Browse Prior Art Database

Radio Frequency Profile Scanner

IP.com Disclosure Number: IPCOM000111417D
Original Publication Date: 1994-Feb-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 67K

Publishing Venue

IBM

Related People

Bryceland, A: AUTHOR [+4]

Abstract

Disclosed is a development/production testing method for Printed Circuit Cards and Board (PCB) that generates an image of RF or magnetic energy patterns plotted over a physical outline of the PCB (Fig. 2). Radiated system EMC problems can be displayed at the component level at any frequency, avoiding costly testing at the assembled level. Benefits are fast feedback, EMC problems found and fixed earlier in development, and as a bench tool, it scores EMC Chamber and Free Field bench correlation time costs.

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Radio Frequency Profile Scanner

      Disclosed is a development/production testing method for
Printed Circuit Cards and Board (PCB) that generates an image of RF
or magnetic energy patterns plotted over a physical outline of the
PCB (Fig. 2).   Radiated system EMC problems can be displayed at the
component level at any frequency, avoiding costly testing at the
assembled level.   Benefits are fast feedback, EMC problems found and
fixed earlier in development, and as a bench tool, it scores EMC
Chamber and Free Field bench correlation time costs.

      It has not been possible to design for good EMC properties from
first principles; neither has a profile scanner been available for
the measurement of EMC fields from PCBs.  Consequently, PCBs are
built, product tested, fixed and tested again repeatedly.

      The purpose of this invention is to produce a diagram of
electric or magnetic energy fields.  These diagrams will show the
highest concentrations of energy at a particular problem frequency.
Design changes can then be applied to the card, and a second scan can
be taken to see the effect on the problem frequency level.

      The set-up (Fig. 1) consists of a flat bed fixture 1 on which a
PCB 2 can be placed.  A bidirectional moving gantry 3 is used to hold
either an electric or magnetic field probe 4 which moves over the
surface of the card 2 at a predetermined height, driven by x and y
coordinate series 5 and 6.

      At each coordinate poin...