| 摘要 |
A new method is introduced to characterize EMC at the IC/ASIC package level. It is designed to excite the modes of radiations found in IC/ASIC packages, and permits the characterization of packages in a way that represents their real application. In the new method, a small antenna designed on a die is mounted inside the package under test. The package is mounted on a carrier PCB that is used to feed a signal into the antenna on the die. Radiated emissions from this set-up are measured. The antenna on the die is measured in free space to obtain a reference level which represents its capability to radiate without shielding. The antenna is then measured inside a package to obtain its capability to radiate with package shielding. The difference between the two measurements will represent the shielding effectiveness or the EMI reduction the package offers to the die. All measurements may conveniently be performed inside a TEM (Transverse Electromagnetic Mode) cell. The antennas designed on the die will permit the measurement of shielding effectiveness, ground bounce and immunity properties of the packages.
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