DESIGN OF FREQUENCY SYNTHESIZERS FOR SHORT RANGE WIRELESS TRANSCEIVERS A Dissertation by ARI YAKOV VALERO LOPEZ Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY May 2004 Major Subject: Electrical Engineering DESIGN OF FREQUENCY SYNTHESIZERS FOR SHORT RANGE WIRELESS TRANSCEIVERS A Dissertation by ARI YAKOV VALERO LOPEZ Submitted to Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved as to style and content by: ____________________________ ____________________________ Edgar Sánchez-Sinencio José Silva-Martínez (Chair of Committee) (Member) ____________________________ ____________________________ Kai Chang Eva Sevick-Muraca (Member) (Member) ____________________________ Chanan Singh (Head of Department) May 2004 Major Subject: Electrical Engineering iii ABSTRACT Design of Frequency Synthesizers for Short RangeWireless Transceivers. (May 2004) Ari Yakov Valero Lopez, B.S., University of Guanajuato, Mexico; M.S., National Institute for Astrophysics, Optics and Electronics, Mexico Chair of Advisory Committee: Dr. Edgar Sánchez-Sinencio The rapid growth of the market for short-range wireless devices, with standards such as Bluetooth and Wireless LAN (IEEE 802.11) being the most important, has created a need for highly integrated transceivers that target drastic power and area reduction while providing a high level of integration. The radio section of the devices designed to establish communications using these standards is the limiting factor for the power reduction efforts. A key building block in a transceiver is the frequency synthesizer, since it operates at the highest frequency of the system and consumes a very large portion of the total power in the radio. This dissertation presents the basic theory and a design methodology of frequency synthesizers targeted for short-range wireless applications. Three different examples of synthesizers are presented. First a frequency synthesizer integrated in a Bluetooth receiver fabricated in 0.35µm CMOS technology. The receiver uses a low-IF architecture to downconvert the incoming Bluetooth signal to 2MHz. The second synthesizer is integrated within a dual-mode receiver capable of processing signals of the Bluetooth and Wireless LAN (IEEE 802.11b) standards. It is iv implemented in BiCMOS technology and operates the voltage controlled oscillator at twice the required frequency to generate quadrature signals through a divide-by-two circuit. A phase switching prescaler is featured in the synthesizer. A large capacitance is integrated on-chip using a capacitance multiplier circuit that provides a drastic area reduction while adding a negligible phase noise contribution. The third synthesizer is an extension of the second example. The operation range of the VCO is extended to cover a frequency band from 4.8GHz to 5.85GHz. By doing this, the synthesizer is capable of generating LO signals for Bluetooth and IEEE 802.11a, b and g standards. The quadrature output of the 5 – 6 GHz signal is generated through a first order RC – CR network with an automatic calibration loop. The loop uses a high frequency phase detector to measure the deviation from the 90° separation between the I and Q branches and implements an algorithm to minimize the phase errors between the I and Q branches and their differential counterparts. v DEDICATION To my beloved wife Marcia Gisela and daughter Aimee Carolina, my father Mario Alberto, my brother Alberto, and to the memory of my mother Elizabeth. For all their love and unconditional support. vi ACKNOWLEDGMENTS The road of knowledge is long and full of obstacles, but it is exactly going over those obstacles what ultimately enlightens the individual and strengthens his spirit. I have been very fortunate to walk through the road of knowledge, not alone, but accompanied by the brightest and warm hearted individuals I have ever met. I will always treasure the memories of the years we have shared. First of all, I want to express my most sincere thanks to my advisor, Dr. Edgar Sánchez-Sinencio with my deepest gratitude. He has been an inspiration to me since I first met him. His energetic style and never ending flow of ideas has been a model in my academic and personal life. I also want to thank him for trusting in me and encouraging me to pursue this adventure, his moral support during the five years of my program has been fundamental to the conclusion of this lifelong dream. His guidance during the development of my research has been invaluable. I would also like to express special thanks to Dr. Jose Silva-Martínez, who has given me and my family the honor of his friendship. His technical insight and willingness to help have played a very important role in the course of development of this research. In particular at times when there seems to be no solution to a problem, Dr. Silva always came with the simple and “obvious” solution. I want to thank him for giving me the opportunity to experience Texas A&M University during my master’s studies and giving me the last push to come into this group. vii I want to thank Dr. Eva Sevick-Muraca for serving on my committee and allowing me to work in her group. Her enthusiasm and hard working style is so contagious it motivated me to keep going on. I thank Dr. Kai Chang for serving on my committee and giving suggestions to my dissertation. Special thanks go to the secretary of the AMSC, Ms. Ella Gallagher. Her prompt help and joyful character are a valuable treasure for the group. I was very fortunate to work with a group of very enthusiastic and bright students in two major projects, the Bluetooth and Chameleon receivers. Alberto Valdes, Sung Tae Moon, Ahmed Emira, Bo Xia, Ahmed Mohieldin, Chunyu Xin and Wenjun Sheng. Their enormous effort and enthusiasm were key to the successful completion of the projects. The personal and technical experience I obtained through the collaboration with all of them is a very valuable part of my educational experience. I want to thank all my friends for the support and encouragement during all the years I spent in Texas A&M. I want to thank my friend and officemate Alberto Valdes for all his support, advice and for lifting up my spirit when I needed it the most, and Artur Lewinski for being always there. I had the opportunity to work with Sung Tae Moon in three different projects, his optimism and easy going nature were always very important to keep my nerves in control. I also want to thank my friends Antonio, Adriana, Artur, Isabel, David, Benoit, Fikret, Feyza, Fan, Joseph, Erkan, Luis Ignacio, Sony, Gerardo, Joel, Vero, Adan, Regina, Alfonso, Yadhira, Jose Carlos, Lupita, Jose viii Miguel, Tere, Felipe, Chinmaya and Arun for their friendship. Thanks to Keliu, Faramarz for their help in technical discussions. I would like to express my gratitude to Mayo for her invaluable help during these years. The deepest gratitude goes to my beloved wife Marcia Gisela who has always been my inspiration. Her unconditional support, sacrifice and encouragement have been the driving force that keeps me going. I do not have words to thank her for sacrificing her own doctorate to give me the opportunity to go ahead with mine. I am a very fortunate man to have such an intelligent and wonderful woman by my side. I would like, also, to thank my daughter, Aimee Carolina, for making me so happy with all the love she emanates. Her innocence and joyful character provided me with the much needed energy and peace to keep going. Both of the women in my life are the most valuable treasure I have. I want to thank my father, Mario Alberto, and my brother, Alberto, for providing me with love and support through these years. To my late mother, Elizabeth, I want to thank for teaching me that there are no boundaries to our dreams when we are willing to take the risk and put the required effort. She always wanted me to obtain an advanced degree, and now I have the opportunity to show her that her dream has been fulfilled. ix TABLE OF CONTENTS Page ABSTRACT ..................................................................................................................... iii DEDICATION ...................................................................................................................v ACKNOWLEDGMENTS.................................................................................................vi TABLE OF CONTENTS ..................................................................................................ix LIST OF FIGURES......................................................................................................... xii LIST OF TABLES ....................................................................................................... xviii CHAPTER I INTRODUCTION .................................................................................................1 1.1. Background and Motivation............................................................................3 1.2. Short-Range Wireless Communications .........................................................5 1.2.1. Bluetooth ..........................................................................................7 1.2.2. Wireless LAN IEEE 802.11 ...........................................................10 1.2.3. Ultra-Wideband (UWB).................................................................12 1.3. Role of a Frequency Synthesizer in RF Transceivers ...................................17