Conformity Magazine - September 2007 - (Page 14)

We propose the use of time-domain technology to similarly remove unwanted signals from the measurement. By applying time-gating to insertion loss data, a free-space environment can be mathematically simulated. This concept is not a new one; a major equipment manufacturer offered this possibility several decades earlier [3, 4]. What is new in this paper is the application of this method to determining FSAFs for the EMC community. Further, this method is applied to data over a wide range of frequencies from 30 MHz to 9 GHz. Measurement Process Test Procedure in 3:35 PM Page gital Ed 1-2h 1/18/07Frequency Domain 1 The NIST ultrawideband measurement system has been used for other applications [5, 6] and is outlined in Figure 1. The system consists of a set of frequency specific antennas, a commercially available vector network analyzer, a computer with data collection and processing software, and precision 50 Ω interconnecting cables. In this case, the antennas were the items to be tested. Antennas used for this demonstration were a pair of dual ridged horns (DRG) measured from 1 to 9 GHz, a pair of larger dual ridged horns (large DRG) covering 200 MHz to 2 GHz, and a pair of biconical dipoles for 30 to 300 MHz. The same basic procedure was used for each pair of antennas. First, the antennas were set up over an OATS and the insertion loss data measured in the frequency domain. The measured Figure 1: The NIST ultrawideband measurement system with two test antennas Figure 2: Typical setup of the ultrawideband system for free-space antenna factor measurements over the NIST OATS Another Step Forward View every page of Conformity magazine digitally. That includes every article, every NewsBreak, every ad, everything you’ve come to expect from Conformity, The Integrated Authority on EMC Compliance and Design. � View every page of Conformity as it appears in print. View advertisers’ web sites with one click. Print pages. Save an offline version to your desktop. Send the digital issue to a friend via e-mail. READERS: Sign up to receive your digital edition at www.conformity.com. ADVERTISERS: Activate your advertisement link today. Call 978-486-0888 14 Conformity September 2007 � � � � www.conformity.com http://www.conformity.com http://www.conformity.com

Table of Contents Feed for the Digital Edition of Conformity Magazine - September 2007

Contents Editor’s Note FCC Extends Disability Access Requirements to VOIP Commission Fines Importer $3 Million Over Non-Compliant TVs FCC Gets Tough on Retailers Over Analog TV Tuner Labeling Analog Cellular Service Sunset Date Reaffirmed Commission Adopts Recommendations of Katrina Panel Free-Space Antenna Factors Through the Use of Time-Domain Signal Processing Editorial Correction ESD Open Forum An Update on Revisions to IEC 61000-4-2, the Basic Standard on ESD Practical Advice for Meeting the DFS Testing Requirements of the FCC The EMC Impact of Embedded Software ESD Design Buyer's Guide Tate Renominated to the FCC EPA Releases Report on U.S. Electronic Waste Additional Standards For The EU’s Toy Directive Medical Device Manufacturer Enters Consent Order Updated Guidance Document on Laser Products Issued FDA Offers Advice on Defective Heating Pads CPSC Issues China Product Safety Program Report Other CPSC Actions In The News IEC Standards Update Product Reviews Product News UL Standards Update From Our “You Can’t Make This Stuff Up” Department Looking Back: Items from Past Issues of Conformity Advertisers

Conformity Magazine - September 2007

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