A 220 V/W, 25 pW/√Hz NEP bow-tie antenna-coupled pHEMT detector at 250 GHz

This paper presents a high responsivity THz detector formed of two depletion mode pseudomorphic high electron mobility transistors (D-pHEMT) coupled to an on-chip bowtie antenna in GaAs 130 nm technology. The measured absolute responsivity of the integrated detector is 10 V/W at 250 GHz at a gate bias voltage of -0.3 V. A silicon lens attached to the GaAs substrate improves the responsivity of the detector by 20X while showing a noise equivalent power (NEP) of 25 pW/√Hz.