摘要
为了在不影响校准分辨率的情况下减小压控振荡器的频率校准时间,提出了一种拥有混合校准过程的频率校准技术.该校准技术先利用相对频率比较方法来检测和减小当前频率子带与目标频率的偏移量,当频率子带靠近目标频率时,再使用频率误差检测方法获得高精度的校准分辨率.凭借着快速相对频率比较过程和高精度频率误差检测过程,压控振荡器获得2MHz校准分辨率所需的时间仅为2.77μs.与传统频率误差检测技术相比,在相同校准分辨率的情况下,该技术的校准时间减少了31%.此外,该校准技术适用于多位宽开关电容阵列的分数频率综合器.
A frequency calibration technique with the hybrid calibration process is proposed to reduce the calibration time of the voltage-controlled oscillator(VCO)and maintain the fine calibration resolution.The calibration technique begins by employing the relative frequency comparison method to discern and decrease the difference between the frequency tuning curve and the target frequency.When the frequency tuning curve is close to the target frequency,the calibration technique changes to utilize the frequency error detection method to achieve a fine calibration resolution.With the fast relative frequency comparison process and the high-accuracy frequency error detection process,the calibration time for a frequency resolution of 2 MHz is only 2.77μs.Compared to the conventional binary searcher process by only employing the frequency error detection method,the proposed technique saves 31% of the calibration time under the same calibration resolution.Furthermore,this calibration technique is suitable for the wideband fractional-N frequency synthesizer.
引文
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