Abstract: An EHF array antenna backplate that integrates thermal cooling structure and signal processing structure together into one unified structure. In one embodiment, forced air is employed to conduct heat from active modules; while in another embodiment, embedded heat pipes are employed. The array backplate is made by using four layers. The layers are: a high density multichip interconnect board, a metal matrix composite motherboard, an integrated waveguide/cavity/cooling structure, and a metal matrix composite baseplate. Each module uses solder bumps to connect to the high density multichip interconnect board where DC power and control logic signal distribution takes place. The modules are soldered in four locations to the metal matrix composite motherboard through openings in the high density multichip interconnect board. EHF signals are coupled to the modules from a resonant cavity via probes that protrude through the high density multichip interconnect board.

Abstract: A radiometer system is disclosed, the system incorporating a cylindrical parabolic reflector and a plurality of radiation sensors disposed along the focal line of the reflector in a minimum redundancy array. Digital processing circuitry is connected to the output of the sensors for digitally processing signals using a cross-correlation signal processing and fast Fourier transform circuitry to generate image signals, the system providing reduced weight and increased signal integration time. Several embodiments of the system are disclosed including analog and digital versions having a multiplicity of antenna configurations.

Abstract: A spacecraft (100) such as a satellite, is shaped roughly in the form of a disk with a uniform height (104) such that a plurality of such spacecraft may be stowed for launch in a stack (204), thereby enabling a greater number of satellites to be launched simultaneously with a single launch vehicle (220). The flat-pack configuration results from the satellite having a base member (101) with first surface (102) and second surface (103) members abutting the top and bottom opposing major surfaces of the base member in a stowed configuration.

Abstract: An unfurlable antenna reflector comprises a rigid central truss (12) on which are pivotally mounted circumferentially spaced booms (18). A network of tensioning cables (24) interconnect the ends of the booms to define a reflector-supporting net when the booms are in their fully deployed position. The booms deploy sequentially, to minimize shock loading, and have lengthening means (22) which simultaneously extend the outer ends of the booms after all the booms have reached their deployed position. A flexible mesh-like reflector surface (20) is connected to the net and is formed into a predetermined non-planar shape by net-shaping secondary cables (30).

Abstract: A lightweight, low profile phased array antenna 10 is disclosed which includes an electromagnetically coupled integrated subarray in a multilayer structure with no vertical electrical connections and no phase shifters. The integrated subarray includes a first layer 11 having an array of patches 20 of electrically conductive material. A second layer 15, is provided, in parallel registration with the first layer 11, which includes an array of resonators 22, each resonator 22 being electromagnetically coupled to a corresponding patch 20 in the first layer 11. A third layer 19 is provided which is in parallel registration with the second layer 15. Electromagnetic couplers 24 and 34 in the second and third layers 15 and 19 couple energy received by resonators 22 in the second layer 15, to processing circuitry in the third layer 19. The antenna of the present invention is adapted for transmit and receive modes of operation.

Abstract: A method of fabricating a polarizing dish antenna reflector (10) wherein a light source (22) is employed to pyrolyze an organometallic compound (14) disposed on the antenna surface to form grid elements (24) directly thereon. The surface of the parabolic dish antenna reflector (10) is coated with an organometallic compound (14) that comprises a metallic component such as gold, silver, copper chrome, or other suitable metal. The coated surface may be conditioned by depositing a surface film of polyimide, or the like. The coated surface is then pyrolyzed by using a high intensity focussed light source (22), such as a laser or discharge lamp to form metal grid lines (24) on the surface. The light source (22) is scanned across the surface to create parallel scan lines, or the light source may be fixed and the reflector surface can be moved relative to the light source (22) using a computer controlled XY table (16), or the like.

Abstract: Rear and forward reflector shells or dishes (36,38) are independently supported on a dynamically rigid truss structure (12) by means of separate studs extending from the forward nodes of the truss to the two shells. Forward node (22) carries adjustable rear shell stud (52) and independently carries adjustable forward shell stud (80). Both of the studs have flat portions oriented normal to the radius of the shell so that radial shell expansion due to temperature and temperature differential minimize shell distortion.

Abstract: A method of fabricating hollow square inner conductors having precise outer dimensions is disclosed. A first "u" shaped slot (10) is machined in a base plate (12) and a cover plate (16) is then brazed to the sloted surface (18). The cover plate (16) is machined to provide a first wall (20) of desired thickness. Second and third slots (22, 24) are machined in the base plate (12) parallel to the first slot (10) on opposite sides thereof to provide second and third walls (26, 28) of the hollow conductor (38). A sacrificial metal (30) having a melting point below that of the base plate metal is cast into the second and third slots (22, 24). A fourth wall (36) is formed by machining material from the base plate face (32) opposite the slotted surface (18). The sacrificial metal (30) is then removed to provide the hollow inner conductor (38) having precise outer dimensions (A, B).

Abstract: A frequency selective surface having a fibrous ceramic material body and a metallic grid on a reflecting face thereof. The body is formed by bonding a mass of silicon dioxide fibers together at their intersection points, as with a fusing agent such as boron nitride in a sintering process, resulting in an array of fibers with cellular porosity intentionally distributed through the body to reduce its density. Other types of ceramic fibers can be used either alone or in combination with the silicon dioxide fibers. The grid is attached to the reflecting surface or deposited thereon. The frequency selective surface finds particular utility in satellite microwave communications satellites.

Abstract: An antenna reflector having a parabolically curved reflecting surface is formed of a cellular ceramic material having ceramic fibers fused together in a rigid cellular structure. The body is formed by bonding or fusing a mass of silicon dioxide fibers together at their points of intersection with a fusing agent such as boron nitride in a sintering process, resulting in a fused array of fibers with cellular porosity intentionally distributed through the body to reduce its density. Other types of ceramic fibers can be used either alone or in combination with the silicon dioxide fibers. The antenna reflector finds particular utility in parabolic antennas for satellite microwave communications systems.