Research On Several Key Technologies On Radiated Emission Testing In GTEM Cell

As a kind of EMC test sites, with the characteristics of low cost and wide frequency band and high testing efficiency and low demands of environment, GTEM cell has aroused a lot of concern by the international electromagnetic community. In the recent years, the research of basic theory and application of GTEM cell has been gradually developed, the application of GTEM cell has been expanded to some fields as antenna testing and RFID testing and RCS testing and system compatibility testing from the original field of electromagnetic compatibility testing. GTEM cell has become one of the mainly sites that can replace the anechoic chamber and open test aria. This paper depends on the following projects:the research of EUT's radiation characteristic and its compensation method (project Number:60971069); National 863 program:The research of RFID applications in the technology of communication testing (Project Number:2006AA04A106), and studies deeply in some critical problems existing in the processes of GTEM cell's applications, solves a numbered of problems that restrict the practical uses of GTEM cell. Finally this paper provides a theoretical basis for the new filed application of GTEM cell and its promotion.This paper uses the method of theoretical analysis, simulation modeling and experimental testing. The content covers the following aspects:the research on the TRP test using GTEM Cell, research on the directivity test of RFID tag in GTEM cell, the establishment of the relevant automatic test systems of GTEM cell, the simulation research on EUT radiation in GTEM cellThe main innovations of this paper are as follows:(1) It creatively proposes a method of testing a EUT's total radiated power using a GTEM cell, and develops a new field in the application of GTEM cell. As to the situation of the impact that GTEM cell has on the non-small-size EUT's radiated emission. It proposes the method of |S11| parameter compensation, further improves the testing precision of EUT's total power, expands the field of GTEM cell's application in radiated emission test. The related experimental result testifies the accuracy and efficiency of the testing method and parameter compensation, and can be used in practical test. This method makes a new field for GTEM cell's use, and |S11| parameter compensation method can effectively compensate the testing results, improves the aria of testing a EUT's total radiated power using a GTEM cell. At the same time, the method can also be used in the test of an antenna in GTEM cell.(2) In order to meet the current needs of RFID tag's test, this paper proposes a method of using GTEM cell doing the directional test of RFID tags. The expression of output power of GTEM cell is firstly given under the situation of RFID tag's radiated emission test. It provides a theoretical basis for the associated tests of RFID tags using GTEM cell. This method satisfies the needs of doing some RFID-related performance testing for the domestic manufacturers, also proposes a new application field for GTEM cell.(3) In order to further study the situation of EUT radiation emission in GTEM and the impact of GTEM cell and its test sites on the radiated emission testing result, the simulation model of the practical GTEM cell has been made. It shows the validity of the GTEM cell simulation model through a series of theoretical calculations and practical experiments. With the GTEM cell simulation model, some simulation analysis are made about the effects of the turntable in GTEM cell has on the EUT radiated emission testing and of the application of GTEM cell's output power formula. Some constructive conclusions have been made through the analysis of the simulation results.(4) Based on the method of the TRP test using GTEM Cell, an automatic test platform is set up for the RF testing of radio equipments in use in 2008 Beijing Olympic Games. It firstly put the method of using GTEM cell doing TRP test in the detection work of radio equipment in use, and was successfully applied in the detection work. It was applied to the testing work of radio equipments test in 2008 Beijing Olympic Games and achieved good effects. The automatic test platform is fully played the testing characteristics of GTEM cell in TRP test and the advantages of automatic test system, and solves the problem of testing the RF performance of EUT in use and proposes a new application field for GTEM cell.The paper does a deep research in some critical problems that GTEM cell has in its practical uses, also it provides some related research results for GTEM cell's practical use and its new application field.