Research On Uncertainty Characteristic Of OTA Measurement System For Mobile Communication Terminals

People increasingly concern about the test of the comprehensive radiated performance inthe RF performance test for the mobile communication terminal products. This radiatedperformance reflects the final radiated RF power and receiver performance of the mobilecommunication terminals. The measurement for radiated RF power and receiver performanceof mobile stations over the air is necessary for testing and assessing the comprehensiveradiated performance of the mobile communication terminal products. With the rapiddevelopment of the OTA (Over the Air) measurement technology currently and especially thewidespread use of the2G and3G mobile communication, people put forward the higheraccuracy and reliability requirements for the OTA measurement data, which concretelyreflects the uncertainty of the OTA measurement system., Thus we need to do the research onuncertainty characteristic of OTA measurement system for mobile communication terminals.The reseaches in this thesis include following:1. We studied the developments of the OTA measurement technology and standard of theinternational and domestic mobile communication terminal products, and then weanalyzed the key technology of the OTA measurement by current advanced internationalstandards to make adequate preparations for the structure and research of themeasurement system.2. We obtained various factors that have effect on the uncertainty of the measurementsystem by the analysis of OTA measurement system, which are included in the rangereference, total radiated power and total isotropic sensitivity measurement, and provide atheoretical basis for the analysis of various components of the measurement system.3. We designed an anechoic chamber and various measurement equipments to make themeasurement system meet the measurement method for the radiated power and receiverperformance of OTA standards, which can carry out the OTA measurement for variousmobile communication terminal products. The OTA measurement system designed inthis thesis includes a RF shield anechoic chamber, multi-axis positioning system,measurement data collection and analysis software, measurement antenna,communication antenna, universal radio communications analyzer, spectrum analyzer,vector networ analyzer, switch/control system and so on. The measurement software cancomplete the test automatically by seting measurement template up after the integrationof various components, and generates2D and3D pictures.4. We analyzed the uncertainty characteristic of the complete OTA measurement system, and proposed a complete assessment method for the uncertainty characteristic. Wesubmitted an application for the CTIA (Cellular Telecommunications&InternetAssociation) Authorized Testing Laboratory, and performed the stability measurement toverify the performance of the measurement system during CTIA authentication.Finally, according to the uncertainty requirements of the measurement standard, themeasurement results by the assessment method for uncertainty characteristic that we proposedabove meet the measurement standard limit requirements well. There is a good stability forthe OTA measurement system. The OTA measurement laboratory in this thesis has beenauthorized by CTIA and becomes a CATL, which reflects the OTA measurement capabilitywith an international advanced level.