FMCW radio altimeter transceiver Sip integration device and method

Abstract

The invention relates to the technical field of radio altimeter Sip integration design, and discloses an FMCW radio altimeter transceiver Sip integration device and method, and the device comprises an integration box and an integrated circuit board. The integrated box comprises a shell, an upper cover plate and a lower cover plate; the upper cover plate and the lower cover plate are respectively fixed at the top and the bottom of the shell; the integrated circuit board is assembled in the integrated shell; the shell is provided with a DB15 connector, an information receiving hole and an information transmitting hole. The DB15 connector is connected to the integrated circuit board, an information receiving end and an information transmitting end of the integrated circuit board are connected with external signals through an information receiving hole and an information transmitting hole respectively, and the information receiving end and the information transmitting end are used for generating, amplifying and transmitting radio-frequency signals and carrying out amplification, frequency conversion and signal processing on the received radio-frequency signals; and outputting a height signal and an alarm signal. According to the invention, miniaturization of the FMCW radio altimeter transceiver is realized.

Description

Technical Field

[0001] This invention relates to the field of SiP integration design technology for radio altimeters, specifically to an FMCW radio altimeter transceiver SiP integration device and method. Background Technology

[0002] As a core navigation device for aircraft, missiles, and other flying vehicles, the radio altimeter's primary function is to accurately measure the aircraft's true altitude relative to the ground or sea surface in real time under complex weather conditions such as fog, rain, and snow, as well as in complex terrain environments. This provides crucial altitude reference signals for flight attitude control, mission planning and execution, and flight safety. In the field of defense weaponry, radio altimeters are particularly widely used, especially in missile weapon systems. Aircraft rely on altitude signals provided by radio altimeters to achieve predetermined altitude flight control, and their flight reliability and mission success rate directly depend on the measurement accuracy and operational stability of the radio altimeter.

[0003] With the continuous development of aerospace technology, aircraft are rapidly evolving towards integration, miniaturization, and lightweighting. The number of electronic devices they carry is constantly increasing, and the installation space between devices is becoming increasingly compact. This places higher demands on the structural design and performance indicators of radio altimeters. Currently, existing radio altimeters generally adopt a discrete structural design of "separate transmitting and receiving antenna + feeder + transceiver." This structure has gradually revealed many inherent defects in long-term use.

[0004] Specifically, existing discrete-structure radio altimeters suffer from several drawbacks. First, their low integration level results in a large overall footprint and difficulty in effectively controlling weight. This directly contradicts the "lightweight, small, and thin" installation requirements of small and medium-sized low-altitude sea-skimming aircraft, severely hindering their widespread application in such vehicles. Second, the feed lines and connection points between components in the discrete structure easily become coupling channels for electromagnetic interference, leading to poor electromagnetic interference resistance and potential decreases in measurement accuracy or even signal interruption in complex electromagnetic environments. Furthermore, the procurement, assembly, and debugging processes for discrete components are complex, increasing manufacturing costs and reducing the consistency and reliability of mass production. Therefore, developing a highly integrated, lightweight radio altimeter with strong anti-interference capabilities has become an urgent technical requirement to meet the application needs of small and medium-sized low-altitude sea-skimming aircraft. Summary of the Invention

[0005] In order to overcome the defects of the prior art, the present invention aims to provide a SIP integrated device and method for an FMCW radio altimeter transceiver, so as to solve the technical problem of how to achieve miniaturization of the FMCW radio altimeter transceiver.

[0006] This invention is achieved through the following technical solution: In a first aspect, the present invention provides an FMCW radio altimeter transceiver SIP integrated device, comprising an integrated box and an integrated circuit board; The integrated box includes a shell, an upper cover plate, and a lower cover plate; the upper cover plate and the lower cover plate are respectively fixed to the top and bottom of the shell; The integrated circuit board is assembled inside an integrated housing; the housing is provided with a DB15 connector, an information receiving hole, and an information transmitting hole; The DB15 connector is connected to the integrated circuit board. The information receiving end and information transmitting end of the integrated circuit board are connected to external signals through information receiving holes and information transmitting holes, respectively, for generating, amplifying and transmitting radio frequency signals, and amplifying, frequency converting and signal processing the received radio frequency signals, and outputting altitude signals and alarm signals.

[0007] Preferably, the integrated circuit board includes a first substrate, a second substrate, a first flexible substrate, a third substrate, a second flexible substrate, and a fourth substrate; wherein integrated circuit units are provided on the surface of the first substrate, the second substrate, and the third substrate. The first substrate is located below the second substrate and is electrically connected to the second substrate; The second substrate is located below the third substrate and is electrically connected to the third substrate through the first flexible substrate; The fourth substrate is disposed on one side above the third substrate, and the fourth substrate and the third substrate are electrically connected through the second flexible substrate. The fourth substrate has several connection holes; the DB15 connector is inserted into the several connection holes accordingly.

[0008] Furthermore, power lines, control lines, and signal lines are distributed on the first flexible substrate and the second flexible substrate.

