Backscattering communication is a key feature that will enable the true IoT/5G revolution towards massive use. However, the specification pressure it puts on the reader/gateway is a major drag on their deployment. In fact, self-jamming resulting from backscattering operation is highly problematic. Harmonic Backscattering Communication comes as a great solution to improve the dynamic range of the backscattered signal that can be received/analysed, thus increasing communication distance. We propose here a harmonic backscattering front-end based on nonlinear negative resistance device that also operates like usual backscatter tag with legacy reader. The circuit provides above +20dB conversion gain and reflection gain, and operates with a supply voltage below 200mV, which is a critical improvement over transistor technology