摘要
将直接数字频率合成技术与传统间接频率合成技术相结合，应用于无线寻呼测试系统，使国产无线寻呼机测试产品的性能指标提高到一个新水平：其中频率分辨率小于1Hz；进行四电平调制时可不用外接专用编码器，直接由软件来实现数字调制；频率信号频谱纯净，谐波较少．在设计中采用价格较低的12．8MHz温补型晶振（且与单片机共用），实现了132～320MHz大范围变化的频率输出．通过实验，在以512bits／s及1200bits／s的速率调制时，仪器完全可以满足使用要求，且具有较高的性能价格比．
The advanced technologies of Direct Digital Synthesis(DDS) and traditionalIndirect Synthesis (IS) are used in the pager testing instruments,therefore native product'squalities are improved. Compared with the past instriments, it has a less output tuningresolution(< 1Hz) and a higher accuracy, and can realize digital frequency modulation.The output frequency of the equipment ranges from 132 MHz to 320 MHz. Byexperiments the instrument can essentially come to designing requirement. Its rate offrequency transformation can meet the speed of 512bits/s and 1200bits/s.
出处
《北京服装学院学报（自然科学版）》
CAS
2000年第1期32-35,共4页
Journal of Beijing Institute of Fashion Technology：Natural Science Edition
