Abstract: Tethered Unmanned Aircraft Antenna utilizing a Vertical Take Off and Landing (VTOL) Unmanned Aerial System (UAS) which may be provided by quadcopter drone (for example) constrained by a tether connected at one end to a maritime or land-based platform, the tether also being used as a RF antenna. The tether is capable of transmitting DC power to the UAS or drone at a desired antenna height and simultaneously supports RF transmission power with the help of a DC power isolation circuit. The tether is desirously lightweight and corona resistant.

Abstract: A system for subsurface transmission includes an array of very low frequency (VLF) transmitter nodes supported by semi-autonomous maritime, airborne, or space platforms spaced at regular intervals from their nearest neighbors and phased to localize VLF coverage to some desired area on a body of water.

Abstract: A method and an apparatus for coupling two nonlinear resonators via a nonlinear element to generate phononic frequency combs.

Abstract: A method, apparatus, system, and computer program product for evaluating a maturity of a model for a product. A selected maturity state is determined by a computer system for the model for evaluation. A determination is made by the computer system as to whether the model meets a set of criteria for the selected maturity state and a confidence level for the selected maturity state. A model action is performed by the computer system using the model when the model meets the set of criteria for the selected maturity state and the confidence level for the selected maturity state.

Abstract: An electronically steerable phased array and switching network connected to an FMCW radar transceiver to enable a low-cost monopulse tracking system that covers a wide field of regard using electronic beam steering. In a first mode, beamformer integrated circuits (BFICs) at each element in the array are switched synchronously with transmit/receive (T/R) switches located at the subarray level. This allows the entire aperture to be switched between transmission and reception, enabling the FMCW radar transceiver to be operated in a pulsed configuration. In a second mode, a portion of the T/R switches at the subarray level and all of the connecting BFICs at the element level are fixed in either transmitting or receiving mode, allowing separate portions of the aperture to concurrently transmit or receive. The arrangement of transmitting and receiving subarrays can be dynamically reconfigured to allow for accurate bearing and azimuth estimation using alternating monopulse.

Abstract: A system for subsurface transmission includes an array of very low frequency (VLF) transmitter nodes supported by semi-autonomous maritime, airborne, or space platforms spaced at regular intervals from their nearest neighbors and phased to localize VLF coverage to some desired area on a body of water.

Abstract: A comb enhanced oscillator in which a drive signal from a first oscillator is split into two signals. The first signal is applied to a nonlinear resonator producing a phononic frequency comb of equally spaced resonances. The second signal is passed through an amplitude detector and a phase shifter. In one embodiment, the comb is applied to the phase shifter to correct for AM-PM cross-correlation noise and then applied to a phase lock loop (PLL) for locking to a second oscillator. The output of the second oscillator is used as the output of the comb enhanced oscillator.

Abstract: An array of preferably electrically small scatterers is spaced at more or less regular intervals from a central transmitter. Each scatterer element includes a tunable or static reactive load which allows the propagation and fields generated by the central transmitter to be precisely controlled. Each scatterer element in the array also includes a resistive element whose value may change as a function of a distance between each scatterer and the central transmitter and which typically increases as a function of that distance. The central transmitter in the array nominally comprises an antenna, matching network, RF driver, and a vehicle, which may be a maritime vehicle or platform. The antenna for this transmitter may be comprised of an electrically small monopole oriented normal to the surface of the ocean or an electrically small loop antenna oriented with its magnetic moment parallel to the surface of the ocean.

Abstract: A method and apparatus for enhancing the sensitivity of an oscillator circuit functioning, in use, to sense changes in the inductance of inductive elements and/or the capacitance of capacitive elements coupled to said oscillator circuit. The oscillator circuit is coupled to a nonlinear resonator for generating a comb of frequencies in response to a drive frequency generated by the oscillator circuit, the comb of frequencies having at least a portion of at least one tooth for which an absolute value of the first derivative of the drive frequency with respect to said comb frequency is less than 1.0, comparing an output of the nonlinear resonator with an output of a reference oscillator for detecting changes in the drive signal of the oscillator circuit as enhanced by the slope of the at least a portion of at least one tooth for which the absolute value of the first derivative of the drive frequency with respect to said comb frequency is less than 1.0.

Abstract: An energy conversion device disposed in series with an RF driver circuit and an RF antenna, the energy conversion device being arranged to convert a portion of available RF power from the RF driver circuit into a different form of energy (direct current, thermal, or higher frequency electromagnetic waves such as light) which is converted, if needed, to DC and stored in an energy storage device coupled with the RF driver circuit for supplying recycled electrical energy thereto. The RF antenna may be an electrically small antenna and thus a antenna matching network may be provided between the RF driver circuit and the RF antenna. The energy conversion device may comprise, for example, (i) a transformer in combination with a rectifying circuit, (ii) a full wave rectifier, (iii) a half wave rectifier, (iv) a heat and/or light producing device, an energy converter (such as a generator) or a combination of the foregoing.

