Abstract: A code-excited linear-predictive (CELP) coder for speech or audio transmission at compressed (e.g., 16 kb/s) data rates is adapted for low-delay (e.g., less than five ms. per vector) coding by performing spectral analysis of at least a portion of a previous frame of simulated decoded speech to determine a synthesis filter of a much higher order than conventionally used for decoding synthesis and then transmitting only the index for the vector which produces the lowest internal error signal. Modified perceptual weighting parameters and a novel use of postfiltering greatly improve tandeming of a number of encodings and decodings while retaining high quality reproduction.

Abstract: A phase-shifting lithographic mask is fabricated, in one embodiment, by using a resist layer that is negative tone with respect to a (patterned) electron beam and is positive tone with respect to a (flood) mid-ultraviolet beam, with the tone of the electron beam predominating over that of the mid-ultraviolet beam. The resist layer is spun on a body comprising a patterned metallic layer located on a (transparent) quartz slab. The body is subjected from below to a flood mid-ultraviolet beam and from above to a patterned electron beam whose edges are located somewhere in the midst of the patterned opaque layer but are not coincident with any edges of the patterned opaque layer. Thus, a subsequent development of the resist layer removes those regions and only those regions of the resist layer upon which the ultraviolet beam was incident--i.e., not in the shadows cast by the patterned opaque layer--in the absence of incidence of the patterned electron beam.

Abstract: Previous efforts to measure polarization dependent loss of optical components have been limited in uncertainty to more than 0.01 dB. This is because the power meter used in a test set contains polarization dependent loss which adversely affects the final readings. It is here disclosed that an unpumped erbium doped fiber can convert a received polarized signal into unpolarized amplified spontaneous emission of a longer wavelength if the fiber is of sufficient length to absorb the received signal. By locating the inventive unpumped erbium doped fiber upstream of the power meter of a test set, the polarized signal to the power meter is coverted to an unpolarized signal and, therefore, the polarization dependent loss of the power meter can not influence the measurement obtained.

Abstract: Capacitive proximity sensors are disclosed that can be fabricated in different shapes, sizes and materials used in a wide variety of applications. Each such sensor includes a sensing electrode and a guard electrode. The sensor electrode and guard electrode can be parallel conductors separated by an insulating layer, such as a double-sided circuit board shaped to suit the application. One such sensor is transparent for use in conjunction with an optical bar-code scanner. Another sensor is annular in shape for use in conjunction with a telephone transmitter. The sensing electrode and the guard electrode are driven in unison by an RF signal. The proximity of an object to the sensor is observed by detecting changes in the RF current flowing through the sensing electrode caused by the proximity of an object to the sensing electrode.

Abstract: Broadband in-line gratings in optical waveguides are disclosed. The gratings have a bandwidth of at least 2 nm (preferably at least 4 nm) and a peak reflectivity of at least 70% (preferably at least 90%). Exemplarily, such gratings can be formed in H.sub.2 -treated Si-based fibers that support a normalized index change of at least 10.sup.-3. Gratings according to the invention can be used, for instance, to form pump radiation reflectors in an optical fiber communication system with Er-doped fiber amplifiers, or to flatten the amplifier gain curve. The gratings can be of the blazed or non-blazed type.

Abstract: An optical cable portion (10), resident within a cable closure (14), is caused to receive a water blocking arrangement which is effective to prevent water, which enters an internal cable portion (24) through an unintended cut (21) in an outer jacket (18) of a cable portion (20), from entering an interior of the cable closure. A plurality of water blocking materials (30 and 32) are coaxially disposed about the outer jacket and a core tube (26) of the cable portion, respectively, and cooperate with a heat shrinkable plastic tube (34) which substantially covers the water blocking materials to prevent the movement of water from the internal cable portion past the water blocking materials.

