A Novel Dual-band and Bidirectional Nonlinear RFID Transponder Circuitry

This work presents the first bidirectional circuitry for Internet of Things (IoT) transponder that simultaneously generates harmonics and subharmonics, dual band frequencies. A multi-band or wideband localization system is essential for future wireless sensor network to mitigate the influence of multipath signals and interferences for indoor environment. The proposed frequency generation circuitry is based on novel nonlinear ring resonator (NRR) which is a standing wave resonator generating two sustainable resonant frequencies based on the periodic nonlinear unit-cell in a ring configuration. The NRR circuit consumes zero DC power and has 10 dB conversion loss at $f_{in}$ of 4.8 GHz with 120 MHz bandwidth in subharmonic, divider mode, and 16 dB loss in harmonic at $f_{in}$ of 2.4 GHz, doubler mode.