Torso damping technique

Abstract

Methods, systems, and devices for body attenuation techniques are described. An antenna system may include one or more antennas and may have a field of view and operating frequency. An antenna system may be associated with a radome configured to enclose the antenna system and a radome mounting structure configured to couple the radome to the outer surface of the vehicle. One or more signal attenuation features may be mounted below the field of view of the antenna system (e.g., on the radome mounting structure). One or more signal attenuation features may be configured to attenuate the electromagnetic wave transmission of the antenna system at an operating frequency. Such attenuation features may include a conductive structure containing a certain amount of conductive pillars, a sawtooth structure containing a certain amount of conductive sawtooths, a composite conductive structure, a conductive coating, an arrangement of segmented conductive rings, or a combination thereof.

Description

Technical Field

[0001] Cross-reference This patent application claims the benefit of U.S. Provisional Patent Application No. 63 / 498,193, filed Apr. 25, 2023, by Runyon et al., entitled “FUSELAGE ATTENUATION TECHNIQUES,” which is assigned to the assignee of this application and is hereby expressly incorporated by reference in its entirety.

[0002] The following generally relates to a communication system, including fuselage attenuation techniques.

Background Art

[0003] A communication system may include an antenna configured to communicate information by wireless signaling. The wireless signaling may be implemented using a wireless spectrum supported by the communication system. The antenna may communicate using the wireless spectrum with one or more other devices of the communication system. However, in the case of a mobile application where the antenna is mounted on a vehicle (e.g., an aircraft), the antenna may transmit signals while moving near other devices that do not intend to receive the communication from the antenna or near the coverage area. In some examples, the transmission of wireless signaling using similar frequencies may interfere with the communication of another device or communication system.

Summary of the Invention

[0004] The techniques described relate to improved methods, systems, devices, and apparatus for supporting vehicle fuselage attenuation. Vehicles such as airplanes may include antennas capable of operating to communicate with other devices in a communication system (e.g., communication satellites or other overhead devices). For example, an antenna may support the transmission and reception of information via radio signaling communicated using the radio spectrum (e.g., within an operating frequency band that can correspond to a range of frequencies). In some cases, similar (e.g., at least partially overlapping) operating frequencies of the radio spectrum may be used by other devices (e.g., ground devices, low-altitude devices) or other communication systems for communicating radio signaling, such that the antenna may share at least a portion of the radio spectrum with the other devices or communication systems. In mobile applications, for example, an antenna may be associated with (e.g., mounted on) a vehicle that can move near the coverage area of ​​the other communication system. For example, an antenna may be mounted on an aircraft that can travel through or above the coverage area of ​​the other communication system. However, because antennas and other communication devices may share similar radio spectra, transmissions from an antenna can interfere with other communication devices when the antenna moves near the coverage area of ​​another communication system. For example, when an antenna is above the coverage area of ​​another communication system, radio signaling transmitted from the antenna may interfere with radio signaling transmitted by that other communication system.

[0005] In some cases, the physical positioning of an antenna relative to a vehicle can be associated with generating interference with other communication systems. For example, an antenna may be mounted along the top surface of an aircraft and configured to communicate radio signaling in an area defined by an angle with respect to the aircraft (e.g., a field of view). The antenna may be configured to communicate via electromagnetic wave transmission within the area, which may include signaling according to a direction of peak gain that is generally above or to the side of the aircraft (e.g., bore-right direction). The area in which an antenna is configured to communicate radio signaling is "line of sight (LOS)" satellite communication where two stations (e.g., an antenna and a satellite) have a direct signal path between the stations. However, in some cases, electromagnetic wave transmission from an antenna may propagate outside the area (e.g., below the area), and as a result, electromagnetic wave transmission outside the area (e.g., outside a certain angle with respect to the aircraft, below a certain angle with respect to the aircraft) may cause interference with other communication systems communicating via similar radio spectrum (e.g., systems or devices at lower altitudes or elevation angles). In some such cases, the aircraft fuselage can at least partially attenuate electromagnetic wave transmission along one or more directions below the fuselage. However, the degree of fuselage attenuation can vary depending on the antenna operating frequency (e.g., one or more frequencies in the operating frequency band), the size and shape of the fuselage, as well as other features of the aircraft such as the wings and tail, and some portion of the electromagnetic wave transmission may still cause interference with other communication systems.

[0006] As illustrated herein, an antenna signal attenuator may be mounted on a vehicle (e.g., on the fuselage) to reduce signal propagation that may interfere with other devices or other communication systems. For example, an antenna signal attenuator may be mounted on a vehicle (e.g., on the fuselage) to increase signal attenuation in the area below LOS communication to a target satellite or other target device. The antenna signal attenuator may include a mounting structure, such as a radome mounting structure or fairing, configured to couple with the surface of the vehicle via an interface of the mounting structure. In some implementations, the mounting structure may be configured to mount above the vehicle (e.g., along the top surface of the vehicle). In some implementations, the antenna system may be mounted on the vehicle within an opening in the mounting structure, which may include mounting the antenna system directly to the vehicle. In some other implementations, the antenna system may be mounted to the mounting structure via another interface of the mounting structure. An antenna signal attenuator may include one or more signal attenuation features mounted on (e.g., coupled to, attached to, fastened to, or otherwise) a mounting structure and configured to attenuate the electromagnetic wave transmission of the antenna system (e.g., within the operating frequency band of the antenna system, outside the field of view of the antenna system). Attenuation features such as metamaterials and other attenuation features may interfere with, absorb, redirect (e.g., reflect, absorb, and re-emit) or modify (e.g., interfere with coherence, depolarize) electromagnetic wave transmissions propagating outside the field of view of the antenna system relative to the vehicle, thereby reducing interference caused by electromagnetic wave transmissions outside the field of view. In some examples, attenuation features may be configured to restrict electromagnetic wave transmissions propagating at a certain angle downward relative to the vehicle (e.g., the boundary of a shadow where direct line-of-sight radiation does not occur without an obstruction), which may prevent electromagnetic wave transmissions from interfering with radio signaling communicated by other devices (e.g., ground-based devices) that may use a similar radio spectrum.

[0007] The described examples of attenuation features may include conductive structures, composite conductive structures, sawtooth structures, resonant conductive structures, segmented conductive rings, conductive or partially conductive (e.g., resistive type) coatings applied to one or more surfaces of a mounting structure, or combinations thereof. For example, a conductive structure mounted for signal attenuation may include conductive pillars (e.g., prism pillars, pyramidal pillars) which may be arranged in a pattern on the upper surface of a mounting structure. A composite conductive structure mounted for signal attenuation may include a pattern of conductive structures formed of one or more dielectric layers (e.g., according to printed circuit board (PCB) techniques or other additive or subtractive techniques) which may be arranged on the upper surface of a mounting structure. A sawtooth structure mounted for signal attenuation may include conductive sawtooth bodies arranged at one or more angles (e.g., with respect to the upper surface of a radome mounting structure) which may be mounted on the upper surface of a mounting structure. Divided conductive rings implemented for signal attenuation may be positioned on the side of a mounting structure and may be configured to disrupt signal coherence, depolarize electromagnetic wave transmission, or both by rotating the individual conductive rings relative to each other within the group of rings. Conductive coatings or partially conductive coatings implemented for signal attenuation may be applied to the side of the composite material of the mounting structure. Implementing attenuation features on vehicle mounting structures such as radome mounting structures can attenuate electromagnetic wave transmission in antenna systems, thereby reducing interference to other devices or communication systems.

[0008] Further scope of applicability of the described methods and systems will become apparent from the embodiments for carrying out the invention, the claims, and the drawings below. Since various changes and modifications within the scope of the description will be apparent to those skilled in the art, the embodiments for carrying out the invention and specific examples are given merely as illustrative examples. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 shows an example of a satellite communication system that supports fuselage attenuation techniques, as described herein. [Figure 2A] Figure 2A shows an embodiment of a system supporting the fuselage damping technique, as illustrated in the examples described herein. [Figure 2B] Figure 2B shows an embodiment of a system supporting the fuselage damping technique, as illustrated in the examples described herein. [Figure 2C] Figure 2C shows an embodiment of a system supporting the fuselage damping technique, as illustrated in the examples described herein. [Figure 3A] Figure 3A shows an example of a system supporting the fuselage damping technique, as described herein. [Figure 3B] Figure 3B shows an example of a system supporting the fuselage damping technique, as described herein. [Figure 3C] Figure 3C shows an example of a system supporting the fuselage damping technique, as described herein. [Figure 4A] Figure 4A shows an example of a composite conductor structure that supports the body damping technique, as described herein. [Figure 4B] Figure 4B shows an example of a composite conductor structure that supports the body damping technique, as described herein. [Figure 5] Figure 5 shows an example of a system supporting the fuselage damping technique, as described herein. [Figure 6] Figure 6 shows an example of a system supporting the fuselage damping technique, as described herein. [Figure 7] Figure 7 shows an example of a system supporting the fuselage damping technique, as described herein. [Modes for carrying out the invention]

[0010] The techniques described relate to improved methods, systems, devices, and apparatus for supporting vehicle fuselage attenuation. Vehicles such as airplanes may include antennas capable of operating to communicate with other devices in a communication system (e.g., communication satellites or other overhead devices). For example, an antenna may support the transmission and reception of information via radio signaling communicated using the radio spectrum (e.g., within an operating frequency band that can correspond to a range of frequencies). In some cases, similar (e.g., at least partially overlapping) operating frequencies of the radio spectrum may be used by other devices (e.g., ground devices, low-altitude devices) or other communication systems for communicating radio signaling, such that the antenna may share at least a portion of the radio spectrum with the other devices or communication systems. In mobile applications, for example, an antenna may be associated with (e.g., mounted on) a vehicle that can move near the coverage area of ​​the other communication system. For example, an antenna may be mounted on an aircraft that can travel through or above the coverage area of ​​the other communication system. However, because antennas and other communication devices may share similar radio spectra, transmissions from an antenna can interfere with other communication devices when the antenna moves near the coverage area of ​​another communication system. For example, when an antenna is above the coverage area of ​​another communication system, radio signaling transmitted from the antenna may interfere with radio signaling transmitted by that other communication system.

