Abstract: In the preferred embodiment, a monocrystalline film of substituted yttrium iron garnet (YIG) deposited on a <11> oriented gadolinium gallium garnet (GGG) substrate is formulated so that the temperature variation of the ferromagnetic resonance frequency of the film has an ordinary minimum. For a range of temperature variations about the temperature at which the minimum occurs, therefore, the resonance frequency of the film is relatively insensitive to variations in temperature. This minimum is believed to occur where the temperature variations of the demagnetizing effect and the temperature variations of anisotropy effects more or less counterbalance each other. The counter-balancing effects are brought within range of each other primarily by the substitution of gallium or aluminum for iron and substitution of lanthanum for yttrium in the substituted YIG. Gallium or aluminum reduces the temperature drift of the saturation magnetization. Lanthanum adjusts the misfit stress and thus the anisotropy effects.

Abstract: A throttle servo for each engine of a multiengine aircraft and servo tracking means for detecting and compensating for servo drift during autothrottle mode of operation.

Abstract: In this monolithic detector array, a signal processing layer is epitaxially formed directly on an active detector layer. The active detector layer is supported by a transparent substrate. The three layers are made of intrinsic semiconductors of the same conductivity type (e.g., n-type). The semiconductor forming the active layer has a smaller bandgap than the signal processing and substrate layers. A plurality of vias of opposite conductivity type (e.g, p-type) extend through the signal processing layer into the active detector layer where they form p-n junctions with the active detector layer. These p-n junctions collect charges generated by the radiation and the vias conduct these charges to the signal processing layer where gates, AC background suppression circuitry, and a charge coupled device process the photogenerated signals.

Abstract: A single sideband signal can be demodulated by using sampled data techniques. An intermediate frequency (IF) radio signal is split into two branches and is sampled by two sample and hold devices; each sample and hold device operates at a rate that is not only a submultiple of the carrier frequency, but is also at least twice the information bandwidth. Prior to, or during sampling of one branch (the quadrature branch), a Hilbert's transform is performed upon the IF signal which results in the output of the two sample and hold devices being in phase quadrature. A phase shift of 90.degree., using a baseband finite impulse response Hilbert's transform filter, is performed upon the output signal of the quadrature branch's sample and hold device. The sum of the inphase sampled signal and the filtered quadrature phase sampled signal produces the demodulated lower sideband while the difference between the two produces the demodulated upper sideband.

Abstract: The present invention uses two interconnected baluns with the balanced output of one feeding a balanced input of the other. When this filter is used in conjunction with a signal frequency converter, the balun pair not only provides extremely effective bandpass filtering so as to pass the RF frequencies and not the IF frequencies but, in addition, provides a condition which appears to the IF as a nearly open circuit and thus provides a large amount of reflection or return of the IF signals to the signal converter. Through the use of additional grounding stubs, additional coupling means, increased separation between coupling means and separated ground planes each singularly or in combination, improved performance has been obtained as compared to the prior art.

Abstract: A method and apparatus are provided for automatically controling the strain rate during superplastic forming of a blank of material into a part. The method and apparatus produce a part in a minimum time by deforming the material in its optimum superplastic conditions. A relationship is determined between time and the pressure required to form the blank against the configured surface of a die at a strain rate which causes the blank to flow superplastically. The blank is positioned in the die and held at a temperature at which the material exhibits superplasticity. Pressure is automatically applied across the thickness of the blank in accordance with the previously determined relationship between time and pressure until the part is formed. The apparatus comprises conduits connected to a die and to a high pressure gas. Valves in the conduits regulate the pressure applied to the blank. A controller receives command signals from a programmer which is programmed with the desired time vs pressure relationship.

Abstract: An electromagnetic transducer is provided which transmits and receives ultrasonic waves from a metallic part predominately in only one direction. At least two rows of permanent magnets are placed adjacent each other in a side-by-side relation. The N-S axes of the magnets are substantially parallel and adjacent magnets in each row have opposite polarity so that two periodic magnetic fields are created. The adjacent magnets are off-set by one-fourth period. Coils wrapped around each row of magnets are driven in phase quadrature in order to generate a unidirectional elastic wave in the metallic part. In another embodiment, sets of three rows of magnets are offset by one-sixth period and driven in 60.degree. phase shift.

Abstract: An "on chip" substrate bias generator circuit to automatically compensate for threshold variations of devices that form a MOS circuit. The substrate bias generator includes a voltage doubler (or trippler) to develop a wide range of negative bias voltage to be fed back via the substrate to the MOS circuit to provide uniform bias control of the circuit devices.

Abstract: An R-F coupling device of greatly improved coupling and shielding characteristics is disclosed for inductive connection to the antenna circuitry of a hand-held transceiver without necessitating the removal of the transceiver antenna.

Abstract: A receiver includes demodulator, squelch gating and squelch circuit for controlling the gating. A blanking circuit, responsive to impulse type noise, prevents impulse noise energy from contributing to the control of the gating.

