Abstract: Simultaneous FFT's are calculated for two real input sequences utilizing a two channel recursive FFT structure. The method of operating such a structure disclosed includes the log.sub.2 N stages (for an N-point transform) known in the prior art plus a final unscrambling stage. A method of arranging the outputs of the log.sub.2 N-th stage for use as inputs to the unscrambling stage is disclosed which results in substantially unscrambled FFT outputs for the two sequences without the need for extra unscrambling hardware.

Abstract: A servomotor controller provides high speed servomotor positioning be means of an on line adaptive state-feedback control algorithm. Servomotor position and velocity are the feedback states and each has an associated gain selected by means of a servomotor characterization scheme. The mechanical break frequency is used to select optimum gains and a high speed estimation technique is used to determine the mechanical break frequency. Position step change may also be used to select optimum gains. Gain tables are produced by an off-line simulation technique.

Abstract: A method of manufacturing optically sensitive semiconductor devices in which an anti-reflective coating is provided without the addition of mask or etch steps to the manufacturing process flow. A single layer of silicon nitride is patterned to provide an anti-reflective coating over the active area of the optically sensitive device and to form the dielectric of any capacitors also a part of the integrated circuit. An oxide passivation layer is used so that it may be opened over the active area without disturbing the anti-reflective coating.

Abstract: An automated integrated circuit tester is constructed as a state machine. Complete test routines are contained in a state memory. A state generator is controlled by state memory and produces addresses therefor. A complete test condition can be set up using the information in a single address in state memory. Provisions are made for test routine loading from a local computer, which also serves to log data without interfering in test execution. A preferred embodiment provides both DC parametric and AC testing in a tester which can accomodate up to 256 pins. A single force and measure unit is devoted to each pin.

Abstract: Maskless etching of polysilicon is accomplished by exposing portions of a polysilicon surface to ion bombardment. Bombardment by oxygen or hydrogen ions is effective to reduce the etch rate of polysilicon in a chlorine-containing plasma. Therefore, patterned ion bombardment prior to etching in a chlorine plasma is effective to pattern the polysilicon surface.

Abstract: Laser marking of metal surfaces, particularly semiconductor device packages, is accomplished by depositing an electroless nickel layer on the surface, converting the nickel surface to a form in which it is highly absorptive of radiant energy and exposing the converted nickel surface to laser energy through a mask. The resulting mark is highly resistant to abrasion and corrosion. In addition, the method is highly suitable for use with automated laser marking equipment. Furthermore, it appears that the presence of the converted electroless nickel surface in the region of welds increases the hermeticity of the welds. This is particularly useful in packages of the TO-3 type and similar types.

Abstract: Radiation hard, N-channel MOS devices comprising active regions surrounded by field oxide protected by an underlying region of heavily doped p-type material. The guard region is doped heavily enough to provide field inversion voltages in the range of 50 V to 60 V prior to irradiation. The guard region is separated from the source and drain regions to provide acceptably high breakdown voltages. The devices are produced with minor variations to well known, high density local oxidation of silicon-type processes.

Abstract: A hardware simulator for simulating digital structures includes a general purpose computer and an improved simulator processor. The improved processor handles an advanced primitive having four inputs and one output and which is capable of representing a memory cell or similar structure. The architecture of the processor provides highly efficient compilation of the input states of a primitive and the primitive evaluator and resolver logic provide the output state in a minimum number of clock cycles. The simulator is a single, low cost unit capable of simulating 64K cell structures with a speed comparable to prior art simulators.

Abstract: A split gate, leading edge range tracking apparatus for use in coherent radar seekers is substantially balanced in noise. The early and late gate widths and channel gains are chosen to provide leading edge tracking while avoiding range drift during target fade. A relationship is derived whereby the ratio of the early and late gate widths equals the square root of the ratio of the late and early gate channel gains.

Abstract: Electronic packages and the like, particularly finished packages with leaky welds, are hermetically sealed by vapor deposition of a polymer film through a sealable port. A high quality film is obtained by slow deposition of a monomer vapor which subsequently polymerizes. The process is not destructive due to the lack of high temperatures and curing agents. Extremely low permeability for common molecules and for water vapor is achieved by utilizing C-type para-xylylene as the polymer material.

