the chip during continuous high-power output, avoiding thermal drift and failure, and improving the system reliability and continuous working ability. Compared with traditional aluminum-based or ceramic substrates, the thermal properties of the molybdenum-copper composite material are more matched with the chip packaging material, which can reduce the interface stress and improve the long-term soldering stability. In addition, the eutectic soldering method is used instead of ordinary brazing or thermal conductive adhesive connection method, which improves the thermal coupling efficiency and enhances the mechanical strength of the carrier plate, meeting the requirements of structural integrity in high-vibration and high-thermal-cycle environments.

[0038] In the above embodiment, the copper carrier plate can also be made of materials such as MoCu30, WCu (tungsten-copper alloy), and AlN composite ceramics to adjust the combination of thermal conductivity and coefficient of thermal expansion and adapt to different chip packaging processes; the eutectic soldering method can be replaced by vacuum brazing, hot-press sintering, silver sintering, etc. to improve the joint reliability or adapt to low-oxygen conditions; the connection method between the carrier plate and the housing 1 can also be screw pressing or silver glue bonding to meet the requirements of module disassembly or rapid assembly; at different sizes and power consumption levels, the thickness, area, and surface treatment process (such as nickel plating and gold plating) of the copper carrier plate can also be optimized to adapt to different heat flux densities and the contact structure of the housing 1.

[0039] Please continue to refer to Figures 1-3As shown, according to an embodiment of the present invention, the radio frequency unit 2 is disposed in the front functional area of the housing 1 and includes at least one set of microstrip array transmitting antennas 13 and at least one set of microstrip array receiving antennas 14, which are respectively connected to the transmitting chip and the receiving chip by wire bonding; the transmitting chip and the receiving chip are connected to the power supply circuit 16 disposed inside the housing 1 through a power splitter circuit 15, and the power splitter circuit 15 is used to distribute the power signal to each chip, and the power supply circuit 16 provides the working voltage required by the radio frequency unit 2.

[0040] In this embodiment, the radio frequency unit 2 is centrally disposed in the front area of the housing 1 to form a key front-end sub-module for signal transmission and reception. Two sets of microstrip array transmitting antennas 13 and two sets of microstrip array receiving antennas 14 are integrated in this radio frequency area. The corresponding transmitting chips and receiving chips are respectively mounted on preset metal carrier plates, and high-frequency signal channels are formed with the antenna circuits through wire bonding technology. The wire bonding method can ensure the signal connection stability and low insertion loss characteristics in the millimeter wave band, and at the same time has good processing compatibility and batch process stability. The connection relationship between the above chips is constructed by the power splitter circuit 15 disposed inside the housing 1. The power splitter circuit 15 is designed based on a microstrip structure or a hybrid integrated form. Its input end is connected to the output of the power supply circuit 16, and the output end is equally divided into multiple branches to feed each transmitting or receiving chip respectively, so as to realize the power distribution and matching adjustment of the local oscillator signal or the power signal.

[0041] The power supply circuit 16 is arranged in the exclusive power area inside the housing 1 and constitutes a stable DC power supply system through a low-noise voltage regulator, a filter network and a protection unit. It provides a stable and isolated working voltage for multiple functional chips of the radio frequency front end, suppresses the noise coupling from the power supply system, and improves the signal-to-noise ratio of the receiving signal chain. The whole structure makes full use of the internal space of the housing 1, optimizes the radio frequency path length and the ground plane layout by regional function division, reduces the high-frequency loss and improves the electromagnetic compatibility of the system.

[0042] Through designs such as clear module distribution, optimized connection path, and rationalized power management, this embodiment constructs a radio frequency front-end system with high gain, high linearity and high consistency, effectively improving the detection resolution and echo recognition ability of the millimeter wave altimeter in complex reflection and multipath interference scenarios. Through wire bonding and integrated power splitter power supply circuit 16, the structural compactness and electronic connection reliability are greatly improved, and the performance attenuation or failure risk caused by thermal deformation and joint loosening in traditional welding connections is reduced. The overall structure is suitable for application scenarios with high requirements for response speed and signal accuracy, such as micro unmanned aerial vehicles and high-speed target detection.

[0043] It should be noted that the form of the microstrip array antenna can be replaced by a dielectric patch array, an SIW waveguide array or a silicon-based CMOS on-chip antenna, which is suitable for different packaging and frequency band requirements; the wire bonding connection method can be replaced by flip-chip bonding, TAB bonding or crimp welding according to the packaging process to adapt to the chip process differences; the structure of the power divider circuit 15 can also be adjusted based on impedance transformation type, mixing type or multi-stage filtering type topology to obtain better voltage standing wave ratio and phase consistency; the power supply circuit 16 can integrate a high-voltage isolation module or a redundant switching module to improve electromagnetic compatibility and reliability in a multi-power supply system.

[0044] Please continue to refer to Figure 1 As shown, in a possible implementation, an antenna cover 8 is provided above the radio frequency unit 2. The antenna cover 8 is fixed to the corresponding area of the housing 1 by screws. The housing 1 is provided with a sealing groove and an O-ring. After the antenna cover 8 presses the sealing ring, a sealed antenna chamber is formed with the housing 1.

[0045] In this implementation, the radio frequency unit 2 is externally covered with an antenna cover 8. The antenna cover 8 is made of radio frequency transparent materials, such as polytetrafluoroethylene, polysulfone or polycarbonate, etc. It has excellent electromagnetic wave transmission performance and environmental adaptability, can effectively protect the microstrip antenna array from external mechanical impacts, water vapor, dust and other factors, and at the same time ensure that the millimeter wave signal is transmitted without attenuation. The edge of the structure of the antenna cover 8 is designed with screw fixing holes, and is mechanically fastened to the screw holes of the housing 1 through metal screws to ensure that the cover body is firmly installed in the corresponding antenna area at the front of the housing 1 and maintains a stable relative position relationship.

