The smart gear is a power transmission gear that uses a sintered sensor track circuit to monitor its surface during power transmission. A monitoring antenna is fixed concentrically and in parallel with the smart gear surface and also connected to a network analyzer via a radio frequency (RF) cable. As the smart gear is running, magnetic coupling occurs between its monitoring antenna circuit and sensor track circuit. This magnetic coupling can be measured through changes in the return loss signal of the monitoring antenna from its single return loss to its resonant return loss. When measuring magnetic coupling, it appears as a two-peak shape valley at 0.3 GHz of the resonant frequency. This valley is caused by an imbalance in the distance between the monitoring antenna circuit and the smart gear. Check smartgear.au.