Wideband and UWB antennas for wireless applications. A comprehensive review

A comprehensive review concerning the geometry, the manufacturing technologies, the materials, and the numerical techniques, adopted for the analysis and design of wideband and ultrawideband (UWB) antennas for wireless applications, is presented. Planar, printed, dielectric, and wearable antennas, achievable on laminate (rigid and flexible), and textile dielectric substrates are taken into account. The performances of small, low-profile, and dielectric resonator antennas are illustrated paying particular attention to the application areas concerning portable devices (mobile phones, tablets, glasses, laptops, wearable computers, etc.) and radio base stations. This information provides a guidance to the selection of the different antenna geometries in terms of bandwidth, gain, field polarization, time-domain response, dimensions, and materials useful for their realization and integration in modern communication systems

Four-element ultrawideband textile cross array for dual-spatial and dual-polarization diversity

The emergence of miniaturized flexible electronics enables on-duty first responders to collect biometrical and environmental data through multiple on-body sensors, integrated into their clothing. However, gathering these life-saving data would be useless if they cannot set up reliable, preferable high-data-rate, wireless communication links between the sensors and a remote base station. Therefore, we have developed a four-element ultrawideband textile cross array that combines dual-spatial and dual-polarization diversity and is easily deployable in a first responder's garment. The impedance bandwidth of the array equals 1.43 GHz, while mutual coupling between its elements remains below -25 dB. For a maximal bit error rate of 1e-4, the array realizes a diversity gain of 24.81 dB. When applying adaptive subcarrier modulation, the mean throughput per orthogonal frequency division multiplexing (OFDM) subcarrier increases by an extra bit/symbol when comparing fourth- to second-order diversity

Wearable, small, and robust: the circular quarter-mode textile antenna

A miniaturized wearable antenna, entirely implemented in textile materials, is proposed that relies on a quarter-mode substrate integrated waveguide topology. The design combines compact dimensions with high body-antenna isolation, making it excellently suited for off-body communication in wearable electronics/smart textile applications. The fabricated antenna achieves stable on-body performance. A measured on-body impedance matching bandwidth of 5.1% is obtained, versus 4.8% in free space. The antenna gain equals 3.8 dBi in the on-body and 4.2 dBi for the free-space scenario. High radiation efficiency, measured to be 81% in free space, is combined with a low calculated specific absorption rate of 0.45 mW/g, averaged over 1 g of tissue, with 500 mW input power

Miniaturized Microwave Devices and Antennas for Wearable, Implantable and Wireless Applications

This thesis presents a number of microwave devices and antennas that maintain high operational efficiency and are compact in size at the same time. One goal of this thesis is to address several miniaturization challenges of antennas and microwave components by using the theoretical principles of metamaterials, Metasurface coupling resonators and stacked radiators, in combination with the elementary antenna and transmission line theory. While innovating novel solutions, standards and specifications of next generation wireless and bio-medical applications were considered to ensure advancement in the respective scientific fields. Compact reconfigurable phase-shifter and a microwave cross-over based on negative-refractive-index transmission-line (NRI-TL) materialist unit cells is presented. A Metasurface based wearable sensor architecture is proposed, containing an electromagnetic band-gap (EBG) structure backed monopole antenna for off-body communication and a fork shaped antenna for efficient radiation towards the human body. A fully parametrized solution for an implantable antenna is proposed using metallic coated stacked substrate layers. Challenges and possible solutions for off-body, on-body, through-body and across-body communication have been investigated with an aid of computationally extensive simulations and experimental verification. Next, miniaturization and implementation of a UWB antenna along with an analytical model to predict the resonance is presented. Lastly, several miniaturized rectifiers designed specifically for efficient wireless power transfer are proposed, experimentally verified, and discussed. The study answered several research questions of applied electromagnetic in the field of bio-medicine and wireless communication.Comment: A thesis submitted for the degree of Ph

