Patent ID: 12230863

DETAILED DESCRIPTION

The described features generally relate to antenna mounting systems, particularly those that suppress rotational movement of an antenna assembly relative to a vehicle. By suppressing rotational movement between an antenna assembly and a vehicle, the antenna assembly may have favorable alignment control characteristics as compared with mounting systems that allow rotational movement between an antenna assembly and a vehicle.

As described herein, antenna mounting systems that suppress rotational movement between an antenna assembly and a vehicle may employ an intermediate structure coupled between the antenna assembly and the vehicle. The intermediate structure may be coupled with one of the vehicle or the antenna assembly by way of a linear coupling, such as one or more linear bearings, which allow relative movement along a linear direction. The intermediate structure may be coupled with the other of the vehicle or the antenna assembly by way of a planar coupling, which may include one or more contact pads, one or more spherical rolling elements, or combinations of these elements. The antenna assembly may be coupled with the vehicle by way of a compliant coupling that provides a centering force between the antenna assembly and the vehicle. For example, the compliant coupling may include one or more wire rope isolators that provides a centering force based on relative translations and/or rotations between the antenna assembly and the vehicle.

This description provides examples, and is not intended to limit the scope, applicability or configuration of embodiments of the principles described herein. Rather, the ensuing description will provide those skilled in the art with an enabling description for implementing embodiments of the principles described herein. Various changes may be made in the function and arrangement of elements.

Thus, various embodiments may omit, substitute, or add various components as appropriate. For instance, it should be appreciated that the apparatuses may be arranged in an order different than arrangements described, and that various components may be added, omitted or combined. Also, aspects and elements described with respect to certain embodiments may be combined in various other embodiments. It should also be appreciated that the following systems and devices may individually or collectively be components of a larger system.

FIGS.1A and1Bshow diagrams of mobile communication systems100in accordance with aspects of the present disclosure. For example, mobile communication systems100may include antenna assemblies110mounted to vehicles105for communications with a target device120. The antenna assemblies110may each be any type of antenna, including various types of reflector antenna. Antenna assemblies110may be associated with a boresight111, which may represent a direction of highest signal gain for the respective antenna assembly110. Thus, it may be desirable to have a boresight111pointed in a direction of a target device120. In some examples the target device120can be a satellite, which may be following an orbital path (e.g., geostationary orbit, low earth orbit, medium earth orbit, etc.). Other examples of target devices120may include an aircraft in flight, a terrestrial target, such as another ground-based, water-borne, or airborne vehicle, or a ground-based antenna.

The antenna assemblies110may include an alignment control system112configured to direct the boresight111in the direction of a target device120, such as a satellite. An alignment control system112may be configured to adjust the orientation of the boresight111about one or more spatial axes of an antenna assembly110, providing, for instance, azimuth (e.g., horizontal) positioning of the boresight111and elevation (e.g., vertical) positioning of the boresight111. In this manner, an antenna assembly110can take advantage of a directional antenna that has increased signal gain along the direction between the antenna assembly110and the target device120. With suitable alignment of the boresight111with a target device120, an antenna assembly110may support communication with the target device over one-way or two-way communication links.

FIG.1Aillustrates a mobile communication system100-awhere an antenna assembly110-ais mounted to vehicle105-aby antenna mount115. The antenna assembly110-amay be configured to support communications via uplink and/or downlink transmissions with the target device120-a. The antenna assembly110-amay be associated with a boresight111-a, which may represent a direction corresponding to a highest signal gain of the antenna assembly110-a. The antenna assembly110-amay include an alignment control system112-aconfigured to direct the boresight111-ain the direction of a target device120-a.

Antenna mount115may be an example of an unconstrained antenna mount that includes a compliant coupling between the antenna assembly110-aand the vehicle105-a, but does not constrain translational or rotational degrees of freedom between the antenna assembly110-aand the vehicle105-a. The compliant coupling of the antenna mount115may provide a centering force between the antenna assembly110-aand the vehicle105-a, directed in opposition to translations125-abetween the antenna assembly110-aand the vehicle105-aand/or rotations130-abetween the antenna assembly110-aand the vehicle105-a(e.g., translations or rotations from a nominal position). In this arrangement, the antenna mount115may attenuate the transmission of loading and/or accelerations from the vehicle105-ato the antenna assembly110-a, where such loading and/or accelerations may be due to vehicle-borne vibrations (e.g., due to engines, turbines, rotors, etc.), vehicle movements, loads and/or accelerations externally imparted on the vehicle, and the like.

The antenna mount115may support attenuation of such loading and accelerations by converting at least a portion of the kinetic energy of various components into potential energy stored by one or more compliant members of the antenna mount115. In some examples a portion of the kinetic energy and/or stored potential energy may be dissipated by the compliant member(s), or another portion of the antenna mount115, by way of dynamic friction, viscous damping, electromagnetic damping, or any other suitable means. These conversions of energy may attenuate loads and/or accelerations from the vehicle105-a, which may reduce mechanical damage and/or fatigue of the antenna assembly110-aas compared with a fully-constrained antenna mount which constrains both translational and rotational movement (e.g., a rigid antenna mount).

The conversion of kinetic energy into potential energy of the antenna mount115-amay be associated with relative displacement between the antenna assembly110-aand the vehicle105-a. Thus, in the example of an unconstrained antenna mount115, various accelerations of the vehicle105-amay be translated into translations125-aand rotations130, which may cause the antenna boresight alignment to vary, with reference to the vehicle105-a, across a boresight alignment range135-a. To isolate the effect of boresight alignment range135-adue to relative displacement between the antenna assembly110-aand the vehicle105-a, the arrangement ofFIG.1Ais shown with reference to the vehicle105-a, and therefore omits movements of the vehicle itself. The translations125-aand rotations130-a, caused by translational or vibrational inputs from the vehicle105-a, may be based at least in part on the natural frequency of the system (e.g., based at least in part on mass, moment of inertia, stiffness, damping, etc.). Accordingly, such translations125-aand/or rotations130may be particularly severe when the frequency of accelerations and/or loads from the vehicle is at or near a natural frequency of sprung mass associated with the antenna assembly110-a(e.g., due to resonance).

