Contents


Preface

Ultra Wide Band (UWB) technology has attracted increasing interest and there is a growing demand for UWB for several applications and scenarios. The unlicensed use of the UWB spectrum has been regulated by the Federal Communications Commission (FCC) since the early 2000s. The main concern in designing UWB circuits is to consider the assigned bandwidth and the low power permitted for transmission. This makes UWB circuit design a challenging mission in today's community. The major aim of the book is to introduce the readers to the basic design principles and building blocks that are necessary for such technology. In addition, the latest research innovations, especially in the area of circuits and systems, are presented. Various circuit designs and system implementations are described within this book to give the reader a glimpse of the state-of-the-art examples in this field. The book starts at the circuit level design of major UWB elements such as filters, antennas, and amplifiers; and ends with the complete system implementation using such modules.

The first chapter of the book is titled "Frequency Reconfigurable UWB Antenna Design for Wireless Applications" written by R. K. Sarraswat and M. Kumar. The chapter introduces a reconfigurable antenna suitable for WLAN, WiMAX, WiFi, and UWB wireless applications. The antenna is capable of switching between the narrow band, dual band, and UWB modes by using five p-i-n diodes placed inside an inverted L-shaped ground slot. The proposed design provides for easy integration with cognitive radio and multi radio wireless terminal devices. Radiation characteristics of the proposed antenna are achieved with good impedance matching at these resonant frequencies. The radiation pattern, gain, and efficiency are consistent over all the operating bands, making the proposed antenna a good choice

The second chapter is titled "UWB Circuits and Sub-Systems for Aerospace, Defence, and Security Applications" and is written by E. Limiti and P. E. Longhi. This chapter reviews the topology, technology, and trends of microwave circuits in UWB systems for aerospace and defence applications. This includes front-end and back-end circuits, amplifiers and mixers, ADCs, and chip integration techniques. An outline on multi-functional circuits (Single-Chip Front-Ends and Core-Chips)

The third chapter is titled "Inner Tapered Tree Shaped Ultra Wide Band Fractal Antenna with Polarization Diversity" and is authored by S. Singhal. The chapter introduces a compact third iteration fractal antenna for UWB using an orthogonal arrangement of two antenna elements. The designed antenna has wider bandwidth and excellent polarization diversity performance, which makes it suitable for UWB polarization applications in future wireless communication systems to mitigate the

The fourth chapter is titled "Antennas for UWB Applications" and is authored by S. Nikolaou and A. Quddious. The chapter presents selected antenna designs in relation to the UWB applications and their dictating radiation and operation principles. The demonstrated UWB antennas include antennas for handheld devices used for

for wireless applications.

is also presented.

multipath fading.
