Abstract: A method has been developed for providing tub regions with various resistivities in a dielectrically isolated (DI) structure. The starting substrate material is etched to expose the locations designated for a resistivity modification, and epitaxial material of the modified resistivity value is used to fill the exposed tubs. The remainder of the fabrication process follows conventional DI fabrication techniques. The procedure may simply be used to create a DI structure containing both n-type and p-type tube regions. The idea may also be extended, however, to providing separate tubs with, for example, n+ resistivity, n- resistivity, p- resistivity and p+ resistivity, all within the same DI structure.

Abstract: Integrated circuits implemented in insulated gate (e.g., CMOS) technology have been protected from electrostatic discharge (ESD) by a metal gate field effect transistor. It has been recognized that a "parasitic" bipolar transistor exists in parallel with the metal gate device. Surprisingly, superior protection is obtained by omitting the metal gate, thereby relying only on the avalanche breakdown of the bipolar device for the opposite-polarity protection. It is postulated that the field effect of the metal gate device undesirably restricted the current flow in the prior art technique. The inventive technique may be advantageously implemented using a diode rather than a transistor as the protective element.

Abstract: A closure (20) for optical fiber cables each including at least one optical fiber (38) and a metallic shield (47) enclosed in a jacket (48) includes a splice tray (22), a bonding and gripping assembly (26) and mating cover portions (27, 29). The splice tray includes provisions (24) on one side thereof for holding an optical fiber splice such as one which may be made by a rotary splice and a raceway (51) for routing the optical fiber to the splice. Metallic conductors (45--45), if included in the cables, may be spliced on an opposite side of the splice tray. The bonding and gripping assembly is attached to the splice tray and includes opposed projecting portions (78--78) and ferrules (71--71). Each cable to be spliced is routed to the bonding and gripping assembly to cause each projecting portion to be inserted into a cable end between the shield and core thereof to establish an electrical connection with the shield and to cooperate with the associated ferrule to grip the cable end portion.

Abstract: An optical system, including a waveguide such as an optical fiber, in which optical signals are noninvasively coupled into the waveguide at any point along the length of the waveguide, is disclosed. This is achieved by coupling substantially constant intensity electromagnetic radiation into the waveguide, and then impinging upon the waveguide a directed beam of energy, such as electromagnetic radiation or heat, from an energy source. Alternatively, the waveguide is impinged upon by a combination of an energy beam and a stimulus, e.g., a temperature change. The energy beam, or energy beam and stimulus, induce at least partial absorption of the guided, substantially constant intensity electromagnetic radiation by radiation-absorbing material in the waveguide, to produce the desired optical signal.

Abstract: A switching system including a number of switching modules each having a plurality of access ports. Incoming and outgoing packet channels are extended between each switching module and an inter-module packet switch. Each of the switching modules includes both a packet switching unit and a circuit switching unit for switching information to and from the access ports. Each switching module further includes a control unit that controls the switching units and that generates inter-module control packets, and a communication interface that transmits inter-module control packets generated by the control unit on the incoming packet channel to the inter-module packet switch. The communication interface also transmits inter-module control packets received on the outgoing packet channel from the inter-module packet switch to the control unit.

Abstract: An apparatus and method are disclosed for fabricating an expanded beam cylindrical terminated optical fiber taper from a reduced diameter preform rod. The present invention comprises uniformly heating the circumference of a predetermined portion at an intermediate point of the preform rod to a predetermined temperature and then uniformly pulling the preform rod while continuing to heat additional material of the preform rod to produce a pair of expanded beam cylindrically terminated optical fiber tapers connected by a predetermined length cylindrical central section of standard optical fiber having a uniform diameter less than that of the original preform rod.

Abstract: An I/O interface (24) couples a plurality of I/O devices (29) to a main memory (22) by way of a system bus (23). The I/O interface includes a plurality of buffer blocks (110) permanently associated with one or more memory pages (240). Each page is contiguous within the memory address spectrum and includes a plurality of memory blocks (230). Under control of a sequencer (125), the buffer blocks temporarily store data items being transferred between the memory and the devices. Data items being transferred between any and all devices and a particular memory page are temporarily stored by that page's associated buffer block and no other buffer block. The sequencer accumulates in a buffer block a plurality of data items being transferred by a device to memory by successive write requests, and causes a direct memory access (DMA) conveyance of the buffer contents to the memory upon occurrence of any one of a number of events.

Abstract: A digital clock recovery scheme is disclosed. A reference clock, is used to provide a plurality of N signals with different clock phases. The incoming data stream is sampled and clocked with the reference clock to generate a plurality of M samples for each data bit. The logic values of the M samples are then analyzed to determine the relationship between the current clock phase and the data bit transition. In particular, if all samples agree, the clock phase is correctly aligned with the data. If the clock phase is either leading or lagging the data, various samples will disagree. In the latter situation, the clock phase is adjusted until all samples agree, the particular clock which provides this state thus being defined as the recovered clock signal.

Abstract: Disclosed is a method of fabricating conductive polymer interconnect (CPI) material which employs chains of electrically conductive particles within an elastomeric matrix. Contact resistance is improved by removing a thin layer is elastomeric material which remains after normal processing. The surface layer is removed by plasma etching so that the conductive particles protrude at both surfaces. The protruding particles can be plated to replace any conductive material removed by the etch.

