Antenna Design Methodology for Remote Keyless Entry: The Effects of the Human Body and Vehicular Antenna Positions on Coverage 2019-01-1058
In this era of technologies, Remote Keyless Entry (RKE) system has become an integral part of motor vehicles. Over the years, a lot of functionalities have been added to RKE systems. To achieve desired performances of such systems, the key-fobs are expected to be operational in close proximity of human body. However, as human bodies are very lossy dielectric structure, they are expected to have impacts on antenna behaviors. Not only that, the antenna characteristics are likely to be varied depending on the body parts the key-fob is in the vicinity of. Also, the functionality of such systems requires placement of receiving antennas on the vehicle. Mounting receiving antennas on a vehicle’s body changes its performance characteristics and variations are also highly anticipated for changing the placement position as well. Taking these variations into account during the antenna development phase become expensive and tedious since achieving a functional design would require several iterations, testing, and modification, in the design. Hence, Computational Electromagnetic (CEM) techniques become a feasible solution to explore the effects of antennas’ placements and adopt necessary modifications as needed. This paper introduces a methodological process of designing RKE antennas using 3D CEM Simulation tool; namely Altair FEKO. Moreover, the presented methodology includes an analysis of variations of remote keyless entry system’s radiation characteristics while placed in the vicinity of different human body parts. The effects of the vehicular receiving antenna position on the RKE system’s coverage are also investigated and analyzed. This paper studies the RKE system’s performance not only at 315 MHz but also at 433.92MHz for universal vehicle usages. At the different step of the methodological process, the appropriate CEM method is used and explained. The full-wave CEM methods are used even when the whole vehicle and human body are included.