Abstract: The present invention relates to the method of and apparatus for performing test operations on a primary counter to make sure that it is continually providing correct operational capability. The tests comprise periodically interrupting the operation of the primary counter, forcing it to count to both the maximum and minimum limits and checking to make sure that the limit has been obtained, inserting an intermediate number and checking to be sure that this number can be transferred therethrough and then resetting the primary counter to the count of a backup counter which has been keeping count during the test process. Finally, a comparison is continually provided during normal operation between the backup and the primary counter to make sure that they are tracking with the same counts. Failure of any of the comparisons or tests to be completed in accordance with specified results causes an error signal to be generated as an alarm.

Abstract: M-type hexagonal ferrites whose prototype chemical formula (BaFe.sub.12 O.sub.19) contains no zinc and W-type hexagonal ferrites whose prototype chemical formula is (BaZn.sub.2 Fe.sub.16 O.sub.27) can be successfully grown by LPE on spinel substrates having appropriate lattice parameters when controlled quantities of the zinc are present in the melts from which these hexagonal ferrites are grown. Using this growth technique, composites comprising a monocrystalline magnetic M-type or W-type hexagonal ferrite film on a non-magnetic single crystalline spinel substrate are provided.

Abstract: An autonomous navigational system for an airborne vehicle is disclosed which automatically updates its position and heading coordinates at each of a plurality of checkpoints along a preselected flight path. Prestored in a memory of the navigational system is a plurality of reference map images respectively associated with the plurality of checkpoints. Each reference map image is comprised of a plurality of terrain features associated with the terrain about an associated checkpoint. In operation, an acquisition unit senses an image of local terrain at each checkpoint. The relative sizes of reference and sensed map images vary with the mission requirements. A terrain feature extractor detects a plurality of terrain features contained in the sensed map image.

Abstract: A free-running inverter preventing excessive current spikes comprises a transformer and a switch means for alternately connecting, and then disconnecting, a DC voltage to a transformer primary winding which encloses a parallel combination of a saturating magnetic core and a non-saturating magnetic core. A transformer feedback winding enclosing only the saturating core drives the switch means during and between switch states. Switching between states is accomplished prior to saturation of the composite core.

Abstract: A receiving system is described which has the capability of substantially cancelling broadband noise, such as impulse noise, atmospheric noise, electrical line noise and receiver front end noise, from a selected radio frequency passband. In a first embodiment, a desired radio frequency passband is selected and converted to a broadband intermediate frequency (IF) signal, which is applied in parallel to the inputs of first and second frequency channels. When broadband noise is present in the broadband IF signal, the first frequency channel develops a desired audio signal in the presence of an undesired first broadband noise signal, while the second frequency channel develops an undesired second broadband noise signal which is correlated with the first broadband noise signal. An adaptive transversal filter is responsive to the second broadband noise signal and to an output signal for adaptively developing an estimate of the first broadband noise.

Abstract: An arc-scanned sector cathode ray tube display system achieves constant writing speed by developing trigonometric X and Y deflection signals with amplitude linearly decreasing and scan rate linearly increasing as arcs are drawn from periphery toward apex of the display sector. Video/deflection synchronism is achieved by development of a video clock pulse train comprised of selected pulses from a clock source by means of which displayed video bits are shifted from rho-theta formated storage on a time/position basis such that video and beam position are synchronized to within one displayed picture element throughout the sector display.

Abstract: An improved scheme for selectively addressing a matrix arrangement comprised of ferroelectrics having x and y orthogonally disposed intersecting lines. A one-third selection scheme is utilized that includes normalized selection signals having amplitudes: V.sub.x =0; V.sub.x =2/3; V.sub.y =1/3; and V.sub.y =1, which signals can be applied to the intersection of an x and y-line. The instant selection scheme minimizes both hysteresis creep and the cross-coupling voltage between x and y-lines to prevent undesirable hysteresis switching of the ferroelectric matrix arrangement.

Abstract: In a binary phase-coded pulse compression type pulsed energy system, means for synchronously transmitting two separately binary coded signals, the code for each signal having an autocorrelation function exhibiting a maximum synchronously occurring with that of the other coded signal, the two autocorrelation functions, when combined, being mutually cancelling except at the synchronous occurrence of the maxima of the autocorrelation functions.

Abstract: The method of and apparatus for synchronizing all local oscillators in a multinode communication system is disclosed wherein each local oscillator is synchronized to the average frequency of some or all incoming signals from neighboring nodes. This is accomplished by detecting the difference in frequency between the local oscillator and the frequency of incoming signals, averaging these differences, and using the average to adjust the local oscillator. The frequency difference is measured over a period of time and the accumulated difference over the period is checked for reasonableness prior to use. Its use is further delayed after the period of measurement by a period of time while the incoming link is monitored for signal problems which might have occurred toward the end of the accumulation period and which therefore would not have been detected by an immediate reasonableness check.

Abstract: When a pulse-width series modulator is connected to the cathode of an RF radio transmitter tube for the purpose of series modulation, filtration of the PWM switching signal is required to eliminate the switching signal from the output modulating signal. Stray capacitive effects in this filtration generate undesirable distortion in the trailing edge of the signal appearing in the last stage of the PWM thereby producing non-linearity in the modulation of the RF output tube. The present disclosure illustrates circuitry for complimentarily modifying the leading edge of the pulses so as to maintain a linear relationship in the time integral of voltage in the output signal. This modification is accomplished through a plurality of capacitive units each having different time constants for charging and discharging.