Abstract: A system and method for reworking a flip chip includes use of a mill to remove an old flip chip, and a pick-and-place device for putting a new flip chip in place at the same location. The process may be automated, with the removal and the placement occurring sequentially without need for operator intervention. Other devices and processes may be part of the system/machine and process, for example cleaning following the milling, fluxing prior to the placement, and heating to cause solder reflow, to secure the new flip chip in place. Underfill may be employed to make for a more mechanically robust mounting of the new flip chip.

Abstract: A system and method for reworking a flip chip includes use of a mill to remove an old flip chip, and a pick-and-place device for putting a new flip chip in place at the same location. The process may be automated, with the removal and the placement occurring sequentially without need for operator intervention. Other devices and processes may be part of the system/machine and process, for example cleaning following the milling, fluxing prior to the placement, and heating to cause solder reflow, to secure the new flip chip in place. Underfill may be employed to make for a more mechanically robust mounting of the new flip chip.

Abstract: A power amplifier structure having: a power divider for dividing power in a signal fed to an input port between a pair of output ports. Each one of a pair of amplifiers has: an input coupled to a corresponding one of the pair of power divider output ports; and an output. A power combiner is provided. Signals at the power divider output ports are fed to the inputs of the pair of amplifiers in a forward direction and then pass through the amplifiers in the forward direction towards the outputs of the pair of amplifiers. Connectors direct the signals at the amplifier outputs to the power combiners, the signal then passing through the power combiner to an output port in a direction opposite to the forward direction.

Abstract: A power amplifier structure having: a power divider for dividing power in a signal fed to an input port between a pair of output ports. Each one of a pair of amplifiers has: an input coupled to a corresponding one of the pair of power divider output ports; and an output. A power combiner is provided. Signals at the power divider output ports are fed to the inputs of the pair of amplifiers in a forward direction and then pass through the amplifiers in the forward direction towards the outputs of the pair of amplifiers. Connectors direct the signals at the amplifier outputs to the power combiners, the signal then passing through the power combiner to an output port in a direction opposite to the forward direction.

Abstract: A turnstile antenna element and balun for use in a phased array are described. The antenna includes a plurality of stacked bowtie radiators. Each stacked bowtie radiator includes a driven conductor and a passive conductor separated by a dielectric. The balun includes a central member having dielectric slabs symmetrically disposed on external surfaces thereof. At least one end of the balun is provided having a shape such that conductors on the dielectric slabs of the balun can be coupled to the driven radiator conductors.

Abstract: A mixed-signal, multilayer printed wiring board fabricated in a single lamination step is described. The PWB includes one or more radio frequency (RF) interconnects between different circuit layers on different circuit boards which make up the PWB. The PWB includes a number of unit cells with radiating elements and an RF cage disposed around each unit cell to isolate the unit cell. A plurality of flip-chip circuits are disposed on an external surface of the PWB and a heat sink can be disposed over the flip chip components.

Abstract: In one aspect, an active electronically scanned array (AESA) card includes a printed wiring board (PWB) that includes a first set of metal layers used to provide RF signal distribution, a second set of metal layers used to provide digital logical distribution, a third set of metal layers used to provide power distribution and a fourth set of metal layers used to provide RF signal distribution. The PWB comprises at least one transmit/receive (T/R) channel used in an AESA.

Abstract: A turnstile antenna element and balun for use in a phased array are described. The antenna includes a plurality of stacked bowtie radiators. Each stacked bowtie radiator includes a driven conductor and a passive conductor separated by a dielectric. The balun includes a central member having dielectric slabs symmetrically disposed on external surfaces thereof. At least one end of the balun is provided having a shape such that conductors on the dielectric slabs of the balun can be coupled to the driven radiator conductors.

Abstract: A MMIC flip chip mounted to a circuit board having an underfill material disposed between the MMIC and the circuit board and a barrier structure for preventing the underfill material from being disposed under an electronic device of the MMIC while providing a cavity under the electronic device.

