A satellite communication terminal with an in-field replaceable cooling function

Abstract

A satellite communication, SATCOM, terminal (100) comprising a sealed housing (110) formed at least in part by a radome panel (115), the SATCOM terminal (100) comprising at least one heat dissipation 5 arrangement (210) configured on an exterior of the housing (110) and at least one heat conductor (310) extending from a location inside the housing (110) to the heat dissipation arrangement (210), where the housing (110) is arranged to releasably support one or more cooling modules (130) on an exterior of the housing (110), in connection to the heat 0 dissipation arrangement (210).

Description

[0001] TITLE

[0002] A satellite communication terminal with an in-field replaceable cooling function

[0003] TECHNICAL FIELD

[0004] The present disclosure relates to satellite communication systems, also known as SATCOM systems. There are disclosed cooling systems and housing structures with ingress protection for SATCOM terminals.

[0005] BACKGROUND

[0006] Satellite communication (SATCOM) terminals provide the ability to transmit and / or receive data from orbiting satellites. These terminals are essential for various applications, including military operations, disaster response, maritime communication, and remote internet access.

[0007] SATCOM terminals often operate in environments where ambient temperatures can be extremely high, such as in deserts or aboard ships in tropical waters. The electronic components within the terminal generate heat during operation, which must be dissipated to prevent overheating. Overheating can lead to equipment failure, reduced performance, and shortened lifespan of the terminal.

[0008] Protecting the terminals from dust and water ingress is essential to prevent short circuits, corrosion, and other forms of damage to the terminal. The terminal enclosure must therefore be designed to be waterproof or at least water-resistant, depending on the level of exposure expected. This complicates cooling of the terminal.

[0009] The design and operation of satellite communication terminals face significant challenges in terms of cooling due to the need for terminal ingress protection, i.e. , the need to dissipate heat and at the same time handle water and dirt in the operating environment. A SATCOM terminal is often operated in harsh remote environments far from service workshops. Hence, an in-field serviceable terminal design is preferred.

[0010] There is a need for improved SATCOM terminals with efficient cooling.

[0011] SUMMARY

[0012] It is an objective of the present disclosure to provide improved SATCOM terminals, in particular SATCOM terminals with a high level of ingress protection combined with efficient cooling.

[0013] This objective is at least in part obtained by a SATCOM terminal comprising a sealed housing formed at least in part by a radome panel. The SATCOM terminal comprises at least one heat dissipation arrangement configured on an exterior of the sealed housing and at least one heat conductor extending from one or more locations inside the sealed housing to the heat dissipation arrangement on the exterior of the sealed housing. The housing is arranged to releasably support one or more replaceable cooling modules on the exterior of the housing, in connection to the heat dissipation arrangement.

[0014] This way heat is transported from inside the sealed housing to its exterior in a sealed manner where it can be dissipated efficiently without compromising the ingress protection of the sealed housing. The cooling modules are releasably supported on the housing, which means that they can be replaced in a convenient manner. The cooling modules do not form part of the ingress protection of the housing. Thus, the cooling modules can be replaced in field without jeopardizing the ingress protection of the sealed housing. It is possible to design attachment interfaces on the outside of the sealed housing which permits use of different types of cooling modules having the same interface geometry.

[0015] The cooling modules that are releasably attached to the outside of the housing may comprise one or more fans, and preferably an array of fans, arranged on detachable cooling fan bays. A control unit of the terminal can be arranged to control a fan speed of the one or more fans in dependence of a temperature of the heat conductors or some other monitored temperature of the SATCOM terminal. The housing may comprise an electrical connection arranged to power the one or more fans. This electrical connection is a sealed connection which does not compromise the ingress protection of the sealed housing. The cooling fan bays constitute separate modules which can be stocked and replaced in field when the need arises. Different types of cooling modules can also be used depending on the intended application area of the terminal, i.e. , if the terminal will be used in an environment where water is likely to be an issue, such as on a ship, or if sand is expected to be of more concern than water ingress, such as in a desert environment.

