Abstract: A radio frequency circuit includes a first RF switch having a first common port coupled to an input port of the switch circuit and a first pair of branch ports and a second RF switch having a second common port coupled to an output port of the circuit and a second pair of branch ports. The radio frequency circuit further includes an RF propagation network having a first end coupled to a first one of said first pair of branch ports of said first RF switch and a second end coupled to a first one of said second pair of branch ports of said second RF switch. The radio frequency circuit further includes an RF termination having an impedance characteristic corresponding to an impedance characteristic of said first common port and having a first end coupled to a second one of said first pair of branch ports of said first RF switch and a second end coupled to a first reference potential.

Abstract: An amplitude monopulse direction finding system is disclosed. The system is built around a circular array with a circular lens in which the antenna elements and array ports are larger than in conventional systems. The oversized antenna elements and array ports provide a wide range of operating frequencies for the direction finding system. Additionally, the direction finding system contains an omni-directional probe at the center of the lens to detect the presence of signals. In an alternative embodiment, each array port is split into two halves which can be combined in different ways to produce different beam patterns, allowing the beam pattern providing the best signal to noise ratio to be selected. Also, built-in-test circuitry is described.

Abstract: A microwave oven having microwave absorbing material disposed in a top portion of the microwave oven cooking cavity above a grease shield. By absorbing reflected microwave radiation, this feature reduces the tendency of overcooked edges, particularly in low profile foods such as pizza. An additional feature includes a cylindrical member disposed around the microwave antenna to provide a directive pattern of microwave energy in the cooking cavity. The microwave oven provides improved cooking uniformity for foods such as pizzas or pies.

Abstract: A cryogenic signal coupling apparatus includes a laser which launches optical power into an integrated optical waveguide (IOW) within a cryogenic region via an imaging lens. This optical power is then equally split by a passive optical splitter, and fed to one or more 1.times.2 IOW devices. Within the cryogenic region, a plurality of infrared sensing photodiodes provide electrical signal outputs in response to optical stimuli, which signal outputs are amplified and selected by a multiplexing arrangement for application as the modulating signal to one of the 1.times.2 IOW's. Control electronics also within the cryogenic region supply timing and control information to the other electronics therein. The IOW's modulate their input optical power in accordance with their respective modulating electrical input signals, and provide differential optical outputs which are directed across the thermal barrier to individual differential optical receivers.

Abstract: An impedance matching and bias feed network for interfacing to a low noise amplifier of a receiver section of an electrically steered phased array antenna. The impedance matching and bias feed network includes an inductor and capacitor network for impedance transformation while providing in shunt with a 50 ohm input side of the network a gate bias path via the inductor to the low noise amplifier thereby substantially reducing the receiver noise figure.

Abstract: An improved dual polarized antenna element for use in planar array antennas. The antenna element includes a conductive sheet having a forwardly positioned notch and a pair of spaced rearwardly extending slot portions formed therein. The notch is adapted for coupling radio frequency energy between free space and the antenna element and the pair of slot portions are electrically coupled to the notch. A power divider/combiner is provided and is preferably interconnected with a power combiner/divider through branches of equal phase length. With this arrangement, reactive power divider induced off-axis scan blindness caused by an odd mode coupled field is prevented. Additionally, an antenna module comprising a pair of such antenna elements disposed in intersecting relationship is provided with a coincident phase center.

Abstract: A combined infrared-radar detection system wherein a radar antenna also serves as the primary mirror in an infrared focusing arrangement.

Abstract: A target tracking radar receiver for use in a semiactive tracking system wherein elevation angle data, azimuth angle data and Doppler frequency shift data are processed in a manner which enables narrow band filtering of target angle tracking data in the first intermediate frequency stage. The receiver is arranged to track, simultaneously, variations of target Doppler frequency and of transmitter frequency to permit the desired early narrow band filtering of the received angle data.

Abstract: A flexural transducer includes a hollow tube that is magnetically driven by a coil/magnet assembly. A magnetic field is provided by passing a current through the coil. The filed passes through an air gap between the coil and the magnet to attract and repel the magnet during alternating portions of the current's cycle. The magnetic transducer driver mechanism permits high drive capability, high temperature operation and provides lower frequency operation than conventional ceramic drivers.

Abstract: A calibration circuit includes a plurality of signal sources each of said signal sources having an output port and providing a signal having a known phase and a signal combiner circuit having a plurality of input ports and an output port with each of said input ports being coupled to a corresponding one of said signal source output ports. The calibration circuit further includes a switch having a common port and at least one branch port, said branch port being coupled to said output port of said signal combiner circuit and an analog to digital converter circuit having an input port coupled to the common port and an output port. The calibration circuit further includes a central processing unit coupled to the output port of said analog to digital converter and a summing circuit having a first input port coupled to said central processing unit, a second input port coupled to the output port of said analog to digital converter circuit and an output port.

Abstract: A compliant cover for use with acoustic source transducers includes a rubber boot bonded to a shell of the transducer. The cover has a groove molded within a surface thereof to allow the shell to expand and contract with reduced resistance. Conventional transducers having rigidly mounted covers disposed on the shell which resist the motion of the shell and decrease the overall efficiency of the transducer.

