Abstract: A closed-loop system for precisely regulating the speed of an electrically driven rotating body. A tachometer rotor, mechanically linked to the rotating body, is provided with p "teeth " around its periphery. A sensor produces a pulse signal upon passage of each of these teeth, to generate a cyclical tachometer signal having a frequency p times the frequency of rotation. A tachometer counter counts this signal and produces a single output pulse after every n.times.p pulses from the sensor, such that the same one of the p teeth is responsible for triggering each of the successive output pulses, and variations in spacing between teeth do not cause variations in the period of the counter output. A high frequency clock is counted by a second counter, which transfers its count to a storage register and resets upon each pulse from the tachometer counter, such that the count held by the storage register is a continuously updated, highly accurate digital representation of the period of the rotating body.

Abstract: A lossless and matched dual mode network (10) in which the maximum voltage amplitudes (a, b, and c, respectively) appearing at three output ports (11, 12, 13), are preselected and are arbitrary subject only to the constraint that the sum of the squares of any two elements of the set (a, b, c) must be equal to or greater than the square of the third element of this set. The set of complex voltages (A, B, and C, respectively) appearing at the three output ports (11, 12, 13) when an input signal is applied to one of the input ports (1 or 2) is conjugate with the set of output voltages (AA, BB, and CC, respectively) appearing at the three output ports (11, 12, 13) when an input signal is applied to the other input port, which is isolated from the initially selected input port (1 or 2). The network (10), which may be used as a feed network in an antenna (25) system, e.g., as an even/odd mode network, comprises three 90.degree. couplers (31, 32, 33 ) and three phase shifters (41, 42, 43).

Abstract: An actuator (1) for mechanically supporting a structure such as an optical or radio telescope reflector (3). The actuator (1) is free to precess about a pivot point (C) which is fixed with respect to the supporting cell structure (9). This can be accomplished by gimballing the actuator (1) using vertical (13) and horizontal (17) trunnions. This gimballing arrangement permits radial and axial excursions of each actuator ball (29) to compensate for gravity vector variations as the reflector (3) is moved to point towards its target, and to compensate for thermal expansion variations between the reflector (3) and cell (9). Fine axial position adjustments are accomplished by a rotating nut (43) or a rotating screw (63) configuration in conjunction with a stepper motor (47 or 67). Motor (47 or 67) can receive its commands from a real-time closed loop system sensitive to axial position or axial load.

Abstract: A reconfigurable dual mode network (10) in which the maximum voltage amplitudes (a, b, and c, respectively) appearing at three output ports (11, 12, 13), are preselected, reconfigurable, and arbitrary subject only to the constraint that the sum of the squares of any two elements of the set (a, b, c) must be equal to or greater than the square of the third element of this set. The set of complex voltages (A, B, and C, respectively) appearing at the three output ports (11, 12, 13) when an input signal is applied to one of the input ports (1 or 2) is conjugate with the set of output voltages (AA, BB, and CC, respectively) appearing at the three output ports (11, 12, 13) when an input signal is applied to the other input port, which is isolated from the initially selected input port (1 or 2). The lossless and matched network (10), which may be used as a feed network in an antenna (25) system, e.g.

Abstract: Methods and apparatus are disclosed for monitoring and controlling potential residual stress relief mechanisms in composite epoxy resin materials. Passive and injected, or active, acoustic signals originating in or propagated through a specimen material during the formation process produce signatures identifiable with known residual stress relief mechanisms. Real-time control of material temperature and external pressure during formation in response to acoustic signals measured or observed in relation to desired acoustic signature minimizes formation of undesired material properties.

Abstract: A ceramic resonator element having high Q, high dielectric constant, and a low temperature coefficient of resonant frequency is enclosed within a cavity to form a composite microwave resonator having reduced dimensions and weight as compared to a simple cavity resonator. A pair of tuning screws extend into the cavity along orthogonal axes to tune the structure to resonance along these axes at frequencies near the fundamental resonance of the ceramic element. Several such cavities can be formed in a short length of waveguide by the use of transverse partitions at spaced intervals and coupling between cavities can be accomplished by using simple slot, cross or circular irises. In each cavity, a mode-perturbing screw is positioned along an axis 45.degree. from each of the orthogonal tuning screws, such that resonance along either of the orthogonal axes is coupled to excite resonance also along the other.

Abstract: Method for growing HgCdTe (15) upon a CdTe substrate (5) using a HgTe source (3) and close-spaced vapor phase epitaxy (CSVPE). A processing temperature T of between 520.degree. C. and 625.degree. C. is employed over a processing time t of between approximately 1/4 and 4 hours. The thickness A of the grown HgCdTe (15) is a linear function of processing time t. The mole fraction x of cadmium in the HgCdTe (15) is a linear function of temperature T and an exponential function of the mole fraction y of mercury in the source (3). The lower the relative amount of mercury in the source (3), the greater the relative amount of mercury in the end product (15), and vice versa. Any crystal plane and any axial orientation of the CdTe substrate (5) can be used without affecting the rate of growth of the HgCdTe (15), the single crystal nature of the HgCdTe (15), or the mirror-like finish of its surface.

