Frequency standard generator synchronized with satellite or other communication network reference clocks

A frequency standard generator for generating an high accuracy reference frequency signal, comprising:

• a voltage controlled crystal oscillator for generating high stability output signal to be used as a standard frequency signal;
• a receiver which receives a communication signal and reproduces a highly accurate reference time signal to be used as a reference for said voltage controlled crystal oscillator;
• a frequency divider which divides said output signal of said voltage controlled crystal oscillator by a dividing ratio arranged to generate a crystal time signal which is identical in frequency to said reference time signal;
• a time interval measuring circuit which measures a time interval between said reference time signal and said crystal time signal and generates a digital signal indicating said time interval;
• a frequency control processor which arithmetically determines control data based on said digital signal from said time interval measuring circuit such that said time interval maintains a constant value through an operation of a phase lock loop, said control data is a function of parameters including a variation of said time interval, an integration constant of said phase lock loop and a proportional constant of said phase lock loop, said parameters being determined at a repetition rate which is substantially smaller than a period of said reference time signal;
• and
• a D/A converter which converts said control data from said frequency control processor to an analog voltage which is used to control the output frequency of said voltage controlled crystal oscillator.