The present invention relates to data communication and, more specifically, to components for facilitating data communication in applications where communication by conventional means are less than satisfactory.
For example, and not by way of limitation, in the context of underwater vehicles, like a submarine and an unmanned scout, the unmanned scout can be used collect information for transmission back to the submarine. The transmission is most effective if it supports relatively high data rates. Optical based technologies have achieved data rates in excess of 1 Gb/s but would require precisely aligned optical connectors with reasonably clean interfaces. The present inventors have recognized that millimeter-wave communication systems employing for example, a millimeter wave (MMW) generator/modulator of the type described in published US Patent App. No. US 2008/0199124 A1, with carrier frequencies between 35 GHz and 140 GHz, can support data rates in excess of 10 Gb/s and, although millimeter-waves in general are strongly attenuated when propagating through water, a millimeter-wave signal can propagate a few millimeters through water and can be used to provide a high data rate link without requiring intimate contact, clear water, a clean window, or precise alignment.
More specifically, the present inventors have explored the propagation of millimeter-waves through thin layers of sea water in the context of bio-fouled connector surfaces and connector materials of MMW data couplings and have concluded that a 35 GHz carrier, the attenuation of which is about 16.5 dB/mm in water, can support data rates up to about 5 Gb/s with relatively simple on-off keying modulation schemes and higher data rates with spectrally efficient modulation schemes such as, for example, quadrature amplitude modulation. Similarly, a 94 GHz carrier, the attenuation of which is about 35.1 dB/mm in water, can support data rates of 10 Gb/s with on-off key modulation. The present disclosure relies on photonic approaches for generating, modulating, and detecting millimeter waves, as presented in US Patent App. Nos. US 2008/0199124 A1, US 2009/0016729 A1, US 2008/0023632, and other similar publications, in the construction of data communications systems configured for reliable data transfer through water and other environments where the ambient would otherwise interfere with efficient data transfer.
In accordance with one embodiment of the present invention, a data communications system is provided comprising a submersible home vessel, a submersible satellite vessel, and a flexible dielectric waveguide cable. The flexible dielectric waveguide cable comprises an exposed dielectric face configured to transmit electromagnetic millimeter wave radiation. The submersible home vessel comprises a transparent pressure boundary that is configured to be functionally transparent to electromagnetic millimeter wave radiation and to permit unguided propagation of the electromagnetic millimeter wave radiation. The submersible home vessel further comprises a coupling portion that is configured to secure the dielectric face in a position that enables the transmission of unguided millimeter wave radiation across the transparent pressure boundary to a MMW detector within the submersible home vessel.
In accordance with another embodiment of the present invention, a submersible vessel comprising a hull, a transparent pressure boundary, a connector coupling portion, and a MMW detector is contemplated. Additional embodiments are disclosed and contemplated.
The following detailed description of specific embodiments of the present disclosure can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:
A data communications system according to one embodiment of the present disclosure is illustrated schematically in
The flexible dielectric waveguide cable 30 comprises one or more exposed dielectric faces that are described in further detail below and are generally configured to transmit electromagnetic millimeter wave radiation originating from the submersible home vessel 10 or the submersible satellite vessel 20. The submersible home vessel 10 illustrated in
The submersible home vessel 10 further comprises a connector coupling portion 14 that is configured to secure an exposed dielectric face of the cable 30 in a position that enables the transmission of unguided millimeter wave radiation across the functionally transparent pressure boundary 12 to a MMW detector 16 within the submersible home vessel. The submersible satellite vessel 20 may also comprise a transparent pressure boundary, connector coupling portion, and MMW detector.
In the embodiment illustrated in
For the purposes of describing and defining the present invention, it is noted that an “exposed” dielectric face is exposed to the ambient prior to coupling with a MMW receiving element, such as a complementary MMW connector or a transparent pressure boundary. It is contemplated that the degree or duration of exposure may vary from a relatively brief, partial exposure to a relatively extended, full exposure. In any case, the exposure will be sufficient for elements in the ambient, e.g., water, sea water, bio-contaminants, etc., to reach the dielectric face prior to coupling with the MMW receiving element.
