This paper presents a VHF CMOS VCO. The most significant improvement on the VCO is that the cross-coupled MOSFET pairs are divided into several switchable parts so the characteristics can compensate the state change that results from the frequency tuning of the oscillator. This VCO is implemented in 0, 18μm CMOS with a core area of about 550μm × 700μm. The test results show that the tuning range covers 31-111MHz with a power consumption between 0.3-6. 9mW and a phase noise at a 100kHz offset of about - 110dBc/Hz.
回顾了对MOS LC差分振荡器的认识现状。通过简单的推导和Van der Pol方程现有结论,得到了交叉耦合MOS特性对振荡器性能的影响。这些结论包括:1)起振条件;2)输出幅度与参数间的解析表达式;3)振荡器输出频率与LC谐振回路和交叉耦合MOS管非线性特性影响的关系;4)过渡过程的时间常数;5)振荡器输出的谐波特性。这些结论揭示了MOS LC差分振荡器新的现象,对设计者了解振荡器的工作状态和优化设计有一定的参考意义。
The design and implementation of a CMOS LC VCO with 3. 2-6. 1GHz tuning range are presented. This is achieved by enhancing the tuning capability of the binary-weighted band-switching MIM capacitor. The circuit has been implemented in a 0. 18μm RF/Mixed-Signal CMOS process. The measured phase noise is - 101.67dBc/Hz at 1MHz offset from a 5.5GHz carrier,and the VCO core draws 9.69mA current from a 1.8V supply.
