The analysis of EMI noise coupling mechanism for GPS reception performance degradation from SSD/USB module

Due to increasingly wide spreading applications of location-based services (LBS), a variety of portable devices are equipped with GPS module for navigation. If a notebook or ultrabook computer is embedded with a built-in GPS antenna and module, the EMI noise generated from SSD (Solid State Drive)/USB 3.0 module of the PC will radiate to affect the receiving performance of GPS antenna. We have found that even if the SSD module locates far away (about 60 cm) from the GPS antenna, the positioning accuracy and performance is still affected. Not to mention that ever shrinking space for components placement will bring GPS antenna and noisy digital devices much closer, and thus further degrades the position and navigation performance Since the receiving sensitivity of GPS system is the critical parameter for successful LBS applications this study investigates the technique to evaluate the level of EMI noise from nearby SSD/USB 3.0 and provides the adequate analysis for application and integration of SSD/USB 3.0 with GPS for ultrabook or traditional notebook PC. To analyze the EMI effect on GPS performance we have categorized the coupling mechanism between SSD/USB 3.0 and GPS RF modules into antenna coupling and circuitry coupling With the utilization of platform noise scanner on closely located GPS and noisy digital modules in this study, we can analyze and identify the root cause for receiving sensitivity degradation with compact form design limitation. We will also evaluate the noise limit for platform noise of GPS applications, and hope to further apply IEC 61967 IC-EMI measurement techniques on the component level to solve the problem of system integration and improve the performance in the future study.