Abstract: The present invention provides an economical yet effective system for the protection of the command link of ground controlled beacon tracking satellites. The invention includes means for detecting the amplitude and/or phase modulation of a composite signal which results from the beating of an intruder's carrier signal with an uplink beacon. A bandpass filter is included for guaranteeing that the low frequency sweep of the beacon signal and the high frequency data communication signals are passed through the receiver without interference. The resulting output of the bandpass filter corresponds to the intruder's carrier. This signal is rectified to provide a DC signal. A first comparator is provided for comparing the output of the detector to a first threshold which gives an indication as to whether or not the intruder is attempting to saturate an intermediate frequency (IF) stage of the satellite's receiver. A second comparator is provided for comparing the above-identified DC signal to a second threshold.

Abstract: The invention provides a two-channel liquid crystal light valve image projection system with prepolarization using an oil coupled optical arrangement. A prepolarizing beam splitter is mounted the container in optical alignment with a first surface for splitting and prepolarizing light from a source into first and second beams having first and second polarization states respectively. First and second dichroic separators are mounted within the container for extracting light of a first color from the first beam and light of a second color from the second beam respectively. The separator outputs are recombined by the prepolarizing prism into a single beam which is directed to a second polarizing beam splitter mounted within the container. The second beam splitter splits the single beam and directs light of the first and second polarizations through the second and third apertures, respectively.

Abstract: The body of the disclosed fuse includes connective portions having surface-metalization to which corresponding connective portions of the fusible element are respectively bonded.A metalization-conducive ceramic may be more-specifically utilized for the fuse body, while those portions of the body which interface with the fusible element may additionally be contoured so as to lessen the severity of element-severance forces otherwise experienced.When the fuse's connective portions yet-more-specifically comprise the opposite ends of a fuse body which is elongated, end caps may be electrically joined to the surface-metalized fuse ends. An enhanced degree of mechanical stability may also be achieved by further providing stabilizing geometrical expedients for the fuse/cap interface.

Abstract: A hybrid coupler is of the type known as a transverse electromagnetic mode, coupled transmission line coupler. The hybrid coupler is formed within a plate of metal by milling out channels of square cross-sections therein. The walls of the channels serve as outer conductors of coaxial lines, there being inner conductors of square cross-section positioned within the channel. A diagonally disposed window crosses the intersection of the ports and includes a separator. The central conductors of the respective coaxial lines are joined by diagonally disposed segments of inner conductor such that each pair of coaxial lines is so joined. Each pair of lines provides a pair of ports. The line segments are spaced apart by a spring-loaded separator for rigidly maintaining a coupling distance.

Abstract: Conductive coating (20) is produced by the process of first mixing by high shear mixing a mixture of 0.03 parts per weight of carbon black together with 0.003 to 0.01 parts per weight of wetting agent and 20 parts of solvent, and further mixing in by low shear mixing 1/2 to 1 part per weight of thermosetting resin. Prior to application this is then sprayed into place on the substrate. In this particular case, the substrate is exterior face sheet (12) of honeycomb structure (10) which may serve as part of a spacecraft, to electrically conduct away surface charges.

Abstract: A crossover for a microwave circuit constructed within a plate includes intersecting square-shaped coaxial transmission lines, each of which is formed by machining channels within the plate, with square-shaped central members disposed along the axes of the channels and insulated from the side walls thereof. The plate is made of an electrically conducting material to provide for the structure of a coaxial line of which the members thereof have a rectangular, preferably square-shaped, cross-section. At the intersection of two of the transmission lines, a septum is placed, the septum being parallel to the plane of the plate. The septum is located halfway between the top and the bottom portions of the channels. An inner, or central, conductor segment of reduced cross-section is slung beneath the termini of rod-shaped members in one line so as to pass beneath the septum and to provide for the structure of a coaxial transmission line beneath the septum.