[0016] The operation of the replaceable cooling modules may, generally, be configurable by the terminal control unit over a span of different cooling levels, such as from no cooling up to maximum cooling power in a number of predetermined steps or over a continuous cooling power span. The operation by the cooling modules may be controlled based on any of ambient temperature, temperature inside the sealed housing, temperature of the heat conductors, and so on. The operation by the cooling modules may be controlled such that a predetermined target temperature of the SATCOM terminal is maintained. If the monitored temperature or temperatures exceed the target temperature then cooling power can be increased by the control unit. If the monitored temperature is below the target temperature then cooling power can be decreased by the control unit.

[0017] According to some aspects the SATCOM terminal also comprises heating elements configured to increase a temperature of the SATCOM terminal. Selectively increasing the temperature of the SATCOM terminal in response to measuring a low temperature at one or more parts of the terminal may be particularly beneficial in cold operating environments, where ice may form on the outside of the sealed housing, and in particular on the outside of the radome panel, which may hamper operation of the SATCOM terminal.

[0018] In addition to facilitating in-field replacement without compromising the sealed housing, the replaceable cooling fan bays on the outside of the housing also improve the electromagnetic compatibility (EMC) characteristics of the SATCOM terminal. The EMC properties of the SATCOM terminal may be negatively affected by active fans arranged on the inside of the sealed housing. Hence, having replaceable cooling modules mounted on the outside of the sealed housing is beneficial for many reasons.

[0019] The sealed housing is preferably both dust proof and resistant to water spray. The housing is preferably categorized as an IP65 or IP66 housing.

[0020] The heat dissipation arrangement on the outside of the housing may comprise cooling flanges, i.e. , heat sinks comprising fins or the like that are arranged to efficiently dissipate thermal energy. The cooling flanges are configured to be exposed to a flow of cooling air, or form part of an interface to a heat exchanger that uses liquid coolant to transport heat away from the terminal.

[0021] According to a preferred aspect, the at least one heat conductor comprises a heat pipe extending from an evaporator module inside the sealed housing to a condenser module arranged in connection to the heat dissipation arrangement on the outside of the sealed housing. A network of heat pipes can be used to transport heat away from specific heat generating components inside the terminal to one or more condensers. Thus, the heat pipes extend from specific locations inside the sealed housing to the outside where heat can be dissipated. This provides a more effective cooling of hot spots compared to a more general heat transport arrangement based on, e.g., a flow of cooling air or convection cooling. In a condenser module, the gas in the heat pipes is transferred to liquid by cooling, and thru capillary effect, this liquid is transported back to an evaporator block. This process repeats itself as long as heat is generated at hot spots inside the sealed housing, such as by processing circuitry and by antenna elements inside the sealed housing.

[0022] The sealed housing preferably also comprises at least one venting valve arranged on an opposite side of the housing relative to the radome panel. The venting valve is configured to equalize the air pressure inside the sealed housing without compromising the ingress protection of the housing. The venting valve or valves also reduce the condensation that may occur due to temperature transients inside the sealed housing. It is an advantage that the venting valves are placed opposite to the radome panel, i.e. , underneath the SATCOM terminal, since the venting valves are more protected at this location compared to, e.g., at the sides of the SATCOM terminal. According to some aspects, one or more antenna arrays are supported inside the housing adjacent to and facing an inside of the radome panel. Respective heat conductors are embedded in the antenna arrays and extend from each antenna array to the heat dissipation arrangement of the SATCOM terminal.

[0023] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a / an / the element, apparatus, component, means, step, etc." are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated. Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following description. The skilled person realizes that different features of the present invention may be combined to create embodiments other than those described in the following, without departing from the scope of the present invention.

[0024] BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present disclosure will now be described in more detail with reference to the appended drawings, where

[0026] Figure 1 illustrates an example SATCOM terminal;

[0027] Figure 2 illustrates detachable cooling modules on a SATCOM terminal;

[0028] Figures 3-4 show a cross-section view of an example SATCOM terminal;

[0029] Figure 5 show details of a SATCOM terminal interior;

[0030] Figures 6-7 show a cross-section view of an example SATCOM terminal; and Figure 8 show details of a SATCOM terminal interior;

[0031] DETAILED DESCRIPTION

[0032] The invention will now be described more fully hereinafter with reference to the accompanying drawings, in which certain aspects of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments and aspects set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout the description.

[0033] It is to be understood that the present invention is not limited to the embodiments described herein and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.