[0009] Furthermore, the housing is provided with an isolation plate, the first substrate is located below the isolation plate, and the second substrate, the first flexible substrate, the third substrate, the second flexible substrate and the fourth substrate are located above the isolation plate. An insulating pin is provided through the isolation plate, and a pin hole is provided at the position of the insulating pin on the first substrate. The first substrate is electrically connected to the second substrate through the insulating pin.

[0010] Furthermore, a chip heat sink and an isolation wall are provided on the side of the isolation plate closest to the first substrate; The first substrate has an isolation groove at the position corresponding to the isolation wall; the isolation wall is inserted into the isolation groove and is used to isolate the transceiver circuit of the integrated circuit unit of the first substrate; The first substrate has a through hole at the position corresponding to the chip heat sink, and the chip heat sink is inserted into the through hole and then the power chip is soldered.

[0011] Furthermore, the isolation wall has a notch, and a microstrip transmission line is set at the location of the isolation groove corresponding to the notch, for providing a local oscillator signal loop to the radio frequency receiving circuit unit of the first substrate.

[0012] Furthermore, the integrated circuit unit of the first substrate includes an RF transmitting circuit board and an RF receiving circuit board; The radio frequency transmitting circuit board and the radio frequency receiving circuit board are located on both sides of the isolation groove, and the gap between the isolation groove connecting block and the isolation wall is used by the radio frequency transmitting circuit board to provide the local oscillator signal circuit for the down-conversion of the radio frequency receiving circuit board. The integrated circuit unit of the second substrate includes a three-stage power conversion circuit board, an ADC, and an intermediate frequency amplifier circuit board; The integrated unit of the third substrate includes a signal processing circuit board, an RS serial port and CAN bus circuit board, a first-level power conversion circuit board, a second-level power conversion circuit board, and a logic control and height correction circuit board.

[0013] Furthermore, mounting bosses are provided at the four corners of the upper shell of the isolation plate. The second substrate is embedded between four mounting bosses, and the third substrate has mounting holes at its four corners corresponding to the mounting bosses, and the mounting holes are fixed to the mounting bosses by screws.

[0014] Secondly, the present invention also provides a SIP integration method for an FMCW radio altimeter transceiver to obtain the aforementioned FMCW radio altimeter transceiver SIP integration device, comprising the following processes: The integrated circuit board is integrated into the housing, where the integrated circuit board is bonded to the information receiving hole and the information transmitting hole, and the information connection terminal of the integrated circuit board is soldered to the DB15 connector before debugging and testing. After the debugging and testing are passed, the upper and lower cover plates are fixed and sealed to the top and bottom of the housing using laser.

[0015] Furthermore, the integrated circuit board includes a first substrate, a second substrate, a first flexible substrate, a third substrate, a second flexible substrate, and a fourth substrate; wherein integrated circuit units are provided on the surface of the first substrate, the second substrate, and the third substrate. The specific process of integrating the first substrate, the second substrate, the first flexible substrate, the third substrate, the second flexible substrate, and the fourth substrate into the housing is as follows: The integrated circuit units on the first substrate, the second substrate, and the third substrate are soldered together and connected by the first flexible substrate and the second flexible substrate. The power chip, the first substrate, and the second substrate are soldered onto the housing, and the pads of the second substrate are soldered to the first substrate through the insulating pins of the isolation plate. The integrated circuit unit and power chip of the first substrate, as well as the information receiving end and information transmitting end of the integrated circuit unit, are connected to external signals through information receiving holes and information transmitting holes, respectively. The third substrate is fixed to the mounting boss of the isolation plate with screws; The fourth substrate and the pins of the DB15 connector are soldered by hand to complete the integration of the integrated circuit board into the housing.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: An integrated FMCW radio altimeter transceiver SiP device integrates the core circuitry of the FMCW radio altimeter transceiver into a single integrated box containing a housing and upper and lower covers. Signal interaction between the integrated circuit board and the external environment is achieved via DB15 connectors, information receiving holes, and information transmitting holes on the housing. This highly integrated and compact device can stably complete the entire process of RF signal generation, amplification, transmission, and signal amplification, frequency conversion, and processing, ensuring the accuracy of altitude and alarm signal outputs. It effectively improves the device's integration and signal processing reliability. This invention completely eliminates redundant discrete connection structures and feeder components, significantly reducing the overall space occupied by the device and the system weight. It is perfectly suited for applications with stringent size and weight requirements, such as small and medium-sized low-altitude sea-skimming aircraft, effectively overcoming the application limitations of traditional devices in such scenarios.

[0017] Furthermore, the integrated circuit board is divided into a structure composed of multiple substrates. Integrated circuit units are arranged on different substrates according to functional requirements, and electrical connections between substrates are achieved through flexible substrates. This realizes the functional zoning layout of the circuit and improves the rationality of the circuit layout. The connection holes opened on the fourth substrate are precisely matched with the DB15 connector, ensuring the accuracy and stability of the connection between the connector and the circuit board and improving the stability of signal transmission.

[0018] Furthermore, power lines, control lines, and signal lines are integrated on the first and second flexible substrates, eliminating the need for additional independent cables. This simplifies the connection structure between multiple substrates, reduces interference caused by messy wiring, ensures independent and stable transmission of different types of signals, avoids signal crosstalk, and improves signal transmission quality.

