Real-time 3-d Localization using Radar and Passive Surface Acoustic Wave Transponders Jason ...

261 Pages·2012·14.54 MB·English

Real-time 3-d Localization using
Radar and Passive
Surface Acoustic Wave Transponders
by
Jason Michael LaPenta
Submitted to the Department of Media Arts and Sciences,
School of Architecture and Planning
in partial ful(cid:12)llment of the requirements for the degree of
Masters of Science
at the
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
August 2007
(cid:0) Massachusetts Institute of Technology 2007. All rights reserved.
Author ..............................................................
Department of Media Arts and Sciences,
School of Architecture and Planning
August 11th, 2007
Certi(cid:12)ed by..........................................................
Professor Joseph A. Paradiso
MIT Media Laboratory
Thesis Supervisor
Read by .............................................................
Professor Henry I. Smith
Department of Electrical Engineering & Computer Science
Thesis Reader
Read by .............................................................
Principal Research Scientist V. Michael Bove, Jr.
MIT Media Laboratory
Thesis Reader
Accepted by.........................................................
Professor Deb Roy
Chairperson, Departmental Committee on Graduate Students
Program in Media Arts and Sciences

Real-time 3-d Localization using
Radar and Passive
Surface Acoustic Wave Transponders
by
Jason Michael LaPenta
Submitted to the Department of Media Arts and Sciences,
School of Architecture and Planning
on August 11th, 2007, in partial ful(cid:12)llment of the
requirements for the degree of
Masters of Science
Abstract
This thesis covers ongoing work into the design, fabrication, implementation, and
characterizationofnovelpassive transpondersthatallowrangemeasurements atshort
range and at high update rates. Multiple RADAR measurement stations use phase-
encoded chirps to selectively track individual transponders by triangulation of range
and/or angle measurements. Nanofabrication processes are utilized to fabricate the
passive surface acoustic wave transponders used in this thesis. These transponders
have advantages over existing solutions with their small size (mm(cid:2)mm), zero-power,
high-accuracy, and kilohertz update rates. Commercial applications such as human
machine interfaces, virtual training environments, security, inventory control, com-
puter gaming, and biomedical research exist.
A brief review of existing tracking technologies including a discussion of how their
shortcomings are overcome by this system is included. Surface acoustic wave (SAW)
device design and modeling is covered with particular attention paid to implementa-
tion of passive transponders. A method under development to fabricate SAW devices
with features as small as 300nm is then covered in detail. The electronic design of
the radar chirp transmitter and receiver are covered along with the design and imple-
mentation of the test electronics. Results from experiments conducted to characterize
device performance are given.
Thesis Supervisor: Professor Joseph A. Paradiso
Title: MIT Media Laboratory
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Biography
Jason LaPenta received his B.S. in Electrical engi-
neering from the University of Illinois in Urbana{
Champaign (UIUC) in January of 2001. He spe-
cialized in control systems and worked at a re-
search assistant on vision tracking projects. While
at UIUC, Jason’s summers were spent interning at
Philips Semiconductors (Zu(cid:127)rich, Switzerland), Boe-
ing(Seattle, Washington), andProcterandGamble
(Cincinnati, Ohio). Aftergraduation,Jasonworked
for (cid:12)ve years in the control systems group at MIT Lincoln Laboratories on such
projects as the Mars laser communication experiment.
Jason left Lincoln Laboratory in 2005 to pursue graduate research at the MIT
MediaLaboratoryintheResponsiveEnvironments GroupheadedbyProfessorJoseph
Paradiso.
While thatdemands ofgraduateschool leave little free{time, when available Jason
enjoys Underwater Hockey, caving, kayaking, sailing, and woodworking.
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Acknowledgments
This thesis, and all the wonderful opportunities I have had at MIT were possible
because of my adviser Professor Joe Paradiso, the Responsive Environments Group,
and the Media Laboratory community. Without professor Paradiso’s commitment
to this project, especially obtaining the substantial resources necessary, none of this
work would have been possible. I would like to especially thank Professor Paradiso
for all of the hard work put into this project.
Microfabrication would have been an insurmountable obstacle without the gen-
erous support and dedication of the faculty, scientist, students, and sta(cid:11) of the Ex-