As shown by the example of mobile communication system100-a, the combination of translations125-aand rotations130-amay lead to a relatively broad boresight alignment range135-arelative to the vehicle105-a, which may impair the ability of the alignment control system112-ato point the boresight111-atowards the target device120-a. Rotational movement, such as rotations130-a, may be particularly problematic because angular errors are amplified over the distance between the antenna and a target device120. In other words, rotations130between a vehicle105and an antenna assembly110may be directly translated into angular pointing errors. When such errors occur at a speed and/or frequency higher than the alignment controller can compensate for, and/or when such errors are not measured and accounted for, the boresight111-amay depart from an alignment with the target device120-a, and a communication link between the antenna assembly110-aand the target device120-amay be lost. Translations125-amay not be associated with such conditions, because the effect of translations125-aon boresight alignment is not amplified over the distance between the antenna assembly110-aand the target device120-a. Thus, rotations130-amay result in significantly greater alignment errors between the antenna assembly110-aand the target device120than translations125-a.

FIG.1Billustrates a mobile communication system100-bwhere an antenna assembly110-bis mounted to vehicle105-bby an antenna mount140. The antenna assembly110-bmay be configured to support communications via uplink and/or downlink transmissions with the target device120-b. The antenna assembly110-bmay be associated with a boresight111-b, which may represent a direction corresponding to a highest signal gain of the antenna assembly110-b. The antenna assembly110-bmay also include an alignment control system112-bconfigured to direct the boresight111-bin the direction of a target, such as the target device120-b.

Antenna mount140may be an example of a constrained antenna mount that constrains rotational motion along one or more axes. For example, the antenna mount140may include a planar coupling which suppresses rotational movement of the antenna assembly110-brelative to the vehicle105along any axis parallel to a plane associated with the planar coupling. The plane may, for example, be a reference plane for an elevation angle of the antenna assembly110-b(e.g., a reference plane for determining an elevation axis of the alignment control system112-b), and in some examples may be parallel to a horizontal plane of the vehicle105-b. Thus, in some examples, antenna mount140may suppress rotational movement of the antenna assembly110-babout a roll axis of the vehicle105-b, a pitch axis of the vehicle105-b, or both of these axes.

In some examples the antenna mount140may permit rotations130-b, which may be aligned about a yaw axis of the vehicle105-band/or an azimuth axis of the antenna assembly110-b. Thus, in some examples the antenna assembly110-bmay experience translations125-brelative to the vehicle105-bin any direction, and rotations130-babout a yaw axis. Such motions may be associated with a boresight alignment range135-c(e.g., a circular or elliptical boresight alignment range135-bdue to translations125-b, which is swept horizontally as a result of rotations130-babout a yaw axis). In other examples the antenna mount140may not permit any rotations130-b, or may otherwise minimize rotations130-babout a yaw axis, and may therefore be configured to only permit translations125-b. In such examples the boresight range may be associated with the circular or elliptical boresight alignment range135-bdue to translations125-b.

Thus, according to various aspects of the present disclosure, an antenna mount140may be provided to reduce a boresight alignment range135, thereby reducing boresight alignment errors caused by relative motions between an antenna assembly110and a vehicle105. Such an antenna mount140may suppress rotational movement of an antenna assembly relative to a vehicle along any axis in a plane associated with a planar coupling coupled between an antenna assembly110and a vehicle105, while also attenuating the transmission of certain loads and/or accelerations from the vehicle105to the antenna assembly110.

FIG.2shows a diagram of a mobile communication system200including a vehicle-mounted antenna assembly110-c, in accordance with aspects of the present disclosure. The mobile communication system200includes an example of an antenna mount140-afor attenuating transmission of loads and accelerations from a vehicle105-cwhile also suppressing rotational movement between an antenna assembly110-cand the vehicle105-c. The antenna mount140-amay include a first structure205-a, a second structure210-a, and a third structure215-a. In the example of the mobile communication system200, the first structure205-ais mounted to, or is a portion of the vehicle105-c, the third structure215-ais mounted to, or is a portion of the antenna assembly110-a, and the second structure is an intermediate structure coupled to the first structure and the second structure. The antenna assembly110-cmay also include an alignment control system112-c, used to align the boresight111-cwith a target device120(not shown).

The structures described herein (e.g., a first structure205, a second structure210, or a third structure215) are each rigid components that may provide interfaces for connecting neighboring components, such as the described antenna assemblies110, vehicles105, and couplings. In various examples, each structure may be formed by one or more components or subcomponents. The structures, or subcomponents thereof, may be formed by any suitable method(s), including any one or combination of machining, drilling, tapping, riveting, or using materials such as plate material, billet, castings, injection moldings, and the like. In some examples the described structures or subcomponents of the structures may be formed directly by additive manufacturing techniques such as 3D printing. Each structure may also provide a mounting interface for additional components of a mobile communication system such as sensors, cables, hoses, or any other supporting subcomponents for operating an antenna assembly110.