[0034] Figure 1 illustrates an example SATCOM terminal 100. The terminal 100 comprises a housing 110 formed in part by a radome panel 115. The radome panel is formed in a material which allows radio waves to pass without significant attenuation. Common materials used for radomes include fiberglass, different types of plastics, or composite materials.

[0035] The terminal 100 has a flat form factor with a rectangularly shaped radome panel having dimensions on the order of 300-600mm by 550-950mm, and preferably about 450mm by 800mm. Example dimensions are indicated in, e.g., Figure 3 which will be discussed in more detail below. The radome panel 115 forms an upper lid of the housing 110 on the SATCOM terminal 100.

[0036] The SATCOM terminal 100 can be configured to support communication in, e.g., the Ka and the Ku satellite communication frequency bands. The terminals discussed herein are intended for use in outdoor environments, such as on land vehicles and on ships. Thus, ingress protection is important. The housing 110 is a sealed housing, which means that it is dust proof and also resistant to ingress of water. According to a preferred embodiment, the housing, including the radome and the interface 120 is categorized as an IP65 or IP66 sealed housing, which means that the sealed housing is dust proof and resistant to severe water spray and strong waterjets for at least 3 minutes.

[0037] The SATCOM terminal comprises an interface 120 configured to support transfer of data signals to and from the terminal 100, and also electrical power. The interface is a sealed interface that provide ingress protection at the connectors. This can be achieved, e.g., by the use of gaskets at the connectors of the interface 120.

[0038] The SATCOM terminals disclosed herein are high performance communication systems which generate a significant amount of heat in use. The terminal 100 often comprises steerable antenna arrays which focus transmitted and received radio signals on the satellite or satellites of interest. The heat generated by the active antenna systems and the processing circuitry required for transmitting and receiving high data rate satellite communication signals must be dissipated in an efficient manner, since otherwise the terminal risks damage and performance degradation due to overheating. However, a direct air flow through the terminal housing to cool hot components is not possible due to the ingress protection requirements of the terminal 100.

[0039] The SATCOM terminals 100 discussed herein comprise at least one heat dissipation arrangement 210 configured on an exterior of the housing 110, i.e., outside of the housing seal beyond the ingress protection boundary. This heat dissipation arrangement may be formed as cooling flanges or fins configured to be exposed to a flow of cooling air as in the illustrated examples, or as a heat exchanger in case a liquid-based cooling system is used in the cooling modules 130. The heat dissipation arrangement 210 functions as a heat sink for the terminal. Thermal energy generated inside the sealed housing can be transported via heat conductors from inside the sealed housing volume to the heat dissipation arrangement 210 on the outside of the sealed volume, where it is then efficiently dissipated by the cooling modules 130. The heat conductors 310 extends through the outer wall of the housing 110 in a sealed manner which does not compromise the ingress protection of the housing. This can be achieved, e.g., by letting condenser modules of a heat pipe network form the boundary to ambient environment of the sealed housing. Gaskets and seals can also be used to ensure the integrity of the ingress protection of the sealed housing 110.

[0040] According to a preferred embodiment, the heat conductors comprise a network of heat pipes which extend from one or more locations inside the housing 110 to the heat dissipation arrangement 210 on the outside of the housing 110. A heat pipe is a highly efficient thermal management device used in cooling systems to transfer heat from one location to another with minimal temperature drop. It operates on the principle of phase change and capillary action, allowing it to move large amounts of heat over relatively short distances with high efficiency. A heat pipe is typically a sealed, hollow tube made of a thermally conductive material like copper or aluminum. Inside the pipe, there is a small amount of working fluid (such as water, ethanol, or ammonia) and a wick structure that lines the inner walls. When heat is applied to one end of the heat pipe (the evaporator section), the working fluid absorbs this heat and evaporates, turning into vapor. This phase change from liquid to vapor requires energy, which helps to carry heat away from the hot spot. The vapor, now carrying the absorbed heat, travels through the hollow core of the heat pipe toward the cooler end (the condenser section). At the cooler end, the vapor releases its heat, condenses back into a liquid, and the released heat is dissipated through a heat sink or other cooling mechanism. The condensed liquid is then absorbed by the wick structure and transported back to the evaporator section by capillary action, where the cycle repeats.