[0019] Furthermore, by setting an isolation plate inside the housing to separate the different substrates of the integrated circuit board into upper and lower regions, physical spatial isolation is achieved, effectively reducing electromagnetic interference between circuit units in different regions; the insulated pins on the isolation plate realize the electrical connection between the first substrate and the second substrate, which has both insulation and conductivity stability, avoids leakage or signal loss at the connection point, and ensures the reliability of cross-regional circuit connection.

[0020] Furthermore, by utilizing the cooperation between the isolation wall and the isolation groove on the first substrate, the transceiver circuits on the first substrate are physically isolated, effectively blocking electromagnetic interference between the transceiver circuits and improving the independence and accuracy of RF signal transmission and reception. After the chip block is inserted into the through hole of the first substrate, the power chip is attached, realizing a tight fit between the power chip and the first substrate, improving the installation stability of the power chip, while shortening the transmission path between the power chip and the circuit unit, reducing signal loss, and improving power transmission efficiency.

[0021] Furthermore, by creating a gap in the isolation wall and cooperating with the connecting block on the isolation slot, a dedicated local oscillator signal loop is constructed on the basis of achieving physical isolation between the transmitting and receiving circuits. This ensures that the local oscillator signal is stably transmitted to the radio frequency receiving circuit, providing reliable signal support for the down-conversion stage, improving the accuracy of down-conversion processing, and thus optimizing the accuracy of altitude signal calculation.

[0022] Furthermore, the integrated circuit units on each substrate are clearly functionally divided, with the RF transmitting and receiving circuit boards placed on opposite sides of the isolation slot. The directional transmission of the local oscillator signal circuit ensures the accuracy of the down-conversion of the RF receiving circuit. The three-stage power conversion circuit board, ADC, and intermediate frequency amplifier circuit board on the second substrate can adapt to different voltage requirements and improve the intermediate frequency signal processing effect. The signal processing circuit board, RS422 serial port, and CAN bus circuit board on the third substrate enrich the device's communication interfaces. The overall modular design facilitates circuit debugging, maintenance, and replacement, and improves the stability of power supply, device compatibility, and data transmission capabilities.

[0023] Furthermore, the mounting bosses on the isolation plate provide precise mounting positioning for the second and third substrates. The second substrate is embedded between the bosses, and the third substrate is fixed to the bosses with screws, ensuring the flatness and positional accuracy of the substrate installation and avoiding abnormal circuit connections caused by substrate misalignment. The screw fixing method combines convenient disassembly and assembly with strong connection, facilitating later maintenance, while improving the structural stability of the substrate inside the housing and reducing the risk of substrate loosening under vibration conditions.

[0024] This invention also provides an FMCW radio altimeter transceiver SIP integrated device. First, the integrated circuit board is bonded to the signal holes and soldered to the DB15 connector. Then, debugging and testing are performed. This allows for timely detection and correction of signal connection or circuit function abnormalities, ensuring the device's functional integrity before leaving the factory. After successful debugging, the upper and lower cover plates are laser-sealed, providing excellent sealing and effectively isolating external dust, moisture, and other impurities, improving the device's sealing performance and environmental adaptability. Furthermore, the high sealing and structural strength of laser welding ensure the overall structural stability of the integrated box.

[0025] Furthermore, the integration process for multiple substrates was refined. First, the soldering of integrated circuit units on each substrate and the connection of flexible substrates were completed to ensure reliable electrical connections between substrates. The soldering of power chips, substrates, and housings improved the installation stability of core components. The soldering connection of insulating pins ensured the conductivity of circuits across isolation boards. The screw fixing of the third substrate and the manual soldering of the fourth substrate and DB15 connector adapted to the installation requirements of different substrates. The overall process was standardized and orderly, reducing assembly errors and improving the assembly consistency and yield of the device. Attached Figure Description

[0026] Figure 1 This is a structural diagram of the SIP integrated device of the FMCW radio altimeter transceiver in an embodiment of the present invention; Figure 2 This is a structural diagram of the integrated circuit substrate in an embodiment of the present invention; Figure 3 This is a schematic diagram of the integrated shell structure in an embodiment of the present invention; Figure 4 This is a schematic diagram of the upper cavity of the integrated shell in an embodiment of the present invention; Figure 5 This is a schematic diagram of the lower cavity of the integrated shell in an embodiment of the present invention; Figure 6 This is a flowchart of the SIP integration method for the FMCW radio altimeter transceiver in an embodiment of the present invention; Figure 7 This is a functional diagram of the SIP integrated device of the FMCW radio altimeter transceiver in an embodiment of the present invention; Figure 8This is a schematic diagram of the SIP integrated device of the FMCW radio altimeter transceiver in an embodiment of the present invention; In the diagram: 1. Integration box; 2. Integrated circuit board; 11. Shell; 12. Upper cover; 13. Lower cover; 111. Isolation plate; 112. Mounting boss; 113. Insulating pin; 114. DB15 connector; 115. Information receiving hole; 116. Information transmitting hole; 117. Chip heat sink; 118. Isolation wall; 21. First substrate; 22. Second substrate; 23. First flexible substrate; 24. Third substrate; 25. Second flexible substrate; 26. Fourth substrate; 211. Isolation slot; 212. Through hole; 213. Pin hole; 214. RF transmitting circuit board; 215. RF receiving circuit board; 221. Three-stage power conversion circuit board; 222. ADC; 223. Intermediate frequency amplifier circuit board; 241. Mounting hole; 242. Signal processing circuit board; 243. RS422 serial port; 244. CAN bus circuit board; 245. Screws; 261. Connecting hole. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0028] The purpose of this invention is to provide a SIP integrated device and method for an FMCW radio altimeter transceiver, so as to solve the technical problem of how to miniaturize the FMCW radio altimeter transceiver.

