Abstract: A non-reciprocal latching phase-shifter uses a slab of a high-dielectric constant material embedded in ferrite to substantially concentrate the electromagnetic energy within the dielectric slab, thus eliminating the need for a conductive waveguide, and to provide for a small amount of energy leakage into the adjacent ferrite whose state of magnetization can be varied, thus providing for a variable phase-shift. In one embodiment, parallel high-K dielectric strips are sandwiched between grooved ferrite sheets to provide a low-cost phase-shifter array.

Abstract: A crossed-field amplifier tube with a cathode slow wave structure at a high electrical potential is coupled to a high frequency of source and a load by a direct current isolated radio frequency transition. The transition is contained within the vacuum of the tube to prevent electrical breakdown between the transition and ground.

Abstract: A radiographic camera is provided having a scintillator and a plurality of photodetectors positioned to face the scintillator for providing position electrical signals. The photodetectors are disposed at different, progressively increasing, predetermined distances from a reference point to a distal point adjacent the outer periphery of a nominal field of view of the camera. The position electrical signal provided by each one of the plurality of photodetectors has an amplitude related to the distance between such one of the photodetectors and the point of impingement of radiation on the scintillator. Circuitry, responsive to a plurality of the position electrical signals, is provided for producing an extrapolated correction electrical signal, such correction electrical signal having an amplitude representative of the distance between the point of an impingement of radiation on the scintillator and a point beyond the distal point and outside of the nominal field of view of the camera.

Abstract: An ultrasonic transducer and its method of fabrication wherein bonding between an impedance matching layer on one side of a piezoelectric layer and a support layer on the other side of the piezoelectric material is made by providing onto each material a smooth, thin gold film on the smooth surfaces of the layers which are to be in contact with one another in the assembled transducer. The layers are bonded to each other by the gold films under moderate temperature and pressure to form the transducer. Sawing of the impedance matching and piezoelectric layers into a plurality of parallel transducers attached to the support layer forms an array.

Abstract: A two level turntable adapted for use in a microwave oven. The top level platform which may include a roasting rack is removably supported above the bottom level by a plurality of columns. The bottom level platform has a shaft that extends downwardly through an aperture in a microwave shielding enclosure to a motor. The motor components consisting of a coil spring and a braking mechanism are mounted in substantially the same horizontal plane to provide a relatively low vertical profile. Although the low profile is important when the bottom level platform is used by itself, it is even more important when the top level platform is mounted on top. The shielding enclosure which includes a pan shaped bottom has a downwardly bent lip from the lid to provide a low microwave field region adjacent to the connection of the pan and lid.

Abstract: A laser system having an optically unstable cavity with a unique optical center axis longitudinally offset from the center axis of the cavity toward one side of the resonator to obtain an unobscured output beam from the opposite side. The resonator also has astigmatic magnification which provides for a greater volume utilization of the gain medium than otherwise possible. In a preferred embodiment, the off-axis astigmatic resonator employs spherical mirrors at off-normal incidence to provide for different magnification in two orthogonal planes.

Abstract: A combination microwave and convection oven in which a gas burner positioned outside the oven provides heated combustion products which are drawn from the burner area along with vapor from an outlet of the oven by a blower system and the combined output of the blower system is blown into the oven through an oven inlet region in the oven wall. Both the oven outlets and the oven inlet are formed of holes substantially less than one-half wavelength in diameter. A predetermined portion of the blower output system is blown through an exhaust vent thereby creating slight negative pressures in the oven and in the burner plenum to accurately control the air flow through the burner.

Abstract: A microwave oven having a directional rotating antenna axially supported on an axis of one wall of a microwave oven cavity of the microwave oven which provides circularly symmetric uniform energy distribution of microwave energy within the microwave oven cavity and consistent heating of a product in the microwave oven cavity. The directional rotating antenna includes a two-by-two array of antenna elements where each element is an end driven half-wavelength resonating antenna element supported by a length of conductor perpendicular to the wall of the microwave oven cavity. A parallel plate transmission line connects to each of the supports, four of which join at a junction which connects to a cylindrical probe antenna. The probe antenna is excited by microwave frequency currents of a waveguide adjacent to the wall of the microwave oven cavity. The directional antenna is rotated by a moving stream of air circulated through the microwave oven cavity.

Abstract: A combination microwave gas convection oven having a tubular burner operating in an induced draft environment. A blower system draws air from a combustion chamber forcing it into the heating cavity. The slight pressure created in the combustion chamber draws in air from the heating cavity through perforations communicating therebetween completing the convection recirculation. The negative pressure in the combustion chamber also causes secondary combustion air to be drawn up along the sides of the burner which is positioned adjacent to an aperture in the floor of the combustion chamber. A plurality of top ports in the burner provides low port loading. The structure provides good flame characteristics with low noise of combustion.

Abstract: A very high resolution laser gyroscope system having a phased-locked loop operatively coupled to one or more frequency difference outputs from a laser gyroscope cavity. Waves of at least four frequencies propagate around the gyroscope cavity, with output signals being formed having a frequency equal to the difference between the frequencies of wave pairs. In one set of embodiments of the invention, the frequency difference signal for one wave pair is phase-locked to an external reference source. A signal applied to a Faraday rotator bias coil provides the frequency shifting of the wave pairs necessary to achieve phase lock. The amplitude of the signal applied to the Faraday bias coil provides a highly precise measure of the rate of rotation. In another set of embodiments of the invention, one or more of the wave pair frequency difference signals are coupled as inputs to an external phase-locked loop in which a voltage controlled oscillator is followed by a frequency divider of the feedback circuit.

