Uwb Antenna

Antenna Design for Ultra Wideband Radio
by Johnna Powell
B.S., Electrical Engineering New Mexico State University, 2001 SUBMITTED TO THE DEPARTMENT OF ELECTRICAL ENGINEERING IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN ELECTRICAL ENGINEERING AT THE MASSACHUSETTS INSTITUTE OF TECHNOLOGY May 7, 2004

© Massachusetts Institute of Technology All RightsReserved Signature of Author . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Department of Electrical Engineering and Computer Science May 7, 2001

Certified by . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Anantha P. Chandrakasan Professor of ElectricalEngineering and Computer Science Thesis Supervisor

Accepted by . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Arthur C. Smith Chairman, Department Committee on Graduate Students

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Antenna Design for Ultra Wideband Radio
by Johnna Powell Submitted to the Department of Electrical Engineering on May 7, 2004 in PartialFulfillment of the Requirements for the Degree of Master of Science in Electrical Engineering

ABSTRACT
The recent allocation of the 3.1-10.6 GHz spectrum by the Federal Communications Commission (FCC) for Ultra Wideband (UWB) radio applications has presented a myriad of exciting opportunities and challenges for design in the communications arena, including antenna design. Ultra Wideband Radiorequires operating bandwidths up to greater than 100% of the center frequency. Successful transmission and reception of an Ultra Wideband pulse that occupies the entire 3.1-10.6 GHz spectrum require an antenna that has linear phase, low dispersion and VSWR ≤ 2 throughout the entire band. Linear phase and low dispersion ensure low values of group delay, which is imperative for transmitting and receivinga pulse with minimal distortion. VSWR ≤ 2 is required for proper impedance matching throughout the band, ensuring at least 90% total power radiation. Compatibility with an integrated circuit also requires an unobtrusive, electrically small design. The focus of this thesis is to develop an antenna for the UWB 3.1-10.6 GHz band that achieves a physically compact, planar profile, sufficientimpedance bandwidth, high radiation pattern and near omnidirectional radiation pattern.

Thesis Supervisor: Anantha P. Chandrakasan Title: Professor of Electrical Engineering

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ACKNOWLEDGEMENTS
First and foremost, I would like to thank my advisor, Anantha Chandrakasan, for the opportunity to work on this project, and also for his support and confidence in my work. His patience and encouragementwere invaluable to me throughout the course of this research. He pushed me to perform to the best of my abilities and gave me opportunities and exposure I never would have had if I had not joined his group. For that, I am extremely grateful. I would also like to thank the entire UWB group including Raul Blazquez, Fred Lee, David Wentzloff, Brian Ginsburg, and former student Puneet Newaskar, fortheir questions, suggestions, help and support. Especially I would like to thank Raul and Fred for their many suggestions and much warranted help. Fred initially proposed the need for a differential antenna, which made my investigation much more interesting. Raul was always helpful, no matter when asked. His kind and caring qualities were much appreciated. In addition, I would also like to thankProfessor David Staelin for connecting me with Lincoln Laboratory in order to perform my very necessary chamber measurements. My results were enhanced greatly with the chamber results. He also provided a great amount of insight and advice. I would also like to thank David Bruno at Lincoln Laboratory, who conducted our radiation experiments in the anechoic chambers. Dr. Catherine Keller and Alan...