Direct-radiation array antenna

Abstract

A direct radiating array antenna is provided, which is a DRA antenna for transmitting or receiving RF signals in a predetermined frequency band, comprising: a plurality of radiating elements defining a radiation surface of the DRA antenna; a plurality of RF signal chain paths; and a single beam forming network having a plurality of electrical ports electrically connected to the RF signal chain paths, each of the RF signal chain paths being coupled to one of the radiating elements, each of the radiating elements amplifying the transmitted or received RF signal.

Description

Technical Field

[0001] The following generally relates to antennas and antenna assemblies for radio frequency (RF) communication. More specifically, it relates to a direct radiating array antenna.

Background Art

[0002] The number of connected devices and the traffic between them continue to increase. Furthermore, the data generated by these devices has also increased rapidly, so the demand for communication systems that support such communication is also increasing. One way to support such communication is through communication satellites. As the launch of satellites becomes easier and satellite-based communication increases, the market for communication satellites is growing rapidly.

[0003] Communication satellites support communication through on-board antennas. One such antenna is an active direct radiating array antenna. By using this type of antenna, size, mass, and power can be managed and balanced. Antennas that achieve one or more of miniaturization, weight reduction, and low power consumption, or antennas that may trade off performance while managing size, mass, and power, have often been sought. For example, in satellite-borne applications, the total weight allocated to the antenna may be limited. In this case, the number of radiating components and the electrical efficiency of the antenna are restricted.

[0004] The frequency band of communication signals continues to widen, and the amount of beams propagating signals also continues to increase. Therefore, especially in low Earth orbit (LEO) applications, it will become increasingly difficult to increase the number of mechanical and electrical components concentrated in the locations adjacent to the array while maintaining antenna efficiency. Since LEO requires more DRA (direct radiating array) scans, the spacing between components (i.e., the spacing between radiating components) will become narrower. Therefore, LEO is more difficult to implement than GEO and MEO in terms of the concentration of mechanical and electrical components. Furthermore, in order to reduce signal loss between different components, it is necessary to make the signal path length as short as possible. Therefore, such components need to be arranged as close to the array as possible.

[0005] To prevent a temperature rise that may cause an overall decrease in antenna efficiency, it is also required to efficiently manage the heat generated in antenna components such as signal amplifiers. Therefore, a structure for dissipating the heat generated in the antenna components is required. However, such a structure can cause the complexity of the entire antenna. As a result, the weight of the antenna (for example, a direct radiating array antenna) increases. This may have an adverse effect on the electrical performance of the antenna.

[0006] As a result of the strict structural requirements of the antenna (for example, radiating components, signal amplification path, heat dissipation structure, etc.), the physical size may increase. This increases the weight of the antenna and may reduce the available space inside the spacecraft. In satellite-borne applications, the total weight allocated to the antenna may be limited. In this case, the number of radiating components and the electrical efficiency of the antenna may be limited.

Summary of the Invention

Problems to be Solved by the Invention

[0007] Therefore, in order to solve at least one problem of the current direct radiating array system and method, an improved direct radiating array antenna and a method for manufacturing the same are needed.

Means for Solving the Problems

[0008] A DRA antenna (Direct Radiating Array Antenna) is provided for transmitting or receiving RF signals (radio frequency radio signals) in a predetermined frequency band. This DRA antenna includes a plurality of radiating elements that define the radiating surface of the DRA antenna, a plurality of RF signal chain paths, and a single beamforming network including a plurality of electrical ports electrically connected to the RF signal chain paths. Each of the RF signal chain paths is coupled to one of the radiating elements respectively, and is characterized in that each of the radiating elements amplifies the RF signal transmitted or received.

[0009] Each of the RF signal chain paths may include heat generating components, The DRA antenna may include a heat spreader that passively cools the DRA antenna by transferring the heat generated by the heat generating components in the RF signal chain paths.

[0010] Each of the RF signal chain paths may include heat generating components, The DRA antenna may include a plurality of heat blades that passively transfer the heat generated by the heat generating components.

[0011] Each of the heat blades may include an upper surface that functions as a heat exchange interface of the DRA antenna.

[0012] Each of the heat blades may include a heat pipe that passively or actively transfers heat.

[0013] The heat pipe may be a vibrating heat pipe that passively transfers heat.

[0014] Each of the heat blades may be a solid metal heat blade that passively transfers heat.

[0015] The DRA antenna further includes a plurality of radiating element modules, Each of the radiating element modules includes a subset of a plurality of radiating elements and a subset of a plurality of RF signal chain paths, Each of the subsets of the radiating elements defines a collective radiating element bottom surface, Each of the subsets of the RF signal chain paths may be included inside the collective radiating element bottom surface.

[0016] The DRA antenna further includes a plurality of SIP modules (system-in-package modules), Each of the SIP modules includes at least one BFIC (beamforming integrated circuit), The SIP module may be attached to a planar beamforming network board.

[0017] A first subset of the SIP modules is attached to a first surface of the beamforming network board, A second subset of the SIP modules is attached to a second surface of the beamforming network board, The first surface and the second surface may face each other.

[0018] The SIP module is attached to the beamforming network board as a plurality of double stacks, Each of the double stacks includes a first SIP module attached to a first surface of the beamforming network board and a second SIP module attached to a second surface of the beamforming network board, The first SIP module and the second SIP module may be connected to each other.

[0019] Each of the double stacks may be thermally coupled to a heat blade that passively conducts heat.

[0020] The first subset of the SIP module may dissipate heat generated in itself and at least one second subset of the SIP module.

[0021] Each of the first subsets of the SIP module may be thermally coupled to a heat blade that passively conducts heat.

[0022] The beamforming network is attached to a base plate, Each of the double stacks is thermally coupled to the base plate, The base plate may transfer heat from the heat generating components of the double stack to a heat blade for passively conducting heat.

[0023] The subsets of the SIP each comprise a cover, The cover may function as a heat exchange interface for heat generated by the heat generating components of the SIP module.

[0024] The subsets of the SIP each comprise a cover, The cover may contact the base plate of the DRA antenna and transfer heat generated by the heat generating components of the SIP module to the base plate.

[0025] Each of the RF signal chain paths may be connected to the beamforming network board via a spring-loaded electrical connector.

[0026] The DRA antenna further comprises a plurality of SIP modules (system-in-package modules) attached to the beamforming network board, The SIP module may include at least one BFIC (beamforming integrated circuit) and a spring-loaded electrical connector that connects the SIP module to the beamforming network.

[0027] The beamforming network board defines a first surface, The RF signal chain path may be disposed on a second plane substantially perpendicular to the first plane.

[0028] The DRA antenna further includes a plurality of heat blades mounted substantially perpendicular to the beamforming network board, The plurality of RF signal chain paths may be attached to the plurality of heat blades.

[0029] A satellite provided with the above DRA antenna is provided. This satellite may be a low Earth orbit satellite.

[0030] A spacecraft bus, The DRA antenna according to claim 1 attached to the spacecraft bus, An OBP (on-board processor) communicably connected to the DRA antenna according to claim 1, Comprising, A satellite is provided, wherein the OBP processes a beam signal provided to the beamforming network board or a beam signal received from the beamforming network board.

[0031] A spacecraft bus, The above DRA antenna attached to the spacecraft bus, A satellite comprising is provided.

[0032] A method of operating the above DRA antenna is provided. This method is characterized by comprising the step of transmitting or receiving an RF signal in at least one predetermined frequency band using the DRA antenna.

[0033] A DRA antenna for transmitting or receiving a radio frequency electromagnetic wave signal in a predetermined frequency band is provided. This antenna, Comprises a plurality of radiating element modules, Each of the plurality of radiating element modules, A plurality of radiating elements defining at least one radiating surface of the DRA antenna, A plurality of RF signal chain paths, comprising, each of the RF signal chain paths is coupled to one of the radiating elements respectively, and amplifies the RF signals transmitted or received by each of the radiating elements, the plurality of radiating elements define a collective radiating element bottom surface, the plurality of RF signal chain paths are characterized by being included inside the collective radiating element bottom surface.

[0034] The DRA antenna further comprises a plurality of heat spreaders, each of the plurality of RF signal chain paths may include a heat generating component attached to each of the heat spreaders for passively transferring the heat generated by the heat generating component to the heat spreader.

[0035] The DRA antenna further comprises a single beamforming network board for implementing a beamforming network, the beamforming network board may comprise a plurality of electrical ports for electrically connecting to the plurality of RF signal chain paths.

[0036] The beamforming network board may transfer all RF signals, electrical signals, and DC power to the plurality of RF signal chain paths of the DRA antenna.

[0037] The plurality of radiating elements and the plurality of RF signal chain paths are assembled into a radiating element module, each of the radiating element modules has a subset of the plurality of radiating elements and RF signal chain paths coupled together, the subset of the radiating elements may be arranged linearly.

[0038] The DRA antenna further comprises a single beamforming network board for implementing a beamforming network, the beamforming network board comprises a plurality of electrical ports for electrically connecting to the plurality of the plurality of RF signal chain paths, The radiation element module may be arranged substantially perpendicular to the beamforming network board.

[0039] The DRA antenna further comprises a plurality of heat blades. The radiation element module is attached to the heat blade. The heat generated by each heat generating component of the RF signal chain path may be passively transferred to each of the heat blades.

[0040] The radiation element module is attached to the plurality of heat blades. At least one radiation element module is attached to the first surface of the heat blade. At least one radiation element module may be attached to the second surface on the opposite side of the first surface of the heat blade.

[0041] The RF signal chain path may include a driver before high power amplification in the DRA antenna, or a gain block for low noise amplification in the DRA antenna.

[0042] Each of the plurality of RF signal chain paths may be electrically connected to the beamforming network board via a spring-loaded electrical connector.

[0043] The plurality of heat spreaders are heat blades. Each heat blade may include a heat pipe.

[0044] The heat pipe may be a vibrating heat pipe.

[0045] The DRA antenna further comprises a plurality of system-in-SIP modules (system-in-package modules) attached to the beamforming network board. Each of the SIP modules may include a beamforming integrated circuit and a spring-loaded electrical connector for electrically connecting to the beamforming network board.

[0046] A DRA antenna is a DRA antenna that transmits or receives radio frequency signals in a predetermined frequency band, a single beamforming network board, and a plurality of SIP modules (system-in-package modules), each including a BFIC (beamforming integrated circuit). The SIP module may be mounted flat on the beamforming network board.

[0047] A first subset of the plurality of SIPs is attached to a first surface of the beamforming network board, a second subset of the plurality of SIPs is attached to a second surface of the beamforming network board, and the first surface and the second surface may face each other.

[0048] The plurality of SIP modules are attached to the beamforming network board as a plurality of double stacks, and each of the double stacks includes a first SIP module attached to a first surface of the beamforming network board and a second SIP module attached to a second surface of the beamforming network board. The first SIP module and the second SIP module may be connected to each other.

[0049] Each of the double stacks may be thermally coupled to a heat blade that passively conducts heat.

[0050] The beamforming network is attached to a base plate, and each of the double stacks is thermally coupled to the base plate. The base plate may transfer heat to a heat blade for passively transferring heat from the heat generating components of the double stack.

[0051] Each subset of the SIPs includes a cover, The cover may function as a heat exchange interface for the heat generated by the heat generating components of the SIP module.

[0052] Each subset of the SIPs includes a cover, The cover may contact the base plate of the DRA antenna and transfer the heat generated by the heat generating components of the SIP module to the base plate.

[0053] A satellite equipped with the above DRA antenna is provided. This satellite may be a low Earth orbit satellite.

[0054] A spacecraft bus, The above DRA antenna attached to the spacecraft bus, A satellite comprising is provided.

[0055] A method of operating the DRA antenna of, A method characterized by comprising the step of transmitting or receiving an RF signal in at least one predetermined frequency band using the above DRA antenna is provided.

[0056] A spacecraft bus, An on-board processor, A DRA antenna connected to the on-board processor and attached to the spacecraft bus, comprising, The DRA antenna, A plurality of radiating elements defining a radiating surface of the DRA antenna, A plurality of RF signal chain paths, A single beamforming network comprising a plurality of electrical ports electrically connected to the RF signal chain paths is provided. Each of the RF signal chain paths is coupled to one of the respective radiating elements and amplifies the RF signals transmitted or received by each of the radiating elements, and a satellite is provided.

[0057] The satellite further includes a passive thermal management subsystem that manages the heat generated by the DRA antenna. The passive thermal management subsystem includes a plurality of heat blades connected to a heat sink. The heat blades may actively or passively transfer the heat generated by the heat generating components of the DRA antenna to the heat sink.

[0058] The satellite may be a low Earth orbit satellite.

[0059] The satellite may further include a positioning subsystem that controls the orbit of the satellite. The orbit may be a low Earth orbit.

[0060] A spacecraft bus, An on-board processor, A DRA antenna connected to and attached to the on-board processor, Comprising, The DRA antenna, A plurality of radiating element modules defining at least one radiating surface of the DRA antenna, A plurality of RF signal chain paths coupled to each of the radiating element modules and amplifying the RF signals received by or transmitted to the radiating elements, The plurality of radiating elements define a collective radiating element bottom surface, The RF signal chain paths are provided within the collective radiating element bottom surface, and a satellite is provided.

[0061] The satellite further includes a passive thermal management subsystem that manages the heat generated by the DRA antenna. The passive thermal management subsystem includes a plurality of heat blades connected to a heat sink. The heat blade may actively or passively transfer the heat generated by the heat generating component of the DRA antenna to the heat sink.

[0062] The satellite may be a low Earth orbit satellite.

[0063] The satellite may further include a positioning subsystem for controlling the orbit of the satellite. The orbit may be a low Earth orbit.

[0064] A DRA antenna for transmitting or receiving an RF signal (radio frequency radio signal) in a predetermined frequency band, A DRA antenna is provided, which is characterized by comprising a single beam forming network board.

[0065] The DRA antenna further includes a plurality of RF signal chain paths, The beam forming network board may transfer all RF signals, electrical signals, and DC power to the RF signal chain paths.

[0066] A method of manufacturing a DRA antenna (direct radiating array antenna), generating a first assembled heat blade by attaching a first plurality of radiating element modules to a first heat blade; attaching a beam forming network board to a base plate; attaching the first assembled heat blade to the base plate such that the first assembled heat blade is substantially perpendicular to the beam forming network board; comprising A method is provided, wherein the attaching step includes forming an electrical connection between each electrical connector of the first plurality of radiating element modules and a corresponding receiving port of the beam forming network board.

[0067] The first thermal blade and the first plurality of radiating element modules may be arranged substantially perpendicular to the beam forming network board.

[0068] At least one radiating element module is attached to the first surface of the first thermal blade, At least one radiating element module is attached to the second surface of the first thermal blade, The first surface and the second surface may face each other.

[0069] The method includes forming a second assembled thermal blade by attaching a second plurality of radiating element modules to a second thermal blade that actively or passively conducts heat, attaching the second assembled thermal blade to the base plate such that the first assembled thermal blade is substantially perpendicular to the beam forming network board and substantially parallel to the first assembled thermal blade, and further comprising The attaching step may include forming an electrical connection between each electrical connector of the second plurality of radiating element modules and a corresponding receiving port of the beam forming network board.

[0070] The first thermal blade and the second thermal blade may be of the same size.

[0071] The electrical connector may be a spring-loaded electrical connector.

[0072] Each of the first plurality of radiating element modules includes a plurality of radiating elements and a plurality of radio frequency ( "RF") signal chain paths, Each of the RF signal chain paths is coupled to a corresponding one of the plurality of radiating elements, The plurality of radiating elements define a collective radiating element bottom surface, The RF signal chain paths may be included inside the collective radiating element bottom surface.

[0073] The entire plurality of RF signal chain paths may be included inside the bottom surface of the collective radiation element.

[0074] The first plurality of radiation elements may be centrally attached to the first heat blade.

[0075] The first plurality of radiation element modules include a plurality of radiation elements arranged linearly, a plurality of RF signal chain paths, and each of the plurality of radiation elements is attached to another plurality of radiation element modules, each of the RF signal chain paths is coupled to one of the plurality of radiation elements and may amplify a signal received by the radiation element or a signal applied to the radiation element.

[0076] The electrical connector may be a spring-loaded electrical connector.

[0077] The spring-loaded electrical connector may provide a DC and RF interface to the beamforming network board.

[0078] The first heat blade may include an upper surface that functions as a heat exchange interface for the DRA antenna.

[0079] The first heat blade may include a heat pipe.

[0080] The step of forming the first assembled heat blade may further include the step of attaching a beam amplification module ("BAM"), and the step of forming an electrical connection between the electrical connector of the BAM and a corresponding receiving port of the beamforming network board. and

[0081] The electrical connector may be a spring-loaded electrical connector.

[0082] Further comprising the step of attaching a first plurality of system-in-package (SIP) modules to the first surface of the beamforming network board, The first SIP module may include at least one beamforming integrated circuit.

[0083] Further comprising the step of attaching a second plurality of SIP modules to the second surface of the beamforming network board, The second SIP module includes at least one beamforming integrated circuit, The first surface and the second surface may face each other.

[0084] The first plurality of SIP modules may be thermally coupled to the base plate to transfer heat from the heat-generating components of each of the first plurality of SIP modules to the first heat blade.

[0085] The base plate may couple heat to the first heat blade.

[0086] A DRA antenna for transmitting or receiving radio frequency (RF) signals in a predetermined frequency band, A single beamforming network board, and A plurality of SIP modules (system-in-package modules), each including a BFIC (beamforming integrated circuit), The SIP module is provided with a DRA antenna, characterized in that it is mounted flat on the beamforming network board.

[0087] A DRA antenna for transmitting or receiving radio frequency (RF) signals in a predetermined frequency band, A single beamforming network board, and A plurality of SIP modules (system-in-package modules), each including a BFIC (beamforming integrated circuit), The SIP module is linearly attached to the beamforming network board and is electrically connected to the beamforming network board via a spring-loaded electrical connector, and a DRA antenna is provided.

[0088] A DRA antenna for transmitting or receiving radio frequency radio signals in a predetermined frequency band, A single beamforming network board, A plurality of SIP modules (system-in-package modules), each including a BFIC (beamforming integrated circuit), Each of the SIP modules includes a spring-loaded electrical connector for electrically connecting to the beamforming network board, and a DRA antenna is provided.

[0089] A DRA antenna for transmitting or receiving radio frequency radio signals in a predetermined frequency band, Comprising a plurality of radiating element modules, Each of the plurality of radiating element modules, A radiating element that defines a radiating surface of the DRA antenna, An RF signal chain path coupled to the radiating element and amplifying an RF signal received by or transmitted to the radiating element, A spring-loaded electrical connector for connecting the RF signal chain path to a beamforming network board of the DRA antenna, And a DRA antenna is provided.

[0090] A DRA antenna for transmitting or receiving radio frequency radio signals in a predetermined frequency band, Comprising a plurality of radiating element modules, Each of the plurality of radiating element modules, A plurality of radiating elements defining a radiating surface of the DRA antenna, A plurality of RF signal chain paths, Comprising, Each of the plurality of RF signal chain paths is coupled to the radiating element and amplifies an RF signal received by or transmitted to the radiating element, The plurality of radiating elements define a collective radiating element bottom surface, The DRA antenna is provided, wherein the RF signal chain path is included inside the collective radiating element bottom surface.

[0091] A DRA antenna for transmitting or receiving a radio frequency electromagnetic wave signal in a predetermined frequency band, A beamforming network board, A plurality of radiating element modules, Comprising, Each of the radiating element modules, One radiating element defining a radiating surface of the DRA antenna, One RF signal chain path coupled to the radiating element and amplifying an RF signal received by or transmitted to the radiating element, Comprising, The DRA antenna is provided, wherein the RF signal chain path is arranged substantially perpendicular to the beamforming network board.

[0092] A DRA antenna for transmitting or receiving a radio frequency electromagnetic wave signal in a predetermined frequency band, A beamforming network board, An RF signal chain path arranged substantially perpendicular to the beamforming network board, The DRA antenna is provided, characterized in that it comprises the above.

[0093] A DRA antenna for transmitting or receiving a radio frequency electromagnetic wave signal in a predetermined frequency band, One beamforming network board defining a first surface, A plurality of RF signal chain paths disposed on the second surface, comprising, A DRA antenna is provided, wherein the first surface and the second surface are substantially perpendicular to each other.

[0094] A DRA antenna for transmitting or receiving radio frequency electromagnetic wave signals in a predetermined frequency band, One beamforming network board, A plurality of heat blades, A plurality of RF signal chain paths, comprising, The plurality of RF signal chain paths amplify RF signals received by or transmitted to connected radiating elements and are attached to their respective corresponding heat blades. A DRA antenna is provided, wherein the plurality of heat blades are disposed substantially perpendicular to the beamforming network board.

[0095] A DRA antenna for transmitting or receiving radio frequency electromagnetic wave signals in a predetermined frequency band, One beamforming network board, A plurality of heat blades, comprising, A DRA antenna is provided, wherein each of the plurality of heat blades uses a heat pipe to passively transfer heat generated by heat generating components of the DRA antenna to a heat sink.

[0096] A DRA antenna for transmitting or receiving radio frequency electromagnetic wave signals in a predetermined frequency band, One beamforming network board, A plurality of heat blades for passively cooling the DRA antenna by transferring heat generated by heat generating components of the DRA antenna to a heat sink, A DRA antenna is provided, characterized in that it comprises.

[0097] A DRA antenna for transmitting or receiving radio frequency signals in a predetermined frequency band, One beamforming network board, A plurality of radiation element modules including a plurality of radiation elements and a plurality of RF signal chain paths, Comprising, The plurality of RF signal chain paths are coupled to the corresponding plurality of radiation elements and amplify RF signals received by or transmitted to the plurality of radiation elements, The plurality of RF signal chain paths are included inside the collective radiation element bottom surface defined by the plurality of radiation elements, The plurality of RF signal chain paths are arranged substantially perpendicular to the beamforming network board, and a DRA antenna is provided.

[0098] A DRA antenna for transmitting or receiving radio frequency signals in a predetermined frequency band, One beamforming network board, A first SIP module and a second SIP module each having at least one beamforming integrated circuit, Comprising, The first SIP module and the second SIP module are attached to opposite surfaces of the beamforming network board and are connected to each other so that the first SIP module provides a heat exchange interface for the second SIP module, and a DRA antenna is provided.

[0099] Other aspects and features will become apparent to those skilled in the art by reading the description of some typical embodiments below.

Brief Description of Drawings

[0100] The accompanying drawings are for the purpose of illustrating various examples of the technology, methods, and apparatuses in this specification.

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DETAILED DESCRIPTION OF THE INVENTION

[0122] Hereinafter, various devices or processes will be described in order to explain examples of each embodiment described in the claims. The embodiments described below do not limit the embodiments described in the claims. The embodiments described in the claims can cover processes or devices different from those described below. The embodiments described in the claims are not limited to devices or processes having all the features of the devices or processes described below, nor are they limited to features common to a plurality of devices or processes described below.

[0123] The following generally relates to antenna-based communication systems, and more specifically to DRA antennas (Direct Radiating Array Antennas). The DRA antennas of this specification can be smaller than conventional DRA antennas. Thereby, advantageously, size, cost, and / or mass can be reduced. These can be important elements for realizing DRA antennas in space-based applications. Furthermore, by miniaturizing the design of the DRA antenna, active heat generating components can be placed in a more concentrated area, so temperature management of the generated heat becomes a weight feature. The DRA antennas of the present disclosure enable an approach that can keep the temperature of components within an acceptable range through such heat management.

[0124] In certain embodiments of the present disclosure, the DRA can be used for low Earth orbit (LEO) satellites. LEO may expand the requirements for DRA scans. Therefore, this may narrow the spacing between the elements of the DRA (as described later, the spacing between elements refers to the spacing between radiating elements within the active lattice of radiating elements). Since the spacing between the elements of the DRA used in LEO needs to be narrower, from the perspective of closely concentrating mechanical or electrical components, the realization of LEO applications is more difficult than that of geostationary orbit or medium Earth orbit. The DRA of the present disclosure solves the problems when closely arranging the mechanical or electrical components of the DRA, and is particularly suitable for use in LEO satellites.

[0125] The present disclosure relates to a DRA antenna including active radiating elements (i.e., radiating elements equipped with RF signal paths and amplifiers). In some embodiments, the DRA antenna of this specification may include one or more passive radiating elements in addition to one or more active radiating elements (however, the description and illustration of such passive radiating elements may be omitted). Therefore, in the present disclosure, a DRA antenna including only active radiating elements and a DRA antenna including a combination of active radiating elements and one or more passive radiating elements are described. In this case, just because there is no mention of passive radiating elements does not mean that the possibility of their inclusion or use in the DRA antenna is excluded.

[0126] FIG. 1 shows a system 100 for satellite-based satellite communication according to an embodiment.

[0127] System 100 includes a terrestrial segment 102 and a space segment 104.

[0128] The space segment 104 of system 100 includes communication satellites 110a, 110b, and 110c. In this specification, generally, communication satellites 110a, 110b, and 110c are collectively referred to as communication satellites 110.

[0129] System 100 may include any number (i.e., one or more) of communication satellites 110. In certain embodiments, communication satellite 110 is a low Earth orbit (LEO) satellite. In another embodiment, communication satellite 110 may be a medium Earth orbit (MEO) satellite or a geostationary (GEO) satellite. In embodiments where system 100 includes multiple satellites 110, the satellites 110 may collectively be referred to as a satellite constellation or a satellite network.

[0130] Each of communication satellites 110a, 110b, and 110c includes a DRA antenna (direct radiating array antenna) subsystem (this subset is respectively DRA antenna subsystems 112a, 112b, and 112c). In this specification, generally, DRA antenna subsystems 112a, 112b, and 112c are collectively referred to as DRA antenna subsystem 112. DRA antenna subsystem 112 may be configured to perform RF transmission, RF reception, or both.

[0131] In certain embodiments, DRA antenna subsystem 112 may operate in the Ku band or the Ka band.

[0132] DRA antenna subsystem 112 includes a direct radiating array. The direct radiating array may be an active array (e.g., one including a DC-powered circuit, an amplifier beamforming integrated network, etc.). The direct radiating array is configured to perform analog beamforming.

[0133] Communication satellites 110a, 110b, and 110c communicate with each other via an inter-satellite communication link 114.

[0134] The ground segment 102 includes a gateway earth station (GES) 106 (or gateway station 106). The system 100 may include a plurality of gateway stations 106, which are located at different positions. The gateway station 106 may be located on the ground surface, in the atmosphere, or in outer space. The gateway station 106 may be fixed or movable.

[0135] The gateway station 106 (whether ground-based or atmosphere-based) includes one or more devices configured to communicate with the satellite 110 in real time.

[0136] Communication satellites 110a, 110b, and 110c communicate with the gateway station 106 via communication links 118a, 118b, and 118c, respectively.

[0137] The gateway station 106 is configured to establish a telecommunication link 108 with the satellite 110 when the satellite 110 is within the "field of view" of the gateway station 106. The gateway station 106 transmits (and / or) receives RF signals (radio wave signals) to (and / or) from the satellite 110. The gateway station 106 may include a parabolic antenna for transmitting and receiving RF signals. The gateway station 106 may be fixed or orbiting.

[0138] The gateway station 106 sends RF signals (uplink) to the satellite 110 via the communication link 108 and receives transmitted data from the satellite 110 (downlink) via the communication link 108.

[0139] The gateway station 106 may function as a command or control center for a satellite network (or "satellite constellation").

[0140] The gateway station 106 may analyze the data received from the satellite 110 and / or relay the received data to another location (i.e., another computer system such as another gateway station 106) for analysis. In some cases, the gateway station 106 may receive data from the satellite 110 and transmit the received data to a computer device (particularly one configured to perform processing and analysis of the received satellite data).

[0141] Furthermore, the gateway station 106 may be configured to receive data from the satellite 110 and monitor the navigation or position of the satellite 110 (e.g., altitude, movement), or monitor the functionality of critical systems of the satellite (e.g., by analyzing data from the critical systems to be monitored).

[0142] The gateway station 106 may include one or more of the following elements: a system clock, an antenna system, a transmit and receive RF device, a telemetry tracking command (TT&C) device, a data-user interface, a mission data recovery device, and one or more elements of the station control center.

[0143] The ground segment 102 of the system 100 also includes user terminals 108.

[0144] The user terminals 108 may be fixed or mobile. The user terminals 108 may be any device capable of transmitting and / or receiving RF communication signals. The user terminals 108 include an RF communication module for transmitting and / or receiving RF signals. The user terminals 108 may be computer devices such as, for example, laptops, desktops, or mobile devices (e.g., smartphones).

[0145] Communication satellite 110c communicates with user terminal 108 via communication link 116. The communication performed by satellite 110c via communication link 116 may include transmission and reception. FIG. 1 shows communication link 116 established between satellite 110c and user terminal 108. However, user terminal 108 may establish a similar communication link with satellite 110a or 110b. Similarly, satellite 110c may establish a similar communication link with other user terminals.

[0146] FIG. 2 shows communication satellite 110 of FIG. 1 according to an embodiment.

[0147] Communication satellite 110 includes satellite bus 202. Satellite bus 202 provides the body of satellite 110. Satellite bus 202 provides the location of payloads (such as various subsystems like DRA antenna subsystem 112), the structural support and the base structure of satellite 110. The components of communication satellite 0 may be housed inside satellite bus 202 or connected (directly or indirectly via other components) to the outer surface of satellite bus 202.

[0148] Communication satellite 110 includes a propulsion subsystem 206 for driving communication satellite 110. Propulsion subsystem 206 includes one or more actuators such as reaction wheels and thrusters. Propulsion subsystem 206 may include one or more engines for generating propulsion force.

[0149] Communication satellite 110 includes a positioning subsystem 208. Positioning subsystem 208 uses special sensors (such as direction measurement sensors) to obtain sensor data. Such sensors may be used by the processing unit of positioning subsystem 208 to determine the position of satellite 110. Positioning subsystem 208 controls the altitude and orbit of satellite 110. Positioning subsystem 208 communicates with propulsion subsystem 206.

[0150] The positioning subsystem 208 and the propulsion subsystem 206 determine and apply the torques and forces necessary to orient the satellite 110 to the desired altitude, keep the satellite 110 in the correct orbital position, and keep the antenna (e.g., the direct radiating array antenna 222) in the correct direction.

[0151] The communication satellite 110 includes a power subsystem 210. The power subsystem 210 supplies power to the DRA subsystem and other components. The power may be supplied by solar panels on the satellite bus 112, which convert solar radiation into current. The power subsystem 210 may also include a battery for storing energy to be used when the satellite 110 is in the Earth's shadow.

[0152] The satellite 110 includes a command and control subsystem 212. The command and control subsystem 212 includes electronic circuitry for controlling the data communicated between the components of the communication satellite 110. The propulsion subsystem 206, the positioning subsystem 208, and the power subsystem 210 may each be communicatively connected to the command and control subsystem 212 to send and receive data therebetween.

[0153] The communication satellite 110 includes an OBP (on-board processor) 214. The OBP 214 may be part of the satellite's payload. The OBP 214 communicates with the DRA subsystem 112. The on-board processor 214 may be a digital playback subsystem. Alternatively, the DRA subsystem may be used with a digital transmission subsystem or an analog transmission subsystem, and the "on-board processor" may refer to the digital transmission system of the analog transmission system.

[0154] OBP214 may include a beam output port for outputting a beam signal to a beamforming module (also referred to as a "beamforming network") of the DRA subsystem 112. The beam signal may be transmitted to a beam amplification module ("BAM"). OBP214 may be configured to generate a beam signal and output the beam signal to the beamforming module via the beam output port. OBP214 may include a beam input port for receiving a beam signal output from the beamforming module of the DRA subsystem 112. OBP214 may be configured to receive a beam signal from the beam input port via the beam input port and process the received beam signal.

[0155] The communication satellite 110 also includes a temperature control subsystem (or temperature management subsystem) 216. The temperature control subsystem 216 controls, manages, and regulates the temperature of one or more components of the communication satellite 110 within an acceptable range. This may include maintaining similar components at a substantially uniform temperature. For example, the temperature control subsystem 216 may manage the temperature of any component in these subsystems by managing the heat generated by the active heat sources (heat generating components) of the subsystems 206, 208, 210, 212, and 112. The temperature control subsystem 216 may include, for example, any of a heater strip, paints and coatings that absorb heat from the earth and the sun, heat pipes, and heat sinks. Generally, the temperature control subsystem 216 may protect the electronic components of the DRA subsystem 112 and other subsystems from external temperatures due to intense sunlight, lack of solar exposure on the opposite side of the satellite body, self-heating of the DRA subsystem (i.e., heat generating components of the DRA subsystem), etc. The temperature control subsystem 216 may include active components or passive components.

[0156] The communication satellite 110 may include other payload subsystems 226. The other payload subsystems 226 may include any of an optical inter-satellite terminal, a gateway antenna, a filter, a cable, and a waveguide.

[0157] Communication satellite 110 includes a DRA subsystem 112. The DRA subsystem 112 includes a DRA assembly 222 and a DRA controller ("DRAC") 224. The DRA assembly 222 and the DRAC 224 are communicatively connected so that they can transmit signals to each other. The DRA assembly 222 and the DRAC 224 are each communicatively connected to the OBP 214. The DRA subsystem 112 may be a class of beamformers having at least 10 beams and at least 500 radiating components. The number of beams and the number of radiating components define the complexity (number of nodes) of the DRA beamforming network.

[0158] The DRA assembly 222 may be a receiving (Rx) antenna or a transmitting (Tx) antenna. The communication satellite 110 may include RxDRA and TxDRA subsystems 112. There may be one DRAC 224 for each DRA 222 (for example, the first DRAC exists for a certain RxDRA and the second DRAC exists for a certain TxDRA). Each of the DRACs 224 is connected to the OBP 214. The communication satellite 110 may include a plurality of RxDRA assemblies and / or a plurality of TxDRA assemblies. In a variant, the communication satellite 110 may include a plurality of DRA assemblies 222 or DRA subsystems 112 (which may be Tx or Rx or both). The number of DRA subsystems 112 or DRA assemblies on the communication satellite 110 is not particularly limited. In a specific embodiment, the communication satellite 110 includes two RxDRA assemblies 222 with two polarization waves and two TxDRA assemblies 222 with two polarization waves.

[0159] The DRA assembly 222 transmits and / or receives RF radio wave signals within a predetermined signal frequency band. The DRA assembly may be configured to use a certain subset of the entire signal bandwidth.

[0160] In Tx, the DRA assembly 222 receives the signal from the OBP 214, generates a plurality of beams, and supplies the beams to the RF radiation elements for transmission. In Rx, this process is reversed with appropriate modifications.

[0161] The DRA assembly 222 includes a beamforming module for performing analog beamforming operations. By the beamforming operation, the array of RF radiation elements can transmit RF signals in a specific direction and minimize the power radiated in other directions (i.e., the DRA can set the radiation in a certain direction to zero to prevent interference). Each of the radiation elements in the array can have a signal to be transmitted respectively. Therefore, the phase and (possibly) the intensity of each signal can be added constructively or destructively. As a result, the energy can be concentrated in a narrow beam or lobe and minimize the transmission in other directions. Depending on the design, the intensity control may be optional. The signals transmitted (or received) by the radiation elements are controlled by the BFIC (beamforming integrated circuit) element of the beamforming module.

[0162] The DRAC 224 is communicatively connected to the DRA 222 assembly and the OBP 214 and may transmit (or receive) signals to (or from) any of them. The DRAC 224 may be part of the DRA assembly 222. For example, the DRAC 224 may be formed on the beamforming module (e.g., the beamforming module 302 in FIG. 3) of the DRA assembly 222. Advantageously, by adopting such a configuration, the DRA can be miniaturized, lightened, and made more efficient.

[0163] DRAC224 is applied to configure and control the DRA assembly 222. In particular, DRAC224 is applied to configure and control the beamforming network of DRA222 (e.g., the beamforming module 302 in FIG. 3). Through this configuration and control, the OBP214 may be enabled to control analog beamforming, beam hopping, and terrestrial cell beam tracking. DRAC224 may be configured to transmit beam hopping commands to a beamforming integrated circuit (e.g., BFIC310 in FIG. 3) to implement beam hopping.

[0164] DRAC224 manages the operation of the DRAC assembly 222 and provides a digital interface to the OBP214. The digital interface may be the sole digital interface of the DRA subsystem 112 with the OBP214. DRAC224 may be an interface to the OBP214 via a dual redundant CAN bus for commands, control, and telemetry.

[0165] DRAC224 receives commands from the OBP214 and provides telemetry to the OBP214.

[0166] As described above, DRAC224 provides an interface to the BFIC of the DRA assembly 222. DRAC224 may be an interface to the BFIC via a set of serial buses (which may be operated simultaneously for parallel division of beam coefficients). DRAC224 may control the BFIC via a plurality of daisy-chain connections along the serial bus.

[0167] DRAC224 may store a set of beam list tables ("BLT"). The BLT stores beam grids, shapes, and center frequencies of various sizes in a non-volatile memory flash device.

[0168] DRAC224 may assist in a beam hopping sequence with a programmable number of independent hops.

[0169] DRAC224 may assist with a beam hopping sequence with programmable duration time slots.

[0170] DRAC224 may assist with the loading of the BLT to the BFIC of the BLT via a beam index (BLI) message that specifies a BLT list for the hopping sequence under the control of OBP214.

[0171] DRAC224 may assist with terrestrial cell tracking updates in integer time slots as commanded by OBP214 (or as automatically calculated based on terrestrial cell position).

[0172] DRAC224 may assist with the mute and sleep modes of the DRA assembly 222 for DC power savings. The sleep mode may be applied to any of the BFIC, BAM, and the radiating element modules of the module by shutting down the power regulator (e.g., EPC320).

[0173] DRAC224 may support the application of adjustment factors to the BLT at the frequency center.

[0174] DRAC224 may support updates on the track of the BLT and the tuning table.

[0175] DRAC224 may provide OBP214 with redundant CAN buses (e.g., A and B) and an Epoch synchronization interface, and may provide a set of serial buses for the interface with the BFIC of the DRA assembly 222.

[0176] DRAC224 may include circuitry directly incorporated on the BFN PCB. DRAC224 may operate in a single-string configuration, may operate in a dual cold redundancy configuration, or may operate in a dual hot redundancy configuration. All of these operate under the control of OBP214.

[0177] Figure 3 shows the DRA assembly 222 of FIG. 2 according to an embodiment. The DRA assembly 222 may be a transmit ("Tx") DRA or a receive ("Rx") DRA.

[0178] Generally, the DRA 222 may be a phased array antenna including a set of antennas or radiating elements 316. This is created such that the radiation pattern of each radiating element 316 is constructively combined with adjacent radiating elements 316 to form an effective radiation pattern called the main lobe. The main lobe transmits radiation energy at a desired position. On the other hand, the DRA 222 is designed to destructively interfere with signals in an unwanted direction and set the signals to zero, generating side lobes. The DRA antenna 222 may be designed to maximize the energy radiated by the main lobe and attenuate the energy radiated by the side lobes to an acceptable level. The direction of radiation may be manipulated by changing the phase of the signal applied to each antenna element 316. As a result, each antenna element 316 in the array has different phases and intensities, forming a desired radiation pattern. The DRA assembly 222 uses a semiconductor integrated circuit-based phase adjustment element to change the direction of the radiation pattern.

[0179] The DRA assembly 222 may be a broadband communication antenna. The DRA assembly 222 may be a class of beamforming antennas having 10 or more beams. The DRA assembly 222 may transmit or receive multiple (e.g., 16) simultaneous beams.

[0180] The DRA assembly 222 may be a direct radiating antenna array that covers the Ka band or the K band. The DRA assembly 222 may be a TxDRA in the frequency band of 17.3 GHz - 21.3 GHz. The TxDRA may use a subset of this frequency band. The DRA assembly 222 may be an RxDRA in the frequency band of 27 GHz - 31 GHz. The RxDRA may use a subset of this frequency band. Each of the DRA 222 may have single circular polarization (i.e., LHCP or RHCP) or dual polarization (i.e., LHCP or RHCP).

[0181] The DRA assembly 222 is configured to transmit or receive a plurality of simultaneous beams (which can progress, be formed, and hop independently). The number of beams is 10 or more. In certain embodiments, the number of beams is 16 or more. The DRA assembly 222 performs analog beamforming. This has an arbitrary beam diameter, an arbitrary beam shape, and an arbitrary beam boresight.

[0182] The DRA includes a beamforming module 302 for performing analog beamforming. The beamforming module 302 may be used to perform phase and (if possible) intensity adjustment at RF frequencies. The beamforming module 302 may include a DRAC (e.g., DRAC 224).

[0183] The BFN module 302 includes a beamforming network board (BFN board) 304. The BFN board 304 provides a structure and organization for components mounted on the surface of the BFN board 304. The BFN board 304 is a printed circuit board (the "PCB"). The BFN board 304 may be a multilayer PCB. The BFN board 304 provides RF, DC, and digital signal routing between components of the DRA assembly 222 mounted (or connected) to the BFN board 304. The BFN board 304 is desirably a single board of flat shape. Beamforming components (e.g., the following SIP module 308) may be mounted on the BFN board 304. In this case, the mounted beamforming components define a plane that is substantially parallel to the plane defined by the BFN board 304. The beamforming components may be mounted on the opposite side of the BFN board 304.

[0184] The BFN board 304 has various active components connected via interconnects. The active components may include the following BAM 306, SIP module 308, and radiating element 312. The SIP module 308 is mounted on the BFN board 304.

[0185] The BFN board 304 may provide the required different DC levels to each active component. The BFN board 304 may route digital signals from the DRAC to the SIP module 308.

[0186] The active components may be connected to the BFN board 304 by spring-loaded electrical connectors. The SIP module 308 may use a spring-loaded connector interposer to connect to the BFN board 304.

[0187] The layout of the BFN board 304 may be optimized for the placement of the SIP module 308 and for the temperature management of the active heat generating components. The layout of the SIP module 308 on the BFN board 304 may be optimized to facilitate routing and to minimize performance degradation. The layout of the SIP module 308 on the BFN board 304 may be optimized for a back-to-back mechanical attachment of the SIP module 308 (double stack configuration).

[0188] The BFN board 304 may consist of multiple layers of high-frequency laminate material. The high-frequency laminate may be a ceramic-filled PTFE composite material. The layered material provides high RF performance. The layers may be adhered using fusion bonding.

[0189] The BFN board 304 may be substantially symmetric in the xy plane and may be divided into quadrants.

[0190] The BFN board 304 is configured to route the beam input RF signal from the OBP (e.g., OBP 214) to the BAM 306. The BFN board 304 is configured to route the output from the BAM 306 (beam input signal) to the SIP module 308 which controls the beam and its phase and intensity as well as the radiating elements. The BFN board 304 is further configured to route the RF output of the SIP module 308 to the designated radiating element module 312. In the Rx configuration, the BFN board 304 may be configured to perform the aforementioned routing in the reverse direction.

[0191] The beamforming module 302 includes a SIP module 308. The SIP module 308 is attached to and electrically connected to the BFN board 304. The electrical connection to the BFN 304 is shown by the interconnect 326 in FIG. 3. This supports communication between the SIP module 308 and other components of the DRA assembly 222. The beamforming module 302 may include any number of SIP modules suitable for the application. There is no particular limitation on this number. The SIP module 308 may be attached to the opposite sides (e.g., top and bottom) of the BFN board 304.

[0192] The SIP module 308 may include M×N beamforming nodes. In this case, the DRA 222 has M beams and N×32 radiating elements.

[0193] Each of the SIP modules 308 is configured to receive a beam input signal. The SIP module 308 adjusts the intensity and phase of each beam with respect to each connected radiating element. For example, in Tx, the SIP module 308 separates each beam into 8 radiating elements and integrates 16 beams into each radiating element.

[0194] The SIP module 308 has an RF output for supplying each radiating element 316. Each RF output is routed by the BFN board 304 to an RF signal chain path (which is connected to the radiating element 316 to which the RF output is to be supplied).

[0195] The SIP module 308 may include an LDO and a voltage regulator. The LDO supplies stable DC power to the BFICs 310.

[0196] The SIP module 308 may include a plurality of power dividers for separating or integrating RF beam signals.

[0197] Each of the SIP modules 308 includes one or more BFICs (beamforming integrated circuits) 310. In certain embodiments, each of the SIP modules 308 includes six BFICs. The BFICs 310 may be space grade and may be fabricated in a rad-hard process.

[0198] The BFICs 310 implement analog, digital, and RF functions. The BFICs 310 are configured to adjust the phase and intensity for each radiating element 316 and each beam. The BFICs 310 may have N nodes. Here, N is equal to the number of simultaneous beams multiplied by the number of radiating elements in the DRA assembly 222. The BFICs 310 may be configured to perform beamforming, beam steering, and beam hopping. The BFICs 310 may include RF power splitters and combiners.

[0199] The BFICs 310 may be communicatively connected to the DRAC 224 using the BFN board 304. Thereby, the BFICs 310 can receive instructions from the DRAC. The DRAC 224 supports beam hopping performed by the BFICs 310.

[0200] The beamforming module 302 also includes one or more beam amplification modules 306 (BAMs 306). In certain embodiments, the beamforming module 302 includes four BAMs 306 per DRA assembly 222.

[0201] The BAM 306 is electrically connected to the BFN board 304 via a spring-loaded electrical connector. This electrical connection is shown by the interconnect 324 in FIG. 3. The BAM 306 receives (or transmits to the OBP 214) the RF beam signal from (or to) the OBP 214 via the electrical connector and the BFN board 304.

[0202] BAM306 is a multi-port device that integrates or separates RF signals between a single port and other ports. BAM306 may perform pre-amplification (for Tx applications) or post-amplification (for Rx applications). Pre-amplification may be performed by BAM306 before BFIC310 signal conditioning to prevent losses associated with separation and integration within the beamforming module 302 (losses will occur within the BFN board, within the SIP module, and / or within the BFIC). This may include the use of a balanced medium power amplifier to provide sufficient gain with the required linearity. Post-amplification may be performed by the BAM to amplify the RF signal input at a low level from the beamforming module. In a TxDRA implementation, post-BFIC amplification is performed in the RF signal chain path (as follows). In an RxDRA implementation, post-amplification is performed by BAM306. BAM306 may include an LNA chip to perform amplification. In some embodiments, BAM306 may implement three separate RF channels and local DC voltage regulation.

[0203] BAM306 may be attached to a heat blade 318 for a heat sink. Temperature management of BAM306 may be achieved by lowering the high heat dissipating components of BAM306 (e.g., the amplification unit) to the heat blade 318.

[0204] The DRA assembly 222 includes a thermal blade 318. The thermal blade 318 may be the thermal blade 408 of FIG. 4 or the thermal blade 528 of FIG. 5. The thermal blade 318 transfers thermal energy from a heat generation source (e.g., components of the beamforming module 302, RF signal chain path, etc.) to a heat sink. The thermal blade 318 may transfer heat passively (e.g., without requiring pumping). The thermal blade 318 is disposed within the DRA assembly 222. Thereby, the thermal blade 318 can efficiently receive and transfer heat 322 from heat generating components. This may include attaching certain components of the DRA assembly 222 (e.g., BAM 306, radiating element module 312) directly or indirectly to the thermal blade 318. Thereby, heat can be transferred from such components to the thermal blade 318 (e.g., the SIP module 308 may be in thermal contact and transfer this to an interface plate on which the thermal blade 318 is mounted). For example, the interface plate may couple the heat generated by the module 308 to all the thermal blades within the DRA.

[0205] The DRA assembly 222 includes a power conditioner (“EPC”) 320. The EPC 320 may include a plurality of physically separated EPC modules. The EPC 320 purifies and conditions power. The EPC 320 is physically connected to a power source (from which the EPC 320 receives power to be conditioned). The EPC 320 is connected to the BFN board 304 via one or more physical connectors (e.g., cables) to supply power 330 to components electrically connected to the BFN board 304. The EPC 320 supplies conditioned power to the beamforming module 302 via one or more physical connectors. The EPC 320 may interface with a spacecraft power distribution unit for bus power and a command and data handler for on / off control and analog telemetry.

[0206] The DRA assembly 222 includes a plurality of radiating element modules 312. Each of the radiating element modules 312 includes a radiating element 316 and an RF signal chain path 314 connected to the radiating element 316. The RF signal chain path 314 includes an RF path (for RF signals) and may include DC and various electrical signals. The radiating element module 312 may include a plurality of radiating elements 316 and a plurality of RF signal chain paths 314. In a particular embodiment, each of the radiating element modules 312 includes four radiating elements 316 and four RF signal chain paths 314. At this time, each of the radiating elements 316 is connected to one RF signal chain path 314 (which may also be called a "4-pack"). The number of radiating elements 316 and the number of RF signal chain paths within the radiating element module 312 are not particularly limited. For example, in another embodiment, the radiating element module 312 includes six radiating elements 316 and six RF signal chain paths 314. Alternatively, in another embodiment, the radiating element module 312 includes eight radiating elements 316 and eight RF signal chain paths 314.

[0207] The radiating element module 312 may include a front end with a radiating element 316, a polarization rotator, and a filter, and may also include a back end with RF and voltage control circuits mounted on a printed circuit board.

[0208] Each of the radiating elements 316 is a basic part of the antenna of the DRA 222 and can itself radiate or receive RF energy.

[0209] The RF signal chain path 314 includes one amplification unit for performing signal amplification. The amplification unit may be a solid state power amplifier (SSPA) or a low noise amplifier (LNA). The major part of the DRA222 gain exists within the RF signal chain path 314. The RF signal chain path 314 may include a polarization filter, a filter, an amplifier, and an isolator. The RF signal chain path 314 may implement a pre-driver before a high power amplification stage or a gain block, or after a low noise amplification stage, in order to perform sufficient amplification. The RF signal chain path 314 may be realized with an optimal RF taper by using different SSPA types and / or by controlling the operation.

[0210] The RF signal chain path 314 includes an electrical connector for connecting the radiating element module 312 to the BFN board 304 and for supporting communication between the RF signal chain path and other beamforming components. This electrical connector is shown in FIG. 3 by the interconnect 328.

[0211] As described above, certain active components of the DRA assembly 222 (e.g., the radiating element module 312 (RF signal chain path 314), the BAMs 306 or the SIP module 308) may be electrically connected to the BFN board 304 via spring-loaded electrical connectors. The electrical connectors may include spring contacts on two sides of the connector. In this case, the first side contacts the substrate and the second side contacts the BFN board 304. Using spring-loaded electrical connectors to connect the active components to the BFN board 304 is particularly useful. Such connectors have a small or zero required insertion force. Conventional or current methods for establishing electrical connections within the antenna assembly (e.g., soldering) may fail under thermal cycling conditions. For example, a DRA assembly attached to a communication satellite in orbit will be subjected to irregular thermal cycling. In a LEO application, the communication satellite orbits the Earth every 90 minutes and has various traffic loadings (and its self-heating also varies greatly). Such thermal cycling can cause significant damage to the soldered parts (especially after several years as the communication satellite orbits the Earth many times). Therefore, by using the aforementioned spring-loaded electrical connectors, the DRA assembly 222 (and certain of its components) will have greater resistance to the effects of thermal cycling to which a communication satellite in orbit is subjected. This improves the functionality and reliability of the DRA assembly and the communication satellite on which the DRA assembly is mounted.

[0212] The operation method of the Rx type DRA assembly 222 according to the embodiment will be described below. A combined radiation input signal (for example, 16 beams) is incident on the radiation elements 316 of the radiation element module 312 (for example, 4-pack). Then, the combined radiation input signal is amplified. This includes amplification by an amplification component (for example, LNA) in the RF signal chain path 318 of the radiation element 316. The main part of the signal amplification is performed in the RF signal chain path 314. Then, the signals from each radiation element 316 are routed to the SIP module 308 mounted on the BFN board 304. The SIP module 308 separates the received signal into a plurality (for example, 16) of the same signals. Each SIP module 308 includes a plurality (for example, 6) of BFICs 310. These include a phase shifter, a step attenuator, and a coherent combiner (for example, 512:1). Each partial beam at the output of the SIP module 308 is routed by the BFN board 304 to another coherent combiner. This other coherent combiner integrates various beam information and generates complete beam information based on the signals received from each radiation element 316. The BFN board 304 routes each beam from the output of the coherent combiner to the input port of the beam amplification module ("BAM"). The BAM 306 amplifies the received beam. The BAM 306 outputs the amplified beam. The output beam is routed to the input port of the OBP 214 for further processing by the OBP 214.

[0213] The operation method of the Tx type DRA assembly 222 according to the embodiment will be described below. Each beam in the output of the OBP 214 is routed to the BAM input port. The BAM 306 amplifies the received beam. The beam amplified and output from the BAM 306 is routed from the BAM 306 to the connected BFN input port. The beam signal received by the BFN is first split (e.g., into 64). The split beam is routed to the SIP module 308. The SIP module 308 further splits the received beam (e.g., into 2). Inside the SIP module 308, the signal is routed to the BFICs 310. The BFICs 310 further split the signal (e.g., 4-way split). The BFIC 310 also adjusts the phase and intensity of the signal. After the adjustment of the phase and intensity, the signals from the 16 beams are respectively coupled to the 16 radiating elements 316 (inside the BFIC 310 and inside the SIP module 308). The signal from the BFN output is sent to the designated RF signal chain path 314. The radiating element module RF signal chain path 314 amplifies the signal. The amplified signal is then supplied to the radiating element 316 for radiation. The main part of the signal amplification is performed in the RF signal chain path 314.

[0214] FIG. 4 shows a thermal management subsystem 400 for managing heat generated by a DRA assembly (e.g., the DRA assembly 222 of FIG. 2) according to an embodiment. The thermal management subsystem 400 may include components of the temperature control subsystem 216.

[0215] The thermal management subsystem 400 is configured to manage the heat generated by the active components of the DRA assembly 222 and improve the temperature efficiency of the DRA assembly 222. The thermal management subsystem 222 may passively manage the heat generated in the DRA assembly 222 (i.e., passive cooling). The thermal management subsystem 400 may passively maintain the active components within the DRA assembly 222. Thereby, the amplification unit is kept at a uniform temperature. The thermal management subsystem 400 provides a high level of natural convection and heat dissipation by using a heat spreader (e.g., heat blade) or heat sink to maximize heat transfer by radiation or convection to achieve passive cooling.

[0216] The thermal management subsystem 400 may operate for a plurality of DRA assemblies.

[0217] The DRA assembly 222 includes a plurality of heat generating units 404. The heat generating units are the active components of the DRA 222 and generate heat during operation (i.e., they are active heat sources). The heat generating unit 404 may be an electrical device such as an amplifier.

[0218] The components of the DRA assembly 222 that include the heat generating component 404 include the RF module 318, the SIP module 308, and the BAM 306. The heat generating component 404 of the RF module 318 may be within the RF signal chain path 314.

[0219] The thermal management subsystem 400 includes a heat blade 408. The heat blade 408 has one or more heat generating units 404. The heat blade 408 may operate as a heat spreader for the heat generated by the heat generating unit 404. The heat blade 408 may exclude the heat at the center of the DRA assembly 222 to the outside. The heat blade 408 may be configured to passively transfer and dissipate the heat generated by the heat generating unit 404 to one or more temperature sink elements (e.g., the following temperature sink element 412). The heat blade 408 may passively maintain the same type of heat generating units 404 so that each has a uniform temperature with respect to each other.

[0220] The heat blade 408 may also receive heat indirectly from the heat generating unit 404. For example, the heat generated by the heat generating unit of the SIP module 308 may be transmitted to the interface plate of the DRA assembly and then to the heat blade 408 (which is attached to the interface plate).

[0221] Each of the heat blades 408 includes a heat pipe. The heat pipe may be applied to transfer heat directly or indirectly. The heat pipe may be an active heat pipe. In this case, a fluid pump is provided for active cooling (actively cooling the heat blade). The heat pipe may be a passive heat pipe for passive cooling. The heat pipe may be a vibrating heat pipe (or "pulsating heat pipe"). The vibrating heat pipe may be a conventional vibrating heat pipe. The heat pipe may operate as a heat transfer device. Such a heat transfer device combines the principles of heat conduction and phase transition to efficiently transfer heat at the interface of two solids. In certain embodiments, at the hot interface of the heat pipe, a liquid in contact with the thermally conductive solid surface absorbs heat from the surface and vaporizes. The vapor then flows along the heat pipe to the cold interface, liquefies, and releases latent heat. The liquid then returns to the hot interface by capillary action, centrifugal force, or gravity. This cycle is repeated.

[0222] The heat pipe may include a sealed pipe or a tube made of a material compatible with the working fluid. In the case of a vibrating heat pipe, only a portion of the heat pipe may be filled with the working fluid. The vibrating heat pipe may be configured in a serpentine pattern. Inside this serpentine pattern, segments of freely moving liquid and vapor alternate. The vibration occurs within the working fluid, and the pipe itself does not move.

[0223] The thermal management subsystem 400 further includes a temperature sink element 412 for receiving heat from the heat blade 408. The transfer of heat from the heat blade 408 to the temperature sink element 412 occurs via a heat dissipation path 422. The temperature sink element 412 may include a heat pipe. The heat pipe of the spacecraft may function similarly to the heat blade with respect to heat conduction / exchange. The heat exchange between the heat blade 408 and the temperature sink element (e.g., the heat pipe of the spacecraft) is caused by conduction. Heat is transferred from the heat blade 408 to the temperature sink element 412 at the heat exchange interface. The heat exchange interface may be formed on the upper surface of the heat blade 408. The heat blade 408 transfers heat from the heat generating unit 404 to the temperature sink element 412 along the heat dissipation path 422. The temperature sink element 412 may be a heat pipe (e.g., the heat pipe of the spacecraft).

[0224] The temperature sink element 412 may be directly attached to the heat blade 408. For example, the temperature sink element 412 may be directly attached to the upper surface of the heat blade 408. In this case, the upper surface provides a heat exchange interface between the heat blade 408 and the temperature sink element 412.

[0225] The temperature sink element 412 may transfer the heat received from the heat blade 408 to a heat sink 416 (e.g., a radiator). The transfer of heat from the temperature sink element 412 to the heat sink 416 is effected by a heat dissipation path 424. The heat sink 416 may be a spacecraft radiator. The heat sink 416 may be configured to discard the received heat to the environment (e.g., space). The heat sink 416 may be a spacecraft panel or a flat plate radiator attached to the spacecraft. The spacecraft panel may be a structural spacecraft panel or a panel that deploys when the spacecraft is in orbit. The heat sink 416 may discard heat from its surface by infrared radiation.

[0226] Figures 5A and 5B show a perspective view 500a and a partial cross-sectional view 500b of a DRA assembly 510 according to an embodiment.

[0227] The DRA assembly 510 may be the DRA assembly 222 of FIGS. 2 and 3. The DRA assembly 510 may be a component of the DRA subsystem 110 of FIG. 1.

[0228] The DRA assembly 510 may be attached to a spacecraft (e.g., the communication satellite of FIG. 1).

[0229] The DRA assembly 510 may be used to transmit and / or receive RF radio wave signals in a predetermined frequency band.

[0230] The DRA assembly 510 includes a plurality of heat dissipation elements 512. The heat dissipation elements 512 are hidden in the shadow of the sun shield 519 (which covers the heat dissipation elements 512) in FIG. 5A. The heat dissipation elements 512 form a heat dissipation element active grid (which defines the heat dissipation surface 514 of the DRA active 510). The heat dissipation surface 514 is substantially circular. The heat dissipation elements 512 define a heat dissipation element surface 516 (which is indicated by the arrow 516 in FIG. 5B). The heat dissipation elements 512 are composed of 4-packs (that is, a group of 4 heat dissipation elements 512 belonging to the same heat dissipation element module and connected to each other). Examples of the heat dissipation element 4-packs are shown in FIGS. 8A and 8B. The heat dissipation elements 512 within each 4-pack are arranged in parallel. As described above, the number of heat dissipation elements (and RF signal chain paths) within the heat dissipation element module is not particularly limited, and the 4-pack is only an example of the heat dissipation element module. For example, as other variations, there are also 6-pack heat dissipation element modules and 8-pack heat dissipation element modules.

[0231] Each 4-pack of the heat dissipation elements 512 is attached to the RF module 520. The RF module 520 houses 4 RF signal chain paths for signal amplification. Each of the 4 RF signal chain paths within the RF module 520 is connected to one heat dissipation element 512 within the 4-pack. The RF module 520 (and the RF signal chain paths therein) is arranged in the same plane as the heat dissipation elements 512.

[0232] Each of the RF modules 520 includes an interconnect 522. The interconnect 522 may include a plurality of connectors (i.e., one or more RF connectors, one or more DC connectors, and other electrical connections). The interconnect 522 is a spring-loaded electrical connector. The connector 522 may connect the RF signal of the RF signal chain path to the BFN board, other components of the RF signal chain path, and various electrical signals. The interconnect 522 is disposed at an end of the RF module 520 opposite to the side where the radiating element 512 is attached. The four-pack of radiating elements 512, the RF module 520, and the interconnect 522 form a radiating element module. The radiating element module (including the radiating element 512, the RF module 520, and the interconnect 522) is shown in FIG. 5B. Regarding FIG. 5B, note that only one subset of the radiating element modules of the DRA assembly 510 is shown (for clarity), and additional radiating element modules are attached to the heat blades 528 within the DRA assembly 510. Generally, at least one radiating element module is attached to each heat blade 528. A given heat blade 528 may have one or more radiating element modules attached to one side of the heat blade, or may have one or more radiating element modules attached to both sides of the heat blade (opposite, i.e., facing each other). For example, the outermost or end heat blade 528 of the DRA may have radiating element modules attached to only one side.

[0233] The interconnect 522 connects the RF module 520 (and the RF signal chain path included therein) to the BFN board 524.

[0234] The BFN board 524 is disposed on and defines the board surface 526. The board surface 526 is indicated by the arrow 526 in FIG. 5B. Generally, the board plane 526 is perpendicular to the radiating element surface 516. That is, generally, the BFN board 524 and the radiating element module (including the radiating element 512 and the RF module 520) are perpendicular to each other within the DRA assembly 510.

[0235] The DRA assembly 510 includes a plurality of thermal blades 528. Each RF module 520 is attached to a thermal blade 528. Generally, the thermal blades 528 are disposed between columns of RF modules. Each thermal blade 528 has one or more RF modules 520 attached to opposite side surfaces of the thermal blade 528. The thermal blade 528 may be connected to a spacecraft bus heat pipe or a spacecraft bus thermal interface.

[0236] Generally, the thermal blades 528 are attached so as to be perpendicular to the BFN board 524 (and the interface plate 544). The thermal blades 528 define a blade plane (which is generally parallel to the radiation element plane 516 and generally perpendicular to the board plane 526).

[0237] Each thermal blade 528 may include one or more heat pipes (e.g., oscillating heat pipes) or solid metal (e.g., aluminum) thermal blades 528 to support heat conduction from the active components of the DRA assembly 550 and maintain temperature uniformity. The thermal blades 528 may have high heat conduction efficiency. The thermal blades 528 may have a passive design including non-moving components. The thermal blades 528 may be actively cooled using fluid pumps. The thermal blades 528 may conduct heat laterally from the central portion of the DRA assembly 510 (e.g., where the RF modules 520 are attached). Such heat conduction is also shown in FIG. 10.

[0238] The thermal blades 528 may provide mechanical adjustment for the DRA assembly 510 (e.g., by attaching components). The thermal blades 528 may provide structural support for the attached components (e.g., radiation element modules).

[0239] Each thermal blade 528 has a blade height 530 and a blade length 532. The blade height 530 may vary for each embodiment of the DRA assembly. The blade height 530 may be selected based on the layout of the radiation element module and the heat dissipation requirements. The blade length 532 may also vary. The blade length 532 may be selected based on the number of spacecraft pipes (e.g., the more spacecraft heat pipes, the longer the blade length required to attach the spacecraft heat pipes and provide a heat interface) attached to the thermal blade 528. The blade length 532 may be shorter in the RxDRA assembly than in the TxDRA assembly. The blade length 532 may be selected based on the heat generated by the attached components.

[0240] The DRA assembly 510 also includes a plurality of BAMs 534. In one embodiment, the number of BAMs in the DRA assembly 510 is four.

[0241] Each BAM 534 includes an interconnect. This interconnect is a spring-loaded electrical connector. The interconnect connects the BAM 534 to the BFN board 524. Generally, the BAMs 534 are arranged in the same plane 516 as the radiation element module. Thus, generally, the BAMs 534 are arranged to be perpendicular to the BFN board 524.

[0242] The BAM 534 is attached to the thermal blade 528. The BAM 534 may be attached to the thermal blade 528 in the same manner as the RF module 520. By attaching the BAMs 534 to the thermal blade 528, the heat generated by the active components of the BAM 534 can be transferred to the thermal blade 528 for heat dissipation.

[0243] Each thermal blade 528 includes an upper surface 538 and a lower surface 540.

[0244] The upper surface 538 may provide a heat exchange interface for the heat received by the heat blade 528 from the active components of the DRA assembly 510 (and may provide a DRA external heat interface for the DRA assembly 510). For example, a spacecraft heat pipe may be attached to the upper surface 538 of the heat blade 528 to receive heat from the heat blade 528 via the heat exchange interface. The number of spacecraft heat pipes attached to the heat blade 528, the heat interface material, and the number of attachment interfaces may vary. The size of the upper surface 538 may be set to an extent sufficient to provide heat conduction capable of compensating for the temperature difference. The upper surface 538 may include a high-efficiency temperature filter.

[0245] The lower surface 540 may be used to attach the heat blade 528 (and as a result, components attached to the heat blade 528, such as the radiation element module and BAMs 536, etc.) to the upper surface 542 of the spacecraft interface plate 544. The spacecraft interface plate 544 is attached to the spacecraft bus panel. Heat may be transferred from the interface plate 544 (heat from the SIP) to the heat blade 528 via the interface 540. The interface plate may couple the heat from the SIP module to all the heat blades 528 within the DRA 510.

[0246] The DRA assembly 510 includes cross straps 546. The cross straps 546 may achieve further structural adjustment and arrangement of the DRA assembly 510 by fixing the heat blades 528 to each other. The cross straps 546 are attached to the heat blades 528 at the upper surface 538. The cross straps 546 are included on each face of the radiation element active grid.

[0247] The DRA assembly 510 may include one or more heat shields. The heat shields may be used to cover the exposed RF modules 520 (e.g., those in front of the frontmost blade or behind the rearmost blade). The heat shields are attached to the heat blades 528.

[0248] The DRA assembly includes a plurality of SIP modules (not shown). The SIP modules are attached to opposite faces of the BFN board 524 (see, for example, FIG. 6). The SIP modules may be configured in a double stack (two stacks) on the BFN board. The SIP modules may be attached to the BFN board 524 such that the plane defined by the SIP module is substantially parallel to the plane defined by the BFN board 526 (i.e., plane 526). The SIP module attached to the upper surface of the BFN board 524 may be thermally coupled to the interface plate 544 to transfer the heat generated by the heat generating unit of the SIP module to the heat blade 528 for heat dissipation.

[0249] The DRA assembly 510 includes a BFN cover 552. The BFN cover 552 is attached to the lower surface 554 of the interface plate 544. The BFN cover 552 houses the BFN board 524 and the components attached thereto (e.g., SIP modules).

[0250] The DRA assembly 510 may include one or more EPC modules 556. The EPC module 556 is attached to a dedicated EPC heat blade 558. The EPC heat blade 558 is structurally and functionally similar to the heat blade 528. The EPC heat blade 558 includes an upper surface 560. The upper surface 560 provides a heat exchange interface for the EPC heat blade 558. The cross strap 546 is also attached to the upper surface 560 of the EPC heat blade 558.

[0251] By attaching the EPC module 556 to the dedicated heat blade 558, the advantage of shortening the cable length can be obtained. The EPC module 556 may be attached to the EPC heat blade 558 such that a wide heat exchange area is obtained between the EPC module board and the heat blade 558.

[0252] The EPC hot blade 558 is attached to the interface plate 544 (similar to the hot blade 528). The EPC module 556 extends through a hole within the interface plate 544. Thereby, the connector ports of the EPC module 556 appear outside the interface plate 544.

[0253] The connector 562 is connected to the connector port of the EPC module 556 at its first end and to the connector port of the BFN board 524 at its second end. The connector 562 extends through a hole within the BFN cover 552 to connect to the BFN board 524.

[0254] The DRA assembly 510 provides various advantages. The DRA assembly 510 is designed to be modularly scalable, high-performance, and easy to integrate. The DRA assembly 510 uses a single board for the beamforming network. A single beamforming network can transmit all RF and electrical signals as well as DC power to the RF signal chain of the DRA 510. By using a single board for the beamforming network, various advantages can be obtained, such as cost reduction, weight reduction, reduction in the number of interconnections, reduction in the number of components, etc. With the DRA assembly 510, all SIP modules 550 and BFN boards 524 can be arranged on substantially the same plane (e.g., plane 526). Advantageously, by taking this arrangement, the interconnection between the BFN board and the radiating element module can be simplified.

[0255] Figure 6 shows a top perspective view 600 of the BFN assembly 610 of the DRA assembly 510 of FIG. 5 according to an embodiment.

[0256] The BFN assembly 610 is a single-board surface mount.

[0257] The BFN assembly 610 includes the BFN board 524. The BFN board 524 includes an upper surface 612 and a lower surface 614.

[0258] The BFN assembly 610 includes a plurality of SIP modules 550. The SIP modules 550 may be mounted in one plane. By mounting the SIP modules in one plane (i.e., planar mounting to the BFN board), various problems that occur when the SIP is mounted on multiple boards (and thus multiple planes) can be solved. For example, when the SIP modules are mounted on multiple boards (and thus multiple planes), the interconnections between them become complex, the mass increases, the cost increases, and the RF performance degrades.

[0259] The SIP modules include top-mounted SIP modules 616 (which are mounted on the top surface of the BFN board 524) and bottom-mounted SIP modules 618 (which are mounted on the bottom surface of the BFN board 524). The top-mounted SIP modules 616 and the bottom-mounted SIP modules 618 each define a plane that is substantially parallel to the plane defined by the BFN board 524 (e.g., plane 526 in FIG. 5B). The number of SIP modules within the BFN assembly 610 may vary depending on the application.

[0260] The SIP module 550 is attached to the BFN board 524 in a "double stack" or "back-to-back" configuration. In this case, each double stack includes a top-mounted SIP module 616 and a bottom-mounted SIP module 618. Generally, the top-mounted SIP module 616 and the bottom-mounted SIP module 618 face the same direction towards the BFN board 524. As a result, the bottom surface of the top-mounted SIP module 616 is aligned with the bottom surface of the bottom-mounted SIP module 618. The top-mounted SIP module 616 may be connected to the bottom-mounted SIP module 618 using a plurality of fasteners. These fasteners also function as heat conductors to transfer heat from the bottom-mounted SIP module 618 to the top-mounted SIP module 616. When the top-mounted SIP module 616 is disposed within the DRA 510, it may contact an interface plate (e.g., the interface plate 544 of FIG. 5). This supports heat conduction from the top-mounted SIP module 616 to the interface plate (this heat may be generated in the top-mounted SIP module 616 or may be generated in the bottom-mounted SIP module 61 and transferred to the top-mounted SIP module 616). The heat may be transferred to a heat blade (e.g., the heat blade 528 of FIG. 5) for heat dissipation.

[0261] The upper surface 612 of the BFN board 524 includes a plurality of radiating element module electrical ports. These radiating element module electrical ports are disposed in the region 626. The radiating element module electrical ports are configured to receive the electrical connectors of the radiating element modules to support the electrical connection between the RF signal chain path and the BFN assembly 610. The BFN board 524 includes radiating element module electrical ports for each radiating element module within the array. The radiating element module electrical ports may include a plurality of ports (e.g., RF ports for each RF signal chain path within the radiating element module, 3 / 4 DC ports, and a plurality of digital / CMD / TM ports, etc.).

[0262] Figure 7 shows an isolated SIP module 700 according to an embodiment. The SIP module 700 may be the SIP module 308 of FIG. 3 or the SIP module 550 of FIG. 6.

[0263] The SIP module 700 may be attached to the upper or lower surface of a BFN board (e.g., BFN board 524). The SIP module 700 may be disposed within a DRA assembly in a double-stack configuration.

[0264] The SIP module 700 includes a top cover 706. The top cover 706 may be made of aluminum. When assembled to the DRA assembly, the top cover 706 may contact an interface plate (e.g., interface plate 544 of FIG. 5) and may support heat conduction from the SIP module 700 (or another SIP module).

[0265] The SIP module 700 includes a substrate layer 708. The substrate layer 708 may be an LTCC substrate. One or more BFICs may be attached to the substrate layer 708. In a particular embodiment, six BFICs are attached to the substrate layer 708.

[0266] The SIP module 700 includes a bottom cover 704. When the SIP module is attached to the BFN board, a thermal gasket may be included between the SIP module (bottom cover 704) and the BFN board.

[0267] The SIP module 700 includes an interposer 702 between the SIP-BFN boards. The interposer 702 may be an electrical interface routing between one socket or connection and another socket or connection. The interposer 702 may be a spring-loaded electrical connection to the BFN board. The spring-loaded electrical connection provides for reworkability of the BFN assembly and DRA. The interposer 702 may receive signals generated by the BFICs of the SIP module 700 and route the signals to the BFN board for further processing.

[0268] The SIP module 700 also includes mounting holes 710. The mounting holes 710 are configured to receive a fastener. The fastener may be used to connect the SIP module 700 to the BFN board. In the case of a double-stack configuration, the fastener may be used to connect the SIP module 700 to a second SIP module.

[0269] Figures 8A and 8B show a radiating element (「RE」) module 800 according to an embodiment. The radiating element module 800 may be used in the DRA assembly 510 of FIG. 5. The illustrated radiating element module 800 has four radiating elements (and four RF signal chain paths). However, in another embodiment, the radiating element module 800 may have fewer (or more) radiating elements and RF signal chain paths.

[0270] The RE module 800 includes an RF radiation element 4-pack 802 having four RF radiation elements 804 arranged in a column. The radiation elements 804 may be 3D printed. Generally, each of the radiation elements 804 has a hexagonal cross-section 816. In another embodiment, the cross-section of the radiation element 804 may be square or circular. Adjacent radiation elements 804 have an element spacing. This element spacing is defined by the linear distance between the respective geometric centers in the cross-section of adjacent radiation elements 804 (in this case, the cross-section is hexagonal). Generally, the element spacing within the radiation element array is geometrically maintained between the outer radiation element 804 of the 4-pack 802 and the outer radiation element of an adjacent radiation element 4-pack.

[0271] The RE module 800 includes an RF module 806. The RF radiation element 4-pack 802 is connected to the RF module via a connection. The connection includes an electrical and mechanical interface between the radiation element and the RF signal chain path (i.e., between the radiation element component and the RF module). This interface provides RF connectivity and adjustment characteristics. The connection supports the alignment of the RF module 806 and the radiation element 804. The connection positions, adheres, and seals the RF module 806 and the RF radiation element 4-pack 802. Thereby, the radiation element module 800 is created.

[0272] The RF module 806 houses various active components. The RF module 806 includes one amplification path for each radiation element 804 to amplify the RF signal.

[0273] The RF module 806 may include mounting holes for receiving fasteners (e.g., screws, etc.) for connecting the RF module (and thus the RE module (radiation element module) 800) to a heat sink. The mounting holes may be common mounting holes for mounting the RE module 800 back-to-back to the heat sink throughout the DRA. The mounting holes may be used to press the RE module 800 against a thermal interface (e.g., a heat sink) to obtain good conductivity.

[0274] The RE module 800 includes a spring-loaded connector 812 for connection to the BFN board of the DRA assembly. The spring-loaded connector 812 provides an RF and DC interface. The spring-loaded connector 812 may provide tolerances regarding translation and rotation.

[0275] The 4-pack RE module 800 may facilitate the assembly of the DRA assembly and allow for quick customization and application according to the requirements of the antenna (e.g., different numbers of radiating elements).

[0276] FIG. 9 shows a partial cross-sectional view of a radiating element module 900 according to an embodiment. The portion 900 shown in cross-section corresponds to the RF module of the radiating element module 900. Advantageously, the radiating element module 900 is low-cost and highly productive. The radiating element module 900 may be connected to a BFN board (e.g., the BFN board 524 of FIG. 5).

[0277] The radiating element module 900 has a radiating end 914 and an RF chain end 916. These are arranged at opposite ends along the longitudinal direction of the radiating element module 900.

[0278] Starting from the radiating end 914, the radiating element module 900 includes a 4-pack 902 of radiating elements 904a, 904b, 904c, 904d (collectively referred to as radiating elements 904). The radiating elements 904 are arranged in a row (or linearly).

[0279] Each radiating element 904 of the 4-pack 902 may be connected to a polarization filter, a filter, an amplifier, and / or an isolator. The filter may be part of the radiating element 904.

[0280] The radiation element module 900 includes an RF module 908. The RF module 908 is connected to the radiation element 904 at a first end near the radiation end and is connected to an electrically spring-loaded connector 912 at a second end near the RF signal chain path end 916. The electrical connector 912 connects the RF module 908 (and thus the radiation element module 900) to the BFN board of the DRA assembly (e.g., the BFN board 524 of the DRA assembly 510 in FIG. 5). The RF module 908 (e.g., its housing) may be part of the integrated radiation element 904 (i.e., the RF module 908 and the individual radiation element 904).

[0281] The RF module 908 includes a circuit board 918 on which various electrical components are mounted. The circuit board 918 may be a flexible organic board. The electrical components include a chipset. The chipset may include a high-power amplifier (HPA) or a low-noise amplifier (LNA). The chipset also includes an RF tuning chip that compensates for phase and intensity with respect to temperature. The RF tuning chip may be used for pre / post-amplification. The RF tuning chip may be optimized for low-power compensation and dynamic control (intensity / phase). Thereby, the radiation element module 900 can closely follow temperature.

[0282] The RF module 908 includes an RF signal chain path 910 (or signal amplification path) for each radiation element 904 of the 4-pack 902 (thus, the number of RF signal chain paths is equal to the number of radiation elements in the radiation element module). The RF signal chain paths 910 may be arranged adjacent to each other in parallel. In certain embodiments, the RF module 908 houses four individual RF chains.

[0283] Each of the RF chains is connected to a dedicated radiation element. For example, in FIG. 9, the RF signal chain path 910 is connected to the radiation element 904b.

[0284] The RF module 908 may include an active RF circuit - radiator element interface, which is an interface between the active RF circuit and the radiator element 904. The active RF circuit - radiator element interface may be designed with the goals of low loss, broadband RF performance, and ease of productization.

[0285] The RF signal chain path of the RF module 908 may be included within the collective radiator element bottom surface (also referred to as the collective element bottom surface) of the radiator element module 900. The collective radiator element bottom surface is defined by the radiator elements 904 (i.e., included in the portion defined by the collective bottom surface). Each of the radiator elements 904 defines an individual element bottom surface (or volume). Such bottom surfaces are defined by the cross - section of the radiator element 904 when viewed from the radiation end 914. In this case, the cross - section of the radiator element 904 is a hexagon extending from the radiation end 914 towards the RF chain end 916. The collective (or combined) element bottom surface includes the combination of the individual bottom surfaces of each radiator element 904. Generally, the RF signal chain paths 910 may be arranged parallel to each other and within their respective radiator element bottom surfaces. By arranging the RF signal chain paths 910 such that they are all included within the collective radiator element bottom surface, the spacing between elements (i.e., the spacing between adjacent radiator elements) can be narrowed (e.g., made relatively small).

[0286] The RF signal chain paths 910 can also be completely included within their respective elements (see Figure 9). Furthermore, each RF signal chain path 910 can be completely included within its respective element bottom surface, and all the RF signal chain paths can be accommodated within the collective radiator element bottom surface of the radiator element module 900.

[0287] The 4 - pack radiator element module 900 accommodates each RF signal chain path.

[0288] In the Tx implementation, each RF signal chain path 910 may amplify and transmit the beamforming composite signal generated at the OBP and obtained through a plurality (e.g., 16) of beam inputs. In Tx, a radiation power taper may be used to maximize beam performance.

[0289] In the Rx implementation, each RF signal chain path 910 may receive and amplify the weak user composite signal before separation within the beamforming module. In Rx, the received power taper may be used to maximize beam performance.

[0290] The RF signal chain path 910 may include various components (e.g., filters, isolators, RF components, and DC components, etc.). The isolator may perform impedance matching between the amplification unit (e.g., HPA, LNA) and the radiating element 904. The RF signal chain path 910 also includes an amplifier. This amplifier may be arranged before or after the filter and the isolator (e.g., before Tx, after Rx).