[0011] In some cases, the physical positioning of an antenna relative to a vehicle can be associated with generating interference with other communication systems. For example, an antenna may be mounted along the top surface of an aircraft and configured to communicate radio signaling in an area defined by an angle with respect to the aircraft (e.g., a field of view). The antenna may be configured to communicate via electromagnetic wave transmission within the area, which may include signaling according to a direction of peak gain that is generally above or to the side of the aircraft (e.g., bore-right direction). The area in which an antenna is configured to communicate radio signaling is "line of sight (LOS)" satellite communication where two stations (e.g., an antenna and a satellite) have a direct signal path between the stations. However, in some cases, electromagnetic wave transmission from an antenna may propagate outside the area (e.g., below the area), and as a result, electromagnetic wave transmission outside the area (e.g., outside a certain angle with respect to the aircraft, below a certain angle with respect to the aircraft) may cause interference with other communication systems communicating via similar radio spectrum (e.g., systems or devices at lower altitudes or elevation angles). In some such cases, the aircraft fuselage can at least partially attenuate electromagnetic wave transmission along one or more directions below the fuselage. However, the degree of fuselage attenuation can vary depending on the antenna operating frequency (e.g., one or more frequencies in the operating frequency band), the size and shape of the fuselage, as well as other features of the aircraft such as the wings and tail, and some portion of the electromagnetic wave transmission may still cause interference with other communication systems.

[0012] As illustrated herein, an antenna signal attenuator may be mounted on a vehicle (e.g., on the fuselage) to reduce signal propagation that may interfere with other devices or other communication systems. For example, an antenna signal attenuator may be mounted on a vehicle (e.g., on the fuselage) to increase signal attenuation in the area below LOS communication to a target satellite or other target device. The antenna signal attenuator may include a mounting structure, such as a radome mounting structure or fairing, configured to couple with the surface of the vehicle via an interface of the mounting structure. In some implementations, the mounting structure may be configured to mount above the vehicle (e.g., along the top surface of the vehicle). In some implementations, the antenna system may be mounted on the vehicle within an opening in the mounting structure, which may include mounting the antenna system directly to the vehicle. In some other implementations, the antenna system may be mounted to the mounting structure via another interface of the mounting structure. An antenna signal attenuator may include one or more signal attenuation features mounted on (e.g., coupled to, attached to, fastened to, or otherwise) a mounting structure and configured to attenuate the electromagnetic wave transmission of the antenna system (e.g., within the operating frequency band of the antenna system, outside the field of view of the antenna system). Attenuation features such as metamaterials and other attenuation features may interfere with, absorb, redirect (e.g., reflect, absorb, and re-emit) or modify (e.g., interfere with coherence, depolarize) electromagnetic wave transmissions propagating outside the field of view of the antenna system relative to the vehicle, thereby reducing interference caused by electromagnetic wave transmissions outside the field of view. In some examples, attenuation features may be configured to restrict electromagnetic wave transmissions propagating at a certain angle downward relative to the vehicle (e.g., the boundary of a shadow where direct line-of-sight radiation does not occur without an obstruction), which may prevent electromagnetic wave transmissions from interfering with radio signaling communicated by other devices (e.g., ground-based devices) that may use a similar radio spectrum.

[0013] The described examples of attenuation features may include conductive structures, composite conductive structures, sawtooth structures, resonant conductive structures, segmented conductive rings, conductive or partially conductive (e.g., resistive type) coatings applied to one or more surfaces of a mounting structure, or combinations thereof. For example, a conductive structure mounted for signal attenuation may include conductive pillars (e.g., prism pillars, pyramidal pillars) which may be arranged in a pattern on the upper surface of a mounting structure. A composite conductive structure mounted for signal attenuation may include a pattern of conductive structures formed of one or more dielectric layers (e.g., according to printed circuit board (PCB) techniques or other additive or subtractive techniques) which may be arranged on the upper surface of a mounting structure. A sawtooth structure mounted for signal attenuation may include conductive sawtooth bodies arranged at one or more angles (e.g., with respect to the upper surface of a radome mounting structure) which may be mounted on the upper surface of a mounting structure. Divided conductive rings implemented for signal attenuation may be positioned on the side of a mounting structure and may be configured to disrupt signal coherence, depolarize electromagnetic wave transmission, or both by rotating the individual conductive rings relative to each other within the group of rings. Conductive coatings or partially conductive coatings implemented for signal attenuation may be applied to the side of the composite material of the mounting structure. Implementing attenuation features on vehicle mounting structures such as radome mounting structures can attenuate electromagnetic wave transmission in antenna systems, thereby reducing interference to other devices or communication systems.

[0014] The embodiments of the examples described herein are first described in the context of satellite communication systems. The embodiments of the examples described herein are further illustrated and described by reference to systems and attenuation features related to fuselage attenuation techniques.

[0015] Figure 1 shows a diagram of a communication system 100 that may implement one or more fuselage attenuation techniques as described herein. The communication system 100 may include a first satellite 105-a, a first gateway 115-a, a first gateway antenna system 110-a, and a vehicle 130 (e.g., an aircraft). The first gateway 115-a may communicate with at least a first network 120-a. The communication system 100 may provide one-way or two-way communication between the vehicle 130 and the first network 120-a through at least the first satellite 105-a and the first gateway 115-a. In some examples, the communication system 100 may include a second satellite 105-b, a second gateway 115-b, and a second gateway antenna system 110-b. The second gateway 115-b may communicate with at least a second network 120-b. The communication system 100 can provide one-way or two-way communication between the vehicle 130 and the second network 120-b via at least a second satellite 105-b and a second gateway 115-b. In some examples, networks 120-a and 120-b may be combined or be the same network, among other implementations. Although two satellites 105 are illustrated, the communication system 100 may be implemented with any number of one or more satellites 105 supporting communication with any number of one or more networks 120.

[0016] Satellite 105 can be any suitable type of communications satellite. In some examples, one or more satellites 105 may be in geostationary orbit. In other examples, any suitable orbit (e.g., non-geostationary orbit (NGSO), low Earth orbit (LEO), medium Earth orbit (MEO)) may be used for satellite 105. Satellite 105 may be a multibeam satellite (e.g., using one or more multibeam reflector antennas, multibeam fixed arrays, or phased arrays) configured to provide service to multiple service beam coverage areas in a geographical service area. The first satellite 105-a and the second satellite 105-b may support communications services in non-overlapping, partially overlapping, or fully overlapping coverage areas.

[0017] The first gateway antenna system 110-a may be unidirectional or bidirectional and may be designed with appropriate transmission power and reception sensitivity for communicating with the first satellite 105-a. The first satellite 105-a may communicate with the first gateway antenna system 110-a by transmitting or receiving signals 160-a (e.g., beams, beam signals, beamformed beams of one or more phased arrays). The first gateway 115-a may transmit and receive signals to and from the first satellite 105-a using the first gateway antenna system 110-a. The first gateway 115-a may be connected to the first network 120-a. The first network 120-a may include a local area network (LAN), a metropolitan area network (MAN), a wide area network (WAN), or any other suitable public or private network and may be connected to other communication networks such as the Internet, telephone networks (e.g., public switched telephone networks (PSTN)).

[0018] An example of the communication system 100 may include components of the communication system 100 that are unique to the second satellite 105-b or shared with other satellites 105 (e.g., the first satellite 105-a). For example, the second gateway antenna system 110-b may be capable of one-way or two-way communication and may be designed with appropriate transmission power and reception sensitivity to reliably communicate with the second satellite 105-b. The second satellite 105-b may communicate with the second gateway antenna system 110-b by transmitting and receiving signals 160-b. The second gateway 115-b may use the second gateway antenna system 110-b to transmit signals to the second satellite 105-b and receive signals from the second satellite 105-b. The second gateway 115-b may be connected to the second network 120-b. The second network 120-b may include a local area network (LAN), a metropolitan area network (MAN), a wide area network (WAN), or any other suitable public or private network and may be connected to other communication networks such as the Internet, a telephone network (e.g., a public switched telephone network (PSTN), etc.).

[0019] In various examples, the first network 120-a and the second network 120-b may be different networks, combined networks, or the same network 120. In various examples, the first gateway 115-a and the second gateway 115-b may be different gateways or the same gateway 115. In various examples, the first gateway antenna system 110-a and the second gateway antenna system 110-b may be different gateway antenna systems or the same gateway antenna system 110.

[0020] Vehicle 130 can employ a communication system that includes an antenna system 140. The antenna system 140 can include any number of one or more antennas 141. For example, as illustrated, the antenna system 140 can include a first antenna 141-a and a second antenna 141-b. In various examples, the antenna 141 can include a mirror-type antenna (e.g., having a reflector and at least one antenna element), an array antenna (e.g., an antenna having an array of a plurality of antenna elements), a phased array antenna (e.g., an antenna having an array of a plurality of antenna elements operable to form a beam along a beam-formed beam direction), or another type of antenna. In some examples, the antenna 141 can include a dual-polarization plane horn antenna array (e.g., including a phased array of antenna elements). In some examples, the first antenna 141-a and the second antenna 141-b can be the same type of antenna or different types of antennas. The antenna system 140 can be mounted on the outer surface 131 of the body of the vehicle 130 and can be located under a radome 145 (e.g., associated with a volume for the placement of the antenna system 140 and at least partially surrounding the antenna system 140).

