Patent ID: 6359476
Filing Date: 2002-03-19
Classification: H03B,H03L

Abstract:
A frequency correction circuit, comprising:a clock circuit generating a reference frequency signal exhibiting a first frequency; a phase detector producing phase error signals representing sensed phase deviations in said reference frequency signal; a control circuit generating, in correspondence with said phase error signals, frequency and phase instruction signals corresponding to corrections of said phase deviations by a designated reference signal from a selected frequency due to changes in said first frequency indicated by said phase error signals, and generating control signals; and a direct digital synthesizer operationally driven by said reference frequency signal and said control signals, with said frequency and phase instruction signals applied to modulate said reference frequency signal during generation of said designated reference signal exhibiting said selected frequency; wherein said control circuit: performs an algorithmic computation of said frequency and phase instruction signals indexed by said sensed phase deviations; and comprises a controller synchronized by said reference frequency signal, reading values of said frequency and phase instruction signals, generating said control signals and applying said values of said frequency and phase instruction signals to control said generation of said designated reference signal.