[0291] The RF module 908 may be configured such that the heat dissipation device (e.g., amplifier) of the RF module 908 dissipates heat along the heat path to the DRA heat sink (e.g., through the heat blade to the spacecraft heat pipe). This design improves the thermal efficiency.

[0292] FIG. 10 shows a cross-sectional view of a DRA assembly 1000 according to an embodiment, showing the heat dissipation path of the heat generating components of the DRA assembly. Similar to FIG. 5B, FIG. 10 shows only a subset of the radiating element modules (which are attached to the heat blades within the assembled DRA). There are additional radiating element modules not shown within the assembled DRA. At least one radiating element module may be attached to each heat blade.

[0293] The thermal control and management of the heat dissipation path of the active components of the DRA assembly 1000 may be performed by the thermal management subsystem 400 of FIG. 4. The thermal management performed in the DRA assembly 1000 is passive.

[0294] As described above, the DRA assembly 1000 includes heat dissipating components. That is, the DRA assembly 1000 includes heat generating components that generate and dissipate heat during the operation of the DRA assembly 1000. Such components are the active components of the DRA assembly 1020. And such components generate heat that requires management and control in order to maintain the efficiency of the DRA assembly 1000 and keep such components within an acceptable temperature range.

[0295] The heat dissipating components of the DRA assembly 1000 include RF modules, SIP modules, and BAMs. The RF module is shown by the RF module 1004 in FIG. 10. The BAMs are not shown in FIG. 10, but are attached to the BFN board 1036 (similar to FIG. 6). In some cases, the RF module 1004, the SIP module, and the BAMs 1012 are the main heat dissipating components of the DRA assembly 1000. Therefore, in this case, the management of the heat (generated by these components) by the DRA assembly 1000 is important for optimizing the function of the DRA 1000.

[0296] Generally, the heat from the heat generating components of the RF module 1004, the BAMs 1012, and the SIP module is transmitted to the heat blade 1016. The heat blade 1016 is attached to the interface plate 1004.

[0297] The DRA assembly 1000 is configured such that the RF module 1000 (particularly, its heat generating components) transfers heat from the heat generating components to the heat blade 1016 (to which the RF module 1004 is attached here). The heat is transmitted along the RF module heat dissipation path 1020.

[0298] The RF module 1004 includes a heat-dissipating component (i.e., a heat-generating component or a heat-generating unit) such as an amplifier. The amplifier may be a solid-state power amplifier (SSPA) (e.g., in a TxDRA assembly) or a low-noise amplifier (LNA) (e.g., in an RxDRA assembly). The RF module may be an SSPA 4-pack module or an LNA 4-pack module.

[0299] The DRA assembly 1000 has a low-thermal-resistance path from the amplifier to the heat blade 1016. The RF module 1004 may include a heat spreader located near a high-power amplifier (e.g., approximately in the middle of the RF signal chain path). The RF module 1004 may include a thermal gasket interface between the RF module 1004 and the heat blade 1016 to transfer heat from the heat-generating component of the RF module 1004 to the heat blade 1016. The thermal gasket may be a high-efficiency thermal gasket. Here, high-efficiency means that the thermal gasket effectively transfers heat from one side of the interface to the other, thus minimizing the temperature difference between the two. The thermal gasket may be applied (or selected) to minimize the temperature difference between the RF module 1004 and the heat blade 1016.

[0300] The heat generated by the SIP module is transferred or dissipated along the heat dissipation path 1024.

[0301] The SIP module is attached to a BFN board 1036 (which is attached to an interface plate 1040). The SIP module may include a top-mounted SIP module and a bottom-mounted SIP module. The top-mounted SIP module is attached to the top surface of the BFN board 1036. The bottom-mounted SIP module is attached to the bottom surface of the BFN board 1036. The top-mounted SIP module and the bottom-mounted SIP module may be attached to the BFN board 1036 back-to-back.

[0302] The SIP module (top and bottom mounted SIP module) may include a thermal gasket interface to the BFN board 1036.

[0303] The top mounted SIP module may have a thermal gasket interface to the interface plate 104.

[0304] The SIP module may be configured to include a thermal interface material and an aluminum lid.

[0305] When the SIP modules are double stacked, two thermal paths may be used to transfer heat from the bottom mounted SIP module to the top mounted SIP module (which contacts the interface plate 1040). The first thermal path uses a thermal gasket between each SIP (e.g., lid 704 of FIG. 7) and the BFN board 1036. The second thermal path uses heat conduction by a metal screw connecting the top SIP module and the bottom mounted SIP module.

[0306] The heat generated by the SIP module is transferred to the heat blade 1016.

[0307] The heat generated by the BAMs is transferred along the heat dissipation path 1028 and dissipated.

[0308] BAM 1012 includes heat generating components. The heat generating components include one or more amplifiers. The heat generating components (e.g., amplifiers) within BAM 1012 may have a direct thermal path (e.g., path 1028) to the heat blade 1016.

[0309] Each of the heat blades 1016 includes an upper surface that provides a heat exchange interface. The heat received by the heat blade 1016 from the RF module 1004, the SIP module, and the BAMs 1012 via the heat dissipation paths 1020, 1024, 1028 is dissipated at the upper surface 1018 of the heat blade 1016 along the heat dissipation path 1032.

[0310] A heat pipe (e.g., a spacecraft heat pipe) may be attached to the upper surface 1018 to receive heat from the upper surface 1018 of the hot blade 1016 and dissipate this heat along the heat dissipation path 1032 or further transfer it to a spacecraft radiator.

[0311] Additional heat generating components may be attached to the BFN board 1036. For example, an FPGA (not shown) may be attached to the BFN board 1036. The FPGA may be a high heat dissipation component. The FPGA may be intentionally attached to the upper surface of the BFN board 1036 to have a direct heat path to the interface plate 1040 through the heat filler and the pedestal. Heat generated by the FPGA (or other components) may then be transferred through the interface plate 1040 to the hot blade 1016 (which is attached to the interface plate 1040). Subsequently, this heat may be dissipated by the hot blade 1016 along the heat dissipation path 1032.

[0312] FIG. 11 shows an upper perspective view 1100 of a DRA assembly 1102 with a heat pipe attached, according to an embodiment. The DRA assembly may be the DRA assembly 510 of FIG. 5. The DRA assembly 1102 may employ the heat management and heat conduction of FIG. 10.

[0313] The DRA assembly 1102 includes a plurality of radiating elements 1104 (which form a radiating element active lattice). Each of the radiating elements 1104 of the radiating element active lattice is connected to an RF module (not shown) (e.g., the RF module 520 of FIG. 5). For example, each RF module may be connected to four radiating elements 1104.

[0314] The DRA assembly 1102 includes other active heat generating components (e.g., BAMs and SIP modules), but these are not shown in FIG. 11.

[0315] The DRA assembly 1102 includes thermal blades 1108 (each of which is attached to an interface plate 1112). The interface plate 1112 is attached to a spacecraft panel for attaching the DRA assembly to the spacecraft.

[0316] Each thermal blade 1108 includes an upper surface (such as the upper surface 538 of the thermal blade 528 in FIG. 5). This upper surface provides a heat exchange interface for the heat generated by heat generating components (such as RF modules) and passively transferred to the thermal blade 1108.

[0317] The DRA assembly further includes an EPC module 1120 (which is composed of five physically separated modules). The EPC module 1124 is attached to a dedicated EPC blade 1124. The dedicated EPC blade 1124 includes an upper surface. This upper surface functions as a heat exchange interface for the heat generated by the heat generating components of the EPC module 1120 and passively transferred to the dedicated EPC blade 1124.

[0318] A plurality of spacecraft heat pipes 1128 are attached to the upper surfaces of the thermal blades 1108 and the upper surface of the dedicated EPC thermal blade 1124. Note that the upper surface of the thermal blade 1108 is hidden in the shadow of the spacecraft heat pipe 1128 and is not shown in FIG. 11. Heat is transferred from the upper surfaces 1116, 1125 of the thermal blade 1108 to the spacecraft heat pipe 1128. FIG. 11 shows that there are 12 heat pipes (6 in groups of 3 on each side of the radiating element active grid), but the number of heat pipes 1128 is not particularly limited to this. For example, in another embodiment, 2, 3 or 5 heat pipes 1128 may be attached to both sides of the radiating element active grid. The number of heat pipes 1128 may depend on the heat interface requirements and the structure of the spacecraft.

[0319] The heat received by the spacecraft heat pipe 1128 is transferred along the heat dissipation path 1132. Further, the spacecraft heat pipe 1128 may transfer the heat to a heat sink (e.g., radiator) along the heat dissipation path.

[0320] FIG. 12 shows a method 1200 for manufacturing a DRA assembly according to an embodiment. The method 1200 may be used, for example, to manufacture the DRA assembly 500 of FIG. 5.

[0321] At 1202, a plurality of radiation element modules are attached to the heat blade. In a particular embodiment, the radiation element modules are attached to opposite sides of the heat blade (i.e., rows of radiation element modules on each side of the heat blade). When the assembled heat blade is formed, all the radiation element modules are attached.

[0322] At 1204, the BFN assembly is attached to the interface plate 2108. The BFN assembly may be the BFN assembly 610 of FIG. 6. The BFN module includes a plurality of SIP modules attached to a BFN board.

[0323] At 1206, the coaxial bulkhead is attached to the BFN cover. The bottom cover is attached to the BFN cover. The BFN cover is attached to the interface plate.

[0324] At 1208, the assembled heat blade is attached to the interface plate by attaching the bottom surface of the heat blade and connected to the BFN assembly (in particular, the radiation element modules are connected to the BFN board of the BFN assembly via spring-loaded electrical connectors).

[0325] The BFN assembly is disposed in the same plane as the interface plate under the interface plate and is housed within the BFN cover.

[0326] At 1210, a cross strap and a radiation shield are attached to the thermal blade. In particular, the cross strap is attached to the upper surface of the thermal blade. The radiation shields are respectively attached to the front surface of the foremost thermal blade and the rear surface of the rearmost thermal blade.

[0327] At 1012, the EPC module is attached to a dedicated EPC thermal blade. The assembled EPC and thermal blade are then attached to an interface plate.

[0328] Figures 13A and 13B respectively show a perspective view 1300a and a top view 13b of a communication satellite 1310 according to an embodiment. The communication satellite 1310 may be the communication satellite 110 of FIG. 1. The communication satellite 1310 may be a LEO satellite.

[0329] The communication satellite 1310 includes a spacecraft 1312. The communication satellite 1310 further includes DRA assemblies 1314a, 1314b, 1314c, and 1314d (collectively referred to as DRA assembly 1314). The DRA assembly 1314 may be, for example, the DRA assembly 510 of FIG. 5. In this particular case, the DRA assemblies 1314a, 1314b are Tx antennas, and the DRA assemblies 1314c, 1314d are Rx antennas.

[0330] The DRA assembly 1314 is attached to the upper surface 1316 of the spacecraft 1312. In particular, the upper surface 1316 includes a spacecraft panel. The DRA assembly 1314 is attached to the spacecraft panel via, for example, an interface plate (e.g., the interface plate 544 of FIG. 5). The DRA assembly may be attached to an underpanel.

[0331] Communication satellite 1310 further includes a spacecraft heat pipe 1318. The spacecraft heat pipe 1318 is attached to the upper surface of the heat blade 1320 of the DRA assembly 1314. The spacecraft heat pipe 1318 is attached and arranged substantially perpendicular to the configuration of the heat blade 1320. The spacecraft heat pipe 1318 is attached to each surface of the radiation element active grid on the upper surface of the heat blade 1320. For example, in the communication satellite 1310, six heat pipes 1318 are attached to each surface of the radiation element active grids of the DRA assemblies 1314a and 1314b. And three heat pipes 1318 are attached to each surface of the radiation element active grids of the DRA assemblies 1314c and 1314d. The spacecraft heat pipe 1318 may include a flat bottom surface facing the heat blade. The spacecraft heat pipe 1318 is connected to a spacecraft panel (for example, the side of the spacecraft panel 1322).

[0332] The spacecraft heat pipe 1318 is fixed to the 1322 side (for example, that spacecraft panel) of the spacecraft 1312 and extends downward.

[0333] Figures 14 to 18 show a direct radiation array (DRA) assembly 10 according to an embodiment. This is particularly used for an antenna or the like on board or for a spacecraft (not shown but indicated by its mounting panel 12) for transmitting and / or receiving RF (radio frequency) radio wave signals in a predetermined frequency band.

[0334] The DRA assembly 10 includes a plurality of radiation elements 22 that define a radiation surface 20 (shown by a dashed line in FIG. 14). Each radiation element 22 forms a part of the radiation surface and defines an element contour bottom surface 24 (see FIGS. 17 and 18). The element bottom surfaces 24 are arranged side by side and contact the corresponding element bottom surfaces 24 of adjacent radiation elements 22. Although not necessary, as a result, adjacent radiation elements 22 contact each other.

[0335] The DRA assembly 10 also includes, for each radiating element 22, a signal RF signal chain path 30 (shown schematically in FIG. 17 by a dotted line along different RF signal chain paths 30). Preferably, each RF signal chain path 30 (typically also called a signal amplification path) is at least partially disposed within the element volume 26 (which extends in a direction substantially perpendicular to the element bottom surface 24 of the corresponding radiating element 22 and below the element bottom surface 24 in a direction opposite to the radiation of the signal) (see FIG. 17). The signal amplification path 30 includes, among many antenna amplification path components, at least one heat generating unit 32 (for example, an amplification unit for amplifying an antenna signal transmitted (or received) to the corresponding radiating component 22).