The mobile communication system200may be operating relative to a global coordinate system250, which may include principal directions as shown. In some examples, the principal directions may reflect a polar coordinate system, such as a latitude, longitude, and elevation with reference to the center of the earth, or other suitable reference surface (e.g., sea level). In various examples a mobile communication system200may be operating relative to any suitable coordinate system. In order to support a communication link with a target device120, the alignment control system112-cmay perform calculations to align the boresight111-calong a direction between the mobile communication system200and the target device120. In some examples, the alignment control system112-cmay perform calculations to determine an alignment based on a position of the mobile communication system200in the global coordinate system250and a position of the target device120in the global coordinate system250.

The vehicle105-cmay be associated with a vehicle coordinate system260, which may be aligned with the vehicle itself. For example, the vehicle coordinate system260may be a Cartesian coordinate system with axes aligned along a fore-aft direction of the vehicle105-c, a lateral (e.g., left/right) direction of the vehicle105-c, and a vertical (up/down) direction of the vehicle105-c. Rotations of the vehicle105-cmay include roll rotations about the fore-aft direction, pitch rotation about the lateral direction, and yaw rotations about the vertical direction.

The antenna assembly110-amay be associated with an antenna assembly coordinate system270, which may be aligned with the base of the antenna assembly110-c(e.g., the third structure215-a). Like the vehicle coordinate system260, the antenna assembly coordinate system270may also be a Cartesian coordinate system with axes aligned along a fore-aft direction of the vehicle, a lateral (e.g., left/right) direction, and a vertical (up/down) direction. Rotations of the vehicle may be characterized by a roll rotation about the fore-aft direction, pitch rotation about the lateral direction, and yaw rotations about the vertical direction. However, under various circumstances the vehicle coordinate system260and the antenna assembly coordinate system270may be translationally offset or rotationally misaligned, such as when there is relative displacement and/or relative rotation between the first structure205-aand third structure215-a. In some examples the compliant coupling230-amay provide a centering force between the first structure205-aand the third structure215-athat act in a manner to reduce such translational offset and/or rotational misalignment.

The antenna assembly110-amay also have a system of boresight alignment angles280, which may be associated with the principal angular degrees of freedom controlled by the alignment control system112-cfor aligning the boresight111-ctowards a target device. For example, the system of boresight alignment angles280may include an azimuth angle281, representing an angle of alignment in a plane282(e.g., about an azimuth axis perpendicular to the plane). In some examples the plane282may be parallel to the fore-aft and lateral directions of the antenna assembly110-c, and the azimuth angle may be measured as an angle from the forward direction of the antenna assembly coordinate system270. In some examples, the plane282may be parallel to a plane associated with the planar coupling225-a, which may also be parallel with the horizontal plane of the vehicle105-c(e.g., a plane parallel with the fore-aft direction and the lateral direction of the vehicle). The system of boresight alignment angles280may also include an elevation angle283, representing an angle of alignment measured out-of-plane from the plane282(e.g., as pointing towards a vertical direction). In some examples, the system of boresight alignment angles280may also include a polarization angle284, representing an angle of alignment measured about the boresight111-c, and associated with principal direction(s) of polarization of signals communicated via the antenna assembly110-c

The antenna mount140-amay include a linear coupling220-abetween the first structure205-aand the second structure210-athat constrains relative movement between the first structure205-aand the second structure210-ato be along a linear direction. In some examples the linear direction may be aligned with the vertical direction of the vehicle105-c, the vertical axis of the antenna assembly110-c, and/or the azimuth axis of the alignment control system112-c. The linear coupling220-amay be formed by one or several components, which may be coupled with the first structure205-aand the second structure210-a. For example, the linear coupling220-amay include one or more linear bearings aligned along the linear direction. Such linear bearings may include or be otherwise referred to as a rolling element (e.g., ball, cylinder, tapered roller, etc.) bearing assembly, a ball bearing sliding bearing, a crossed roller sliding bearing, a plain bearing, a compound slide, a rack slide, a journal bearing. a linear bushing, and the like. Linear bearings may include a shaft or raceway that guides the motion of, or otherwise constrains the motion of a bearing block along the linear direction, and in the example of antenna mount140-a, a shaft or raceway may be coupled with either the first structure205-aor the second structure210-a. In some examples, such as linear bearings having cylindrical shafts or raceways, or linear bearings with unsuitable load-carrying capacity in torsional directions about the axis of the linear bearing, linear coupling220-amay include two or more linear bearings in combination to prevent relative rotations between the first structure205-aand the second structure210-aabout an axis parallel to the cylindrical shafts or raceways.

The antenna mount140-amay also include a planar coupling225-abetween the second structure210-aand the third structure215-athat allows relative movement between the second structure210-aand the third structure215-awithin a plane that is non-parallel with the linear direction. In some examples the plane may be a reference plane associated with the planar coupling225-a, which may be parallel to a horizontal plane of the vehicle105-cand/or a horizontal plane of the antenna assembly110-c. The plane associated with the planar coupling225-amay also be parallel to the plane282from which elevation angle is defined and/or measured for the alignment control system112-c. In some examples the plane associated with the planar coupling225-amay be perpendicular to the linear direction associated with the linear coupling220-a.

The planar coupling225-amay be formed by one or several components, which may be coupled with the second structure210-aand the third structure215-a. For example, the planar coupling225-amay include one or more contact points where the second structure210-aand third structure215-aare in physical contact. The contact point(s) may include spherical rolling elements (e.g., transfer bearings, ball transfers, etc.) or sliding surfaces (e.g., oil-impregnated bronze, ultra-high-molecular-weight (UHMW) polymer, graphite-lubricated pads, etc.) In other examples the planar coupling225-amay include linear bearings aligned in different directions (e.g., aligned perpendicular to each other and aligned parallel to the plane of the planar coupling225-a), and separated from each other by an intermediate structure. In arrangements such as this, the planar coupling225-amay provide two linear degrees of freedom (e.g., as aligned with respective linear bearings), and may suppress in-plane rotations (e.g., prevent relative rotation between the second structure210-aand the third structure215-aabout an axis perpendicular to the plane).

