2.5GHz低相位噪声LC压控振荡器

A 2.5 GHz LC Voltage Controlled Oscillator with Low Phase Noise

在0．35μm SiGe BiCMOS工艺条件下，设计了一个全集成的低相位噪声LC压控振荡器（VCO）。该VCO采用尾电阻结构替代传统的尾电流源结构实现电流控制，以减小尾电流源产生的噪声。该VCO的调谐范围为480MHz，可以覆盖2．32～2．8GHz。当振荡频率为2．5GHz时，100kHz和1MHz频偏处的相位噪声分别为-104．3dBc／Hz和-124．3 dBc／Hz。振荡器工作电压为5V，尾电流为5mA。工作在2．5GHz时，其100kHz频偏处的性能系数为-178dBc／Hz。

A fully integrated LC voltage controlled oscillator （VCO） with low phase noise was designed using 0. 35 tan SiGe BiCMOS technology. In this VCO, instead of conventional tail current source, tail resistor structure was used for current control to reduce noise of tail current source. The VCO has a tuning range of 480 MHz, which is from 2. 32 GHz to 2. 8 GHz, and achieves low phase noise of -104. 3 dBc/Hz and -124. 3 dBc/Hz at 100 kHz and 1 MHz offset frequency from 2. 5 GHz carrier. The oscillator draws 5 mA from 5 V supply voltage. The figure-ofmerit （FOM） value at 2. 5 GHz is around -178 dBc/Hz at the offset frequency of 100 kHz.