Jae-Deok Lim

A Novel Shielding Effectiveness Matrix of Small Shield Cans Based on Equivalent Dipole Moments for Radio-Frequency Interference Analysis

A definition of a shielding effectiveness (SE) matrix for small shield cans used to suppress intra-system noise coupling in mobile devices is proposed. Assuming shield cans enclosing a noise source can be modeled as equivalent dipole moments along with integrated circuits (ICs), a new SE matrix for radio-frequency interference analysis is defined as a ratio of equivalent dipole moments with and without a shield can. The equivalent dipole moments are experimentally extracted using a GTEM cell and two types of probes (monopole and loop), which mimic well the radiations of ICs. Furthermore, the estimation of suppression of noise coupling to an antenna using the proposed SE matrix is successfully validated through numerical simulations.

Software-Based Instrumentation for Localization of Faults Caused by Electrostatic Discharge

Electrostatic discharge (ESD) is often the cause of system-level failure or malfunction of embedded systems. The underlying faults are difficult to localize, as the information gained from the hardware-based diagnostic methods typically in use lacks sufficient detail. The alternative proposed in this paper is software instrumentation that monitors key registers and flags to detect anomalies indicative of failure. In contrast to hardware-based techniques, which use invasive probes that can alter the very phenomena being studied, the proposed approach makes use of standard peripherals such as the serial or Ethernet port to monitor and record the effect of ESD. We illustrate the use of this software instrumentation technique in conjunction with a three-dimensional ESD injection system to produce a sensitivity map that visualizes the susceptibility of various segments of an embedded system to ESD.

Electric and magnetic field shielding evaluation of board level shield can using TEM cell

This paper proposes a simple electric and magnetic field shielding evaluation method of board level shield can using Transverse Electro-Magnetic cell (TEM cell). Small sized electric and magnetic probes (antennas) are installed on the top of a TEM cell with and without shield can below the probe, and 3-port S-parameters are measured, which are used to calculate the electric and magnetic dipole moments of the probes transferred to the other two ports in the TEM cell. The calculated data effectively evaluated the shielding effectiveness of the shield cans with various ventilation holes in both electric field and magnetic field, separately. Finally, the measured shielding effectiveness was validated by numerical simulation and thus reliable results were obtained.