Abstract: An apparatus has a Radio Frequency (RF) signal generator to produce RF signals phase shifted relative to one another in accordance with RF frequency waveform parameters. Amplifier chains process the RF signals to produce channels of amplified RF signals. Each amplifier chain has amplifiers and at least one amplifier has a tunable gate voltage synchronized with the RF signals.

Abstract: An apparatus has a Radio Frequency (RF) signal generator to produce RF signals phase shifted relative to one another in accordance with RF frequency waveform parameters. Amplifier chains process the RF signals to produce channels of amplified RF signals. Each amplifier chain has amplifiers and at least one amplifier has a tunable gate voltage synchronized with the RF signals.

Abstract: An array of antennae includes a monobit transmitter to insert dither into a transmit signal to form a dithered transmit signal. Monobit receivers process received signals that are combined with the dithered transmit signal to form composite received signals. Digital down converters process the composite received signals to form down converted received signals. A beamformer circuit processes the down converted received signals to form recovered signals.

Abstract: An array of antennae includes a monobit transmitter to insert dither into a transmit signal to form a dithered transmit signal. Monobit receivers process received signals that are combined with the dithered transmit signal to form composite received signals. Digital down converters process the composite received signals to form down converted received signals. A beam former circuit processes the down converted received signals to form recovered signals.

Abstract: An array of antennae includes a monobit transmitter to insert dither into a transmit signal to form a dithered transmit signal. Monobit receivers process received signals that are combined with the dithered transmit signal to form composite received signals. Digital down converters process the composite received signals to form down converted received signals. A beam former circuit processes the down converted received signals to form recovered signals.

Abstract: An apparatus has a Radio Frequency (RF) signal generator to produce RF signals phase shifted relative to one another in accordance with RF frequency waveform parameters. Amplifier chains process the RF signals to produce channels of amplified RF signals. Each amplifier chain has amplifiers and at least one amplifier has a tunable gate voltage synchronized with the RF signals.

Abstract: A thermal barrier layer (20) is formed by exposing an oxide ceramic material to a thermal regiment to create a surface heat affected zone effective to protect an underlying structural layer (18) of the material. The heat affected surface layer exhibits a lower strength and higher thermal conductivity than the underlying load-carrying material; however, it retains a sufficiently low thermal conductivity to function as an effective thermal barrier coating. Importantly, because the degraded material retains the same composition and thermal expansion characteristics as the underlying material, the thermal barrier layer remains integrally connected in graded fashion with the underlying material without an interface boundary there between.

Abstract: An article comprising a ceramic material having a ceramic matrix composite backing adapted for use in a gas turbine engine is provided. The article comprises a structural ceramic material having a hot side facing toward a high temperature environment and a cold side facing away from the high temperature environment; and a ceramic matrix composite composition having a strength greater than the strength of the ceramic material attached to the back of the cold side of the ceramic material, whereby crack initiation and propagation are inhibited by the ceramic matrix composition to a greater degree than by the ceramic material.

Abstract: A stacked ceramic matrix composite lamellate assembly (10) including shear force bearing structures (48) for resisting relative sliding movement between adjacent lamellae. The shear force bearing structures may take the form of a cross-lamellar stitch (50), a shear pin (62), a warp (90) in the lamellae, a tongue (104) and groove (98) structure, or an inter-lamellar sealing member (112), in various embodiments. Each shear force bearing structure secures a subset of the lamellae, with at least one lamella being common between adjacent subsets in order to secure the entire assembly.

Abstract: A component (10) for a gas turbine engine formed of a stacked plurality of ceramic matrix composite (CMC) lamellae (12) supported by a metal support structure (20). Individual lamellae are supported directly by the support structure via cooperating interlock features (30, 32) formed on the lamella and on the support structure respectively. Mating load-transferring surfaces (34, 36) of the interlock features are disposed in a plane (44) oblique to local axes of thermal growth (38, 40) in order to accommodate differential thermal expansion there between with delta alpha zero expansion (DAZE). Reinforcing fibers (62) within the CMC material may be oriented in a direction optimized to resist forces being transferred through the interlock features. Individual lamellae may all have the same structure or different interlock feature shapes and/or locations may be used in different groups of the lamellae. Applications for this invention include an airfoil assembly (10) and a ring segment assembly (82).

Abstract: Embodiments of the invention relate to a turbine vane having a fail safe cooling system. According to embodiments of the invention, the vane can have multiple concentric layers of radial cooling holes extending about the vane; each layer being fluidly connected to the adjacent layer or layers. Such fluid communication can occur through one or more plenums in the vane or in the shrouds bounding the radial ends of the vane. Coolant can initially be supplied to the innermost layer of cooling holes. From there, the coolant can sequentially progress through successive outer layers. Between two adjacent layers, the coolant can flow in opposite directions. Not only does such a system provide needed cooling to the vane, but the multilayer redundant cooling system can avoid or delay catastrophic failures that can occur if the vane surface is damaged, such as by impact.

Abstract: Embodiments of the invention relate to a robust turbine vane made of stacked airfoil-shaped CMC laminates. Each laminate has an in-plane direction and a through thickness direction substantially normal to the in-plane direction. The laminates have anisotropic strength characteristics in which the in-plane tensile strength is substantially greater than the through thickness tensile strength. Thus, the laminates can provide strength in the direction of high thermal gradients and, thus, withstand the associated high thermal stresses. The laminates are relatively weak in through thickness (interlaminar) tension, but, in operation, relatively low through thickness tensile stresses can be expected. The laminates can be strong in through thickness compression; accordingly, the laminate stack can be held in through thickness compression by one or more fasteners.

Abstract: An article comprising a ceramic material having a ceramic matrix composite backing adapted for use in a gas turbine engine is provided. The article comprises a structural ceramic material having a hot side facing toward a high temperature environment and a cold side facing away from the high temperature environment; and a ceramic matrix composite composition having a strength greater than the strength of the ceramic material attached to the back of the cold side of the ceramic material, whereby crack initiation and propagation are inhibited by the ceramic matrix composition to a greater degree than by the ceramic material.

Abstract: A vane assembly for a turbine assembly includes an inner endcap, an outer endcap, and a body. The body includes a metallic core assembly, a ceramic shell assembly and a support assembly. The metallic core assembly is coupled to the inner and outer endcaps and bears most of the mechanical loads, including aerodynamic loads. The ceramic shell bears substantially all of the thermal stress placed on the vane assembly. The support assembly is disposed between the metallic core assembly and said ceramic shell assembly and is coupled to the metallic core assembly.

Abstract: Shrink fit sleeves 30 interposed between the hub 21 and the shaft 10 of a large rotating apparatus adapted for operation in an environment subject to severe cyclical loading as occasioned by large thermal transients, are provided with the property of having greater axial shear flexibility than radial flexibility and/or greater axial flexibility than that of the shrunk on component 21.

Abstract: A hub assembly for a centrifugal fan subjected to large transient thermal stresses is provided in which a pair of opposed hubs sandwich the inner peripheral margin of a disc-shaped fan plate, with the inner peripheral margin of the plate including a thickened ring portion to provide oppositely projecting annular shoulders at the outer periphery of the thickened ring portion, with the opposing hubs having annular recesses to receive the thickened ring portion and with the outer peripheries of the recesses in closely abutting relation with the shoulders to provide a shoulder-recess bearing area and with a plurality of fastener means extending through the hubs and through the thickened ring portion so that the shoulder-recess bearing area, which is located radially outwardly from the bearing stress areas at the bolt holes, largely receives the transient thermal stresses and therefore reduces the stress in the bolts and plate.