Abstract: A coupling assembly for joining a guidance module housing to a bulkhead of a guided missile. The coupling assembly includes a plurality of levers extending through slots in the housing and bulkhead of the guided missile with a plurality of threaded fasteners extending through the levers and engaging a plate member integral with the housing. The threaded fastener is torqued to impart a pivoting motion to the lever about a fulcrum integral with the plate such that axial directed forces are transferred from the outer periphery of the lever to the housing which is forced to abut the bulkhead.

Abstract: Disclosed is a seal which provides effective hermetic sealing of insulated metallic feedthroughs in metallic containers. The device has particular applicability in the fabrication of pressurized metal/gas battery cells such as those used in spacecraft. A conductive terminus protrudes through a metallic vessel which may be pressurized. It is desired to maintain electrical separation between the terminus and the wall of the vessel by means of a dielectric, which is compressed between the terminus and a metallic boss to provide a hermetic seal. The compressive force is applied radially outwardly by means of drawing a nondeformable pin through a hollow cylindrical barrel constituting the terminus, thereby slightly deforming the barrel and grossly deforming the dielectric. The pin may be either pulled out of the barrel from within the vessel or pushed into the barrel from outside the vessel, but in each case force is applied radially outwardly in a gradual, relatively frictionless fashion.

Abstract: At least two oscillators (20) are power combined using planar transmission lines, e.g., microstrip, stripline, or suspended substrate. A portion (42) of each oscillator (20) is preferably implemented in suspended substrate while an impedance matching portion (24) is preferably implemented in microstrip. Each oscillator (20) comprises a two-terminal negative-resistance active device power source (22) such as a negative resistance diode. The sources (22) are all operated in phase in the even mode. Stabilizing resistors (8) connect adjacent oscillators (20) to keep the sources (22) in phase. A diplexer (29, 33) within each oscillator (20) isolates the RF output (and RF input when injection locking is employed) from the individual DC biases used for sources (22), controls out-of-band impedances, and isolates oscillators (20) from each other. The outputs of the oscillators (20) are summed at a common junction (12) via planar transmission line spokes (10) having equal lengths.

Abstract: This circuit measures both the resistance and the capacitance of the parallel RC circuit that is the equivalent of any substantially non-inductive two-port device. Thus, the circuit can measure any resistance, capacitance, RC network, or diode, including photovoltaic diodes. The invention uses an operational amplifier, an audio A.C. oscillator and a voltage measuring device such as a digital RMS voltmeter. The resulting apparatus is small, inexpensive, accurate, and easy to operate. The resistance is measured with the audio oscillator set for a low frequency (such as 70 Hz); the capacitance is measured when the audio oscillator is set at a high frequency (such as 20 KHz). The resultant values can either be calculated using simple formulas or can be displayed directly using an analog or digital circuit.

Abstract: A device and method for optimizing the weight and/or the heat transfer (conduction) capability of a heat transfer cylindrical sleeve. The sleeve is designed to fit around a cylindrical heat source. One particular application for this invention is where the heat source is a battery such as a metal gas battery in a satellite (where weight savings is important). Two sets of functional relationships are generated showing the relationship between the thickness of the sleeve at its top and bottom, an "area factor" (which is directly proportional to its heat transfer capability), the material thermal conductivity, and its volume per unit length (which is directly proportional to its weight). One can specify the desired heat transfer capability of the sleeve and optimize (minimize) its weight. Conversely, one can specify the desired weight for the sleeve and optimize (maximize) its heat transfer capability.

Abstract: A composite address resolution scheme is used in a distributed processing computer communications system. Many parallel processors are connected together via a multi-processor intertie bus, which serves to communicate data from any processor to any other processor. Resolution of control among several competing processors which desire access to the bus is resolved directly on the bus. The processors are online replaceable; and the system fails soft. Each processor contains resolution logic which enables simultaneous parallel resolution by any number of processors. The resolution is performed on the basis of a composite logical address (CLA) which originates within each processor. The CLA can contain non-unique priority information as well as unique logical location information. The bus is awarded to the processor exhibiting the lowest CLA. The resolution is performed starting with the most significant bit or bits and working downward towards the least significant bit or bits.

Abstract: A thin passivating layer (14) of CdTe is formed on a layer of photoconductive HgCdTe (4) by means of electrochemical deposition. The photoconductive layer (4) is used as a cathode. A first anode (26) is fabricated of tellurium and a second anode (28) is fabricated of an inert substance such as graphite. An electrolyte (30) comprises an aqueous solution of CdSO.sub.4 and unsaturated TeO.sub.2. Alternatively, electrolyte (30) can be saturated with TeO.sub.2, in which case a first anode is fabricated of an inert substance, and an optional second anode is fabricated of cadmium. After purifying the cathode (1) and the electrolyte (30), cadmium and tellurium are simultaneously deposited upon cathode (1). Stoichiometric balance is maintained to maximize the resistivity of the passivating CdTe layer (14). This is accomplished by regulating the deposition voltage of cathode (1) with respect to a saturated calomel electrode (22).

