Plenary Talks
Terahertz Imaging with CMOS/BiCMOS Process Technologies
Dr. Ullrich Pfeiffer
University of Wuppertal
Recent advancements in silicon process technologies have made it possible to integrate active and passive devices with cut-off frequencies penetrating the mmWave and near Terahertz region. Currently, technologists target cut-off frequencies beyond 0.5 THz, while silicon integrated passive Schottky Barrier Diodes (SBD) have shown cutoff frequencies above 1 THz.
Specifically the realization of efficient THz detection systems has spurred increased interest in applications such as imaging, spectroscopy, chemical/biologic identification, hidden object detection, and communication with ultra-high data-rates.
The push in frequency imposes a number of challenges for the design of mmWave and THz circuits in silicon. Challenges are to mitigate the roll-off of characteristic circuit parameters like minimum noise-figure (NF), linearity, phase-noise, conversion gain, maximum output power and efficiency. The talk will describe recent attempts to overcome such limitations based on CMOS and BiCMOS process technologies. In particular, the talk will present a Non-Quasi- Static (NQS) device modeling approach, which has led to the design of the first monotonically integrated 0.65 THz CMOS focal-plane array including antennas and amplifiers for the detection of radiation above the device cut- off frequency. The response to terahertz radiation can be understood as a distributed effect based on resistive self-mixing inside of the two- dimensional FET channel. Additionally, 0.65 THz results of sub-harmonically pumped SiGe HBT mixers will be presented, which in summary, show the potential of silicon for future THz imaging applications.