New circuits have been designed and fabricated with operating frequencies over 325 GHz. In order to measure S-parameters of these circuits, an extensive process of wafer dicing and packaging, and waveguide transition design, fabrication, and packaging would be required. This is a costly and time-consuming process before the circuit can be tested in waveguide. The new probes and calibration procedures will simplify the testing process.

New on-wafer probes, and a procedure for their calibration, have been developed that allow fast and inexpensive S-parameter characterization of circuits in the 325-508-GHz frequency band. The on-wafer probes transition from rectangular waveguide to coplanar waveguide probe tips with 40-μm nominal signal-to-ground pin pitch so as to allow for probing circuits on a wafer. The probes with bias tees have been optimized for minimal insertion

loss and maximum return loss when placed on 50-ohm structures to allow for calibration. The calibration process has been developed using the Thru-Reflect-Line Agilent algorithm with JPL determined calibration structures and calibration coefficients for the algorithm.

This new test capability is presently unique to JPL. With it, researchers will be able to better develop circuits such as low-noise amplifiers, power amplifiers, multipliers, and mixers for heterodyne receivers in the 325-508-GHz frequency band for remote sensing/spectroscopy.

This work was done by King Man Fung, Lorene A. Samoska, David M. Pukala, Douglas E. Dawson, Pekka P. Kangaslahti, Todd C. Gaier, and Charles Lawrence of Caltech; Greg Boll of GGB Industries Inc.; and Richard Lai and Xiaobing Mei of NGC for NASA’s Jet Propulsion Laboratory. For more information, contact This email address is being protected from spambots. You need JavaScript enabled to view it.. NPO-47575