UNIVERSITY OF CINCINNATI DATE: December 16, 2002 I, Bosui Liu , hereby submit this as part of the requirements for the degree of: Doctorate of Philosophy in: Electrical Engineering It is entitled: Vertically Interconnected Wide-Bandwidth Monolithic Planar Antennas for 3D-IC Approved by: Professor Altan M. Ferendeci Professor Chong H. Ahn Professor Kenneth P. Roenker Professor Peter Kosel Professor Donald French Dr. Misoon Mah VERTICALLY INTERCONNECTED WIDE- BANDWIDTH MONOLITHIC PLANAR ANTENNAS FOR 3D-IC A dissertation submitted to the Division of Research and Advanced Studies of University of Cincinnati in partial fulfillment of the requirements for the degree of DOCTORATE OF PHILOSOPHY (Ph.D.) in the Department of Electrical and Computer Engineering and Computer Science of the College of Engineering 2002 by Bosui Liu B.S., Shanghai Jiaotong University, 1996 Committee Chair: Professor Altan M. Ferendeci ABSTRACT For the last two decades, planar monolithic microwave integrated circuit (MMIC) has reached its limitations and can no longer address the needs of the next generation microwave communication systems. The three-dimensional monolithic microwave integrated circuit concept (3D-MMIC) is the key to reduce the volume, weight and cost of the next generation microwave IC while still maintaining high level of performance and functionality. Applying 3D- MMIC technology to a phased array antenna system yields a novel multilayer monolith T/R module in which active devices and the planar antenna together with their associated networks are monolithically processed, vertically stacked and combined on a single chip within a small volume. The goal of this research is devoted to the development and implementation of a novel wide bandwidth planar antenna configuration using new concepts provided by the 3D-MMIC technology. The major challenges lie in the design of efficient antenna structures on very thin substrates with closely spaced bottom ground planes. The two-arm narrow-slotted Archimedean spiral antenna was chosen as the final configuration due to its broadband radiation characteristics and less dependency on substrate thickness. With the slot width being comparable to the substrate thickness, efficient radiations were achieved from the spiral antennas with substrates that were 0.073λg, 0.0056λg, and 0.0038λg thick. Both computational and experimental results have shown that narrow slot design is the key to increased bandwidth and efficiency of the thin substrate slot antenna. And only the Archimedean spiral design can keep the slot at a constant width while taking advantage of the frequency-independent i characteristic of the spiral antenna. Furthermore, in order to feed the two-arm spiral antenna, a wide bandwidth balun circuit compatible with 3D-IC configuration was also developed. As a demonstration of the next generation phased array antenna systems using 3D-MMIC T/R module, a 4-element linear antenna array was assembled using the monolithically processed Archimedean spiral antennas and loaded-line phase shifter. Also, a unique fabrication procedure has been developed to implement the vertically interconnected Archimedean slotted spiral antenna and the feeding balun circuit. ii Bosui Liu 2002 All Rights Reserved iii Dedicated to my wife and father iv ACKNOWLEDGEMENTS Many thanks are due my thesis advisor, Professor Altan M. Ferendeci, for his guidance and mentorship. Dr. Ferendeci has been an exceptional model with his academic insights and his accessibility to students. Appreciation is also extended to my dissertation committee: Professor Chong H. Ahn, Professor Kenneth P. Roenker, Professor Peter Kosel, Professor Donald French from the Department of Mathematics and Dr. Misoon Mah from AFRL. Also, Professor David Mast from the Department of Physics has been a great help for the Near-Field measurement on the spiral antennas. Special mention is given to my wife Lan, for her support throughout these last 5 years, without which attending graduate school would have been much more difficult. Furthermore, weekly conversations with my father have given me extraordinary motivation and inspiration. I would also like to thank Mr. James Cook and Dr. Shih-lin Lu for the discussions on antennas and other topics. Many thanks also go to my colleagues, faculty and staff at the ECECS department of University of Cincinnati, especially Yu Albert Wang, Qinghua Kang, Peng Xu, Oleh Krutko, Mahmood Samiee, Linda Gruber, Ron Flenniken, Hongjin Cho, Ji Chen, Jianjing Tang, Rong Rong and Jin Sun. I apologize in advance for anyone that I may have missed. This work was also supported in part by AFRL. (Contract No: F33615-96-2- 1945) v LIST OF RELATED PUBLICATIONS B. Liu, A. M. Ferendeci, Broadband Slotted Spiral Antennas With Thin Dielectric