Abstract: A plasma reactor of the single wafer, planar electrode type achieves improved serviceability by means of a service seal arrangement. The lower electrode of the plasma reactor is carried on a chuck. Both the chuck and the upper portions of the reactor seal to an upper plate of a vacuum containment vessel. A wafer transport mechanism is contained within the vacuum containment vessel. The sealing arrangement allows removal of the upper portions of the reactor and even replacement of the lower electrode without disturbing the vacuum in the vacuum containment vessel.

Abstract: A constant false alarm rate (CFAR) apparatus is responsive to detected transitions in the clutter signal level to remove certain range cells from the alarm threshold calculation process, whereby the CFAR detector retains maximum sensitivity in the vicinity of clutter transitions while avoiding increased false alarm rates. A transition detection apparatus searches for transitions in range cells preceding the threshold calculation window and controls switches which remove range cells from the threshold calculation as the transition is shifted into and through the threshold calculation window.

Abstract: A plasma reactor system is described in which a plurality of components are segregated into modules. Devices known as mass flow controllers for gas supply lines are located one each per module. A plenum for inert gas is connected to each module to bath the module in an inert atmosphere.

Abstract: A low SNR symbol synchronizer utilizes two quadrature channels and a delay and multiply technique to produce four product signals. Two of the product signals are same-channel products and two are cross-channel products. When combined and applied to a synchronizing apparatus such as a Costas loop, the signals provide improved performance at low SNR and avoid the need to know the carrier frequency when setting the delay.

Abstract: A method of coupling electronic devices into electrical circuits, particularly hybrid circuits and the like, by utilizing a pre-formed lead frame. The lead frame is formed from a gold film or the like and provides smooth width variations between the signal carrying lines of the circuit and the terminal portions of the device. Wobble bonding and wire bonding processes are adapted for use in practicing the invention. High frequency and/or wide band circuits are significantly improved by use of the present invention as opposed to prior art wire bonding techniques.

Abstract: A low RCS RF switch fabricated in microstrip utilizes bridge conductors carried on a second substrate to perform the coupling and uncoupling function. The second substrate is moveably affixed to the first substrate on which the primary RF transmission line is carried by means of a hinge spring. The switch is actuated by means by a pneumatic bladder coupled to a pneumatic control line. A three bit phase shifter utilizing such a switch is disclosed which is suitable for use in certain phased array antennas.

Abstract: An apparatus and method for accurately locating the edges of RF pulses is suitable for use in position determining receivers and the like. Matched detector channels, one of which is attenuated for use as a threshold, are compared after one has been delayed to produce a comparator transition coincident with either the leading, the trailing, or both edges of the input RF pulses.

Abstract: Compound surface acoustic wave matched filters comprise chirp-biphase and biphase code multiplex transducer pairs on piezoelectric substrates. Both alternatives offer significantly improved processing gain when compared with conventional biphase filters. The advantage is realized by convolving the correlation peak of the chirp or biphase input transducer on the response of the conventional biphase output transducer, thus achieving a large processing gain with a minimum number of transducer electrodes.

Abstract: A branch metric processor for use in a maximum-likelihood convolutional decoder accepts a set of soft-decision symbols, an indicator of a level of quantization thereof and a set of erase control signals and generates branch metrics for base code rates of 1/3 and 1/2. The apparatus represents a substantial reduction in complexity over prior art devices. Erasure of selected symbols allows the processor to generate branch metrics for higher code rates and is advantageous in very low code rate applications.

Abstract: An image spatial filter comprises back-to-back image cavities with means for coupling energy from one cavity to the other. Large angle of incidence energy is attenuated by each image cavity successively, thus providing a high degree of attenuation. Two quarter wavelength dielectric sheets with a ground plane between them and spaced from each by one-half wavelength form the image cavities. Slots in the ground plane provide coupling from one cavity to the other. Image spatial filters are not substantially more expensive than multi-layer dielectric spatial filters and are as easily fitted to existing antennas. But image spatial filters substantially reduce large angle passbands caused by the Brewster effect and by cavity resonance in dielectric spatial filters.