A method for implementing a spaceborne scalable high-density multi-beam active array

Abstract

This invention discloses a method for implementing a spaceborne scalable high-density multi-beam active array. The array is divided into several independent subarrays based on its size, with each subarray's envelope size not exceeding the corresponding radiating aperture and possessing an independent electrical interface. The subarrays are modularly designed, each including a radiating element layer, a T / R component layer, and a multi-beamforming network layer. The multi-beamforming network layer has a BGA-packaged T / R component layer, and the T / R component layer is stacked with radiating element layers. All subarrays are assembled onto a power combining network module to form a complete active array. This invention solves the key challenges of high design difficulty and long customization development cycles for large-scale, ultra-high-density multi-beam phased arrays on spaceborne systems.

Description

Technical Field

[0001] This invention relates to a method for implementing a spaceborne scalable high-density multi-beam active array, belonging to the field of microwave design technology. Background Technology

[0002] Ka-band multi-beam active phased array antennas, as one of the core payloads of low-Earth orbit (LEO) satellites, primarily function to form multiple independent high-gain beams through antenna elements, enabling ubiquitous access and multi-point communication, offering advantages such as high flexibility and wide-angle scanning. Due to the high operating frequency, small element spacing, and large number of elements, traditional spaceborne multi-beam phased array antennas often employ a combination of several single-beam antennas to achieve multi-beam functionality, or a brick-and-tile approach. The core T / R components use a brick-like architecture to achieve amplitude and phase control and signal amplification for multiple channels and beams, while the synthesizing network uses an independent tile-like structure. The disadvantages of these solutions are significant product size, weight, and power consumption. Given the urgent need for miniaturization and lightweighting of LEO satellites, these solutions are insufficient, necessitating a tile-like architecture to achieve multi-beam functionality. However, conventional tile-like architectures require metal connectors for electrical interconnection between different modules, resulting in low integration and poor manufacturability for mass production, failing to meet the demand for rapid mass production of hundreds of LEO satellites in the short term.

[0003] Currently, the most commonly used airborne or missile-borne phased array architecture is the watt-type architecture, which integrates the antenna array, RF power combining / distribution network, and low-frequency circuitry into a single unit based on multilayer microwave dielectric substrate technology. The RF active circuitry is packaged and mounted on the back of the multilayer substrate. Ground-based applications using this approach are primarily single-beam applications. The disadvantages of this approach are: due to the long transmission path of the RF signal through the multilayer substrate, the loss is significant, directly affecting the antenna system's G / T or EIRP values. Changes in antenna type or array size for different applications necessitate design changes and circuit redesigns, resulting in poor scalability and reconfigurability, severely impacting product delivery schedules and incurring high development costs. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a method for realizing a spaceborne scalable high-density multi-beam active array. By rationally dividing the subarray and making innovative designs for the subarray, the key problems of high design difficulty and long customized development cycle of spaceborne large-scale ultra-high-density multi-beam phased arrays are solved.

[0005] The technical solution of this invention is:

[0006] A method for implementing a spaceborne scalable high-density multi-beam active array includes:

[0007] The array is divided into several independent subarrays according to the size of the active array. The envelope size of each subarray does not exceed the corresponding radiating surface aperture and has an independent electrical interface.

[0008] The subarrays are modularly designed, each subarray including a radiating unit layer, a T / R module layer, a multi-beamforming network layer, a T / R module layer with BGA packaged on the surface of the multi-beamforming network layer, and a radiating unit layer stacked on the surface of the T / R module layer.

[0009] All subarrays are assembled onto the power combining network module to form a complete active array.

[0010] Preferably, the radiating unit layer includes a multilayer substrate, one side of which is covered with a metal layer as a ground plane, and the other side is formed with a metal patch of a predetermined shape, which is fed to form an antenna.

