Omniscatter: extreme sensitivity mmwave backscattering using commodity fmcw radar

With the Internet of Things (IoT) anticipated to grow up to a trillion devices by 2035 [1] and 6G aiming at 10/m2 Massive Machine Type Communications [2], massive connectivity has long been considered a key to the success of IoT and diverse emerging services. Backscatter is an attractive option for scalability, operating at tens of µW [3] by reflecting the wireless signal without generating the power-hungry passband signal itself. The ultra-low power operation of backscatter offers long-term sustainability. In particular, recent advances in mmWave backscatters [4,5,6] present a great potential for scalability by exploiting the abundant spectrum resource in the mmWave ranging up to 14 GHz (60 GHz band); a bandwidth over two orders of magnitude greater than 26 MHz and 100 MHz in the popular 900 MHz and 2.4 GHz bands, respectively.