Abstract: The system and method for chromatic correlation interferometry direction finding (CIDF) used to resolve ambiguities. Ambiguities are overcome by correlating over a range of frequencies. In some cases, multiple (i.e., 2 or more) frequencies or a continuous range of frequencies are used to make a more robust correlation manifold. As the complex response manifold is frequency dependent, using a set of two or more manifolds provides a significant reduction of false peaks.

Abstract: Techniques are provided for fabricating a low profile antenna that operates with increased efficiency. An antenna implementing the techniques according to an embodiment includes a first arm comprising a first spiral portion and a first rectilinear portion, and a second arm comprising a second spiral portion and a second rectilinear portion. The second spiral portion is concentric with the first spiral portion. The antenna further includes an insulator to separate the arms. The insulator and the arms are planar surfaces disposed within a rectangular region. The first rectilinear portion is adjacent to a first and second side of the perimeter of the rectangular region, and the second rectilinear portion is adjacent to a third and fourth side of the perimeter of the region. The antenna is fabricated as a printed circuit board which is mounted on the fuselage of an aircraft, which serves as a ground plane for the antenna.

Abstract: An antenna module configured for use on an underwater vehicle is disclosed. The antenna module includes an array of spiral antennas fabricated on a multi-layer substrate that provides wide-band RF communication with direction finding (DF) capability. The antenna module can also include other antennas fabricated on the same multi-layer substrate, such as one or more global positioning system (GPS) receivers, an ultra-high frequency/very-high frequency (UHV/VHF) antenna, or one or more iridium antennas. The antenna module may further include a water-proof housing that is coupled to the outside hull of an undersea vehicle via a coupling mechanism. The coupling mechanism allows the antenna module to rotate between a stowed position against the hull and a deployed position that extends the antennas out away from the undersea vehicle. The antenna module is curved or flexible so it can stow against a corresponding curved hull of the undersea vehicle.

Abstract: An antenna module configured for use on an underwater vehicle is disclosed. The antenna module includes an array of spiral antennas fabricated on a multi-layer substrate that provides wide-band RF communication with direction finding (DF) capability. The antenna module can also include other antennas fabricated on the same multi-layer substrate, such as one or more global positioning system (GPS) receivers, an ultra-high frequency/very-high frequency (UHV/VHF) antenna, or one or more iridium antennas. The antenna module may further include a water-proof housing that is coupled to the outside hull of an undersea vehicle via a coupling mechanism. The coupling mechanism allows the antenna module to rotate between a stowed position against the hull and a deployed position that extends the antennas out away from the undersea vehicle. The antenna module is curved or flexible so it can stow against a corresponding curved hull of the undersea vehicle.

Abstract: An endfire antenna structure is disclosed that is for use on aerodynamic systems. The antenna structure includes a first layer of patterned metal, a second layer of patterned metal, and a stack of material layers that includes the first layer of patterned metal and the second layer of patterned metal. The first layer of patterned metal includes a plurality of parallel slots etched through the metal. The second layer of patterned metal includes a tapered radio frequency (RF) feedline having a narrow end coupled to an input/output (I/O) antenna connection. The second layer of patterned metal is aligned over the first layer of patterned metal such that the tapered RF feedline has a length that extends across the plurality of parallel slots. The stack of material layers is flexible such that the stack of material layers is configured to wrap at least partially around the fuselage of an aerodynamic system.

Abstract: Techniques are provided for fabricating a low profile antenna that operates with increased efficiency. An antenna implementing the techniques according to an embodiment includes a first arm comprising a first spiral portion and a first rectilinear portion, and a second arm comprising a second spiral portion and a second rectilinear portion. The second spiral portion is concentric with the first spiral portion. The antenna further includes an insulator to separate the arms. The insulator and the arms are planar surfaces disposed within a rectangular region. The first rectilinear portion is adjacent to a first and second side of the perimeter of the rectangular region, and the second rectilinear portion is adjacent to a third and fourth side of the perimeter of the region. The antenna is fabricated as a printed circuit board which is mounted on the fuselage of an aircraft, which serves as a ground plane for the antenna.

Abstract: A system and method for rank estimation of electromagnetic emitters is provided. One exemplary feature of the system and method includes the use of a Fixed Sigma Gaussian Mixture Model (FSGMM) to determine a rank estimation of electromagnetic emitters. Another exemplary feature of the system and method includes the use of a Gaussian Mixture Model (GMM) clustering approach in conjunction with an Akaike Criterion Information (AIC) to determine a number of clusters and associated statistics of emitters.

Abstract: The system and method for a low profile high gain dual polarization UHF/VHF antenna. In some cases a spiral antenna over a small cavity, with arms attached on either side is provided. The antenna structure is a short distance above a ground plane (e.g., less than 1/10 wavelength at the high frequency of operation). The arms are terminated to ground and the values of the terminations can vary depending on installation and the value chosen for the spiral termination. In some cases, the spiral antenna is not limited to a two arm spiral only as any type of spiral antenna may be used.

