可键控高频频率合成器的设计

Design of Controllable High Frequency Synthesizer

频率合成是将一个高稳定度和高精度的基准频率经过四则运算,产生同样稳定度和准确度的任意频率的技术。文中采用可编程数字频率合成芯片MC145151-2,结合单片机技术对频率步进值和输出频率值进行选择和控制,实现频率设置的程控化,完成输出频率在90 MHz^110 MHz范围变化的高频频率合成器的设计。阐述了该高频频率合成器软、硬件设计过程和参数计算方法,并对其进行各指标测试,结果表明该频率合成器具有较低的相位噪声、很高的频率稳定度。

The technology of frequency synthesizer is an art which obtains form benchmark frequencies arithmetic, and then produces needful arbitrary frequency, meanwhile, this synthetical frequency is as stable and reliable as its benchmark frequency. In this paper, programmable digit frequency synthesizer chip MC145151-2 is used to design high frequency synthesizer which frequency can scale 90 MHz - 110 MHz, and the single chip computer is also adopted to choose and control the step frequency value and output frequency value and then set frequency value by programming. The software and hardware design of this synthesizer is introduced, and the method for caculating the related parameters is given. And then, we test each index, it shows that the characters of our frequency synthesizer are low phasic noise and nice frequency stability. The result of the test shows that the design is rational and practical.