Abstract: An efficient power MOSFET resonant gate drive circuit having a large coupled inductor between and in series with two switching transistors. The inductor prevents cross-conduction from the power bus through the drive transistors as may be caused by simultaneous turn-on due either to switching delays or single-event-upset-radiation from energetic cosmic rays. In either case, the inductor presents a high impedance for current that tries to flow through both transistors simultaneously. A center tap on the inductor is connected to the gate of the power MOSFET. An equivalent inductance resonates with the equivalent capacitance of the gate of the power MOSFET providing fast turn-on of the power MOSFET. During turn-off of the power MOSFET, one drive transistor is switched-off and the other drive transistor is switched-on.

Abstract: An apparatus is disclosed for controlling the brightness of a matrix-addressed flat panel CRT display of a type having intersecting column and row conductors forming, respectively, the gate and cathode electrodes of a field electron emission array. The brightness control is effected by controlling the voltages applied to the drive lines of the intersecting conductors. A waveform having progressively increasing voltage steps is sequentially applied to the row conductors. The voltages at each of the steps are preferably selected to enable electron beam currents which provide brightness levels which are twice the brightness of the previous step. Binary-coded brightness control signals are simultaneously applied to all of the column conductors. The voltages of the stepped waveform and the binary-coded signals comprise a combination of video information data and correction data which compensate for irregularities in the current emitting structure at the selected conductors.

Abstract: A radar performance monitor (RPM) receives a transmitted radar signal from a radar system being monitored and couples the signal to a recirculating loop comprising a SAW delay line in order to produce a series of simulated radar return signals of equal amplitude and by using the same frequency as the received radar signal providing the frequency falls within a predetermined bandwidth of the SAW delay line. The simulated radar return signals are displayed at the radar system and used to evaluate the operation and calibration of a transmitter and the sensitivity and calibration of a transmitter and the sensitivity and calibration of a receiver in the radar system. The radar performance monitor is actuated at the option of a radar operator.

Abstract: A washing machine having the cabinet decoupled from the suspension system in order to eliminate undesirable resonance mode walking conditions. The cabinet is frictionally attached to the washer supporting feet. With this arrangement, the effect of the cabinet on the washer/floor natural frequency is eliminated, thereby increasing such natural frequency above the spin speed of the washer. In this way, walking typically occurring at the natural frequency (i.e. when the spin speed matches the natural frequency of the washer and floor system) is prevented. This arrangement further provides decreased cabinet vibration and noise during operation at typical spin speeds.

Abstract: A bulkhead for a tumbler clothes dryer wherein the bulkhead panel is stamped as a unitary part from a single metal blank on a progressive die. The bulkhead panel includes a cylindrical plug portion which fits inside the tumbler drum, and four mounting brackets each extending from a respective one of the four quadrants of the plug portion. Each mounting bracket includes a face portion, a leg portion, and a foot mounting portion. Drum bearings are connected to the bulkhead panel to form the bulkhead. The rear bulkhead mounts to the back panel of the cabinet, and the front bulkhead mounts to the front edges of the two cabinet side panels.

Abstract: A voltage regulator is provided for producing a predetermined output voltage level. The voltage regulator has a voltage source for providing a plurality of successively increasing voltage levels at a corresponding plurality of output terminals, or taps. A controller is provided for automatically selecting, in response to an electrical control signal, the one of the taps providing a voltage level above the predetermined output voltage level. In a preferred embodiment of the invention, the selected tap is the one of the plurality of taps producing a voltage level closest to, and greater than, the predetermined output voltage level. With such an arrangement, the electronic control signal allows a convenient way to select an output voltage level closest to, and greater in magnitude than, the predetermined voltage level, thereby improving the efficiency of the regulator.

Abstract: An optical beam steering device for use in a single-aperture laser transceiver system provides deflection of the transmitted and received beams in two planes, while maintaining the distinctive identities of each channel respective to their polarizations. The invention utilizes four single-dimensional beam deflecting devices, two for each orthogonal linear polarization of the two transceiver channels, one of these for each steering axis. In addition, a 90.degree. polarization rotator and a quarter-wave plate are included in the arrangement of beam deflecting devices to satisfy the polarization requirements of these devices and of the transceiver channels.

Abstract: An improved sonar signal processor and display combining the use of both coherent and incoherent signal processors. In addition to a conventionally used matched filter detection processor, an incoherent signal processor comprising a cross-range energy filter and a down-range energy filter is used. The cross-range energy filter detects objects characterized by a narrow bearing response; whereas the down-range energy filter detects objects characterized by a narrow range response. The detection events resulting from the incoherent signal processor are displayed in a subdued color to prevent distraction from the primary display events and to reduce the false alarm rate by allowing the sonar operator to view events in the context of natural boundaries.

Abstract: A ball bearing assembly with a spacer to prevent ball bearing failures. The spacer has a ring with a tongue that fits into a groove in a second spacer ring. One spacer ring is coupled to the outer ring of the ball bearing assembly and the other spacer ring is coupled to the inner ring of the ball bearing assembly. The spacer therefore allows relative rotation of the rings of the ball bearing assembly but prevents relative translation of the rings beyond a point which will damage the ball bearing assembly.