Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.485537
Title: High speed planar electrical data transmission structure modelling using VHDL-AMS with skew and EMI management
Author: Burford, Mark R.
Awarding Body: University of Southampton
Current Institution: University of Southampton
Date of Award: 2008
Availability of Full Text:
Full text unavailable from EThOS. Please contact the current institution’s library for further details.
Abstract:
Signal integrity constraints in modern high speed data communication protocols are becoming increasingly stringent. Consumers are demanding faster, more powerful systems with lower power requirements that require faster internal data transfers over longer distances. These two statements are not mutually' compatible because as frequency increases there are increased losses and increased abberations to the data signal from a variety of sources. It, therefore, becomes increasingly difficult to guarantee a receiver will be able to recover the signal. Large system level time domain simulations have been possible for a while, however, the inclusion of an efficient, compatible and accurate time domain transmission line model that responds to the signal in real time has not as yet been possible. Additionally, as the frequency increases, any difference in transmission time between each component of a differential signal will also increase linearly as the period decreases. This signal skew has not as yet presented a problem to signal integrity or loss. However, as the frequency increases there will be increased signal skew which increases mode conversion so less of the signal will be available for recovery using existing skew compensation methodologies. Mode conversion is the process where the energy in a signal is converted from one mode to anotl}er, with a variety of possible causes. The primary cause of mode conversion in this research is signal skew, which causes a potential gradient between the traces forming a differential pair. This allows energy to be coupled and transferred between the copper traces, causing signal asymmetries. This thesis examines high speed planar copper data transmission structures through the use of time and frequency domain modelling. Models for physical loss, reflection and signal skew are created in the time domain using the hardware description language VHDL-AMS while physical loss, reflection, mode conversion and losses to electromagnetic radiation are modelled in the frequency domain using Agilent's Genesys®. There are three main contributions presented in this thesis. The first of which is a signal dependent time domain methodology of calculating skin depths and dielectric conductances in high speed planar data transmission structures The second contribution is a platform independent time domain model of the main loss mechanisms, including signal dependent skin effect and dielectric conductances for implementation in almost any system level mixed signal simulation up to 7 GHz. The third major contribution is a new methodology of approaching and compensating for losses due to mode conversion and EM loss as caused by signal skew in differential microstrip line pairs up to 15 GHz. These methodologies are to be named as skew and EMI management collectively. Finally, there is a set of guidelines for skew management for layout engineers to take into consideration and combine with their existing in depth knowledge of the theory and practice of signal routing at high speed. This will enable high speed planar data transmission structures to transmit signals over longer distances and at higher frequencies whilst preserving signal integrity, thus permitting the continued use of copper for the next generations of products.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.485537  DOI: Not available
Share: