Patent Description:
The present invention generally relates to satellite communication and, more particularly, relates to a hosted, compact, east-west, large-aperture, multi-reflector antenna system deployable with high-dissipation feed.

Existing satellite antenna systems are commonly specific to a satellite (bus) design and are not designed to be hosted by other satellite types and/or designs. For example, the mechanical design of the antenna system and the satellite are performed in an integrated design cycle, and the antenna system lacks any payload component, such as an electronically steered antenna (ESA), to be easily hosted. In such an antenna system, antenna pointing can be degraded by the thermal distortions due to lack or insufficiency of thermal management system.

<CIT> discloses an offset feed horn for propagating energy toward and receiving energy from a microwave reflector antenna for use especially in satellite-ground communication systems. <CIT> discloses an antenna system comprising an antenna feed aligned with a sub-reflector and a main reflector. <CIT> discloses an antenna feed assembly.

According to various aspects of the subject technology, methods and systems are disclosed for providing a hosted multi-reflector antenna system. The disclosed hosted multi-reflector antenna system has a number of advantageous features such as compactness, east-west orientation and large aperture, and is deployable with a high-dissipation feed, as further described herein.

In one aspect, an antenna system as disclosed in independent claim <NUM> is provided. Dependent claims <NUM>-<NUM> disclose advantageous embodiments.

In other aspects, a method of providing an antenna system as disclosed in independent claim <NUM> is provided. Dependent claims <NUM> and <NUM> disclose advantageous embodiments.

The foregoing has outlined rather broadly the features of the present disclosure so that the following detailed description can be better understood. Additional features and advantages of the disclosure, which form the subject of the claims, will be described hereinafter.

For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following descriptions to be taken in conjunction with the accompanying drawings describing specific aspects of the disclosure, wherein:.

The appended drawings are incorporated herein and constitute a part of this detailed description, which includes specific details for the purpose of providing a thorough understanding of the subject technology. However, it will be clear and apparent to those skilled in the art that the subject technology is not limited to the specific details set forth herein and can be practiced using one or more implementations. In one or more instances, well-known structures and components are shown in block-diagram form in order to avoid obscuring the concepts of the subject technology.

In some aspects of the present technology, methods and configurations are disclosed for providing a hosted multi-reflector antenna system. The hosted multi-reflector antenna system of the subject technology is a compact, east-west (E/W) oriented, and large-aperture antenna system that is deployable with a high-dissipation feed. Accommodation of features such as compactness, E/W orientation and large aperture in a hosted deployable multi-reflector antenna system with a high payload dissipation can be difficult due to a number of challenges. For example, the hosted payload design interdependency with a host space vehicle (e.g., a satellite, also referred to as a "bus") drives cost, complexity and risk. Further, mechanical interfaces may vary depending on the host space vehicle, which can have an unknown bus distortion and an unknown thermal interface. The other challenges include precise alignment, for instance, of a laser inter-satellite link (ISL), a telescope, and so on, and antenna mechanical alignments. Furthermore, integrated thermal designs are difficult to achieve. Such thermal challenges complicate antenna and payload design due to a number of factors such as the high thermal power (e.g., ~<NUM> watts) that can distort antenna optics, electronically steered antennas' (ESAs'), requirement of low temperatures for better performance and longer life, and anti-jam housing (faraday cage) that can complicate heat rejection.

The existing antenna systems lack any payload component, such as an ESA, to be easily hosted. In the existing antenna systems, antenna pointing can be degraded by the bus thermal distortions due to lack or insufficiency of thermal management system.

<FIG> is a schematic diagram illustrating an example of a hosted multi-reflector antenna system <NUM>, according to certain aspects of the disclosure. The example hosted multi-reflector antenna system <NUM> (hereinafter, antenna system <NUM>) is a compact, E/W oriented, and large aperture antenna system that can handle thermal dissipation of a high-dissipation feed (e.g., ~<NUM> watts). The antenna system <NUM> includes a number of antenna elements such as a primary reflector <NUM>, an aperture (iris) <NUM>, a subreflector <NUM> and an ESA <NUM>, that is part of a feed structure <NUM>. An anti-jam housing <NUM> encloses the subreflector <NUM>, the feed structure <NUM> and the ESA <NUM>.

