High-Speed Digital Circuits Using InP-based Resonant Tunneling Diode and High Electron Mobility Transistor Heterostructure

Resonant tunneling diodes (RTDs) exhibit a negative-differential-resistance (NDR) characteristic and a picosecond-level switching time (1.5 ps). The NDR characteristic provides the possibility of reducing circuit complexity and power consumption. The RTD's very fast switching characteristic provides the possibility of high-speed operation. Utilizing the RTD's characteristics, we designed and fabricated high-speed implementations of a static inverter, a three-stage ring oscillator, and basic Boolean logic gates. Using these results, we designed a 2-bit analog-to-digital converter (ADC) with reduced circuit complexity. Spice simulation proved that the designed ADC can operate at a sampling frequency of up to 10 GHz.