Abstract: There is provided an aircraft which can minimize its radar signature emission. Such aircraft comprises a fuselage having a lower fuselage portion. An internal fuselage cavity is defined within the lower fuselage portion and contains all landing gears and bombs therein. Moreover, a cavity-enclosing door is engaged to the lower fuselage portion. This specific cavity-enclosing door may form a closed position relative to the internal fuselage cavity to enclose all of the landing gears and bombs therein. In this respect, enclosure of all of the landing gears and bombs solely through the cavity-enclosing door may minimize the radar signature emission from the fuselage.

Abstract: A high-velocity, accurately responsive impingement heater provides heated air at a substantially constant temperature to a process location to effect control of a process. The heater includes an air line for conducting air from an inlet thereof to the process location. A heat exchanger, including a plurality of electrical heating elements, heats air conducted through the air line. A power driver is connected to the heat exchanger and applies current to the heat exchanger. A controller is connected to the driver and receives a predetermined process temperature input from the user, as required for effecting control of the process. A process temperature sensor is positioned at the process location and measures the temperature of the air provided to the process location. The process temperature sensor provides a process temperature signal to the controller which is indicative of the air temperature at the process location.

Abstract: An apparatus and associated method is disclosed for increasing the maximum input frequency of a frequency divider system by altering the division ratio in the frequency divider system. In an exemplary form, the apparatus includes an electrical mixer circuit to combine an internal and an external frequency input signals into a combination frequency signal and a frequency divider circuit to receive the combination frequency signal and to frequency divide the combination frequency signal by a predetermined number, a signal splitter and a directional coupler in operative to receive the divided frequency signal and to generate an output frequency signal and a feedback frequency signal wherein the feedback frequency signal is identical in frequency to the output frequency signal and becomes the internally inputted frequency signal for the mixer. In this way the maximum input frequency of the frequency divider system can be advantageously increased.

Abstract: A process for oxidizing iron ions contained within iron-doped lithium niobate. The process comprises the steps of protonating the iron-doped lithium niobate crystal and then placing the same into a pressure chamber where between 10-100 atmospheres of dry, ultra-pure pressurized oxygen are applied. While under pressure, the crystal is heated to approximately 950° C. at a rate not to exceed 50° C. per minute, and preferably at a rate not less than 25° C. per minute. The resulting lithium niobate crystal will thereafter contain iron ions wherein the divalent iron ion ratio to the trivalent iron ion ratio is approximately 1:100.

Abstract: A fluorescent ballast control process for a fixed and variable frame rate method of driving a fluorescent ballast to control the brightness of a fluorescent lamp load over a brightness range. The fixed frame rate process uses a fixed number of pulses in each frame. The variable frame rate process uses a variable number of pulses in each frame. When the two processes are combined, the control is gradual in response to a user control signal (BRIGHT). The transition from the fixed to the variable frame rate control process occurs seamlessly as the variable BRIGHT×BRIGHT×OVER where BRIGHT×OVER is calculated.

Abstract: A power supply Active Bleed Voltage Balancing Circuit for attachment to the outputs of a regulated power supply having at least a first output and a second output to shunt load power from an output that has become unloaded and has an output voltage that is rising past an acceptable limit. The Active Bleed Voltage Balancing Circuit has an inductor with a first terminal coupled to the first power supply output. The second output voltage exceeds the first output voltage. An oscillator driven totem-pole driver alternately drives the inductors second terminal to the power supply second output and then to ground. The duty cycle ratio is adjusted to equalize the volt-seconds applied in each position. An alternative circuit uses a multiple winding inductor with a 50/50 duty cycle and with balancing achieved by adjusting the turns ratio to equal the ratio of the output voltages.

Abstract: Plasma spraying of particulate thermotropic liquid crystalline polymers onto the surfaces of composite and metallic structures. The present plasma spray process employs a conventional direct current electric arc plasma spray gun in which an inert plasma gas is introduced, caused to swirl, and discharges as a rotating plasma flame having an exceptionally high temperature, above about 14000.degree. K, into which the particulate liquid crystal polymer is discharged for melting and propulsion onto the target surface. The target surface preferably is preheated, and the molten particles deposit and cool to form a build up of the desired thickness. Cooling is regulated by post-heating the deposit to a temperature between about 200.degree. F. and 500.degree. F.

Abstract: A double-balanced monolithic microwave integrated circuit mixer is fabricated on a GaHs substrate with a radio frequency microstrip balun formed thereon and a local oscillator microstrip balun formed thereon. A crossover diode ring is also formed upon the substrate. The radio frequency microstrip balun and the local oscillator microstrip balun provide enhanced electrical isolation between a radio frequency port and a local oscillator port, enhanced spurious response suppression, and enhanced local oscillator noise rejection in only 0.021".times.0.048" of circuit area.