[0046] An annular sealing groove is machined in the front structure of the housing 1 for embedding an O-ring silicone rubber sealing ring. The cross-sectional dimension of the sealing ring is slightly larger than the groove depth, so that it is compressed by force during installation to fill the gap and form an airtight seal. A sealed contact surface is formed between the bottom surface of the antenna cover 8 and the outer surface of the housing 1 through the sealing ring. When the screw is tightened, the antenna cover 8 evenly compresses the sealing ring into the groove, thereby forming a closed antenna chamber. This chamber plays a comprehensive packaging and protection role for the microstrip array, wire bonding wires and exposed chips of the radio frequency front end.

[0047] This sealing structure not only has excellent waterproof, dustproof and corrosion-proof capabilities, but also is superior to traditional potting structures in terms of structural strength, durability and repeated disassembly and assembly performance, meeting the requirements of long-term field deployment and high-frequency disassembly and maintenance. The closed antenna chamber is kept dry, clean and free from stray electric field interference, which is beneficial to maintaining the antenna matching accuracy and working consistency, and improving the stability of radar signal transmission and reception.

[0048] It should be noted that the material of the radome 8 can be a modified plastic or ceramic material with a low dielectric constant according to different frequency bands; the fixing method can also be replaced from mechanical screws to snap - lock structures, rotary positioning structures or quick - release plug - lock structures to improve the assembly efficiency; in addition to the O - ring seal, the sealing structure can also adopt methods such as two - component liquid silicone potting and thermo - formed gaskets to meet different protection levels and process conditions; the shape of the sealing groove can be optimized to a triangular, trapezoidal or double - layer structure to enhance the pressing force and aging resistance, and is suitable for application scenarios with higher reliability requirements.

[0049] Please continue to refer to Figure 4 and Figure 5 As shown, according to another embodiment of the present invention, a heat - dissipation cover plate 20 is installed on the back of the housing 1. The heat - dissipation cover plate 20 is in contact and fit with the copper carrier plate through a thermal - conductive gasket 19 and is fixedly connected to the housing 1 by screws, so as to realize the multi - stage heat conduction of the chip heat to the environment.

[0050] In this embodiment, a detachable heat - dissipation cover plate 20 is integrated on the back of the radar altimeter housing 1. Its main function is to provide an auxiliary heat - dissipation channel for the high - power transmitting chips 5 and high - power - consumption digital devices installed inside. The heat - dissipation cover plate 20 is made of a metal material that matches the material of the housing 1 or has a higher thermal conductivity, such as aluminum alloy 6063 or copper alloy, and its surface can be treated with anodic oxidation, thermal - conductive coating, etc. to enhance the heat - exchange efficiency and corrosion resistance. The inner surface of the heat - dissipation cover plate 20 is provided with a positioning surface corresponding to the copper carrier plate, and is supplemented with a soft thermal - conductive gasket 19. The thermal - conductive gasket 19 usually adopts a silicone - based high - thermal - conductivity sheet material, such as a compression - type material with a thermal conductivity of 3 - 8 W / (m·K). While ensuring the heat - contact transfer efficiency, it can also buffer the stress difference caused by thermal expansion.

[0051] During the assembly process, the thermal - conductive gasket 19 is first attached to the inner surface of the heat - dissipation cover plate 20 to form a tight fit with the top surface of the copper carrier plate; then the heat - dissipation cover plate 20 is locked and fixed to the back of the housing 1 by screws. The screw structure passes through the positioning holes and presses the entire assembly, realizing the multi - stage heat transfer path of the heat between the modules from the chip, the carrier plate, the thermal - conductive gasket 19, the heat - dissipation cover plate 20 to the air.

[0052] The thermal management achieved by this structure can greatly improve the local heat - dissipation capacity under natural - convection conditions, effectively reduce the core temperature of the chip, is particularly suitable for continuous high - power and high - load operating environments, and extends the service life of key electronic components. Compared with the structure that solely relies on the housing 1 for heat dissipation, this solution enhances the flexibility and expandability of the system thermal design while maintaining a high degree of integration, and at the same time maintains good detachability, facilitating maintenance and module replacement.

[0053] It should be noted that the thermal conductive gasket 19 can be selected from graphite film, phase change material or multi-layer composite thermal conductive medium according to different heat flux densities; the structure of the heat dissipation cover plate 20 can adopt fin-type strengthening design, honeycomb cavity-type lightweight structure, or integrated heat pipe module to improve the heat diffusion performance; in addition to screws, the fixing method can also adopt snap, slide rail, magnetic adsorption locking structure to improve the maintenance convenience and assembly efficiency; in occasions with higher sealing requirements, a sealing gasket or sealing rubber ring can be added to the edge of the cover plate to form a secondary protection with the housing 1 and improve the environmental adaptability level of the whole machine.

[0054] Please continue to refer to Figure 2 As shown, according to an optional embodiment of the present invention, partition bars 17 and a partition plate 18 are arranged inside the housing 1. The partition bar 17 is arranged between the intermediate frequency processing circuit and the signal and control processing circuit for electromagnetic isolation; one side of the partition plate 18 supports the intermediate frequency processing module, and the other side supports the signal processing module, constituting a structure reuse assembly.

