Study On Amplitude Probability Distribution Measuring Method And Development Of APD Measuring System

As a statistical parametric measurement, APD method was acted as a standard electromagnetic disturbance measurement method in the latest version of international standards CISPR16-1 Ed.2-2006. The main task of this paper is to develop an APD meter that can fully meet the recommended requirements of CISPR indicators, and with independent intellectual property rights. An automatic test system platform for APD measurement would also be established. The BJTU_APD V1.0 meter and testing platform have already put into trail use at the National Radio Monitoring & Testing Center, and achieved the desired results. The study results of this paper fill the gaps in the domestic field.Firstly, a thorough review of APD method's development history was taken in Chapter 1, including its theory and applications, with regards to the characteristics of EMC. The author traces down the up-date development and the latest progress in this technology domain.In Chapter 2, based on circuit theory and statistical signal processing theory, the author deduced the EMI receiving devices' circuit response and the APD characteristics of the random signals which subject to typical probability distribution, and built the models for numerical simulation. The key specifications for APD measurement are also be discussed and determined in this chapter.Chapter 3 and 4 respectively introduced the BJTU_APD V1.0 meter's hardware and software system design.Chapter 5 gives the results of instrument calibration and validation.Innovation and creative points of this paper are as follows:1. Theoretical analysis and numerical simulation are taken, oriented to the circuit response of a typical receiver before its detector. A nonlinear simulation model of the general detector was established to illustrate the deficiencies of the detector-measuring methods (Chapter 2);2. Analyzed the APD characteristics of random signals with typical probability distributions, theoretically and numerically. And preliminary study with the noise modeling & fitting method was discussed. A pantograph-catenary impulse noise model was established to numerical simulate the electrified railway's RF disturbance (Chapter2); 3. Established the numerical relationship between sampling rate and uncertainty of APD measurement (Chapter 2);4. Successfully developed a general-purposed statistical parametric measurement hardware platforms, which is in the leading position in China (Chapter 3);5. Developed BJTU_APD V1.0 measuring meter in the hardware platform, the performance indicators have reached or superior to the requirements of CISPR. Formed IP core softwares with completely independent intellectual property rights (Chapter 4);6. A series of novel or original technologies was adopted in the hardware and software design, such as SIMO-FIFO architecture, efficient Double-Frequency APD processing units, dual-port RAM, long-period high-precision timers, standard serial bus interfaces, and etc. These technologies resolve the key technical problems such as processing speed and the busy waiting during measurement. They also provide the flexibility for inter-connect to different MCUs and system richness for the performance upgrading and extensions (Chapter 3,4);7. A complete APD test system platform has been set up. An automatic measuring system software WinAPD was developed, with a comprehensive measurement process control functions and user-friendly interface (Chapter 4).