[0041] Metal conductors can be used as heat conductor 310 instead of or as a complement to the network of heat pipes. A closed liquid coolant circuit inside the sealed housing 110 can also be used instead of or as a complement to the network of heat pipes to transport heat out from the terminal interior to the to the heat dissipation arrangement 210 on the outside of the housing 110. This closed coolant circuit then requires some form of coolant pump, if it is not operated based on passive convective heat transport. The coolant pump may form part of the cooling modules on the outside of the sealed housing, i.e., it does not have to be placed inside the sealed housing.

[0042] The sealed housing 110 optionally comprises at least one venting valve 150. The venting valve or valves are preferably located on an opposite side of the terminal compared to the radome 115 which normally faces upwards towards the sky. This way the venting valves are somewhat protected from, e.g., rain and splashes. Normally the radome 115 is the most exposed part of the terminal 100. This venting valve equalizes the air pressure inside the sealed housing to accommodate, e.g., changes in temperature. The venting valves form part of the ingress protection of the housing, i.e., the venting valves are dust proof and configured to resist water ingress. Ingress protected venting valves of this type are generally known and will therefore not be discussed in more detail herein.

[0043] With reference also to Figure 2, the housing 110 of the terminal 100 is arranged to releasably support one or more cooling modules 130 on an exterior of the housing 110. This means that the cooling modules 130 can be attached to the housing and then later detached without breaking any parts of the terminal 100. Bolts, snap-locks or interference fittings can be used to secure the cooling modules 130 to the housing 110 in a releasable manner.

[0044] The cooling modules are preferably arranged underneath extending portions of the radome panel 115. Thus, in use, the radome panel 115 protects the cooling modules 130 from rain and also from falling objects which may otherwise damage the cooling modules 130.

[0045] The cooling modules preferably extend along the sides of the sealed housing, as elongated modules. This shortens the path from the heat generating components inside the sealed housing to the boundary of the housing where the heat can be dissipated.

[0046] According to some aspects the cooling modules comprise an externally visible warning signal component configured to indicate malfunction of the cooling module, such as need for in-field replacement. The warning signal generated by the warning signal component may, e.g., comprise a light emitting diode (LED) and / or an audible signal generator such as a buzzer. The externally visible warning signal component may be powered from the same energy source as the cooling module and / or from a back-up power source such as a battery capable of generating the warning signal in the event that the cooling module has suffered a power outage.

[0047] The cooling modules 130 in this example are configured as detachable fan bays that comprise an array of fans 140 which generate a cooling air flow directed towards the heat dissipation arrangement 210. Between three and ten fans per cooling module may be suitable for providing efficient cooling. The cooling modules 130 in the example drawings comprise six fans each, arranged in respective rows extending along a side of the sealed housing. As noted above the radome panel 115 extends out over the fan bays, giving some protection from, e.g., rain and from falling objects.

[0048] A control unit of the terminal 100 can optionally be arranged to control a fan speed of the one or more fans 140 in dependence of a temperature of the heat conductors or other components in the terminal, so as to increase fan speed when cooling requirements is large and to reduce fan speed when there is not much heat being generated inside the sealed housing. Other types of cooling modules are also possible, such as liquid coolant modules, as will be discussed in more detail below.

[0049] The housing 110 optionally comprises an electrical connection arranged to power the one or more fans 140. However, a separate power feed can also be used to drive the fans 140. The same electrical connection can also be used to drive an electric pump in case a liquid coolant system is used.

[0050] The cooling modules 130 are releasably attached to the housing 110 as exemplified in Figure 2. The cooling modules 130 are separate from the housing in the sense that the ingress protection seal of the housing separates the internal volume of the terminal from the cooling modules. Hence, the internal volume of the terminal and the cooling modules form separate systems in terms of ingress protection. Leakage in a cooling module will not affect the integrity of the terminal itself. This means that the cooling modules can be replaced in a convenient manner in-field, without breaching the housing main ingress seals, which is an advantage.

[0051] According to an example embodiment not illustrated in the drawings, the heat dissipation arrangement 210 may also comprise a heat exchanger arranged to receive a flow of coolant via an input valve and to disperse the flow of coolant via an outlet valve. In this case the coolant transports heat away from the heat dissipation arrangement 210. Heat exchangers of this type are generally known and will therefore not be discussed in more detail herein. A heat exchanger forming part of a cooling module 130 can be releasably attached to the outside of the housing, in the same manner as the cooling fan bays in the illustrations.

