说明：  这是花2000多元在华为培训时拷出的内部培训资料。 其中介绍了模拟电子电路元件在通信设备上的应用。 分晶体管 运算放大电路 振荡电路 锁相环 A/D D/A 滤波器 负反馈电路等
(This is training in Huawei spent 2,000 yuan out of the house when the copy training materials. Which describes the analog electronic circuit elements in the communication device applications. Sub-transistor operational amplifier oscillator PLL A/DD/A negative feedback circuit filter)