Hughes Aircraft Company

International Telephone and Telegraph Corporation

Hughes Electronics Corporation

Other

Raytheon Company

Itt Corporation

Itt Gilfillan, a Division of Itt Corporation

Itt Gilfillan

Hughes Aircraft Company, Hughes Electronics

Ronald I Wolfson

William W Milroy

Joseph P Smalanskas

William G Sterns

George A Hockham

Clifton Quan

Irwin L Newberg

John J Wooldridge

Jeffrey T Nemit

Stuart B Coppedge

Jerome I Glaser

Jan Grinberg

Juan F Lam

Howard S Nussbaum

Richard L Abrams

Louis E Gates, Jr

Mir Akbar Ali

Alan C Lemons

Ruth Ann Mullen

John D Foglesonger

Mike D Thomas

Bobby J Sanders

Michael D Thomas

K C Lim

Donald B Mertens

Donald R Rohweller

Allen M Tran

Shane H Hunter

Ching-Fai Cho

Victor M Petrillo

Methods of fabricating air-dielectric true-time-delay, continuous transverse stub array antenna. The first method uses conventional machining or molding techniques to fabricate layers of plastic with desired microwave circuit features. The plastic layers are then metalized, assembled (aligned) and joined together, such as by using ultrasonic welding techniques. Readily available metalization and ultrasonic welding techniques exist that may be used. The second method uses sheets of metal, into which microwave circuit features are fabricated, such as by machining. The layers are then assembled (aligned) and joined together, using one of several available processes, such as an inert gas, furnace brazing technique, for example.

Methods of fabricating true-time-delay continuous transverse stub array

A planar array antenna having a switching matrix that couples an RF signal to two distributed ferrite scanning line feeds that feed a planar continuous transverse stub array antenna. The scanning line feeds couple RF energy to the antenna from opposite sides to form a total of four beams offset in space that each cover different angular scan sectors. The antenna has reduced complexity and lower design and production costs. The use of dual ferrite scanning line feeds, the switching matrix, and the continuous transverse stub antenna to obtain wide-angle scanning provides significantly improved performance. The present invention uses the two distributed ferrite scanning line feeds to obtain greater scan coverage at upper millimeter-wave frequencies, where realizable ferrite materials are less active and provide diminished scan capability. The scanning line feeds and planar array antenna may be designed so that the four scan sectors are contiguous, to increase the angular scan coverage of the antenna. The switching matrix is used to sequentially feed each of four RF ports, which effectively produces a single beam that scans over the four contiguous scan sectors.

Microwave antenna having wide angle scanning capability

An optical fiber having a conductive layer disposed therearound has sections removed therefrom that form gaps that expose the underlying optical fiber. Light manifolds are formed at each gap, such as are provided by Bragg gratings photoinduced in the core at each gap, and photoconductive material is disposed at each of the gaps. An opaque coating may optionally be disposed over the outside of the photoconductive material to ensure that it is activated by light propagating within the optical fiber. Light transmitted down the fiber may be controllably coupled output of the fiber at each of the gaps. The optical fiber thus provides multiple functions including electrical conductor, light manifold, and substrate on which the photoconductive material is deposited.

Optically reconfigurable conductive line element

A compact scanned antenna which includes a radiator, a rotatable tube and a line source. The radiator is formed by plating a shaped dielectric core. It generates an antenna beam at an output aperture in response to a microwave signal at an input port. The line source generates a radiation sheet which is directed across a signal plane to the input pot. The tube has a cylindrical wall which is positioned across the signal plane. As the tube rotates, refractive or diffractive transmission structures pass through the signal plane. The refractive structures include linear segments which refract the wavefront of the radiation sheet. Because the wavefront slope at the radiator's aperture is a function of the wavefront slope at its input port, the antenna beam is scanned. The linear contour segments have the same inclination but are not colinear. This arrangement reduces the thickness of the tube wall. Phase coherence is achieved by an appropriate radial spacing of adjacent ends of contour segments. The diffractive structures are arranged to vary the spacing of diffraction rings as they pass through the signal plane. This produces scanned, first-order antenna beams. The line source is adapted to direct a predetermined one of these beams into the radiator.

