Abstract: A magnetic storage system includes a magnetic storage medium comprising a keeper layer of relatively low permeability soft magnetic material deposited upon a magnetic storage layer or between multiple magnetic storage layers. The low permeability keeper layer may be disposed either above or below the magnetic storage layer. In the unsaturated state, the keeper layer acts as a shunt path for flux emanating from recorded transitions on the magnetic storage layer, producing an image field of the recorded transitions in the keeper. This shunt path prevents signal flux emanating from the recorded transitions from reaching the head. To read data from a recorded transition on the magnetic storage layer; a bias current is applied to windings of the head, creating a bias flux which saturates a portion of the keeper layer. Once saturated, this portion of the keeper can no longer shunt flux emanating from the recorded transition, which is the region represented by the head reproduce transducer.

Abstract: A deflection mirror tower (DMT) of a multiple-disk array, optical storage system includes a plurality of prism members, each having an angular mirror surface, arranged along a vertical axis of the DMT and configured at a predetermined angular orientation to deflect a laser beam to a respective disk surface. The DMT is generally fabricated using a two-level partitioning process. Several prepared glass substrates, i.e., one for each mirror type, are initially sliced into bars having predetermined geometries. A bar from each substrate is sequentially aligned to a master reference and bonded to adjacent bars to form an intermediate bar stack. The stack is then segmented into a plurality of DMT components, each having a plurality of prism members.

Abstract: An automatic scan tracking, helical tape type of data recorder is disclosed herein along with its method of operation. Data is written onto magnetic recording tape along with data retrieval information by means of a rotating scanner assembly forming part of the recorder as the recording tape moves at a given recording speed in cooperative engagement with the scanner assembly. Data is normally retrieved from the recording tape along with the data retrieval information by means of the rotating scanner assembly as the recording tape moves longitudinally at the same given recording speed. In operation, the rotating scanner assembly of the recorder retrieves data and data retrieval information from a segment of the recording tape while the latter is not moving, that is, during a period when the tape is stationary for enabling adjustment of the read head position relative to the track depending on the evaluation of the data resulting from the stationary tape read.

Abstract: An electroluminescent display includes a transparent electrode (4) and a metal assist structure (6) formed over a portion of the transparent electrode (6) such that the metal assist structure (6) is in electrical contact with the transparent electrode (4). The metal assist structure (6) includes a first refractory metal layer (10), a primary conductor layer (12) formed on the first refractory metal layer (10), and a second refractory metal layer (14) formed on the primary conductor layer (12). The first and second refractory metal layers (10, 14) are capable of protecting the primary conductor layer (12) from oxidation when the electroluminescent display is annealed to activate a phosphor layer (18). In an alternate embodiment, an electroluminescent display includes a substrate (2) and a metal electrode (22) formed on the substrate (2).

Abstract: A fast switching, variably polarized lens is placed in front of a radar antenna which radiates an electromagnetic wave having any fixed polarization. The radiated electromagnetic wave is coupled to the lens and the switching elements within the lens transform the polarization of the radiated electromagnetic wave as commanded. Each transmit pulse may take on any polarization which the lens is capable of providing independent of the polarization of the previous transmit pulse. Similarly, during receive mode the lens can be set up to allow the radar system to receive a return signal of any polarization independent of the polarization of the return signal's associated transmit signal.

Abstract: An airport vehicle identification system includes a ground surveillance radar system which radiates both a conventional radar signal and a beacon interrogation signal. The radar receives i) a backscatter signal from the skin returns of a target and ii) an encoded ID signal indicative of the target identity. The encoded ID signal is transmitted by a vehicle (e.g., an aircraft) mounted transponder in response to receiving the beacon interrogation signal. The transponder can be located within an external vehicle light housing such as an aircraft collision avoidance light. This invention fills the critical void in airport traffic control of providing ground controllers with electronic airport surface surveillance data which includes both vehicle position and identity.

Abstract: A phased array antenna includes an array of phase shifters, each shifter being operable for shifting the phase of RF energy passing therethrough. Each shifter includes a quantity of ferroelectric material disposed throughout a region. RF energy propagating from a source passes through the material. A thin conductive electrode is disposed in the center of the material, the electrode having a bias voltage imposed thereon. Such voltage creates an electric field across the material, which for a uniaxial ferroelectric orients the optic axis of the material in a direction which is both normal to the direction of propagation of the RF energy and parallel to the polarization direction of the RF energy. The electric field changes the wave propagation constant (i.e., for a uniaxial ferroelectric, the extraordinary wave refractive index, n.sub.e), producing a varying path length of the RF energy in the material, resulting in a controllable alteration of the phase of the RF energy.

Abstract: A transient free synchronizer stores an input trim signal value on command, and provides an output signal value which transitions in a smooth, continuous manner, when the synchronizer is commanded to the store the input signal. Synchronizers are typically used to capture desired aircraft attitude, position, or velocity trim points for use in aircraft autopilot and automatic flight control systems.

Abstract: A modulator with improved damping comprises a charging network which limits the rate at which energy is transferred into a pulse forming network, and a switch to discharge the energy stored in the pulse forming network when the network has charged to a predetermined energy level. The pulse forming network discharges into the primary winding of a transformer which couples the energy to its secondary winding which routes the energy to an RF power generating tube. The modulator also includes an improved damping network which places a diode and resistor electrically in parallel with each other, and both in series with the switch to reduce the magnitude of the post-pulse voltage oscillations.

