Abstract: A disk-drive-compatible magnetic tape cartridge is provided with a tape guide for accurately positioning a magnetic tape in relation to a disk drive head. The tape guide includes a positioning section to be aligned with a rotation axis of a center core assembly when the center core assembly is chucked on a turntable of the disk drive. The tape guide also includes a guide section defining a tape run path across the disk drive head. The guide section is formed integrally with the section to be aligned with the center core assembly and so distanced from the latter as to accurately position the magnetic tape with respect to the disk drive head. Since the tape guide has the positioning section and guide section integrally, the distance therebetween can be maintained precisely constant. Therefore, tracking by the disk drive head becomes easier to allow high-density recording.

Abstract: An N ring element ring oscillator merged with an M element ring oscillator by using a linear combining circuit. By adjusting the control voltage, the oscillation frequency can be varied from 1/2*N*T.sub.d (where T.sub.d is a gate delay) to 1/2*M*T.sub.d. Other embodiments provide extended frequency tuning range.

Abstract: A molecular beam epitaxy (MBE) process in which some portions of the substrate are shadowed by a shadow mask from receiving at least one of the molecular beams used in the MBE process. This process is capable of producing NIPI superlattices that have selective contacts that are far superior to those which can be produced at present. This technique can also produce a wide variety of NIPI devices as well as other types of IC structures.

Abstract: A CVD furnace, having a gas seal and a liquid seal, for chemical vapor deposition of a coating on a fiber. A CVD process utilizing the CVD furnace allows fibers to be pulled through the furnace without drawing gases entrained by the moving fiber into the reaction chamber of the furnace. The process is a hot fiber process, preferably deriving its heat from the meltdown point in an optical fiber pulling process. A coat containing carbon is applied by supplying a reactant containing a carbon having a triple bond. A small amount of silane is also supplied to the reaction chamber to act as an oxygen getter and to prevent tar-like reaction products from clogging the furnace.

Abstract: Circuit imperfections in phase modulators will introduce offsets in the servo error signals in frequency locking circuits. Such offsets will also cause a frequency offset. The frequency offset is first reduced by reducing or removing amplitude modulation at the modulating frequency in the modulated carrier signal. In the preferred embodiment, this is accomplished by a coupled servo which includes a matrix loop filter. After the amplitude modulation at the modulating frequency has been removed, sideband imbalance can be corrected by amplitude modulating the modulating signal so that the offset caused by sideband imbalance is reduced or eliminated. This will be the case provided that the integral of at least the third power of the amplitude modulation vanishes.

Abstract: A pulse compressor consisting of a loaded transmission line having a pluraltiy of sections which have a ratio of dispersion to nonlinearity that decreases in the direction of pulse transmission.

Abstract: A travelling wave modulator in which the phase velocity of a first wave is modulated by a second travelling wave. Means are provided to alter the polarity of the second wave in accordance with a pseudorandom code. Barker codes and Golay codes are particularly suitable for improving the bandwidth-to-voltage ratio of the modulator over a comparable conventional modulator.

Abstract: A sampler that can be used to sample optical or electrical signals, having an improved sensitivity-resolution product compared to conventional samplers. A coded switched electrode modulator has electrodes that produce polarity reversals in an applied voltage signal in accordance with a pseudorandom code having small sidelobes. An optical signal is injected into an optical waveguide that is oriented parallel to the electrodes. When the optical signal is proportional to the coded electrode pattern, the device is used as an electrical sampler. When the applied voltage signal is proportional to the coded electrode pattern, the device is used as an optical sampler.

Abstract: A selective contact to a NIPI doping superlattice having a trap free (or low trap density) contact in contact with the layers of the superlattice. In a NIPI superlattice, the trap free region is a doped region that can be produced: by diffusion of dopant ions from a doped metal contact; by overdoping of the edges of the superlattice; or by overgrowth of the edges of the superlattice with a doped material that is trap free.

Abstract: A mixer is presented which utilizes a diode bridge having a first input signal imposed across two opposite nodes of the diode bridge and having a second input signal imposed across the other two nodes of the diode bridge. A set of variable impedance devices are included in the mixer to protect the diodes in the diode bridge from overload conditions. These variable impedance devices can be included in each leg of the diode bridge or can be included in the input leads to the loop. The variable impedance devices control the current through the diodes by having a low impedance under non-overload conditions and having a high impedance under overload conditions. A particularly simple choice of the variable impedance device is a FET which has its gate shorted to its source.

Abstract: A method of dynamically changing the measurement window and operating parameters of the instrument, based on intermediate results, in order to minimize the total time required to make a complete measurement. Also, a method of combining partial results from subwindows into a final result to be displayed that has not been corrupted by variation in system response due to time-varying operating parameters.