The primary reflector <NUM> focuses a beam <NUM> into the aperture <NUM> that is also at a focal point of the subreflector <NUM>, which converts the received beam into a parallel beam directed at the ESA <NUM>. The beam <NUM> is, for example, a communication link between a host space vehicle (e.g., a space vehicle, such as a satellite) and a terrestrial station such as a satellite gateway or user terminal. The antenna system <NUM> is designed to be mechanically and thermally independent of the host space vehicle so that it can be mounted on different host space vehicle. The antenna system <NUM> can readily accommodate the thermal dissipation of the feed structure <NUM> of a high-dissipation feed, and is able to maintain the precise antenna alignment between the antenna elements such as the primary reflector <NUM>, the subreflector <NUM>, the aperture <NUM>, and the ESA <NUM>, as discussed in more detail herein.

The anti-jam housing <NUM> includes a composite structure and a thermal radiator layer that enable the antenna system <NUM> to handle the thermal dissipation of the feed structure <NUM>. The anti-jam housing <NUM> is mounted on an optical bench <NUM> that also supports the primary reflector <NUM> via a reflector-support structure, including a number of (e.g., three) booms <NUM> (<NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM>) and joint structures <NUM> (<NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM>). The optical bench <NUM> is decoupled from the host space vehicle to reduce any thermal elastic distortion (TED) from the host space vehicle so that the alignment between the primary reflector <NUM> and the subreflector <NUM> can be preserved and not disturbed by the TED of the host space vehicle. The optical bench further accommodates kinematic mounts (not shown in <FIG>, for simplicity) that are used to couple the antenna system <NUM> to the host space vehicle. The system <NUM> also includes locking fixtures <NUM> (e.g., <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM> (not visible in <FIG>)), which can lock components of the antenna system <NUM>, when not in use, in a stowed configuration. The locking fixture <NUM>-<NUM> is mounted on the anti-jam housing <NUM> and the locking fixtures <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM> (shown in <FIG>) are mounted on the optical bench <NUM> and a bus panel of the host space vehicle, respectively, via fixtures <NUM>, <NUM>-<NUM>, and <NUM>-<NUM> (not visible in <FIG>).

<FIG> is a schematic diagram illustrating a view 200A from a bus panel of an example of a hosted multi-reflector antenna system <NUM>, according to certain aspects of the disclosure. The view 200A shows the hosted multi-reflector antenna system <NUM> (hereinafter, antenna system <NUM>) from a bus panel of a host space vehicle (i.e. looking outboard from the host space vehicle) and depicts a front view of the primary reflector <NUM>, as it is folded back on to the locking fixtures <NUM> of <FIG>, and a back view of the optical bench <NUM>. The antenna system <NUM> is the same antenna system <NUM> of <FIG> in a folded configuration. Attached to the optical bench <NUM> are a hard mount <NUM> and three radial flexures <NUM> that are used to couple the antenna system <NUM> to the bus panel of a host space vehicle. The hard-mount <NUM> and three radial fixtures <NUM>, while attaching the antenna system <NUM> to the host space vehicle, thermally decouple the antenna system <NUM> from the host space vehicle so that the TED of the host space vehicle is prevented from affecting the alignment of the antenna system <NUM>.

<FIG> is a schematic diagram illustrating a perspective view 200B of an example of a hosted multi-reflector antenna system <NUM> in a stowed configuration, according to certain aspects of the disclosure. The antenna system <NUM> is the same antenna system <NUM> of <FIG> in a folded configuration, with the booms <NUM> folded and locked to the locking fixture <NUM>-<NUM>, and the primary reflector <NUM> is locked to the locking fixtures <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM>. The locking fixtures <NUM>-<NUM> and <NUM>-<NUM> are supported by fixtures <NUM>-<NUM> and <NUM>-<NUM>, respectively, which is coupled to the bus panel of the host space vehicle. The antenna system in the stowed configuration has a compact volume as shown by the dimensions in <FIG> below.

<FIG> is a schematic diagram illustrating various views <NUM>, <NUM>, <NUM> and <NUM> of an example of a hosted multi-reflector antenna system <NUM> in a stowed configuration, according to certain aspects of the disclosure. The view <NUM> shows the compact volume of hosted multireflector antenna system <NUM> (hereinafter, antenna system <NUM>), which is the same as the antenna system <NUM> of <FIG> in a stowed configuration, and clearly depicts folding of the primary reflector.

The view <NUM> is a top view that shows the antenna system <NUM> in the stowed configuration and depicts a dimension D1 (e.g., about <NUM> (about <NUM> inches)) of the primary reflector <NUM>, which allows an aperture size ranging from <NUM> to <NUM> (<NUM> to <NUM> inches) for the primary reflector <NUM>.

The view <NUM> is a side view of the antenna system <NUM> in the stowed configuration, and depicts dimensions D2 (e.g., about <NUM> (about <NUM> inches)) and D3 (e.g., about <NUM> (<NUM> inches)) of the antenna system <NUM>.

