A group at UCLA, in collaboration with the Jet Propulsion Laboratory, has designed a voltage-controlled oscillator (VCO) created specifically for a compact, integrated, electronically tunable frequency generator useable for submillimeter-wave science instruments operating in extreme cold environments. The VCO makes use of SiGe heterojunction bipolar transistors (HBTs). The SiGe HBTs have a 0.13-micrometer emitter width. A differential design was used with two VCOs connected to form a quadrature signal. A 2.5-V supply is required to power the circuit. A cross-coupled CMOS pair is used for emitter-degeneration of the SiGe HBTs, and the design uses coupled load and base inductors. The circuit oscillates at 105 GHz. A linear superposition of VCOs has been designed to achieve four times the oscillation frequency of the fundamental oscillator.
This work was done by Alden Wong, Tim Larocca, and M. Frank Chang of UCLA , and Lorene A. Samoska of Caltech for NASA’s Jet Propulsion Laboratory. For more information, download the Technical Support Package (free white paper) at www.techbriefs.com/tsp under the Electronics/Computers category. NPO-47116