In
As is illustrated schematically in
As is illustrated in
As is illustrated in
Electromagnetic waves in the millimeter wave region can be conveyed through dielectric transmission lines. Such transmission lines utilize dielectric materials either partially or entirely as the medium for conveying the electromagnetic waves. The flexible dielectric waveguide cable 30 illustrated in
The conditions for single-mode waveguide operation of a flexible dielectric waveguide cable according to the present disclosure can be represented as follows for a given core diameter:
where co is the speed of light in a vacuum, Vc (2.405) is the unit-less single-mode waveguide cutoff parameter (e.g., Vc=2.405), f is the frequency of operation, and εcore and εclad are the core and cladding relative permittivities, respectively. For example, a dielectric waveguide with a core permittivity of 4 is single-mode for core a diameter of 1.5 mm within W-band operating frequencies (75 GHz to 110 GHz). Beam propogation modeling reveals that the MMW field of flexible dielectric waveguide cables according to the present disclosure will extends to a diameter of about 8 mm Therefore, a single dielectric cable could be formed with multiple cores spaced at a pitch of 8 mm
Referring to
It is also contemplated that a variety of alternative cable configurations can be practiced within the spirit of the present disclosure including, but not limited to, the configurations illustrated in
Turning to the construction of the flexible dielectric waveguide cable 30, it is contemplated that the cable core 32 may comprise ceramic particles dispersed in a dielectric matrix. For example, the dielectric matrix may comprise a relatively low permittivity material selected from PTFE, polystyrene, polyethylene, and combinations thereof. The ceramic particles may comprise a relatively high permittivity material selected from alumina, lithium niobate, silicon, and combinations thereof. In practice, the ceramic particles occupy between approximately 5 wt % and approximately 20 wt % of the cable core and are preferably characterized by an average maximum dimension that is less than approximately 10% of the wavelength of the electromagnetic millimeter wave radiation. For example, when the electromagnetic millimeter wave radiation comprises a 300 GHz signal characterized by a wavelength of 1 mm, the ceramic particles preferably exhibit an average maximum dimension of less than 100 um. Similarly, for a 94 GHz signal characterized by a wavelength of 3.3 mm, the ceramic particles preferably exhibit an average maximum dimension of less than 330 μm.
More specifically, in one embodiment, the cable core 32 is constructed by dispersing 18 wt % alumina (ε=9.8) in a PTFE matrix (ε=2.1) to achieve a resulting core permittivity of approximately 3.5. The core diameter is approximately 2 mm and the cladding is 100% PTFE defining a diameter of about 10 mm In practicing the concepts of the present disclosure, it is noted that respective components of the core and cladding can be controlled to vary the resulting core and cladding dimensions and permittivity.
For the purposes of describing and defining the present invention, it is noted that reference herein to a “millimeter” wave is intended to encompass electromagnetic radiation in the highest radio frequency band, i.e., from about 30 to about 300 gigahertz, also referred to as terahertz radiation. This band has a wavelength of ten to one millimeter, giving it the name millimeter band or millimeter wave, sometimes abbreviated MMW or mmW.
The MMW detector 16 is illustrated schematically in
Schottky-diode-based millimeter-wave detector downstream of the preamplifier. Signal processing can be enabled by providing a clock and data recovery circuit.
For the purposes of describing and defining the present invention, it is noted that reference herein to a variable being a “function” of a parameter or another variable is not intended to denote that the variable is exclusively a function of the listed parameter or variable. Rather, reference herein to a variable that is a “function” of a listed parameter is intended to be open ended such that the variable may be a function of a single parameter or a plurality of parameters.
It is also noted that recitations herein of “at least one” component, element, etc., should not be used to create an inference that the alternative use of the articles “a” or “an” should be limited to a single component, element, etc.
It is noted that recitations herein of a component of the present disclosure being “configured” in a particular way, to embody a particular property, or to function in a particular manner, are structural recitations, as opposed to recitations of intended use. More specifically, the references herein to the manner in which a component is “configured” denotes an existing physical condition of the component and, as such, is to be taken as a definite recitation of the structural characteristics of the component.
It is noted that terms like “preferably,” “commonly,” and “typically,” when utilized herein, are not utilized to limit the scope of the claimed invention or to imply that certain features are critical, essential, or even important to the structure or function of the claimed invention. Rather, these terms are merely intended to identify particular aspects of an embodiment of the present disclosure or to emphasize alternative or additional features that may or may not be utilized in a particular embodiment of the present disclosure.
For the purposes of describing and defining the present invention it is noted that the terms “substantially” and “approximately” are utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The terms “substantially” and “approximately” are also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.
Having described the subject matter of the present disclosure in detail and by reference to specific embodiments thereof, it is noted that the various details disclosed herein should not be taken to imply that these details relate to elements that are essential components of the various embodiments described herein, even in cases where a particular element is illustrated in each of the drawings that accompany the present description.
Rather, the claims appended hereto should be taken as the sole representation of the breadth of the present disclosure and the corresponding scope of the various inventions described herein. Further, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. More specifically, although some aspects of the present disclosure are identified herein as preferred or particularly advantageous, it is contemplated that the present disclosure is not necessarily limited to these aspects.
It is noted that one or more of the following claims utilize the term “wherein” as a transitional phrase. For the purposes of defining the present invention, it is noted that this term is introduced in the claims as an open-ended transitional phrase that is used to introduce a recitation of a series of characteristics of the structure and should be interpreted in like manner as the more commonly used open-ended preamble term “comprising.”
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2010/025483 | 2/26/2010 | WO | 00 | 9/7/2011 |
Number | Date | Country | |
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61155768 | Feb 2009 | US |