Abstract: A low cost automatic frequency control system measures short duration radio frequencies with high a degree of accuracy within 0.5 MHz. The system is programmable to allow applicability over a wide range of frequencies within the required accuracy and various signal durations. The system includes circuits to digitize the source signal to a digital pulse train and asynchronously sample the pulse train to obtain a count of the positive edges of the pulses over a sufficient number of samples. A microprocessor computes the statistical average of the count and accurately determines the frequency of the source signal. The system further includes a feedback path to implement correction to the source signal based on the measured frequency.

Abstract: A semiconductor structure is described having a first electrode and a second electrode disposed on a surface of the structure and a bridging conductor connected between the first electrode and the second electrode. The bridging conductor includes a plurality of layers of different metals wherein the plurality of layers of different metals includes a layer of refractory metal adjacent a layer of electrically conductive metal. In a preferred embodiment, the refractory metal is titanium and the electrically conductive metal is gold. With such an arrangement, a semiconductor structure is provided which is effective in preventing restructuring due to mechanical stresses induced in the metal by dissimilar thermal expansion coefficients when electrical pulsing cycles the temperature of the semiconductor structure.

Abstract: A radar system having a radar transmitter and a radar receiver. The radar receiver includes a "local" receiving station and a "remote" located antenna station. A feedthrough nulling system is provided. The nulling system includes a "remote" combiner for providing an feedthrough null residual signal representative of the difference in power between a signal received by the antenna station and a feedthrough nulling signal. A "remote" downlink modulator, disposed at the antenna station, produces an optical signal representative of the feedthrough null residual signal. A "local" downlink optical detector, disposed at either the receiver station or the transmitter, detects the optical signal representative of the feedthrough null residual signal.

Abstract: The present invention provides a rotary joint for optical fibers comprising a plug assembly and a first ferrule having a fiber-entry end mounted coaxially therein, a receptacle assembly and a second ferrule having a fiber-entry end mounted coaxially therein, wherein at least one of the plug-mounted ferrule and the receptacle-mounted ferrule is biased outwardly from a fiber entry-end of the ferrule, and an alignment sleeve for optically connecting the first and second ferrules and maintaining the optical connection during rotation of one of the plug assembly and the receptacle assembly about an axis parallel to a longitudinal direction of the assembly relative to the other of the plug assembly and the receptacle assembly.

Abstract: An antenna for transmitting electromagnetic signals having a frequency less than 500 Hz includes a beam of dielectric material and a conductive sheet wound in a helical pattern around the beam of dielectric material. The antenna further includes a core fabricated from a silicon and iron alloy, the cote disposed between the beam of dielectric material and the conductive sheet. With such an arrangement, a magnetic dipole antenna is provided capable of providing a magnetic moment of approximately 10.sup.6 to 10.sup.7 Am.sup.2.

Abstract: A radar system is provided to track radar energy reflected by a point on the target different from the centroid of a target's radar reflected energy. The radar system includes a target angle/range tracking system and a target energy monitoring/range tracking system. During a first mode of operation, the target angle/range tracking system tracks the centroid of the target's reflected energy; and, the target energy monitoring/range tracking system monitors the strength of energy reflected from points, or regions along the body of the target different from the centroid reflected energy producing region. When the signal strength to noise ratio (i.e., S/N ratio) from a reflection at one of the monitored points along the target exceeds a predetermined level indicating detection of a secondary reflector along the body of the target, a second operation mode commences.

Abstract: A method of guiding missiles in the terminal phase of an intercept. An image of the target area is stored as a reference. The reference is expanded by an amount which increases as the missile approaches the target. The expanded reference is then correlated to successively formed images of the target and the results of the correlation are used to guide the missile. The amount of expansion of the reference is selected to compensate for growth of the image as the missile approaches the target. A filter used to filter the successively formed images is adjusted to correspond to the amount of expansion in the reference.