[0029] The present invention will now be described in further detail with reference to the accompanying drawings: Example 1 See Figure 1In one embodiment of the present invention, an FMCW radio altimeter transceiver SIP integrated device is provided, including an integrated housing 1 and an integrated circuit board 2. The integrated housing 1 includes a shell 11, an upper cover plate 12, and a lower cover plate 13. The upper cover plate 12 and the lower cover plate 13 are respectively fixed to the top and bottom of the shell 11. The integrated circuit board 2 is assembled inside the integrated housing 1. The shell 11 is provided with a DB15 connector 114, an information receiving hole 115, and an information transmitting hole 116. The DB15 connector 114 is connected to the integrated circuit board 2. The information receiving end and the information transmitting end of the integrated circuit board 2 are connected to external signals through the information receiving hole 115 and the information transmitting hole 116, respectively, for generating, amplifying, and transmitting radio frequency signals, and amplifying, frequency converting, and processing the received radio frequency signals, and outputting altitude signals and alarm signals.

[0030] Specifically, according to Figure 2 As shown, the integrated circuit board 2 includes a first substrate 21, a second substrate 22, a first flexible substrate 23, a third substrate 24, a second flexible substrate 25, and a fourth substrate 26; wherein, integrated circuit units are provided on the surfaces of the first substrate 21, the second substrate 22, and the third substrate 24; the first substrate 21 is located below the second substrate 22 and is electrically connected to the second substrate 22; the second substrate 22 is located below the third substrate 24 and is electrically connected to the third substrate 24 through the first flexible substrate 23; the fourth substrate 26 is located above the third substrate 24 and is electrically connected to the third substrate 24 through the second flexible substrate 25; the fourth substrate 26 has a plurality of connection holes 261; the DB15 connector 114 is correspondingly inserted into the plurality of connection holes 261.

[0031] The first flexible substrate 23 and the second flexible substrate 25 are provided with power lines, control lines and signal lines.

[0032] The housing 11 contains an isolation plate 111. The first substrate 21 is located below the isolation plate 111, and the second substrate 22, the first flexible substrate 23, the third substrate 24, the second flexible substrate 25, and the fourth substrate 26 are located above the isolation plate 111. An insulating pin 113 is provided through the isolation plate 111. The first substrate 21 has a pin hole 213 at the position corresponding to the insulating pin 113. The first substrate 21 is electrically connected to the second substrate 22 through the insulating pin 113.

[0033] Specifically, according to Figure 3 , Figure 4 , Figure 5As shown, the isolation plate 111 has a chip heat sink 117 and an isolation wall 118 on the side near the first substrate 21; the first substrate 21 has an isolation groove 211 at the position corresponding to the isolation wall 118; the isolation wall 118 is inserted into the isolation groove 211 and is used to isolate the transceiver circuit of the integrated circuit unit of the first substrate 21; the first substrate 21 has a through hole 212 at the position corresponding to the chip heat sink 117, and the chip heat sink 117 is inserted into the through hole 212 and then a power chip is soldered on it.

[0034] The isolation wall 118 has a notch, and the isolation groove 211 is provided with a microstrip transmission line at the position corresponding to the notch, which is used to provide a local oscillator signal loop to the radio frequency receiving circuit unit of the first substrate 21.

[0035] Specifically, the integrated circuit unit of the first substrate 21 includes an RF transmitting circuit board 214 and an RF receiving circuit board 215; wherein the RF transmitting circuit board 214 and the RF receiving circuit board 215 are respectively located on both sides of the isolation groove 211, wherein the gap between the connecting block of the isolation groove 211 and the isolation wall 118 is used by the RF transmitting circuit board 214 to provide a local oscillator signal circuit for the down-conversion of the RF receiving circuit board 215; the integrated circuit unit of the second substrate 22 includes a three-stage power conversion circuit board 221, an ADC 222 and an intermediate frequency amplifier circuit board 223; the integrated unit of the third substrate 24 includes a signal processing circuit board 242, an RS422 serial port 243 and a CAN bus circuit board 244, a first-stage power conversion circuit board, a second-stage power conversion circuit board and a logic control and height correction circuit board.

[0036] In this embodiment, the RF transmitting circuit mainly consists of a VCO, an attenuator, a coupler, an RF power amplifier, and an RF switch. The FPGA outputs a tuning voltage, which is converted by a DAC to control the VCO to generate a 4.3GHz frequency-modulated continuous wave signal. After passing through the coupler, a portion of the signal is amplified by the RF power amplifier and then output as an RF signal with a power ≥26dBm by the RF switch. A portion of the RF signal is used as the local oscillator signal for down-converting the frequency-modulated continuous wave echo signal and input to the local oscillator terminal of the mixer in the RF receiving circuit.

