Ultrafast electronic devices with fundamental operating frequencies above 100 GHz are used in a wide variety of applications—examples include radio astronomy, climate monitoring, mm-wave imaging, and high-speed wireless data relays. The main method for testing the components of these devices is to make physical contact to the devices using micro probes. This approach has three main limitations: (1) each time the probes are landed on a device, they damage the metal contacts of the probe landing site, limiting the number of contact cycles that can be made; (2) the micron-scale positioning error is on the order of the guided wavelength in the devices, adding uncertainty to measurements of the phase of transmitted or reflected signals; and (3) spurious modes of electromagnetic wave propagation are easily excited near the probe contacts, reducing measurement accuracy. One alternative to physically landing probes is to perform quasi-optical wireless probing. In quasi-optical wireless probing, collimated beams of mm-wave radiation are coupled in and out of a device under test using planar antennas that are integrated into the device. This potentially eliminates many of the limitations of physical wafer probing. However, quasi-optical probing has not been extensively studied, so there are still many open questions about its limitations. In this research opportunity, the successful candidate will address these questions through design, simulation, fabrication, and measurement of high-frequency calibration standards in the frequency range from 100 GHz to 1 THz using both conventional wafer-probing techniques and quasi-optical probing.

 

References

Caglayan C, Trichopoulos GC, Sertel K: "Non-contact probes for on-wafer characterization of sub-millimeter-wave devices and integrated circuits." IEEE Transactions on Microwave Theory and Techniques 62.11: 2791-2801, 2014

Williams DF, et al: "Crosstalk Corrections for coplanar-waveguide scattering-parameter calibrations." IEEE Transactions on Microwave Theory and Techniques 8.62: 1748-1761, 2014

 

key words

Quasi-optical; Microwave; mm-wave; On-chip; Metrology; Wireless; MMIC; Broadband; Microfabrication;

Citizenship:  Open to U.S. citizens

Level:  Open to Postdoctoral applicants