一种高性能宽带LCVCO的设计

Design of a High Performance LC VCO for Broadband Application

基于TSMC65nmCMOS工艺，采用电流偏置型差分负阻结构，设计了一个宽频率覆盖范围（7．6～10．7GHz）的电感电容谐振压控振荡器（LCVCO）。采用差分控制电压方式，减小共模噪声对VCO性能的影响。采用三组可变电容共同作用的方式，减小VCO增益随振荡频率的变化，同时实现频率的温度补偿。创新性地采用一种新型开关结构，在基本不增加面积的情况下，优化了LCVCO的相位噪声性能。将该LCVCO用于为4．2～5GHz双沿采样DAC提供时钟的锁相环电路，实现了良好的相位噪声性能。

Based on TSMC＇s 65 nm CMOS process, an LC voltage controlled oscillator （LC VCO） with current- biased differential negative-resistance structure was designed for broadband （7. 6 -10. 7 GHz） application. In this circuit, differential voltage control was used to reduce effects of common-mode noise on performance of the VCO, and variation of VCO gain with oscillating frequency was reduced by interaction of three sets of varactors. Moreover, a new type of switch structure was adopted to optimize phase noise performance of the LC VCO, with no additional chip area. This LC VCO was applied to a phase-locked loop, which provides clock signal for 4. 2 - 5 GHz dual-edge sampling DAC, and excellent phase noise performance was achieved.