一种超低功耗低相噪FBAR振荡器  

An Ultra-Low Power and Low Phase Noise FBAR Oscillator

作　　者：黄继伟[1] 童乔 TONG Qiao HUANG Jiwei;TONG Qiao(Fujian Integrated Circuit Design Center,Fuzhou University,Fuzhou 350108,P.R.China)

机构地区：[1]福州大学福建省集成电路设计中心,福州350108

出　　处：《微电子学》2021年第4期477-481,共5页Microelectronics

基　　金：国家自然科学基金面上项目(61774035)。

摘　　要：提出了一种基于薄膜体声波谐振器(FBAR)的差分Colpitts振荡器。相比于传统Colpitts振荡器,该差分Colpitts振荡器移除了尾电流源,减少了近偏频相位噪声。交叉耦合差分对与耦合变压器的结合提高了有效负跨导,减小了振荡电路对启动电流的要求,增加了低电源电压下的输出摆幅,降低了相位噪声。该振荡器工作于C类状态,有效提高了电流利用率,保证电流相等条件下达到更好的相位噪声性能。选用具有高Q值的1.865 GHz-FBAR作为振荡器的谐振腔,CMOS电路基于SMIC 55 nm RFCMOS工艺完成。仿真结果表明,在0.6 V电源电压下,输出载波频率为1.876 GHz, 1 kHz偏频、1 MHz偏频时相位噪声分别达-84 dBc/Hz、-146 dBc/Hz,功耗仅为83μW,整体FOM值为-225 dB。A thin film bulk acoustic wave resonator(FBAR)-based differential Colpitts oscillator was presented. Compared to the traditional architectures, the proposed Colpitts oscillator removed the tail current source to reduce the phase noise. The combination of the cross-coupled pair and transformer in the oscillator increased the effective gm, reduced the star-up current requirement, increased output swing under a lower supply voltage, and reduced the phase noise. The oscillator operated in a Class-C state by adjusting the bias voltage. The current utilization was effectively improved to reduce the phase and the power consumption. The 1.865 GHz-FBAR with high Q value was used as resonant network of the oscillator, and the CMOS circuit was completed in the SMIC 55 nm RFCMOS process. Simulation results showed that the output carrier frequency was 1.876 GHz under 0.6 V voltage supply. This oscillator achieved a phase noise of-84 dBc/Hz,-146 dBc/Hz at 1 kHz, 1 MHz offset frequency respectively. The power dissipation was only 83 μW, and the FOM value was-225 dB.

关 键 词：FBAR 振荡器 变压器 时钟源 C类 

分 类 号：TN752[电子电信—电路与系统]