Abstract: A fluorescent lighting system that includes a gas containment vessel having an internal phosphor coating and containing an ionizable gas, field concentrator electrodes supported inside or outside the gas containment vessel, and an RF power source coupled directly or capacitively to the field concentrator electrodes.

Abstract: An inhomogeneous broadband absorber of electromagnetic energy constructed from an aerogel-lossy dielectric composite, where the concentration of the lossy dielectric increase across its thickness such that the composite's dielectric properties vary from those of the aerogel to those of the lossy dielectric. Materials useful for serving as the lossy dielectric include polar molecules, polar icosahedral molecules, polyaniline electron-conducting polymers, and polyprrole electron-conducting polymers. Another inhomogeneous layer absorber is constructed from an aerogel that is intrinsically a lossy dielectric. The variation in dielectric properties is achieved by increasing the density of the aerogel across the thickness of the material. Aerogel materials for such an absorber include organic aerogels which have been pyrolized in an inert atmosphere to give vitreous carbon aerogels. Methods for fabricating these absorbers are described.

Abstract: A parallel plate transmission line (20) is formed by conformal application of one or more dielectric and conductive layers to the surface under test (70). A signal generator (42) is employed to transmit variable frequency signals (60) along the transmission line (20). Discontinuities in the transmission line (20) cause reflections (62) which are received by a receiver (48). A processor (44) coupled to the signal generator (42) and receiver (48) detects and locates the discontinuities.

Abstract: A combined scene-based and DC-restored image restoration system enhances the utility of video images generated from the input of a forward-looking infrared system. This system and related methods remove a desired portion of the DC content from each of a plurality of input signals that are generated from a plurality of adjacent portions of a source image to obtain a plurality of resultant signals from which a plurality of video images is produced.

Abstract: A dielectric material is formed into a structure having two parallel broad surfaces with one or more raised integral portions extending transversely across at least one of the broad surfaces. The exterior is uniformly conductively coated resulting in a parallel plate waveguide having a continuous transverse stub element disposed adjacent one plate thereof. Purely reactive elements are formed by leaving the conductive coating on the terminus of the stub element, or by narrowing the terminus of the stub element. Radiating elements are formed when stub elements of moderate height are opened to free space. Radiating, coupling and/or reactive continuous transverse stub elements may be combined in a common paralled plate structure in order to from a variety of microwave, millimeter wave and quasi-optical components including integrated filters, couplers and antenna arrays.

Abstract: A torque oscillation compensation system and circuit that uses torque transducer feedback derived from an output shaft of an electric vehicle motor to compensate for electrical motor pulsations such as are experienced in an electric vehicle. A torque input source provides a torque input signal, that is coupled to a summing circuit. A controller is coupled to the summing circuit, and power switching circuitry is coupled between the controller and the electric motor. A torque transducer is coupled to the output shaft of the motor to sense torque pulsations. An oscillation compensation circuit is coupled between the torque transducer and the summing circuit that generates a feedback compensation signal that is combined with the torque input signal to compensate for output shaft oscillators.

Abstract: 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.

Abstract: An array of dielectric vias formed in the insulating layers of a unitized multilayer circuit structure wherein the dielectric vias have a dielectric constant different from the dielectric constant of the insulating layers in which they are formed.

Abstract: 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.

Abstract: A phase detector circuit which includes a first fixed delay circuit responsive to the first input signal for producing a fixedly delayed first signal which is a replica of a first input signal and delayed relative thereto by a fixed delay, a second fixed delay circuit responsive to a second input signal for producing a fixedly delayed second signal which is a replica of the second input signal and delayed relative thereto by the fixed delay, a controlled delay circuit responsive to the second input signal for producing a controllably delayed second signal and delayed relative thereto by a controlled delay, a first phase detector responsive to the fixedly delayed first signal and the adjustably delayed second signal for providing a first phase detector output that comprises the output of the phase detector circuit, a second phase detector circuit responsive to the fixedly delayed second signal and the adjustably delayed second signal for providing a second phase detector output, and an integrator responsive to

Abstract: A torque oscillation compensation system and circuit that senses battery current to compensate for electrical motor torque pulsations. An input source provides a torque/current command input signal that drives the motor, and a summing device has one input coupled to receive the torque/current command input signal. A controller is coupled to the summing device and to power switching circuitry that is coupled between the battery and the electric motor. An oscillation compensation circuit is coupled between the battery and the summing device that generates a compensation signal that is combined with the torque/current command input signal and compensates for output shaft oscillators. The oscillation compensation circuit comprises an AC coupling capacitor, an amplifier having a predetermined transfer function that is designed to provide for the proper amount of compensation. The present invention compensates for the torque fluctuations caused by induction motors and permits stable operation thereof.