In some examples the contact points of planar coupling225-amay all be in physical contact within the same plane. In other examples the contact points may be offset at different distances from a plane of the planar coupling225-abut may still support the relative movement between the second structure210-aand the third structure215-abeing within the plane associated with the planar coupling225-a. In a planar coupling225-athat includes contact points, the contact points may be provided with a compressive preload that maintains physical contact under certain loads and/or accelerations of the mobile communication system200. In such examples, the planar coupling225-amay also include one or more compliant members that support the compressive preload of the contact points. For example, the planar coupling225-amay include one or more springs coupled between the second structure210-aand the third structure215-a, where the spring(s) have a tensile preload that supports the compressive preload of the contact points. In some examples the planar coupling225-amay include one or more springs coupled between the first structure205-aand the second structure210-a, where the spring(s) have a compressive preload that supports the compressive preload of the contact points. Thus, in some examples of an antenna mount140-a, the planar coupling225-amay also include one or more components coupled between the first structure205-aand the second structure210-a.

Thus, by combining a linear coupling220-aand a planar coupling225-avia the second structure210-a, the change in relative position between the first structure205-aand the third structure215-aof the antenna mount140-amay include translations (e.g., translations125-bdescribed with reference toFIG.1B) between the first structure205-aand the third structure215-ain any direction, and in some examples may also include relative rotation translations (e.g., rotations130-bdescribed with reference toFIG.1B) between the first structure205-aand the third structure215-aabout an axis that is perpendicular to the plane associated with the planar coupling225-a.

The antenna mount140-amay also include a compliant coupling230-athat couples the first structure205-awith the third structure215-a, and provides a centering force between the first structure205-aand the third structure215-athat is based at least in part on a change in relative position between the first structure205-aand the third structure215-a. For example, the compliant coupling230-amay provide a force in one or more directions that opposes an offset between the vehicle coordinate system260and the antenna assembly coordinate system270, and may also provide a torque about one or more axes that opposes an angular misalignment between the vehicle coordinate system260and the antenna assembly coordinate system270. In combination with the linear coupling220-aand the planar coupling225-a, the compliant coupling230-amay therefore be primarily directed to providing a centering force opposing translation along the linear direction of the linear coupling220-a, a centering force opposing translations in the plane associated with the planar coupling225-a, and in examples where in-plane rotations are not suppressed, a centering torque that opposes rotations about an axis perpendicular to the plane associated with the planar coupling225-a. To provide the centering force, the compliant coupling230-amay include wire rope isolators, coil springs, leaf springs, compliant blocks of a material such as rubber, or any suitable component or combination of components.

In some examples the compliant coupling230-amay also provide a force between the first structure205-aand the third structure215-athat is based at least in part on relative motion between the first structure205-aand the third structure215-a. Such force may be provided by dynamic friction (e.g., by friction between wires of a wire rope dampers), viscous damping (e.g., by hydraulic cylinders, shock absorbers, etc.), electromagnetic damping (e.g., by permanent magnets and conductors), or other suitable means. In some examples, forces based on relative motion may be provided by means other than the compliant coupling230-a, such as components coupled between the first structure205-aand the second structure210-a(e.g., separate components or components integrated with the linear coupling220-a), or components coupled between the second structure210-aand the third structure215-a(e.g., separate components or components integrated with the planar coupling225-a)

In some examples the compliant coupling230-amay have a stiffness along the linear direction (e.g., a linear direction associated with the linear coupling220-a) that is different from a stiffness along the planar direction (e.g., in directions parallel to the plane associated with the planar coupling225-a). Such characteristics may be specifically designed for the system to tune desired natural frequencies of motion of the antenna assembly with respect to the vehicle, and/or to provide desired isolation characteristics for attenuating the transmission of loads or accelerations from the vehicle105-cto the antenna assembly110-c. For example, it may be desirable to have greater attenuation of vibrations (e.g., a lower cutoff frequency of attenuation) along a vertical direction of the vehicle. Accordingly, it may be preferable to have a relatively low stiffness along the linear direction. In some examples, roll and pitch dynamics of the vehicle105-cmay lead to relatively high transverse accelerations of the antenna assembly110-a(e.g., accelerations parallel to the plane associated with the planar coupling225-a), and it may be preferable to suppress the relative in-plane motions that may result between the second structure210-aand the third structure215-a(e.g., limiting excursions of the planar coupling225-a). Thus, in some examples it may be desirable to have relatively high stiffness for motions between the first structure205-aand the third structure215-ain directions parallel to the plane associated with the planar coupling. In other examples, various other considerations may be taken in to account when determining a desired stiffness in various directions.

In some examples the compliant coupling230-amay include two or more compliant members distributed about an axis of symmetry perpendicular to the plane. For example, the compliant members may be distributed in a circular pattern, a square pattern, or a polygonal pattern about the axis of symmetry. The distance of the compliant members from the axis of symmetry may be chosen to provide a desired rotational stiffness about the axis of symmetry. For example, for a given translational stiffness in the in-plane directions of the planar coupling225-a, the compliant members may be moved farther from the axis to provide higher rotational stiffness, or moved closer to the axis of symmetry to provide lower rotational stiffness. Such design freedom may be used to balance natural frequency and isolation characteristics between translational effects and rotational effects.