Abstract: A divider/combiner amplifier circuit divides input power through a sectored coaxial line to a plurality of longitudinal parallel channels spaced around the circumference of a cylinder; the power in each channel is amplified by a semiconductor device; and the amplified power is combined in another sectored coaxial line. A microwave waveguide connected to the input and output of each amplifying device confines the microwave energy of the operating mode to the longitudinal channel formed by said waveguide. Each waveguide extends longitudinally along the cylinder and each is circumferentially spaced from its neighboring waveguide by a space which forms a cut-off waveguide to the operating mode.

Abstract: This system accepts compass outputs from a wide variety of compass output devices such as stepper and synchro devices having different coupling ratios, supply voltages and carrier frequencies. The system then, as part of a PPI radar system, electronically converts these compass outputs without the usual intermediary electromechanical devices into real-time analog reference signals properly phased with respect to the radar timing to provide an electronically stabilized PPI. This is achieved by comparing the points of equal amplitude of any two phases of gyro compass synchro output signals and using these major transition points to provide a digital code indicating the angular position of the gyro output shaft; a microprocessor then transforms the code, by comparison with a previously stored position code into coded position change signals which are then used to change a stored angular value, representing the course of the ship.

Abstract: A latching mechanism for retaining the cover of the compartment of a sonobuoy containing a parachute is described. The latching mechanism, when in a position which prevents the deployment of the parachute, extends beyond the periphery of the sonobuoy launching tube and thus prevents insertion of the sonobuoy into the launching tube. The latching mechanism must be moved to a position which releases the cover before it allows insertion of the sonobuoy into the launching tube thereby insuring deployment of the parachute after the sonobuoy has been ejected from the launching tube. The latching mechanism is a planar structure rotatably connected to the cover and rotates in a plane parallel to that of the plane of the cover. The resulting latching mechanism may be applied to sonobuoys without the necessity for modifying the launching tube structure used for prior art sonobuoys.

Abstract: A method is disclosed to fabricate a cathode electrode for a continuous wave magnetron so that the resulting product is relatively free from random frequency modulation and frequency "pushing". The method generally comprises the steps of forming, from a slurry containing comminuted tungsten and thorium hydride, a cathode electrode of the desired shape and heat treating such cathode to remove all volatile elements and ultimately to form a cathode electrode made up of an eutectic mixture of tungsten and thorium particles of tungsten.

Abstract: A divider/combiner amplifier circuit divides input power through a sectored coaxial line to a plurality of longitudinal parallel channels spaced around the circumference of a cylinder; the power in each channel is amplified by a semiconductor device; and the amplified power is combined in another sectored coaxial line. A microwave waveguide connected to the input and output of each amplifying device confines the microwave energy of the operating mode to the longitudinal channel formed by said waveguide. Each waveguide extends longitudinally along the cylinder and each is circumferentially spaced from its neighboring waveguide by a space which forms a cut-off waveguide to the operating mode.

Abstract: A rail launcher for a guided missile is shown to include a pair of movable sections, each actuable first to form a gap in an otherwise continuous rail for receiving a lug affixed to a guided missile and then to return to an initial position, capturing such lug and forming a track.

Abstract: A tailbiter and open magnetron protection circuit for a radar pulse modulator having an extra winding on the modulator output transformer which combines a circuit to shorten a short range radar pulse with a circuit for applying a substantially constant load to the modulator when the magnetron is open or inactive. The extra winding on the transformer is connected in series with a saturable reactor which prevents shorting the desired short pulse width and stores undesired pulse energy in a capacitor and an SCR tailbiter circuit to short the excess pulse energy to ground in the interpulse period upon actuation of the SCR. Also included in the tailbiter circuit is an alternate path through a voltage divider and zener diode to the SCR gate which, whenever the magnetron is open or does not fire, a voltage build-up exceeding the zener voltage triggers the SCR gate circuit to maintain a substantially constant load on the primary of the modulation transformer.

Abstract: An improved slot array antenna with a circular aperture and linear polarization is shown to be made up of a plurality of slotted waveguides having different lengths and different widths. The slots in the waveguides are positioned to optimize amplitude taper in any plane passing through the center of the array normal to the surface thereof and to maximize the number of such slots.

Abstract: A microwave oven having a rotating radiator supported on a conductor extending through an aperture in a wall of the oven. The radiator is made up of a plurality of separate radiating elements supplied with microwave energy from said conductor via separate strip lines. A conductor of each of the strip lines rotates with the radiator and with respect to a ground plane which is common to all the strip lines and is formed by the wall of the oven containing the aperture. The radiating elements simultaneously radiate separate patterns into the oven.

Abstract: A method and apparatus for defrosting or removing ice from the outside of the evaporator of a refrigerator or heat pump. An additional inventory of refrigerant in thermal communication with a thermal mass is pressurized to substantially the same pressure as the condenser. After the compressor is deactivated at the end of a cooling cycle, a valve separating the inventory and evaporator is opened whereby the respective pressures rapidly equalize to an intermediate pressure. The inventory of refrigerant boils in the reduced pressure thereby drawing heat from the thermal mass to support the process. The vaporized refrigerant flows through the valve to the evaporator and condenses in the relatively cool environment. The heat given off by the condensation process melts ice on the outside of the evaporator.