[0037] The radio frequency receiving circuit consists of a radio frequency switch, a limiter, a low-noise amplifier, a mixer, etc. The echo signal returned from the ground / sea surface is amplified by the low noise and then enters the mixer. After being down-converted with the local oscillator signal, a difference frequency signal with a frequency in the kHz range is obtained.

[0038] The intermediate frequency amplifier circuit mainly consists of an intermediate frequency amplifier, a filter circuit, and an AGC amplifier circuit. It amplifies the difference frequency signal and achieves different receiving amplification gains and sensitivities corresponding to different heights with the radio frequency receiving channel.

[0039] The signal processing circuit, logic control, and altitude correction circuit consist of an FPGA, Flash, DAC, ADC, and MCU. It mainly converts analog difference frequency signals into digital difference frequency signals, performs FFT frequency precision measurement of digital difference frequency signals, smoothing filtering, search and altitude tracking status management, calculates altitude data, and obtains real-time relative altitude.

[0040] The power supply circuit consists of three levels. The first level converts the system input 28V voltage to a 10V output voltage using a DC / DC isolated power supply. The second level uses a non-isolated power supply to convert 10V to 5V, 3.3V, 1.8V, and -2V outputs to power various digital circuits. The third level uses an LDO to convert +5V to 3.3V / 1.8V / 2.5V / -0.69V outputs to power the RF circuit and intermediate frequency circuit. This fulfills the power supply requirements of various components in the transceiver.

[0041] The interface circuit mainly consists of a CAN bus / RS422 serial port and a small, airtight DB15 connector, enabling communication between the transceiver and the host computer, power supply to the transceiver, and output of altitude information. The CAN bus / RS422 serial port protocol rate is adjustable, ranging from 500kbps to 1Mbps. The functions of all electrical output ports are shown in Table 1.

[0042]

[0043] Table 1 Function Table of Electrical Lead-Out Ports The upper shell of the isolation plate 111 has four mounting bosses 112 at its four corners. The second substrate 22 is embedded between the four mounting bosses 112. The three substrate 24 has mounting holes 241 at its four corners corresponding to the mounting bosses 112. The mounting holes 241 are fixed to the mounting bosses 112 by screws 245.

[0044] In this embodiment, the integrated circuit board 2 includes a first substrate 21, a second substrate 22, a first flexible substrate 23, a third substrate 24, a second flexible substrate 25, and a fourth substrate 26; wherein, integrated circuit units are provided on the surface of the first substrate 21, the second substrate 22, and the third substrate 24; since the center frequency of the FMCW altimeter transceiver is 4.3GHz, the substrate using high-speed TG150 material meets the requirements of the operating frequency.

[0045] The digital substrate, intermediate frequency substrate, and interface substrate all use FR-4 PCB materials. The first substrate 21 is a high-frequency board, the second substrate 22 is an intermediate frequency board / power board, the third substrate 24 is a digital board / power board, and the interface board of the fourth substrate 26 is a rigid substrate. The first flexible substrate 23 and the second flexible substrate 25 are flexible substrates. The first substrate 21 is independent, the second substrate 22 and the third substrate 24 are interconnected by the flexible first flexible substrate 23, and the third substrate 24 and the fourth substrate 26 are interconnected by the second flexible substrate 25.

[0046] In this embodiment, the first substrate 21 is a multi-layer wiring RF substrate with dimensions ≤50.5mm×38.5mm×1.2mm. The front side of the first substrate 21 is designed with an RF receiving circuit and an RF transmitting circuit. The power amplifier in the RF transmitting circuit has a power consumption greater than 1W, and a through-hole 212 is designed on the first substrate 21. A metal isolation groove 211 is designed between the RF transmitting circuit and the RF receiving circuit. A through-hole 212 for a metal isolation wall is designed on the first substrate 21, and the metal isolation wall of the housing is assembled to achieve isolation between the transceiver circuits. The unisolated part in the middle is the local oscillator signal loop provided by the RF transmitting circuit for the down-conversion of the RF receiving circuit. The back side of the first substrate 21 is designed with a large area ground, which is soldered to the isolation base plate of the lower cavity of the housing through a soldering process. The power supply, control signals, intermediate frequency signals, etc. of the RF front end are transmitted by bonding with glass insulating pins.

[0047] The second substrate 22 is a multilayer irregularly shaped substrate with dimensions ≤47.15mm×38.5mm×1.2mm. The front side of the second substrate 22 is designed with a three-stage power conversion circuit, ADC, and intermediate frequency amplifier circuit. The back side of the second substrate 22 has no electrodes and is welded to the cavity isolation plate 111 on the housing 11 using a welding process.

[0048] The first flexible substrate 23 is designed to connect the power lines, control lines and signal lines of the second substrate 22 and the third substrate 24. Its size is ≤10mm×15mm×0.5mm. It is designed to be folded 180° to realize the interconnection of two rigid PCB substrates.

