Wearable Electrically Small Loop Antennas for Monitoring Joint Kinematics: Guidelines for Optimal Frequency Selection

We have recently reported a new class of wearable electrically small loop antennas (ESLAs) that can seamlessly monitor joint kinematics (i.e., flexion and rotation). In this paper, we aim to provide generic guidelines for optimally selecting the operating frequency of such designs. Key to our approach is to first establish crucial performance benchmark criteria (i.e., received power level, angular resolution, and effect of tissue dielectric property variation). The frequency range we consider spans from the antenna mode of operation to the electrically small antenna mode (24 MHz to 1028 MHz chosen here). Based on the frequency-specific tradeoffs for each of the aforementioned performance benchmark criterion, a suitable optimal operating frequency is eventually selected (34 MHz identified as optimal in our example demonstration).