[0021] In some implementations, the antenna system 140 may include a steering system 135 (e.g., a beam steering system) configured to point (e.g., steer, align, orient) the boresights 180 of the antenna system 140 (e.g., the direction of peak gain, the direction of highest transmission strength, the direction of highest reception sensitivity). In some examples, the steering system 135 may include a mechanical steering system (e.g., a positioning mechanism) configured to physically point one or more antennas 141 (e.g., an antenna aperture, each boresight 180 of one or more antennas 141) toward a target, such as aligning toward satellite 105 during operation (e.g., according to active mechanical tracking). In some examples, the mechanical steering system may include a system for physically controlling the orientation of one or more antennas 141 of the antenna system 140 about one or more axes (e.g., positioning axes, mechanical positioning axes), such as within the field of view of the antenna system 140. For example, the mechanical steering system may include components that can operate to control the azimuthal and elevation orientations of the antenna 141, among other orientations (e.g., with respect to the coordinate system of the vehicle 130). Additionally or alternatively, the steering system 135 may include an electronic steering system (e.g., a beamforming system) configured to electronically steer one or more beams (e.g., one or more transmission beams, one or more receiving beams) of one or more antennas 141 toward a target. For example, the electronic steering system may include a system for electronically steering the boresite 180 of the antenna system 140 based on adjusting the feed element signals of the array of antenna elements (e.g., by phase offset, by time offset, by amplitude offset) (e.g., in the absence of a mechanical steering system, in addition to a mechanical steering system).

[0022] In some examples, antenna 141 may operate in the International Telecommunication Union (ITU) Ku, K, or Ka band, for example, about 17–31 gigahertz (GHz) (e.g., operating frequency band). Additionally or alternatively, antenna 141 may operate in other frequency bands (e.g., other operating frequency bands), such as the C band, X band, S band, and L band. In various examples, the first antenna 141-a and the second antenna 141-b may be configured to operate in different frequency bands (e.g., so that the operating frequency of the antenna system 140 may include the operating frequencies of multiple antennas 141), or to operate in the same frequency band. For example, the first antenna 141-a may be configured to operate in the Ku band (e.g., to receive signals in the 10.95–12.75 GHz range and transmit signals in the 14.0–14.5 GHz range), and the second antenna 141-b may be configured to operate in the Ka band (e.g., to receive signals in the 17.7–21.2 GHz range and transmit signals in the 27.5–31.0 GHz range). In some examples, the first antenna 141-a and the second antenna 141-b may be configured with different dimensions or other characteristics that can be utilized in different communication situations, for example, the first antenna 141-a may be relatively smaller and have relatively lower transmission or reception directivity (e.g., relatively lower beam gain, relatively wider beam focus), and the second antenna 141-b may be relatively larger and have relatively higher transmission or reception directivity (e.g., relatively higher beam gain, relatively tighter beam focus).

[0023] In some examples, the first antenna 141-a may be associated with the first satellite 105-a, and the second antenna 141-b may be associated with the second satellite 105-b. During operation, the vehicle 130 may be in a location within the coverage area of ​​the first satellite 105-a, within the coverage area of ​​the second satellite 105-b, or both, and in some examples, communication with either the first antenna 141-a or the second antenna 141-b may be selected based at least partially on the location of the vehicle 130. For example, in a first operating mode, while the vehicle 130 is located within the coverage area of ​​the first satellite 105-a, the vehicle 130 may use the first antenna 141-a of the antenna system 140 to communicate with the first satellite 105-a via a signal 151 (e.g., beam, beam signal, beamformed beam). In this first operating mode, the second antenna 141-b can be inactive or idle without maintaining a communication link with satellite 105. In some examples, for at least a portion of the first operating mode, the second antenna 141-b may be physically idle such that the operation of a shared drive element (e.g., a drive element common to both the first antenna 141-a and the second antenna 141-b) does not activate the second antenna 141-b.

[0024] In the second operating mode, while the vehicle 130 is located within the coverage area of ​​the second satellite 105-b, the vehicle 130 can communicate with the second satellite 105-b via signals 152-b (e.g., beam, beam signal, beamformed beam) using the second antenna 141-b of the antenna system 140. The second mode can be selected, for example, in response to the vehicle 130 entering the coverage area of ​​the second satellite 105-b, leaving the coverage area of ​​the first satellite 105-a, or both. In the second operating mode, the first antenna 141-a can be inactive or idle without maintaining a communication link with satellite 105. In some examples, for at least a portion of the second operating mode, the first antenna 141-a may be physically idle so that the operation of a shared drive element does not activate the first antenna 141-a. In an example where vehicle 130 is located within the overlapping coverage area of ​​both the first satellite 105-a and the second satellite 105-b, the second mode can be selected based on other factors such as network availability, communication capability, communication cost, signal strength, signal quality, or other parameters, or combinations of parameters.

[0025] In some other examples, both the first antenna 141-a and the second antenna 141-b can be associated with the first satellite 105-a (for example, they can support communication with the first satellite 105-a). In the first operating mode, the vehicle 130 can communicate with the first satellite 105-a via signal 151 using the first antenna 141-a, and in an alternative example of the second operating mode, the vehicle 130 can communicate with the first satellite 105-a via signal 152-a using the second antenna 141-b. The alternative example of the second mode can be selected, for example, in the event of an error, failure, or degradation of the first antenna 141-a, in which case the second antenna 141-b can provide backup communication. Additionally, or alternatively, an alternative example of the second mode may be to select to change from a communication protocol associated with a first operating frequency (e.g., a first operating frequency band) or a first antenna 141-a to a communication protocol associated with a second operating frequency (e.g., a second operating frequency band) or a second antenna 141-b. Additionally, or alternatively, to support communication under various circumstances, the antenna system 140 may be configured to select either the first antenna 141-a or the second antenna 141-b based on other criteria such as size or positional limitations of one or both of the first antenna 141-a or the second antenna 141-b, or antenna or beam characteristics of one or both of the first antenna 141-a or the second antenna 141-b, or a combination thereof.

[0026] In some examples, the vehicle 130's communication system can provide communication services for communication devices within the vehicle 130 via a modem (not shown). The communication devices may use the modem to connect to and access at least one of the first network 120-a or the second network 120-b via the antenna system 140. For example, a mobile device may communicate with at least one of the first network 120-a or the second network 120-b via a network connection to a modem, which may be wired or wireless. Wireless connectivity may be, for example, wireless local area network (WLAN) technology such as IEEE 802.11 (Wi-Fi) or other wireless communication technologies.

[0027] In some cases, electromagnetic wave transmission from one or more antennas 141 of the antenna system 140 may cause interference to other devices that may be operating in the same or different communication systems as the antenna system 140. For example, an antenna system 140 such as an aerial mobile earth station (e.g., ESIM) may be designed to comply with power flux density (PFD) limits, such as those on the ground. The purpose of such limits may be to ensure that an antenna system 140 such as an ESIM does not interfere with ground devices or communication systems that may be using the same spectrum.

[0028] As illustrated by View 170 (for example, a simplified cross-sectional view of an antenna system 140 mounted on a vehicle 130), the antenna system 140 may be mounted on the upper part of the vehicle 130, such as the upper part of an aircraft fuselage (for example, along the upper surface of the vehicle 130, generally along the positive z-direction, along the surface or edge of a mounting portion of surface 131). View 170 illustrates different regions of signaling for the vehicle 130 and the antenna system 140 (for example, region electromagnetic wave transmission of the antenna system 140) according to a coordinate system (for example, the coordinate system of the vehicle 130, where the x-direction may be aligned along the direction of travel of the vehicle 130, the y-direction may be aligned along the left-right direction of the vehicle, and the z-direction may be aligned along the up-down direction of the vehicle). For example, the antenna system 140 may be associated with a field of view 175 (e.g., a supported communication signaling direction), and the antenna system 140 may have a boresight 180 that is configurable within the field of view 175 (e.g., mechanically configurable, electronically configurable, or both, steerable). In the illustrated example of Figure 1, the field of view 175 is associated with a horizontal direction (e.g., a direction in the xy plane) and a direction having a component along at least the positive z direction (e.g., a direction relatively upward from the xy plane). However, in some other examples, the field of view 175 may be relatively wider (e.g., including at least several boresight directions that are relatively downward from the xy plane) or relatively narrower (e.g., omitting directions in the xy plane and omitting at least several relatively upward directions that are less than a threshold angle from the xy plane).

[0029] The modes of electromagnetic wave transmission and signal attenuation can be described with respect to the field of view 175. Although the field of view 175 is illustrated in the yz plane, it can be associated with azimuth (e.g., measured in the xy plane) and elevation (e.g., measured relative to the xy plane) so that the field of view 175 can refer to a three-dimensional region with respect to the vehicle 130. For example, region 171 may refer to a “visible region” associated with a line-of-sight view of electromagnetic wave transmission from the antenna system 140 (e.g., a direction of transmission that does not coincide with the body of the vehicle 130). In some examples, region 171 (e.g., in the yz plane) may correspond to an off-axis elevation angle of 23 degrees or less below with respect to the antenna 141 pointing along the y direction (e.g., towards the port or starboard side of the vehicle). In some examples, the body of the vehicle 130 (e.g., the fuselage of an aircraft) may block and attenuate at least some of the electromagnetic radiation outside (e.g., below) region 171. For example, region 173 may refer to a “deep shadow region,” and region 172 may refer to a “transition region” between region 171 and region 173. Some relatively weaker surface currents may exist below region 171 (e.g., within region 173, within region 172) (e.g., within the body of vehicle 130) and may be re-radiated (e.g., as “creeping waves”). In region 173, the attenuation effect may be dominated by the body of vehicle 130 (e.g., body attenuation, creeping waves). In region 172, region 171, or both, the attenuation effect may be dominated by one or more attenuation features, which may be coupled with a fairing or other mounting structure (e.g., a mounting structure). The embodiments of regions 171, 172, and 173 are illustrated and described with reference to the yz plane, but such regions may have different sizes in locations along the xz plane, among other orientations, such that regions 171, 172, and 173 may have irregular shapes (e.g., volumes) around the vehicle 130 and antenna system 140 (for example, due to the fuselage having a relatively elongated cross-section along the x direction).

