Abstract: The present invention relates to the technical field of underwater communications, and discloses a bridging transmission device for underwater wireless signals, which includes a coaxial cable and two conversion assemblies. The coaxial cable can transmit the weak electric signal. The transmission device transmits and converts wireless signals by means of signal bridging between two or among more independent intelligent terminal devices, converts the electromagnetic wave signal and the weak electric signal to each other through two groups of conversion antennas, and transmits the weak electric signal under water through the coaxial cable, so the purpose of the remote transmission of underwater wireless signals can be achieved. The conversion assembly has no need to be wired to the intelligent terminal device through an interface, so the waterproof performance is good, and the universality is high.

Abstract: A deployment module according to the present application enables both compact stowage of a sensor array and expansion of the sensor array into a three-dimensional volumetric array shape that enables improved directionality of the sensors during operation. The deployment module includes a support shell that is configured to retain a cable of the sensor array separately from sensors of the sensor array and an expandable deployment body formed of a superelastic shape memory alloy that uses superelasticity and stored energy for deployment of the sensor array. During deployment, the deployment body is removed from the support shell and the sensors are subsequently pulled out of the support shell. The deployment body then expands and holds the cable to retain the three-dimensional volumetric shape of the deployed array.

Abstract: The system for an antenna assembly for use on unmanned underwater vehicles (UUV). The antennas are low-cost, lightweight, single-use, and have a small form factor amenable to use on a micro-UUV. A central post and pivotally attached arms form an antenna (e.g., a monopole) that is lifted via an aerial, kite, or the like, when deployed from the UUV to extend the line of site of the antenna several meters above the surface of the water. In some cases, the antenna may be used on a number of UUVs in a swarm formation.

Abstract: A stabilization adapter is provided for a portable antenna. The adapter includes a clamp, a rod and a counterweight. The clamp connects to a stand of the antenna. The rod adjustably attaches at its proximal end to the clamp. The counterweight attaches the rod at its distal end.

Abstract: A helicoidal, mixed polarization mono-conical antenna has: a supporting structure (2) with a longitudinal axis (2a); ground conductors (3) connected to an area around a first portion (4) of the supporting structure (2) defining a ground plane (21) of the antenna (1) orthogonal to the axis (2a); at least three signal conductors (7), which have respective first ends (8) that are connected to a second portion (5) of the supporting structure (2) and respective second ends (10) that are connected to a third portion (6) of the supporting structure (2) located between the first portion (4) and the second portion (5) along the axis (2a), the conductors wound in a helicoidal manner relative to the axis (2a) and shaped so as to define a substantially frusto-conical volume (12) which is coaxial to the axis (2a) and is oriented with a smaller base towards the first portion (4).

Abstract: The present invention relates to an underwater radio frequency antenna able to radiate in an underwater or equivalent propagation medium. It comprises a hollow conducting tube forming a resonant cavity, said conducting tube having an open end and a closed end, means of excitation of said resonant cavity which area able to be fed with signals and are arranged in such a way that the resonant cavity emits an electromagnetic radiation through said open end, at least one layer of dielectric material filling at least partially said resonant cavity so as to close the open end of the resonant cavity and render said cavity leaktight in relation to the underwater medium and to allow said electromagnetic radiation to pass through.

Abstract: An antenna includes a polymer coating having a VLF/LF element and an HF/VHF element embedded therein. A blocking choke is interposed between the VLF/LF element and the antenna feed t block HF/VHF signals. Small chokes are regularly positioned on the VLF/LF element to eliminate resonances caused by mutual capacitance between the elements. Reactive loads are positioned in said HF/VHF element at regular intervals for optimizing performance of the antenna in the HF/VHF radio bands. In further embodiments the antenna is provided as a floating antenna with the elements helically arranged therein.