In some examples, a sprung mass associated with the antenna assembly110-cmay be located at a position coincident with the axis of symmetry. For example, it may be desirable to prevent, or otherwise minimize translational accelerations of the vehicle105-cfrom being converted into rotations of the antenna assembly110-c. More specifically, for examples where the plane associated with the planar coupling225-ais parallel to the horizontal axis of the vehicle105-cand perpendicular to the azimuth axis of the alignment control system112-c, it may be desirable to prevent horizontal translational accelerations and/or pitch or roll accelerations of the vehicle105-cfrom being converted into yaw accelerations of the in-plane sprung mass290-athat includes the antenna assembly110-a. As used herein, “in-plane sprung mass” refers to the mass having degrees of freedom in the direction of the plane associated with the planar coupling. Thus, in the example of mobile communication system200, the in-plane sprung mass290-aincludes the antenna assembly110-c, the third structure215-a, and at least a portion of the planar coupling225-aand the compliant coupling230-a. In other examples, an in-plane sprung mass290may include an antenna assembly110along with a different combination of components of an antenna mount140. In order to minimize yaw rotations of the antenna assembly110-c, it may therefore be desirable to locate the center of gravity of the in-plane sprung mass290-athat includes the antenna assembly110-cto be coincident with the axis of symmetry of compliant members of the compliant coupling230-c.

An antenna mount140may be configured according to various dynamic requirements, such as natural frequencies with respect to various motions. For example, an antenna assembly110may, in combination with an antenna mount140, exhibit different natural frequencies with respect to translations in the linear direction associated with a linear coupling220, translations parallel to the plane associated with a planar coupling225, and rotations about an axis perpendicular to the plane associated with a planar coupling225. As is known in the art, natural frequencies of components may be based at least in part on an associated mass or moment of inertia of associated components, and a stiffness coupling such components to parts of an assembly. As shown in mobile communication system200, the associated mass for the motions of the antenna assembly110-cmay be different depending on the configuration of an antenna mount140.

For example, a natural frequency of the antenna assembly110-calong the linear direction associated the linear coupling220-amay be based on the sprung mass having a degree of freedom in the linear direction. Thus, the natural frequency of the antenna assembly110-calong the linear direction may be based at least in part on the linearly sprung mass295-a, which includes the combined mass of the antenna assembly110-c, the third structure215-a, the planar coupling225-a, the second structure210-a, and at least a portion of the linear coupling220-aand the compliant coupling230-a. Similarly, the natural frequency of the antenna assembly110-cfor translations parallel to the plane associated with the planar coupling225-amay be based at least in part on the in-plane sprung mass290-a, which includes the combined mass of the antenna assembly110-cand the third structure215-a, and at least a portion of the planar coupling225-aand the compliant coupling230-a. Likewise, a natural frequency of the antenna assembly110-cfor rotations about an axis perpendicular to the plane associated with the planar coupling225-amay be based at least in part on the moment of inertia of the in-plane sprung mass290-a, which includes the combined moment of inertia of the antenna assembly110-cand the third structure215-a, and at least a portion of the planar coupling225-aand the compliant coupling230-a.

In some examples it may be desirable to consider interactions between natural frequencies of the mobile communication system200and frequency response for the alignment control system112-c. For example, to reduce resonant characteristics of the system, it may be desirable to design the system to have mechanical natural frequencies that are greater than a frequency response of the alignment control system112-c. In this way the mechanical system can be relatively stiff, or even negligibly compliant (e.g., essentially rigid) from the perspective of the alignment control system112-c. In other words, the mechanical system may be rigid enough that the effect of relative motions between the first structure205-aand the third structure215-amay be ignored for the purposes of boresight alignment control. This may have a particular advantage for measuring boresight alignment by the antenna assembly110-c, since no additional sensing would be required between the antenna assembly110-cand the vehicle105-c.

For the antenna mount140-ato be suitably stiff for azimuth control, for example, it may be desirable for the antenna mount140-ato be designed with a natural frequency of rotations between the antenna assembly110-cand the vehicle105-cabout an axis perpendicular to the plane associated with the planar coupling225-ato be at least a multiple of two greater than a cutoff frequency of azimuth controller of the alignment control system112-c. In other examples, different multiples may be used between the natural frequencies and associated controller cutoff frequencies, which may be based at least in part on a tolerable amount of error in the alignment of boresight111-cwith a target device120(not shown). In other examples, natural frequencies may not be a predominant design factor. For example, in some implementations it may be desirable to increase the sprung mass associated with an antenna assembly110so that actuation of alignment control system112-ccauses a lesser degree of acceleration of the sprung mass (e.g., by way of mass damping). Thus, various considerations of mass, stiffness, natural frequency, and controller response frequency may be used to design a mobile communication system200according to desired characteristics.

FIG.3shows a diagram of a mobile communication system300including a vehicle-mounted antenna assembly110-d, in accordance with aspects of the present disclosure. The mobile communication system300includes an example of an antenna mount140-bfor attenuating transmission of loads and accelerations from a vehicle105-dwhile also suppressing rotational movement between an antenna assembly110-dand the vehicle105-d. The antenna mount140-bmay include a first structure205-b, a second structure210-b, and a third structure215-b, which may be examples one or more aspects of the corresponding components described with reference toFIG.2. The antenna assembly110-dmay also include an alignment control system112-d, used to align the boresight111-dwith a target device120(not shown).

In contrast with mobile communication system200, the third structure215-bis mounted to, or is a portion of the vehicle105-d, and the first structure205-bis mounted to, or is a portion of the antenna assembly110-din mobile communication system300. Accordingly, mobile communication system300may include a planar coupling225-bcoupled between the vehicle105-dand an intermediate structure (e.g., second structure210-b) and a linear coupling220-bcoupled between the antenna assembly110-dand an intermediate structure (e.g., second structure210-b). However, similarly to the mobile communication system200, mobile communication system300includes a compliant coupling230-bcoupled between the first structure205-band the third structure215-b. Each of the planar coupling225-b, the linear coupling220-b, and the compliant coupling230-bmay be examples one or more aspects of the respective components described with reference toFIG.2. Thus, the antenna mount140-bmay represent an alternate configuration for suppressing rotational movement of the antenna assembly110-drelative to the vehicle105-d.