Abstract: A step attenuator using a PIN diode for use with microwave circuits. The step attenuator circuit provides for stepwise controlling the current applied to the microwave monolithic integrated circuit. The step attenuator circuit comprises a driver circuit and a attenuator circuit coupled thereto. The driver circuit that comprises a temperature sensor, a comparator circuit coupled to the temperature sensor for comparing the temperature value sensed by the temperature sensor to predetermined reference voltages and for providing a plurality of output signals that are indicative of a respective plurality of temperature values sensed by the temperature sensor, and a resistor network coupled to the comparator circuit that is adapted to set the respective values or current provided by the driver circuit.

Abstract: A dielectric material is formed into a structure having two parallel broad surfaces with one or more raised integral portions extending transversely across at least one of the broad surfaces. The exterior is uniformly conductively coated resulting in a parallel plate waveguide having a continuous transverse stub element disposed adjacent one plate thereof. Purely reactive elements are formed by leaving the conductive coating on the terminus of the stub element, or by narrowing the terminus of the stub element. Radiating elements are formed when stub elements of moderate height are opened to free space. Radiating, coupling and/or reactive continuous transverse stub elements may be combined in a common parallel plate structure in order to form a variety of microwave, millimeter wave and quasi-optical components including integrated filters, couplers and antenna arrays.

Abstract: A torque oscillation compensation system and circuit that uses motor speed to compensate for electrical motor torque pulsations. An input source provides a torque/current command input signal that drives the motor by way of a controller, and a summing device has one input coupled to receive the torque/current command input signal. A controller is coupled to power switching circuitry that is coupled between the power source and the electric motor. A speed sensor is coupled to the motor and is adapted to provide a motor speed output signal. An oscillation compensation circuit is coupled between a speed sensor and the summing device that generates a compensation signal in response to the motor speed output signal that is combined with the torque input signal and compensates for output shaft oscillations.

Abstract: A dual junction back-to-back four-port microstrip circulator made up of two three-port single junction circulators whose substrates lay back-to-back and are interconnected with a coaxial feedthrough. When used in an active antenna array application, the transmit and receive ports will be located on different levels of the device. The back-to-back configuration allows sharing either a single magnet for biasing or a single magnetic shield carrier for bias return, with a magnet on top of each substrate. The circulator has the advantages of small size and operation over a wide frequency band.

Abstract: A holographic center high mounted stop light (CHMSL) employing a linear lamp source comprising a long and narrow cylindrical gas discharge bulb, a non-imaging light concentrator cavity, a plastic light guide and a hologram. The CHMSL is characterized by previously unattainable compactness, weight savings, rear occupant headroom, driver rearward visibility, and electrical efficiency.

Abstract: A method of tracking an object in the Doppler dimension that provides for improved imaging. The method tracks the centroid of the object's Doppler and smooths out noisy estimates of its phase history. The tracking and smoothing combine to improve tracking performance and image quality. Doppler signals are generated by a coarse Doppler tracker that removes translational motion of the object. Pulse pair processing produces an estimate the Doppler centroid of the object. For each pair of adjacent pulses, pulse pair processing is applied to individual range bins, and the outputs are combined to estimate the Doppler centroid of the object at that particular time. A low pass filter is used after pulse pair processing to smooth out phase increments. Phase increment smoothing then filters the output signals from the filter with a smooth curve, such as a second-degree polynomial. Phase recursion then produces a phase history. The recursive phase history is differenced with updated, appropriately delayed phases.

Abstract: A waveguide holographic telltale display for displaying images to a vehicle driver via the vehicle windshield. A light source injects light into the base of a clear inner windshield singlet. A mirror hologram between the inner and outer singlets confines a majority of the injected light to the inner singlet. An image hologram between the windshield singlets diffracts light out to the vehicle driver. A halfwave plate between the image hologram and the inner singlet reduces ghosting and allows the driver to view the images even through polarized sunglasses. IR light is blocked by a tinted outer singlet or a holographic solar coating. The display does not suffer from ambient turn from the sun, and the light source is hidden away from the vehicle dash.

Abstract: A zero-degree mirror reflection hologram is embedded into a vehicle windshield to reduce veiling glare. The hologram partially reflects sunlight in the visible wavelength range incident on the windshield between 0 and substantially 70 degrees, and therefore blocks a substantial portion of visible sunlight that would otherwise pass through the windshield and reflect off the dashboard. The portion of light that does reflect off the dashboard which could enter the driver's eyebox does not reflect appreciably off the hologram because the hologram reflection peak is in the ultraviolet at high off-axis angles.

Abstract: A scan flip-flop cell including a flip-flop, a feed-back path by which the output of the flip-flop can be controllably held, and a latch in the feedback path that allows the cell to store two bits of data simultaneously.