【摘要】 利用微机械可变电容作为频率调节元件,制备了一种中心频率为2GHz的LCVCO.微机械可变电容的控制极板与电容极板分离,并采用表面微机械工艺制造,在2GHz时的Q值最高约为38·462.MEMSVCO的测试结果表明,偏离2·007GHz的载波频率100kHz处的单边带相位噪声为-107·5dBc/Hz,输出功率为-13·67dBm.对微机械可变电容引起的机械热噪声以及减小空气压膜阻尼来降低相位噪声的方法进行了讨论,提出了一种优化阻尼孔数目的方法.更多还原

【Abstract】 A 2GHz LC VCO is fabricated using a micromachined variable capacitor for frequency tuning.The MEMS variable capacitors,whose controlling plates and capacitor plates are separated,are fabricated in a surface micromachining process.These devices have a quality factor of 38.462 at 2GHz.The MEMS VCO operating at 2.007GHz achieves a single side band phase-noise of -107.5dBc/Hz at a 100kHz offset from the carrier and an output power of -13.67dBm.On the basis of analysis of VCO mechanical-thermal noise produced from the micromachined variable capacitor,a method for lowering the phase noise by reducing the squeeze damping is proposed and an optimized number of damping holes is obtained.更多还原