Abstract: The present invention generally relates to an electromagnetic field vector sensing receive antenna array system for installation and deployment on a structure. A multipolarized array of collocated antenna elements is used to provide calibrated amplitude and phase radiation patterns with monopole, dipole, and loop modes generated from crossed loops connected to a beamformer. The invention has applications for installation and deployment on a tower, balloon, satellite for radio frequency sensing and location of low-frequency galactic emissions. The novel receive antenna array system comprises a multipolarized vector sensor antenna array. The disclosed direction-finding vector sensor can be installed and deployed on a structure and can detect and locate radio frequency emissions from galactic sources. The key system components of the receive antenna array system consist of deployable antennas, receivers, signal processing computer, and communications link.

Abstract: The present invention generally relates to an electromagnetic field vector sensing receive antenna array system for installation and deployment on a structure. A multipolarized array of collocated antenna elements is used to provide calibrated amplitude and phase radiation patterns with monopole, dipole, and loop modes generated from crossed loops connected to a beamformer. The invention has applications for installation and deployment on a tower, balloon, satellite for radio frequency sensing and location of low-frequency galactic emissions. The novel receive antenna array system comprises a multipolarized vector sensor antenna array. The disclosed direction-finding vector sensor can be installed and deployed on a structure and can detect and locate radio frequency emissions from galactic sources. The key system components of the receive antenna array system consist of deployable antennas, receivers, signal processing computer, and communications link.

Abstract: The present invention generally relates to an electromagnetic field vector sensing receive antenna array system for installation and deployment on a structure. A multipolarized array of collocated antenna elements is used to provide calibrated amplitude and phase radiation patterns with monopole, dipole, and loop modes generated from crossed loops connected to a be beamformer. The invention has applications for installation and deployment on a tower, balloon, or satellite for radio frequency sensing and location of low-frequency galactic emissions. The novel receive antenna array system comprises a multipolarized vector sensor antenna array. The disclosed direction-finding vector sensor can be installed and deployed on a structure and can detect and locate radio frequency emissions from galactic sources. The key system components of the receive antenna array system consist of deployable antennas, receivers, signal processing computer, and communications link.

Abstract: A method of obtaining an absolute time reference for a high-frequency (HF) sounding signal includes transmitting a reference signal at a first location and transmitting a sounding signal in close proximity to the transmitting of the reference signal at the first location. The method additionally includes receiving the reference signal at a second location and receiving the sounding signal at the second location. The method further includes determining a relative delay at the second location of the sounding signal in relation to the reference signal. The method also includes determining a propagation mode based upon the relative delay. The method additionally includes determining an absolute time reference based upon the propagation mode being observed. Additional methods and associated systems for implementing the methods are also provided.

Abstract: A matching technique that may be used with electrically small antennas uses one or more digital circuit blocks connected in a feedback arrangement configured to tune the transfer function response between the antenna and an output port of the system. Each circuit block may include an analog-to-digital converter (ADC), a digital filter, and a digital-to-analog converter (DAC). As such, tuning the transfer function may be achieved by sensing a voltage or current at various circuit nodes using one or more ADCs, filtering the measurements in response-shaping digital filters, and using one or more DACs to drive other circuit nodes in a manner that elicits a desired circuit response. Techniques are provided for allowing a matched antenna to adapt to a changing environment about the antenna. In one illustrative embodiment, the digital circuit blocks may be provided as digital non-Foster circuit blocks.

Abstract: The present invention generally relates to an electromagnetic field vector sensing receive antenna array system for installation and deployment on a structure. A multipolarized array of collocated antenna elements is used to provide calibrated amplitude and phase radiation patterns with monopole, dipole, and loop modes generated from crossed loops connected to a be informer. The invention has applications for installation and deployment on a tower, balloon, or satellite for radio frequency sensing and location of low-frequency galactic emissions. The novel receive antenna array system comprises a multipolarized vector sensor antenna array. The disclosed direction-finding vector sensor can be installed and deployed on a structure and can detect and locate radio frequency emissions from galactic sources. The key system components of the receive antenna array system consist of deployable antennas, receivers, signal processing computer, and communications link.

Abstract: A matching technique that may be used with electrically small antennas uses one or more digital circuit blocks connected in a feedback arrangement configured to tune the transfer function response between the antenna and an output port of the system. Each circuit block may include an analog-to-digital converter (ADC), a digital filter, and a digital-to-analog converter (DAC). As such, tuning the transfer function may be achieved by sensing a voltage or current at various circuit nodes using one or more ADCs, filtering the measurements in response-shaping digital filters, and using one or more DACs to drive other circuit nodes in a manner that elicits a desired circuit response. Techniques are provided for allowing a matched antenna to adapt to a changing environment about the antenna. In one illustrative embodiment, the digital circuit blocks may be provided as digital non-Foster circuit blocks.

Abstract: A method of obtaining an absolute time reference for a high-frequency (HF) sounding signal includes transmitting a reference signal at a first location and transmitting a sounding signal in close proximity to the transmitting of the reference signal at the first location. The method additionally includes receiving the reference signal at a second location and receiving the sounding signal at the second location. The method further includes determining a relative delay at the second location of the sounding signal in relation to the reference signal. The method also includes determining a propagation mode based upon the relative delay. The method additionally includes determining an absolute time reference based upon the propagation mode being observed. Additional methods and associated systems for implementing the methods are also provided.

Abstract: Disclosed is a method and apparatus for determining weld and coil resistances of a commutator type electric motor armature. The method comprises the steps of determining a resistance ratio for a pair of coils and then determining the weld resistance across a commutator bar and coil connection based upon the resistance ratio.