前言随着无线电技术的发展及其应用日益广泛,特别是国防上如军事侦察、导航与雷达、导弹制导、卫星跟踪、宇宙通讯以及时间与频率计量等领域中,对振荡频率的稳定度提出了越来越高的要求。比如在无线电通讯系统中,如果发射机频率和接收机的本 Preface With the development of radio technology and its increasingly wide range of applications, especially in the field of national defense such as military reconnaissance, navigation and radar, missile guidance, satellite tracking, space communications and time and frequency measurement, the stability of oscillation frequency is proposed Higher and higher requirements. For example, in a radio communication system, if the transmitter frequency and the receiver of this