[0030] As illustrated herein, an antenna signal attenuator may be mounted on a vehicle 130 (e.g., on the body of the vehicle 130, on the torso of the vehicle 130) to reduce signal propagation that may interfere with other devices or other communication systems (e.g., terrestrial communications). In some implementations, the antenna signal attenuator may include mounting structures such as a radome mounting structure (e.g., for mounting a radome 145 to the vehicle 130), a fairing (e.g., separate from the radome mounting structure), or other mounting structures configured to couple with the surface 131 of the vehicle 130 via an interface of the mounting structure. In some examples, the mounting structure may be mounted above the vehicle 130 (e.g., along the top surface of the vehicle 130, in the positive z direction). In some implementations, the antenna system 140 may be mounted on the vehicle 130 within an opening in the mounting structure (e.g., through an opening), which may include mounting the antenna system 140 directly to the vehicle 130. In some other examples, the antenna system 140 may be attached to the mounting structure via another interface of the mounting structure.

[0031] An antenna signal attenuator may, in some examples, include one or more attenuation features that can be mounted (e.g., coupled, attached, or fastened) to a mounting structure and configured to attenuate electromagnetic wave transmission of the antenna system 140 (e.g., within the operating frequency band of the antenna system 140, outside the field of view 175, within region 173, within regions 173 and 172, and within regions 171, 172, and 173), or otherwise configured to be mounted on the vehicle 130 to support the described techniques for signal attenuation. For example, the attenuation features may interfere with, absorb, redirect (e.g., reflect, absorb, and re-emit) or modify (e.g., interfere with coherence, depolarize) electromagnetic wave transmission propagating outside the field of view 175 of the antenna system 140 relative to the vehicle 130, thereby reducing interference caused by electromagnetic wave transmission outside the field of view 175. In some examples, the attenuation feature may be configured to limit electromagnetic wave transmissions propagating downward at a certain angle relative to the vehicle 130 (e.g., undesirable off-axis emissions, emissions downward at a certain angle of the field of view 175), which can prevent the electromagnetic wave transmissions from interfering with radio signaling communicated by other devices (e.g., ground-based devices) that may be using a similar radio spectrum. In some examples, the signal attenuation feature may be configured to attenuate electromagnetic wave transmissions from propagating downwards to the mounting structure, such as below the radome mounting structure, among other examples.

[0032] Figures 2A–2C illustrate embodiments of system 200 supporting fuselage attenuation techniques, as illustrated by the examples described herein. System 200 may be implemented within a communication system 100. For example, system 200 (e.g., attenuation feature unit 220) may be mounted on a vehicle 130, such as an aircraft. Embodiments of system 200 (e.g., system 200-a, system 200-b, system 200-c) may be illustrated with reference to an illustrated coordinate system, which may correspond to the coordinate system of the vehicle 130 (e.g., an aircraft). Figures 2A–2C illustrate system 200 from various trimetric views, with Figure 2A illustrating system 200-a with an additional detailed front view in the yz plane. The system 200 may include an antenna system 140 and one or more attenuation feature units 220 configured to attenuate electromagnetic wave transmission of the antenna system 140 (e.g., sidelobe transmission, transmission along one or more directions different from the target receiving device, emission along a direction different from the field of view 175, spurious emission), the one or more attenuation feature units 220 being able to mitigate interference to other devices or communication systems (e.g., below the vehicle 130 including the system 200).

[0033] The antenna system 140 may include one or more antennas 141 configured to communicate radio signaling (e.g., one or more reflector-type antennas, one or more array antennas, one or more phased array antennas, or a combination thereof, among other types or combinations of antennas). For example, the antenna system 140-a of system 200-a may include an antenna 141 (e.g., not shown, but could be a single antenna 141) having one or more antenna elements (e.g., arrays of antenna elements, phased arrays) that can be fixed to the coordinate system of the vehicle 130 including system 200-a (e.g., without steering system 135, without mechanical steering system), such as an antenna element that can be statically aligned along the z direction (e.g., for transmitting or receiving signals at least partially along the z direction, which may include electron beamforming of steering system 135 for signaling along boresight 180 in vector components of the x, y, or combination thereof). In the example of system 200-a, such an antenna 141 may be located inside the cover 225 (for example, it may be located inside the cover 225, enclosed within the cover 225, and located within the volume of the cover 225). In some other examples, the cover 225 may be omitted from antenna system 140-a.

[0034] In another example, the antenna system 140-b of system 200-b may include one or more antennas (e.g., two antennas 141), each of which may be associated with one or more antenna elements of an aperture 205 that can be physically oriented by a steering system 135 (e.g., a mechanical steering system, a positioning mechanism). For example, the steering system 135 may be operable to adjust the elevation and azimuth angles of each of the one or more apertures 205 (e.g., independently and simultaneously). In some examples, the steering system 135 may be configured to adjust the elevation orientation (e.g., elevation angle) of each aperture 205 by rotating it about an axis parallel to the xy plane, and to adjust the azimuth orientation (e.g., azimuth angle) by rotating the aperture 205 about an axis parallel to the z direction. In some examples, the aperture 205 may be associated with multiple antenna elements, and the steering system 135 may also include an electronic steering system (e.g., a beamforming system). Such techniques may be implemented in antenna systems 140-b with one or more antennas 141 (e.g., one or more apertures 205) of any quantity, where the antennas 141 (e.g., apertures 205) may be associated with a swept volume corresponding to the total volume occupied by the antennas 141 or apertures 205 in different orientations that can be driven by a mechanical part of a steering system 135. Thus, in these and other examples, the antenna system 140 may include a steering system 135 configured to steer the boresight 180 of the antenna system 140 within a field of view 175. In some examples, the antenna system 140-b may include a cover 225 on the antennas 141 (e.g., on the apertures 205, not shown, surrounding the swept volume of the antennas 141).

[0035] In these and other examples, system 200 may include a radome 145 associated with a volume for the arrangement of the antenna system 140 (e.g., for at least partially enclosing it). For example, as illustrated in Figure 2C, system 200-c may include a radome 145-a associated with a volume for the arrangement of antenna system 140-c (not shown), which may include an embodiment of antenna system 140-a, antenna system 140-b, or another type of antenna system 140. The radome 145-a may be associated with protecting antenna system 140-c (e.g., from debris, from wind), or facilitating airflow around antenna system 140-c (e.g., to reduce fuel consumption of vehicle 130), or both. Some antenna systems 140 may include one or more reflectors (e.g., of the reflector antenna 141, within the radome 145, of the radome 145), such as low, medium, or high profile reflector antenna configurations, or combinations thereof.

[0036] Antenna systems 140-a, 140-b, and 140-c may be operated to support communication with other devices in the communication system (e.g., satellite 105) by communicating (e.g., transmitting, receiving) electromagnetic signals, among other configurations of antenna system 140. Electromagnetic wave transmission may include electromagnetic waves according to one or more frequencies in the operating frequency band of each antenna system 140 (e.g., one or more antennas 141). In some cases, adjusting the orientation of aperture 205 or other steering (e.g., electronic steering using steering system 135, beamforming) may change the direction of transmission from aperture 205. For example, antenna 141 may be configured to transmit electromagnetic waves along boresight 180 (e.g., boresight direction, peak gain direction, maximum transmission strength direction) from aperture 205 (e.g., according to one or more frequencies of the operating frequency band) that propagate along one or more directions (e.g., direction associated with field of view 175, beam direction, beamforming beam direction) relative to the orientation of aperture 205. Thus, according to these and other examples, antenna system 140 of system 200 may have a field of view 175 for communicating electromagnetic signals that may be along various directions from antenna system 140, different from the direction toward vehicle 130 (e.g., toward the torso) to which antenna system 140 is mounted.

[0037] A system 200 including an antenna system 140 may be mounted on the fuselage of a vehicle 130 (e.g., an aircraft) such that one or more antennas 141 of the antenna system 140 may be configured to transmit electromagnetic wave transmissions in a defined area relative to the vehicle 130 (e.g., a field of view 175). For example, antenna system 140-a or antenna system 140-b may be mounted on the upper surface of the aircraft fuselage. In some such cases, the body of the vehicle 130 (e.g., the fuselage) may at least partially attenuate electromagnetic wave transmissions propagating downward at a certain angle relative to the antenna system 140. For example, the fuselage may at least partially block electromagnetic wave transmissions downward at a certain angle (e.g., within area 173, within the deep shadow area). However, the fuselage may not sufficiently attenuate electromagnetic wave transmissions above that angle (e.g., within area 171, within the visible line of sight area) or downward at an angle tangent to the outer surface of the fuselage (e.g., within area 172, within the transition area). In some implementations, electromagnetic wave transmission at a certain angle downward relative to the antenna system 140-a may include unwanted side lobes generated by one or more arrays of antenna elements (e.g., side lobes associated with beamforming of the transmission beam of a phased array), among other transmissions, which may adversely affect the communications of other devices or communication systems (e.g., terrestrial communication systems).

[0038] System 200 may also include a radome mounting structure 210 (e.g., mounting structure, fairing) which can be configured to be attached to the body of a vehicle (e.g., the exterior of a vehicle 130, the fuselage of an aircraft). The radome mounting structure may be formed from a variety of materials, including plastic materials, composite materials (e.g., glass fiber composite, carbon fiber composite), and other materials which may include inserts (e.g., screw-in inserts, load-bearing inserts) to support various mounting techniques. The radome mounting structure 210 may include a variety of structures configured to connect the radome 145 to the exterior of the vehicle 130. For example, the radome mounting structure 210 may include an interface 215 for connecting (e.g., mounting, fastening, bonding, sealing) the radome mounting structure 210 to the vehicle 130, and an interface 216 for connecting the radome 145 to the radome mounting structure 210. In some cases, the radome mounting structure 210 may also include an interface for connecting an antenna system 140 to the radome mounting structure 210. For example, the radome mounting structure 210 may be connected to the fuselage via interface 215, and the antenna system 140 may be connected to the radome mounting structure 210 so that the antenna system 140 is connected to the fuselage via the radome mounting structure 210. In some other examples, the antenna system 140 may be coupled to the aircraft within an opening 211 of the radome mounting structure 210 (for example, as illustrated in system 200-b of Figure 2B) so that the antenna system 140 can be mounted directly to the aircraft. For example, the antenna system 140 may include an interface for coupling the antenna system 140 to the fuselage. In some examples, the upper surface of the radome mounting structure 210 may be a flat surface aligned in the xy plane, or may have a flat or curved surface with a normal vector at least partially aligned in the z direction. In some other implementations, the radome mounting structure 210 may be omitted, and the radome 145 may be mounted directly to the vehicle 130. In some examples, the radome mounting structure 210 may be configured to be located below the field of view 175 of the antenna system 140.In some examples, the vehicle may include a fairing, which may be separate from the radome mounting structure 210.

