Ail Systems, Inc.

Eaton Corporation

Other

Exelis Inc.

All Systems, Inc.

Ronald M Rudish

Scott F Hall

Peter J McVeigh

Joseph S Levy

Edward G Magill

John A Pierro

George Skahill

Brian M Sullivan

Richard L Clouse, Jr

A phased array antenna includes an array of antenna elements configured to transmit signals that form an antenna beam. A corresponding set of amplifiers supplies a respective set of continuous wave (CW) signals to the antenna elements for transmission. The CW signals having respective different frequencies that are offset from each other by incremental offset frequencies such that the different frequencies are spaced over a frequency range at intervals. Phases of the set of CW signals are aligned such that, at periodic instants, all of the CW signals have simultaneous zero crossings. The frequency and phase relationships among the set of CW signals cause the antenna elements to radiate an antenna beam that scans a field of view in a raster pattern. The resulting ultra-fast scan rate effectively delivers short pulses to any given point within the field of view, making the radiated signal suitable for three-dimensional imaging.

Three-dimensional imaging system employing fast-scanned antenna array

A technique for improving impedance matching in a phased array antenna involves placing a segmented fence around the antenna elements of the array. The antenna elements are arranged above a ground surface such as a ground plane. The segmented fence includes spaced-apart conductive projections electrically coupled to and extending from the ground surface, such that the segmented fence partially terminates electric fields traveling in directions parallel to the ground surface. The segmented fence lies in paths extending in at least two directions along the ground surface to define fence enclosures that surround individual antenna elements. With dual-polarization or multi-polarization dipole antenna elements, the fence enclosures partially terminate the electric field in each direction parallel to the ground surface to simplify impedance matching without unduly restricting the magnetic field.

Impedance matching mechanism for phased array antennas

An antenna includes at least two planar conductors cooperatingly arranged in a planar configuration having a bifilar spiral winding structure, a log-periodic structure or a sinuous configuration and a frequency-independent reflective backing situated on one axial side of the planar configuration. The backing includes a solid, disk-shaped dielectric substrate having a relatively high dielectric constant, and three mutually perpendicular arrays of elongated dielectric elements at least partially embedded in the solid dielectric substrate. The elongated dielectric elements have a relatively low dielectric constant. The elongated dielectric elements of the three mutually perpendicular arrays are formed as rods, cones and rings.

High efficiency broadband antenna

An Instantaneous Frequency Measurement (IFM) receiver that receives a signal from a target and determines the frequency of the signal. The IFM receiver includes delay lines selected in lengths forming relatively prime ratios or by using the preferred method of the present invention which minimizes the total number of different delays required to achieve a given accuracy in frequency measurement.

Method for minimizing the number of delay lines required in instantaneous frequency measurement receivers and apparatus which uses same

An integrated receiver includes an Instantaneous Frequency Measurement (IFM) device, an interferometer and switches. The IFM receives signals from a target and determines the frequency of the signals. The IFM includes the shared N-channel phase receiver. The interferometer also receives the signals from the target and determines the angle-of-arrival (AOA) of the signals. The interferometer includes the shared N-channel phase receiver and shares the shared N-channel phase receiver with the IFM. The switches selectively connect the shared N-channel phase receiver to the IFM when the IFM is determining the frequency of the signals, and selectively connect the shared N-channel phase receiver to the interferometer when the interferometer is determining the AOA of the signals. The shared N-channel phase receiver determines phase information indicative of the frequency of the signals and the AOA of the signals. A method for calculating the frequency and the AOA of the signals from the target includes the steps of receiving the signals, determining the frequency of the signals using the shared N-channel phase receiver, and determining the AOA of the signals using the shared N-channel phase receiver.

Integrated interferometer and instantaneous frequency measurement device and method

A virtual beam system operating in an environment, including a non-compatible receiver, includes a transmitting subsystem and a receiving subsystem. The transmitting subsystem includes an array of transmitting elements and an element position encoded composite signal generator for generating an element position encoded composite signal. The array of transmitting elements is operatively coupled to the signal generator. The transmitting subsystem radiates the element position encoded composite signal via the array of transmitting elements. The receiving subsystem is responsive to the element position encoded composite signal and includes a receiving element and an element position encoded composite signal decoder for decoding the element position encoded composite signal. The receiving element is operatively coupled to the signal decoder. The element position encoded composite signal appears to be radiated as a wide beam, with relatively low directive gain, when received and decoded by the non-compatible receiver. Conversely, the element position encoded composite signal appears to be radiated as a narrow beam, with relatively high directive gain, when received by the receiving element and decoded by the signal decoder of the receiving subsystem.

Virtual beam system

A broadband impedance matching circuit employs active circuits featuring non-Foster reactance behavior, such as negative capacitor circuits and negative inductor circuits, to achieve extremely broadband matching of electrically small antennas. The matching circuit includes at least one non-Foster reactance circuit selected to neutralize the reactance exhibited by the antenna. The circuit further includes a dynamic dispersive impedance transformer circuit which compensates for the frequency dependent radiation resistance presented by the electrically small antenna. The dynamic dispersive impedance transformer is constructed using complementary Foster and non-Foster reactance circuits configured as an impedance transformer.