Abstract: A system for obtaining digitized samples of an analog signal at a selectable rate, R. The system includes: a timing generator for producing a train of sampling pulses at a predetermined sampling rate, f.sub.s ; an analog to digital converter for producing a digitized sample of the analog signal in response to each one of the sampling pulses; a processor; and, a selector, for passing each Nth one of the digitized samples produced by the analog to digital converter, where N=f.sub.s /R to the processor. The selector includes a decimator, responsive to a signal, N=f.sub.s /R, representative of the ratio of the sampling rate, f.sub.s, to the digitized signal obtaining rate, R, for producing pulses at the rate, R=f.sub.s /N; and, a register for storing each Nth one of the digitized samples produced by the analog to digital converter, each one of such digitized samples being stored in response to a corresponding one of the pulses produced by the decimator.

Abstract: A radar system having a transmitter for transmitting a series of radio frequency (RF) pulses with sequential, incrementally changing carrier frequencies. A receiver receives energy from multiple scattering points of an object reflecting such transmitted RF pulses. The received energy from each one of such scattering points includes a series of radio frequency (RF) pulses corresponding to the transmitted pulses delayed in time, .tau., from the transmitted pulses an amount proportional to the range to such scattering point and shifted in frequency from the carrier frequency an amount proportional to the velocity of such scattering point. The receiver includes a heterodyning section, responsive to a range tracking error signal, .epsilon..sub.R, and a velocity tracking error signal, .DELTA..sub.VEL, for producing a series of pulsed signals for each one of the scattering points. Each one of the pulsed signals for any given scatterer sequentially changes in phase, .phi., at a rate, .DELTA..phi./.DELTA.

Abstract: A chip carrier structure for containing a chip carrier having electrical contact pads having a positioning structure for the chip carrier and a slotted structure mated to form a mated structure containing said chip carrier, the slots of the slotted structure being in alignment with the pads of the chip carrier to provide electrical and mechanical access to the pads from the exterior to the interior of the mated positioning and slotted structures.

Abstract: A pair of crystallographically matched piezoelectric substrates are sealed together to provide a package for a SAW device. A sealant material including a glass frit is deposited on a selected portion of a first one of the pair of substrates. The substrate having the sealant material is then heated to a temperature which is substantially below the glazing temperature of the sealant material to dry the sealant material. The substrate having the dried sealant material is heated a second time at a temperature just above the softening temperature of the glass frit to glaze the glass frit component with other components of the sealant material being driven from the glass frit during the heating cycles. The substrate having the glazed frit and the other remaining substrate are then mated together in a predetermined manner.

Abstract: A phased array radar antenna uses time-steering subarray notch weightings to produce a wideband notch in the direction of interference for Electronic-Counter-Measure (ECM) interference suppression. A predetermined set of subarray notch weightings, each set being identical for each subarray, is stored in controllers each of which is coupled to a plurality of phase shifters and attenuators for feeding radiating elements of the antenna. Interference suppressors operate from a plurality of controllers to produce a subarray pattern having a notch in the direction of interference. Beamformers then combine outputs of all time-steering subarrays in the antenna so as to produce an antenna pattern having a wideband notch in the direction of interference.

Abstract: A transmit/receive module including digitally controlled analog circuits is described. The digital circuits use a logic family adapted for use with analog monolithic integrated circuits. The disclosure also describes a preferred process to provide digital and analog microwave circuits on a common semiconductor substrate.

Abstract: Spurious frequencies are suppressed in a transmitter by an RF pulse fall time controller circuit comprising a quadrature hybrid matched attenuator located between a predriver and the first stage of class "C" driver amplifiers. The circuit linearly attenuates RF pulses and slows pulse fall time. Operation of the circuit is initiated when the rising edge of a pretrigger starts a pretrigger generator which then triggers the application of current bias to the attenuator circuit. After a controlled period of time, the circuit decreases the forward current bias of PIN diodes in the attenuator thereby increasing the diodes' series resistance and increasing the attenuation of the RF pulses. This creates a slow pulse fall time thereby suppressing spurious emissions caused by parasitic ringing of the cascaded Class C common base transistor amplifiers in the transmitter.

