Broadband THz Detection Using InP Triple-Barrier Resonant Tunneling Diode With Integrated Antenna

A broadband THz detector consisting of a triple-barrier InP Resonant Tunneling Diode (RTD) with a monolithically integrated circularly polarized spiral antenna is designed, fabricated, and measured at room temperature. A free space measurement setup is utilized for far-field characterization. The detector (evaluated at zero-bias) is illuminated by a chopped continuous wave signal in the 220-330 GHz band, and the direct detection scheme consists of a lock-in amplifier in voltage mode readout. The measured average responsivity RV is in the range of 750 V/W with a peak of 900 V/W at 257.5 GHz, with the lowest calculated NEP of 2.5 pW/√Hz.