Effect of phase fluctuation and distance of smart gear on return loss of receiver antenna

抄録

The research concentrates on evaluating the impact of phase fluctuation and distant effect between two antennas in our developing "smart gear health monitoring system" using directly printed crack detection sensors on gear technique. Due to the importance of the magnetic resonant signal occurring when these two antennas are paired to the crack detection quality of our technology, the consideration of these effects, hence, is essential. The study has employed both theoretical simulation and experimental work for validation of the results. For simulation result, a Multiphysics simulation environment, namely COMSOL Multiphysics version 5.4 is used for evaluation while for experimental results, a developed laser sintering technology of conductive ink (NPS-J Harima) is utilized to print a pattern of designed open spiral antenna on polyacetal (POM) plates with polyimide layers covered on their surfaces. In the case of the phase fluctuation consideration, the relative phase angle of two antennas is selected from 0 to 360 degrees with an increment of 15 degrees and in case of distant effect, the relative distance is selected in the range of 0 mm to 4.9 mm with increment of 0.1 mm. By scrutinizing and comparing the achieved results, it shows that the experimental results approximately agree with the simulation results. Consequently, the phase fluctuation and relative distance have undoubtedly influenced to the physical electromagnetic resonant coupling formed between this smart gear antenna and its monitoring antenna. Since the phase fluctuation will always occur when two rotating antennas are placed in parallel, closely and concentrically, these recognitions certainly play an essential role in the accuracy of our frequency analysis procedure for parameter identification of the system in the near future.