® 04/29/2002 CISPR 22, Amendment 1 Ferrite Clamps Ghery S. Pettit, NCE Intel Corporation Corporate Product Regulations

® 04/29/ Topics OATS Qualification Amendment 1, CISPR 22:1997 Problems

® 04/29/ Typical OATS Facility

® 04/29/ OATS Qualification Normalized Site Attenuation –Transmit antenna on turntable center –Receiver antenna on tower –+/- 4 dB and you pass Nothing said about –Power distribution to EUT –Cables to remotely located peripheral devices

® 04/29/ Long Wire End Fed Antennas Random length wire Transmitter at one end Far end – who knows where? xmtr

® 04/29/ Look Familiar? EUT = Transmitter Power cord = Antenna Power feed (from who knows where?) = End support and termination

® 04/29/ Common Unknowns Wire length (resonant frequencies) Wire termination (load) Wire orientation (once it leaves the turntable)

® 04/29/ How To Standardize? Standard wire length and layout –Redesign labs? Major world-wide expense Not likely to be accepted –LISNs at power plugs? What about labs where power is under the table? What about labs where there isn’t room? Solution is to decouple all but the cable in the test area.

® 04/29/ CISPR 22, 3 rd Edition, Amendment 1 (EN 55022:1998, Amendment 1) Adds ferrite clamps –all cables leaving the measurement area for table top EUTs –at the surface of the turntable –1 cable per clamp Published in August Has been adopted by Israel and the EU. Required in EU by 1 August –Israel now, others later

® 04/29/ Ferrite Clamps Table top products only

® 04/29/ Ferrite Clamp Definition The clamp shall –Provide at least 15 dB of loss in a 50 ohm system –30 MHz to 1000 MHz

® 04/29/ Does It Work? Tests performed by Intel and Hewlett Packard in early 2000 to aid in the US vote on the amendment Comb generator to power cord via a CDN Radiated emissions measured every 5 MHz from 30 MHz to 200 MHz 4 lab configurations with a single clamp –Schaffner INA 726 Isolation Clamp 2 lab configurations with 3 different clamps –Schaffner INA 726 Isolation Clamp –MDS 21 Absorbing Clamp –Fischer Custom Communications F-203I-23mm EM Clamp

® 04/29/ Test Setup – No Ferrite Clamp

® 04/29/ Test Setup – With Ferrite Clamp

® 04/29/ Sites – No Ferrite

® 04/29/ Sites – With Ferrite

® 04/29/ Sites - Summary

® 04/29/ Clamps – Two Power Feeds

® 04/29/ Two Power Feeds – No Clamp

® 04/29/ Two Power Feeds – INA 726

® 04/29/ Two Power Feeds – MDS 21

® 04/29/ Two Power Feeds – FCC EM Clamp

® 04/29/ Initial Conclusion Clamps improve repeatability between labs Clamps improve repeatability between different types of power feeds in the same lab Different clamps converge to different solutions –Why?

® 04/29/ One More Clamp Characteristic Need to specify the input impedance for a wire passing through the clamp Measurements show each clamp utilized –Meets the 15 dB loss requirement from 30 MHz to 1000 MHz –Has a different impedance characteristic

® 04/29/ INA 726 Input Impedance

® 04/29/ MDS 21 Input Impedance

® 04/29/ FCC EM Clamp Input Impedance

® 04/29/ Where Do We Go From Here? Problem #1 –CISPR 22 uses ferrite clamps on cables –ANSI C63.4 does not Problem #2 –CISPR 22 does not adequately define the clamps –What should the input impedance to the wire through the clamp be?