Abstract: An adapter of a coaxial transmission line to a waveguide is provided for connecting the waveguide to a microwave circuit of coaxial lines which is formed by milling out the lines within a plate of a soft metal. The coaxial transmission lines are of rectangular, preferably square, cross-section with the outer conductors thereof being provided by the walls of the channel. The inner conductors of the coaxial lines are rod-shaped, the inner conductors also being of rectangular or square cross-section. An aperture is provided in an outer wall of the coaxial line. A stem connects with an inner conductor and passes through the aperture to extend outwardly therefrom. A waveguide is positioned with its propagation axis parallel to the stem, the waveguide enclosing the stem and being secured to the outer walls of the coaxial lines. The stem is placed adjacent the inner wall of the waveguide, but spaced apart therefrom to support a transverse electromagnetic wave.

Abstract: An adaptive, recursive frequency offset tracking system for effectively acquiring and tracking coherent as well as noncoherent electromagnetic data signals transmitted with or without countermeasure protection. The invention includes circuitry for eliminating the carrier frequency and generating complex samples of the baseband signal. The invention compares the phase of a sample to that of the previous sample to extract signals representing the phase difference between the two. The signals representing the phase difference are then converted to phasor signals and filtered to eliminate any noise component. The phase difference signals are derived from the phasor signals and accumulated to derive signals representing the frequency offset of the received data signal. The frequency offset signal is then provided to a phase shifter to correct for the effect of Doppler shift on the received data signal.

Abstract: A charge transfer differentiator having a layer of semiconductor material and a contiguous film of overlying electrically insulating material includes a first electrode fed by a first voltage wherein the first electrode is embedded in the film, for establishing an electric potential at the interface between the film and layer. A second electrode fed by a second voltage and a third electrode fed by a third voltage are embedded in the film and charge-coupled to the first electrode for establishing potential barriers at said interface. These electrodes and voltages provide a potential well at the interface. Also included is a fourth electrode embedded in the layer fed by a fourth voltage, and a fifth and sixth electrode separated from each other and embedded in the film, wherein the fifth and sixth electrodes are fed by a clock voltage, the fourth, fifth and sixth electrodes are charge-coupled to the second electrode so as to provide a constant input charge to the potential well.

Abstract: An optical arrangement is disclosed which provides color selective prepolarization of the light incident upon two or more light valves. This is accomplished by the use of a prepolarizing prism which acts on light from a light source to direct light of a first polarization to a first dichroic separator and light of a second polarization to a second dichroic separator. Each separator transmits an output beam having substantially a single color and a single polarization state. The two resulting beams are recombined by a dichroic adder prior to being applied to a second polarizing prism. The second polarizing prism directs light of a first color and polarization to a first light valve and light a second color and polarization to a second light valve. The result is that one light valve sees light of a first color and a first polarization and the other light valve sees light of a second color and second polarization.

Abstract: In the disclosed image-analysis scheme, a processing window of M by N pixels is successively scanned in single-pixel steps over a sensed image, with the centroid of the image data contained in each window position then being determined. When a pixel-by-pixel tabulation is made of the number of times each pixel has been determined to be the windowed-data centroid, those pixels having the higher tabulated centroid counts will tend to be the intra-image locations of any objects which are smaller than about M/2 by N/2 pixels.

Abstract: An internal calibration system is provided for use with a direction finding interferometer which comprises a plurality of receiving antenna elements (A.sub.1, A.sub.2), a local oscillator (20), a master receiving channel means (41), a receiving channel means (42), and a phase meter (92). The internal calibration system comprises a master switch (22), a master power divider and switch assembly (31), a power divider and switch assembly (32), two transmission lines (M.sub.1, M.sub.2) connected to the master switch assemblies (31, 32), an inter-channel transmission line (T.sub.12) connected to the master power divider and switch assembly (31) and to the other power divider and switch assembly (32), and a plurality of couplers (51, 52).

Abstract: Hydrazine thruster 10 is mounted on support flange 14 with thermal mass 12 therebetween. The thermal mass 12 extracts sufficient heat so that the incoming hydrazine in inlet line 20, as well as that portion of the decomposition catalyst contained within the inlet portion of chamber housing 24, is maintained at a temperature below the hydrazine saturation temperature at the pressure within chamber housing 24 so that at any on/off operating duty cycles for that installation, the hydrazine is discharged into the catalyst in chamber housing 24 as liquid.