Abstract: Phototools are located for processing both sides of printed circuit board panels by an apparatus and process that utilizes a work station with two alignment fixtures each including panel center registration PCR alignment mechanism to locate phototools and panels. Processing steps utilize the alignment fixtures to locate phototools on both sides of a panel. Each of the two phototools is initially positioned on its alignment fixture by the PCR alignment mechanism and secured to its alignment fixture by means of a vacuum supplied by a vacuum chuck which is operative as the top surface of the alignment fixture. The panel is then placed on top of the first phototool and aligned to the first phototool in the first alignment fixture using the PCR alignment mechanism. This first phototool is then affixed to the first side of the panel.

Abstract: In a wafer fabrication process in which a photoresist stripper must be removed from the surface of a semiconductor wafer, the photoresist stripper is rinsed by inserting the wafer in a vessel (23, FIG. 3) filled with water and simultaneously pumping carbon dioxide and water into the vessel to cause the water to overflow the vessel. Preferably, the wafer is contained within the vessel for at least five minutes, and, during the rinsing step, the water completely fills the vessel and overflows at a rate of at least fifty percent of the volume of the vessel each minute. We have found that this method of rinsing photoresist stripper from semiconductor wafers significantly reduces or eliminates the incidence of corrosion pitting on aluminum conductors (12, FIG. 1) of the wafer (11).

Abstract: A method for interconnecting first and second optical fiber bundles (FIG. 4 ), each bundle comprising a plurality of optical fibers, comprises the steps of accurately forming substantially identical matrix arrays of apertures in first and second thin securing plates (FIG. 1, 20, 17). The use of thin plates for the securing plate makes it possible to form apertures by masking and etching with great precision, but the plates themselves have little mechanical strength. The first and second plates are aligned (by balls 24), and a first support member (31), which is mechanically rugged, is simultaneously contacted to the first securing plate (17) and to a first alignment pin (27). The first support member (31) is bonded to the first securing plate while the first securing plate (17) is in alignment with the second securing plate (20).

Abstract: A gas tube protector includes a new coating for the electrodes. The coating, which eliminates the need for conditioning the electrodes prior to using or testing the protector, includes barium titanate and titanium.

Abstract: Data samples describing a plurality of micro-segments that compose a symbol to be recognized are received from a device such as an electronic pad. Preprocessors map the micro-segments into cells of a plurality of feature arrays with different resolutions. Preprocessors assign values to the cells based on the length of a micro-segment associated with the cell, and how well the features of the associated micro-segment correspond to the feature label of the cell. The cell values are used as inputs to comparators that compare the feature arrays with reference arrays. The results of comparisons involving lower resolution feature arrays and reference arrays, are used to limit the number of comparisons involving higher resolution feature arrays and reference arrays. The highest resolution comparison selects the reference array that identifies the symbol to be recognized.

Abstract: Improved jitter performance is realized in a desynchronizer for obtaining an asynchronous digital signal, e.g., a DS3 signal, from a received synchronous digital signal, e.g., a SONET STS-1 signal. The improved jitter performance results from the use of a unique dynamic bit leaking arrangement in conjunction with a digital phase locked loop and desynchronizing elastic store. An optimum bit leak interval is obtained by controllably leaking a greater number of shorter interval STS-1 bits than the number of received pointer adjustment bits or, alternatively, leaking a fewer number of longer interval bits than the net number of received pointer adjustment bits. Additionally, the affect of random pointer adjustments and the superposition of randomly received pointer adjustments on a periodic sequence of received pointer adjustments is minimized by employing a "static" queue of pointer adjustment bits to be leaked.

Abstract: An integrated circuit for detecting harmonic lock of a phase-locked loop includes a frequency synthesizer for receiving a reference clock signal and for generating an oscillator clock signal. A phase generator receives the oscillator clock signal and generates a phase of the oscillator clock signal. A shift register receives as an input the reference clock signal and is clocked by the phase of the oscillator clock signal to produce an output that is a repetitive sequence of logic states. In an alternate embodiment, a harmonic decode circuit decodes the shift register output to determine which harmonic the phase-locked loop has locked onto.

