[20分][英语翻译]关于锁相环的介绍，如下

The frequency source is the importance of the modern electronics system to constitute part, is called many"heart"s of electronics systems.In the correspondence, radar with navigate etc. the equipments, it since shoot machine to encourage a signal source, and then is a receiver of native flap to concuss;In the electronics resist the equipments, it can be the interference signal occurrence machine;In the test equipment, it can be a standard signal source.Along with modern electrician's electronics technical of develop continuously, people's request to frequency source is more and more high.The function outstanding frequency source all synthesizes a technique through a frequency to carry out.The frequency synthesizes a technique, be become a basis frequency transformation a(or many) conforms to a quality request of the technique of frequency needed.Electric circuit or module which carry out frequency to synthesize are called frequency to synthesize a machine.自己翻的啊...<