基于电流复用技术的LC压控振荡器

Realization of a Novel LC Voltage Controlled Oscillator with Current-Reuse

介绍了一种改进的LC压控振荡器。该电路采用电流复用技术维持有源负阻的相对稳定,有效增大了输出摆幅,同时没有尾电流上混频引入的1/f噪声,大大减小了相位噪声。另外,与常规VCO不同,采用开关阶跃电容结构,在一定程度上增大了可变电容的调节范围。采用TSMC 0.18μmRF CMOS 1P6M工艺,仿真得到在1.25 V基准电压下供电时,可有950~1050 MHz的线性调节范围,在中心频率1 GHz频偏1 MHz时的相位噪声为-129.3 dBc/Hz,功耗为4.1 mW。

A novel LC voltage controlled oscillator was presented,in which current-reuse technology was employed to reduce effect of negative resistance and improve phase noise.Instead of using inversed-MOS varactors in conventional VCO,the new VCO adopted switched step capacitors to increase tuning range of the varactor.The oscillator was implemented in TSMC＇s 0.18 μm RF CMOS 1P6M process.Simulation result showed that the proposed VCO had a tuning range from 950 MHz to 1050 MHz and a phase noise of-129.3 dBc/Hz at 1 MHz offset from 1 GHz center frequency,while dissipating 4.1 mW of power from a 1.25 V supply.