Abstract: Methods and systems are disclosed for wireless communication, and in particular using a coaxial antenna for distributed wireless transmission. In one example, a wireless transmitter is disclosed that includes a radio frequency signal source and a coaxial cable including a near end and a far end. The near end is electrically connected to the radio frequency signal source and configured to receive signals from the radio frequency signal source. The coaxial cable has an inner conductor and an outer conductor. The wireless transmitter includes a shorting connection at the far end of the coaxial cable, the shorting connection electrically connecting the inner conductor and the outer conductor, and a plurality of openings along the coaxial cable spaced at predetermined locations to output signals generated by the radio frequency signal source. The invention can be used for RF attenuation monitoring and/or testing applications.

Abstract: The present invention relates systems and methods of electromagnetic protection for integrated video and electromagnetic detector security system equipment. A security system configured to be protected from electromagnetic events or attacks includes a quantity of video cameras and a quantity of electromagnetic event detectors disposed at a facility. The system also includes an electromagnetically-shielded cabinet containing computing equipment and a storage media. The electromagnetically-shielded cabinet is configured to receive data from each of the quantity of video cameras and electromagnetic detectors and store the data on the storage media, whereby, in the event of an electromagnetic event, information at the time of the event can be preserved on the storage media.

Abstract: Camera arrangements that can include electromagnetic protection, such as from EMP/IEMI events, is disclosed. One example camera arrangement includes a camera including a viewfinder having a lens, and an electromagnetically shielded enclosure defining an interior volume containing the camera and configured to include at least one opening aligned with the lens. The camera arrangement includes an electromagnetically dampening barrier disposed across the at least one opening, the barrier configured to shield the interior volume of the enclosure from electromagnetic signals while exposing an optical path between the lens and objects external to the enclosure.

Abstract: Equipment and systems for protecting electronics against damage or upsets from electromagnetic pulse (HEMP or EMP), intentional electromagnetic interference (IEMI), and high power RF weapons are disclosed. This equipment can include a shielding arrangement includes a metallic enclosure having an interior volume defining a protected portion and an unprotected portion separated by an electromagnetically shielding barrier, and having a portal providing access to the protective portion and including an access opening, a shielding cover sized to cover the access opening, and an electromagnetically sealing gasket positioned around a perimeter of the access opening. The shielding arrangement also includes one or more filters positioned at least partially within the unprotected portion and along the electromagnetically shielding barrier to dampen electromagnetic signals and/or power signals outside a predetermined acceptable range.

Abstract: Systems and method for detecting potentially harmful harmonic and direct current signals at a transformer are disclosed. One such system includes a plurality of detection components electrically connected to electrical signal lines leading from one or more connection points on a power grid, and a plurality of threshold detectors, each threshold detector configured to compare an incoming signal from a detection component to a predetermined signal having a threshold. The system also includes a controller receiving an output from each of the plurality of threshold detectors and configured to drive at least one external component in response to receiving an indication from at least one of the plurality of threshold detectors of a detected signal above a threshold.

Abstract: A continuous grounding system for use in an alternating current system including a transformer is disclosed. The system includes a switch assembly connected between a transformer neutral of a transformer and a ground, the switch assembly having an open position and a closed position, the open position disrupting the path through the switch assembly between the electrical connection and the transformer neutral, and the closed position establishing a path connecting the electrical connection to the transformer neutral through the switch assembly, wherein in normal operation of the alternating current electrical device the switch assembly remains in a closed position. The system also includes a DC blocking component positioned in parallel with the switch assembly and connected between the transformer neutral and the ground.

Abstract: Detectors and other apparatus for determining the presence of electromagnetic events are disclosed. One such system includes an electromagnetically shielded enclosure and a detector configured to detect an electromagnetic field event occurring in the proximity of the enclosure. The detector includes an antenna and a circuit electrically connected to the antenna. The circuit includes electronics communicatively connected to the antenna via a direct current isolation circuit, and an equalizer compensating for the differentiating frequency response of the antenna. The circuit also includes a logarithmic amplifier electrically connected to the equalizer and configured to generate a range of signals based on signals received at the antenna, and a peak detector receiving signals from the logarithmic amplifier and configured to capture a peak value of the signals. An electromagnetic field event is detected at least in part based on the peak signal value.

