But PLLs design process involves much theory and application base, such as signal and system, integrated electronics, layout, semiconductortechnology, measurement etc.
但是锁相环的设计过程，涉及到信号与系统、集成电子学、版图、半导体工艺和测试等方面，难度比较大。
2
In this paper, a measuring instrument is designed based on relative measurement of the semiconductor laser frequency stability making use of the beat technology.