Patent ID: 6426679
Filing Date: 2002-07-30
Classification: G04F,H01S,H03L

Abstract:
An atomic frequency standard, comprising:(A) a digital control means operable to provide control signals; (B) a physics package including a) a cell containing an active medium, b) a microwave cavity adjacent said cell, c) a light source for projecting a light beam through said cell to optically pump said active medium, and d) a detector positioned to provide output signals to said digital control means in response to said light projected through said cell; (C) a regulator circuit operable, in response to control signals from said digital control means, for governing operation of said light source; (D) an rf frequency synthesizer including a) a reference oscillator providing a reference signal, b) a voltage controlled oscillator providing a microwave signal, c) a fractional-N frequency synthesizer having first and second inputs, d) first means applying said reference signal to said first input, e) second means applying said microwave signal to said second input, f) said fractional-N frequency synthesizer being connected to receive control signals from said digital control means and operable to fractionally divide said signal applied to said second input and compare the results with an indication of said reference signal applied to said first input, to provide an error signal for controlling operation of said voltage controlled oscillator; and (E) means for applying said microwave signal to said microwave cavity.