Abstract: A method and apparatus configured to detect electromagnetic field events are disclosed. One apparatus includes an antenna and a circuit electrically connected to the antenna. The circuit includes electronics communicatively connected to the antenna via a direct current isolation circuit and an equalizer compensating for the differentiating frequency response of the antenna. The circuit also includes a logarithmic amplifier electrically connected to the equalizer and configured to generate a range of signals based on signals received at the antenna. The circuit further includes a peak detector receiving signals from the equalizer and configured to capture a peak value of the signals. The electromagnetic field event is detected at least in part based on the peak signal value.

Abstract: An electromagnetically shielded enclosure is disclosed. One such system includes a continuously welded shell having a top, a bottom, and a plurality of side walls cooperating to enclose an interior volume, the interior volume sized to receive electronic equipment and allow human entry. The enclosure is constructed from electromagnetically conductive materials and includes continuous welds along seams joining each material. The enclosure includes a sally port located within the enclosure. The sally port includes a first door in one of the plurality of side walls and constructed from electromagnetically conductive materials. The sally port also includes a second door constructed from electromagnetically conductive materials. The sally port defines a secondary interior volume within the enclosure sized to allow human entry through either the first or second door.

Abstract: Method and means are disclosed for rapidly tuning a laser over a large number of wavelengths. The means of the present invention includes first and second reflecting means which define the optical resonating cavity of a laser, and further includes a dispersive means adapted to sequentially select and direct one and only one of the wavelengths of light from the beam emitted by a laser's amplifying medium along a path back through the laser's amplifying medium as one of the reflecting means is continuously rotated. One embodiment of the present invention forms the rotating reflecting means as a faceted polygonal solid with at least one face thereof being a Littrow reflective grating. A pulsed laser is adapted to tune to a different wavelength of light each time some or all of the grating faces of the polygonal solid are rotated to intercept the longitudinal axis of the laser.

Abstract: A single optical sensor coupled to an oil return line in an internal combustion engine is coupled to a control circuit for determining during a first time interval when the engine is started whether the crankcase oil level is sufficient and during a second time interval after the engine is running whether the oil needs to be changed.

Abstract: Magnetic and dielectric properties of a sample are determined by measuring the microwave absorption of the sample. A cavity containing the sample material is coupled to a microwave source and the radiation propagated to the cavity is modulated at a reference frequency. A microphone coupled to the cavity senses the pressure fluctuations resulting from the thermal changes generated in the sample by the absorption of the modulated microwaves and the microphone signal is analyzed at the reference frequency to provide an electrical output which is a measure of the microwave absorption by the sample material. Both dielectric and magnetic properties of the sample can be measured.

Abstract: Spherical parts such as ball bearings are inspected by rolling the parts down sizing rails so that they rotate rapidly with minimal translational motion at a point where they drop through the sizing rails. In a region of rapid rotation the part is inspected by an array of optical systems covering the entire area of the part. Each system focuses a small line of light on the part and in a direction slightly misaligned with the center of the part and the same optics focuses specularly reflected light from the part to a detection region where the light level is measured and a corresponding electrical signal is produced. When the line image scans over a defect, the resulting absorption or scattering of the light causes a rapid decrease in the light received at the measuring location so that a detectable change in the electrical signal occurs.

Abstract: The orientation of an industrial part such as a microcircuit chip having a pattern of dominant parallel lines is determined by an optical method. An image of the parallel line pattern is smeared or defocused in a known direction such that the resultant smeared image of the part reveals the lines in sharp detail when they are parallel to the known direction of smearing and are blurred if the lines are angularly displaced from the known direction. By rotating the image of the pattern relative to the smear direction and determining the angle at which maximum sharpness occurs, the angular orientation is determined. By correlating the pattern of sharp lines of the smeared image with a similar reference pattern of known position, the positional orientation of the part is also determined. When two angularly displaced families of parallel lines are present on the object, positional coordinates relative to two axes are determined.