A Study On The Effects Of Ground Via Fences, Embedded Patterned Layer, And Metal Surface Roughness On Conductor Backed Coplanar Waveguide

Persistent Link:
http://hdl.handle.net/10150/593602
Title:
A Study On The Effects Of Ground Via Fences, Embedded Patterned Layer, And Metal Surface Roughness On Conductor Backed Coplanar Waveguide
Author:
Sain, Arghya
Issue Date:
2015
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Electrical engineers have responded to the increasing demand for circuit speed and functionality by reducing transistor feature size and increasing on-chip transistor density. Consequently, interconnect density, both on-chip and the system level is also increasing. Increasing circuit speed translates into shorter clock cycles and signals with faster edge rates, which have multi-GHz bandwidth. Densely packed parallel interconnects will cause signal integrity problems not only due to the increase in crosstalk noise but also due to the intrinsic low pass filter characteristics of the interconnects. The lossy nature of the interconnects is also going to increase due to metal surface roughness at higher frequencies, which will further degrade the signal quality at the receiver input. Embedded Patterned Layer (EPL), which is a patterned floating metal layer between a signal trace and its return path shows promise in reducing far-end crosstalk (FEXT). EPL also allows designers to modify the characteristic impedance of interconnects by varying the different physical parameters of the EPL. This dissertation analyzes the effect of EPL on conductor backed coplanar waveguides (CB-CPW). CB-CPWs excite higher order modes at high frequencies, so work was done to understand the effect of different ground via fence parameters in suppressing the higher modes which helps increase the interconnect bandwidth. A CB-CPW with ground via fence is called a grounded coplanar waveguide (GCPW). A very basic lumped element model transmission line model was developed to account for the effect of floating metals near a transmission line. This model was then used to explain the effect of EPL on a GCPW with large bandwidth. EPL reduces the characteristic impedance of the transmission line. Engineers can then design narrow high impedance transmission lines and use EPL to reduce the impedance to a desired value. This also allows reduction in crosstalk by increasing the spacing between the transmission lines. The EPL also reduced the differential impedance of a grounded conductor backed edge coupled coplanar waveguide, when it was used for differential signaling. Care must be taken to make sure that the EPL is symmetric to both the legs of the differential pair to avoid differential to common mode energy conversion, which can cause electromagnetic interference (EMI) problems. EPL reduced FEXT while increasing near-end crosstalk (NEXT), when the coupled transmission line system was used for single ended signaling. Finally, a statistical method for modeling transmission line metal surface roughness in three dimensional (3D) full wave electromagnetic solvers was developed to account for increased attenuation in transmission lines, at high frequencies, due to metal surface roughness.
Type:
text; Electronic Dissertation
Keywords:
Embedded patterned layer; Surface roughness; Via fence; Electrical & Computer Engineering; Coplanar waveguide
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Electrical & Computer Engineering
Degree Grantor:
University of Arizona
Advisor:
Melde, Kathleen L.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen
dc.titleA Study On The Effects Of Ground Via Fences, Embedded Patterned Layer, And Metal Surface Roughness On Conductor Backed Coplanar Waveguideen_US
dc.creatorSain, Arghyaen
dc.contributor.authorSain, Arghyaen
dc.date.issued2015en
dc.publisherThe University of Arizona.en
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en
dc.description.abstractElectrical engineers have responded to the increasing demand for circuit speed and functionality by reducing transistor feature size and increasing on-chip transistor density. Consequently, interconnect density, both on-chip and the system level is also increasing. Increasing circuit speed translates into shorter clock cycles and signals with faster edge rates, which have multi-GHz bandwidth. Densely packed parallel interconnects will cause signal integrity problems not only due to the increase in crosstalk noise but also due to the intrinsic low pass filter characteristics of the interconnects. The lossy nature of the interconnects is also going to increase due to metal surface roughness at higher frequencies, which will further degrade the signal quality at the receiver input. Embedded Patterned Layer (EPL), which is a patterned floating metal layer between a signal trace and its return path shows promise in reducing far-end crosstalk (FEXT). EPL also allows designers to modify the characteristic impedance of interconnects by varying the different physical parameters of the EPL. This dissertation analyzes the effect of EPL on conductor backed coplanar waveguides (CB-CPW). CB-CPWs excite higher order modes at high frequencies, so work was done to understand the effect of different ground via fence parameters in suppressing the higher modes which helps increase the interconnect bandwidth. A CB-CPW with ground via fence is called a grounded coplanar waveguide (GCPW). A very basic lumped element model transmission line model was developed to account for the effect of floating metals near a transmission line. This model was then used to explain the effect of EPL on a GCPW with large bandwidth. EPL reduces the characteristic impedance of the transmission line. Engineers can then design narrow high impedance transmission lines and use EPL to reduce the impedance to a desired value. This also allows reduction in crosstalk by increasing the spacing between the transmission lines. The EPL also reduced the differential impedance of a grounded conductor backed edge coupled coplanar waveguide, when it was used for differential signaling. Care must be taken to make sure that the EPL is symmetric to both the legs of the differential pair to avoid differential to common mode energy conversion, which can cause electromagnetic interference (EMI) problems. EPL reduced FEXT while increasing near-end crosstalk (NEXT), when the coupled transmission line system was used for single ended signaling. Finally, a statistical method for modeling transmission line metal surface roughness in three dimensional (3D) full wave electromagnetic solvers was developed to account for increased attenuation in transmission lines, at high frequencies, due to metal surface roughness.en
dc.typetexten
dc.typeElectronic Dissertationen
dc.subjectEmbedded patterned layeren
dc.subjectSurface roughnessen
dc.subjectVia fenceen
dc.subjectElectrical & Computer Engineeringen
dc.subjectCoplanar waveguideen
thesis.degree.namePh.D.en
thesis.degree.leveldoctoralen
thesis.degree.disciplineGraduate Collegeen
thesis.degree.disciplineElectrical & Computer Engineeringen
thesis.degree.grantorUniversity of Arizonaen
dc.contributor.advisorMelde, Kathleen L.en
dc.contributor.committeememberMelde, Kathleen L.en
dc.contributor.committeememberRoveda, Janet M.en
dc.contributor.committeememberXin, Haoen
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