Research Of Compensation And Processing Technique For Frequency Sources

With the rapid development of modern electronics technology, the performance requirement for crystal oscillator is more higher. For this purpose, this paper presents a novel type of microcomputer compensated crystal oscillator(MCXO). It is introduced in detail the operating principle, the system structure and the software designing of the MCXO. Firstly, this paper describes temperature performance and aging performance of quartz crystal oscillator,and compensate theory and compensate technique are given. Secondly, the paper introduces the design of hardware-circuit and its functions. The balance condition for colipitts oscillator circuit is analyzed. The principle and characteristics of voltage variable capacitance diode is discussed. RC filter circuit and temperature sensor are described in detail. Using microcomputer as system's core,the interpolation arithmetic of temperature curve and the ageing auto-compensation through fitting curve are achieved.At the same time, the size and power consumption of the system are largely decreased through the optimal design on hardware and software. The experimental results prove that the project is feasible and the capability is also satisfying.Because the technology of compensating wave and curve fitting are used in this MCXO, so the software plays its role sufficiently. Cooperating with simple circuits, this system is high in frequency stability, simple in structure, small in size,low in power and so on. It is fit for mass production. The performance of this MCXO is high in comprehensive index and application value.