ABSTRACT
MOBILE was 2 GHz. Vdd and v •• are 1.4 V and -1.3 V, respectively. The waveforms are inverted by the open-drain buffer Tr6. The output signals are random pulse sequences, and the pulse density is visible in the plot density of the traces. The density of the "I" pulses decreased, as the input voltage decreased from (a) to (d) in order. Figure 6 shows the measured de component of the output current, which corresponds to output pulse density, as a function of the input voltage. This figure clearly indicates that the circuit converted the input voltage to the output pulse density. An extremely high clock frequency higher than 100 GHz should be possible by reducing the gate length of the HEMTs to 0.1 J.Uil and optimizing the circuit parameters.
