A Terahertz Detector Array in a SiGe HBT Technology Richard Al Hadi ,S t u d e n tM e m b e r ,I E E E, Janusz Grzyb, Bernd Heinemann, and Ullrich R. Pfeiffer , Senior Member , IEEE

Abstract

This paper presents HBT terahertz power detectors implemented in an experimental 0.25- m SiGe process technology with a peak of 280/435 GHz. Based on the nonlinearity of the HBT base-emitter junction, the detector operates as a square-law down converter , mixing terahertz frequencies directly to dc. Fifteen detectors have been arranged in a 3 5-pixel array with differential on-chip ring antennas. The array has been assembled with a hyper-hemisphe rical silicon lens. Referred to the collecting aperture of the lens, a maximum optical current responsivity of 1 A/W and a minimum noise equivalent power (NEP) of about 50 pW have been measured at 0.7 THz with a 125-kHz chopping freque ncy. The detectors have been characterized from 0.65 to 1 THz.