In some examples, a sprung mass associated with the antenna assembly110-dmay be coincident with an axis of symmetry associated with compliant members of the compliant coupling230-b. In the example of mobile communication system300, the in-plane sprung mass290-bmay include the antenna assembly110-d, the first structure205-b, the linear coupling220-b, the second structure210-b, and at least a portion of the planar coupling225-band the compliant coupling230-b. In order to minimize yaw rotations of the antenna assembly110-d, it may therefore be desirable to locate the center of gravity of the in-plane sprung mass290-bthat includes the antenna assembly110-dto be coincident with the axis of symmetry of compliant members of the compliant coupling230-d.

In some examples the antenna mount140-bmay be configured according to different dynamic requirements than antenna mount140-adescribed with reference toFIG.2. For example, a natural frequency of the antenna assembly110-dalong the linear direction associated the linear coupling220-bmay be based on the sprung mass having a degree of freedom in the linear direction. Thus, the natural frequency of the antenna assembly110-dalong the linear direction may be based at least in part on the linearly sprung mass295-b, which includes the combined mass of the antenna assembly110-d, the third structure215-band at least a portion of the planar coupling225-band the compliant coupling230-b. Similarly, the natural frequency of the antenna assembly110-dfor translations parallel to the plane associated with the planar coupling225-bmay be based at least in part on the in-plane sprung mass290-b, which includes the combined mass of the antenna assembly110-d, the third structure215-b, the linear coupling220-b, the second structure210-b, and at least a portion of the planar coupling225-band the compliant coupling230-b. Likewise, a natural frequency of the antenna assembly110-dfor rotations about an axis perpendicular to the plane associated with the planar coupling225-bmay be based at least in part on the moment of inertia of the in-plane sprung mass290-b, which includes the combined moment of inertia of the antenna assembly110-d, the third structure215-a, the linear coupling220-b, the second structure210-b, and at least a portion of the planar coupling225-band the compliant coupling230-b.

Thus, as compared to the antenna assembly110-cdescribed with reference toFIG.2, for components having the same inertial properties and compliant couplings230having the same stiffness, the antenna assembly110-dmay be characterized as having a higher natural frequency for motions in the linear direction associated with the linear coupling220-b, and lower natural frequency for translations parallel to, and rotations about an axis perpendicular to the plane associated with the planar coupling225-b(e.g., lower in-plane natural frequency).

FIGS.4A and4Bshow diagrams of mobile communication systems400-aand400-bincluding different arrangements of antenna mounts140for suppressing rotational movement between an antenna assembly110and a vehicle105, in accordance with aspects of the present disclosure. Antenna mounts140may include a first structure205, a second structure210, a third structure215, a linear coupling220, a planar coupling225, and a compliant coupling230, each of which may be examples of one or more aspects of the respective components described with reference toFIGS.2-3. As previously described, contacting elements of a planar coupling225-cmay have a compressive preload to maintain contact through various system movements or vibrations. The arrangements of mobile communication systems400-aand400-bshow examples of different configurations for providing such a compressive preload in a planar coupling225.

FIG.4Aillustrates an antenna mount140-cthat includes a compliant member405-acoupled between a first structure205-cand a second structure210-c, where the compliant member405-asupports a compressive preload of contact points of the planar coupling225-c. The compliant member405-amay be a spring or a compliant block, and in the example of antenna mount140-c, the compliant member405-amay be under a compressive preload. The compressive preload of the compliant member405-amay be reacted by the compliant coupling230-c, where the compliant coupling230-cmay be under a tensile preload, or may have a compressive preload (e.g., due to supporting the mass of the antenna assembly110-eand components of the antenna mount140-cagainst gravity) reduced. Antenna mount140-cillustrates an example where a compliant member405is coupled between different components than a planar coupling225, while still supporting a compressive preload of the planar coupling225. In the example of antenna mount140-c, the compliant member405-amay be included in both an in-plane sprung mass290-cand a linearly sprung mass295-c. Although only one compliant member405-ais illustrated, various examples may include more than one compliant member405-a.

FIG.4Billustrates an antenna mount140-dthat includes a compliant member405-bcoupled between a second structure210-dand a third structure215-d, where the compliant member405-bsupports a compressive preload of contact points of the planar coupling225-d. The compliant member405-bmay be a spring or a compliant block, and in the example of antenna mount140-d, the compliant member405-bmay be under a tensile preload. The tensile preload of the compliant member405-bmay be entirely reacted by the contact points of the planar coupling225-d. Antenna mount140-dillustrates an example where a compliant member405is coupled between the same components as a planar coupling225. Although the compliant member405-bis shown as a separate component from the planar coupling225-d, in some examples the compliant coupling405-band the planar coupling225-dmay be integrated in the same component. In the example of antenna mount140-d, at least a portion of the compliant member405-bmay be included the in-plane sprung mass290-d, but the compliant member405-bmay be excluded from the linearly sprung mass295-d. Although only one compliant member405-bis illustrated, various examples may include more than one compliant member405-b, or may be combined with a compliant member405-acoupled between the first structure205-dand the second structure210-d. Although only the configurations of antenna mounts140-cand140-dare illustrated for the sake of brevity, compliant members405may be arranged in other configurations for providing the described compressive preload of a planar coupling225. Furthermore, in some examples compliant members405may be designed such that such that a compressive preload is relieved under some circumstances (e.g., extreme vibrations, extreme shock loading, etc.) such that contact points of a planar coupling225would temporarily lose contact (e.g., permitting a temporary relative displacement between a second structure210and a third structure215in a direction non-parallel with a plane associated with the planar coupling225).