[0055] In this embodiment, in order to improve the electromagnetic compatibility and module integration efficiency of the millimeter-wave radar altimeter, the design of partition bars 17 and a partition plate 18 is introduced into the internal space structure of the housing 1. The partition bar 17 is made of metal or conductive plastic material and is in the form of a strip-shaped component. It is installed between the intermediate frequency processing circuit board and the signal and control processing circuit board. Its height matches the installation surface of the circuit board, and it can form an effective shielding partition in the electromagnetic interference sensitive area. The partition bar 17 is fixed to the structural surface of the housing 1 by countersunk screws, with high installation accuracy, good stability, and lasting electromagnetic isolation effect. It can prevent the crosstalk or leakage of high-frequency signals or switching currents between the two circuit modules, and ensure the accuracy and stability of the radar ranging signal chain.

[0056] The partition plate 18 is a regular-shaped reusable structural component arranged in the back area of the housing 1. One side plane of it serves as the installation support surface of the intermediate frequency processing circuit board, and the other side serves as the assembly platform of the signal processing module, realizing the functional division and common support of the circuit modules in different spatial areas. The partition plate 18 is usually made of lightweight and high-strength metal materials such as aluminum alloy and is provided with general installation holes for cooperating with screws to lock the circuit board or other structural components to form a reliable installation relationship. The partition plate 18 realizes "one component with multiple uses" in terms of structure, not only simplifies the support structure design inside the housing 1, but also improves the space utilization rate.

[0057] This embodiment enables the millimeter-wave radar system to effectively partition the signal functional area and the control functional area within a limited structural space, which is beneficial to reducing the risk of mutual interference between modules and improving the stability and measurement accuracy of system operation. At the same time, the structure-reusable partition plate 18 combines the assembly of the two circuit units on one structure body, effectively reducing the number of parts, optimizing the assembly process, and improving the system integration degree, which is applicable to avionics and intelligent sensing systems with high requirements for assembly compactness and structural reliability.

[0058] It should be noted that the material of the spacer strip 17 can be selected as nickel-plated aluminum plate, conductive foam strip, etc. to improve the shielding performance or absorption ability; the shape of the partition 18 can be designed as an L-shaped, H-shaped or double-sided boss structure according to the cavity characteristics of the housing 1 to enhance the bearing strength and space compatibility; the connection method between the partition 18 and the circuit board can also adopt structural deformations such as slot insertion, slide rail introduction or magnetic fixation, etc., to further improve the modular assembly efficiency and maintainability.

[0059] Please continue to refer to Figure 1 and Figure 3 As shown, in an alternative embodiment of the present invention, the intermediate frequency processing circuit board and the signal and control processing circuit board are fixed to the housing 1 or the partition 18 through preset mounting holes and a plurality of metal screws. The screws are also used to fix the copper carrier plate, the radome 8 and the heat dissipation cover plate 20.

[0060] In this embodiment, the intermediate frequency processing circuit board and the signal and control processing circuit board serve as the intermediate frequency signal chain processing unit and the system control operation unit of the millimeter wave radar altimeter respectively, and are arranged on different sides of the partition 18 or on the designated platform inside the housing 1 according to the internal structure partition of the housing 1. Each circuit board is preset with standardized screw mounting hole positions according to the installation requirements. The layout positions of the mounting holes are precisely matched with the internal screw holes in the housing 1 and the through holes on the partition 18, so as to form a stable connection in the mechanical structure. During the installation process, the metal countersunk head screws pass through the mounting holes from the surface of the circuit board and are locked with the structure of the housing 1 or the partition 18, so that the circuit board is firmly installed, avoiding problems such as loosening and warping under vibration or dropping conditions.

[0061] The screws used for circuit board installation have multiple functions in structural design. Through systematic through hole arrangement and matching with fasteners of unified specifications, the screws of the same batch can be used simultaneously for fixing the pressing of the sealing ring of the radome 8, the assembly connection of the heat dissipation cover plate 20, and the thermal pressing fit of the copper carrier plate, forming a unified and streamlined fastening system. By sharing the fixed points of these structural components, not only the types and quantities of fastening elements are reduced, but also the assembly operation steps are simplified, improving the system integration efficiency and production consistency. This structure enables the millimeter wave radar system to ensure the mechanical strength and positioning accuracy of the circuit board while also taking into account the thermal path connectivity and sealing integrity, realizing the integrated assembly and maintenance convenience of multiple components. Especially in engineering scenarios with limited space and strict assembly time requirements, the unified fixing system can significantly improve the operation efficiency, reduce the risk of misinstallation, and enhance the reliability and stability of mass production.

[0062] It should be noted that the fixing method of the circuit board can also be replaced with nut column press-fitting, slot buckle connection or high-strength guide rail sliding structure to meet the maintenance and upgrade requirements of different modules; the shape of the mounting holes can be expanded from standard round holes to oblong holes, positioning holes, etc. to adapt to different expansion coefficients or thermal deformation compensation strategies; the screw type can be replaced with hexagon socket head, cross head, self-locking thread or plastic screws, etc. to improve the anti-loosening, anti-vibration and anti-short-circuit capabilities; the number and position of the fixing points can also be adjusted according to different layouts to achieve the best stress distribution and reliable grounding strategy.

[0063] Please continue to refer to Figure 1 and Figure 3 As shown, in some examples of the present invention, a J30JM connector is provided on the side of the housing 1, and the connector is connected to the interface pad on the signal and control processing circuit board by welding for realizing the power supply and serial communication connection to an external system.

