Efficient testing of RF MIMO transceivers used in WLAN applications

Multiple input multiple output (MIMO) systems that enable data transfer rates beyond 100Mbps for WLAN applications is under development and will emerge rapidly. While the higher data rates will enable numerous features in modern communication devices, the industry has to face the soaring test cost due to the increased test complexity and test time. Since MIMO systems have multiple RF paths, each path needs to be individually tested. Moreover, mismatch parameters among the multiple paths require synchronized sampling of RF signals, requiring complicated equipment. In this paper, we propose a low cost MIMO test solution that targets the specifications that are fundamental for MIMO operation, such as gain, IIP3, and phase imbalances between the RF paths. Our test methodology measures these parameters with a high accuracy while requiring only one RF frequency synthesizer. Using the proposed test method, RF MIMO systems can be tested using a mixed signal tester and a single fixed frequency RF signal generator.