[0011] Preferably, the T / R component layer adopts a multi-layer high-temperature co-fired ceramic or silicon-based package. Based on the integrated package and wiring design, the ceramic shell or silicon substrate serves as both the package and the carrier for circuit layout cavities and wiring. Multiple amplifier chips are integrated in the front cavity, and a multi-beam amplitude and phase control multifunctional chip is integrated in the back cavity. Electrical interconnection is achieved through gold wire bonding and three-dimensional vertical interconnection. At the same time, several RF pads are integrated on the front of the package for electrical connection with the radiating unit layer, and several RF and low-frequency pads are integrated on the back for electrical interconnection with the beamforming network.

[0012] Preferably, the multi-beamforming network layer is based on a multi-layer substrate design, with the front and back sides designed as external interfaces. The radio frequency networks, low-frequency power supply and distribution, and control circuits distributed in each layer are all stripline designs. The striplines in the same layer are isolated by shielded ground holes on both sides, and the striplines in different layers are isolated by a large area of ​​metal ground between the layers.

[0013] Preferably, in the multi-beamforming network layer, the front side of the multilayer substrate integrates several low-frequency and RF pads for electrical connection with the T / R component layer; the back side of the multilayer substrate realizes the output of multiple beam RF interfaces of the subarray to the outside through RF connectors, and realizes external low-frequency interconnection through low-frequency connectors.

[0014] Preferably, the beamforming network layer is based on a multilayer substrate and is combined with polytetrafluoroethylene prepreg through multiple pressings to realize a high-low frequency hybrid circuit board integrating a multi-beamforming network and low-frequency power supply control.

[0015] Preferably, in each subarray, the radiating element layer, T / R component layer, and multibeamforming network layer are electrically connected using BGA ball-mounting, specifically including:

[0016] First, balls are placed on the back of the radiating unit layer. Then, balls are placed on the bottom of the T / R module layer. Finally, the beamforming network layer, T / R module layer and radiating unit layer are stacked in three dimensions, and the electrical assembly is completed by a reflow soldering process.

[0017] Preferably, the radiating unit layer, the T / R component layer, and the beamforming network layer are all metallized.

[0018] Preferably, the method for assembling all subarrays onto the power combining network module to form a complete active array is as follows:

[0019] The RF connectors, low-frequency connectors, and power combining network modules of each subarray are simultaneously plugged into each other for interconnection;

[0020] Each subarray is fixed to the housing of the power combining network module through the mounting holes on the back of each subarray.

[0021] Preferably, to meet the application requirements of different satellite orbits, the design of the radiation unit layer of each subarray is modified according to the application requirements, while the T / R component layer and beamforming network layer remain unchanged, so as to achieve rapid mass production.

[0022] The advantages of this invention compared to the prior art are:

[0023] (1) This invention divides a large-scale ultra-high density array into subarrays, which are two-dimensionally scalable, reducing the difficulty of array design and realizing the architecture design of complex high-integration arrays.

[0024] (2) The present invention is based on a modular design for the subarray, which is divided into three independent parts: the radiation unit layer, the T / R component layer, and the multi-beam network layer. Different functions can be achieved by optimizing the design of the corresponding functional layers to meet the needs of different users, thus shortening the development cycle and making it suitable for platform products.

[0025] (3) The T / R component layer designed in this invention achieves the shortest path connection with the radiating unit layer and beamforming network layer in terms of electrical performance through double-sided cavity and double-sided ball-mounting, thus possessing excellent transmission characteristics. At the same time, it achieves hermetically sealed packaging of bare chips based on system-in-package technology, meeting the requirements for high-reliability applications in space environments. Attached Figure Description

[0026] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0027] Figure 1 This is a schematic diagram of the scalable subarray architecture of the present invention;

[0028] Figure 2 This is a schematic diagram of the array distribution according to an embodiment of the present invention;

[0029] Figure 3 This is a block diagram illustrating the principle of receiving a phased array subarray according to an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the layered beamforming network according to an embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of the receiving phased array subarray structure according to an embodiment of the present invention;