[0064] In this embodiment, in order to realize the power supply and data interaction between the millimeter-wave radar altimeter and an external flight control system, data terminal or ground control platform, a standard rectangular interface opening is reserved at a specific position on the side wall of the housing 1, and an integrated J30JM connector is installed. This connector is an aviation-grade electrical connector, which has the characteristics of compact volume, interface sealing, excellent vibration resistance, etc. Its mounting flange is firmly connected to the housing 1, and the interface body passes through the structural surface of the housing 1, maintaining good positioning accuracy and mechanical strength.

[0065] On the signal and control processing circuit board, a metal pad area corresponding one-to-one to the pins of the J30JM connector is pre-designed. During the assembly process, the multi-core cable leads of the connector are respectively welded to the corresponding pad positions by manual or automatic welding methods. The welding is completed by methods such as manual drag welding with solder wire or spot welding with a temperature-controlled soldering iron. The solder joints are firm and full, ensuring reliable contact and stable conduction. After welding, visual inspection or microscopic inspection is carried out to verify the welding quality.

[0066] Through the J30JM connector, an external system can provide a stable DC working voltage to the radar altimeter structure, and realize the command control, status reading and data feedback of the device through serial communication methods (such as RS232, RS485 or TTL), forming a closed-loop data communication link. This interface also supports the anti-reverse insertion and anti-fooling structure design to avoid misconnection and damage to the module, enhancing the safety and compatibility of engineering deployment.

[0067] This connection scheme integrates the signal and power functions into a standard interface, which is beneficial to improving the interface standardization degree, wiring simplicity and environmental adaptability, and is especially suitable for the fast connection and system integration requirements in the wild and complex environments. At the same time, the J30JM connector has characteristics such as a sealing gasket and a self-tightening locking structure, ensuring the long-term stable operation of the interface under working conditions such as high humidity, high dust and high vibration.

[0068] It should be noted that the connector can be replaced with other standard aviation plugs of different models, such as D-sub, MIL-C, M12, etc., to meet the requirements of different electrical performances or installation methods; the welding method can be changed to processes such as crimping terminals, pin pressing, and cold welding to adapt to the needs of automated assembly or maintenance disassembly; the communication protocol can also be replaced with forms such as CAN, USB, SPI, etc. according to the system platform to improve data bandwidth or communication compatibility; in addition, the position of the connector can also be adjusted to the top surface or the rear cover according to the structure of the housing 1 to match the equipment installation environment or user wiring preference.

[0069] Please refer to Figure 1 , in a possible implementation, the radome 8, the heat dissipation cover plate 20 and the housing 1 are mechanically assembled through a plurality of screws. The screws sequentially pass through the structural members and the mounting holes and are locked to form a reliable assembly structure and ensure the encapsulation sealing performance.

[0070] In this implementation, to achieve the mechanical fixation and airtight protection between the structural modules of the millimeter-wave radar altimeter, a unified screw fastening method is adopted to assemble the radome 8, the heat dissipation cover plate 20 and the main housing 1. The radome 8 is used to cover the RF front-end area, and the heat dissipation cover plate 20 is used to enclose the intermediate-frequency and control circuit areas on the back of the housing 1. They are respectively provided with positioning holes. After being aligned with the preset screw holes on the housing 1, they are fastened and locked by multiple metal screws. The screw type is preferably a hexagon socket head screw with anti-loosening ability or a structural screw with a locking ring to ensure stable clamping force and connection reliability under long-term vibration conditions.

[0071] During the assembly process, while the radome 8 and the heat dissipation cover plate 20 compress the sealing ring below them, it is ensured that the compression force is evenly distributed to avoid sealing failure caused by local stress. The screws sequentially pass through the through holes at the edge of the radome 8 or the frame of the cover plate, and then pass through the structure above the sealing ring, and finally are screwed into the threaded holes of the housing 1 to form an integrated and mechanically coupled tight encapsulation structure. This fastening scheme not only realizes the integrated assembly of the RF front-end, the intermediate-frequency unit and the housing 1 as a whole, but also ensures the tightness of the internal environment of the cavity through the sealing ring structure, avoiding moisture, dust or corrosive gases from entering the cavity and affecting the operation of sensitive devices.

[0072] This implementation provides an assembly method with a simple structure, easy maintenance and reliable sealing. Through the dual effects of mechanical locking and sealing compression, without adding additional process steps, it takes into account both structural strength and environmental adaptability, and is applicable to scenarios such as aerospace and unmanned systems with high reliability requirements. It is especially suitable for engineering application occasions with high requirements for structural stability, long-term sealing and assembly consistency.

[0073] It should be noted that the screw can be replaced with a buckle, a rotary lock, a quick clamping structure, etc. to meet the requirements of tool maintenance-free or quick disassembly and assembly; the installation hole can also be designed as an elliptical guide hole, a limiting groove or a reinforcing rib structure to improve the assembly accuracy and strength; the sealing method can be extended from an O-ring to a special-shaped gasket, a foam rubber strip or a flexible edge wrapping structure to cope with different pressing force requirements and sealing grade differences; a rotation prevention boss or a positioning pin structure can be set in the structural connection area to further improve the assembly positioning accuracy and reliability.

[0074] Please refer to Figure 6 , in a possible implementation manner, to achieve the assembly of the millimeter-wave radar altimeter structure, the following manufacturing process can be referred to, including the following main steps: First, preprocess the key materials. A gold-tin alloy solder sheet can be prepared, such as the composition ratio of Au80Sn20, and a plasma cleaning device can be used to perform surface treatment on metal components such as the housing 1, the heat dissipation cover plate 20, and the gold-tin solder sheet to remove oil stains and oxide layers that may affect the subsequent welding quality, and improve the cleanliness of the joint surface and the welding reliability.

