Patent ID: 6639476
Filing Date: 2003-10-28
Classification: H03L

Abstract:
A digitally tuned synthesizer comprising:a) register means for receiving a digital word having a predetermined number of bits; b) means interconnected to said register means for partitioning said predetermined number of bits of said digital word into coarse and fine control words; c) a first digital to analog converter connected to said coarse control word and providing an output representative of said coarse control word; d) at least one voltage controlled oscillator having first and second inputs with the first input connected to said output of said first digital to analog converter and providing a RF output representative of its first and second inputs; e) a frequency measurement circuit connected to the output of said at least one voltage controlled oscillator and providing an output representative thereof; f) a first adder having plus (+) and minus (âˆ’) inputs, said plus (+) input being connected to said fine control word, said minus (âˆ’) input being connected to said output of said frequency measuring circuit, said first adder having an output representative of the difference between its inputs; and g) a second digital to analog converter connected to said output of said first adder and providing an output representative thereof that is connected said second input of said at least one voltage controlled oscillator.