小型低相噪恒温晶体振荡器设计

Deign of Miniature OCXO With Low Phase Noise

根据用户需要,该文设计了一种小体积低相噪40 MHz恒温晶体振荡器。该振荡器采用低噪声线性稳压器(LDO)作为电源、SC-切晶体谐振器及B模抑制网络等设计,在减小体积的同时提高了产品的相位噪声。温控系统采用直放式加热电路,比例积分的算法,有源负载作为加热元件,提高产品的控温精度,降低环境温度变化对振荡器带来的影响。该振荡器工作稳定可靠,工作电压仅为5 V。其温度-频率特性绝对值不大于0.02×10^-6(-30^+70℃),相位噪声不大于-160 dBc/Hz@1 kHz的指标。功耗仅为0.9 W,体积仅为20 mm×12 mm×10 mm。

A miniature 40 MHz OCXO with low phase noise is designed according to the use needs.The oscillator is designed with low noise LDO as power processing,SC-cut crystal resonator and B-mode restrained network.The phase noise is improved while the size is reduced.The temperature control system adopts the direct heating circuit,the proportional integral algorithm,and the active load as the heating element to improve the temperature control accuracy of the product and reduce the influence of the ambient temperature change on the oscillator.The oscillator is stable and reliable,operating at only 5 V.The obsolute value of frequency-temperature characteristic is not more than 0.02×10-6(-30^+70℃),and the phase noise is not more than-160 dBc/Hz@1 kHz.The power consumption is only 0.9 W and the size is only 20 mm×12 mm×10 mm.