[0075] Subsequently, implement the eutectic soldering process of the chip. Pre-position the high-power transmitting chip 5 and the molybdenum-copper composite carrier plate, sandwich a gold-tin solder sheet between their contact surfaces, and heat it up to a predetermined eutectic temperature (such as about 300 °C) through a heating platform for welding. After cooling, a metal welding structure unit with excellent thermal conductivity is formed between the chip and the carrier plate.

[0076] During the sintering process of the microstrip circuit board, a high-temperature protective tape can be attached to the front of the radio frequency circuit board, the microstrip array transmitting antenna 13, and the receiving antenna 14 to prevent the solder from affecting the key components. After cleaning the groove inside the cavity for installing the circuit, apply tin-silver-copper solder in the groove, fit the circuit board and place it in a sintering device for heating to melt the solder and complete the fixation of the circuit board. After cooling, remove the protective tape, and check with a microscope and remove the solder residue with hand tools to ensure that the solder joints are clean, without short circuits or false soldering.

[0077] Set a carrier plate installation area in the cavity and apply an appropriate amount of solder, and place the chip-carrier plate structure that has completed the eutectic soldering in this area. The carrier plate and the housing 1 can be brought into thermally conductive contact through a heat treatment process to establish an outward heat conduction path for the chip.

[0078] Establish an electrical connection between the chip and the radio frequency circuit by means of wire bonding. Gold wires can be pulled between the chip pads and the circuit leads through ultrasonic ball bonding or thermocompression bonding to form an access channel for radio frequency signals. The diameter and tensile force of the gold wires, the solder joint positions, etc. can be appropriately set according to the chip packaging form.

[0079] When assembling the intermediate frequency processing circuit and the signal control circuit on the other side of the cavity, first use the combination screws to fix the intermediate frequency circuit board to the preset platform of the housing 1, and then install the spacer 17 with countersunk head screws for electromagnetic isolation. The partition 18 is used to support the signal and control processing circuit boards, and the latter is installed on the opposite side of the partition 18 by screws. The function signal path is closed by plugging the preset connectors between the circuit boards.

[0080] For the installation of the communication interface, standard industrial connectors such as J30JM can be selected, fixed to the side opening of the housing 1, and the connector pin cables are welded to the interface pads of the signal and control circuit boards by manual soldering to achieve the functions of power supply and data communication. When necessary, a protective coating can be applied to enhance the anti-oxidation and anti-vibration capabilities of the interface.

[0081] Finally, embed an O-ring in the RF unit 2 area at the front of the cavity, place the radome 8 on it and lock it with screws to form a front-end sealing structure. Similarly, install seals and the heat dissipation cover 20 in the rear signal circuit area and fix them with screws to achieve airtight sealing on both sides of the cavity. After the above steps are completed, a millimeter-wave radar altimeter assembly with a complete structure, thermal management path, sealing performance, and functional module connection can be obtained.

[0082] The parameters of each process in the above manufacturing process can be adjusted according to specific application scenarios and assembly equipment conditions. For example, the temperature curve, heating time, solder type, connector form, etc. can be flexibly configured without departing from the principle of the present invention, so as to meet different product specifications or production line requirements and ensure manufacturing quality and consistency.

[0083] The manufacturing method of the millimeter-wave radar altimeter structure involved in the present invention has an overall principle that through a manufacturing process with a clear sequence and logical closed-loop, multiple structural components, circuit components, and thermal management units with different functions and process characteristics are integrated into a unified housing 1, thereby constructing a complete radar device with high-frequency performance, electrical connectivity, thermal stability, and environmental sealing. Its working mechanism unfolds around four main lines of "heat - electricity - structure - signal". Among them, the welding of the chip realizes a high-thermal-conductivity connection between the chip and the molybdenum-copper carrier plate through the eutectic diffusion of gold and tin, ensuring a lower junction temperature under high duty cycle and high-power consumption operating environments. All metal surfaces are treated by plasma cleaning technology to remove oxide and oil film impurities, providing a clean basis for subsequent welding and sintering; the RF circuit board is bonded in the groove of the housing 1 by sintering or solder fusion process to ensure the microstrip structure fit and ground plane consistency. The key signal path is established through wire bonding technology to complete high-frequency electrical connection without introducing additional signal reflection or high-frequency impedance jump. Structural modules such as the spacer 17 and the partition 18 are assembled by screws, which not only realizes electromagnetic isolation but also provides a mounting support surface for the circuit board. The external interface 12 is welded to the circuit board pad through a standard industrial connector such as J30JM to form a power supply and communication path, and finally forms an integrated closed structure through the sealing structures on the front and rear sides and mechanical fasteners, ensuring that the radar device after assembly realizes a functional closed-loop in terms of electricity, structure, and thermal control.

[0084] Adopting the above manufacturing method has multiple technical advantages and engineering values. Firstly, this method is a standardized and processable operation path, and all operation steps can be incorporated into quality control nodes, improving product consistency while ensuring process stability, especially suitable for large-scale production. Secondly, through the eutectic welding connection method between the chip and the molybdenum-copper carrier plate, the thermal conductivity efficiency is significantly improved, effectively solving the heat dissipation bottleneck during the operation of the high-power transmitting chip 5, reducing the risk of thermal drift of the radio frequency performance caused by the junction temperature, and thus enhancing the long-term working stability and reliability of the system. Thirdly, functional isolation is achieved between circuit modules through structural separation and conductive fixation, and wire bonding ensures the integrity of the high-speed signal path, avoiding reflection losses caused by poor contact or structural discontinuity in the microwave frequency band. Further, the overall machine assembly adopts a method of pressing with multiple-point screws and a unified sealing ring to construct a front and rear symmetrically closed housing 1 system, which not only ensures electromagnetic shielding but also enhances the waterproof, dustproof, and corrosion-resistant capabilities, and can meet the environmental requirements of IP65 and above. In addition, the installation relationship between each structural component is realized by preset screw holes and positioning grooves to achieve standard alignment, improving the assembly accuracy and batch consistency and simplifying the manual operation process. Generally speaking, this manufacturing method not only meets the key index requirements of high-integration millimeter-wave radar altimeters in terms of performance, reliability, environmental adaptability, and manufacturing efficiency, but also has good engineering promotion potential.