[0039] System 200 may also include one or more attenuation feature units 220 (e.g., RF signal attenuation feature units) which may be coupled (e.g., mounted, applied, and connected) to a radome mounting structure 210 or another mounting structure (e.g., separate from antenna 141 and separate from radome mounting structure 210, such as a fairing) configured to position the attenuation feature units according to the techniques described. For example, the attenuation feature unit 220 may be different from the feature units of antenna 141 (e.g., not integrated with antenna 141) so that the attenuation feature unit 220 may be mounted to System 200 separately from one or more antennas 141. In other words, at least some attenuation feature units 220 may be mounted (e.g., attached, separately mounted, or applied) to the vehicle 130, which may include mounting via intervening mounting structures (e.g., radome mounting structure 210, fairing, or other mounting structures). Such fastening may include, among other fastening techniques, the use of threaded fasteners, rivets, pins, slots, adhesives, or any combination thereof.

[0040] In various examples, one or more attenuation feature units 220 may be coupled to the upper surface of the radome mounting structure 210, or one or more attenuation feature units 220 may be coupled to the sides of the radome mounting structure 210, or a combination thereof. The attenuation feature units 220 may include various materials, components, or assemblies, which are configured to attenuate electromagnetic transmissions from the antenna system 140 from propagation along the direction relative to the antenna system 140-a. For example, one or more attenuation feature units 220 may be coupled to the radome mounting structure 210 or other mounting structure located in or below the field of view 175 of the antenna system 140, and may be configured to attenuate electromagnetic wave transmissions of the antenna system 140 within the operating frequency band of the antenna system 140 (e.g., one or more operating frequencies).

[0041] In some examples, the attenuation feature 220 may at least partially attenuate the electromagnetic wave transmission of the antenna system 140 from propagation downwards by an angle 221 (e.g., the angle associated with the field of view 175 of the antenna system 140), the angle 221 may be measured from the surface of the radome mounting structure 210, or relative to the antenna system 140 (e.g., from the center of the antenna system 140, from the mounting surface of the antenna system 140, from one or more antennas 141, from one or more apertures 205, from the swept volume of the antenna system 140), or relative to the vehicle 130 on which the system 200 is mounted. The angle 221 may represent various angles associated with different configurations of the antenna system 140-a. The attenuation feature 220 may interfere with electromagnetic wave transmission within the region associated with the angle 221, based on the fact that the attenuation feature 220 is implemented in the radome mounting structure 210. For example, the attenuation feature 220 may be mounted on the upper surface of the radome mounting structure 210, which may be between the radome mounting structure 210 and the bottom of the antenna system 140. In some examples, the attenuation feature 220 may extend from the surface of the radome mounting structure 210 (e.g., from the top surface, from the surface of the weight-release pocket of the radome mounting structure 210, or from another location) in a height dimension (e.g., from the radome mounting structure 210) at least partially along the z-direction. Thus, in some examples, the attenuation feature 220 may be configured to attenuate the electromagnetic wave transmission of the antenna system 140 from propagating downwards from the radome mounting structure 210.

[0042] In some cases, the attenuation feature 220 may be positioned below the swept volume of the antenna system 140 (e.g., below the swept volume of the antenna system 140-b associated with the mechanical steering system). In some cases, the antenna system 140 (e.g., antenna system 140-a) may be positioned with a distance 222 above one or more attenuation feature 220 (e.g., along the z-direction). The attenuation feature 220 may be positioned below the field of view 175 of the antenna system 140 (e.g., at least partially, if not entirely below the field of view 175) (e.g., it may be mounted), but in some examples the attenuation feature 220 may additionally, among others, be positioned at the boundary of the field of view 175, or at least partially within the field of view 175, at least partially or completely (e.g., it may be mounted).

[0043] In some examples, the damping feature section 220 may be implemented along the longitudinal direction (e.g., along the x-direction, along the main direction of travel) in a direction different from that along the lateral direction. For example, in the case of a vehicle 130 having a relatively elongated body along the x-direction (e.g., the torso of the vehicle), regions 171 and 172 may be relatively larger in the yz plane than in the xz plane (e.g., extending to a relatively large angle). Therefore, in some implementations, to provide relatively higher damping (e.g., for the relatively larger regions 171 and 172 in the yz plane), the damping feature section 220 may be implemented symmetrically across the vehicle's centerline (e.g., as a left-right pair, or as a symmetrical pair across the xz plane) (e.g., as a pair). In such examples, the damping feature section 220 may consist of various ranges along the x-direction, which may be the same between different instances or types of the damping feature section 220, or may differ between different instances or types of the damping feature section 220. In some examples, such as when sufficient attenuation is provided along the centerline of the vehicle 130 (e.g., the centerline along the x-direction, the centerline in the xz-plane), the attenuation feature 220 may not be implemented along the centerline of the vehicle (e.g., from the antenna system 140), or within a region (e.g., the region in front of the antenna system 140 along the x-direction, the region behind the antenna system 140 along the x-direction, or both), or within a region having a threshold distance from the centerline (along the y-direction). In some other examples, the attenuation feature 220 may be implemented in a circular, elliptical, or polygonal arrangement (e.g., centered on the centerline of the antenna system 140, centered on the z-axis).

[0044] Figures 3A–3C show an example of a system 300 supporting a fuselage attenuation technique, as illustrated herein. System 300 may be an example of an embodiment of system 200 (e.g., an example for implementing an embodiment of an antenna signal attenuator) and includes one or more attenuation features 220-d (e.g., mounted on a radome mounting structure 210-d) configured to attenuate the electromagnetic wave transmission of antenna system 140 within the operating frequency band of antenna system 140, and the electromagnetic wave transmission includes sidelobe transmission or other transmissions along a direction different from the boresight direction (e.g., different from the direction in the field of view 175, different from the direction of peak gain). System 300 may be configured to be mounted on a vehicle 130, such as an aircraft. Embodiments of system 300 may be described with reference to the illustrated coordinate system. Figures 3A–3C illustrate system 300 from various trimetric views. For example, Figure 3A illustrates system 300 from macro view 301, Figure 3B illustrates system 300 from detail view 302, and Figure 3C illustrates system 300 from micro view 303.

[0045] In some examples, the attenuation feature 220-d may be configured to attenuate electromagnetic wave transmission along a direction having a vector component in the downward direction of the vehicle coordinate system (e.g., the negative z direction, downward from the field of view 175), including a region relative to the vehicle 130 to which the radome mounting structure 210-d or other mounting structure is attached. In some examples, the attenuation feature 220-d may attenuate electromagnetic wave transmission from propagating downward at a certain angle relative to the vehicle 130. In some cases, the attenuation feature 220-d may be configured to attenuate electromagnetic wave transmission (e.g., side lobes) between one or more apertures 205 of the antenna system 140 and the outer surface of the vehicle 130 (e.g., surface 131). In some examples, the attenuation feature 220-d may be configured for a location (e.g., along the z direction) between the swept volume of one or more antennas 141 (e.g., aperture 205) and the outer surface of the vehicle 130. In some examples, attenuating electromagnetic wave transmission may involve disrupting the coherence of electromagnetic wave transmission along a direction associated with the height dimension (e.g., along the z-direction). In some implementations, attenuating electromagnetic wave transmission may involve changing the propagation direction of electromagnetic wave transmission. For example, the attenuation feature 220-d may redirect, reflect, absorb, or re-emit electromagnetic wave transmission.

[0046] Some examples of the attenuation feature section 220 may implement one or more metamaterials (meta-materials, including a class of materials that may be called "metamaterial absorbers"), which may refer to materials that have been manipulated to have one or more properties that do not normally occur in the naturally occurring configuration of the material (e.g., by the shape of the features, by the dimensions of the features, by the spacing of the features, by the orientation of the features, by the pattern of the features, by the location of the features). For example, a metamaterial implemented in the attenuation feature section 220 may include a conductive material (e.g., copper, silver, gold, aluminum, stainless steel, or any combination thereof) configured to interact with the electromagnetic wave transmission of the antenna system 140 so as to attenuate the electromagnetic wave transmission (e.g., at one or more frequencies in the operating frequency band of the antenna system 140) (e.g., as a frequency-selective surface, as a frequency-selective volume). The metamaterial of the damping feature section 220 can be mounted in various locations, such as on the radome mounting structure 210, a fairing (separate from the radome mounting structure, for example), or other mounting structures that may be attached to the vehicle 130.

[0047] In some examples, a metamaterial (e.g., a resonant metamaterial) may include multiple conductive portions configured to resonate at one or more wavelengths, and when implemented in the attenuation feature section 220, such resonant wavelengths may correspond to the operating frequency band of the antenna system 140 (e.g., one or more operating frequencies). For example, a resonant metamaterial may include features configured in two or three dimensions to implement material features (e.g., conductive portions) along various directions. In some examples, the attenuation feature section 220 may include one or more material implementations with dimensions of features, shapes of features, spacing of features, or combinations thereof, associated with one or more frequencies in the operating frequency band of the antenna system 140 (e.g., to establish resonant properties associated with the size, shape, or pattern of the conductive portions). For example, the dimensions of a feature, the shape of a feature, the spacing of a feature, or a combination thereof may have one or more dimensions related to the wavelength of electromagnetic wave transmission, such as dimensions less than the wavelength of electromagnetic wave transmission (e.g., less than one or more wavelengths associated with the operating frequency band of the antenna system 140), dimensions equal to or close to half a wavelength of electromagnetic wave transmission (e.g., within 1 percent, within 5 percent, within 10 percent, within 25 percent), or dimensions within a range of such dimensions associated with a range of wavelengths corresponding to the operating frequency band of the antenna system 140 (e.g., a range of frequencies) (e.g., according to a pattern, according to a random arrangement).