perimental Microfabrication Laboratory (EML), Nanostructure Laboratory (NSL),
and Research Laboratory of Electronics (RLE). From the very (cid:12)rst day I stepped
into a fabrication laboratory, knowing absolutely nothing about applied fabrication,
Kurt Broderick patiently mentored me through every step of fabrication to realize
my (cid:12)rst operational devices. I want to thank all the people at the the Nanostructures
Laboratory, who demonstrated a truly exceptional level of collaboration, helpfulness,
and openness that I’m am very lucky to have been a part of. Laboratory directors
Professor Karl Berggren and Professor Hank Smith provided invaluable insight into
many of the fabrication problems I encountered. Their hard work and dedication pro-
vided the laboratory, tools, and environment of collaboration essential to fabricating
my high-frequency devices. James Daley worked very hard to keep all the tempera-
mental laboratory machinery running smoothly and promptly provided me with all
the supplies and processing I needed. Many long hours were spent by Mark Mondol
checking and writing my designs using the VS-26 SEBL tool and teaching me to use
the Raith{150 SEBL tool. Whenever I had a quick question, Tim Savas would drop
what he was doing to answer and show me the proper methods. In consulting with
Tim I learned a lot about practical fabrication considerations that are only learned
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in application. There are too many students who helped me in NSL to mention here,
though I greatly thank all of them and the NSL community.
DanielSmalley, afriendandfellowMediaArtsandSciencesgraduatestudent, gave
an enormous amount of advice during our many discussions of our similar projects. I
would like to thanks Daniel for the countless hours of conversation through which his
suggestions and insights saved even more hours of work. A special thanks to Roshni
Cooper, the undergraduate research assistant whose hardwork implementing the user
interface and FPGA code allowed me to focus on fabrication while collecting data.
And I especially thank my wife Cindy for all she has done during the most de-
manding time of my life.
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Contents
1 Introduction 23
1.1 Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
1.2 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
1.3 Related Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
2 Surface Acoustic Wave Devices 39
2.1 Properties of Lithium Niobate . . . . . . . . . . . . . . . . . . . . . . 42
2.2 Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
2.3 Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
3 Micro{Fabrication 57
3.1 Mask Design and Layout . . . . . . . . . . . . . . . . . . . . . . . . . 62
3.2 Substrates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
3.3 Substrate Preparation and Cleaning . . . . . . . . . . . . . . . . . . . 71
3.4 Lithography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
3.4.1 Photoresists . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
3.4.2 Coating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
3.4.3 Contact Lithography . . . . . . . . . . . . . . . . . . . . . . . 78
3.4.4 Conformable Vacuum Mask Lithography . . . . . . . . . . . . 79
3.4.5 Scanning Electron Beam Lithography . . . . . . . . . . . . . . 80
9
3.4.6 Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
3.4.7 Resist Developing . . . . . . . . . . . . . . . . . . . . . . . . . 85
3.5 Descum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
3.6 Deposition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
3.7 Lift{o(cid:11) and Etching . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
3.8 Mounting/Packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
4 Electronic Design 99
4.1 System Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
4.2 Analog Components and Test Equipment . . . . . . . . . . . . . . . . 106
4.3 Impedance Matching . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
4.4 SAW Filter Measurements . . . . . . . . . . . . . . . . . . . . . . . . 113
4.5 SAW Transponder Measurements . . . . . . . . . . . . . . . . . . . . 115
4.6 FPGA Hardware Description . . . . . . . . . . . . . . . . . . . . . . . 116
4.7 Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
5 Testing and Characterization 127
5.1 SAW Device 0x2C9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
5.2 SAW Device 0x2E8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
5.3 SAW Device 0x0E3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
6 Conclusion 137
Bibliography 141
A Lithography Masks 151
A.1 Mask 1 Generation Scripts . . . . . . . . . . . . . . . . . . . . . . . . 151
A.2 Mask 2 & 3 Generation Scripts . . . . . . . . . . . . . . . . . . . . . 178
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