Abstract: This paper presents a wide tuning range CMOS frequency synthesizer for a dual-band GPS receiver,which has been fabricated in a standard 0.18μm RF CMOS process.With a high Q on-chip inductor,the wide-band VCO shows a tuning range from 2 to 3.6GHz to cover 2.45 and 3.14GHz in case of process corner or temperature variation,with a current consumption varying accordingly from 0.8 to 0.4mA,from a 1.8V supply voltage.Measurement results show that the whole frequency synthesizer consumes very low power of 5.6mW working at L1 band with in-band phase noise less than -82dBc/Hz and out-of-band phase noise about -112dBc/Hz at 1MHz offset from a 3.142GHz carrier.The performance of the frequency synthesizer meets the requirements of GPS applications very well.

Key words: PLL, GPS, frequency synthesizer, VCO, low power, CMOS RF