645-GHz InP heterojunction bipolar transistor harmonic oscillator

Abstract

645-GHz signal generation with a harmonic oscillator based on a 250-nm InP heterojunction bipolar transistor technology is demonstrated. The oscillator is based on the common-base cross-coupled topology, generating a second harmonic signal through the push-push operation. The fabricated oscillator exhibits oscillation frequencies ranging from 561.5 to 645.1 GHz with bias variation. The measured peak output power is -17.4 dBm with a dc power dissipation of 49.3 mW (dc-to-RF efficiency of 0.04%). Additionally, terahertz imaging was successfully demonstrated with the developed oscillator employed as a signal source.