Uncertainty Analysis Of Radio Equipment RF Conformance Automatic Test System

Uncertainty principle is the essence of nature. Found measurement uncertainty is an important aspect of the modern theory of error. In order to overcome the existing problems of error evaluation and to express the measurement result more scientifically, from 1993, International Bureau of Weights & Measures issued the "Guide to the Expression of Uncertainty in Measurement, (GUM)". In accordance with international standards, China has developed its uncertainty norm JJF1059-1999 "Uncertainty of Measurement Evaluation". Since then assessed by measurement uncertainty has become the main method that is widely used in calibration, testing, evaluation, and other aspects.As the fast development of computer technology, electronic technology, and communications technology, testing technology has also been developed rapidly. The testing processes become more efficient, simple and flexible under the control of computer. In the communications field, the trend that automatic test system as a mainstream means of testing has become increasingly evident. Through automated testing software, we can control more than one instrument.The automatic test system would complete complicated and tedious work of test, and avoid errors caused by human factors. At present, radio equipment RF performance approval tests, such as FM walkie-talkie devices, PHS, DECT, GSM, CDMA, WCDMA, bluetooth, WLAN, are completed by the automatic test system.As a measurement tool, automatic test system has its system uncertainy, and this uncertainty would produce non-negligible impact to the measurement result. However, uncertainty research in electromagnetic compatibility start late in China. Especially in radio measurement, the evaluation of measurement uncertainty has its own characteristics. Even given the same parameters, the standard uncertainty and the combined uncertainty will be different, because of the different interpretations of uncertainty assessed meathod, and will lead to the results of being incapable to make determination that wether the measurements comply with standard or not. At present, the relevant domestic standards in this area hawe not yet introduced. This article will introduce uncertainty principle into measurement system, discussed the actual measurement system model.Through the understanding of the ETSI technical reports, and other related documents,this article will give measurement uncertainty evaluation process in the radio measurement in detail for the relevant reference.This paper adopts the research meathod of from the whole to part, from general to specific. Firstly, summarize the domestic and international research and enabling progress in measurement uncertainty. Then start from the basic theory, give a brief introduction to the basic concepts of uncertainty, methods of evaluation processes, and automatic test system's basic structure and principles, build the theoretical foundation for the follow-up research and analysis. Thirdly, in accordance with the aforementioned theory, the article will give the uncertainty mathematical models and approach of the RF conducted automatic test system. Various impact factors can be identified accurately, comprehensively by using these models. The simplified method in dealing with the mismatch Uncertainty will make the uncertainty analysis and calculation become simple and feasible. Subsequently, choose GSM Terminals RF Automatic Test System for instance, computing system uncertainty, and giving uncertainty report. Finally, according to the analysis of the report, the article will give some effective proposals to reduce the uncertainty of Automatic Test System.