Adv Antest Corporation

Hitoshi Ujiie

Takeshi Konno

Kazuyuki Maruo

A frequency standard generator includes a voltage controlled crystal oscillator (VCXO) for generating high stability output signal, a radio wave receiver to receive a radio wave which includes a high accuracy reference time signal, a time interval measuring circuit which measures a phase difference between the reference time signal and the output signal of the VCXO; a frequency control processor which determines control data based on the phase difference data to phase lock the output signal of the VCXO to the reference time signal, a frequency deviation data generator for compiling the phase difference data to obtain frequency deviation trend data of the VCXO, and a compensation data generator for generating compensation data based on the frequency deviation trend data to compensate frequency changes in said VCXO when the reference time signal is unavailable.

Standard frequency and timing generator and generation method thereof

A frequency standard generator for generating a high accuracy reference frequency by synchronizing a high accuracy atomic frequency standard or equivalent thereof and minimizing a phase difference between the generated reference frequency and the received atomic frequency standard. The frequency standard generator includes a voltage controlled crystal oscillator (VCXO) for generating high stability output signal to be used as a standard frequency signal, a radio wave receiver which receives a radio wave and reproduces a time signal to be used as a reference for the VCXO, a time interval measuring circuit which measures a phase difference between the time signal and the output signal of the VCXO and generates data indicating the phase difference, a frequency control processor which produces control data to control the frequency of the VCXO such that the phase difference maintains a constant value through an operation of a phase lock loop, a phase controller which initiates a phase control operation for reducing the phase difference for a predetermined period of time, and a D/A converter which converts the received data to an analog voltage to be supplied to the VCXO.

Frequency standard generator

A pulse generator is provided with a photoconductor in which first to third transmission lines composed of conductive film are formed on a semi-insulating substrate and the transmission lines are separated by first and second narrow gaps, and provides short pulses from short electrical pulses generated on these transmission lines in accordance with short optical pulses irradiated upon each narrow gap. Semiconductor lasers effect the irradiation of short optical pulses upon the first and second narrow gaps. A delay is conferred upon short optical pulses irradiated upon one of the first and second narrow gaps such that pulse height of short electrical pulses generated on the first to third transmission lines is maximized.

Pulse generator and pulse generation method having maximized pulse height

A frequency standard generator includes a voltage controlled crystal oscillator for generating high stability output signal to be used as a standard frequency signal, a satellite wave receiver which receives a radio wave from a satellite which includes a highly accurate satellite time signal and reproduces the satellite time signal to be used as a reference for the voltage controlled crystal oscillator, a frequency divider which divides the output signal of the voltage controlled crystal oscillator by a dividing ratio arranged to generate a crystal time signal which is identical in frequency to the satellite time signal, a time interval measuring circuit which measures a time interval which is a phase difference between the satellite time signal and the crystal time signal and generates a digital signal indicating the phase difference, a frequency control processor which arithmetically determines control data based on the digital signal from the time interval measuring circuit such that the phase difference maintains a constant value through an operation of a phase lock loop, and a D/A converter which converts the control data from the frequency control processor to an analog voltage which is used to control the output frequency of the voltage controlled crystal oscillator.

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Sendai, Japan

Hitoshi Ujiie