Abstract: An optical packaging arrangement is disclosed which utilizes silicon technology and overmolding techniques to provide a single in-line package with completely passive alignment between the various optical components. The technique as disclosed is useful in the packaging of a single active optical device and associated electronics, a pair of optical devices and electronics (transceiver), or an array of any desired number of such components. Since the silicon may be processed to include etched alignment fiducials and metallized bond pad sites, solder bump self-alignment and silicon optical bench technology may be used to provide for alignment between the active device, coupling lens and associated optical fiber.

Abstract: A graphite path is formed along the surface of a diamond plate, preferably a CVD diamond plate, by means of a laser or ion-implantation induced conductivity. The path advantageously can be the surface of a sidewall of a via hole drilled by the laser through the plate or a path running along a side surface of the plate from top to bottom opposed major surfaces of the plate. The graphite path is metallized, as by electroplating or electroless plating. In this way, for example, an electrically conducting connection can be made between a metallized backplane located on the bottom surface of the plate and a wire-bonding pad located on the top surface of the plate.

Abstract: Congestion control is implemented at the resources that actually suffer from congestion and, moreover the congestion control is performed within the network as well as at its access points. In a particular embodiment, congestion control is continuously performed at each resource. Use of each resource is controlled according to a head-of-the-line weighted round-robin service discipline thereby assuring fairness and full use of bandwidth for all active channels. Also, in order to control conditions of congestion, the queue of data elements waiting for service at each resource is regulated by a global congestion indicator for the entire queue. The data elements of each channel that are waiting for service are further regulated in response to specific local congestion indicators that are individualized for each channel. The global and local congestion indicators are used to guarantee predetermined levels of service for each channel.

Abstract: Disclosed is a device for electrically coupling stocked circuit boards using conductive polymer interconnect material and a spacer element. In one embodiment, coaxial connection is provided by means of an array of wires within undulating metal envelopes. In another embodiment, pins are provided within holes in a plastic spacer. In a third embodiment, wires are laid on a substrate and successive laminations are built up to form the spacer element. In a fourth embodiment, wire arrays are extrusion molded within thermoplastic sheets which are laminated to form the spacer element.

Abstract: A remote terminal for a subscriber loop carrier network operates by flow from one to another of units in the terminal of time division multiplexer data streams of binary valued digital bits. Each stream has the format of periodic frames of time slots of which each frame consists of (a) a service time slot containing only service bits, and (b) a plurality of customer slots which contain mostly bits coded with data from customers of the network, but which also include a less number of service bits. Each unit includes encoding means responsive to local synchronizing and clock pulses derived from data incoming to the unit to encode on each frame of the outgoing data stream synchronizing information consisting of (c) a synchronizing pattern comprising a coded sequence of service bits localized in the frame's service slot and (d) a spoiler pattern formed of service bits distributed over customer slots in the frame.

Abstract: A wire stripper (10) for stripping an outer insulative jacket from a cable (12) includes a frame (14) which carries a cable clamp (16) for releasably clamping the cable. The frame also carries a slitting mechanism (43) which includes a rotatable blade carrier (46) and a central passage (48) through which the cable passes. The blade carrier includes a pair of blades (60--60) each radially movable within a separate one of a pair of diametrically opposed slots (56--56) so as to circumferentially slit the insulative jacket when the blade carrier is rotated in a first direction. A gripping mechanism (94) is slidably mounted to a pair of rails (100--100) carried by the frame for gripping a portion of the cable downstream of the blade carrier so as to pull the severed portion of the outer insulative jacket from the cable when the gripping mechanism is displaced by a lever (108).

Abstract: A semiconductor memory cell with parallel gates is disclosed. The direction of the gates is desirably chosen to minimize lithographic astigmatic effects. Thus gates of comparatively uniform width are produced and predictability of transistor performance thereby improved. Another embodiment of the invention features a connection between two conductive layers and a source/drain. The connection forms a node between one access transistor and one pull-down transistor.