Resonance-Enhanced Coupling for Range Extension of Electromagnetic Tracking Systems

This paper investigates the use of resonance-enhanced coupling to increase the received signal level in a six-degree-of-freedom electromagnetic tracking system. Resonant coupling is found to increase the efficiency of the transmitter and increase the gain of the sensing coil, resulting in improved range. However, the measurement update rate is reduced due to the settling time of the transmitter circuit and the limited bandwidth of the sensing circuit. A resistive tuning approach is proposed to balance the tradeoff between a decreased measurement bandwidth and an improved signal level.