Abstract: An electromagnetic filter assembly comprises a transmission line electromagnetically coupled to a dual mode resonator having a means for differentially tuning the two modes. The filter may be incorporated in a microwave integrated circuit, and the tuning means may be a movable dielectric slab asymmetrically disposed on the resonator.

Abstract: The present invention provides an improved microwave integrated circuit filter for electromagnetic waves. The filter includes a waveguide and three, four or more resonators spaced from one another and extending from the waveguide. Means, which may include a conductive ribbon, are provided electromagnetically coupling nonadjacent resonators.

Abstract: This invention provides a simple system for simultaneous raster scan display of video and alpha-numeric data on a single screen with provision for periodic image refreshment. It includes means for encoding the electrical signals representing the spatial intensity distribution of the video signal and the alpha-numeric signal. The coded signals are stored in a single bit map memory at the desired addresses. For display, the information is simply read from the memory through a single digital-to-analog convertor.

Abstract: An improved missile guidance system is provided which automatically compensates for jitter motion of the optical sight of a video tracker. The invention is adapted to receive video data input from an infrared detector or conventional camera. The invention includes circuits for filtering, gating, and digitalizing the incoming data as well as a formatter for directing successive frames into memory. Two memories are provided; the contents of which are sampled by matching logic as the second memory is being loaded. The matching logic thereby compares one frame of data to another at plurality of positions and provides a signal to an address latch when the best match is obtained. The format circuitry provides the position information to the address latch where it is stored for further processing. The output of the address latch is filtered to eliminate any signals representative of intentional tracking motion.

Abstract: An enhancement-mode field effect transistor (ENFET) logic circuit providing greater fan-out capability. The logic circuit employs a conventional common-source inverter section, but additionally incorporates a current-driving section which drives the common-source inverter section. A current-driven inverter logic circuit is realized by employing a second ENFET transistor to drive the gate of the common-source inverter section. A current-driven NOR gate is realized by employing two ENFET transistors in parallel which drive the common-source inverter section. Also a current-driven NAND gate is realized by utilizing a single transistor having two gate inputs to drive the common-source inverter section. The use of sweep-out circuitry allows for control of the operational speed of the device. The logic circuit designs have high fan-out capability compared to the common-source inverter circuit alone.

Abstract: A supplementary frequency acquisition circuit in the form of a frequency difference detector called a single sideband quadricorrelator is provided. When used in conjunction with a phase-locked loop of a conventional spread spectrum demodulator, this circuit allows for the rapid acquisition and accurate tracking of the center frequency of a spread spectrum suppressed-carrier bi-phase PSK signal. The invention cancels spurious sum and difference frequency components impulsed at the data rate as well as double difference frequency component and other modulation products without filtering. By eliminating the need for supplementary low pass filtering, the present invention provides rapid acquisition of the suppressed-carrier signal and provides a frequency difference output at twice the amplitude of comparable prior art systems. The tracking error or frequency difference (.omega..sub.i -.omega..sub.o) is obtained by differentiating the quadrature signal and multiplying by the in-phase signal component rotated 180.

Abstract: A biconical antenna, the halves of which are connected together at the apex by a pair anti-parallel diodes through a pair of parallel conductive whiskers or wires. A pair of quasi-optical lenses focuses energy from a local oscillator and from a submillimeter radio source, respectively, onto the diode pair in the end-fire and broadside direction, respectively. The diode pair spacing is equal to the half wavelength of the local oscillator energy. The local oscillator energy is common mode rejected and causes the incoming radio energy to be sampled by forward biasing the anti-parallel diode pair in synchronism with each zero crossing of the local oscillator energy. Accordingly, the local oscillator energy and noise virtually do not affect the current flow between the halves of the biconical antenna. The current flow represents an intermediate frequency signal corresponding to the difference in frequency between the incoming radio signal frequency and the local oscillator frequency.