Solar-powered spike-based communication system with analog back scatter

Radio frequency backscatter involves the modulation of antenna load with the message signal. The information content of the message signal appears in the amplitude of the reflected signal from the antenna. The message can either be a digital signal or an analog signal. The former results in a digital backscatter communication while the latter results in an analog backscatter communication. In this paper, the analog backscatter using multiple time-spaced spike signals, which carry information of its identification and the sensor in their time separations is presented. A solar-cell powered spike generation circuit is designed and delay elements are used with the spike generator to encode the information of the identification and sensor. An HSMS2852 small signal Schottky diode is used for analog spike backscattering. A two coupler based RF cancellation technique is implemented to reduce the interference for the proposed full duplex communication system. A time-frequency analysis of the spikes carrying sensor and ID information is performed.