Advanced Radio Frequency Antennas for Modern Communication and Medical Systems

The main objective of this book is to present novel radio frequency (RF) antennas for 5G, IOT, and medical applications. The book is divided into four sections that present the main topics of radio frequency antennas. The rapid growth in development of cellular wireless communication systems over the last twenty years has resulted in most of world population owning smartphones, smart watches, I-pads, and other RF communication devices. Efficient compact wideband antennas are crucial in RF communication devices. This book presents information on planar antennas, cavity antennas, Vivaldi antennas, phased arrays, MIMO antennas, beamforming phased array reconfigurable Pabry-Perot cavity antennas, and time modulated linear array

Artificial Magnetic Conductor Integrated Textile Monopole Antenna

Wearable antenna is a fast growing field in application-oriented research, which introduced a new generation of garments capable of monitoring wear health, as well as environmental states. This thesis is concerned with the design and fabrication of a compact textile wearable antenna at operating frequency within the Industrial, Scientific and Medical (ISM) band, intended for integration into a flight jacket of the astronaut inside the habitat. The antenna is integrated with artificial material known as High Impedance Surface (HIS) for performance enhancement. The purpose of the system is to constantly monitor vital signals of the astronauts. The entire design cycle of wearable Co-Planar Waveguide (CPW) fed monopole antenna, starting from simulation-based design to fabricated prototype and antenna testing under different conditions was carried out in this thesis. Because of the lossy nature of human body tissues, the radiation efficiency of the antenna will be reduced due to the absorption of the radiated energy. Hence, changes in the radiation characteristics of the wearable antenna like operating frequency, gain and impedance bandwidth will take place. To overcome these challenges, HIS has been suggested and integrated with the monopole antenna to isolate the antenna from the ambient environments. This wearable antenna was tested under real operating conditions such as bending and crumpling conditions. Moreover, as the antenna operates near human body tissues, Specific Absorption Rate (SAR) assessment is required to consider the safety concerns of the antenna system. SAR analysis based on simulation results has been carried out in this thesis to show a significant reduction in SAR with the usage of HIS in the antenna system

Electromagnetic Band Gap Structure Integrated Wearable Monopole Antenna For Spacesuit

Research and development of body-worn communication systems and electronics have become very prominent in recent years. Some applications include intelligent garments equipped with wireless communication devices for sports, astronauts’ spacesuits [1], and fire fighters’ uniforms [2]. These systems are unthinkable without different kinds of body worn textile or flexible antennas. In this thesis, we will discuss the design and fabrication of a compact wearable textile antenna within the Industrial, Scientific and Medical (ISM) band operating frequency, proposed for incorporation into a flight jacket of the astronaut inside the habitat. The antenna is integrated with artificial material known as Electromagnetic Band Gap (EBG) structures for performance enhancement. The purpose of the system is to constantly monitor vital signals of the astronauts. In this thesis the design, simulation, prototype fabrication and antenna testing under different environmental condition, in a word the entire design cycle of wearable Co-Planar Waveguide (CPW) fed monopole antenna is discussed. As human body tissues are lossy in nature, the radiation efficiency of the antenna will be affected due to the absorption of the radiated energy. Therefore, alteration in the radiation characteristics of the wearable antenna like resonant frequency, realized gain and impedance bandwidth will take place. For overcoming these obstacles, addition of EBG layers are recommended to isolate the antenna from near body environments. The proposed wearable antenna was tested under real operating conditions such as pressure and stretching conditions

A review of recent innovations in remote health monitoring

The development of remote health monitoring systems has focused on enhancing healthcare services’ efficiency and quality, particularly in chronic disease management and elderly care. These systems employ a range of sensors and wearable devices to track patients’ health status and offer real-time feedback to healthcare providers. This facilitates prompt interventions and reduces hospitalization rates. The aim of this study is to explore the latest developments in the realm of remote health monitoring systems. In this paper, we explore a wide range of domains, spanning antenna designs, small implantable antennas, on-body wearable solutions, and adaptable detection and imaging systems. Our research also delves into the methodological approaches used in monitoring systems, including the analysis of channel characteristics, advancements in wireless capsule endoscopy, and insightful investigations into sensing and imaging techniques. These advancements hold the potential to improve the accuracy and efficiency of monitoring, ultimately contributing to enhanced health outcomes for patients.Publisher's VersionQ2WOS:001130630400001PMID:3813832