Abstract: A MMIC flip chip mounted to a circuit board having an underfill material disposed between the MMIC and the circuit board and a barrier structure for preventing the underfill material from being disposed under an electronic device of the MMIC while providing a cavity under the electronic device.

Abstract: In one aspect, an active electronically scanned array (AESA) card includes a printed wiring board (PWB) that includes a first set of metal layers used to provide RF signal distribution, a second set of metal layers used to provide digital logical distribution, a third set of metal layers used to provide power distribution and a fourth set of metal layers used to provide RF signal distribution. The PWB comprises at least one transmit/receive (T/R) channel used in an AESA.

Abstract: A valve assembly for a dunnage bag wherein in one embodiment of the valve a valve diaphragm is mounted on a shaft and is supported by a mounting bar such that the valve diaphragm may be reciprocally moved from the closed position to the open position by a simple axial push on the valve shaft. The valve shaft is retained in the mounting bar in an orifice and the shaft diameter is enlarged at its end distant from the valve diaphragm so as to generate a frictional force fit or lock in the open position to facilitate the removal of air from the bag. The valve may be released form the friction lock by the air pressure of a recharged bag and/or by the manual movement of the valve diaphragm and shaft axially toward the open end of the valve assembly. In an alternate embodiment, the valve diaphragm is mounted to a valve stem that it rotationally and axially moveably connected to the valve body.

Abstract: A valve assembly for a dunnage bag wherein in the valve body a valve diaphragm is mounted on a shaft and is supported by a mounting bar such that the valve diaphragm may be reciprocally moved from the closed position to the open position by a simple axial push on the valve shaft. The valve shaft is retained in the mounting bar in an orifice and the shaft diameter is enlarged at its end distant from the valve diaphragm so as to generate a frictional force fit or lock in the open position to facilitate the removal of air from the bag. The valve may be released form the friction lock by the air pressure of a recharged bag and/or by the manual movement of the valve diaphragm and shaft axially toward the open end of the valve assembly.

Abstract: An apparatus for carrying by a diver while under water (and at the surface between dives) provides information useful for enabling the diver to ascend therefrom both expeditiously and safely in order to avoid decompression sickness. A corrosion-resistant ceramic transducer (60) provides an electrical capacitance responsive to the pressure of the water thereon, in an electronic circuit (52), comprising also a resistance (61), for providing a signal (at 53) responsive to the time constant therein and substantially unaffected by normally encountered variations in supply voltage. Electronic data processing means (40-51), responsive to the signal, computes the water pressure, the depth of the transducer (60) in the water, the minimum depth to which the diver can from there ascend safely, the minimum time within which the diver then can ascend safely to the surface of the water, and the elapsed time since the beginning of the dive. Displays (48, 49) provide indications to the diver of the computed values.

Abstract: A multi-ply dunnage bag is provided with an end closure which is both strong and easy to fabricate. The first wall of the dunnage bag has, at one end, an extension or flap on the end of each ply. The flaps on each ply of the first wall are segregated into pairs of adjacent flaps and the two flaps that make up each pair are secured together and folded over the end of the bag where they are inserted between two adjacent plies of the opposite, or second wall and wherein at least one of the flaps of each pair is secured to one of the plies of the second wall. An identical end closure is provided at the other end of the bag, but with the plies of the second wall having flaps folded over and secured to the first wall.

Abstract: An inflatable dunnage bag having a relatively thin-film, flexible, gastight bladder is provided with a fill valve device extending from the exterior of the bag to the interior of the bladder. The fill valve device includes a hollow housing which is mounted on one end by means of a flange to the outer surface of one wall of the bladder. Within the housing there is an orifice and a plug member which is spring-biased in sealing engagement against the orifice. The plug member extends beyond the end of the housing and into the bladder. A flange on the end of the plug member in the bladder is substantially parallel to, and spaced away from, the mounting flange/bladder wall interface to provide a separation of the bladder walls, to deflect the filling gas to prevent impingement upon the bladder wall opposite the housing, and to provide an anti-blowout stop thereby preventing the plug member from being blown out of engagement with the valve housing when the bag is subjected to high compressive loads.