A novel resonant tunneling delta-sigma A/D converter having no feedback loop for ultrahigh-speed operation

A resonant tunneling logic gate MOBILE is an ultrahigh-speed functional logic gate which switches at the rising edge of the clock. In this paper we describe a novel /spl Delta//spl sigma/ ADC having no feedback loop which make the best use of high-frequency performance of the RTD. The /spl Delta//spl sigma/ modulator use to convert the analog signal to the pulse density digital signal. This modulation technique suitable to MOBILEs using VCO were employed here. Testing the /spl Delta//spl sigma/ modulator concept using the MOBILE fabricated on the InP substrate concludes that the MOBILE works as an ideal 1-bit quantizer for high-speed ADCs.