3 GHz resonant tunneling clocked comparator

The combination of resonant tunneling diodes (RTDs) and heterostructure field-effect transistors (HFETs) provides a versatile technology for designing ultra-high-speed analog and digital circuits. Here we demonstrate an RTD-HFET comparator circuit that operates up to 3 GHz clock frequency. The RTD based comparator allows us to employ 75% fewer devices than all-transistor comparators. The circuit is measured to have a single-tone spur-free-dynamic range of at least 40 dB and a sensitivity of 5 mV at a 2 GHz clock.