Abstract: There is disclosed a mobile terminal including a case, a first antenna mounted in the case to perform wireless communication in a specific frequency band, a grounding surface mounted in the case, a receiver mounted in the case, toward a front surface of the case, a battery cover coupled to a rear surface of the case, the battery cover comprising a conductive portion, and a contact pin configured to connect the conductive portion and the grounding surface with each other, wherein the contact pin is formed in a predetermined portion where a phase of an electromagnetic field formed by the first antenna changes. The mobile terminal may adjust the HAC grade to a base grade or higher of the HAC by adjusting the position of the electromagnetic field peak, regardless of the size of the mobile terminal.

Abstract: Communications antennae suitable for operating in harsh environmental conditions and methods for providing such antennae are disclosed. Exemplary implementations of the communications antenna may provide an ability to transmit and receive radio frequency signals while being exposed to formidable conditions for many years. Such conditions may include one or more of shallow and deep ocean, radioactive, ultraviolet, ultra cold, ultra-high pressure, and/or other harsh environments. The antenna may be ruggedized to withstand attacks by marine mammals and fish, encounters with fishing equipment including nets and lines, entanglement with marine debris, abrasion (e.g., by coral, sand, rock, and/or other objects), collision with maritime vessels and submersibles, and/or other unpredictable events. The efficient radio frequency design and efficient form factor may provide users with a small, unobtrusive device with a capacity for extensive integration in the radio frequency domain.

Abstract: An antenna includes a polymer coating having a VLF/LF element and an HF/VHF element embedded therein. A blocking choke is interposed between the VLF/LF element and the antenna feed to block HF/VHF signals. Small chokes are regularly positioned on the VLF/LF element to eliminate resonances caused by mutual capacitance between the elements. Reactive loads are positioned in said HF/VHF element at regular intervals for optimizing performance of the antenna in the HF/VHF radio bands. In further embodiments the antenna is provided as a floating antenna with the elements helically arranged therein.

Abstract: A method and system for communication with assemblies comprising shafts (e.g., drive shafts, or other rotating objects) comprising use of helical antenna based components. In this regard, a helical antenna based component may comprise one or more helical antennas surrounding or wound around a shaft, with the one or more helical antennas being electrically decoupled from the shaft, and with the helical antenna based component being configurable to communicate the signals when the shaft is stationary or rotating.

Abstract: A multirotor mobile buoy combining MR-VTOL capability with environmentally hardened electronics, exchangeable sensor suites, and a solar recharge system and providing sensing in aquatic environments. The multirotor mobile buoy provides for the detection, classification and location of underwater objects using self-contained electronics, and repositions with aerial means using a plurality of rotors. The multirotor mobile buoy additionally incorporates solar panels for recharging of on-board batteries enabling the flight and other functions, and comprises a buoyant assembly and extended tether in order to promote stability in dynamic, open ocean environments. The multirotor mobile buoy may be employed singly or as a swarm of underwater detection platforms, and may utilize its positioning ability to optimize the effectiveness of sonobuoy systems arrayed as a distributed sensor field.

Abstract: An underwater top-pivoting antenna assembly (or array thereof) suitable for subsurface RFID tag interrogation in flowing water such as a river. In preferred embodiments, the antenna interrogates RFID tags implanted in aquatic species. The antenna resides in an elongate antenna housing whose cross-sectional shape is preferably a symmetric hydrodynamic teardrop shape. When the assembly is deployed in water with an upper end thereof suspended above a lower end, the upper end of the housing is linked to a pivot/swivel mechanism such that when the pivot/swivel mechanism is held substantially stationary with respect to the water flow, the lower end of the housing is free to rotate generally about the first end, including in a substantially vertical plane parallel to the water flow direction. The length of the antenna housing is advantageously selected to enable the antenna to monitor for signals across substantially the entire water depth.

Abstract: A hybrid buoy system capable of aerial operation, that in some embodiments includes a wireless communication technology to allow communication with other buoys and/or an external system. In some embodiments, a swarm of buoys may be capable of surface and/or air operation. These buoys may work together to perform collective tasks that individual buoys are not capable of. Buoy swarms may be programmed for cooperative and swarm behaviors for use in a broad spectrum of missions. At least some of the buoys may be configured for specialized sensing, increasing the collective sensing capabilities of the swarm. A mixed, swappable sensor suite may be used to accommodate an array of marine exploration applications, including both military and civilian applications.

Abstract: A transportable weather radar having radar electronics functionally located above the elevational joint and a frame superstructure rotationally connected to the elevational joint onto which is mounted a parabolic radar antenna adapted for Doppler weather radar use. The radar has a rotational drive assembly mounted below and supporting the elevational joint and a harmonic drive unit positioned inside the elevational joint so that the antennae may be rotated without significant backlash during rotational changes. A hollow center in the rotational joint allows for the passing of electronics cable through the middle of the joint and down through rotating assemblies and to electronics in or adjacent to the radar pedestal.

Abstract: There is disclosed a broadband HF antenna, which is fully integrated on a naval ship. This antenna enables to transmit and/or receive radio-frequency waves from a naval ship. The antenna comprises a radiating element and an exciting element. The exciting element excites the radiating element when fed with current. The radiating element is a structural element of the ship itself.

Abstract: An underwater top-pivoting antenna assembly (or array thereof) suitable for subsurface RFID tag interrogation in flowing water such as a river. In preferred embodiments, the antenna interrogates RFID tags implanted in aquatic species. The antenna resides in an elongate antenna housing whose cross-sectional shape is preferably a symmetric hydrodynamic teardrop shape. When the assembly is deployed in water with an upper end thereof suspended above a lower end, the upper end of the housing is linked to a pivot/swivel mechanism such that when the pivot/swivel mechanism is held substantially stationary with respect to the water flow, the lower end of the housing is free to rotate generally about the first end, including in a substantially vertical plane parallel to the water flow direction. The length of the antenna housing is advantageously selected to enable the antenna to monitor for signals across substantially the entire water depth.

Abstract: An annular vehicle having a body which defines a body axis and appears substantially annular when viewed along the body axis. The interior of the annulus defines a duct which is open at both ends. The vehicle includes an electric field (EF) coupled dipole antenna arrangement for electro-magnetic communications, which includes at least one dipole antenna. The vehicle is used as a node in an underwater communications system for communicating with other node(s) using their EF coupled dipole antenna arrangements. The electric field coupled dipole antenna arrangement can provide communications with lower latency than systems employing acoustic communications. The annular body provides good separation for electrodes of the EF coupled dipole antenna arrangement disposed around the body.

Abstract: The invention is a buoyant cable antenna that is towed on the surface of a body of water by a submerged underwater vehicle to allow communication coverage in an omnidirectional pattern in the VHF frequency range and that is also compatible with existing buoyant cable antenna deployment and retrieval systems. The antenna of the present invention comprises a floating cable having four identical antenna elements that are arranged in a cross configuration. The antenna is designed with a system of four shielded inductor units connected in series with the antenna elements to reduce the losses to seawater by the submerged elements and to tune the exposed vertical element and its feed-cable capacitance to resonance which results in greatly increased radiated power at the design frequency of approximately 10-30 MHz.

Abstract: A pneumatic vibration isolating suspension is disclosed for supporting a payload on a moving carrier while suppressing the transmission of vibrations in the 1 to 50 Hz band between the carrier and the payload. The disclosed invention can be deployed in the air in a towed carrier or sonde, and operated from aircraft power, making it a suitable platform for airborne geophysical instrumentation. It also has particular application to airborne electromagnetic surveying operating in the same frequency band because the sensor vibrations that result in noise created by the modulation of the sensor coupling with the earth's magnetic field are suppressed. Furthermore, the invention can be constructed from resistive composite materials and non-magnetic metals, so it can be operated without producing significant modification to the ambient electromagnetic field being measured.

Abstract: The invention as disclosed is a buoyant cable antenna configured for both VLF/LF and HF signals. A 100 foot antenna element has a low-pass filter assembly positioned at the midpoint of the antenna element to block HF signals. The outboard tip of the antenna element is shorted. In this way, the antenna element appears as a 50 foot open circuit antenna element to HF signals and as a 100 foot shorted antenna element to VLF/LF signals.

Abstract: An underwater basal-pivoting antenna assembly (or array thereof) suitable for subsurface RFID tag interrogation in flowing water such as a river. In preferred embodiments, the antenna interrogates RFID tags implanted in aquatic species. The antenna resides in an elongate antenna housing whose cross-sectional shape is preferably a hydrodynamic teardrop shape. When the assembly is deployed in water with a lower end thereof anchored below an upper end, the lower end of the housing is linked to a pivot/swivel mechanism such that when the pivot/swivel mechanism is held substantially stationary with respect to the water flow, the upper end of the housing is free to rotate generally about the first end, including in a substantially vertical plane parallel to the water flow direction. The length of the antenna housing is advantageously selected to enable the antenna to monitor for signals across substantially the entire water depth.

Abstract: An underwater antenna assembly (or array thereof) suitable for subsurface RFID tag interrogation in flowing water such as a river. In preferred embodiments, the antenna interrogates RFID tags implanted in aquatic species. The antenna resides in an elongate antenna housing whose cross-sectional shape is preferably a hydrodynamic teardrop shape. A first end of the housing is linked to a pivoting mechanism such that when the pivoting mechanism is held substantially stationary with respect to the water flow, the second end of the housing is free to rotate generally about the first end in a substantially vertical plane parallel to the water flow direction. The length of the antenna housing is advantageously selected to enable the antenna to monitor for signals across substantially the entire water depth.

Abstract: A system for augmenting the coverage, information and robustness of an automatic identification system of ships incorporates standard AIS-type means, satellite links, coastal stations and processing centers handling the coordination of the means (maximizing the coverage of the system in time) and the processing of the data (merging of different information to create extended context information). The system implements a scheduling algorithm for the resources mobilized, in order to optimise the coverage by ensuring a given level of redundancy for the purposes of reliability and responsiveness of the system.

Abstract: The present disclosure relates to determining the attenuation of an electromagnetic signal passing through a conductive material. An antenna is provided and placed in relatively close proximity to the conductive material. An alternating current is passed through the antenna and the impedance of the antenna is measured. The attenuation is determined using the measured impedance. A single frequency measurement may be made, or multiple measurements using different frequencies may be made. Grouped parameters based on properties of the material and the frequency of the current are used to relate the coil impedance to the attenuation. A current frequency for which the ratio of the antenna's resistive part of the impedance to the angular frequency of the current is substantially insensitive to at least one of the parameters is preferred.

Abstract: The invention concerns a device for propagating electromagnetic waves through impure water such as seawater or brackish water. The device comprises a body of polar material, for example pure water, contained in an enclosure, and an antenna arranged to emit an electromagnetic signal into the polar material. Excitation of dipoles in the polar material by the electromagnetic signal causes them to re-radiate the signal, which is thereby emitted into and relatively efficiently propagated through the water in which the device is submerged. The device offers the possibility of improved underwater communication.

Abstract: A tethered buoy housing and deployment system includes a housing for disposition in a vessel, a tether for interconnecting a portion of the housing and a buoy, a reel mounted in the housing and rotatable to unwind the tether, means for maintaining tension on the tether as the tether is unwound, and a platform and linkage assembly adapted to support the buoy and move the buoy between a vertical disposition for storage in the housing and an angled disposition for release of the buoy into an external fluid stream.

Abstract: An antenna element with a single-conductor antenna is provided within a removable core. The removable core is mounted within a hollow liner by sliding the core into the hollow liner. A pull cable may be attached to an end of the removable core to pull the core through the outboard end of the hollow liner. Due to reduced strain on the core as compared to the liner, the single-conductor antenna may be formed in segments interconnected with capacitors for adjusting the antenna gain to a maximum in the vicinity of a desired operating frequency or frequencies.

