低调谐增益变化的10 GHz电感电容式压控振荡器设计

Design of a 10 GHz LC-VCO with low tuning gain fluctuation

基于0.18μm CMOS工艺,设计了一种应用于无线通信和雷达系统的低变化调谐增益的电感电容式压控振荡器。该电路包括分布式偏置可变电容阵列和开关电容阵列,合理选择偏置电压扩展电容-电压曲线覆盖范围,在整个调谐电压范围内,可有效降低调谐增益。三位开关电容阵列将整个可调频率范围分为8个子频带,通过控制可变电容实现子频带内频率的调谐范围。同时采用开关可变电容阵列,有效抑制了电感电容式压控振荡器调谐增益的变化。基于1P6M 0.18μm工艺模型的后仿真结果显示该10 GHz压控振荡器调谐增益变化率表现优异,低至21.5%,调谐频率范围为9.13~11.15 GHz,同时该压控振荡器能够实现较低的直流功耗9 mW(1.8 V电源电压),相位噪声在10 GHz时为-105 dBc/Hz@1 MHz。

Based on 0.18μm CMOS process,a low-variable tuning gain LC-VCO(inductance capacitance-voltage controlled oscillator)was designed for wireless communication and radar systems.The circuit includes a distributed bias varactor array and a switched capacitor array,a reasonable selection of the bias voltage can achieve the purpose of expanding the C-V(capacitance-voltage)curve,thereby effectively reducing the tuning gain within the entire tuning voltage range.The three-bit switched capacitor array divides the entire adjustable frequency range into 8 sub-bands,which is implemented by controlling the varactor array.And the switched varactor array is adopted,which can effectively suppress the variation of the LC-VCO tuning gain.Based on the model of 1P6M 0.18μm technology,the post-layout simulation results show the good performance on property of tuning gain variation rate,which is 21.5%with the frequency tuning range from 9.13 GHz to 11.15 GHz,at the same time,the VCO DC power consumption is 9 mW with 1.8 V supply voltage,the phase noise is-105 dBc/Hz@1 MHz when the VCO oscillating frequency is around 10 GHz.