The view <NUM> is a side view of the antenna system <NUM> in the stowed configuration, and depicts dimension D4 (e.g., about <NUM> (about <NUM> inches)) of the antenna system <NUM>. The dimensions D1, D2, D3 and D4 of the antenna system <NUM> support the claim of a compact volume in the stowed configuration of the antenna system of the subject technology, which is one of the advantageous features of the disclosed antenna system.

<FIG> is a schematic diagram illustrating views <NUM> and <NUM> of an example of a hosted multi-reflector antenna system <NUM> in a stowed configuration and isolated from bus distortions, according to certain aspects of the disclosure. The view <NUM> shows the hosted multi-reflector antenna system <NUM> (hereinafter, antenna system <NUM>) in a stowed configuration. The view <NUM> depicts a low CTE composite structure <NUM> and a thermal subsystem <NUM>, which include an aluminum radiator, the subreflector <NUM>, the fixtures <NUM> and radial flexures <NUM>. The low CTE composite structure <NUM> and the thermal subsystem <NUM> can accommodate high thermal dissipation of the high-dissipation feed structure <NUM> of <FIG>.

The view <NUM> shows the antenna system <NUM> in a stowed configuration and coupled (e.g., bolted in) to a host space vehicle (e.g., satellite) <NUM>. The view <NUM> depicts the antenna system <NUM>, as coupled to a bus panel <NUM> of the host space vehicle <NUM> via the fixtures <NUM>, the hard mount <NUM>, and the radial flexures <NUM>, which mechanically and thermally isolate the primary reflector <NUM> and the optical bench, respectively, from the TED of the host space vehicle <NUM>.

<FIG> is a schematic diagram illustrating perspective views <NUM> and <NUM> of an example of a hosted multi-reflector antenna system <NUM> of the subject technology hosted on two different satellites. In the perspective view <NUM>, the hosted multi-reflector antenna system <NUM> (hereinafter, antenna system <NUM>) is mounted on a host space vehicle (e.g., satellite) <NUM>. The perspective view <NUM> also reveals a composite structure <NUM> that supports an aluminum thermal subsystem (i.e.
radiators) <NUM> of the antenna system <NUM>, which is crucial in eliminating TED and maintaining the alignment of the antenna elements, as described above.

In the perspective view <NUM>, the antenna system <NUM> is mounted on a host space vehicle (e.g., satellite) <NUM>, which is different from the host space vehicle <NUM>. The antenna system <NUM> is designed to be mechanically and thermally independent of the host space vehicle so that it can be mounted on different host space vehicles such as the host space vehicles <NUM> and <NUM>. The antenna system <NUM> is equipped to readily accommodate the thermal dissipation of a high-dissipation feed and to be able to maintain the precise antenna alignment, as discussed above.

<FIG> is a schematic diagram illustrating the structure of an anti-jam housing <NUM> and a thermal subsystem <NUM> of an example of a hosted multi-reflector antenna system, according to certain aspects of the disclosure. The anti-jam housing <NUM> is mounted on the optical bench <NUM> and includes the aperture <NUM>, the subreflector <NUM>, and a composite structure <NUM> that supports aluminum thermal radiators <NUM> and is internally coated with a radio-frequency (RF) absorber <NUM>. The anti-jam housing <NUM> excludes the feed structure <NUM>. The subreflector <NUM> is mounted to a first wall <NUM> of the anti-jam housing <NUM> via a coupling structure <NUM>. The feed structure <NUM>, including the ESA <NUM>, is kinematically mounted on a wall <NUM> of the anti-jam housing <NUM> and the respective ESA mounting access holes are covered via closeout panels <NUM>.

The thermal subsystem <NUM> includes a thermally conductive ESA mounting plate <NUM> over which the ESA <NUM> is mounted, and it is able to transfer high thermal power (e.g., about <NUM> watts) generated by the ESA <NUM> to the aluminum thermal radiators <NUM> via thermally conductive heat pipes <NUM>. The thermal subsystem <NUM> can dissipate the high thermal power generated by the ESA <NUM> and excludes wall <NUM>.

<FIG> is a schematic diagram illustrating a heat-dissipation mechanism in a thermal subsystem <NUM> of an example of a hosted multi-reflector antenna system, according to certain aspects of the disclosure. The thermal subsystem <NUM> includes the thermally conductive ESA mounting plate <NUM> over which the ESA <NUM> is mounted and the thermally conductive radiator <NUM>. The heat transferred from the ESA mounting plate <NUM> flows into the aluminum radiator <NUM> and dissipates to the environment. The ESA mounting plate <NUM> and the aluminum radiator <NUM> are coupled to the composite structure <NUM> via ESA flexures <NUM> and radiator flexures <NUM>, respectively.