Abstract: The system and method for a low profile high gain dual polarization UHF/VHF antenna. In some cases a spiral antenna over a small cavity, with arms attached on either side is provided. The antenna structure is a short distance above a ground plane (e.g., less than 1/10 wavelength at the high frequency of operation). The arms are terminated to ground and the values of the terminations can vary depending on installation and the value chosen for the spiral termination. In some cases, the spiral antenna is not limited to a two arm spiral only as any type of spiral antenna may be used.

Abstract: A dual mode array antenna including a ground plane, a plurality of antenna elements, a tuning mechanism for tuning the array antenna to a resonant frequency, and a base defining a cavity having a depth that is less than half of a wavelength at an upper frequency of the array antenna is disclosed. Each of the plurality of antenna elements includes at least one spiral arm and each of the plurality of antenna elements is embedded in the cavity. The dual mode array antenna operates between the upper frequency and a lower frequency and may operate in one or more resonant frequencies.

Abstract: A dual mode array antenna including a ground plane, a plurality of antenna elements, a tuning mechanism for tuning the array antenna to a resonant frequency, and a base defining a cavity having a depth that is less than half of a wavelength at an upper frequency of the array antenna is disclosed. Each of the plurality of antenna elements includes at least one spiral arm and each of the plurality of antenna elements is embedded in the cavity. The dual mode array antenna operates between the upper frequency and a lower frequency and may operate in one or more resonant frequencies.

Abstract: A system and method for rank estimation of electromagnetic emitters is provided. One aspect of the disclosure provides creating a graph of angles of arrival (AoAs) versus range and using a polynomial curve fit against the graph to determine a rank estimation of electromagnetic emitters. Another aspect of the disclosure provides using a search over parameters of the multiple polynomial curve fits, for each hypothesized rank, to optimize the rank estimation results. This search may be a greedy search to improve speed of convergence. Another aspect of the disclosure provides a metric ‘score’ to select the highest probability rank (number of emitters) based on the agreement between the multiple polynomial curve fits and residual AoA errors.

Abstract: A system and method for rank estimation of electromagnetic emitters is provided. One exemplary feature of the system and method includes the use of a Fixed Sigma Gaussian Mixture Model (FSGMM) to determine a rank estimation of electromagnetic emitters. Another exemplary feature of the system and method includes the use of a Gaussian Mixture Model (GMM) clustering approach in conjunction with an Akaike Criterion Information (AIC) to determine a number of clusters and associated statistics of emitters.

Abstract: A Radio Frequency Identification (RFID) device antenna has a feed region of interdigitated fingers. The interdigitated fingers have parallel centerlines and are spaced one from another. A chip having opposing ends overlays opposing interdigitated fingers. A coupling is established between the chip and the antenna at the interdigitated fingers.

Abstract: The invention provides an actuator apparatus and method where a source provides electrons to a target material wherein electrical work is performed. A beta emission process comprises a source material emitting electrons which are then captured by a target material. The actuator's source vanes rotate within an electric field between the target chutes' walls, generating torque. The principal providing torque and power is the change in energy as a vane gets closer to the outer walls. During the release and capture process, electrical work is performed which, in turn, is transferred into mechanical work in the form of rotation of the rotor. Specific applications include a radioisotope fueled rotary actuator for micro and nano air vehicles employed as the main form of propulsion.

Abstract: A convenient handheld locator is provided for locating an item in an urban environment in which the locator is programmed to search for and locate specific items, with the detected item being displayed on the locator as to its identity or name, also displaying where the item is relative to the locator, as to position and range.

Abstract: A convenient handheld locator is provided for locating an item in an urban environment in which the locator is programmed to search for and locate specific items, with the detected item being displayed on the locator as to its identity or name, also displaying where the item is relative to the locator, as to position and range.

Abstract: The invention provides an actuator apparatus and method where a source provides electrons to a target material wherein electrical work is performed. A beta emission process comprises a source material emitting electrons which are then captured by a target material. The actuator's source vanes rotate within an electric field between the target chutes' walls, generating torque. The principal providing torque and power is the change in energy as a vane gets closer to the outer walls. During the release and capture process, electrical work is performed which, in turn, is transferred into mechanical work in the form of rotation of the rotor. Specific applications include a radioisotope fueled rotary actuator for micro and nano air vehicles employed as the main form of propulsion.

Abstract: A convenient handheld locator is provided for locating an item in an urban environment in which the locator is programmed to search for and locate specific items, with the detected item being displayed on the locator as to its identity or name, also displaying where the item is relative to the locator, as to position and range.

Abstract: A convenient handheld locator is provided for locating an item in an urban environment in which the locator is programmed to search for and locate specific items, with the detected item being displayed on the locator as to its identity or name, also displaying where the item is relative to the locator, as to position and range.