Abstract: A piezoelectric fluid control valve (10) and fluid control method using a polymorph (48) with a characteristic that as a potential difference is applied thereto, the polymorph is deflected. The valve includes a supply port (14) for introducing fluid and a chamber (16) defined within the valve body. An outlet port (18) is in fluid communication with the chamber and a device controlled thereby, such as an anti-lock brake system. A relief port (78) returns fluid to a source thereof. Upper and lower metering elements (100, 116) are supported within the chamber. A cantilevered spring valve (128, 130) is positionable within metering orifices defined within the metering elements (100, 110). The polymorph is positioned between and in operative communication therewith. An electrical circuit (56) is connected to the polymorph, the circuit providing the potential difference thereto, which is regulated in accordance with an input signal delivered to the circuit.

Abstract: A transceiver integrated circuit including a transmitter section having a phase-locked loop with an oscillator to provide an output at a predetermined transmission frequency, and a receiver section having a phase-locked loop with an oscillator used to provide a recovered clock from an incoming data signal. In a second mode when no incoming data is being received, the receiver oscillator is controlled in accordance with the transmitter oscillator to operate the receiver oscillator at the expected frequency of future data. Therefore, when data is received, the receiver oscillator is at the same approximate frequency as the incoming data thereby enabling fast acquisition by merely adjusting the phase of the receiver oscillator to the incoming data.

Abstract: A content limit addressable memory (CLAM) having a plurality of lower and upper limits stored therein for comparison to corresponding subfields of an input word. Each corresponding upper and lower limit forms a bracket. Corresponding brackets form a window. The brackets correspond to the subfields and are of the same number of bits. The brackets and subfields are alterable in width to allow each bracket and subfield to have any number of bits in multiples of two. A valid match of the input word with any window can occur with any combination of the brackets of a window matching or not matching the corresponding subfields of the input word. A plurality of outputs corresponding to each of the windows indicates a match of the corresponding window to the input word. Additionally, the CLAM can compare data stored therein against an applied window with the matching operations as described above.

Abstract: A composition of ferrite and epoxy having the form of a film which can be cut, pressed onto word straps, and heat-cured to form an encapsulating keeper on a plated wire memory. The film comprises ferrite powder in a mixture of epoxy resins, typically Epon 1009 and Epon 828, pulverized dicyandiamide and butadiene/acrylonitrile rubber. The mixture is sprayed onto a sheet of halogenated polyolefin and air dried for 8-12 hours at between 160.degree. F. and 180.degree. F. The resulting flexible film is die cut to fit over word straps and further processed by applying 50-75 psi at 325.degree. F. for one hour.

Abstract: A field emission display having a plurality of pixels is disclosed wherein each pixel includes a cathode with a plurality of field emitters and corresponding gate electrodes to emit electrons, an anode distally disposed with respect to the cathode, the anode and the cathode capable of having a voltage difference greater than 6000 volts, and a focus grid disposed between the anode and the cathode, the focus grid having an aperture and disposed in proximity with the cathode to focus electrons from the plurality of field emitters of the cathode toward the anode. With such an arrangement, a field emission display is provided having greater brightness and efficiency.

Abstract: Charge coupled shift registers for sonar beamforming provide many channels of high resolution large delays by the cascading of two registers. Two equivalent embodiments are disclosed. In one embodiment the shift rate of the input shift register is an integer multiple "m" of the shift rate of the output shift register which is responsive to every m th signal presented to it. The other embodiment samples the signal in the input register by selected m th pulses of a pulse train whose frequency is m times the shift frequency of the output register. Each embodiment preserves the higher resolution phase information and incremental delay of the higher frequency sampling of the input shift register. The long time delay is provided by the output shift register operating at the lower shift rate.