摘要
This paper introduces a 2.5GHz low phase-noise cross-coupled LC-VCO realized in 0.35μm SiGe BiCMOS technology. The conventional definition of a VCO operating regime is revised from a new perspective. Analysis shows the importance of inductance and bias current selection for oscillator phase noise optimization. Differences between CMOS and BJT VCO design strategy are then analyzed and the conclusions are summarized. In this implementation, bonding wires form the resonator to improve the phase noise performance. The VCO is then integrated with other components to form a PLL frequency synthesizer with a loop bandwidth of 30kHz. Measurement shows a phase noise of - 95dBc/Hz at 100kHz offset and - 116dBc/Hz at 1MHz offset from a 2.5GHz carrier. At a supply voltage of 3V, the VCO core consumes 8mA. To our knowledge,this is the first differential cross-coupled VCO in SiGe BiCMOS technology in China.
介绍了一个基于0.35μm SiGe BiCMOS工艺的2.5GHz低相位噪声LC压控振荡器.文章重新定义了压控振荡器工作区域.分析表明谐振回路的电感值和偏置电流对振荡器的相噪优化有重要的影响.本文同时分析了CMOS和BJT压控振荡器设计思路的不同.本设计中,采用键合线来实现谐振回路中的电感来进一步提高相噪性能.该VCO和其他模块集成在一起实现了一个环路带宽为30kHz的频率综合器.测试结果表明,当中心频率为2.5GHz时,在100kHz和1MHz的频偏处相噪分别为-95dBc/Hz和-116dBc/Hz.工作电压为3 V时,VCO核心电路的电流消耗为8mA.据我们所知,这是国内第一个采用Si Ge BiCMOS工艺的差分压控振荡器.
基金
国家自然科学基金(批准号:60276021)
国家重点基础研究发展规划(批准号:G2002CB311901)资助项目~~