[0049] The third substrate 24 is a multilayer irregularly shaped substrate with PCB2 dimensions ≤ 53mm × 39mm × 1.2mm. Screw mounting holes 241 are designed at its four corners, and it is fixed to the mounting holes 112 on the four corner bosses inside the upper cavity of the outer casing by screws 245. The front and back sides of the third substrate 24 are designed with signal processing circuits, RS422 serial ports, and CAN bus circuits; the back side is designed with a first-stage power conversion circuit, a second-stage power conversion circuit, logic control, and height correction circuit.

[0050] The second flexible substrate 25 is designed with power lines, communication lines and ground lines for interconnecting the third substrate 24 and the fourth substrate 26. It is designed to be soldered at 90° to the housing DB15 to realize the interconnection of the two rigid PCB substrates.

[0051] The fourth substrate 26 is a multilayer rectangular substrate with dimensions ≤16mm×8mm×0.5mm; it is designed with solder holes for connecting to the external electrical connector DB15.

[0052] In this embodiment, the radio altimeter transceiver housing is a single upper and lower cavity structure with an isolation plate 111 in between. A three-dimensional view of the housing is shown below. Figure 3 , Figure 4 and Figure 5 As shown. The outer shell and cover are made of aluminum alloy with a metal hermetically sealed design. The partition isolation base plate is also made of aluminum alloy to improve heat dissipation.

[0053] The size of the cavity isolation base plate is ≤50.5mm×39mm×1.5mm. For power amplifiers with power consumption greater than 1W, heat dissipation is required. A through cavity is designed on the first substrate 21, and a heat dissipation boss is designed at the corresponding position on the isolation base plate. The boss has a size of 3.2mm×2.2mm×0.76mm, which improves the heat dissipation of the device and improves the performance and reliability of the radio altimeter.

[0054] The housing features external pins for an RF input signal terminal (SMP), an RF signal output terminal (SSMP), and a small, hermetic DB15 connector for electrical input / output. The SMP and SSMP pins are primarily for preventing incorrect insertion. The RF signal output terminal is located on the lower cavity housing, with an impedance of 50Ω ± 5Ω. The lower cavity is 6mm deep, and the cavity isolation plate is 1.5mm thick. The small, hermetic DB15 connector is located on the upper cavity housing. Mounting bosses and screw holes are located at the four corners of the upper cavity housing, with the center of these holes aligned with the center of the four mounting holes on PCB4. The housing cover is made of aluminum alloy and uses laser seam welding to achieve hermetic parallel seam welding, reducing weight and cost.

[0055] Example 2 according to Figure 6 As shown, this embodiment also provides a SIP integration method for an FMCW radio altimeter transceiver to obtain the aforementioned FMCW radio altimeter transceiver SIP integration device, comprising the following processes: Step 1: Solder all passive and active components on the first substrate 21, the second substrate 22 and the third substrate 24, the first substrate 21, the second substrate 22, the power chip to the isolation plate 11 and the mounting boss 112; solder the pads on the second substrate 22 to the insulating pins 113 on the isolation plate 11. Step 2: Bond the first substrate 21 to the power chip; Step 3: Bond the power chip on the first substrate 21 to the substrate, the substrate to the RF port, and the power supply port; Step 4: Fix the third substrate 24 to the holes of the mounting bosses 112 at the four corners of the upper cavity of the housing using screws 245; Step 5: Solder the pins of the fourth substrate 26 and the DB15 connector 114 by hand. Step 6: Debug and test the altimeter transceiver SIP module; Step 7: Laser seal the upper and lower cavity covers of the qualified altimeter transceiver SIP module.

[0056] A 3D model of a SIP integrated circuit for a radio altimeter transceiver is shown below. Figure 1 As shown.

[0057] In this embodiment, the FMCW radio altimeter transceiver mainly generates, amplifies, and transmits radio frequency (RF) signals, and amplifies, converts, and processes the received RF signals, ultimately outputting altitude and alarm signals. It mainly consists of components such as an FPGA, Flash memory, intermediate frequency amplifier, RF low-noise amplifier, RF mixer, RF switch, filter, RF power amplifier, RF switch, VCO, power converter, and CAN bus / RS422 interface. Functional diagrams and schematic diagrams are shown below. Figure 7 and Figure 8 As shown, the 3D model of the SiP integrated design circuit for the radio altimeter transceiver is a 3D model integrated using hybrid integration and SiP technology. In use, the system powers the radio altimeter through a DB15 interface and communicates with the system via an RS422 serial port / CAN bus through the DB15 interface. After power-on, the altimeter performs a self-test. Upon successful self-test, the FPGA controls the RF transmitting channel to transmit an RF signal to the ground / water surface. The signal reflected from the ground / water surface is converted into a digital signal by the RF receiving channel and ADC. After signal processing, logic control, and correction circuitry, the altitude information is output. The RF transmitting channel mainly consists of a frequency source (VCO), coupler, power amplifier, and RF switch. The RF receiving channel mainly consists of an RF switch, limiter, low-noise amplifier (LNA), and mixer. The microstrip line between the RF receiving channel and the transmitting channel transmits the local oscillator signal from the mixer in the receiving channel.

