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Shield for Radiative Noise on Discrete Electronic Components

IP.com Disclosure Number: IPCOM000115359D
Original Publication Date: 1995-Apr-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 64K

Publishing Venue

IBM

Related People

Benedict, M: AUTHOR [+4]

Abstract

Disclosed is a shield against radiated noise for discrete electronic components. Grounded wires are looped over the discrete component signal lines to protect against electronic crosstalk and noise.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Shield for Radiative Noise on Discrete Electronic Components

      Disclosed is a shield against radiated noise for discrete
electronic components.  Grounded wires are looped over the discrete
component signal lines to protect against electronic crosstalk and
noise.

      Radiated electronic noise has been an ongoing problem in the
design of printed circuit (PC) boards using discrete components.
Electrical wiring connected to such components cannot be embedded
within the circuit board, and is more susceptable to radiated noise
because it is located on the surface of the board.  In particular,
fiber optic transceivers are susceptible to this problem more than
most components, because they require discrete components (optical
transmitters and receivers) located in close proximity to each other,
often running asynchronously at high frequency.  In the past, the
transmit and receive sides of an optoelectronic module were isolated
in 2 separate housings.  Recent cost reduced transceiver designs use
a unibody design which locates these components close together in a
common package.  This has made the transceiver much more sensitive to
radiated noise (crosstalk) coupling from the transmitter into the
receiver.  Since the receiver is a discrete component, design
constraints prevent it from being directly mounted on the PC board
substrate; various approaches to shielding the signal lines from this
noise must be explored.  Adding a Faraday shield around the entire
receiver and postamp is an expensive solution, which cannot easily be
reworked into existing packages.  Our proposed solution involves the
following steps:
  o  create surface ground pads on both s...