Abstract: An internal combustion engine of either two-cycle or four-cycle construction including a block having at least one cylinder bore therein having sidewalls carrying a liner of a structural fiber reinforced ceramic matrix composite material disposed in sealed fiber reinforced sliding relationship within the cylinder bore, and a cylinder head sealing atop end of the cylinder bore to form a closed combustion chamber in combination with the piston. The cylinder head also has the structural fiber reinforced ceramic matrix composite material disposed on an inner surface thereof facing the combustion chamber. The preferred engine is a two-cycle engine having an externally scavenged intake system and an oil sump lubricating system thereby eliminating the need to separately mix or inject lubricating oil. Higher operating temperatures and closer tolerances allow higher fuel efficiency and less pollutant production.

Abstract: The output matching networks normally included in a microwave power transistor package as well as the transistor combining network therefor are eliminated for heating applications, e.g. microwave ovens. In a preferred embodiment, the transistor dies of four microwave silicon bipolar power transistors are directly connected to the low impedance points of a common patch type antenna element, also referred to as an applicator, located within the wall of a heating chamber in place of a magnetron. Each pair of power transistors are electrically spaced one half wavelength apart and are located transverse to each other on the antenna. The transistors are operated in pairs with a 180.degree. phase difference so that mutually orthogonal longitudinal modes are excited in the antenna. Moreover, the transistors are frequency modulated over their prescribed frequency band to eliminate standing waves in the load, i.e. the article or substance being heated or cooked.

Abstract: A power supply for providing a symmetric drive for an AC electroluminescent (EL) display panel includes a single power supply which provides two voltage signal values of opposite polarity V.sub.pos,V.sub.neg to the panel's row drivers. The supply also corrects the difference between the two voltage signal values V.sub.pos,V.sub.neg as a function of the difference between the maximum column driver voltage value V.sub.col and its nominal value to reduce latent images on the display panel. By utilizing a single switching regulator to generate the opposite polarity row voltages V.sub.pos,V.sub.neg the circuit complexity and cost associated with providing a symmetric drive for an EL panel is reduced.

Abstract: An integrated circuit for use in a phased array antenna system having a central processing unit. The integrated circuit is associated with one of a plurality of antenna elements of the phased array antenna system. The integrated circuit includes an ID memory for storing a unique ID addressable by the central processing unit, and receives global commands from the central processing unit globally transmitted over a distributed serial bus. Upon detecting a global command, the integrated circuit compares an ID address associated with the global commands with the ID stored in the ID memory. The integrated circuit recognizes global commands as local commands to be executed locally when the ID address associated with the global commands is the same as the ID stored in the ID memory. In response to the local commands, the integrated circuit generates and provides control signals to the associated one of the antenna elements of the phased array antenna system.

Abstract: A rotating antenna system subject to both tilt and translation forces includes first and second tilt sensors each having a pendulum assembly of a different length than the other sensor. The sensors provide identical output signals in response to a tilt, but different output signals in response to a translation of the antenna. Circuitry is provided for eliminating the effects of translation so as to obtain a tilt angle correction signal for correcting the radar height calculation.

Abstract: A non-reflecting, wave-absorbing structure absorbs sound, radio and radiation wave. The non-reflecting, wave-absorbing structure combines an outer non-reflecting wave structure and a wave-absorbing portion. The outer non-reflecting wave structure allows for the transmission of the wave therethrough without appreciable reflection and the wave-absorbing material absorbs substantially all of the transmitted wave. In the case the wave to be absorbed in a sound wave, the wave-absorbing material is preferably an epoxy in a chemical state of gelatinization which is prevented from reaching a state of cure.

Abstract: A low frequency sonar system for detecting buried cables and pipelines that includes at least three sub-bottom sonar beam projectors arranged athwarships, i.e. transverse to the central longitudinal axis of the system platform and a common receiver, the latter preferably being an arc focused device. The projectors are comprised of parametric transmitters, with the two outer projectors canted relative to the middle projector so that sonar return signals having a relatively narrow beamwidth are directed to the bottom and returned as a sequence of specular reflections along the length of sub-bottom targets to the common receiver. The transmission from the three parametric transmitters result in three spaced apart "hits" on the target which are displayed as a function of depth. Three detections in a row, i.e. at the same depth, provide an indication of a cable or pipeline buried beneath the bottom of a body of water.