| With the rapid development of SATA, PCI, Express, USB3.0 and other high speed serial communication technology, differential transmission lines in modern electronic industry has been very widely used, high speed, high frequency, high density has become an important trend in the development of electronic technology, University of Electronic Science and technology in the past few years has independently developed the characteristic impedance tester TDR ZK-2010, sampling bandwidth only 5GHz, TDR bandwidth is only 1.75 GHz, can not meet the flexible plate, plate impedance measuring 2, 3cm length, and the algorithm pseudo difference divided by technology in some cases of inaccurate measurement, and will reduce the performance of TDR.The purpose of this research is to the past years of software design technology and experience and Tektronix real differential TDR instrument combines R & D, 12 GHz bandwidth(20GHz sampling bandwidth) of high performance TDR truly differential characteristic impedance analyzer, and its purpose is to research platform truly differential technology to Tektronix instrument, real difference technology research and the software development, and lay the foundation for the subsequent development of 10~20GHz sampling bandwidth TDR instrument.This paper first analyzes the single end impedance test technology and the real difference, Pseudo differential algorithm, Pseudo differential three difference technology differences, then put forward the overall design scheme of the instrument and equipment standard I/O interface software control technology based on VISA, and analyses the software design requirements from the two aspects of function and performance. Then according to the overall scheme and the overall structure of software design method of object oriented programming, the software modules.Next, the true difference calibration and testing technology of characteristic impedance are analyzed and the related research, summed up the calibration process and the detailed design, the module of the software for the detailed design and implementation, focus on the main control program for setting and synchronized sampling oscilloscope, realize the parameter configuration module, multi thread allocation, design the data transmission module, data processing module, and the calibration process and the realization of algorithm.Finally, from the function, performance and test results of the three aspects of the design of the software for the detailed test, proved that the system can meet the real difference characteristic impedance test requirements; also prospects for the development of the industry and the further research work is prospected. |
