Columns

This article reviews the decibel units used in EMC laboratory measurements and testing. We begin by defining a decibel (dB) unit and proceed to the EMC specific units for voltage, current, power, and impedance measurements.

When designing EMI filters how and where the filter is installed is critical to obtain the desired insertion losses. Usually, the effect of a wrong location or installation is not considered in the design of the filter and surprises appear.

When garments are specified as part of an ESD control program, they must be qualified and verified by testing.

This month we look at what “supplementary symbols” are – and how and when to use them on the safety labels on your products.

We are proud to carry on the tradition of sharing Banana Skins for the purpose of promoting education for EMI/EMC engineers.

Network analyzer measurements require the calibration procedure which utilizes a calibration kit, consisting of a short, open, and a 50 Ω load attachment.

This month’s Hot Topics in ESD column is Part II of a two-part column. Part I appears in the May 2019 issue.

The Banana Skin columns were compiled by Keith Armstrong, of Cherry Clough Consultants Ltd, from items he found in various publications, and anecdotes and links sent in by the many fans of the column.

This Part II of the tutorial illustrates the Bode plots’ use in several EMC applications. EMC applications will include the non-ideal models of resistors, inductors, and capacitors, as well as the spectral bounds on digital clock signals.

EMC radiated problems in HF/VHF ranges are typical in products with switching-mode power supplies (SMPS) as for example flyback and buck converters. Usually no high power is needed to radiate signals well over the legal EMC limits.