Abstract: Embodiments of systems and method for determining a joint space-time spectral estimate (P) for a wideband spectrum are generally described herein. To determine a joint space-time spectral estimate (P) for a wideband spectrum, a random time delay may be applied to received signals for each channel of a plurality of receive channels to generate time-delayed signals for each receive channel. The time-delayed signals may be sampled for each receive channel to generate time-delayed samples and form array manifold vectors based on the random time delays and position of each antenna element in an array of antenna elements. An inverse (Q) of the joint-space time spectral estimate (P) may be determined by projecting the array manifold vectors through a mixing matrix (M). The mixing matrix (M) may be based on the time-delayed samples. The joint space-time spectral estimate (P) may comprise spatial and temporal properties of the wideband spectrum.

Abstract: Embodiments of systems and method for determining a joint space-time spectral estimate (P) for a wideband spectrum are generally described herein. To determine a joint space-time spectral estimate (P) for a wideband spectrum, a random time delay may be applied to received signals for each channel of a plurality of receive channels to generate time-delayed signals for each receive channel. The time-delayed signals may be sampled for each receive channel to generate time-delayed samples and form array manifold vectors based on the random time delays and position of each antenna element in an array of antenna elements. An inverse (Q) of the joint-space time spectral estimate (P) may be determined by projecting the array manifold vectors through a mixing matrix (M). The mixing matrix (M) may be based on the time-delayed samples. The joint space-time spectral estimate (P) may comprise spatial and temporal properties of the wideband spectrum.

Abstract: A direction finding (DF) system and technique using a switched network architecture to couple a first plurality of antenna elements to a second, fewer, plurality of channels of an RF receiver. The RF receiver provides signals to a DF processor which combines data sampled at phase centers of the plurality of array elements. Such combined data samples may be used to estimate a direction of a received signal. The antenna elements may be configured into subarrays and a switch network couples different groups of subarrays to the RF receiver channels during different dwell times. Data collected during each dwell may be used to generate a spatial sample covariance matrix (SCM) and multiple spatial SCMs may be combined to provide aggregate covariance matrix values. A DF processor uses values from the aggregate covariance matrix to provide an output signal indicative of the direction of a received signal.

Abstract: The concepts, systems and method described herein provide direction finding (DF) methods based on a minimum distance (MINDIST) search to principal components. In an embodiment, the method includes capturing samples of data from one or more array elements. The samples may be samples of a signal received at the array elements. The method includes generating a spatial sample covariance matrix (SCM) using the samples of data, extracting principal components from the SCM and generating a principal component table using angle and frequency measurement for each of the principal components. The method further includes determining a distance between a test point and each value in the principal component table and identifying a minimum distance point corresponding to a direction of the received signal. The minimum distance point may correspond to direction of arrival of a signal on the one or more array elements.

Abstract: A photonic integrated circuit. The photonic integrated circuit includes: a plurality of antenna elements, an element of the plurality of antenna elements having an electrical port and including: a first laser configured to produce laser light of a first wavelength; and a first radiative patch conditionally connected to the electrical port and connected, by an optical connection, to the laser, the first radiative patch including, as a major component, a semiconductor material configured to be conductive when illuminated by light having the first wavelength, and to be nonconductive when not illuminated, the first radiative patch being configured, when conductive, to convert an electric signal received at the electrical port to radiated electromagnetic waves, or to convert received electromagnetic waves to an electrical signal at the electrical port.

Abstract: The concepts, systems and method described herein provide direction finding (DF) methods based on a minimum distance (MINDIST) search to principal components. In an embodiment, the method includes capturing samples of data from one or more array elements. The samples may be samples of a signal received at the array elements. The method includes generating a spatial sample covariance matrix (SCM) using the samples of data, extracting principal components from the SCM and generating a principal component table using angle and frequency measurement for each of the principal components. The method further includes determining a distance between a test point and each value in the principal component table and identifying a minimum distance point corresponding to a direction of the received signal. The minimum distance point may correspond to direction of arrival of a signal on the one or more array elements.

Abstract: In an array antenna having a plurality of subarrays, a direction finding system and technique includes receiving signals at an array antenna and capturing data with a plurality of groups of subarrays. Each group of subarrays may capture data during a selected one of a plurality of different dwell times. The method further includes generating a plurality of dwell spatial sample covariance matrices (SCMs) using data corresponding to one or more of the plurality of groups of subarrays and combining the plurality of dwell spatial SCMs in complex form to generate an aggregate covariance matrix (ACM). The ACM may then be used in subsequent processing with MINDIST technique to estimate a direction of a received signal based on the combined data.