Abstract: Deconvolution of up to three overlapping chromatographic peaks is provided in which pure spectral components are extrapolated from a Euclidean-normalized expression of chromatographic data in the space of the three principal factors. A coordinate transformation to planar coordinates after expansion in factor space and before extrapolation yields the simplicity of linear extrapolation in combination with the inherent accuracy of Euclidean, as opposed to standard, normalization. The estimation of the pure component spectra permits the constructions of a concentration matrix. Improved estimates and an error bound are provided by applying assumptions of non-negativity and limited deviation from the means to the concentration matrix.

Abstract: A joystick controller includes three gravity sensing switches, the outputs of which can be used in the assignment of joystick transducer outputs in six different ways depending on controller orientation. This permits intuitive control of a robot arm in that translational motions can always be effected by moving the joystick in the direction the arm is to move. Thus, a controller which is economical, reliable and intuitive multiplies the functions available from what is basically a two or three dimensional controller.

Abstract: An improved digital testing device is presented which includes the capability to detect and avoid a pair of common sources of measurement error. One source of error occurs when measurements are made within a Setup time before a transition in the signal under test or during a Hold time after such a transition. This device includes the ability to detect when this occurs and to insert a relative delay between the measurements and transitions to eliminate such errors. The device also detects the existence of a 3-state condition of a point of the circuit under test during the period of a measurement and provides an output indication when such occurs.

Abstract: A connector having a center conductor contact whose length relative to an enclosing outer conductor contact can be adjusted to make a shoulder of the center conductor contact flush with the end of the outer conductor contact. In a female version of the connector, a cylindrical shell encloses a cavity in which a collette is inserted. An opening in a first end of the shell enables a male center pin to be inserted into the connector to make contact with the collette. The collette shape is such that the contacts between the collette and both the shell and the center pin are substantially at the opening of the first end of the shell. A spring on the other end of the collette presses the collette against the shell to produce wiping contacts at the opening.

Abstract: A tape cartridge adapted to utilize the read/write head(s) in a disc drive to read data from and/or write data to the tape. The tape cartridge has a section A having a size and shape which enables it to be inserted into the disc drive to locate a portion of the tape at a location L suitable for transferring data with the disc drive head(s). The tape cartridge includes: tape media; a means to register the tape media with respect to the read/write head(s) of a disc drive; a means for storing that portion of the tape media which is not contained within section A; and a means for feeding the tape media past the read/write head(s) in the disc drive. The tape cartridge may include a linkage that enables it to utilize the disc drive spindle motor to feed the tape. The linkage can also include a clutch to enable tape feed direction to be reversed.

Abstract: A bit-error-rate tester provides for testing of links with different numbers of channels without replacing or reconfiguring an included pseudorandom word sequence (PRWS) generator. The tester includes a transmitter and a receiver, each with generators for parallel evenly staggered pseudorandom bit sequence (PRBS) replicas collectively constituting the PRWS. The receiver generator is a copy of the transmitter generator so that it can predict the PRWS received from the transmitter. Comparators are provided so that incoming and locally generating sequences can be compared to determine bit error rates. Synchronization of the receiver generator is effected using a pattern detector coupled to at least one reception line. When a predetermined pattern is detected, an injector injects registers of the receiver generator with a predetermined bit pattern. Afterwards, the receiver generator autonomously generates its PRWS synchronously with the PRWS received from the transmitting generator.

Abstract: A tape cartridge containing a pair of spools between which tape is fed and containing a brake that can stop rotation of the spools when no power is being applied to feed the tape. A passive mechanical embodiment is shown in which tension in the tape is used to release the brake.

Abstract: An optical relay having a pair of simple lenses and an opaque barrier defining an aperture. In a spectrometer, the optical relay is positioned between a light source and an opaque barrier defining a slit to focus light of a reference wavelength w.sub.r onto the slit. The location of the aperture and the choice of w.sub.r are selected so that the flux of light through the slit is substantially flat as a function of wavelength.

Abstract: This shorts test method reduces the occurence of phantom shorts and also in those cases where phantom shorts occur, reduces the time required to eliminate the phantom shorts. When an unexpected open or short occurs or when an expected open or short does not occur, the test is repeated either until the phantom result ceases or until a sufficient time has elapsed that the result is real rather than a transient response. Test points are arranged in an order which decreases monotonically with the parallel impedance of all elements connected directly to that test point. This reduces the rate of occurance of phantom shorts caused by parallel inpedances below the shorts threshold even though none of the individual impedances is below the shorts threshold.