Abstract: A radio frequency surface-aperture, including: a mechanical support structure configured for maintaining mechanical stiffness and strength at a selected temperature; thermal insulation having at least a single layer; one or more through-thickness waveguides located through a thickness of the mechanical support structure and thermal insulation; a cold-side mode coupler arranged to connect a designated cold side of the one or more through-thickness waveguides to an electronic subsystem device; and one or more surface-wave waveguides arranged as an RF antenna on a surface of the mechanical support structure in operative communication with the through-thickness waveguides.

Abstract: A radio frequency surface-aperture, including: a mechanical support structure configured for maintaining mechanical stiffness and strength at a selected temperature; thermal insulation having at least a single layer; one or more through-thickness waveguides located through a thickness of the mechanical support structure and thermal insulation; a cold-side mode coupler arranged to connect a designated cold side of the one or more through-thickness waveguides to an electronic subsystem device; and one or more surface-wave waveguides arranged as an RF antenna on a surface of the mechanical support structure in operative communication with the through-thickness waveguides.

Abstract: A three-dimensional heterogeneous integrated (3DHI) package includes: a plurality of electrically interconnected active layers stacked on each other and a cooling block at a lower end of the active layers. Each of the active layers includes a semiconductor element, and at least one of the active layers includes an embedded heat spreader. The cooling block has a plurality of cooling channels formed therein, and the cooling channels do not extend through any of the active layers.

Abstract: A microchannel cooling block includes: a base plate; a microchannel array including a plurality of thermally conductive plates connected to and extending from a surface of the base plate, the thermally conductive plates being aligned so that a highest or second highest thermally conductive axis thereof extends away from the surface of the base plate, adjacent ones of the thermally conductive plates being spaced apart from each other to form a plurality of microchannels between the thermally conductive plates, one of the microchannels being between each adjacent two of the thermally conductive plates; and a manifold connected to the thermally conductive plates, an interior of the manifold being in fluid communication with the microchannels in the microchannel array.

Abstract: An apparatus and related method are disclosed for compensation of an antenna and/or an antenna array located at a surface that experiences environmental conditions. The apparatus can include: an embedded compensation and/or calibration structure configured to be interrogated by an electromagnetic wave, to dynamically compensate for surface erosion, thermal expansion, and/or dielectric constant changes of a surface scattering antenna; and a processor configured to: receive measurements of the compensation and/or calibration structure to determine beam pointing for dynamically varying surface conditions and perform sensing and/or seeking observation.

Abstract: Some variations provide an additively manufactured article comprising a first region and a second region, wherein the first region is a solid region or a porous region, wherein the second region has a pore size larger than the first-region pore size, and wherein the first-region average permeability is lower than the second-region average permeability. Some variations provide a co-sintering method of making an architected material with regions having different permeabilities, in which different additive-manufacturing process parameters are applied to distinct regions of the structure. Other variations provide a wall-pinning method of making an architected material with regions having different permeabilities, in which additive-manufacturing process parameters are selected to sinter pinned feedstock powder between solid walls. Engineered structures with controlled permeability, integrated manifolds, and arbitrary geometries are disclosed, without the requirement of complex manufacturing.

Abstract: Some variations provide an additively manufactured article comprising a first region and a second region, wherein the first region is a solid region or a porous region, wherein the second region has a pore size larger than the first-region pore size, and wherein the first-region average permeability is lower than the second-region average permeability. Some variations provide a co-sintering method of making an architected material with regions having different permeabilities, in which different additive-manufacturing process parameters are applied to distinct regions of the structure. Other variations provide a wall-pinning method of making an architected material with regions having different permeabilities, in which additive-manufacturing process parameters are selected to sinter pinned feedstock powder between solid walls. Engineered structures with controlled permeability, integrated manifolds, and arbitrary geometries are disclosed, without the requirement of complex manufacturing.

Abstract: A thermal protection system includes: an outer skin; a thermally insulating material under the outer skin; and a high temperature radio frequency (RF) aperture. The RF aperture includes a plurality of waveguides separated from each other and extending through the outer skin and the thermally insulating material.

Abstract: In some variations, an interferometric frequency-reference apparatus comprises: an atom source configured to supply neutral atoms; a collimator configured to form a collimated beam of the neutral atoms; one or more probe lasers; and a Doppler laser configured to determine a ground-state population of the neutral atoms. Other variations provide a method of creating a stable frequency reference, comprising: forming a collimated beam of neutral atoms; illuminating the neutral atoms with first and second probe lasers; adjusting the frequencies of the first probe laser and second probe laser using Ramsey spectroscopy to an S?D transition of the neutral atoms; and determining a ground-state population of the neutral atoms with another laser. The interferometric frequency-reference apparatus may provide an optical frequency reference or a microwave frequency reference.

