Michael Hrobak

Flip-Chip Interconnects for 250 GHz Modules

With the increasing availability of MMICs at frequencies beyond 100 GHz low-loss interconnects for module fabrication in this frequency range become essential. This letter presents results on a flip-chip mounting approach exhibiting a bandwidth of more than 250 GHz, supporting both coplanar and stripline transitions. The interconnects are realized with 10 μm-diameter AuSn microbumps. S-parameter measurements show an insertion loss of less than 1.0 dB per interconnect and a return loss better than 10 dB up to 250 GHz. The experimental results are in good agreement with 3-D EM simulations.

MOS-16: A new method for in-fixture calibration and fixture characterization

The calibration of test fixtures or the estimation of their performance are well known tasks. In the case of fixtures with variable length, there are some established methods to de-embed the DUT (Device Under Test). The calibration or evaluation of a fixture with a fixed length, like a socket or a probe-card offers less possibilities. This contribution presents a novel calibration procedure, capable of gathering not only the information required for a proper de-embedding but also for an absolute characterization of fixed length fixtures, including crosstalk. In order to achieve this, specific assumptions have to be made. These assumptions, the resulting calibration scheme as well as a first validation through a known device will be addressed together with a first discussion on error propagation.

Manufacturable Low-Cost Flip-Chip Mounting Technology for 300–500-GHz Assemblies

We developed a chip mounting technology suitable for low-cost assemblies in the 300–500-GHz frequency range, compatible with standard chip and submount fabrication techniques. The waveguide and transition designs are compatible with indium phosphide heterobipolar transistor millimeter-wave monolithic integrated circuit chip architecture. Increased conductor shielding in different multilayer thin-film waveguide topologies is applied to suppress radiative losses, enabling low-loss interconnects up to 500-GHz bandwidth. Standard flip-chip align-and-place equipment is used to assemble the chips onto submounts. Losses are evaluated by banded

Process robustness and reproducibility of sub-mm wave flip-chip interconnect assembly

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Broadband, nonuniform stripline directional couplers for use in VNA testsets

-parameter measurements between 10 MHz and 500 GHz. For an optimized stripline-to-stripline transition, an insertion loss of less than 1 dB was measured at 500 GHz.

A simplified method for measuring complex S-Parameters dedicated to Synthetic Instrumentation

The design margins for sub-mm-wave flip-chip transitions in three different topologies, coplanar-to-coplanar, stripline-to-coplanar, and stripline-to-stripline, were verified with the realization and S-parameter measurement of passive chip assemblies, which contain the same wiring architecture as our InP DHBT circuit integration. High yield was observed, and less than 2 dB insertion loss per transition was measured above 300 GHz on the stripline-to-stripline design.