[0032] Figure 6 This is a schematic diagram of the receiving phased array structure according to an embodiment of the present invention. Detailed Implementation

[0033] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0034] A method for implementing a spaceborne scalable high-density multi-beam active array is proposed. First, the array is divided into subarrays based on its size. The division principle ensures the array can be arbitrarily expanded in two dimensions, requires the envelope size of each subarray to not exceed the corresponding radiating aperture, and necessitates that each subarray has an independent electrical interface for easy integration between subarrays. The subarray is divided into three functional layers, as illustrated in the layered architecture diagram below. Figure 1 As shown, the layers are divided into three functional layers: radiation unit layer, T / R component layer, and multi-beamforming network layer.

[0035] The radiating element layer is based on a multilayer substrate design. One side has a metal layer attached as a ground plane, and the other side is formed into a metal patch of a certain shape. The patch is fed using microstrip lines or coaxial probes to form an antenna. By optimizing the antenna pattern, good radiation characteristics and polarization isolation can be achieved. At the same time, the conformal design of the antenna and the structure makes it easy to achieve low profile characteristics. The multilayer substrate can be a composite dielectric substrate or a low-temperature co-fired ceramic or a high-temperature co-fired ceramic.

[0036] The T / R module layer adopts multi-layer high-temperature co-fired ceramic (HTCC) or silicon-based packaging. Based on the integrated packaging and wiring design, the ceramic shell or silicon substrate serves as both the package and the carrier for circuit layout and wiring. It integrates multiple low-noise amplifier chips, power amplifier chips, and multi-beam amplitude and phase control multi-functional chips. The electrical interconnection within the module is achieved through gold wire bonding and three-dimensional vertical interconnection. Combined with the sealing and soldering process, the module's hermeticity is ensured, meeting the high reliability requirements of spaceborne application environments.

[0037] The multi-beamforming network layer is based on a multi-layer substrate design, with the front and back sides designed as external interfaces. The complex RF network and low-frequency power distribution circuits are all stripline designs. The power divider network circuit adopts the Wilkinson form. Striplines in the same layer are isolated by shielded ground holes on both sides, while striplines in different layers are isolated by large-area metal ground between layers, improving the EMI (electromagnetic interference) characteristics between channels and between beams.

[0038] The main body of the subarray is a multi-beamforming network. The electrical connections between the radiating element layer, the T / R component layer, and the multi-beamforming network layer are all achieved using a BGA (Ball Grid Array) ball-mounting method. The multi-beamforming network surface is electrically mounted with BGA-packaged T / R components, and the radiating element layer is stacked on top of the T / R components. Using BGA ball-mounting facilitates high-density interface integration, avoiding traditional metal connectors and offering convenience and speed. The radiating element layer, T / R component layer, and beamforming network layer all undergo metallization edge treatment to prevent crosstalk between signals after large-scale array integration.

[0039] Taking a Ka-band 768-element 4-beam receiving phased array as an example, the present invention will be described in detail: The Ka-band receiving phased array antenna adopts a system architecture based on AOP stacked packaging, with a total of 768 elements and extremely small element spacing. Traditional architecture layouts are difficult to achieve large-scale high-density integration within a limited space. Based on the design of the present invention, the entire antenna array is divided into 8 subarrays, each with 96 elements. Each subarray is independent of the others, and the array distribution is as follows. Figure 2 As shown. The subarray is divided into three functional layers. Figure 3 The diagram shows the principle of the subarray, with the radiating element, receiving component, and beamforming network arranged sequentially from the signal flow direction.

