Abstract: A method is provided for forming a bolometer having an infrared sensitive material disposed on a platform elevated over a surface of a semiconductor body. The method includes forming a thermally insulating support layer to provide the platform and legs for supporting the platform over the semiconductor body. A layer of electrically conductive material is formed over the support layer and onto electrical contacts of an electronic circuit formed in the semiconductor body. The layer of electrically conductive material is patterned into electrical conductors passing, at a proximal end thereof, from the contact region of the electronic circuit upwardly to, at the distal end thereof, the platform region. The patterned electrically conductive layer is used as a mask for selectively removing portions of the support layer exposed by the patterned electrically conductive layer while portions of the support layer remain disposed under such patterned electrically layer.

Abstract: A photovoltaic (PV) power system having distributed square wave current DC to AC inverters integral with strings of PV cells in a PV array. The PV array is arranged into four quadrants and phase-shifted and summed AC voltages from each quadrant are further summed in a 12-phase to 3-phase transformer to produce a sinusoidal 3-phase AC voltage with a total harmonic distortion of less than 5 percent.

Abstract: An antenna having: a beam forming network; an array of antenna elements; and a parallel plate region coupling the array of antenna elements and the beam forming network formed on a common, folded dielectric substrate. The beam forming network includes strip conductor circuitry separated from a ground plane conductor by a portion of the substrate. The array of antenna elements comprising strip conductor circuitry separate from a ground plane conductor by a second portion of the substrate. The parallel plate region is disposed about a folded region of the substrate and includes a pair of conductive plates separated by the folded region of the substrate. With such arrangement, a compact antenna is provided using the folded substrate. Also, spurious radiation (which has been found to radiate when strip conductor circuitry is disposed about the folded region to couple the array of antenna elements and the beam forming network) is confined by the parallel plate region.

Abstract: A laser having a gain medium disposed in a resonant cavity having a pair of end reflectors. One of such reflectors has a reflectivity lower than the reflectivity of the other one of the reflectors. The reflectors are arranged to provide a single ended output for the cavity through the one of the reflectors having the lower reflectivity. A saturable absorber is formed on the one of the reflectors having the lower reflectivity. With such an arrangement, fabrication of the saturable absorber on the single ended output coupler is greatly simplified. The gain medium is a doped fiber and the saturable absorber formed on the one of the reflectors having the lower reflectivity is affixed to an end of the doped fiber gain medium. With such an arrangement, a highly efficient, relatively low cost, mode locked laser is provided.

Abstract: A video comb filter for PAL or NTSC TV standards separates luminance and chrominance signals from a composite video signal by adaptively selecting between at least two different filtering processes, depending on whether the chroma output of the processes is "legal" (is within certain limits) in terms of both magnitude and phase. The present comb filter has a two horizontal scan line delay, and is such that the magnitude and phase of a chrominance signal output from the filter never exceeds that of a single band pass filtered version of the composite video and subsequently does not invert the phase of the luminance signal. The chrominance output signal characteristic is similar to that a four scan line filter; however, because the present filter only uses two lines of delay, any vertical cross luminance occurs across only two scan lines and the diagonal luminance resolution is significantly improved. The output of the comb filter is "legal" (within the RGB color cube) at all times.

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 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: 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: 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 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.