[0085] In specific applications, each step and process parameter of the above manufacturing method can be equivalently replaced or flexibly adjusted according to different equipment types, system integration requirements, and production conditions. For example, in the eutectic soldering process, the gold-tin solder sheet can be replaced with silver sintered materials, lead-free solders, or press-fit thermal pads to meet the requirements of environmental protection materials or higher thermal conduction paths; in circuit sintering or bonding, low-temperature curing conductive silver paste, conductive foam, or anisotropic conductive film can be used to achieve the dual structural and electrical connection between the circuit module and the housing 1; for the connection between the chip and the circuit, depending on the specific packaging form, it can be replaced with flip-chip bonding, thermocompression bonding, microwave coaxial plugging, etc. structural connection solutions to adapt to the capabilities of different process production lines; the screw fixation method can also be extended to structural methods such as rail sliding, quick snap, and magnetic attraction positioning to improve the maintenance convenience; in addition to the J30JM for interface connection, D-sub, M12, aviation plugs, or high-speed backplane pluggable connectors can also be used; the sealing method can also adopt structural methods such as two-component potting, rubber overmolding, and one-piece injection molding according to different environmental levels. The above deformation and alternative solutions are all within the reasonable scope that those skilled in the art can understand and implement based on the disclosed content without affecting the core technical idea of the present invention.

[0086] In a preferred embodiment, the signal control unit 4 of the millimeter-wave radar altimeter structure is arranged inside the signal processing cavity area of the equipment housing 1. The signal control unit 4 includes an altimeter control motherboard, and the control motherboard integrates a radio frequency control module, a signal acquisition module, a signal processing module, and a general interface module. Each module is arranged in different functional areas of the motherboard in a functional division manner, constituting the core control platform of the altimeter system. The motherboard has a compact structure, and the electrical coupling paths between the modules are clear, supporting the system to complete the closed-loop control process of high-precision signal transmission, reception, processing, and altitude output within a limited space.

[0087] The radio frequency control module is used to control the working state of the radio frequency unit 2 inside the housing 1, including the transmission and echo reception of W-band frequency-modulated continuous wave signals. Through the transmission control logic, it modulates the set linear frequency modulation waveform into a W-band electromagnetic wave and transmits it to the ground; after the echo signal is reflected by the ground object and returns, the radio frequency unit 2 receives it through the antenna array and converts it into an intermediate frequency signal in analog form. The W-band has the advantages of concentrated beam, strong anti-multipath interference, and good penetration, and can maintain high signal-to-noise ratio ranging performance in complex environments such as rain, fog, and dust, improving the environmental adaptability and system robustness of the flight platform.

[0088] The signal acquisition module receives the analog echo signal output from the RF unit 2 and completes analog-to-digital conversion. This module supports two types of input paths: voltage type and current type. For the voltage type signal, it passes through the voltage detection interface, isolation amplifier, and the first voltage follower circuit in sequence and is sampled by the first AD conversion channel. For the current type signal, it is input through the current detection interface, converted into a voltage signal by the Hall sensor, enters the second voltage follower circuit for processing, and is then sampled by the second AD channel. The above dual-path design improves the adaptability and anti-interference ability of the system's front-end signal input, ensuring that high-quality digital signals can be stably obtained in different target scenarios.

[0089] After the digital signal is input, the signal processing module performs frequency domain transformation, clutter suppression, target recognition, and altitude estimation processing. This module is built based on the Zynq series FPGA chips. The FPGA chips integrate programmable logic units (PL) and embedded processor units (PS) internally, and have high throughput and high parallelism data processing capabilities. In the signal processing path, a fast Fourier transform module (FFT), a moving target detector module (MTD), a constant false alarm rate detection module (CFAR), and an α-β filtering module are integrated in sequence.

[0090] Among them, the FFT module is used to convert the time-domain beat signal into a frequency-domain spectrogram to extract the echo frequency characteristics; the MTD module eliminates the static background clutter through the velocity channel filter to highlight the dynamic target signal; the CFAR module uses the sliding window method and the sorting threshold algorithm to identify the significant target frequency points in the target spectrum. The α-β filtering module dynamically smooths the output altitude based on the target's historical state and the current observation value, using the α and β coefficients to improve the stability of the prediction result and reduce the jumps and noise interference in the altitude curve.

[0091] To adapt to different altitude measurement accuracy requirements, this processing path supports multiple frequency modulation waveform structures, including symmetric triangular waves and sawtooth waves. The system selects the calculation model of the beat frequency according to the type of transmitted waveform, and constructs the target altitude analysis equation by combining the set frequency modulation slope, waveform period, and echo time delay. In the actual spectrum processing process, to improve the frequency resolution, the system supports adding zero-value extension processing in the DFT input section to achieve spectrum interpolation and spectral line refinement, thereby improving the calculation resolution without changing the physical bandwidth, enhancing the multi-target separation ability and altitude measurement accuracy.