[0058] In summary, this embodiment employs hybrid integration technology and SiP integration technology to design an FMCW radio altimeter transceiver. Its advantages include high integration, small size, light weight, and strong anti-electromagnetic interference capability. It can provide accurate altitude information of the aircraft above the ground with extremely high precision and integrity during the approach, landing, climb, and cruise phases of the aircraft, and is widely used in aviation, aerospace, navigation, deep space exploration, and terrain matching fields.

[0059] To achieve miniaturization and weight reduction of the radio altimeter transceiver, this embodiment employs hybrid integration technology and SiP integration to design an FMCW radio altimeter transceiver circuit with a size ≤56mm×42mm×25mm. The electrical leads utilize small, hermetic DB15 connectors and SMP / SSMP microwave connectors, integrated with the housing in a hermetic design. The SMP / SSMP connectors are used for input and output of RF transceiver signals, while the DB15 connector serves as the external interface. Altitude output and altimeter status management are achieved via a CAN bus / RS422 serial port. The housing material is selected... The transceiver is made of aluminum alloy and features a dual-chamber housing design with a 1.5mm aluminum alloy isolation plate serving as the base for both chambers. Pins with glass insulators are integrated into the base plate to interconnect the upper and lower chambers, primarily for power supply, control, and intermediate frequency signals. Components with power exceeding 1W have heat dissipation bumps on the isolation base plate. Two PCB substrates are assembled on the base plate in the middle of the housing using a welding process for good grounding and heat dissipation. The excellent thermal conductivity of the aluminum alloy improves the performance and reliability of the radio altimeter transceiver. A laser-sealed hermetic assembly design enhances the transceiver's electromagnetic compatibility. Employing hybrid integrated technology and SiP design, this radio altimeter transceiver achieves altitudes from 2-1500 meters, operates at a frequency of 4.3GHz±100MHz, and features miniaturized and lightweight CAN bus / RS422 serial port data transmission. It can operate within a temperature range of -40℃ to 85℃.

[0060] This embodiment utilizes a hybrid integrated process for the SiP integrated design of a radio altimeter transceiver; high-density integration and isolation design of the RF transmitting and receiving channels; and a high-density miniaturized hermetically sealed design for the radio altimeter transceiver. This results in a radio altimeter transceiver with a height measurement range of 2-1500 meters, an operating frequency of 4.3 GHz ± 100 MHz, an operating temperature of -40℃ to 85℃, a transmit power ≥ 26 dBm, and a height measurement accuracy of 0.3 m + 3% H (H is the height value, in meters).

[0061] In this embodiment, an FMCW radio altimeter (hereinafter referred to as FMCW altimeter) transceiver, transceiver antenna and feeder combination integrated with hybrid integration process and SIP technology is used to test the relative altitude of the aircraft above the ground and sea surface. Since the measurement altitude is 0-1500 meters, the frequency modulated continuous wave mode is used. Its advantages are high altitude measurement accuracy and no distance blind zone.

[0062] The FMCW radio altimeter transceiver mainly consists of an RF transmitting circuit, an RF receiving circuit, an intermediate frequency amplifier circuit, an ADC, a signal processing circuit, logic control, altitude correction, a power conversion circuit, and an interface circuit.

[0063] The FMCW altimeter transceiver adopts a hybrid integration process and SiP design technology to achieve the integration of high-frequency, high-speed, and high-density PCB substrates. The housing is divided into upper and lower cavities by a cavity isolation base plate. The electrical leads adopt SMP / SSMP adapters and small hermetic DB15 connectors, which are integrated with the housing for hermetic packaging. This provides a new solution and approach for miniaturization and lightweighting requirements of aerospace and other systems.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An FMCW radio altimeter transceiver Sip integrated device, characterized in that, Integrating box (1) and integrated circuit board (2) are included. The integrating box (1) includes a shell (11), an upper cover plate (12) and a lower cover plate (13); the upper cover plate (12) and the lower cover plate (13) are fixed on the top and the bottom of the shell (11) respectively. The integrated circuit board (2) is assembled in the integrating shell (1); the shell (11) is provided with a DB15 connector (114), an information receiving hole (115) and an information transmitting hole (116); The DB15 connector (114) is connected to the integrated circuit board (2), and the information receiving end and the information transmitting end of the integrated circuit board (2) are connected with external signals through the information receiving hole (115) and the information transmitting hole (116) respectively, for generating, amplifying and transmitting radio frequency signals, and amplifying, frequency converting, signal processing and outputting high signals and alarm signals.

2. An FMCW radio altimeter transceiver Sip integrated device according to claim 1, characterized in that, The integrated circuit board (2) includes a first substrate (21), a second substrate (22), a first flexible substrate (23), a third substrate (24), a second flexible substrate (25) and a fourth substrate (26); wherein the board surfaces of the first substrate (21), the second substrate (22) and the third substrate (24) are all provided with integrated circuit units; The first substrate (21) is located below the second substrate (22) and is electrically connected with the second substrate (22); The second substrate (22) is located below the third substrate (24) and is electrically connected with the third substrate (24) through the first flexible substrate (23); The fourth substrate (26) is located on one side above the third substrate (24) and is electrically connected with the third substrate (24) through the second flexible substrate (25); A plurality of connecting holes (261) are formed in the fourth substrate (26); the DB15 connector (114) is correspondingly inserted into the connecting holes (261).