Apparatus and method for broadband matching of electrically small

An antenna and system for determining two-dimensional angle-of-arrival includes circular array interferometers for azimuth, linear interferometers for elevation, and a mast for positioning the interferometers in a vertically stacked orientation. The circular array interferometers exhibit azimuth constant-phase-difference contours orthogonal to elevation constant-phase-difference contours exhibited by the linear interferometers. An antenna and system for determining azimuth of input signals includes ambiguous and non-ambiguous circular array interferometers. The non-ambiguous circular array interferometer resolves ambiguities introduced by the ambiguous circular array interferometer, the at least one ambiguous circular array interferometer operatively coupled to a low-order Butler matrix and power divider/combiner such that a high order Butler matrix is not required to generate omnidirectional phase modes from the ambiguous circular array interferometer. A method for determining phase differences indicative of two-dimensional angle-of-arrival includes determining a first phase difference indicating azimuth using circular array interferometers, determining a second phase difference indicating elevation using linear interferometers, and orienting the interferometers in a vertically stacked orientation such that the azimuth constant-phase-difference contours are orthogonal to the elevation constant-phase-difference contours. A method for determining phase difference representative of azimuth includes determining a phase difference indicative of azimuth using ambiguous circular array interferometer and non-ambiguous circular array interferometers, and resolving ambiguities in azimuth introduced by the ambiguous circular array interferometer using the non-ambiguous circular array interferometer, the at least one ambiguous circular array interferometer operatively coupled to a low-order Butler matrix and power divider/combiner such that a high order Butler matrix is not required to generate omnidirectional phase modes from the ambiguous circular array interferometer. A method for determination of polarization of input signals with only one added element.

Antenna and method for two-dimensional angle-of-arrival determination

A satellite based signal transmission and reception system which generates multiple beams with low side lobes and minimal crossover losses. The system includes a focusing device and an array of signal generator elements coupled to feed radiator elements. The feed radiator elements are assigned into overlapping beam sub-arrays characterized by a frequency and radiated beam polarization. Each overlapping sub-array generates a transmission beam signal which is orthogonally polarized with respect to the beam generated by the other overlapping sub-array. The use of beam orthogonality provides for physically overlapping beam sub-arrays without the use of analog combining networks which are inherently lossy structures. This allows beams to be generated having a highly tapered amplitude distribution to simultaneously achieve low side lobe levels and low beam cross over losses. By employing multiple signal generators driving the transmission elements of the beam sub-arrays, the transmission system is able to step the transmit signals along the feed radiator array to compensate for satellite motion without the use of complex RF switching networks. In an analogous fashion, antenna elements in an array receive multiple transmission beam signals which are incident upon a focusing device. The antenna elements are dynamically assigned to overlapping receive beam sub-arrays which are orthogonally polarized. The multiple beam receiving system is able to step the received signal sub-arrays along the array to compensate for satellite motion.

Multiple beam antenna system and method

A direct digital synthesizer circuit and method for reducing the harmonic content in a synthesized output signal. The direct digital synthesizer generates first and second address signals driving first and second sine look-up read only memory (sine ROM) circuits. The first and second sine ROMs generate first and second digital sine wave signals which are offset in phase from one another by 180 degrees. The first and second digital sine wave signals are converted to first and second analog sine wave signals. The first and second analog sine wave signals are combined in a subtractor circuit. As a result of the phase relationship between the first and second analog sine wave signals, the fundamental component of these signals are emphasized by subtraction while the second harmonic component of theses signals are simultaneously de-emphasized.

Apparatus and method for harmonic reduction in a direct digital

A digitally beam formed phased array antenna capable of both transmitting and receiving signals is constructed from a series of digitally controlled antenna elements. To transmit signals, a series of direct digital synthesizers is used to drive the antenna elements forming the phased array. Each direct digital synthesizer is programmed from a common digital processor with specific time and phase delay information such that the signals from the array combine to form a desired antenna pattern. To receive signals, signals from each antenna element in the phased array are processed by analog to digital converter. The digitized signals are then pre-processed in a time and phase delay preprocessor which receives time and phase delay information from a corresponding direct digital synthesizer prior to signal combining in a common digital processor. The digitally beam formed antenna, thus formed, allows for remote reconfiguration, flexible partitioning, and generation of multiple and independent beams from a single phased array.

Direct digital synthesizer driven phased array antenna

A digitally beam formed phased array antenna capable of both transmitting and receiving signals is constructed from a series of digitally controlled antenna elements. To transmit signals, a series of direct digital synthesizers is used to drive the antenna elements forming the phased array. Each direct digital synthesizer is programmed from a common digital processor with specific time and phase delay information such that the signals from the array combine to form a desired antenna pattern. To receive signals, signals from each antenna element in the phased array are processed by analog to digital converter. The digitized signals are then preprocessed in a time and phase delay preprocessor which receives time and phase delay information from a corresponding direct digital synthesizer prior to signal combining in a common digital processor. The digitally beam formed antenna, thus formed, allows for remote reconfiguration, flexible partitioning, and generation of multiple and independent beams from a single phased array.

A system for increasing the power efficiency of a balanced amplifier driven antenna arrangement includes a push-pull class B power amplifier circuit which is responsive to a periodic, time varying input signal and generates at least two output signals in response thereto. The arrangement also includes a balanced antenna exhibiting a relatively high impedance at the second harmonic of the input signal. The arrangement further includes at least one transmission line operatively coupled between the power amplifier circuit and the balanced antenna to provide the at least two output signals to the balanced antenna. The at least one transmission line has a length which is one-eighth of the wavelength of the input signal or odd multiples thereof, and thereby reflects back to the power amplifier circuit a substantially short circuit at the second harmonic of the input signal.

Growing community of inventors

Commack, NY, United States of America

Ronald M Rudish