Oscillators Utilizing Ferroelectric-Based Transistors and Their Coupled Dynamics

We propose the application of ferroelectric (FE)-based transistors, viz., negative capacitance FET (NCFET) and Hysteretic ferroelectric FET (FEFET) in the design of coupled oscillators. The proposed oscillator utilizes hysteretic inverter voltage transfer characteristics, which is achieved by virtue of: 1) negative output conductance (NOC) in NCFETs and 2) hysteretic transfer characteristics in FEFETs. With the aid of output-To-input feedback in the inverter, we show sustained oscillations which are controllable by the gate voltage of the feedback transistor ( {V} -{\mathrm {BIAS}} ). With focus on NCFET-based designs, we show that feedback implementation with pass transistor (PT) and transmission gate (TG) yields relaxation and sinusoid-like characteristics, respectively. Such behavior offers promises for dynamically reconfiguring the oscillator dynamics. We report the fundamental frequency ( {f} ) in the range of 12 MHz-800 MHz and 0.7 MHz-417 MHz for TG and PT implementations, respectively. We discuss how this approach can be extended to hysteretic FEFET-based designs. We also analyze coupling between two oscillators considering various strengths of coupling capacitance ( {C} -{\mathrm {CP}} ). We establish the conditions for synchronization of {f} between the two oscillators with respect to difference in {f} and {C} -{\mathrm {CP}}.