Abstract: A differential gradiometer comprising a substrate with at least a pair of resonators disposed thereon, wherein each of the at least a pair of resonators is sensitive to environmental factors which produces differential strains between the resonators, a first one of said pair of resonators being connected with a circuit for forming a first oscillator, the second one of said pair of resonators being connected with another circuit for forming a non-linear oscillator, an output of the first oscillator being applied to the non-linear oscillator for generating a comb of frequencies, wherein an addition oscillator is locked to the nth tooth of the comb thereby increasing the sensitivity of the gradiometer by a factor of n.

Abstract: A RF antenna or sensor has a substrate, a resonator operable at UHF disposed on the substrate, the resonator preferably having a quartz bar or body with electrodes disposed on opposing major surfaces thereof and with a magnetostrictive material disposed on or covering at least one of the electrodes. A pair of trapezoidal, triangular or wing shaped high permeability pole pieces preferably supported by that substrate are disposed confronting the resonator, one of the pair being disposed one side of the resonator and the other one of the pair being disposed on an opposing side of said resonator, the pair of high permeability pole pieces being spaced apart by a gap G, the resonator being disposed within that gap G. The size of gap G is preferably less than 100 ?m.

Abstract: A retrofit system applied to existing FMCW radars in order to convert them into pulsed linear frequency-modulated radars with the ability to dynamically switch between two pulsed modes and an FMCW mode based on the estimated range of a target. This retrofit also includes provisions for adaptively configuring chirp and sweep parameters to optimize range resolution. The result is a retrofit system capable of converting an FMCW radar into a dual pulsed mode radar with adaptive sweep configuration.

Abstract: A system for an antenna for very low frequency communication includes a surface platform that is configured to move on a surface or to be stationary on the surface, a first conductive cable having a first end coupled to the surface platform, wherein the first conductive cable is electrically conductive, and an aerial platform coupled to a second end of the first conductive cable, wherein the aerial platform comprises an electrically conductive portion electrically coupled to the first conductive cable, wherein for a moving surface platform the aerial platform is towed and has an elevation above the surface, and wherein for a stationary surface platform the aerial platform flies an orbital path above the surface platform.

Abstract: A system for subsurface transmission includes an array of very low frequency (VLF) transmitter nodes supported by semi-autonomous maritime, airborne, or space platforms spaced at regular intervals from their nearest neighbors and phased to localize VLF coverage to some desired area on a body of water.

Abstract: A method and apparatus for increasing the Signal-to-Noise Ratio (SNR) of phononic comb teeth generated by a non-linear resonator. The method comprises generating a drive signal; applying the drive signal to the non-linear resonator with sufficient gain to generate the phononic comb teeth; and filtering the drive signal before applying it to the non-linear resonator to thereby increase the Signal-to-Noise Ratio (SNR) of phononic comb teeth generated by the non-linear resonator. The apparatus may comprise a circuit including a filter disposed between an oscillator generating the drive signal and the non-linear resonator, the filter preferably having a 3 db passband width which is less than a spacing of the phononic comb teeth generated by the non-linear resonator.

Abstract: A RF antenna comprises a quartz resonator having electrodes disposed thereon with a magnetostrictive film disposed on the quartz resonator either on, partially under or adjacent at least one of the electrodes.

Abstract: A mechanically actuated transmitter is disclosed. The transmitter can comprise a magnetoelastic member; a magnet adjacent to the magnetoelastic member for inducing magnetization in the magnetoelastic member; a mechanical driver for applying mechanical stress to the magnetoelastic material, thereby changing the magnetic permeability of the magnetoelastic material to change an external magnetic field.

Abstract: A RF transmitting device and method for transmitting digital information wherein the device is connected to or connectable with an antenna, the RF transmitting device having an RF source or transmitter, an electronic switch, a plurality electromechanical resonators each connected to the electronic switch. The electronic switch connects a selected one or selected ones of the electromechanical resonators between the RF source or transmitter and the antenna. Alternatively, the electronic switch connects a selected one or selected ones of the electromechanical resonators between different portions of the antenna. The electronic switch is controlled by a digital control unit for causing the electronic switch to couple RF energy produced by the RF source or transmitter to the antenna via the selected one or selected ones of the plurality of electromechanical resonators.

Abstract: A magnetic transmitter including at least one magnetoelastic element, a magnetic field source, and an actuator operably coupled to the magnetoelastic element. The magnetoelastic element is oriented parallel to the magnetic field source. The magnetic field source is configured to induce a magnetic flux in the magnetoelastic element, and the actuator is configured to induce harmonic vibration in the magnetoelastic element. The magnetoelastic element is oriented parallel to the magnetic field source. The harmonic vibration of the magnetoelastic element is configured to change a net magnetic dipole of the magnetic transmitter due to magnetostriction.