[0040] The radiating element layer is based on a TSM-DS3 (polyester fiber + glass fiber + ceramic) multilayer substrate, employing a dual-resonant microstrip element design as a printed circuit board coupled antenna. Each substrate integrates 2*2 antenna elements, utilizing a second-order lamination and sidewall metallization process, ensuring independent fabrication and testability. To facilitate the integration of the radiating element, receiving component, and beamforming network, and considering device layout and spaceborne reliability, the receiving component adopts a double-sided cavity and double-sided ball-mounted HTCC design. The receiving component uses a high-precision HTCC ceramic alumina tube package, achieving an integrated tube layout design. High-efficiency parallel seam welding is used for sealing, achieving hermetically sealed packaging while ensuring electromagnetic shielding, meeting the high reliability requirements of spaceborne applications. Each receiving component corresponds to 4 antenna elements: a front cavity integrating 4 low-noise amplifiers, and a rear cavity integrating a 4-input 4-output amplitude and phase multifunction amplifier. External interfaces are integrated on both sides of the component. The front integrates multiple RF pads for electrical connection with the radiating element layer, while the rear integrates several RF and low-frequency pads for electrical interconnection with the beamforming network. The beamforming network layer is based on a TSM-DS3 multilayer substrate, combined with FR-28-0040-50 (PTFE) prepreg through multiple lamination processes, realizing a high-low frequency hybrid circuit board integrating a multi-beamforming network and low-frequency power supply control. The stack-up structure uses a 22-layer board, and the stack-up relationship is as follows: Figure 4 As shown. RF signals are located on layers 1, 6, 10, 14, 18, and 22, with inter-layer interconnection achieved through metallized vias K1 to K6. Low-frequency (power and control) signals are located on layers 2, 3, and 4, with interconnection achieved through metallized vias K1 and K16. The remaining vias are ground vias, providing good signal shielding. The total thickness of the printed circuit board is approximately 4.0 mm. The front side of the beamforming network substrate integrates several low-frequency and RF pads for electrical connection to the receiving components. The back side of the substrate uses surface-mount SSMP connectors to output the four external beam RF interfaces of the subarray. The low-frequency interfaces use surface-mount micro-rectangular connectors for external low-frequency interconnection.

[0041] The receiver phased array subarray integration employs a two-stage stacking of BGA balls (450um high-lead solder balls) and a single-stage soldering process. First, balls are placed on the back of the radiating element layer; second, balls are placed on the bottom of the receiving component; finally, the beamforming network layer, receiving component, and radiating element layer are stacked in three dimensions. Electrical assembly can be completed in a single reflow soldering operation. This integration method does not involve micro-assembly processes and offers rapid mass production capability. The dimensions of a single subarray are 63.6mm * 42mm * 17mm (including subarray mounting feet and connector height). A schematic diagram of the subarray structure is shown below. Figure 5 As shown, it weighs 94g, with a single channel weighing less than 1.0g. Its volume and weight are significantly reduced compared to traditional brick-type structures, only 1 / 30 of the traditional design.

[0042] The array can be expanded into a complete active array using eight subarrays, employing a cable-free assembly design. An array integration diagram is shown below. Figure 6 As shown. The entire array consists of 8 subarrays and 1 power combining network module. Each subarray has 4 RF connectors and 1 low-frequency connector that are simultaneously plugged into and interconnected with the power combining network to achieve electrical connection of RF and low-frequency signals. The subarrays are fixed to the power combining network housing through 4 mounting holes on the back of the subarrays to achieve structural integration. The guide design of the KK connector at the plug end of the power combining network ensures the plugging accuracy of the RF connectors (the low-frequency connector body has guide posts).

[0043] After actual testing, the product demonstrated excellent electrical performance. Furthermore, to meet the application requirements of different low-Earth orbit satellites, only different types of radiating elements need to be optimized; the remaining circuit layers of the subarray are of a universal design, allowing for mass production and repeated deployment. Based on the rapid production at the subarray level, the economic and development cycle costs of the entire active array meet the overall satellite requirements of speed, intelligence, and affordability.