FIGS.5A-5Dshow diagrams of mobile communication systems500-athrough500-dincluding different arrangements of antenna mounts140for suppressing rotational movement between an antenna assembly110and a vehicle105, in accordance with aspects of the present disclosure. Antenna mounts140may include a first structure205, a second structure210, a third structure215, a linear coupling220, a planar coupling225, and a compliant coupling230, each of which may be examples of one or more aspects of the respective components described with reference toFIGS.2-4B. The arrangements of mobile communication systems500-athrough500-dshow examples of antenna mounts140where a second structure210is mechanically coupled between a first structure205and a third structure215, but is not spatially located between the first structure205and the third structure215.

FIG.5Aillustrates an example of an antenna mount140-e, where the first structure205-eis coupled with the vehicle105-g, and the third structure215-eis coupled with the antenna assembly110-g. As shown, the antenna mount140-emay include a linear coupling220-ebetween the first structure205-eand the second structure210-e, a planar coupling225-ebetween the second structure210-eand the third structure215-e, and a compliant coupling230-ebetween the first structure205-eand the third structure215-e. For antenna mount140-e, the second structure210-eis arranged over both the first structure205-eand the third structure215-esuch that the third structure215-eand/or the antenna assembly110-gpasses through or around the second structure210-e. For example, as shown, the second structure210-emay include a cutout where the third structure215-epasses through the second structure210-e. Additionally or alternatively, the third structure215-eand/or antenna assembly110-gmay pass around the second structure210-e(e.g., without a hole or cutout in the second structure210-e).

FIG.5Billustrates an example of an antenna mount140-f, where the first structure205-fis coupled with the antenna assembly110-h, and the third structure215-fis coupled with the vehicle105-h. As shown, the antenna mount140-fmay include a linear coupling220-fbetween the first structure205-fand the second structure210-f, a planar coupling225-fbetween the second structure210-fand the third structure215-f, and a compliant coupling230-fbetween the first structure205-fand the third structure215-f. For antenna mount140-f, the second structure210-fis arranged over both the first structure205-fand the third structure215-fsuch that the first structure205-fand/or the antenna assembly110-hpasses through or around the second structure210-f. For example, as shown, the second structure210-fmay include a cutout where the first structure205-fpasses through the second structure210-f. Additionally or alternatively, the first structure205-fand/or antenna assembly110-hmay pass around the second structure210-f(e.g., without a hole or cutout in the second structure210-f).

FIG.5Cillustrates an example of an antenna mount140-g, where the first structure205-gis coupled with the vehicle105-i, and the third structure215-gis coupled with the antenna assembly110-i. As shown, the antenna mount140-gmay include a linear coupling220-gbetween the first structure205-gand the second structure210-g, a planar coupling225-gbetween the second structure210-gand the third structure215-g, and a compliant coupling230-gbetween the first structure205-gand the third structure215-g. For antenna mount140-g, the second structure210-gis arranged below both the first structure205-gand the third structure215-gsuch that the first structure205-gand/or the vehicle105-ipasses through or around the second structure210-g. For example, as shown, the second structure210-gmay include a cutout where the first structure205-gpasses through the second structure210-g. Additionally or alternatively, the first structure205-gand/or vehicle105-imay pass around the second structure210-g(e.g., without a hole or cutout in the second structure210-g).

FIG.5Dillustrates an example of an antenna mount140-h, where the first structure205-his coupled with the antenna assembly110-j, and the third structure215-his coupled with the vehicle105-j. As shown, the antenna mount140-hmay include a linear coupling220-hbetween the first structure205-hand the second structure210-h, a planar coupling225-hbetween the second structure210-hand the third structure215-h, and a compliant coupling230-hbetween the first structure205-hand the third structure215-h. For antenna mount140-h, the second structure210-his arranged below both the first structure205-hand the third structure215-hsuch that the third structure215-hand/or the vehicle105-jpasses through or around the second structure210-h. For example, as shown, the second structure210-hmay include a cutout where the third structure215-hpasses through the second structure210-h. Additionally or alternatively, the third structure215-hand/or vehicle105-jmay pass around the second structure210-h(e.g., without a hole or cutout in the second structure210-h).

FIGS.6A-6Cillustrate an example of an antenna mount140-ifor suppressing rotational movement between an antenna assembly110and a vehicle105, in accordance with various aspects of the present disclosure.FIG.6Aillustrates a perspective view of the antenna mount140-i,FIG.6Billustrates a top-down view of the antenna mount140-i, andFIG.6Cillustrates a side view of the antenna mount140-i. The antenna mount140-imay include a first structure205-i, a second structure210-i, and a third structure215-i, each of which may be examples of one or more aspects of the respective components described with reference toFIGS.2-5D. The antenna mount140-imay follow the arrangement of the antenna mount140-adescribed with reference toFIG.2. In other words, the first structure205-imay be coupled with, or be a portion of a vehicle105, and the third structure215-imay be coupled with, or be a portion of an antenna assembly110(not shown). The second structure210-iis an intermediate structure coupled between the first structure205-iand the third structure215-i.

Antenna mount140-iincludes an example of a linear coupling220-icomprising four linear bearings610aligned along a linear direction (e.g., direction601), which may be aligned with a vertical direction of a vehicle105and/or aligned perpendicular to an elevation reference plane282of an antenna assembly110. The four linear bearings610of the linear coupling220-iare arranged such that they constrain relative movement between the first structure205-iand the second structure210-ito be along the direction601. Here, each of the linear bearings610are shown with pillow block bearing assemblies coupled to the second structure210-iand cylindrical shafts coupled to the first structure205-i, and disposed through a corresponding pillow block bearing.

