Bücher von Shiban Kishen Koul

This book presents state-of-the-art trends in reconfigurable active and passive planar antennas and their applications in wireless communication systems operating in the frequency band 5-6 GHz. Due to various key features such as multifunction antenna design, compactness, planar nature, and low cost, these technologies are becoming popular for current and future wireless applications. This book discusses different novel antenna designs and their working principles in detail. The modern and future wireless systems require wideband antennas to accommodate various channels in a single band or in separate bands. The carrier aggregation (CA) has been introduced in the modern wireless systems such as LTE-advanced systems and 5G./6G. In CA, a device can use several channels for transmission and reception. The used channels can exist in the same frequency band (intra-band CA) or in distinct bands (inter-band CA). To accommodate more channels, more bandwidth is required within the operating band. For portable devices, circularly polarized (CP) antennas are more advantageous over linearly polarized antennas since in CP antennas, there is low risk of misalignment and, hence encountering interference. Circularly polarized antenna also provides higher link reliability for the portable devices. To provide high data rates, more bandwidth is needed to accommodate more channels. Various multifunction, compact, and wideband antennas for plethora of applications are addressed in detail in this book. The scope of developing reconfigurable active antennas for application in beam switching, beam steering, wireless charging, security systems, etc., is described. This book concludes by giving glimpses of antenna requirements for future wireless communication systems.

This book offers the readers an opportunity to acquire the concepts of artificial intelligence (AI) enabled sub-THz systems for novel applications in the biomedical field. The readers will also be inspired to contextualize these applications for solving real life problems such as non-invasive glucose monitoring systems, cancer detection and dental imaging. The introductory section of this book focuses on existing technologies for radio frequency and infrared sensing in biomedical applications, and their limited use in sensing applications, as well as the advantages of using THz technology in this context. This is followed by a detailed comparative analysis of THz electronics technology and other conventional electro optic THz setups highlighting the superior efficiency, affordability and portability of electronics-based THz systems. The book also discusses electronic sub-THz measurement systems for different biomedical applications. The chapters elucidate two major applications where sub-THz provides an edge over existing state of the art techniques used for non-invasive measurement of blood glucose levels and intraoperative assessment of tumor margins. There is a detailed articulation of an application of leveraging machine learning for measurement systems for non-invasive glucose concentration measurement. This helps the reader relate to the output in a more user-friendly format and understand the possible use cases in a more lucid manner. The book is intended to help the reader learn how to build tissue phantoms and characterize them at sub-THz frequencies in order to test the measurement systems. Towards the end of the book, a brief introduction to system automation for biomedical imaging is provided as well for quick analysis of the data. The book will empower the reader to understand and appreciate the immense possibilities of using electronic THz systems in the biomedical field, creating gateways for fueling further research in this area.

This book presents state-of-the-art technologies, trends and applications with a focus on the healthcare domain for ultra-wideband (3.1¿10.6 GHz) and 60 GHz (57¿66 GHz) wireless communication systems. Due to various key features such as miniaturized antenna design, low power, high data rate, less effects on the human body, relatively less crowded spectrum, these technologies are becoming popular in various fields of biomedical applications and day-to-day life. The book highlights various aspects of these technologies related to body-centric communication, including antenna design requirements, channel modeling and characterization for WBANs, current fabrication and antenna design strategies for textile, flexible and implanted antennas. Apart from the general requirements and study related to these frequency bands, various application specific topics such as localization and tracking, physical activity recognition and assessment, vital sign monitoring and medical imaging are covered indetail. The book concludes with the glimpses of future aspects of the UWB and 60 GHz technology which includes IoT for healthcare and smart living, novel antenna materials and application of machine learning algorithms for overall performance enhancement.

This book presents the design requirements of antenna integration for modern commercial devices such as smartphones, dongles, and access points. High efficiency antennas for 5G base stations is introduced along with a design example on planar all-metallic antenna.