[0044] The embodiments described above are merely preferred embodiments of the present invention. Ordinary variations and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for implementing a spaceborne scalable high-density multi-beam active array, characterized in that, include: The array is divided into several independent subarrays according to the size of the active array. The envelope size of each subarray does not exceed the corresponding radiating surface aperture and has an independent electrical interface. The subarrays are modularly designed, each subarray including a radiating unit layer, a T / R component layer, a multi-beamforming network layer, a T / R component layer with BGA package on the surface of the multi-beamforming network layer, and a radiating unit layer stacked on the surface of the T / R component layer. All subarrays are assembled onto the power combining network module to form a complete active array; The radiating unit layer includes a multilayer substrate, one side of which is attached with a metal layer as a ground plane, and the other side is formed with a metal patch of a predetermined shape. The metal patch is fed to form an antenna. The T / R component layer adopts multi-layer high-temperature co-fired ceramic or silicon-based packaging. Based on the integrated packaging and wiring design, the ceramic shell or silicon substrate serves as both the package and the carrier for circuit layout cavities and wiring. Multiple amplifier chips are integrated in the front cavity, and a multi-beam amplitude and phase control multi-functional chip is integrated in the back cavity. Electrical interconnection is achieved through gold wire bonding and three-dimensional vertical interconnection. At the same time, several RF pads are integrated on the front of the package for electrical connection with the radiating unit layer, and several RF and low-frequency pads are integrated on the back for electrical interconnection with the beamforming network. The multi-beamforming network layer is based on a multi-layer substrate design, with the front and back sides designed as external interfaces. The radio frequency networks, low-frequency power supply and distribution, and control circuits distributed in each layer are all stripline designs. The striplines in the same layer are isolated by shielded ground holes on both sides, and the striplines in different layers are isolated by a large area of ​​metal ground between the layers.

2. The method for implementing a spaceborne scalable high-density multi-beam active array according to claim 1, characterized in that, In the multi-beamforming network layer, the front side of the multilayer substrate integrates several low-frequency and RF pads for electrical connection with the T / R component layer; the back side of the multilayer substrate realizes the output of multiple beam RF interfaces of the subarray to the outside through RF connectors, and realizes external low-frequency interconnection through low-frequency connectors.

3. The method for implementing a spaceborne scalable high-density multi-beam active array according to claim 1, characterized in that, The beamforming network layer is based on a multilayer substrate and is combined with polytetrafluoroethylene prepreg through multiple laminations to realize a high-low frequency hybrid circuit board that integrates a multi-beamforming network and low-frequency power supply control.

4. The method for implementing a spaceborne scalable high-density multi-beam active array according to claim 1, characterized in that, Within each subarray, the radiating element layer, T / R component layer, and multibeamforming network layer are electrically connected using BGA ball-mounting, specifically including: First, balls are placed on the back of the radiating unit layer. Then, balls are placed on the bottom of the T / R module layer. Finally, the beamforming network layer, T / R module layer and radiating unit layer are stacked in three dimensions and then electrical assembly is completed by one reflow soldering.

5. The method for implementing a spaceborne scalable high-density multi-beam active array according to claim 1, characterized in that, The radiating unit layer, T / R component layer, and beamforming network layer are all metallized and edge-bound.

6. The method for implementing a spaceborne scalable high-density multi-beam active array according to claim 1, characterized in that, The method for assembling all subarrays onto the power combining network module to form a complete active array is as follows: The RF connectors, low-frequency connectors, and power combining network modules of each subarray are simultaneously plugged into and interconnected. Each subarray is fixed to the housing of the power combining network module through the mounting holes on the back of each subarray.

7. The method for implementing a spaceborne scalable high-density multi-beam active array according to claim 1, characterized in that, To meet the application requirements of different satellite orbits, the design of the radiation unit layer of each subarray is modified according to the application requirements, while the T / R component layer and beamforming network layer remain unchanged, enabling rapid mass production.

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