Scanned antenna system and method

Spatial thinning in no more than two dimensions is used in order to lower both the effective dielectric constant and the dielectric loss tangent of ferroelectric ceramics, while retaining a substantial fraction of their tunability. By not thinning in the third direction, along which the dc bias field is applied, the ferroelectric material maintains the connectivity between elements of the ferroelectric structure that is essential to retaining the tunability. Examples of one-dimensional structures (30) include small diameter columns (28, 32) of dielectric material embedded in a dielectric matrix (26, 34). Examples of two-dimensional structures (21) include square (22) and hexagonal (24) cells comprised of ferroelectric material filled with inert dielectric material or vice versa.

Enhanced tunability for low-dielectric-constant ferroelectric materials

A broadband antenna system utilizes multiple photonic bandgap crystals to achieve nearly 100 percent power efficiency over a larger range of frequencies than prior antenna systems. Multiple custom tailored photonic bandgap crystals form a substrate for the antenna system. Each of the crystals is designed to cover a specific range of frequencies. The multiple crystals are attached together to form a photonic bandgap substrate whose bandwidth varies as a function of location on the substrate. A broadband antenna that can cover a wide frequency range, and whose active region shifts to different portions of the antenna as a function of frequency, is formed on the substrate such that the active region of the antenna is always on a crystal that has a corresponding operating bandwidth. The photonic bandgap crystals provide a nearly 100 percent efficient reflector for radiation emitted into the substrate that would otherwise be trapped or dissipated therein.

Efficient broadband antenna system using photonic bandgap crystals

A dielectric material having a dielectric constant which varies inversely with frequency, and preferably with the second power of frequency, fills the space between a radiator and a reflecting groundplane. The back-directed wave is reflected back to the radiator in phase with the directly radiated wave over a wide frequency band, increasing the radiator efficiency.

Radiator bandwidth enhancement using dielectrics with inverse frequency

An electronic device operating in the microwave frequency range having components disposed in a plurality of planes, wherein the planes are stacked vertically. The electronic device is a T/R module or element forming a part of a subarray used in an active array radar. The T/R module or element comprises a transmit chip, a receive chip, low noise amplifiers, a phase shifter, an attenuator, switches, dc power supply, interconnects that interconnect the foregoing components and logic circuits to control the foregoing components. The components when stacked in a 3-D package are disposed behind a radiator or antenna, which transmits and receives the microwave signals. Behind the T/R module or element is a manifold which provides input and output to and from the T/R module or element. The microwave chips of the T/R module are monolithic microwave integrated circuit chips and control logic, which are disposed in an aluminum nitride substrate and coated with a conformal hermetic coating. The 3-D chip package can optionally include micro channel cooling by adding additional layers. The integrated circuits also employ a flip chip design for mounting to the wafers. Optional photonic interconnects could be used for communication between levels in the 3-D package and can be used between subarrays as a manifold.

Small manufacturable array lattice layers

A length of strip transmission line uses two symmetrically spaced center conductors between two groundplanes. These conductive strips produce an even-mode electric field between the two groundplanes when excited in-phase and an odd-mode electric field when excited in anti-phase relationship. For the latter case, the phase velocity of the odd-mode is significantly affected by the electric field in the gap region between the conducting strips. By varying the relative dielectric constant of a material located in the gap region, e.g., by means of a voltage-controllable dielectric such as barium-titanate compositions, the phase velocity and, hence, the phase shift of an RF signal propagating through the strip transmission medium can be controlled.