Antenna mount140-ialso includes an example of a planar coupling225-ithat suppresses rotational movement of the third structure215-irelative to the second structure210-iabout axes parallel to a plane associated with the planar coupling225-i. For example, the plane associated with the planar coupling may be parallel to directions602and603, and thus may suppress rotations about axes within a plane defined by direction602and direction603. The planar coupling225-imay permit relative translations between the second structure210-iand the third structure215-iwithin a plane defined by directions602and603, and in some examples may also permit relative rotations between the second structure210-iand the third structure215-iabout an axis that is perpendicular to directions602and603(e.g., in direction604). In some examples directions602and/or603may be aligned with a roll axis of a vehicle105or a pitch axis of a vehicle105, and may be perpendicular to direction601. Thus, in some examples the planar coupling225-imay permit relative rotations between the second structure210-iand the third structure215-iabout the direction601.

Antenna mount140-ialso includes an example of a compliant coupling230-icomprising four wire rope isolators620that provide a centering force between the first structure205-iand the third structure215-i. The wire rope isolators620may be symmetrically arranged about axis605, which may represent a center of stiffness with respect to the plane associated with the planar coupling210-i. In some examples, an in-plane sprung mass290including an antenna assembly110mounted to the antenna mount140-imay have a center of gravity located at a point coincident with the axis605. In this way, translational loads and/or accelerations from a vehicle105may not be converted into rotations about an axis perpendicular to the plane associated with the planar coupling210-i(e.g., rotations in direction604).

FIG.7illustrates a sectional view700showing portions of an antenna mount140-jfor suppressing rotational movement between an antenna assembly110and a vehicle105, in accordance with aspects of the present disclosure. The antenna mount140-jmay include a first structure205-j, a second structure210-j, and a third structure215-j, each of which may be examples of one or more aspects of the respective components described with reference toFIGS.2-6C. The antenna mount140-jmay follow the arrangement of the antenna mount140-adescribed with reference toFIG.2. In other words, the first structure205-jmay be coupled with, or be a portion of a vehicle105, and the third structure215-jmay be coupled with, or be a portion of an antenna assembly110. The second structure210-jis an intermediate structure coupled between the first structure205-iand the third structure215-i. In section view700, portions of the third structure215-jare hidden so that internal components can be shown. For example, section view700shows aspects of a planar coupling225-j, having contact plates710and compliant members405-c.

Antenna mount140-iincludes an example of a linear coupling220-jcomprising a number of linear bearings610-aaligned along a linear direction, which may be aligned with a vertical direction of a vehicle105and/or aligned perpendicular to an elevation reference plane282of an antenna assembly110. Here, each of the linear bearings610-aare shown with track bearing assemblies coupled to the second structure210-jand non-cylindrical linear tracks coupled to the first structure205-jand disposed through a corresponding track bearing assembly. Antenna mount140-jalso includes an example of a compliant coupling230-jcomprising a number of wire rope isolators620-athat provide a centering force between the first structure205-jand the third structure215-j.

Planar coupling225-jmay be configured to suppress rotational movement of the third structure215-jrelative to the second structure210-jabout axes parallel to a plane associated with the planar coupling225-i. The planar coupling225-jincludes compliant members405-aand contact points having a contact plate710coupled to the third structure215-jand spherical transfer bearings715coupled to the second structure210-j. The combination of the contact plates710and the spherical transfer bearings715allows rolling contact between the second structure210-iand the third structure215. The rolling surface of each of the contact plates710may be parallel to each other, thereby defining the plane associated with the planar coupling225-j. In the example of antenna mount140-j, the rolling surface of each of the contact plates710is in the same plane.

The contact between the spherical transfer bearings715and the contact plates710may be associated with a compressive preload to maintain contact between the spherical transfer bearings715and the respective contact plates710through various system movements or vibrations, which may be provided by the compliant members405-a(e.g., coil springs), which may be examples of compliant members405described with reference toFIG.4. As the compliant members405-aare coupled between the second structure210-jand the third structure215-j, the compliant members405-amay be under a tensile preload to support the compressive preload between the spherical transfer bearings715and the contact plates710(e.g., the compressive preload of the planar coupling225-j). The compliant members405-amay be configured to maintain the compressive preload of the planar coupling225-jthrough various relative movements between the second structure210-jand third structure215-j, and in some cases the compliant members405-amay also provide a centering force between the second structure210-jand the third structure215-j.

The detailed description set forth above in connection with the appended drawings describes exemplary embodiments and does not represent the only embodiments that may be implemented or that are within the scope of the claims. The term “example” used throughout this description means “serving as an example, instance, or illustration,” and not “preferred” or “advantageous over other embodiments.” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described embodiments.

The foregoing description and claims may refer to elements or features as being “connected” or “coupled” together. As used herein, unless expressly stated otherwise, “connected” means that one element/feature is directly or indirectly connected to another element/feature. Likewise, unless expressly stated otherwise, “coupled” means that one element/feature is directly or indirectly coupled with another element/feature.

Thus, although the various schematics shown in the Figures depict example arrangements of elements and components, additional intervening elements, devices, features, or components may be present in an actual embodiment (assuming that the functionality of the depicted circuits is not adversely affected).

Information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The functions described herein may be implemented in various ways, with different materials, features, shapes, sizes, or the like. Other examples and implementations are within the scope of the disclosure and appended claims. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Also, as used herein, including in the claims, “or” as used in a list of items (for example, a list of items prefaced by a phrase such as “at least one of” or “one or more of”) indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

The previous description of the disclosure is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.