Abstract: An apparatus for manually maintaining the level of a radar antenna mounted on a stern pole affixed to the deck or transom of a vessel providing a platform pivotably mounted to a distal end of the pole and oriented to rotate about an axis substantially parallel to the centerline of the vessel. A controller at the lower end of the pole proximal to the cockpit permits manual adjustment of the horizontal angle of the radar antenna to maintain level due to heeling of the boat. The controller utilizes a first plate secured to the pole having a series of detent positions angularly spaced around and equidistant from a center point and a second plate rotatably secured at the center point. A grip handle projecting from the front surface of the second plate permits rotation of the plate when a cooperatively aligned release handle is grasped to withdraw one or more pins extending through holes in the second plate engage the detent positions.

Abstract: A hybrid cable antenna includes a first cable antenna that is buoyant and unloaded for operation in a lower portion of the high frequency band. At least one second cable antenna is serially and electrically coupled to the first cable antenna. Each second cable antenna is buoyant and loaded for operation in a portion of the high frequency band that is above the lower portion of the high frequency band.

Abstract: An unmanned submersible vehicle for use in a body of liquid having a top surface and in air overlying the top surface includes a hull, an integral antenna, and an antenna positioning system. The hull has first and second opposed ends. The hull includes a first hull portion adjacent the first end and a second hull portion adjacent the second end. The antenna is disposed within the first hull portion and/or is mounted on the first hull portion. The antenna positioning system is configured to reorient the hull from a transit position to a signal position.

Abstract: The present invention relates to a method for designing an electrically small antenna, in one embodiment, within an enclosing volume. In a preferred embodiment, the method comprises the steps of designing the electrically small antenna which has a general cross-sectional contour shape of an oblate spheroid from a top load portion to a stem portion below the top load portion. The oblate spheroid contour shape is represented by an antenna dipole moment algorithm which includes a dipole moment term. The method further comprises the steps of controlling the amplitude of the dipole moment term, including adjusting the amplitude of the dipole moment term to independently change the oblate spheroid contour shape, resulting in a change to the electric field outside the enclosing volume and a change to the electric field inside the enclosing volume.

Abstract: An antenna comprising a first current probe having an aperture; a first transceiver operatively coupled to the current probe; a signal enhancer disposed approximately inside the aperture, wherein the signal enhancer comprises an inlet, a first outlet, and a housing having an internal volume, and wherein the outer dimensions of the housing are nearly equivalent to the dimensions of the aperture; a pump configured to pump electrolytic fluid through the internal volume via the inlet and the first outlet; and a first nozzle hydraulically coupled to the first outlet so that when electrolytic fluid is pumped through the internal volume the electrolytic fluid exits the first nozzle in a stream.

Abstract: A positioner for an antenna intended to be placed in a given or restricted volume comprises: a first axis A? ensuring the movement of the antenna in azimuth, a third axis A? ensuring the movement of the antenna in elevation, said third axis A? being orthogonal and coplanar to the first axis A?, and a second axis of rotation A? or cross-elevation axis positioned so as to intersect said first axis A? and said third axis A? at one and the same virtual point O, said virtual point O of intersection of the three axes A?, A?, A? constituting the pivot point of the movements of said antenna mounted on the positioner.

Abstract: An antenna comprises first and second radiating elements for connecting to a first and second potential levels respectively. The first and second potential levels are substantially different for generating an electrostatic field from the first and the second radiating elements. The antenna further comprises first and second field shaping structures for controlling field propagation in a first and second direction respectively. The first and second field shaping structures are interdisplaced for defining a field pathway while the first and second radiating elements are disposed adjacent to the first and second field shaping structures and along the field pathway for directing the electrostatic field in a propagation direction through a liquid medium. More specifically, the propagation direction is defined by the field pathway and substantially perpendicular to at least one of the first and second directions.

