Study of Radiated Emission from Wireless Positioning System and the Strategies to Minimize the Radiations

The objective of this research work is to develop Wireless Positioning System compatible with CISPR EMI/EMC standard. The system should work satisfactorily under dynamic and environmental conditions related to automotive platforms. This paper presents the measurement of Radiated Emission from GPS based Wireless Positioning/Localization System. It also deals with the implementation of the shielding techniques in order to make the system compatible with the EMC requirements as per CISPR EMI/EMC Standard. In the current scenario, the GPS based Wireless Positioning System is an essential part in the application areas such as logistics, public transports, naval ships, railways and stringent environment like defense vehicles. Due to its usefulness in daily life, the system has been considered as the test model for this research work. The reliability prediction for the model has been done with MTBF and Failure Rate estimations. The Radiated Emission level has been investigated for GPS based Vehicle Positioning System at the Centre for Electronics Test Engineering, Pune, India and Automotive Research Association of India (ARAI), Pune, India. This model was first validated in the GTEM Cell and further it was tested in the EMI chamber. It has been observed that RE level at certain frequency bands was found to be exceeding the specified limits as per the EMC standard. In this paper, few innovative techniques like shielding with enclosures has been proposed and implemented to reduce the level of radiated emission. The shielding enclosure of aluminum and copper were designed and implemented. Also, simulation of the stress level has been done for the copper enclosure with ANSYS software. The results of re-validating the GPS based system with aluminum and copper enclosures are presented here. After re-validation, radiated emission level was found to be reduced by around 10–40 dB making the system compatible with the EMI/EMC CISPR standards.