purity circuit

The paper discusses on DDS spectrum purity improvement, and gives the circuit scheme.

对如何提高DDS输出频谱纯度进行了探讨，并给出电路解决方案。

The source consists of a microwave phase-locked loop and a new type of automatic frequency control circuit. Chief factors to influence spectrum purity of microwave output signal and phase noise are analyzed.

该稳定本振源由一个微波锁相环路（PLL）和一种新型自动频率控制电路（AFC）组成，文中分析了影响微波输出信号频谱纯度和相位噪声的主要因素。

The production and application of photoresist, specialty chemicals for flat panel display, printed circuit board material, high-purity reagent, specialty gas and packaging material in China were summarized. At present, 1000 electronic chemicals can be produced in China in commercial scale or in batches.

综述了我国光刻胶、FPD专用化学品、印刷电路板材料、高纯试剂、电子特种气体和封装材料的生产和应用现状，目前我国能工业化生产或批量生产的电子化学品近1000种。