[0048] Some examples of metamaterials that can be implemented in the damping feature section 220 may not be associated with resonance phenomena (for example, they may be different from resonant metamaterials). For example, non-resonant metamaterials may include, or be referred to as, artificial magnetic conductors (AMCs), which may be configured to mitigate surface wave propagation. In some examples, the AMC may be configured to attenuate surface wave propagation, which may be the main mechanism for undesirable emission in deep shadow regions (e.g., region 173).

[0049] In some examples of the system 300, the attenuation feature section 220-d may include, among other attenuation feature sections 220-d, one or more conductive structures 305, one or more sawtooth structures 310, one or more composite conductor structures 315, or multiple segmented rings 320 (e.g., segmented conductive rings), or a combination thereof. Additionally or alternatively, the attenuation feature section 220-d may include a conductive coating applied to the radome mounting structure 210-d, or a material (e.g., a forming material, a bulk material bonded to the outer surface of the radome mounting structure 210-d configured to absorb at least a portion of electromagnetic wave transmission), or a combination thereof. The attenuation feature section 220-d may be mounted on one or more surfaces of the radome mounting structure 210-d or other mounting structures, for example, the conductive structure 305, the sawtooth structure 310, or the composite conductor Body structures 315, or combinations thereof, may be mounted on the upper surface 325 of the radome mounting structure 210-d. In some cases, the conductive structure 305 may be adjacent to the serrated structure 310 (e.g., along the y-direction), among other mounting configurations, and the composite conductor structure 315 may be adjacent to the conductive structure 305 (e.g., along the y-direction). Additionally or alternatively, the split ring 320 may be coupled to the side surface 326 of the radome mounting structure 210-d (e.g., mounted to it, fitted into it).

[0050] The composite conductor structure 315 may include a conductor portion 317 arranged on a dielectric portion 316 and may be an example of a metamaterial (e.g., a resonant metamaterial) configured to reduce surface wave propagation. For example, each composite conductor structure 315 may include a dielectric portion 316 extending along (e.g., across) the upper surface 325 of the radome mounting structure 210-d, and a certain amount of conductor portions 317 arranged in a pattern on the dielectric portion 316. The conductor portions 317 may be arranged in a grid-like pattern or an alternating pattern, among other patterns, and may be configured to resonate at one or more wavelengths corresponding to the operating frequency band of the antenna system 140. In some examples, the conductor portions 317 may be formed according to printed circuit board (PCB) techniques, such as preferentially removing a portion of the layer of conductive material (e.g., copper) formed on a layer of dielectric material (e.g., glass fiber). In some examples, the conductor portions 317 may be the same size, or subsets of the conductor portions 317 may be of different sizes. In some examples, the conductor portion 317 may be molded to form a rectangular or hexagonal shape, among other shapes configured to attenuate electromagnetic wave transmission. The conductor portion 317 may have one or more sizes, one or more shapes, one or more spacings, or combinations thereof based on the operating frequency band of the antenna system 140 (e.g., one or more operating frequencies), such that the dimensions or pattern of the conductor portion 317 may be associated with attenuating electromagnetic wave transmission at one or more frequencies of the operating frequency band. Thus, the material formed on the conductor portion 317 may be configured to interact with electromagnetic wave transmission to attenuate it (e.g., at one or more frequencies of the operating frequency band of the antenna system 140). Although illustrated as being coupled with the radome mounting structure 210-d, the composite conductor structure 315 may be additionally or alternatively mounted directly to the fuselage of the vehicle 130.

[0051] The segment ring 320 may be another example of a metamaterial (e.g., a resonant metamaterial), and the segment ring 320 may also be an example of a conductive portion configured to resonate at one or more wavelengths corresponding to the operating frequency band of the antenna system 140. The segment ring 320 may include conductive material along the surface (e.g., side 326) of the radome mounting structure 210-d, such as conductive material that can be embedded into the surface of the radome mounting structure 210-d. In some examples, the segment ring 320 may be molded, injected, or deposited (e.g., sprayed according to a masking pattern) onto the side 326 of the radome mounting structure 210-d. Additionally or alternatively, the segment ring 320 may be mounted onto the side 326 of the radome mounting structure 210-d. Each segment ring 320 may include conductive material extending perpendicularly to the side 326 of the radome mounting structure 210-d. In some examples, one or more of the dividing rings 320 (e.g., each of them) may include an outer ring 321 and an inner ring 322 made of conductive material, and the orientation of the divisions between the dividing rings 320 may be aligned along the same direction or along different directions (e.g., at random angles to depolarize electromagnetic wave transmissions to disrupt the coherence of electromagnetic wave transmissions). In some examples, the dividing rings 320 may be arranged in a grid-like pattern along the side 326. In some implementations, the conductive material may be PCB material (e.g., a conductive layer). In some implementations, the conductive material may be an example of a metamaterial configured to interact with electromagnetic wave transmissions such that the dividing rings 320 are designed to attenuate electromagnetic wave transmissions (e.g., at a certain frequency). In some examples, the dividing rings 320 may be configured to depolarize electromagnetic wave transmissions. In some such examples, the dividing rings 320 may depolarize electromagnetic wave transmissions extending downward at a certain angle with respect to the upper surface 325 of the radome mounting structure 210-d by reducing the radiation associated with the electromagnetic wave transmissions.In some other examples, such techniques may be implemented additionally or alternatively with pin structures, which may be injection molded into the radome mounting structure 210 or machined into appliqués or adapters coupled to the radome mounting structure 210. The segmented ring 320 illustrated in system 300 includes a segmented circular ring, but the segmented ring may include other shapes such as elliptical, polygonal, and other regular or irregular shapes, including various conductive shapes that resonate or nearly resonate at one or more frequencies in the operating frequency band of the antenna system 140. Furthermore, although the segmented ring 320 is illustrated as an implementation on side 326, the segmented ring 320 may be implemented additionally or alternatively on another surface of the radome mounting structure 210, such as surface 325 or other surfaces. In some examples, the split ring 320 may be additionally or alternatively mounted on a fairing or other structure for installation on the vehicle 130, which may be separate from the radome mounting structure 210, separate from the radome 145, or separate from both.

[0052] The conductive structure 305 may include an arrangement of multiple conductive pillars 306 and may be an example of a metamaterial (e.g., a non-resonant metamaterial) such as AMC, configured to reduce surface wave propagation. Each conductive structure 305 may include a certain number of conductive pillars 306 arranged in a pattern (e.g., in the xy plane) on the upper surface 325 of the radome mounting structure 210-d. In some cases, the conductive pillars 306 may be arranged in a grid-like pattern, and the attenuation characteristics of the conductive pillars 306 may depend on the dimensions, shape, or pattern (e.g., spacing of the pattern) which may depend on the operating frequency band of the antenna system 140 (e.g., one or more operating frequencies). Thus, the dimensions or pattern of the conductive pillars 306 may be associated with attenuating electromagnetic wave transmission at one or more frequencies in the operating frequency band. The conductive pillars 306 may extend for a certain distance along the z direction (e.g., along the height dimension) from the upper surface 325 of the radome mounting structure 210-d. The conductive pillar 306 may be a prism or pyramidal structure extending upward from the upper surface 325 (for example, along the z-direction). For example, the conductive pillar 306 may have a rectangular cross-section in the xy-plane, which may be straight along the z-direction or tapered along the z-direction. In some cases, the conductive pillar 306 may be formed on the conductive base structure 307 such that the conductive pillar 306 may be arranged in a pattern on the conductive base structure 307 and extend from the conductive base structure 307. In some implementations, the conductive structure 305 may be formed using a sheet metal diffraction grating pattern. In other implementations, the conductive structure 305 may be formed using a machined or cast corrugated pattern. Although illustrated to be coupled with the radome mounting structure 210-d, the conductive structure 305 may be additionally or alternatively mounted directly to the fuselage of the vehicle 130.

[0053] The sawtooth structure 310 may include an arrangement of a plurality of conductive sawtooth bodies 311. For example, each sawtooth structure 310 may include a certain amount of conductive sawtooth bodies 311 arranged in a pattern on the upper surface 325 of the radome mounting structure 210-d. In some cases, the conductive sawtooth bodies 311 may be arranged in one or more rows extending into the opening 211-a of the radome mounting structure 210-d. In some such cases, the conductive sawtooth bodies 311 may be spaced along one or more rows such that each conductive sawtooth body 311 can be separated from an adjacent conductive sawtooth body 311 by a certain distance (e.g., along the x-direction). In some examples, one or more conductive sawtooth bodies 311 may extend into the opening 211-a coplanar with the upper surface 325 of the radome mounting structure 210-d (e.g., along the y-direction in the xy-plane). In some other examples, the conductive sawtooth 311 may extend into the opening 211-a at an angle to the upper surface 325 of the radome mounting structure 210-d (for example, along a direction in the yz plane with the x-direction as the center). In some implementations, a subset of the conductive sawtooth 311 may extend at an angle to the upper surface 325, and another subset of the conductive sawtooth 311 may extend at a different angle to the upper surface 325.