3. An FMCW radio altimeter transceiver Sip integrated device according to claim 2, characterized in that, The first flexible substrate (23) and the second flexible substrate (25) are provided with power lines, control lines and signal lines.

4. The FMCW radio altimeter transceiver Sip integrated device of claim 2, wherein, The shell (11) is provided with an isolation plate (111), the first substrate (21) is located below the isolation plate (111), and the second substrate (22), the first flexible substrate (23), the third substrate (24), the second flexible substrate (25) and the fourth substrate (26) are located above the isolation plate (111); An insulating pin (113) is arranged through the isolation plate (111), the first substrate (21) is provided with a pin hole (213) corresponding to the position of the insulating pin (113), and the first substrate (21) is electrically connected with the second substrate (22) through the insulating pin (113).

5. An FMCW radio altimeter transceiver Sip integrated device according to claim 4, characterized in that, The side of the isolation plate (111) close to the first substrate (21) is provided with a chip heat dissipation platform (117) and an isolation wall (118). The first substrate (21) is provided with an isolation groove (211) corresponding to the position of the isolation wall (118); the isolation wall (118) is inserted into the isolation groove (211), and the isolation wall (118) is used for isolating the transceiver circuit of the integrated circuit unit of the first substrate (21). The first substrate (21) is provided with a through hole (212) corresponding to the position of the chip heat dissipation platform (117), and the chip heat dissipation platform (117) is inserted into the through hole (212) and welded with a power chip.

6. An FMCW radio altimeter transceiver Sip integrated device according to claim 5, characterized in that, The isolation wall (118) is provided with a notch, and the isolation groove (211) is provided with a microstrip transmission line corresponding to the position of the notch, which is used for providing a local oscillator signal loop for the radio frequency receiving circuit unit of the first substrate (21).

7. An FMCW radio altimeter transceiver Sip integrated device according to claim 6, characterized in that, The integrated circuit unit of the first substrate (21) includes a radio frequency transmitting circuit board (214) and a radio frequency receiving circuit board (215). The radio frequency transmitting circuit board (214) and the radio frequency receiving circuit board (215) are respectively located on the two sides of the isolation groove (211), and the notch of the isolation wall (118) and the connecting block of the isolation groove (211) are used for providing a local oscillator signal loop for the radio frequency receiving circuit board (215) by the radio frequency transmitting circuit board (214). The integrated circuit unit of the second substrate (22) includes a three-stage power conversion circuit board (221), an ADC (222) and an intermediate frequency amplification circuit board (223). The integrated unit of the third substrate (24) includes a signal processing circuit board (242), an RS (422) serial port (243), a CAN bus circuit board (244), a one-stage power conversion circuit board, a two-stage power conversion circuit board and a logic control and height correction circuit board.

8. An FMCW radio altimeter transceiver Sip integrated device according to claim 4, characterized in that, Four corners of the upper shell of the isolation plate (111) are provided with mounting bosses (112), The second substrate (22) is embedded between the four mounting bosses (112), and the four corners of the third substrate (24) are provided with mounting holes (241) corresponding to the mounting bosses (112), and the mounting holes (241) are fixed on the mounting bosses (112) by screws (245).

9. A method of Sip integration of an FMCW radio altimeter transceiver, characterized by, An FMCW radio altimeter transceiver Sip integrated device according to any one of claims 1-8 is obtained, including the following process: The integrated circuit board (2) is integrated in the shell (11), wherein the integrated circuit board (2) is bonded with the information receiving hole (115) and the information transmitting hole in the shell (11), and the information connection end of the integrated circuit board (2) is welded and arranged with the DB15 connector (114) and then debugged and tested; When the debugging and testing are qualified, the upper cover plate (12) and the lower cover plate (13) are fixed and sealed on the top and the bottom of the shell (11) by laser.

10. The FMCW radio altimeter transceiver Sip integration method of claim 9, wherein, The integrated circuit board (2) includes a first substrate (21), a second substrate (22), a first flexible substrate (23), a third substrate (24), a second flexible substrate (25) and a fourth substrate (26); wherein the board surface of the first substrate (21), the second substrate (22) and the third substrate (24) is provided with an integrated circuit unit. The specific process of integrating the first substrate (21), the second substrate (22), the first flexible substrate (23), the third substrate (24), the second flexible substrate (25) and the fourth substrate (26) in the shell (11) is as follows: The integrated circuit units on the first substrate (21), the second substrate (22) and the third substrate (24) are welded and connected through the first flexible substrate (23) and the second flexible substrate (25); The power chip, the first substrate (21) and the second substrate (22) are welded on the shell (11), and the pads of the second substrate (22) are welded and connected with the first substrate (21) through the insulating pins (113) of the isolation plate (111); The integrated circuit units of the first substrate (21) are connected with the power chip, the information receiving end and the information transmitting end of the integrated circuit units through the information receiving hole (115) and the information transmitting hole (116) respectively; The third substrate (24) is fixed on the mounting boss (112) of the isolation plate (111) through the screw (245); The fourth substrate (26) is welded with the pins of the DB15 connector (114) by manual welding, and the integration of the integrated circuit board (2) in the shell (11) is completed.

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