[0092] In addition, under the condition that the FPGA chip resources permit, the signal processing module can calculate the maximum detectable altitude according to parameters such as the maximum sampling bandwidth, system noise factor, and minimum recognizable signal-to-noise ratio, and use this result to feedback and control the transmission power level of the RF control module, ensuring that effective altitude measurement can be achieved within different combat altitude ranges, while reducing power consumption and improving the energy efficiency ratio.

[0093] The general interface module is used to complete the data interaction between the radar altitude data and the external system. Its interface circuit is located at the edge of the control motherboard and is connected to the flight control system, communication module or graphic display terminal through standard communication protocols such as UART, SPI or RS422. The external connection port adopts the J30JM military standard interface, and the data line and power supply line are integrally transmitted through a highly reliable connector. The interface module is also connected to the indicator unit. The indicator integrates a liquid crystal display screen and a multi-segment LED indicator lamp, which is used to display the current working status, target altitude value and communication status information of the device in real time, facilitating users to monitor the operation of the system and enhancing the visualization and human-computer interaction ability of the whole machine operation.

[0094] The structure of the altimeter control motherboard is a three-layer motherboard stacked layout, namely the first motherboard, the second motherboard and the third motherboard, which integrate the radio frequency control module, the signal acquisition module and the signal processing module in sequence. The three motherboards are electrically connected through high-speed board-to-board connectors and are installed and fixed on the positioning brackets in the signal processing cavity of the housing 1 through vertical structure screws. To enhance the electromagnetic isolation ability between the motherboards, an electromagnetic shielding isolation board made of metal material is set between each layer of motherboards. The isolation board adopts a copper-based nickel-plated structure or an aluminum alloy heat sink structure with a thickness of 0.8 mm to 1.2 mm, and is connected to the motherboard grounding network through a crimping method and forms a low-impedance grounding closed loop with the housing 1. This multi-layer metal shielding structure can effectively suppress the high-frequency interference and stray coupling between different functional modules, ensure the integrity of the high-speed data link and the signal quality, and meet the high-standard requirements of the avionics system for EMC performance.

[0095] In terms of structural installation, buffer and shock-absorbing gaskets made of rubber are provided at the four corners of the three motherboards respectively. After all the installation screws pass through the shock-absorbing gaskets, they are fixed on the positioning posts of the housing 1. This structure has good anti-vibration and anti-shock capabilities while ensuring the firm and reliable connection between the motherboard and the housing 1, adapts to the continuous vibration and intermittent impact generated by the UAV or aircraft platform during high-dynamic flight, and significantly improves the operation stability and durability of the whole machine.

[0096] In this embodiment, the control system organically integrates four major functional modules of radio frequency, acquisition, processing and interface in structure and drives in a closed loop logically. In terms of algorithm processing, high-order filtering, target recognition and dynamic power control strategies are introduced. Through the electromagnetic isolation of the three-layer motherboard and the mechanical anti-interference design, a set of millimeter-wave radar altimeter signal control systems with a compact structure, high processing accuracy, strong environmental adaptability and outstanding reliability are constructed, which are suitable for various high-requirement application scenarios such as complex weather, variable-speed flight and long-range altitude measurement. This structural and functional configuration has significant technical advantages over the prior art in terms of integration, EMC performance, measurement accuracy and application stability.

[0097] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0098] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A millimeter wave radar altimeter structure, characterized in that: include: A housing, wherein the housing is provided with a plurality of functional areas for integrating a plurality of functional units, wherein the plurality of functional units include at least a radio frequency unit, an intermediate frequency processing unit and a signal control unit, and the plurality of functional units are integrated in the housing in a compact layout manner, so as to reduce the size of the whole machine and improve the modularity level of the system; The radio frequency unit includes at least one high-power transmitting chip, which is mounted on a heat-conducting substrate, and the heat-conducting substrate is in contact with the housing by welding or other thermal connection methods to construct a heat conduction path, so as to effectively transfer the heat generated by the chip during operation to the housing; The shell is a structural member made of a material with excellent thermal conductivity, and a plurality of heat dissipation structures are arranged on the outside thereof to enhance the heat dissipation efficiency under natural convection conditions; The heat-conducting substrate, the shell material and the heat dissipation structure together form a continuous heat conduction path from the chip to the environment, thereby reducing the risk of heat accumulation under the highly integrated layout and ensuring the stable operation of the high-power chip; The housing further comprises a sealing structure, which comprises a sealing groove and a sealing element, and cooperates with the radome and the packaging cover to form a closed space for providing environmental protection sealing for the functional unit; The signal control unit is connected to a peripheral device via an external interface, which supports power supply and data communication for the altimeter.

2. The millimeter wave radar altimeter structure according to claim 1, characterized in that: The high-power transmitting chip is mounted on a copper carrier made of a molybdenum-copper composite material. The copper carrier is fixed in the shell by gold-tin alloy eutectic welding and is used to conduct the heat of the chip to the shell.

3. The millimeter wave radar altimeter structure according to claim 2, characterized in that: The radio frequency unit is arranged in the front functional area of ​​the shell, and includes at least one group of microstrip array transmitting antennas and at least one group of microstrip array receiving antennas, which are respectively connected to the transmitting chip and the receiving chip by gold wire bonding; the transmitting chip and the receiving chip are connected to the power supply circuit arranged inside the shell through a power division circuit, and the power division circuit is used to distribute the power supply signal to each chip, and the power supply circuit provides the working voltage required by the radio frequency unit.

