文档介绍：Advanced PCB design and layout for EMC Part 6 - Transmission
lines - 1st Part
By Eur Ing Keith Armstrong MIEE MIEEE, Cherry Clough Consultants
This is the sixth in a series of eight articles on good-practice design techniques for
patibility (EMC) for printed circuit board (PCB) design and layout. This
series is intended for the designers of any electronic circuits that are to be constructed on PCBs,
and of course for the PCB designers themselves. All applications areas are covered, from
household appliances; commercial, medical and industrial equipment; through automotive, rail
and marine to aerospace and military.
These PCB techniques are helpful when it is desired to…
Save cost by reducing (or eliminating) enclosure-level shielding
Reduce time-to-market pliance costs by reducing the number of design iterations
Improve the range of co-located wireless ms (GSM, DECT, Bluetooth, IEEE
, etc.)
Use very high-speed devices, or high power digital signal processing (DSP)
Use the latest IC technologies (130nm or 90nm chip processes, ‘chip scale’ packages,
etc.)
The topics to be covered in this series are:
1. Saving time and cost overall
2. egregation and interface suppression
3. PCB-chassis bonding
4. Reference planes for 0V and power
5. Decoupling, including buried capacitance technology
6. Transmission lines
7. Routing and layer stacking, including microvia technology
8. A number of miscellaneous final issues
A previous series by the same author in the EMC & Compliance Journal in 1999 “Design
Techniques for EMC”[1] included a section on PCB design and layout (“Part 5 – PCB Design
and Layout”, October 1999, pages 5 – 17), but only set out to cover the most basic PCB
techniques for EMC – the ones that all PCBs should follow no matter how simple their circuits.
That series is posted on the web and the web versions have been substantially improved over the
intervening years [2]. Other articles and publications by