A super-regenerative radio on plastic based on thin-film transistors and antennas on large flexible sheets for distributed communication links

Large-area electronics presents new form factors, enabling ubiquitous systems that are flexible and capable of scaling to very large areas. By processing thin-film transistors (TFTs) at low temperatures on plastic (using organics, amorphous silicon, metal oxides, etc.), blocks such as ADCs, amplifiers, and processors can be realized [1,2]; however, aside from short-range RFID tags [3], wireless links for long-range communication have not been achieved. A key challenge is that wireless systems typically depend on the ability to generate and operate at high frequencies, yet TFTs are limited to very low performance (f_t ∼1MHz). Specifically, the challenge is low device g_m, due to low mobility and limited gate-dielectric scalability, as well as high device capacitance, due to limited feature scalability and large overlaps for alignment margining on flexible substrates. This work presents a super-regenerative (SR) transceiver with integrated antenna on plastic that leverages the attribute of large area to create highquality passives; this enables resonant TFT circuits at high frequencies (near f _t) and allows for large antennas, maximizing the communication distance. The resulting carrier frequency is 900kHz, and the range is over 12m (at 2kb/s). As shown in Fig. 25.10.1, this will enable sheets with integrated arrays of radio frontends for distributing a large number of communication links over large areas.