4. The millimeter wave radar altimeter structure according to claim 3, characterized in that: An antenna cover is arranged above the radio frequency unit and is fixed to the corresponding area of ​​the shell by screws. The shell is provided with a sealing groove and an O-ring. The antenna cover presses the sealing ring to form a sealed antenna chamber with the shell.

5. The millimeter wave radar altimeter structure according to claim 2, characterized in that: A heat dissipation cover plate is installed on the back of the shell. The heat dissipation cover plate is in contact with the copper carrier plate through a thermally conductive gasket and is fixedly connected to the shell through screws to achieve multi-level heat conduction of chip heat to the environment.

6. The millimeter wave radar altimeter structure according to claim 1, characterized in that: The shell is provided with partition bars and partition plates. The partition bars are provided between the intermediate frequency processing circuit and the signal and control processing circuit for electromagnetic isolation. One side of the partition plate supports the intermediate frequency processing module, and the other side supports the signal processing module, forming a structural multiplexing assembly.

7. The millimeter wave radar altimeter structure according to claim 6, characterized in that: The intermediate frequency processing circuit board and the signal and control processing circuit board are fixed to the shell or the partition through preset mounting holes and a plurality of metal screws. The screws are also used to fix the copper carrier board, the antenna cover and the heat dissipation cover.

8. The millimeter wave radar altimeter structure according to claim 6, characterized in that: A J30JM connector is provided on the side of the shell, and the connector is connected to the interface pad on the signal and control processing circuit board by welding, so as to realize the power supply and serial communication connection to the external system.

9. The millimeter wave radar altimeter structure according to claim 5 and claim 7, characterized in that: The antenna cover, the heat dissipation cover plate and the housing are mechanically assembled by means of a plurality of screws, and the screws are sequentially passed through the structural parts and the mounting holes and locked, so as to form a reliable assembly structure and ensure the sealing performance of the package.

10. The method for manufacturing a millimeter wave radar altimeter structure according to any one of claims 1 to 9, characterized in that: The following steps are involved: Material pretreatment: prepare gold-tin solder sheets, and use plasma cleaning equipment to perform surface treatment on the cavity, the heat dissipation cover plate, gold-tin solder sheets and other components to remove oil stains and oxides; Eutectic welding chip: The high-power transmitting chip is eutectically welded by gold-tin alloy solder and fixed on the molybdenum-copper carrier to form a high heat conduction structural unit; Microstrip circuit board sintering assembly: attach high-temperature tape to the front of the RF circuit, the microstrip array transmitting antenna and the microstrip array receiving antenna circuit boards for protection, clean the grooves of the cavity, evenly apply tin-silver-copper solder in the grooves, fit the circuit boards in the corresponding grooves, sinter on a heating platform, remove the tape after sintering, and clean the overflow solder under a microscope; Installing the eutectic chip module: coating the eutectic chip mounting area in the cavity with lead-tin solder, placing the carrier module completed in step 2 at this position, and achieving firm welding through heat treatment; Chip connection: using the gold wire bonding method to establish an electrical connection between the high-power transmitting chip and the radio frequency circuit to form a millimeter wave signal channel; Assembly of intermediate frequency and signal module: on the other side of the cavity, the intermediate frequency processing circuit board is fixed to the housing by the combination screws, and the partition bar is fixed to the intermediate frequency processing circuit board by the countersunk screws; then the partition is fixed to the inside of the housing by screws as a mounting support for the signal and control processing circuit board, and it is fixed to the partition by the combination screws; Communication interface welding: install the J30JM connector on the side wall of the cavity, and solder the connector cable to the corresponding pad of the signal and control processing circuit board through solder wire to achieve power supply and data communication connection; Final packaging: the radome and the sealing ring are installed on the RF unit side of the cavity, and the heat dissipation cover plate and the sealing ring are installed on the signal processing module side. The radome and the heat dissipation cover plate are fastened to the cavity by screws respectively, and the sealing ring is pressed into the corresponding sealing groove of the cavity, thereby forming a complete closed sealing structure in the front and rear directions, and completing the assembly of the millimeter wave radar altimeter.

11. A control system for a millimeter wave radar altimeter as claimed in claim 1, characterized in that: The signal control unit includes an altimeter control motherboard installed inside the shell, and the altimeter control motherboard integrates a radio frequency control module, a signal acquisition module, a signal processing module and a universal interface module; the radio frequency control module is electrically connected to the radio frequency unit, and is used to control the transmission of W-band frequency-modulated continuous wave signals and the reception of echoes; the signal acquisition module is used to convert the received analog echo signals into digital signals; the signal processing module includes an FPGA module, and the FPGA module is used to perform frequency domain conversion, filtering processing and altitude estimation on the digital signals, and output the predicted altitude information to an external device or an indication module through the universal interface module.

12. The control system according to claim 11, characterized in that: The FPGA module integrates a fast Fourier transform (FFT) module, a Doppler filter (MTD) module, a constant false alarm rate detection (CFAR) module and an α-β filter module; the FFT module is used to convert the digital signal from the time domain into a frequency domain signal, the MTD module is used to suppress static clutter signals, the CFAR module is used to identify valid target echo signals, and the α-β filter module is used to smooth the target signal and output an estimated height.

13. The control system according to claim 11, characterized in that: The altimeter control motherboard is composed of a stacked first main board, a second main board and a third main board, which are respectively used to carry the radio frequency control module, the signal acquisition module and the signal processing module; the metal electromagnetic isolation board is arranged between the main boards and is integrally installed in the functional area where the signal control unit is located in the shell, so as to realize electromagnetic shielding between modules and optimize the wiring structure.

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