A Frequency Reference for Carrier Synthesis in Wireless Standard 802.11g

A new approach to a frequency synthesizer is proposed: instead of a fixed frequency reference oscillator and a variable ratio frequency divider we use a variable frequency reference oscillator and a fixed ratio frequency divider. The implementation and characterization of a low phase-noise compensated oscillator used as frequency reference for a wireless transceiver is described. This circuit employs a high Q piezoelectric resonator together with a CMOS cross coupled pair amplifier. A calibration circuit for compensation of frequency errors with respect to process variation is proposed.