Single-Antenna Backscattered BLE5 Transmitter with up to 97m Range, 10.6 μW Peak Power for Purely-Harvested Green Systems

This paper introduces a backscattered BLE5 transmitter for low-cost single-antenna green systems solely powered by mm-scale harvesters. Peak power reduction to 10.6 $\mu \mathrm{W}$ is achieved while enabling BLE-compliant spectral mask up to the maximum allowed backscattered power for range extension. Peak power is reduced via an approximate GFSK modulator architecture based on a non-uniform self-sampling digitally controlled oscillator (DCO) with period pruning/clustering, in place of a power-hungry Gaussian filter and PLL used in conventional GFSK modulators. A 180-nm testchip shows 97-m range with commodity receiver at 4X power and 3X range improvement with respect to prior art.