[0052] Figures 5-8 show SATCOM terminals and details of SATCOM terminal interiors. Figure 3 indicates a cross-section H-H and Figure 6 indicates a crosssection L-L. These cross sections are shown in Figures 4 and 7, respectively, with more detailed views in Figures 5 and 8, respectively.

[0053] Heat generating components of the terminal 100 are schematically indicated by reference numeral 301. The heat generated by these components is transported out from the interior of the terminal by heat conductors 310 such as a network of heat pipes. The heat from the heat conductors 310 is then absorbed by the heat dissipation arrangement 320 on the exterior of the sealed housing. Thus, heat is transported out from the terminal interior without compromising the ingress protection seal of the housing.

[0054] According to preferred aspects, the at least one heat conductor 310 comprises a heat pipe extending from an evaporator module inside the sealed housing to a condenser module 320 arranged in connection to the heat dissipation arrangement 210 on the outside of the sealed housing. Heat pipes leading from the heat generating components inside the terminal to the heat dissipation arrangement on the exterior of the sealed housing are shown in Figure 5 and in Figure 8.

[0055] One or more antenna arrays 410 can be supported inside the housing adjacent to the radome panel 115. The respective heat conductors 310 are embedded in the antenna arrays and extend from each antenna array to the heat dissipation arrangement 210 of the SATCOM terminal 100. Processing circuitry 420 and power electronics are located in the interior volume 400 of the terminal, as illustrated in Figure 4 and in Figure 7. Thermal paste 510 can be used to improve the heat transfer between the heat pipes and the heat pipe condenser modules 320 of the terminal 100.

[0056] A combination of flat seals 520 and O-ring seals 530 can be used to ensure integrity of the ingress protection of the sealed housing.

Claims

CLAIMS1 . A satellite communication, SATCOM, terminal (100) comprising a sealed housing (110) formed at least in part by a radome panel (115), the SATCOM terminal (100) comprising at least one heat dissipation arrangement (210) configured on an exterior of the sealed housing (110) and at least one heat conductor (310) extending from a location inside the sealed housing (110) to the heat dissipation arrangement (210) on the exterior of the sealed housing (110), where the sealed housing (110) is arranged to releasably support one or more replaceable cooling modules (130) on the exterior of the sealed housing (110), in connection to the heat dissipation arrangement (210).

2. The SATCOM terminal (100) according to claim 1 , where the sealed housing (110) is dust proof and resistant to water spray and water jets for at least 3 minutes without water ingress.

3. The SATCOM terminal (100) according to claim 1 or 2, where the heat dissipation arrangement (210) comprises cooling flanges configured to be exposed to a flow of cooling air.

4. The SATCOM terminal (100) according to claim 3, where the cooling modules (130) comprises one or more fans (140) arranged on detachable cooling fan bays.

5. The SATCOM terminal (100) according to claim 4, comprising a control unit arranged to control a fan speed of the one or more fans (140) in dependence of a monitored temperature of the SATCOM terminal (100).

6. The SATCOM terminal (100) according to claim 4 or 5, where the housing (110) comprises an electrical connection arranged to power the one or more fans (140).

7. The SATCOM terminal (100) according to any previous claim, where the heat dissipation arrangement (210) comprises a heat exchanger arranged toreceive a flow of coolant via an input valve and to disperse the flow of coolant via an outlet valve.

8. The SATCOM terminal (100) according to any previous claim, where the at least one heat conductor (310) comprises a heat pipe extending to a heat pipe condenser module (320) arranged in connection to the heat dissipation arrangement (210).

9. The SATCOM terminal (100) according to any previous claim, where the at least one heat conductor (310) comprises a conduit for liquid coolant.

10. The SATCOM terminal (100) according to any previous claim, where the sealed housing (110) comprises at least one venting valve (150) arranged on an opposite side of the housing relative to the radome panel (115).11 . The SATCOM terminal (100) according to any previous claim, where one or more antenna arrays (410) are supported inside the housing adjacent to and facing an inside of the radome panel (115), where respective heat conductors (310) are embedded in the antenna arrays and extend from each antenna array to the heat dissipation arrangement (210) of the SATCOM terminal (100).

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