3.48 ps ECL ring oscillator using over-300 GHz f T / f max InP DHBTs

Abstract
An ECL gate delay of 3.48 ps/stage in a 19-stage conventional ring oscillator fabricated in an over-300 GHz fT/fmax InP DHBT technology has been demonstrated. This is the first report (to the authors' knowledge) of sub-4 ps ECL gate delay. Large collector current density contributes to the very short gate delay.