Abstract: In an array antenna having a plurality of subarrays, a direction finding system and technique includes receiving signals at an array antenna and capturing data with a plurality of groups of subarrays. Each group of subarrays may capture data during a selected one of a plurality of different dwell times. The method further includes generating a plurality of dwell spatial sample covariance matrices (SCMs) using data corresponding to one or more of the plurality of groups of subarrays and combining the plurality of dwell spatial SCMs in complex form to generate an aggregate covariance matrix (ACM). The ACM may then be used in subsequent processing with MINDIST technique to estimate a direction of a received signal based on the combined data.

Abstract: The concepts, systems and method described herein provide direction finding (DF) methods based on a minimum distance (MINDIST) search to principal components. In an embodiment, the method includes capturing samples of data from one or more array elements. The samples may be samples of a signal received at the array elements. The method includes generating a spatial sample covariance matrix (SCM) using the samples of data, extracting principal components from the SCM and generating a principal component table using angle and frequency measurement for each of the principal components. The method further includes determining a distance between a test point and each value in the principal component table and identifying a minimum distance point corresponding to a direction of the received signal. The minimum distance point may correspond to direction of arrival of a signal on the one or more array elements.

Abstract: A photonic integrated circuit. The photonic integrated circuit includes: a plurality of antenna elements, an element of the plurality of antenna elements having an electrical port and including: a first laser configured to produce laser light of a first wavelength; and a first radiative patch conditionally connected to the electrical port and connected, by an optical connection, to the laser, the first radiative patch including, as a major component, a semiconductor material configured to be conductive when illuminated by light having the first wavelength, and to be nonconductive when not illuminated, the first radiative patch being configured, when conductive, to convert an electric signal received at the electrical port to radiated electromagnetic waves, or to convert received electromagnetic waves to an electrical signal at the electrical port.

Abstract: A photonic integrated circuit. The photonic integrated circuit includes: a plurality of antenna elements, an element of the plurality of antenna elements having an electrical port and including: a first laser configured to produce laser light of a first wavelength; and a first radiative patch conditionally connected to the electrical port and connected, by an optical connection, to the laser, the first radiative patch including, as a major component, a semiconductor material configured to be conductive when illuminated by light having the first wavelength, and to be nonconductive when not illuminated, the first radiative patch being configured, when conductive, to convert an electric signal received at the electrical port to radiated electromagnetic waves, or to convert received electromagnetic waves to an electrical signal at the electrical port.

Abstract: The concepts, systems and method described herein provide direction finding (DF) methods based on a minimum distance (MINDIST) search to principal components. In an embodiment, the method includes capturing samples of data from one or more array elements. The samples may be samples of a signal received at the array elements. The method includes generating a spatial sample covariance matrix (SCM) using the samples of data, extracting principal components from the SCM and generating a principal component table using angle and frequency measurement for each of the principal components. The method further includes determining a distance between a test point and each value in the principal component table and identifying a minimum distance point corresponding to a direction of the received signal. The minimum distance point may correspond to direction of arrival of a signal on the one or more array elements.

Abstract: In an array antenna having a plurality of subarrays, a direction finding system and technique includes receiving signals at an array antenna and capturing data with a plurality of groups of subarrays. Each group of subarrays may capture data during a selected one of a plurality of different dwell times. The method further includes generating a plurality of dwell spatial sample covariance matrices (SCMs) using data corresponding to one or more of the plurality of groups of subarrays and combining the plurality of dwell spatial SCMs in complex form to generate an aggregate covariance matrix (ACM). The ACM may then be used in subsequent processing with MINDIST technique to estimate a direction of a received signal based on the combined data.

Abstract: A photonic integrated circuit. The photonic integrated circuit includes: a plurality of antenna elements, an element of the plurality of antenna elements having an electrical port and including: a first laser configured to produce laser light of a first wavelength; and a first radiative patch conditionally connected to the electrical port and connected, by an optical connection, to the laser, the first radiative patch including, as a major component, a semiconductor material configured to be conductive when illuminated by light having the first wavelength, and to be nonconductive when not illuminated, the first radiative patch being configured, when conductive, to convert an electric signal received at the electrical port to radiated electromagnetic waves, or to convert received electromagnetic waves to an electrical signal at the electrical port.

Abstract: A hardover protection system for an aircraft. A differential motion sensor is mounted to a sector for receiving cockpit pitch commands input via a cable system. The motion sensor includes a pair of cranks held together by a predetermined spring preload. One of the cranks is coupled to a rod that forms a portion of a power linkage for hydraulically driving an elevator surface while the other is coupled to a rod that is linked to a shutoff valve. A linkage for mechanically driving an elevator control tab is also mounted to the sector. The design of the shutoff valve and its location within the aircraft's hydraulic control system interact to disable powered operation of the elevator surface upon a predetermined degree of deflection of the shutoff valve piston. Such deflection is responsive to the detection of a predetermined mismatch between the input command motion to the sector and the output motion of the power linkage.