Substrates, Proc. 2002 IEEE Radio and Wireless Conference (RAWCON2002), Boston, MA, August 11-14, 2002, Session: P1.8. B. Liu, A. M. Ferendeci, 3D Broadband Slotted Spiral Antennas with Thin Dielectric Substrates, Proc. 2002 IEEE AP-S International Symposium and URSI National Radio Science Meeting, San Antonio, TX, June 16-21, 2002, Paper # 940. A. M. Ferendeci, Q. Kang, B. Liu, and M. Mah, Characterization of Monolithically Processed Vertical Interconnects for Microwave 3DIC, Proc. IPACK '01 The Pacific Rim/ASME International Electronic Packaging Technical Conference and Exhibition, Kauai, Hawaii, July 8–13, 2001, Paper # IPACK2001-15777. A. M. Ferendeci, P. Xu, B. Liu, Y. A. Wang, Q. Kang, and M. Mah, 3D-IC Hybrid Power Amplifier for Vertically Interconnected Multilayer Phased Array Antenna Module, Proc. 2001 Government Microcircuit Applications Conference (GOMAC), March 2001. B. Liu, Y. A. Wang, G. Kang, A. M. Ferendeci, and M. Mah, Vertically Interconnected 3D Module for Conformal Phased Array Antennas, Proc. 2000 IEEE International Conference on Phased Array Systems and Technology, Dana Point, California, May 20-26, 2000, pp. 49-52. vi A. M. Ferendeci, B. Liu, Q. Kang and M. Mah, Vertically Interconnected Multilayer Microwave Circuits, Proc. 2000 Government Microcircuit Applications Conference (GOMAC), March 2000. Y. A. Wang, Q. Kang, B. Liu, A. M. Ferendeci, and M. Mah, Interlayer MEMS RF Switch for 3D MMICs, Digest. 2000 IEEE MTT-S International Microwave Symposium, Boston, MA, June 2000, Vol. 2, pp. 1245 -1248. B. Liu, Y. A. Wang, Q. Kang, P. Xu, A. M. Ferendeci and M. Mah, Micromachined 3D Multilayer Monolithic Microwave Circuits, Proc. NASA Ideas Seminar - Technology Presentations, Cleveland, OH, Nov. 1999. A. M. Ferendeci, B. Liu, H. Huang, M. Mah, and L. Liou, 3D Multilayer Monolithic Microwave (M3) Passive Transmitter Module, Digest. 1999 IEEE MTT-S International Microwave Symposium, Anaheim, CA, June 1999, Vol. 2, pp. 445 -448. A. M. Ferendeci, B. Liu, Y. Tang, H. Huang, and M. Mah, Multilayer Monolithic Microwave (M3) Circuits, Proc. 1999 Government Microcircuit Applications Conference (GOMAC), Monterey, CA, March 8-11, 1999. vii TABLE OF CONTENTS ABSTRACT ........................................................................................................I ACKNOWLEDGEMENTS.............................................................................V LIST OF RELATED PUBLICATIONS ......................................................VI TABLE OF CONTENTS ............................................................................VIII LIST OF TABLES ..........................................................................................XI LIST OF FIGURES .....................................................................................XIII CHAPTER 1 INTRODUCTION .....................................................................1 1.1 THREE DIMENSIONAL MONOLITHIC MICROWAVE INTEGRATED CIRCUITS (3D MMICS).....................................................................................................2 1.2 BROADBAND SLOTTED SPIRAL ANTENNA FOR 3D MMIC T/R MODULE ...4 1.3 3D-MMIC PHASED ARRAY ANTENNA SYSTEM.........................................7 CHAPTER 2 WIDE BANDWIDTH MONOLITHIC PLANAR ANTENNA’S DESIGN....................................................................................10 2.1 PLANAR ANTENNA CONFIGURATIONS ......................................................10 2.1.1 Common Planar Antennas................................................................10 2.1.2 Slot Antennas ....................................................................................13 2.1.3 Cavity-backed Slot Antenna .............................................................16 2.2 SPIRAL ANTENNA......................................................................................21 2.2.1 Background.......................................................................................22 2.2.2 Theory of Operation .........................................................................25 2.2.3 Wire Spiral and Slot Spiral...............................................................29 2.3 ANALYSIS METHODS.................................................................................29 2.3.1 Introduction to FDTD Method .........................................................30 2.3.2 FDTD Formulation...........................................................................31 2.3.3 Coding Considerations.....................................................................35 2.3.4 Validation of FDTD code: A Patch Antenna...................................36 2.4 SUMMARY .................................................................................................39 CHAPTER 3 BROADBAND SLOTTED