Micromachined devices for impedance matching in automotive power line communications

In power line communication (PLC), the signals are carried and distributed by the wiring system. It is a promising technology which uses the existing system and has wide coverage; however, the impedances at the interface of the power line and the loads are not well defined. The mismatch in the impedances causes potentially high attenuation. This problem can be addressed by developing impedance matching circuit using tunable components based on micro-electromechanical systems (MEMS). In this thesis, the MEMS-based approach was investigated. The tunable inductors and capacitors were designed, fabricated and characterized. A microfabrication process was designed to realize thin membranes attach to the structural layer. The deflection was characterized for a range of actuating voltages. The tunable capacitors were employed in the matching network and tested. The test results were compared with the theoretical results and discussed. This thesis demonstrates the electrostatically actuated MEMS devices and matching network that can work in the PLC system. Furthermore, this thesis should serve as the groundwork for students who wish to design the impedance matching networks or who wish to fabricate electrostatically actuated MEMS devices with thin membranes of their own.