Browse Prior Art Database

Shielding Effectiveness Set Up

IP.com Disclosure Number: IPCOM000117739D
Original Publication Date: 1996-May-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Dieterich, K: AUTHOR

Abstract

Use of high frequency signals requires well-shielded electronic components to protect them against electromagnetic interference and to guarantee error free operation. To achieve this, electronic components are to be located in metal or metalized enclosures.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 62% of the total text.

Shielding Effectiveness Set Up

      Use of high frequency signals requires well-shielded electronic
components to protect them against electromagnetic interference and
to guarantee error free operation.  To achieve this, electronic
components are to be located in metal or metalized enclosures.

      Enhanced electronic units consists of several such enclosures,
which contain sensitive electronic components.  The interconnection
cables among those enclosures are mostly also shielded for this
reason.

      The shielding effectiveness of such an HF-enclosure is
important and must therefore be well designed.  The kind of
enclosures usually needs cooling openings as well as access covers
which may decrease shielding effectiveness.

      The measuring set, described below, makes it possible, to
evaluate shielding effectiveness of a metal enclosure in an easy and
quickly way.  The Figure shows the block diagram of the test set up.
A network analyzer, for example, (HP-8753A) attached to a highly
qualified 50 Ohm coaxial system, feeds a high frequency spectrum into
the test object (enclosure).  The frequency spectrum is adjustable
and covers the range 30 MHz - 1GHz, depending on the analyzer.  As a
test object usually a metal or matalized enclosure is used.

      The cable shield of the coax cable ends at the enclosure
entrance.  The center conductor runs straight through the enclosure
and is terminated to 50 Ohm at the end.  The unshielded center
co...