基于C8051F020的频率特性测试仪的设计.pdf

现代科学仪器 第6期2009年12月 Modern Scientific Instruments No.6 Dec 2009 60 Modern Scientific Instruments No.6 Dec 2009 基于C8051F020的频率特性测试仪的设计 宋婀娜 丁淑艳 ( 黑龙江科技学院电气与信息工程学院 黑龙江哈尔滨 150027) 摘 要 采用新型单片机C8051F020 与高集成度DDS器件AD9851相结合,设计一种具有低成本、高测试精度的频率特性测试 仪。该测试仪器中,以C8051F020单片机为控制核心,实现了对被测网络频率特性的测量和数据的实时采集与处理;AD9851产生 扫频信号源,用模拟检波和数字鉴相的方法实现对被测网络幅频特性和相频特性的测量。实验与仿真结果表明,该系统不仅能 实现各种测试功能,而且具有较高的测试精度和较高的实用价值。 关键词 幅频特性;相频特性;测试仪;C8051F020单片机;AD9851 中图分类号 TB2 Design of Frequency-Characteristic Measuring-Testing Instrument Based on C8051F020 Microprocessor Song E’nuo,Ding Shuyan (College of Electrical Information Engineering, Heilongjiang Institute of Science and Technology, Harbin Heilongjiang 150027) Abstract In order to design a new frequency-characteristic measuring-testing instrument with low cost and high precision, C8051F020 MCU and AD9851 were adopted to realize the system. C8051F020 MCU was used to control core of the system which realizes the network measuring and real time data acquisition and processing. AD9851 was used for frequency sweep supply oscillator. The simulation detection and digital phase demodulation method were used to measure the amplitude frequency characteristic and the phase frequency characteristic of the network. Experimental and simulation results showed that the system not only realizes the functions, but also has high precision. Key words Amplitude Frequency Characteristic; Phase Frequency Characteristic; Measuring-Testing Instrument; C8051F020 MCU; AD9851 随着电子测试项目的不断增加和测试对象的 位检测电路。系统框图如图1所示。 逐渐复杂,测试速度和测量精度的要求也不断提高, 传统的测试方式和测试仪器逐渐不能适应形势的发 展。频率特性是一个网络性能最直观的反映,频率 特性测试仪广泛应用于电子工程等领域。传统的模 拟扫频仪大多是用LC电路构