Abstract: A modular solar radiation concentrator consists of many identical reflective panels (1), each having the shape of a portion of the surface of a sphere. The panels (1) are mass produced, mounted between a pair of horizontal beams (2) so they can partially rotate about two orthogonal axes, and aligned as part of multi-beam (2) modules (3) on a test fixture so that all panels (1) reflect distant radiation upon a small aperture (36). Spaced occur between all panels (1) when mounted in the concentrator. The reflector support structure (4) has a finite number of identically angled bends so that the overall reflector (47) approximates the surface of a sphere. A solar radiation receiver (34) is hingedly suspended to the support structure (4) at the focal point of each of the panels (1). The reflector (47) is mounted upon an azimuth/elevation mount (6, 46), which rotates reflector (47) 360.degree. about a vertical azimuth axis and 90.degree. or more about an orthogonal elevation axis.

Abstract: A modular solar radiation concentrator consists of many identical reflective panels (1), each having the shape of a portion of the surface of a sphere. The panels (1) are mass produced, mounted between a pair of horizontal beams (2) so they can partially rotate about two orthogonal axes, and aligned as part of multi-beam (2) modules (3) on a test fixture so that all panels (1) reflect distant radiation upon a small aperture (36). Spaces occur between all panels (1) when mounted in the concentrator. The reflector support structure (4) has a finite number of identically angled bends so that the overall reflector (47) approximates the surface of a sphere. A solar radiation receiver (34) is hingedly suspended to the support structure (4) at the focal point of each of the panels (1). The reflector (47) is mounted upon an azimuth/elevation mount (6, 46), which rotates reflector (47) 360.degree. about a vertical azimuth axis and 90.degree. or more about an orthogonal elevation axis.

Abstract: A combiner for power combining electromagnetic energy is disclosed. At least two electromagnetic cavities are positioned having intercavity coupling among all cavities: each cavity is tangent to all other cavities and/or external transmission line connections are employed to enhance/provide intercavity coupling. Each cavity contains within it at least one power generating device. An input/output port is connected via a nonreciprocal device to an output load and an injecting oscillator which usually has a lower power level than that of the free-running combiner and a higher spectral purity. The cavities are intentionally tuned to at least two different frequencies. For the two cavity and three cavity embodiments, a greater bandwidth is obtained compared with prior art combiners where the cavities are tuned to the same frequency. The power loss is slight.

Abstract: A launch tube (2) for launching a missile (4) is supported by a single base (6) which enables the tube (2) to pivot about orthogonal yaw and pitch axes. An aerodynamic stabilizing trim tab (20) is positioned within the interior rear of the launch tube (2). During launch, exhaust gases from the missile (4) flow over the trim tab (20), producing a lift torque which balances the torque about the pitch axis caused by gravity acting upon the missile (4). This gravitational torque would otherwise tend to pull the nose of the launch tube (2) increasingly downward as the missile (4) is launched. The angle of incidence of the trim tab (20), its surface area, and its distance from the pitch axis are varied to adjust the lift torque and the drag attributable to the trim tab (20). The drag is used to balance forward frictional force upon the launch tube (2) caused by the motion of the missile (4). The pitch torques and the linear forces are balanced simultaneously.

Abstract: An electromagnetic cavity filter (10) is formed by at least two cavities (12) having electrically conductive walls (40, 15). When more than two cavities (12) are employed, their midpoints do not have to be colinear; rather, it is sufficient that the angle formed by the midpoints of any three successively coupled cavities is an integral multiple of 90.degree.. Thus, a folded "engine block" geometry can be realized such that the filter's input cavity (12) is proximate to the output cavity (12). This allows a canonic filter response. Each cavity (12) is the equivalent to two filter poles because two orthogonal modes of electromagnetic radiation can resonate therewithin. Electrically nonadjacent modes of proximate cavities (12), as well as electrically adjacent modes, can be coupled, permitting elliptic filter functions. Electrically nonadjacent modes are coupled by means of an iris (30) opening between the two cavities (12).

Abstract: An escapement device has a latch plate interposed between an input and output shaft. The latch plate is pivotably connected to the input and output shafts. The latch plate has a shoulder which abuts a coaxially mounted gear ring. The output shaft is spring loaded to rotate in one direction. The input shaft can be rotated to disengage the shoulder of the latch from one of the gear ring teeth to allow the output shaft to rotate under its spring bias until the output shaft repositions the latch shoulder to reengage another one of the gear ring teeth.