Metamaterial-Enabled and Microwave Circuit Integrated Wearable Antennas for Off-Body Communications

This chapter presents two new types of recently developed wearable antennas. It presents the transformational designs for lightweight conformal wearable antennas which are highly efficient while, at the same time, having a compact footprint and a low profile in the MBAN band. These designs are enabled by placing a planar monopole antenna on top of an extremely truncated metasurface, which yields a front-to-back ratio in the radiation pattern that is remarkably high for its size and effectively isolates the antenna from the loading effects of the human body. The chapter focuses on compact, planar circularly polarized (CP) wearable filtennas with both narrow and wide operational bandwidths. It discusses the antenna design strategy, simulations, and experimental results, as well as on-body performance evaluations of these wearable antennas. Bandwidth broadening techniques are illustrated by introducing various interdigital capacitor loading schemes into the metasurface. The integrated band selective functionality of the radiating modules is verified by experimental measurements.