<FIG> is a schematic diagram illustrating various views <NUM>, <NUM> and <NUM> of a heat-dissipation mechanism in the thermal subsystem of an example of a hosted multi-reflector antenna system, according to certain aspects of the disclosure. The view <NUM> is a top view of the thermal subsystem <NUM> of <FIG> and shows the aluminum ESA mounting plate <NUM>, the composite structure <NUM>, the heat pipes <NUM>, the aluminum radiator <NUM>, an ESA hard-mount <NUM>-<NUM> and ESA flexures <NUM>. The ESA hard-mount <NUM>-<NUM> and the ESA flexures <NUM> are used to mount the ESA mounting plate <NUM> on the composite structure <NUM>, while keeping them mechanically decoupled, so that thermal expansion <NUM> of the aluminum ESA mounting plate <NUM> is not transferred to the composite structure <NUM>. The front-view <NUM> is similar to the thermal subsystem <NUM> of <FIG>. The side-view <NUM> shows the ESA <NUM>, the radiator hard-mount <NUM>-<NUM> and the radiator flexures <NUM>.

<FIG> is a flow diagram illustrating an example of a method <NUM> of providing a hosted multi-reflector antenna system (e.g., <NUM> of <FIG>) of the subject technology. The method <NUM> includes coupling a primary reflector (e.g., <NUM> of <FIG>) via a number of booms (e.g., <NUM> of <FIG>) and joint structures (e.g., <NUM> of <FIG>) to an optical bench (e.g., <NUM> of <FIG>) (<NUM>). The method further includes positioning an anti-jam housing (e.g., <NUM> of <FIG>) comprising a low CTE composite structure (e.g., <NUM> of <FIG>) on the optical bench (<NUM>), and coupling a feed structure (e.g., <NUM> of <FIG>) including an ESA (e.g., <NUM> of <FIG>) to a first wall (e.g., <NUM> of <FIG>) of the anti-jam housing (<NUM>). A subreflector (e.g., <NUM> of <FIG>) is coupled to a second wall (e.g., <NUM> of <FIG>) of the anti-jam housing opposite the first wall to direct a reflected beam of the primary reflector onto the ESA (<NUM>). The hosted multi-reflector antenna system is configured to be mechanically and thermally independent of a host space vehicle (e.g., <NUM> of <FIG>) to accommodate thermal dissipation of the feed structure (e.g., via <NUM> of <FIG>) and to maintain a precise antenna system alignment (e.g., alignment of <NUM>, <NUM> and <NUM> of <FIG>) (<NUM>).

In some aspects, the subject technology may be used in various markets, including, for example, and without limitation, the satellite systems and communications systems markets.

Various components and blocks may be arranged differently (e.g., arranged in a different order, or partitioned in a different way), all without departing from the scope of the subject technology.

It is understood that any specific order or hierarchy of blocks in the processes disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes may be rearranged, or that all illustrated blocks may be performed. Any of the blocks may be performed simultaneously. In one or more implementations, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single hardware and software product or packaged into multiple hardware and software products.

The description of the subject technology is provided to enable any person skilled in the art to practice the various aspects described herein. While the subject technology has been particularly described with reference to the various figures and aspects, it should be understood that these are for illustration purposes only and should not be taken as limiting the scope of the subject technology.

A reference to an element in the singular is not intended to mean "one and only one" unless specifically stated, but rather "one or more. " The term "some" refers to one or more. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the above description.

Claim 1:
An antenna system (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) for a host space vehicle (<NUM>, <NUM>), the antenna system (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) comprising:
a primary reflector (<NUM>, <NUM>);
a feed structure (<NUM>) including an electronically steered antenna, ESA, (<NUM>);
a subreflector (<NUM>) configured to direct a reflected beam of the primary reflector (<NUM>, <NUM>) onto the ESA (<NUM>) and direct a reflected beam from the ESA (<NUM>) to the primary reflector (<NUM>, <NUM>); and
an anti-jam housing (<NUM>, <NUM>) enclosing the subreflector (<NUM>) and the ESA (<NUM>), and comprising an aperture (<NUM>),
wherein:
the antenna system (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) is configured to:
be thermo-elastically decoupled and thermally self-sufficient from the host space vehicle (<NUM>, <NUM>), accommodate a thermal dissipation of the feed structure (<NUM>), and maintain a precise antenna alignment.