[0054] The conductive sawtooth 311 may have angles, sizes, shapes, or spacings, or combinations thereof, based on the operating frequency band of the antenna system 140, such that the dimensions or pattern of the conductive sawtooth 311 may be associated with attenuation of electromagnetic wave transmission at one or more frequencies in the operating frequency band. For example, the angles, sizes, shapes, or spacings of the conductive sawtooth 311 or a subset of the conductive sawtooth 311 may be configured to interfere with electromagnetic wave transmission in a region relative to the system 300 (e.g., sidelobe emission). In some implementations, the sawtooth 311 may have one or more dimensions extending beyond the wavelength of the electromagnetic wave transmission to be attenuated and may operate according to a geometric optical system or diffraction device. In some examples, the conductive sawtooth 311 may have the same size (e.g., the same length along the y-direction), or subsets of the conductive sawtooth 311 may have different sizes (e.g., different sizes associated with a range of wavelengths corresponding to the operating frequency band of the antenna system 140, which may include sequences of different sizes or dispersed or random arrangements of different sizes). In some examples, the conductive sawtooth bodies 311 may be shaped such that each conductive sawtooth body 311 forms a triangular structure (for example, in the xy-plane). The conductive sawtooth bodies 311 may be made from conductive materials including copper, aluminum, stainless steel, or any combination thereof. Thus, the material formed on the conductive sawtooth bodies 311 may be configured to interact with electromagnetic wave transmission to attenuate it (for example, at one or more frequencies in the operating frequency band of the antenna system 140).

[0055] Figures 4A and 4B show examples of composite conductor structures 315-a supporting the fuselage attenuation technique, as illustrated herein. Composite conductor structures 315-a and 315-b may be implemented in system 200 or system 300 (for example, as an embodiment of an antenna signal attenuator). For example, composite conductor structures 315-a and 315-b may be connected to a radome mounting structure 210 or other mounting structure. Embodiments of composite conductor structures 315-a and 315-b may be described with reference to the illustrated coordinate system. Figures 4A and 4B illustrate composite conductor structures 315-a and 315-b in an overall top view and a detailed top view enlarged from the overall top view. Composite conductor structures 315-a and 315-b may be configured to attenuate the electromagnetic wave transmission of antenna system 140 at one or more frequencies in the operating frequency band of antenna system 140.

[0056] The composite conductor structures 315-a and 315-b may each include dielectric portions 316-a and 316-b, and conductor portions 317-a and 317-b, respectively, where the dielectric portion 316 may form the base structure for the conductor portion 317. The composite conductor structure 315 may include a metamaterial (e.g., a resonant metamaterial) that can be implemented according to one or more PCB techniques (e.g., as a PCB metamaterial). In various examples, such a material may include a standard or impedance-controlled substrate (e.g., as a dielectric portion 316). In some examples, the composite conductor structures 315-a and 315-b may each include vias 415-a and 415-b, where vias 415-a and 415-b may provide conductive paths from the surface structure to a ground layer (e.g., a copper ground surface), where the ground layer may be clamped to a ground source of the radome mounting structure 210 to provide RF grounding.

[0057] Figure 4A illustrates a composite conductor structure 315-a in which the conductor portions 317-a are arranged in an alternating pattern. For example, the conductor portions 317-a may be arranged in column 405-a, where each column 405-a is alternating with respect to the x-direction. That is, the conductor portions 317-a in column 405-a may be alternating with the conductor portions 317-a in the adjacent column 405-b along the x-direction. Similarly, the conductor portions 317-a may be arranged in row 410-a, in which case the conductor portions 317-a in row 410-a are alternating within row 410-a with respect to the x-direction. Although Figure 4A illustrates the conductor portions 317-a as a hexagonal shape, similar techniques can be implemented for other shapes (round, circular, elliptical, polygonal, triangular, octagonal).

[0058] Figure 4B illustrates a composite conductor structure 315-b in which conductor portions 317-b are arranged in a grid pattern. For example, conductor portions 317-b may be placed in column 405-b, and the conductor portions 317-b in column 405-b are aligned within column 405-b with respect to the y-direction. Similarly, conductor portions 317-b may be placed in row 410-b, in which case the conductor portions 317-b in row 410-b are aligned within row 410-b with respect to the x-direction. Although Figure 4B illustrates the conductor portions 317-b as a rectangular (e.g., square) shape, similar techniques can be implemented for other shapes (circular, round, elliptical, polygonal, triangular, octagonal).

[0059] Figure 5 shows an example of a system 300-a supporting a fuselage attenuation technique, as illustrated herein. System 300-a may be an example of an embodiment of system 200 (for example, an example for implementing an embodiment of an antenna signal attenuator) and includes one or more attenuation features 220-e (e.g., mounted on a radome mounting structure 210-e) configured to attenuate the electromagnetic wave transmission of antenna system 140-d at one or more frequencies within the operating frequency band of antenna system 140-d, and the electromagnetic wave transmission includes sidelobe transmission or other transmissions along a direction different from the boresight direction (e.g., different from the direction in the field of view 175, different from the direction of the peak gain). System 300-a may be configured to be mounted on a vehicle 130 such as an aircraft. Embodiments of system 300-a may be described with reference to the illustrated coordinate system. For example, Figure 5 illustrates system 300-a from a trimetric view.

[0060] In the example of system 300-a, the damping feature section 220-e may include a conductive structure 305-a, a composite conductive structure 315-c, and a split ring 320-a (for example, implemented symmetrically across the xz plane). The conductive structure 305-a may extend along the upper surface 325-a of the radome mounting structure 210-e and may include a certain amount of conductive pillars 306-a. The conductive pillars 306-a may be arranged in a grid-like pattern such that the conductive structure 305-a may include one or more rows of conductive pillars 306-a. The conductive pillars 306-a may be pyramidal structures extending along a direction perpendicular to the upper surface 325-a of the radome mounting structure 210-e. In some cases, the conductive pillars 306-a may extend upward from the upper surface 325-a of the radome mounting structure 210-e. However, in some cases, the conductive pillar 306-a may extend from below the upper surface 325-a of the radome mounting structure 210-e. For example, the conductive pillar 306-a may be embedded within the upper surface 325-a of the radome mounting structure 210-e. In some examples, the radome mounting structure 210-e may include a pocket which can be associated with reducing the weight of the radome mounting structure 210-e, and the conductive pillar 306-a may be inserted into or formed within the pocket. In some implementations, the conductive pillar 306-a may be made from a metamaterial or bulk material (e.g., foam material) associated with attenuating electromagnetic wave transmission. In some such implementations, the conductive pillar 306-a may at least partially absorb electromagnetic wave transmission.

[0061] Figure 6 shows an example of system 300-b supporting a fuselage attenuation technique, as illustrated herein. System 300-b may be an example of an embodiment of system 200 (e.g., an example for implementing an embodiment of an antenna signal attenuator) and includes one or more attenuation features 220-f (e.g., mounted on a radome mounting structure 210-f) configured to attenuate the electromagnetic wave transmission of antenna system 140-d at one or more frequencies within the operating frequency band of antenna system 140-d, and the electromagnetic wave transmission includes sidelobe transmission or other transmission along a direction different from the boresight direction (e.g., different from the direction in the field of view 175, different from the direction of peak gain). System 300-b may be configured to be mounted on a vehicle 130 such as an aircraft. Embodiments of system 300-b may be described with reference to the illustrated coordinate system. For example, Figure 6 illustrates system 300-b in an overall trimetric view and a detailed trimetric view enlarged from the overall trimetric view.

[0062] In the example of system 300-b, the attenuation feature section 220-f may include a conductive structure 305-b, a composite conductive structure 315-d, and a conductive coating 605. The conductive coating 605 may extend along the side surface 326-a of the radome mounting structure 210-f. For example, the conductive coating 605 may extend for a certain distance along the x-direction, and may extend from the bottom surface 610 of the radome mounting structure 210-c to the top surface 325-b of the radome mounting structure 210-c, or some portion thereof (for example, along the z-direction). In some cases, the conductive coating 605 may be applied to the side surface 326-a of the radome mounting structure 210-c. For example, the conductive coating 605 may be sprayed along the side surface 326 by an applicator. In some other examples, the conductive coating 605 may be embedded into the side surface 326 during the manufacturing of the radome mounting structure 210-f. The conductive coating 605 may include a conductive material or metamaterial associated with attenuating electromagnetic wave transmission. In some such implementations, the conductive coating 605 may at least partially absorb (e.g., block) electromagnetic wave transmission. In some examples, the conductive coating 605 may be a paint that includes the infusion of a conductive material or metamaterial. For example, the conductive coating 605 may be a copper paint (e.g., a copper-infused adhesive paint). In some cases, a protective coating may be applied over the conductive coating 605.

[0063] In some cases, system 300, such as system 300-b, may include materials associated with absorbing electromagnetic wave transmission (e.g., material structures, bulk materials, foamed materials, etc., not illustrated). Such materials may differ from metamaterials in that they support attenuation techniques as a function of the bulk properties of the material (e.g., separate from shape or pattern-dependent attenuation). Such materials may include homogeneous materials or mixtures such as iron-filled epoxy and other composite materials. In some examples, such materials may be mounted on or implemented within the radome mounting structure 210-f. That is, the material may be implemented alongside or within the sidewalls of the radome mounting structure 210-f so as to function as an electromagnetic absorption feature. In some examples, such materials may be implemented within the opening 211-f of the radome mounting structure 210-f. In some examples, such materials may be implemented in contact with the radome 145 (e.g., not illustrated) mounted on the radome mounting structure 210-f.

[0064] Figure 7 shows an example of a system 300-c supporting a fuselage attenuation technique, as illustrated herein. System 300-c may be an example of an embodiment of system 200 (for example, an example for implementing an embodiment of an antenna signal attenuator) and includes one or more attenuation features 220-g (e.g., mounted on a radome mounting structure 210-g mounted symmetrically across the xz plane) configured to attenuate the electromagnetic wave transmission of antenna system 140-e at one or more frequencies within the operating frequency band of antenna system 140-e, and the electromagnetic wave transmission includes sidelobe transmission or other transmission along a direction different from the boresight direction (e.g., different from the direction in the field of view 175, different from the direction of the peak gain). System 300-c may be configured to be mounted on a vehicle 130 such as an aircraft. Embodiments of system 300-c may be described with reference to the illustrated coordinate system.

