Hrl Laboratories, LLC

Gm Global Technolgoy Operations, Inc.

The Boeing Company

Carson R White

Walter S Wall

Hyok Jae Song

Christopher Paul Henry

Daniel J Gregoire

Jonathan James Lynch

Joseph S Colburn

Eray Yasan

Ryan G Quarfoth

James H Schaffner

Donald A Hitko

Michael W Yung

Daniel Yap

Randall Lynn Kubena

Zhiwei A Xu

Kevin Geary

Richard P Berg

Ignacio Ramos

Christopher Stephen Roper

Keyvan R Sayyah

Brian G Hughes

David S Matthews

Susan L Morton

Arthur Bekaryan

Jason W May

Hui Pin Hsu

James H Scaffner

Todd Rork

Nathan R Brooks

Yoon Yeong

Evan Schlomann

Amit Patel

An exemplary receive antenna having a conductive surface. The conductive surface includes an aperture configured to operate as a slot antenna, and one or more amplifiers or buffer amplifiers is electrically connected across the aperture. At least one feed is connected between the one or more amplifiers and the aperture. An input impedance Zof each of the one or more amplifiers at the at least one feed location is lower than 0.5× an impedance of the aperture Zat a first resonance frequency.

Active receive antenna

A spar buoy for very low frequency (VLF) or low frequency (LF) transmission including a first portion of the spar buoy extending above a mean water line including a conductive structure including a coaxial feed, and an antenna coupled to the coaxial feed and extending above the conductive structure, and a second portion of the spar buoy below the mean water line including a transmitter coupled to the coaxial feed, an energy storage subsystem coupled to the transmitter and an electric power generation subsystem coupled to the energy storage subsystem.

Spar transmitter

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.

Tethered unmanned aircraft antenna

A drive circuit with predistortion. In some embodiments, a system includes a signal input, a predistortion circuit, and an amplifier circuit. The predistortion circuit may be operatively coupled to the signal input and to the amplifier circuit and configured to modify a radio frequency (RF) signal received at the signal input to cause the amplifier circuit to drive, into a load connected to the amplifier circuit, a current that is substantially a replica of the input signal.

Drive circuit with predistortion

An antenna system having at least one active element with a first end thereof for connection to a radio receiver, transmitter or transceiver and at least one electromechanical resonator connected in series with (i) at least portion of said at least one active element and at least another portion of said at least one active element or (ii) said at least one active element and said radio receiver, transmitter or transceiver. The at least one active element exhibits capacitive reactance at an intended frequency of operation and the at least one electromechanical resonator exhibits inductive reactance at the intended frequency of operation, the inductive reactance of the at least one electromechanical resonator offsetting or partially offsetting the capacitive reactance of the at least one antenna element at the intended frequency of operation.

Antenna loaded with electromechanical resonators

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.

Distributed semi-autonomous phased arrays for subsurface VLF transmission

An active biconical antenna and a receive array comprising a combination of active biconical and Vivaldi antennas. In one configuration, the active biconical antenna includes upper and lower cones. Each cone has a respective truncated apex. First and second feed points are respectively connected to the truncated apexes of the upper and lower cones and to first and second conductors. The active biconical antenna further includes a buffer amplifier having respective input terminals connected to the first and second conductors. The buffer amplifier has an input impedance that is impedance matched to an antenna impedance at and above but not below a frequency fand is higher than the antenna impedance at frequencies substantially less than f. The buffer amplifier also has an output impedance that is impedance matched to a system impedance at frequencies both above and below f. A length of the first and second conductors is less than a wavelength at the frequency f.

Active biconical antenna and receive array

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.

Array of VLF scatterers for control of electromagnetic wave propagation on the ocean surface

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.

Broadband antenna matching network employing energy recovery schemes

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.

Slanted top loaded monopole for VLF generation

A transmitting circuit. In some embodiment, the transmitting circuit includes a slot antenna and an amplifier. The slot antenna may include a slot in a conductive sheet, and it may have a first resonant frequency, the first resonant frequency being within 20% of a slot frequency which is between a first frequency corresponding, in a first volume, to a wavelength twice the length of the slot, and a second frequency corresponding, in a second volume, to a wavelength twice the length of the slot. The amplifier may be connected to the slot through a connection including a conductive path, between the amplifier and the slot, having a length less than 0.2 times the length of the slot. The magnitude of the output impedance of the amplifier may be less than 0.25 times the magnitude of the impedance of the slot antenna at a first resonant frequency.

Active antenna transmitter

Growing community of inventors

Agoura Hills, CA, United States of America

Carson R White