Abstract: A lubricant applicator system for electronic connector pins is designed to uniformly apply a lubricant to the pins to reduce the force necessary to install and extract a circuit board in the motherboard. The system includes a reservoir tank which supplies lubricant to a container into which electronic pins of an assembled connector are immersed, with holes disposed on the bottom surface of the container such that the lubricant enters the container via the holes and rises within the container to a certain height which is controlled by an elbow valve, thereby coating only a predetermined length of the electronic pins with lubricant.

Abstract: A helicopter flight control system (21) includes a model following control system architecture which automatically provides a coordinating yaw command signal to the helicopter tail rotor to coordinate helicopter flight during a banked turn. The control system processes information from a variety of helicopter sensors (31) in order to provide the coordinating yaw command signal on an output line (72) to the tail rotor (20) of the helicopter.

Abstract: A helicopter flight control system includes an automatic turn coordination system which provides a coordinating yaw command signal to the tail rotor of the helicopter. The system stores on command a trim attitude (e.g., signals indicative of bank angle, lateral ground speed, and lateral acceleration) about which automatic turn coordination is provided, thus providing the pilot with automatic turn coordination about attitudes other than wings level.

Abstract: A helicopter flight control system (21) includes a model following control system architecture which automatically provides a coordinating yaw command signal to the helicopter tail rotor to coordinate helicopter flight during a low speed banked turn. The control system processes information from a variety of helicopter sensors (31) in order to provide the coordinating yaw command signal on an output line (72) to the tail rotor (20) of the helicopter.

Abstract: A helicopter fly-by-wire flight control system (21) includes a model following control system architecture which provides the pilot with maneuvering feel. Maneuvering feel is generated by varying the gain of a rate model (52) in the control system to schedule a constant sidearm controller force per g of load factor currently on the helicopter main rotor. This gain variation works in conjunction with control logic which requires the pilot to apply a nose up pitch command during steep banked turns in order to offset a control system induced downward (pitch) bias of the aircraft nose. The control system induced bias is generated only during steep banked turns, thus allowing the pilot to fly shallow banked coordinated turns without having to apply a nose up pitch command.

Abstract: A helicopter flight control system (21) includes a model following control system architecture which operates in a velocity command mode at low ground speeds. The control system processes information from a variety of helicopter sensors (31) in order to provide a command signal to the main rotor (11) of the helicopter which results in a ground speed which is proportional to the input provided via a sidearm controller (29).

Abstract: An improved radar system utilizing the principle of nonlinear contact effects for detecting and identifying a target, includes two radar transmitters (12,16) at least one of which is a baseband pulse radar transmitter. Both transmitters illuminate the same target and the signals from each transmitter are mixed in a nonlinear junction (40) of the target. Mixing the two signals provides a target return signal whose frequency spectrum contains cross product frequency components having high resolution target data due to the broad spectral content of the baseband pulse, and thus provides a system capable of detecting and identifying the illuminated target.

Abstract: The rate of change of cabin air pressure in an aircraft cabin during aircraft ascent and descent is controlled as a function of a ratio which is equal to (P.sub.ld -P.sub.c)/(P.sub.ld -P.sub.a) during descent, and is equal to (P.sub.cc -P.sub.c)/(P.sub.cr -P.sub.a) during ascent, where P.sub.ld is ambient pressure at the aircraft landing site, P.sub.c is cabin pressure, P.sub.a is external aircraft ambient pressure, P.sub.cc is cabin pressure at cruise altitude, and P.sub.cr is ambient pressure at cruise altitude. A set point value for the ratio is computed throughout aircraft ascent and descent, and compared to the ratio to schedule a variable flow area of an outflow valve in order to drive the difference (i.e., the error) between the ratio and the desired value for the ratio to zero.

Abstract: An improved electrical connector assembly with EMI protection includes: (i) a conventional receptacle connector containing a plurality of electrically conductive pins surrounded by a receptacle flange, (ii) a conventional plug connector having a plurality of electrically conductive sockets surrounded by a plug flange, and (iii) an elastomeric belly band having conductive particles disposed throughout the band. The band is placed over the receptacle flange in tightly spaced relationship thereto, and the receptacle connector is mated with the plug connector to construct the assembly, such that the belly band covers both the plug and receptacle flanges to create a high conductivity path for impinging EMI. The EMI is attenuated within the band substantially reducing the detrimental effect of the EMI on the electrical signals conducted along the conductive pins/sockets.

Abstract: A helicopter flight control system includes a model following control system architecture to control helicopter response about the yaw axis. The control system processes information from a variety of helicopter sensors in order to provide an output command signal to the tail rotor. Yaw control is accomplished by applying a force on a sidearm controller which provides a yaw axis command signal that is used to schedule a desired yaw rate of change. The lateral acceleration and airspeed signals are used to compute a synthesized yaw rate signal which is compared against the desired yaw rate of change, thus allowing the pilot to control lateral acceleration when he applies force on the sidearm controller.

Abstract: A helicopter flight control system includes a model following control system architecture having provisions to compensate for Euler singularities which occur when the pitch attitude of the helicopter starts to approach ninety degrees. The control system processes information from a variety of helicopter sensors in order to provide the control commands to the helicopter main and tail rotors. The present invention synchronizes a sensed attitude signal, and a desired attitude signal as the pitch attitude of the helicopter approaches ninety degrees to compensate for the Euler singularities.