[0065] In the example of system 300-c, the damping feature section 220-g may include a conductive structure 305-c, a sawtooth conductor 310-c, and a composite conductor structure 315-c (e.g., on surface 325-c), and a split ring 320-c (e.g., on surface 326-c), and the damping feature section 220-g may be implemented symmetrically across the xz plane. In the example of system 300-c, the radome mounting structure 210-g may include an interface 705 for coupling with the antenna system 140-e (e.g., with the mechanical steering system of the antenna system 140-e). The radome mounting structure 210-g may include an interface 705 for mounting the antenna system 140-e to the vehicle 130. In various examples, the interface 705 may include one or more mounting locations (e.g., mounting pads, mounting points) of any number, which may support various mounting techniques such as fastening, slotting, pinning, welding, and other techniques, or combinations thereof.

[0066] Accordingly, according to these and other examples, a system (e.g., system 200, system 300, antenna signal attenuator, signal attenuation feature 220) may be mounted on a vehicle 130 to mitigate signal propagation that may interfere with other devices or other communication systems. The system may include mounting structures such as a radome mounting structure 210 or other structures configured to couple with the surface of the vehicle 130 via an interface 215. The system may include one or more attenuation feature 220 (e.g., metamaterials, AMC, and other features) configured to attenuate electromagnetic wave transmission of the antenna system 140 (e.g., at one or more frequencies in the operating frequency band of the antenna system 140, within or below the field of view of the antenna system 140). For example, the attenuation feature 220 can interfere with, absorb, redirect (e.g., reflect, absorb, and re-emit) or modify (e.g., interfere with coherence, depolarize) electromagnetic wave transmissions propagating outside the field of view of the antenna system 140 relative to the vehicle 130, thereby reducing interference caused by electromagnetic wave transmissions outside the field of view. In some examples, the attenuation feature 220 may be configured to restrict electromagnetic wave transmissions propagating at a certain angle downward relative to the vehicle 130 (e.g., below the field of view 175), which can prevent electromagnetic wave transmissions from interfering with radio signaling communicated by other devices (e.g., ground-based devices) that may use a similar radio spectrum.

[0067] These methods illustrate examples of implementations, and it should be noted that the operations and steps may be reconfigured or otherwise modified to allow for other implementations. In some examples, two or more embodiments of the methods may be combined. For example, each embodiment of this method may include steps or embodiments of other methods, or other steps or techniques described herein.

[0068] The modes for carrying out the invention described above in relation to the attached drawings are illustrative and do not represent the only possible examples or the only examples within the scope of the claims. The term “example” as used herein means “serving as an example, illustration, or illustrative example,” and does not mean “preferred” or “superior to other examples.” The modes for carrying out the invention include specific details for the purpose of providing an understanding of the described techniques. However, these techniques can be practiced without these specific details. In some cases, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0069] The information and signals described herein may be represented using any of the various different technologies and techniques. For example, the data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout this specification may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0070] When used herein, including in the claims, “or” in a list of items (e.g., a list of items preceded by phrases such as “at least one” or “one or more”) means an inclusive list, such as “a list of at least one of A, B, or C” meaning A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” should not be interpreted as a reference to a closed set of conditions. For example, an exemplary step described as “based on condition A” could be based on both condition A and condition B without departing from the scope of this disclosure. In other words, when used herein, the phrase “based on” shall be interpreted in the same way as the phrase “based at least in part on.”

[0071] In the attached drawings, similar components or features may have the same reference label. Furthermore, various components of the same type may be distinguished by adding a dash after the reference label and adding a second label to differentiate between similar components. Where only the first reference label is used herein, the description is applicable to any one of the similar components having the same first reference label, regardless of the second reference label or any other subsequent reference labels.

[0072] The descriptions herein are provided to enable those skilled in the art to create or use this disclosure. Various modifications to the disclosure will be obvious to those skilled in the art, and the general principles defined herein may apply to other variations without departing from the scope of the disclosure. Thus, this disclosure is not limited to the examples and designs described herein, but is given the broadest scope that corresponds to the principles and novel features disclosed herein.

Claims

1. An antenna signal attenuation device, A radome mounting structure (210) configured to connect a radome (145) to the outer surface (131) of a vehicle (130), wherein the radome is associated with a volume for arranging an antenna system (140) having a boresite (180) that can be configured within a field of view (175) and an operating frequency band, An antenna signal attenuation device comprising: one or more signal attenuation feature units (220) mounted on the radome mounting structure and located below the field of view of the antenna system, wherein the one or more signal attenuation feature units (220) are configured to attenuate the electromagnetic wave transmission of the antenna system within the operating frequency band.

2. The antenna signal attenuation device according to claim 1, wherein one or more signal attenuation feature units are configured to attenuate the electromagnetic wave transmission between the antenna system and the outer surface of the vehicle.

3. The antenna signal attenuation device according to claim 1 or 2, wherein the radome mounting structure is configured with an opening (211), and the antenna system can be mounted on the vehicle through the opening (211).

4. The antenna signal attenuation device according to claim 1 or 2, wherein the radome mounting structure includes an interface (705) for mounting the antenna system to the vehicle.

5. The antenna signal attenuator according to any one of claims 1 to 4, further comprising the antenna system, wherein the antenna system has a steering system (135) configured to steer the boresight within the field of view.

6. The antenna signal attenuator according to any one of claims 1 to 5, wherein the one or more signal attenuation feature portions are configured with respect to a location between the swept volume of one or more antennas (141) of the antenna system and an interface (215) for coupling the radome mounting structure with the outer surface of the vehicle.

7. The antenna signal attenuation device according to any one of claims 1 to 6, wherein two or more of the signal attenuation feature units are configured to be mounted symmetrically across the centerline of the vehicle.

8. The antenna signal attenuation device according to any one of claims 1 to 7, wherein the one or more signal attenuation feature sections are not configured to be in a location along the centerline of the vehicle.

9. The antenna signal attenuation device according to any one of claims 1 to 8, wherein one or more signal attenuation feature units are configured to interfere with the coherence of the electromagnetic wave transmission.

10. The antenna signal attenuation device according to any one of claims 1 to 9, wherein one or more signal attenuation feature units are configured to change the propagation direction of the electromagnetic wave transmission.

11. The one or more signal attenuation feature units, An antenna signal attenuator according to any one of claims 1 to 10, comprising one or more metamaterials configured to interact with the electromagnetic wave transmission.

12. The antenna signal attenuator according to claim 11, wherein the one or more metamaterials include a plurality of conductive portions configured for resonance at one or more wavelengths corresponding to the operating frequency band.

13. The antenna signal attenuator according to claim 12, wherein the resonance is associated with the size, shape, or pattern of the plurality of conductive portions that are at least partially based on one or more wavelengths.

14. The one or more signal attenuation feature units, The antenna signal attenuation device according to claim 13, comprising one or more composite conductor structures (315), each comprising a dielectric portion (316) and a set of multiple conductor portions (317) from the multiple conductor portions coupled to the respective dielectric portion.

15. The plurality of conductive parts The antenna signal attenuation device according to claim 13 or 14, comprising a plurality of segmented conductive rings (320) applied to the side surface of the radome mounting structure.

16. The antenna signal attenuation device according to claim 15, wherein the plurality of divided conductive rings are configured to depolarize the electromagnetic wave transmission.

17. The one or more metamaterials described above The antenna signal attenuation device according to claim 11, comprising one or more conductive structures (305), each comprising a plurality of conductive pillars (306) which are coupled to the upper surface of the radome mounting structure and each extends above the upper surface of the radome mounting structure.

18. The antenna signal attenuation device according to claim 17, wherein each of the plurality of conductive pillars is arranged in a grid pattern that is at least partially based on the operating frequency band.

19. The antenna signal attenuation device according to claim 17 or 18, wherein each of the plurality of conductive pillars includes a rectangular cross-section extending along a direction perpendicular to the upper surface of the radome mounting structure.

20. The antenna signal attenuation device according to any one of claims 17 to 19, wherein each of the plurality of conductive pillars includes a pyramidal structure extending in a direction perpendicular to the upper surface of the radome mounting structure.

21. The one or more signal attenuation feature units, An antenna signal attenuation device according to any one of claims 1 to 20, comprising one or more sawtooth structures (310) connected to the upper surface of the radome mounting structure, each comprising a plurality of conductive sawtooth bodies (311).

22. The antenna signal attenuation device according to claim 21, wherein each of the plurality of conductive sawtooth bodies extends in the same plane as the upper surface of the radome mounting structure.

23. The antenna signal attenuation device according to claim 21, wherein each of the plurality of conductive sawtooth bodies extends at one or more angles with respect to the upper surface of the radome mounting structure.

24. The antenna signal attenuation device according to claim 21, wherein each of the plurality of conductive sawtooth bodies includes a subset of first conductive sawtooth bodies extending at a first angle with respect to the upper surface of the radome mounting structure, and a subset of second conductive sawtooth bodies extending at a second angle different from the first angle with respect to the upper surface of the radome mounting structure.

25. The antenna signal attenuator according to any one of claims 21 to 24, wherein each of the plurality of conductive sawtooth bodies has one or more sizes, one or more shapes, one or more spacings, or a combination thereof, based at least partially on the operating frequency band.

26. The one or more signal attenuation feature units, An antenna signal attenuator according to any one of claims 1 to 25, comprising a conductive coating (605) applied to the side surface (326) of the radome mounting structure.

27. The one or more signal attenuation feature units, An antenna signal attenuator according to any one of claims 1 to 26, comprising a material coupled to the outer surface of the radome mounting structure and configured to absorb at least a portion of the electromagnetic wave transmission.

28. The antenna signal attenuation device according to any one of claims 1 to 27, wherein one or more signal attenuation feature units are configured to attenuate the electromagnetic wave transmission by preventing it from propagating downward to the radome mounting structure.

29. The antenna signal attenuation device according to any one of claims 1 to 28, wherein the radome mounting structure is configured to be located below the field of view of the antenna system.

30. The aforementioned antenna system, The antenna signal attenuation device according to any one of claims 1 to 29, further comprising the radome.

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