This paper describes a low phase noise, wide tuning range and high tuning linearity CMOS voltage controlled crystal oscillator IC （VCXO-IC） with LVCMOS and LVPECL output. A differential coupled frequency doubling Co...This paper describes a low phase noise, wide tuning range and high tuning linearity CMOS voltage controlled crystal oscillator IC （VCXO-IC） with LVCMOS and LVPECL output. A differential coupled frequency doubling Colpitts oscillator is adopted to obtain low noise 2x frequency output. Wide tuning range and high lin- earity are simultaneously achieved by using MOS varactor arrays. The measurement results show that the designed VCXO-IC achieves -134 dBc/Hz phase noise at 1 kHz offset frequency and 4-135 ppm output frequency tuning range within 3% linearity by using 40 MHz fundamental AT-cut crystal. The VCXO-IC is fabricated in the chartered 0.35/zm standard CMOS process and occupies a total silicon area of 2.4 mm2.展开更多
A voltage-controlled oscillator（VCO） with dual stages of accumulation mode varactors for a multimode global navigation satellite system（GNSS） application,which adopts sigma-delta fractional-N technology in the syn...A voltage-controlled oscillator（VCO） with dual stages of accumulation mode varactors for a multimode global navigation satellite system（GNSS） application,which adopts sigma-delta fractional-N technology in the synthesizer,is presented.The structure is selected to optimize the frequency coverage and tuning linearity, based on a general analysis of the parasitic capacitance in the coarse tuning switch bank cells,which cover the global positioning system（GPS） and Beidou（BD） bands.The VCO implemented in the 0.18μm CMOS process can cover the GPS L1,BD B1,B2 and B3 bands with sufficient margin,and exhibits low phase noise by using this tuning curve linearization technique.The equalized K_（vco）,characteristic behavior further offers a wide voltage tuning range and improves the stability of the closed loop.展开更多
基金Project supported by the National Natural Science Foundation of China(No.61350007)
文摘This paper describes a low phase noise, wide tuning range and high tuning linearity CMOS voltage controlled crystal oscillator IC （VCXO-IC） with LVCMOS and LVPECL output. A differential coupled frequency doubling Colpitts oscillator is adopted to obtain low noise 2x frequency output. Wide tuning range and high lin- earity are simultaneously achieved by using MOS varactor arrays. The measurement results show that the designed VCXO-IC achieves -134 dBc/Hz phase noise at 1 kHz offset frequency and 4-135 ppm output frequency tuning range within 3% linearity by using 40 MHz fundamental AT-cut crystal. The VCXO-IC is fabricated in the chartered 0.35/zm standard CMOS process and occupies a total silicon area of 2.4 mm2.
文摘A voltage-controlled oscillator（VCO） with dual stages of accumulation mode varactors for a multimode global navigation satellite system（GNSS） application,which adopts sigma-delta fractional-N technology in the synthesizer,is presented.The structure is selected to optimize the frequency coverage and tuning linearity, based on a general analysis of the parasitic capacitance in the coarse tuning switch bank cells,which cover the global positioning system（GPS） and Beidou（BD） bands.The VCO implemented in the 0.18μm CMOS process can cover the GPS L1,BD B1,B2 and B3 bands with sufficient margin,and exhibits low phase noise by using this tuning curve linearization technique.The equalized K_（vco）,characteristic behavior further offers a wide voltage tuning range and improves the stability of the closed loop.
