Alternatif akım elektrikli araç şarj cihazlarında lte/5g hücresel haberleşmenin kararlılığını sağlamak amacıyla havadan anten performansının iyileştirilmesi

This thesis aims to ensure robust cellular connectivity for alternating current electric vehicle (AC EV) chargers by implementing reliable communication protocols and optimizing antenna performance. Key performance metrics, such as Total Radiated Power (TRP) and Total Isotropic Sensitivity (TIS), are used to assess connectivity between the cellular module, antennas, and the base station. Root-cause analyses identify the factors degrading antenna performance, while theoretical evaluations support the proposed design improvements. The results offer a framework to enhance connectivity, ensuring remote control of AC EV chargers as mandated by the Open Charge Point Protocol. The proposed methodology is validated on two AC EV charger platforms. For the EVC01 platform, low band Long Term Evolution (LTE) degradation is shown to result from near-field interaction between the antenna and Printed Circuit Board (PCB), together with conducted interference components. Restructuring the PCB layout and applying a common mode filter improves LTE Band 8 TIS by approximately 6 dBm. For the EVC08 platform, the dominant issue is near-field coupling induced by the internal panel structure, and suppressing resonance through a dual-point grounding approach improves LTE Band 8 TRP by approximately 6 dBm. Furthermore, for 5G New Radio (NR) Frequency Range 1 (FR1) operation on the EVC08 platform, optimized antenna placement and proper port–band mapping yield approximately 17 dBm improvement in TIS for the n5, n20, and n28 bands, ensuring stable connectivity across all tested channels. This thesis establishes a physically consistent and experimentally validated framework to improve LTE/5G NR FR1 cellular communication performance in AC EV chargers.