Phase shift device using voltage-controllable dielectrics

A true time delay phased array is provided which includes a digital subarray interface in the transmit signal path. The digital transmit signal path interface includes a digital reference signal generation means and digital signal propagation means for supplying the digital reference signal to the subarray. Each subarray includes RF carrier signal generating means for generating an RF carrier signal phase coherent with the reference signal, a fiber optic true time delay circuit for applying an appropriate phase delay to the RF carrier and an appropriate true time delay to the modulation signal, and a waveform modulator for modulating the modulating signal onto the phase locked RF carrier signal to provide the transmit signal for the subarray. The present invention can be used in conjunction with existing digital interface technology for receive and control signal paths to provide an entirely digital subarray signal path interface.

Optoelectronic phased array with digital transmit signal interface

This invention discloses an antenna element (12) or an array of antenna elements (52) for use in multifunctional systems which exhibits wide bandwidth, small size, polarization diversity and conformality. In one preferred embodiment, an array of circular conductive patches (56,58) are formed on a dielectric substrate (54) in which adjacent patches are formed on opposite sides of the substrate (54). Each of the opposite conducting patches (56,58) are configured to form a dual flared slotline such that an electric field created between the two conductive patches (56,58) will exhibit a wide range of impedance matching to free space. By exciting the conductive patches (56,58), radiating electromagnetic waves having a polarization with respect to the orientation of the slotlines is produced. By this, a single array of antenna elements (52) can be used in a multifunctional system.

Wideband arrayable planar radiator

A structure integrity monitoring apparatus and method for use with certain structures such as air-frame structures. A meandering transmission line (22) or serpentine coaxial cable is adhered to a dielectric substrate (20). The dielectric substrate may be a composite panel of the air-frame structure. A microwave signal is introduced at one end of the transmission line (22) or coaxial cable and absorbed at the other end by an appropriate signal absorbing device. For use of the meandering transmission line (22), generally two conductors (22, 24) are affixed on opposite sides of the dielectric substrate (20). In this manner, an electric field created by the two conductors (22, 24) by the microwave signals propagating through them is confined within the dielectric substrate (20). As the signals travel down the transmission conductors (22, 24), they will be reflected at crossover points along the way creating a signature reflection wave. If the dielectric substrate is flawed, a perturbation in the electric field caused by the flaw will create a reflection of the microwave signal at the flaw area. When this reflection signal is compared with the signature signal, it can be determined where and if a flaw is present.

Detection and ranging of material flaws using microwave transmission

A switched loop/180.degree. phase shift device is disclosed, having the additional capability of an aperture shutter that can be selected to produce either a noncorrelated reflection in one mode of operation, or to absorb RF energy that enters the radiating aperture port in the other mode.

Switched-loop/180 degree phase bit with aperture shutter capabilities

An improved serpentine feed and method of making same. The invention includes a block of conductive material having a primary microwave waveguide channel and at least one secondary channel. Each secondary channel has at least one broadwall common to the primary channel. A high performance coupler is provided in the common broadwall by which microwave energy communicates from the primary channel to the secondary channel. The claimed method of the invention includes the steps of (a) machining mating halves of a first elongated channel into first and second blocks of conductive material; then, (b) machining mating halves of a plurality of second channels into the first and second blocks longitudinally parallel with at least a portion of the halves of the first channel thereby providing a plurality of common broadwalls between the first channel and each of the second channels; next, (c) machining a plurality of slots in each of the common broadwalls between selective first and second channels; and finally, (d) either mechanically fastening or bonding the first and second blocks in alignment such that halves of the first and second channels mate to provide primary and secondary microwave waveguides respectively.

Serpentine feeds and method of making same

An antenna element including a microstrip radiating element having a microstrip feed line and a ground plane on opposite sides of a substrate, with at least one of a plurality as resonators on the same side of the substrate as the microstrip feed line, and a dipole radiator having an increased bandwidth and insulated from the feed line and from the plurality of resonators.

Growing community of inventors

Los Angeles, CA, United States of America

Ronald I Wolfson