Abstract: A buoyant cable antenna system includes an HF antenna section connected to an outboard end of a VLF/LF antenna. With respect to the HF antenna, the VLF/LF appears to be a standard coaxial cable so that the HF antenna can be configured as desired for HF antenna operation. The VLF/LF antenna is comprised of a segment of coaxial cable. The inboard end of the braided outer conductor of the segment of coaxial cable is connected to ground through a capacitor so that the VLF/LF signals are effectively isolated from ground. In this way, VLF/LF currents are induced on the outer braided conductor of the segment of coaxial cable to thereby operate as the VLF/LF antenna.

Abstract: A subsurface deployable antenna array is provided which expands upon deployment and contracts for storage to provide an antenna array that can be stored in a comparatively compact space. Electronically interconnected antenna modules are connected by expandable/contractable connectors. A helically-organized bundle of optical cables and electrical wiring are utilized in the expandable/contractable connectors. Mechanical, electrical, or hydraulic means may be utilized to control the spacing between the antenna modules.

Abstract: A magnetic and/or magneto-electric antenna that has a plurality of conducting loops where each individual loop can be resonated at a frequency that is offset from the frequency of the other loops to provide a composite band-pass response that is broader than that of the individual loops. A receiving circuit acts to sum the signals from each of the antennas to provide a combined frequency response that is broader in bandwidth than any of the individual loops. Similarly a combination of multiple transmitter loops where a transmit circuit drives a common transmit waveform to each of the combined antennas to provide a combined transmitter frequency response that is broader in bandwidth than any of the individual loops.

Abstract: A marine multiband antenna array includes a nearly virtual bow tie UHF antenna and a connected VHF/FM antenna that together function as an AM antenna. A diplexer separates the AM/FM radio signals from the UHF/VHF television signals.

Abstract: The present invention is a submarine mast antenna controller for controlling a plurality of functions performed by an antenna mast of a submarine. The submarine mast antenna controller is a solid state electronic control unit on a single card that monitors various submarine mast antenna system sensors and motors, and controls electromechanical devices associated with the sensors and improves functionality over the former ACU system by consolidating control interfaces and indicators in one computer terminal via a VXI interface.

Abstract: A buoyant cable antenna system includes an HF antenna section connected to an outboard end of a VLF/LF antenna. With respect to the HF antenna, the VLF/LF appears to be a standard coaxial cable so that the HF antenna can be configured as desired for HF antenna operation. The VLF/LF antenna is comprised of a segment of coaxial cable. The inboard end of the braided outer conductor of the segment of coaxial cable is connected to ground through a capacitor so that the VLF/LF signals are effectively isolated from ground. In this way, VLF/LF currents are induced on the outer braided conductor of the segment of coaxial cable to thereby operate as the VLF/LF antenna.

Abstract: An apparatus for manually maintaining the level of a radar antenna mounted on a stern pole affixed to the deck or transom of a vessel providing a platform pivotably mounted to a distal end of the pole and oriented to rotate about an axis substantially parallel to the centerline of the vessel. A controller at the lower end of the pole proximal to the cockpit permits manual adjustment of the horizontal angle of the radar antenna to maintain level due to heeling of the boat. The controller utilizes a first plate secured to the pole having a series of detent positions angularly spaced around and equidistant from a center point and a second plate rotatably secured at the center point. A grip handle projecting from the front surface of the second plate permits rotation of the plate when a cooperatively aligned release handle is grasped to withdraw one or more pins extending through holes in the second plate engage the detent positions.

Abstract: A system for mounting a wireless antenna and equipment to a stealth communication tower in coastal areas and inland waterways, camouflaged as a sailboat. The Cellboat is retrofitted to securely and discreetly store wireless transceiver equipment, and an antenna is attached at the top of the mast. Access doors are disposed in the side of the Cellboat to provide access to the equipment for maintenance purposes. The Cellboat is stored at drydock, allowing for access and protection from flooding of the equipment. Alternatively, when the Cellboat is deployed in the water, the access doors will be located on the top deck of the Cellboat.

