Voltage Controlled Oscillator
一种基于MEMS的射频低相位噪声压控振荡器的研制

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.