Abstract: Method and apparatus are provided for overcladding a preform rod (22). The preform rod is aligned with and inserted into an overcladding tube (30). The outer diameter of the preform rod and the inner diameter of the tube are such that the clearance between the tube and the rod does not exceed a predetermined value. Successive increments of length of the tube and rod therein are subjected to a controlled zone of heat while the pressure inside the tube is maintained at a value which is substantially less than that outside the tube. This causes the tube to be collapsed onto the preform rod to provide an overclad preform and subsequently a drawn optical fiber in which the overcladding is substantially concentric with respect to the optical fiber core.

Abstract: An arrangement for endpoint detection improves speech recognition accuracy where the input signal includes nonstationary noise. Energy pulses are found by looking for local energy level peaks, then analyzing surrounding energy levels to determine pulse boundaries. Energy pulses are combined according to predetermined criteria to form longer pulses corresponding to words or phrases in the input signal.

Abstract: A digital signal regenerator receives a four-level input signal, amplifies, reshapes, and retimes that signal into a regenerated four-level output signal. A wide range controlled equalizer amplifies and reshapes the four-level input signal into an intermediate signal. A variable all-pass circuit varies the shape of the equalizer's phase characteristic to optimally shape the four-level signal as a function of the maximum amplitude of the four-level input signal. The reshaped four-level signal is retimed and amplified into the regenerated four-level output signal. This enable multiplying the rate at which information is transmitted for a selected pulse rate in the transmission line.

Abstract: Submicron resolution in the fabrication of transistors is obtained by using sidewall techniques. The techniques described remove the sidewalls after oxidizing the materials between the sidewalls and the openings so formed by the removal are used as a mask for subsequent substrate modification by either diffusion or ion implantation.

Abstract: A first one of a plurality of continuous pin strips (24) is selectively fed into an input slot (40) of a machine (38) by first guiding each pin strip into one end (65a) of a separate one of a plurality of spaced channels (64) extending across a plate (46). The plate is selectively indexed by means of a servo-actuator (71) to position the other end (65b) of a first one of the channels containing the first strip in alignment with the input slot on the machine. The first of the pin strips within the first channel is advanced through the first channel and into the input slot.

Abstract: Implantation of a Group V ion species (e.g., phosphorus or arsenic) into an In-based Group III-V compound semiconductor (e.g., InP, InGaAs) followed by implantation of Be ions produces a shallow p-type surface layer and avoids significant in-diffusion of the dopant species. High carrier concentrations and activation efficiencies are attained. The technique has application in the fabrication of FETs, APDs and ohmic contacts.

Abstract: A novel fully differential analog comparator having cascaded gain stages powered by two buses. The two buses are powered by a current source and a variable gain current mirror responsive to the current source. The current source and the current mirror isolate the buses from external power and ground to achieve high power supply noise immunity. True and complementary outputs of the comparator are provided having an adjustable output common mode voltage to optimize the driving of subsequent logic gates responsive to the comparator.

Abstract: During the heating of a moving wire (21) such as when the wire is being aaled, the wire is heated in such a manner that the energy applied to each successive increment of length of the wire is substantially constant. This is accomplished by causing an integral number of half cycles of alternating curent to be applied to each successive increment of length of the wire as the increments are moved from one sheave to another in an annealer (20). In one embodiment, the integral number of half cycles is achieved by adjusting the speed at which the wire is being advanced between two sheaves of the annealer in a manufacturing line. This also may be accomlished by adjusting the distance between the sheaves in an annealing leg of the annealer, or by adjusting the frequency of the applied power source.

Abstract: A flame and smoke resistant optical fiber cable (20) having a relatively small diameter includes a core comprising a ribbon array or a plurality of individual fibers and a sheath system. The sheath system includes an impregnated fiber glass tape (35) which has been wrapped about the core. The tape is impregnated with a solution system which comprises a micaceous constituent, a fluoropolymer constituent and a lubricant such as silicone. The impregnated system provides the tape and hence the cable with unexpectedly superior fire retardant and smoke resistance properties so that the cable is suitable for plenum and riser use. Advantageously, the thickness of the tape impregnated with such a system is relatively thin which is helpful in maintaining a relatively small diameter for the cable. An all dielectric strength member system is disposed between the tape and a plastic jacket (37).

Abstract: A method and apparatus for transmitting messages from one processor to a plurality of other processors in a distributed processing system having no hardware message broadcast facilities. The transmitting processor includes a broadcast program process for controlling the transmission of any messages destined for a plurality of other processors. Different client processes in the transmitting processor request the broadcast process to transmit a broadcast message. The single broadcast process controls the number of individual messages which are sent out sequentially to each of the receiving processors in such a way as to ensure that the broadcast messages do not interfere with other message traffic that frequently has tighter delivery time requirements. The broadcast process transmits the broadcast messages to each of the plurality of recipient processors without waiting for acknowledgment response messages from any of these processors.

Abstract: A fast circuit switching system that establishes a circuit for each packet-sized data communication. Information is conveyed from a number of communications modules in source channels to a number of port controllers and to a network. Information is conveyed from the network to destination channels. Each communications module includes a transmitter that transmits in an associated source channel, circuit setup request signals defining destination channels and also transmits data. Each port controller stores one of a number of status words defining the availability of the destination channels and each of these status words is cycled to each port controller. A port controller responds to one of the circuit setup request signals and to subsequent data, when one of the status words cycled thereto defines as available, a destination channel defined by the circuit setup request signal, by transmitting the circuit setup request signal and the subsequent data to the network.