IEEE P370: A fixture design and data quality metric standard for interconnects up to 50 GHz
(Room Ballroom H)
17 Oct 18
5:00 PM
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5:30 PM
Most high frequency instruments such as Vector Network Analyzers (VNAs) and Time Domain Reflectometers (TDRs) can make very good measurements at the end of a coaxial interface. However, interconnects used in complex systems rarely have coaxial interfaces. The design and implementation of the fixtures used to characterize these devices can have a significant influence on the measured data, and therefore the observed characteristics of the Device Under Test (DUT). The extent of these influences can potentially corrupt the measured data in ways that are not necessarily obvious to the user. Hence some method is needed to ascertain the quality and usability of the measured data. The P370 standard committee was chartered with the task of solving these problems for measurement of interconnects up to 50 GHz. The P370 committee is comprised of approximately 60 members from 25 companies and universities. It has three task groups: Fixture Design, De-embedding Verification, and S parameter Integrity Check. Task Group 1 is drafting guidelines for fixture design to ensure that devices measured with fixtures meeting the design criteria will produce accurate measurement data for the DUT after removing (“de-embedding”) the fixture effects. A design kit of reference structures has been designed and built for use in this process, and extensive measurements have been taken. TG1 has also published a sample software tool for performing the de-embedding process. Task Group 2 has developed an S parameter library for the various structures, is working on the verification process for the de-embedded data when compared to the library data. Error data have been generated and evaluated. Task Group 3 is working on metrics and software tools for checking the integrity of the S parameter data, including passivity, causality, and reciprocity. This paper will review the fixture design guidelines, reference structures, de-embedding techniques, and S parameter quality metrics and validation methods that have been developed as part of the P370 standard. Major test equipment manufacturers and universities have participated in the committee’s work to date. The committee is making good progress, and the draft spec. is currently in review. The target date for the spec. to be ready for ballot vote is early 2019.