Emerging millimeter-wave applications require the development of suitable low-noise oscillators for use as local oscillators (LOs) in receivers. To answer that call, researchers Munkyo Seo, Miguel Urteaga, Jonathan Hacker, Adam Young, Zach Griffith, Vibhor Jain, Richard Pierson, Petra Rowell, Anders Skalare, Alejandro Peralta, Robert Lin, David Pukala, and Mark Rodwell combined forces from Teledyne Scientific Co., the University of California at Santa Barbara, and the California Institute of Technology's Jet Propulsion Laboratory (JPL)creating a quarter-micron indium-phosphide (InP) heterojunction-bipolar-transistor (HBT) integrated-circuit (IC) technology capable of fabricating fundamental-frequency oscillators through 0.57 THz. The oscillators feature transistors with extrapolated maximum frequency of oscillation exceeding 800 GHz, using a full IC process.

To demonstrate the capabilities of the process, the researchers fabricated a series of fundamental-frequency oscillators using a differential series-tuned topology followed by a common-based buffer amplifier. Sources with tuning bandwidths as wide as 300 GHz were developed and characterized. See "InP HBT IC Technology for Terahertz Frequencies: Fundamental Oscillators Up To 0.57 THz," IEEE Journal of Solid-State Circuits, October 2011, p. 2203.