Broadband THz spectroscopic imaging based on a fully-integrated 4×2 Digital-to-Impulse radiating array with a full-spectrum of 0.03–1.03THz in silicon

This paper presents a broadband THz frequency-comb spectroscopic imager based on a fully-integrated 4×2 picosecond Direct Digital-to-Impulse (D2I) radiating array. By employing a novel trigger-based beamforming architecture, the chip performs coherent spatial combining of broadband radiated pulses and achieves an SNR>1 BW of 1.03THz (at the receiver) with a pulse peak EIRP of 30dBm. Time-domain radiation is characterized using a fsec-laser-based THz sampler and a pulse width of 5.4ps is measured. Spectroscopic imaging of metal, plastic, and cellulose capsules (empty and filled) are demonstrated. This chip achieves signal generation with an available full-spectrum of 0.03-1.03THz. The 8-element single-chip array is fabricated in a 90nm SiGe BiCMOS process.