Litef Gmbh

Litton Systems, Inc.

Gunter Spahlinger

Sven Voigt

Mauricio Ribes

Hanns-Jurgen Buschelberger

Wolfram Busching

Erhard Shlenker

Erhard Schlenker

A device for current measurement based on a fiber-optic in-line Sagnac interferometer includes a birefringence phase modulator for non-reciprocal phase modulation of two orthogonal polarization modes of a light beam passing through the interferometer. The phase modulator is a digital phase modulator that is directly digitally drivable to permit simplification of the corresponding signal processing or driving electronics unit.

Current measurement method and device based on a fiber optic in-line Sagnac interferometer

A synchronous serial bus with timing information implemented in the bus standard protocol is provided for a bi-directional serial multi-channel data interchange between locally dedicated measuring instruments in a distributed configuration and/or with a data processing unit. This provides synchronized interchange of data between the instruments wherein each instrument is provided with an allocated controller. The invention permits one to employ a simple, preferably standardized, bus protocol. Wiring structure is considerably simplified for a complex multi-sensor system.

Apparatus for synchronized data interchange between locally dedicated

Method and device for speech encryption and decryption in voice

A method and apparatus for stabilizing the scale factor and the loop gain of the control loop of a fiberoptic Saganc interferometer with phase resetting. A digital evaluation circuit includes two auxiliary control loops, one for nominal gain of the scale factor control and the other for stabilization of loop gain of the primary control loop, in addition to the control loop for the readjustment of the phase modulator. The evaluation circuit can be realized as an integrated circuit. In addition to the optimization of control bandwidth, the circuit avoids substantial complexity of the circuit subassemblies for generating modulation and demodulation signals and control signals for the scale factor control loop.

Method and apparatus for stabilizing control loop scale factor and gain

A method for achieving an initial synchronization and matching a receive filter of a digital receiver of a binary baseband transmission system by employing a training sequence before the transmission of useful data. The coefficients of the digital filter that is to be matched to the received signal are obtained by means of the training sequence. Character synchronization and recognition of the end of the sequence occur automatically. After the training sequence is received, an optimally matched receive filter in the receiver is made available. The method is independent of the level of the received signal within a predetermined computing accuracy and can be implemented by means of a conventional signal processor system.

Synchronization and matching method for a binary baseband transmission

An open loop fiber optic rotation rate sensor of the type that is subject to bias errors arising from the coupling of disturbing signals into the input of a demodulator. Such errors are suppressed by the use of a demodulation signal that is statistically independent of all signal sources that may cause disturbing signals. A modulation signal generator includes a random number generator from which two signals (b.sub.0, b.sub.1) for a statistically alternating bias for activating optimal working points on the interferometer characteristic with positive or negative gradient and an appropriately matched demodulation signal (d) are derived. The demodulation signal, after transit time correction, acts upon the synchronous input of the synchronous demodulator.

Fiber optic sagnac interferometer with digital phase modulation for

A fiber optic interferrometer rotation rate sensor is reset by phase ramp via a digital control circuit using as demodulation signal within the control circuit a signal (d) that is statistically independent of all parasitic signals and originates from a modulation signal generator that includes a random number generator. A reversal of the phase modulator signal is provided in a statistically distributed manner to integral values of .pi./2 of the interferometer characteristic. The arrangement avoids deadband and removes scale factor nonlinearities, particularly at low rates of rotation.

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Stuttgart, Germany

Gunter Spahlinger