Abstract: An antenna stabilizing apparatus for use on a marine vessel comprises a base body, a housing, a carrier, and a limiting member. The housing is mounted on a top of the base body and internally defines a receiving space. The carrier has at least one antenna carried thereon, and is connected to the house via a hanging member to suspend in the receiving space. The limiting member interconnects the carrier and a bottom of the housing to each other and limits a displacement range allowable for the carrier. With these arrangements, the antenna stabilizing apparatus is able to minimize the adverse influence of the rolling and pitching marine vessel on the signal receiving and transmitting via the antenna mounted on the marine vessel. Therefore, the marine vessel can navigate the sea more safely and stable wireless signal transmission via the antenna mounted on the marine vessel can be ensured.

Abstract: The present invention provides a communication device and a communication method of an underwater vehicle, which use an electromagnetic field (electromagnetic wave), having a higher propagation speed than that of an acoustic wave, for communication between an underwater vehicle and a mother vessel or the like so as to allow real-time control of the underwater vehicle and the like and further to make the communication little sensitive to noise and the like. The communication device performs wireless communication between an underwater vehicle in water and an object on land or on water, and is configured to compress data to be transmitted and transmit/receive the compressed data by the use of a low-frequency electromagnetic field.

Abstract: A multi-band antenna comprising a conductive structure and a plurality of current probes coupled around the conductive structure. Each current probe is designed to receive and transmit in a substantially different frequency band than the other current probes. The current probes are positioned on the conductive structure so as to effectively create a plurality of transmit/receive antennas such that each respective antenna has a voltage standing wave ratio (VSWR) of less than or equal to approximately 3:1 for a given range within each respective frequency band.

Abstract: An underwater communication method is provided. EM signals are transmitted via a seabed using an underwater electrically insulated magnetically coupled antenna. By making use of the low loss properties of the seabed, EM signal attenuation can be reduced and consequently the transmission range can be increased. The underwater electrically insulated magnetically coupled antenna may be located within a body of water or may be buried in the seabed.

Abstract: A towable antenna system is deployable and retrievable from and tetherable to an underwater vehicle while the underwater vehicle is submerged under water. An underwater vehicle having a towable antenna system is capable of communicating with one or more remote communication systems, the towable antenna system acting as an intermediary for communications between a submerged underwater vehicle and the one or more remote communication systems.

Abstract: A structural antenna system for operation in the HF frequency range, particularly for naval communications, is described, comprising at least one linear radiating arrangement (14) adapted to be operatively associated with a ground conductor (GND) and at least one electrical impedance device (Z1-Z4), in which the aforesaid linear radiating arrangement (14) is coupled to a pre-existing naval structure which has a predominantly vertical extension and is electrically conducting, such as a funnel (F). A structural antenna system with multiple feed comprises a plurality of linear radiating arrangements (114) positioned in meridian planes of the naval structure of the funnel type (F), spaced at equal angular intervals.

Abstract: A self-contained cooling system for a phased array antenna includes a cooling structure, a heat exchanger, and a pump for circulating a fluid coolant around a coolant loop. The cooling system receives power from a remote power source. The cooling structure includes a plurality of coolant inlet pipes, a plurality of coolant outlet pipes, and a plurality of cooling platforms. Each of the cooling platforms has a coolant channel that begins at one of the plurality of coolant inlet pipes, terminates at one of the plurality of coolant outlet pipes, and provides a flow path for a fluid coolant. The cooling structure further includes at least one base plate releasably mounted to at least one of the plurality of cooling platforms. One or more antenna elements associated with the phased array antenna are mounted on the base plate releasably mounted to at least one of the plurality of cooling platforms.