Abstract: In some variations, an interferometric frequency-reference apparatus comprises: an atom source configured to supply neutral atoms to be ionized; an ionizer configured to excite the neutral atoms to form ionized atoms; an ion collimator configured to form a collimated beam of the ionized atoms; probe lasers; and a Doppler laser configured to determine a ground-state population of the ionized atoms, wherein the atom source, the ionizer, and the ion collimator are disposed within a vacuum chamber. Other variations provide a method of creating a stable frequency reference, comprising: forming ionized atoms from an atomic vapor; forming a collimated beam of ionized atoms; illuminating ionized atoms with first and second probe lasers; adjusting the frequencies of the first probe and second probe lasers using Ramsey spectroscopy to an S?D transition of ionized atoms; and determining a ground-state population of the ionized atoms with another laser.

Abstract: An imaging sensor package includes: an imaging sensor; and an architected substrate coupled to a bottom surface of the imaging sensor. The architected substrate has local stiffness variations along an in-plane direction of the architected substrate, and the imaging sensor and the architected substrate are curved.

Abstract: An imaging sensor package including: an imaging sensor; and a patterned substrate coupled to a surface of the imaging sensor. The imaging sensor and the patterned substrate being curved. The patterned substrate having a petal-shaped patterned area having a first thickness and a base substrate having a second thickness, the first thickness being greater than the second thickness.

Abstract: In some variations, an interferometric frequency-reference apparatus comprises: an atom source configured to supply neutral atoms; a collimator configured to form a collimated beam of the neutral atoms; one or more probe lasers; and a Doppler laser configured to determine a ground-state population of the neutral atoms. Other variations provide a method of creating a stable frequency reference, comprising: forming a collimated beam of neutral atoms; illuminating the neutral atoms with first and second probe lasers; adjusting the frequencies of the first probe laser and second probe laser using Ramsey spectroscopy to an S?D transition of the neutral atoms; and determining a ground-state population of the neutral atoms with another laser. The interferometric frequency-reference apparatus may provide an optical frequency reference or a microwave frequency reference.

Abstract: A hierarchical heat exchanger manifold includes: first and second fluid passages respectively open to an inlet and an outlet in a first level of the heat exchanger manifold; a plurality of first and second fluid passages in a second level of the heat exchanger manifold; and a plurality of first and second fluid passages in a third level of the heat exchanger manifold. A number of the first fluid passages in the third level is greater than a number of the first fluid passages in the second level. Each of the first fluid passages in the second level is in fluid communication with the inlet and at least one of the first fluid passages in the third level, and each of the second fluid passages in the second level is in fluid communication with the outlet and at least one of the second fluid passages in the third level.

Abstract: In some variations, an interferometric frequency-reference apparatus comprises: an atom source configured to supply neutral atoms to be ionized; an ionizer configured to excite the neutral atoms to form ionized atoms; an ion collimator configured to form a collimated beam of the ionized atoms; probe lasers; and a Doppler laser configured to determine a ground-state population of the ionized atoms, wherein the atom source, the ionizer, and the ion collimator are disposed within a vacuum chamber. Other variations provide a method of creating a stable frequency reference, comprising: forming ionized atoms from an atomic vapor; forming a collimated beam of ionized atoms; illuminating ionized atoms with first and second probe lasers; adjusting the frequencies of the first probe and second probe lasers using Ramsey spectroscopy to an S?D transition of ionized atoms; and determining a ground-state population of the ionized atoms with another laser.

Abstract: An imaging sensor package includes: an imaging sensor; and an architected substrate coupled to a bottom surface of the imaging sensor. The architected substrate has local stiffness variations along an in-plane direction of the architected substrate, and the imaging sensor and the architected substrate are curved.

Abstract: A hierarchical heat exchanger manifold includes: first and second fluid passages respectively open to an inlet and an outlet in a first level of the heat exchanger manifold; a plurality of first and second fluid passages in a second level of the heat exchanger manifold; and a plurality of first and second fluid passages in a third level of the heat exchanger manifold. A number of the first fluid passages in the third level is greater than a number of the first fluid passages in the second level. Each of the first fluid passages in the second level is in fluid communication with the inlet and at least one of the first fluid passages in the third level, and each of the second fluid passages in the second level is in fluid communication with the outlet and at least one of the second fluid passages in the third level.

Abstract: The present invention relates to a micro-lattice and, more particularly, to an ultra-light micro-lattice and a method for forming the same. The micro-lattice is a cellular material formed of interconnected hollow tubes. The cellular material has a relative density in a range of 0.001% to 0.3%, and a density of 0.9 mg/cc has been demonstrated. The cellular material also has the ability to recover from a deformation exceeding 50% strain.

Abstract: The present invention relates to a micro-lattice and, more particularly, to an ultra-light micro-lattice and a method for forming the same. The micro-lattice is a cellular material formed of interconnected hollow tubes. The cellular material has a relative density in a range of 0.001% to 0.3%, and a density of 0.9 mg/cc has been demonstrated. The cellular material also has the ability to recover from a deformation exceeding 50% strain.