[0336] The DRA assembly 10 also includes a plurality of temperature sink elements 30, 40. Each temperature sink element extends within at least one element volume and is connected to a heat radiator of a spacecraft / satellite, etc. (for example, a spacecraft mounting panel 12 for transferring heat through a heat conduction path and / or a local heat dissipation surface mirror 42 (or heat blade)). Each amplification unit 32 is attached to one of the temperature sink elements 40 to transfer the generated heat. The temperature sink elements 40 are applied to immediately and passively transfer or dissipate the heat received from different amplifiers 32 to the heat radiators 12, 42 and to keep the amplification units 32 at approximately the same temperature relative to each other.

[0337] Each temperature sink element 40 has a generally flat blade shape. This defines a blade surface 44 (shown by a dashed line in FIG. 14) and extends below the radiation surface 20 in a direction substantially perpendicular to the radiation surface 20 within the blade surface. Since the radiating element 22 and its signal amplification path 30 are arranged differently from the temperature sink element 40, each temperature sink element 40 also functions as a structural support for the corresponding radiating element 22 and the signal amplification path 30 attached thereto, and further functions as a mechanical adjustment device for the DRA assembly 10. To improve the structural behavior of the DRA assembly 10, additional structural supports 46 (see FIG. 14) are typically used to fix different temperature sink elements 40 (preferably those adjacent to the radiating element 22) to each other.

[0338] Typically, each temperature sink element 40 is a conventional oscillating heat pipe (OHP) or pulsating heat pipe (PHP).

[0339] As shown in FIG. 18, each signal amplification path 30 is oriented in a direction perpendicular to the respective radiation element 20. In such a case, the electrical connection can be made using any type of connection / connector 34 (including 90-degree or other RF connections).

[0340] As best shown in FIG. 18, the respective geometric centers 24' of the element bottoms 24 of two adjacent radiation elements 22 are arranged with an element-to-element distance 28 therebetween. The element-to-element distance 28 may be based on the RF frequency and the required DRA scan range.

[0341] Each element bottom 24 may also be in a substantially symmetric shape, such as a hexagon (shown in FIGS. 14 - 18).

[0342] As shown in FIG. 16, typically the radiation elements 22 may be arranged adjacent to each other in a plurality of columns 23. The amplifiers 32 of the radiation elements 22 of two adjacent columns 23 are typically attached to one opposing surface of the temperature sink element 40. The temperature sink element 40 extends between two adjacent columns 23.

[0343] As shown in FIGS. 16 to 18, the radiation elements 22 (including their respective signal amplification paths 30) are typically arranged in groups (or sets of modules). This is to facilitate assembly and to expedite the customization or application of the DRA assembly 10 in response to corresponding antenna requirements, which may call for different numbers of radiation elements 22. Groups or modules with different numbers (1, 2, 3, 4, etc.) and shapes (linear, triangular, square, etc.) are also within the scope of the present disclosure.

[0344] It is a general object of the present disclosure to provide an improved direct radiation array (DRA) assembly for solving various problems of conventional or current DRA antennas.

[0345] One advantage of the present disclosure is that the DRA assembly is small and lightweight while being applicable particularly to high-power antennas.

[0346] Another advantage of the present disclosure is that the DRA assembly can efficiently dissipate heat generated in the amplification units of each signal amplification path of different radiation elements to a heat sink via a plurality of temperature sink elements (e.g., a plurality of heat pipes, etc.). Such elements also function as structural elements for supporting different electrical components of the antenna.

[0347] A further advantage of the present disclosure is that the DRA assembly has a plurality of radiation elements. These radiation elements define the radiation surface of the DRA assembly. Each radiation element also has a signal RF signal chain path (e.g., a signal amplification path). Advantageously, these signal RF signal chain paths are at least partially disposed inside the element volume. The element volume extends in a direction substantially perpendicular to the element bottom surface of the radiation element and in the opposite direction to the radiation surface. It is obvious that, depending on design constraints, etc., a part (or only a part) of the signal RF signal chain path protrudes outside the element volume. Typically, the signal amplification path is electrically connected to the radiation element (patch) via an RF connection / connector.

[0348] A further advantage of the present disclosure is that the DRA assembly has a plurality of radiation elements arranged in a plurality of columns adjacent to each other. Further, the signal amplifiers of each signal amplification path of all the radiation elements in the same column are typically attached to the same temperature sink element. Preferably, all the signal amplifiers of two adjacent columns are attached between the same temperature sink elements.

[0349] A further advantage of the present disclosure is that the DRA assembly includes a plurality of temperature sink elements that are used to transfer heat generated by different signal amplifiers to the heat radiator immediately and passively (or automatically, i.e., contrary to actively using some electrical components and / or electrical controls). Further, the DRA assembly passively maintains the temperatures of all the amplifiers substantially uniformly with respect to each other (particularly between the radiation elements arranged around the radiation surface and the radiation element arranged at the center of the radiation surface). Thereby, the RF performance of the DRA antenna is significantly improved. Due to the temperature sink elements, all heat sources (including the amplifiers) can have a substantially identical direct heat path (identical temperature gradient) to the heat sink (such as a heat radiator). Further, the temperature sink elements typically also function as structural elements for fixing the DRA assembly. Further, the temperature sink elements can also be used to mechanically adjust different parts of the DRA antenna relative to each other.

[0350] A further advantage of the present disclosure is that the temperature sink elements of the DRA assembly are configured to be substantially planar and extend below the DRA radiation surface substantially perpendicular to the DRA radiation surface in the direction of the blade surface.

[0351] A further advantage of the present disclosure is that each of the radiation surfaces of the DRA antenna has the geometric center of the bottom surfaces of two adjacent radiation elements (with an element-to-element distance therebetween, arranged with an element-to-element distance from each other). The element-to-element distance may be based on the RF frequency and the required DRA scan range.

[0352] A further advantage of the present disclosure is that since the functions of the DRA assembly are concentrated within the bottom surfaces of the radiation elements, the design is modular. Therefore, by increasing or decreasing the number of radiation elements, the overall performance (electrical and mechanical) can be quickly adapted to the requirements.

[0353] A further advantage of the present disclosure is that the DRA assembly can be miniaturized and its weight can be reduced. According to this embodiment, the weight can be reduced by 40% compared to a conventional DRA assembly having the same performance.

[0354] In certain aspects of the present disclosure, a direct radiating array (DRA assembly) is provided for use in a spacecraft antenna to transmit and / or receive RF radio frequency signals in a predetermined frequency band. The assembly includes a plurality of radiating elements that define a radiating surface of the DRA assembly, an RF signal chain path for each radiating element, and a plurality of temperature sink elements. Each of the radiating elements forms a radiating surface and defines an element bottom surface that is disposed side-by-side with the element bottom surfaces of adjacent radiating elements. The RF signal chain path is disposed at least partially within the element volume of the corresponding radiating element, which extends in a direction opposite to the radiating direction in a direction substantially perpendicular to the element bottom surface. The RF signal chain path includes at least one heat generating unit. Each of the temperature sink elements extends within at least one element volume and is connected to a heat radiator.

[0355] In certain embodiments, each temperature sink element may be in a substantially flat shape that defines a component surface. This blade surface may extend below the radiating surface in a direction substantially perpendicular to the radiating surface. At least one heat generating unit is attached to one of the plurality of temperature sink elements to transfer the generated heat. The plurality of temperature sink elements immediately and passively transfer the generated heat to the heat radiator and keep the heat generating unit at a substantially uniform temperature relative to other heat generating units.

[0356] Advantageously, each single amplification path extends in a direction substantially perpendicular to each of the plurality of radiating elements.

[0357] In certain embodiments, the geometric centers of each of the adjacent two radiating element bottom surfaces of the plurality of radiating elements are spaced apart by an element spacing. The element spacing may be based on the RF frequency and the required scan range of the DRA.

[0358] In certain embodiments, each element bottom surface is substantially symmetric, preferably hexagonal.

[0359] In certain embodiments, each temperature sink element is a vibrating heat pipe.

[0360] In one embodiment, a plurality of radiating elements are arranged in a plurality of rows adjacent to each other. At least one of the heat generating units corresponding to two adjacent radiating elements of the plurality of rows is attached to opposite sides of each of the temperature sink elements. The temperature sink elements extend between the two adjacent rows described above.

[0361] In one embodiment, a plurality of radiating elements and corresponding RF signal chain paths are formed in a plurality of groups arranged adjacent to each other.

[0362] Advantageously, each group includes at least two radiating elements and corresponding RF signal chain paths.

[0363] Advantageously, for each group, the corresponding radiating elements and RF signal chain paths are arranged in columns with respect to each other.

[0364] Advantageously, each group includes two or more radiating elements and RF signal chain paths.

[0365] A direct radiating array assembly is provided for use in a spacecraft antenna for transmitting and / or receiving RF radio signals in a predetermined frequency band. This assembly includes radiating elements that define the radiating surface of the DRA assembly. Each of the radiating elements forms a radiating surface and defines an element bottom surface arranged side by side with the element bottom surfaces of adjacent radiating elements. This assembly also includes an RF signal chain path for each radiating element. The RF signal chain path is at least partially disposed inside the element volume of the corresponding radiating element (which extends in a direction substantially perpendicular to the element bottom surface and opposite to the radiating direction). The RF signal chain path includes at least one heat generating unit. The DRA assembly also includes a plurality of temperature sink elements. Each of the temperature sink elements extends inside at least one element volume and is connected to a heat radiator. Each of the heat generating units is attached to one of the temperature sink elements to transfer heat to the temperature sink element. The plurality of temperature sink elements immediately and passively transfer the generated heat to the heat radiator and keep the heat generating units at a substantially uniform temperature with respect to other heat generating units.

[0366] The foregoing description provides examples of one or more apparatuses, methods, or systems. However, as will be understood by those skilled in the art, other apparatuses, methods, or systems are also included within the scope of the claims.

Claims

1. A DRA antenna (Direct Radiating Array Antenna) for transmitting or receiving RF signals (radio frequency radio signals) in a predetermined frequency band, a plurality of radiating elements defining a radiating surface of the DRA antenna, a plurality of RF signal chain paths, and a single beamforming network board having a plurality of electrical ports electrically connected to the RF signal chain paths, each of the RF signal chain paths is coupled to one of the radiating elements respectively, amplifying the RF signals transmitted or received by each of the radiating elements, each of the RF signal chain paths includes heat generating components, the DRA antenna includes a plurality of heat blades for passively transferring the heat generated by the heat generating components, the beamforming network board defines a first surface, the plurality of RF signal chain paths are arranged on a second surface substantially perpendicular to the first surface, characterized by the DRA antenna.

2. each of the RF signal chain paths includes heat generating components, the DRA antenna is provided with a heat spreader for passively cooling the DRA antenna by transferring the heat generated by the heat generating components of the RF signal chain paths, characterized by the DRA antenna according to claim 1.

3. each of the heat blades includes an upper surface functioning as a heat exchange interface of the DRA antenna, characterized by the DRA antenna according to claim 1.

4. each of the heat blades includes a heat pipe for passively transferring heat, characterized by the DRA antenna according to claim 3.

5. the heat pipe is a vibrating heat pipe for passively transferring heat, characterized by the DRA antenna according to claim 4.

6. The DRA antenna according to claim 1, wherein each of the heat blades is a solid metal heat blade that passively transfers heat.

7. Further comprising a plurality of radiation element modules, Each of the radiation element modules includes a subset of a plurality of radiation elements and a subset of a plurality of RF signal chain paths, Each of the subsets of the radiation elements defines a collective radiation element bottom surface, The DRA antenna according to claim 1, wherein each of the subsets of the RF signal chain paths is in a region below the projection plane when the bottom surface of each of the subsets of the radiation elements is viewed from the vertical direction.

8. Further comprising a plurality of SIP modules (system-in-package modules), Each of the plurality of SIP modules includes at least one BFIC (beamforming integrated circuit), The DRA antenna according to claim 1, wherein the SIP module is attached to a planar beamforming network board.

9. A first subset of the SIP modules is attached to a first surface of the beamforming network board, A second subset of the SIP modules is attached to a second surface of the beamforming network board, The DRA antenna according to claim 8, wherein the first surface and the second surface face each other.

10. The SIP module is attached to the beamforming network board as a plurality of double stacks, Each of the double stacks, A first SIP module attached to a first surface of the beamforming network board, And a second SIP module attached to a second surface of the beamforming network board. The DRA antenna according to claim 8, wherein the first SIP module and the second SIP module are connected to each other.

11. The DRA antenna according to claim 10, wherein each of the double stacks is thermally coupled to a heat blade that passively conducts heat.

12. The DRA antenna according to claim 9, wherein each of the first subsets of the SIP modules is thermally coupled to a heat blade that passively conducts heat.

13. The beamforming network is attached to a base plate, Each of the double stacks is thermally coupled to the base plate, The DRA antenna according to claim 10, wherein the base plate transfers heat to a heat blade for passively conducting heat from the heat generating components of the double stack.

14. The DRA antenna according to claim 1, wherein each of the RF signal chain paths is connected to a beamforming network board via a spring-loaded electrical connector.

15. Further comprising a plurality of SIP modules attached to a beamforming network board, The DRA antenna according to claim 1, wherein the plurality of SIP modules include at least one BFIC and a spring-loaded electrical connector that connects the SIP module to the beamforming network.

16. Further comprising a plurality of heat blades attached substantially perpendicular to the beamforming network board, The DRA antenna according to claim 1, wherein the plurality of RF signal chain paths are attached to the plurality of heat blades.

17. A satellite comprising the DRA antenna according to claim 1.

18. The satellite according to claim 17, characterized in that it is a low Earth orbit satellite.

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