| Objectives | Background | Approach |
Build an advanced EMI/EMC testing and measurements facility
with the capability of measuring shielding-effectiveness and
transfer-impedance changes with time to provide shielding
degradation and shielding reliability assessment. Contribute
to the establishment of appropriate methods and testing procedures.
Electromagnetic compatibility (EMC) is the ability of electronic equipment to function without either causing electromagnetic interference (EMI) or being disrupted by disturbances. Today, high clock speeds and edge rates as well as relatively low-threshold voltages used in modern digital signal processing have brought EMC to the forefront of products and systems.
Driven by a balance of performance and cost, most of the enclosures in today's commercial computer industry are made of zinc-coated steel with gaskets generally composed of beryllium-copper, tin-coated phosphor bronze or steel. One of the industry-identified concerns with these enclosures is that their shielding performance has been found to decrease with time.
CALCE has been working on EMI shielding degradation problems utilizing its expertise in both reliability and EMC since 1998. CALCE has extended its reliability research into EMI/EMC area and started unique work in the EMI/EMC community that is of significant importance to the electronic industry. While shielding degradation has become an industry concern, the mechanisms and behavior are hard to experimentally assess, and no industrial standards exist to define testing procedures and testing facilities.
CALCE has determined the need to purchase an HP E4433B digital RF signal generator and an EMCO 5407 GTEM EMC test cell. CALCE will manufacture sample fixtures with contact-force control and programming capability, test the sample fixtures, determine the methodology to offset the effect of the fixtures on measurement results, and establish a calibration procedure for accurate and reliable measurement. CALCE will then conduct a case study on the shielding degradation behavior of selected EMI shielding components using the developed system. The results will be used to the reliability assessment of the components.