Abstract: A fibrous packing material (210) is distributed throughout the interior space of a surge tank (118). The packing material (210) makes the compression and expansion of gas within the surge tank (118) relatively more isothermal as compared to an empty tank. Thus, a smaller volume tank can be used without sacrificing performance. As a result, the size and weight requirements of the surge tank (118 ) have been reduced.

Abstract: A cross-point switch fabric slice (100) includes multistage gated buffer tree (135) incorporating at least first and second serially connected gated buffer stages (136, 138). N inputs (102-116) connect to preselected gated buffers (146-160) in the first gated buffer stage (136). The multistage gated buffer tree provides a signal path from any of the N inputs (102-116) to at least one switch output (118) in response to gated buffer stage control signals for the first gated buffer stage (136) and gated buffer stage control signals for the second gated buffer stage (138). Generally, the number of gated buffers decreases from that of the previous stage. As an input signal propagates through the cross-point switch fabric slice (100), longer internal connections are driven by more capable buffers.

Abstract: A truss structure for supporting a membrane that is to be deployed in space, where the truss structure maintains the membrane sufficiently flat with uniform tension. The truss structure includes a circular perimeter truss and a transitional truss. The transitional truss includes a series of ties that are coupled to the perimeter truss and the membrane. When the truss structure is deployed, telescopic parts of the perimeter truss that are stowed in expansion cause the transitional truss to expand and pull the membrane into the flat configuration.

Abstract: An optical architecture for a high-energy laser that directs a collimated laser beam through an aperture stop at a desired angle. In one embodiment, the optical architecture includes a single tilt mirror and three stationary mirrors that direct the laser beam in one dimension. The laser beam is reflected off of the mirrors in the same plane and is reflected off of the tilt mirror three times. The first two reflections off of the tilt mirror translate the beam and the third reflection causes the beam to be directed at the desired angle. In another embodiment, the optical architecture includes a single tip-tilt mirror and eight stationary mirrors that direct the beam in two dimensions. The laser beam is reflected off of the mirrors in two planes and is reflected off of the tip-tilt mirror three times. The first two reflections off of the tip-tilt mirror translate the beam and the third reflection causes the beam to be directed at the desired angle.

Abstract: A laser diode package (10) according to the present invention is tolerant of short-circuit and open-circuit failures. The laser diode package (10) includes a laser diode bar (12), a forward-biased diode (14), a heat sink (18), and a lid (16) which may have fusible links (86). The laser diode bar (12) and the forward-biased diode (14) are electrically connected in parallel between the heat sink (18) and the lid (16). The emitting region of the laser diode bar (12) is aligned to emit radiation away from the forward-biased diode (14). Several packages can be stacked together to form a laser diode array (42). The forward-biased diode (14) allows current to pass through it when an open-circuit failure has occurred in the corresponding laser diode bar (12), thus preventing an open-circuit failure from completely disabling the array (42).

Abstract: An integrated packaging assembly for an MMIC that uses the semiconductor wafers on which circuit elements are fabricated as the package. The packaging assembly includes a plurality of semiconductor layers that have been diced from the semiconductor wafers, where the semiconductor layers can be made of different semiconductor material. The semiconductor layers define cavities therebetween in which circuit components are fabricated. A sealing ring seals the semiconductor layers together so as to hermetically seal the circuit components within the cavities.

Abstract: A system and a method for an ambient atmosphere ion thruster having a pair of permeable electrical members for accelerating ambient atmosphere ions which enter the thruster due to a craft's relative velocity. Neutral ambient atmosphere molecules in the intake mass flux may also be ionized and subsequently accelerated by the pair of permeable electrical members. Acceleration of any entering mass comprises an exhaust mass flux which then produces a net thrust. Such net thrust is then vectored by configuring and orienting the thrusters for imparting axial and lateral accelerations as well as pitch, yaw, and roll controls. The present invention is operational in proximity to any celestial body having a sensible atmosphere during a portion of the free trajectory or during orbiting at altitude. Useful net thrust is thereby produced without need for carrying reaction mass onboard a spacecraft.

Abstract: A satellite communication system and related method for collecting data in space and transmitting it to a processing center on the earth. The communication system includes at least one satellite orbiting the earth that has a device for collecting the data. The satellite transmits the data to a plurality of receive only terminals on the earth. The terminals process the signals and transmit the data on the communications link to the processing center.

Abstract: A method of dry plasma etching a semiconductor structure (20), having at least one semiconductor material layer (21), on a semiconductor wafer (200), involving a dry plasma reaction gas mixture (30i) being chemically selected for, and having an etch rate corresponding to, each semiconductor material layer (21); dividing the semiconductor structure (20) into a masked portion (23a) and an unmasked portion (23b); and sequentially exposing the unmasked portion (23b) of the semiconductor structure (20) to the dry plasma reaction gas mixture (30i).

Abstract: An improved etching process for creating dimensionally accurate sub-micron and micron via-openings is disclosed. Specifically, this invention discloses a via etching process for a polymer layer (24) deposited on a semiconductor substrate (28) comprising the steps of: placing the semiconductor substrate comprising a polymer layer (24) deposited on the semiconductor substrate, a hard-mask (30) deposited on the polymer layer (24) and a photoresist mask (32) deposited on the hard-mask (30). The invention further, discloses performing a hard-mask opening step (34) comprising releasing a first fluoride gas (36) into the chamber. Furthermore, performing a polymer etching step (40) comprising releasing a second fluoride gas (42) into the chamber is disclosed. The invention also includes a hard-mask removal and tapered via step (46) to increase process margin.

Abstract: Accordingly, this invention relates to an dry etching process for semiconductor wafers. More particularly, the present invention discloses a dry etching process including a halogen etchant (24) and a nitrogen gas (28) that selectively etches a compound semiconductor material (18) faster than the front-side metal layers (16A)(16B). Further, the dry etching process produces a vertical wall profile on compound semiconductor material (18) in both X (38) and Y (40) crystalline directions without undercutting the top of a via-opening.

Abstract: An electronically programmable multimode circuit is described. More particularly, the present invention is an electronically programmable multimode circuit that includes a first path and a second path wherein a mode and a signal directional flow direction is controlled through the selective biasing of the first path and the second path. A multimode circuit is produced that contains modes such as a phase shifter mode, an IQ modulation mode, an amplifier mode, a mixer mode, and a multiplier mode.

Abstract: A common source, bi-directional microwave amplifier is described. More particularly, the present invention is a microwave, common source, bi-directional amplifier that includes a first amplification path and a second amplification path wherein the signal directional flow is controlled through the selective biasing of the first amplification path and the second amplification path. Each amplification path is designed to optimize desired performance. For signal flow through the first amplification path, the first amplification path is biased-on and the second path is biased-off. For signal flow through the second amplification path, the second amplification path is biased-on and the first path is biased-off.

Abstract: A demodulator demodulates a modulated signal waveform in a data communication system. A phase tracking loop tracks the phase of said modulated signal waveform and having an inner block decoder configured to decode a set of vector pairs of the modulated signal waveform at a decode rate to generate associated codewords and phase estimates. A group of data symbols consisting of the first data symbols of the modulated signal waveform are run backwards through the phase tracking loop. An outer block decoder receives the associated codewords generated by said inner block decoder and utilizes and corrects only codewords associated with symbols after and including the group of data symbols consisting of the first data symbols of the modulated signal waveform.