Simulation of Inverted F-type Antenna Arrays for Evaluation of Bluetooth Connectivity between a wBMU and wCMUs for Electric Vehicles

According to the 2020 report from Global Electric Vehicle Outlook [1], it is estimated that by 2030, almost 30 % of all new vehicle fleet will be based on electric propulsion. Thus, there is an imperious need to push forward the technical improvements in the E-mobility domain. As presented in [2], there are several important gains obtained, by shifting from a dedicated wired communication protocol to a wireless antenna-based system, with regards to battery monitoring. They are represented by the exclusion of cables and connectors so that the bill of materials can be reduced, as fewer components are needed; the increase of energy density by reducing the space required for cables & connectors; the flexibility in adaptation of modules and the diminishing of recall/ repair time intervals as fewer cable connections are present in the battery pack. The following paper aims to present a methodology for investigating the operation of antenna arrays incorporated in an EV battery pack. The possible challenges when it comes to integrating a wireless communication system within a Battery Management Unit (BMU) stand for the potential disturbances to the wireless network from external electro-magnetic sources. The Cell Monitoring Circuits (CMUs) will be used for monitoring the electric and thermal parameters of the battery cells for a non-commercial battery pack. An investigation is highlighted regarding the electromagnetic coupling efficiency of Inverted F-type Antennas (IFAs) used for both the BMU and CMU modules. Starting from a general IFA topology, the antenna scattering parameters, radiation efficiency and matching circuit will be computed by using a three-dimensional FEM simulation tool. The calculus will be performed in order to simulate the operating conditions for a frequency bandwidth of 2.4 up to 2.4835 GHz. A frequency sweep will be carried out to evaluate how the IFAs behave outside the desired frequency spectrum. Simulations will be carried out to highlight the behavior at both a component level for the master and slave radio-frequency units, but also at a system level for multiple modules placed in a battery pack enclosed by a metal housing.