Metasurface-Inspired Maintenance-Free IoT Tags Characterised in Both Frequency and Time Domains

We present metasurface-inspired maintenance-free IoT tags that can be characterised not only by frequency-domain profiles but also by time-domain profiles. In particular, time-domain characterisation is made possible by implementing the waveform-selective mechanisms of recently developed circuit-based metasurfaces that behave differently, even at the same frequency, in accordance with the pulse duration of the incident wave. Our designs are numerically and experimentally validated and potentially contribute to accommodating an increasing number of IoT tags within a single wireless network while reducing maintenance effort.