Slot Antennas - A Comprehensive Survey

Wireless Communication has found a rapid growth over the past decades starting from handheld devices to spacecraft applications. The efficient operation of all such wireless devices depends on the design and proper working of the transmitting and receiving antennas. Microstrip antennas are most commonly preferred for major wireless applications, because of their miniaturized structure, ease of fabrication, low power consumption, flexibility with printed circuit board, low profile, light weight, effective return loss and better radiation properties. This paper provides a comprehensive survey on microstrip antennas whose performance is improved to meet the increasing demand, by introducing slots of different shapes and sizes. These slots of various kinds helps in obtaining wider bandwidth over the C and Ultrawideban

An UltraWideband Full Flexible 4 Elements DGS Based MIMO Antenna for Sub-6 GHz Wearable Applications

Abstract In this article, a compact wearable quad element MIMO antenna is presented operating at 4.5 GHz for 5G n77, n78, and n79 bands with the use of polyester substrate with a size of 80 × 82 × 0.4 mm3. Here T-shaped defected ground structure (DGS) technique has been utilized to improve the impedance bandwidth along with the reduction of the mutual coupling between the radiating elements. The antenna is evaluated in terms of reflection coefficient, gain, efficiency, and radiation pattern. The proposed MIMO antenna attained a maximum simulated gain of 4.3 dBi, and an efficiency of 96 % in the resonating band.Abstract In this article, a compact wearable quad element MIMO antenna is presented operating at 4.5 GHz for 5G n77, n78, and n79 bands with the use of polyester substrate with a size of 80 × 82 × 0.4 mm3. Here T-shaped defected ground structure (DGS) technique has been utilized to improve the impedance bandwidth along with the reduction of the mutual coupling between the radiating elements. The antenna is evaluated in terms of reflection coefficient, gain, efficiency, and radiation pattern. The proposed MIMO antenna attained a maximum simulated gain of 4.3 dBi, and an efficiency of 96 % in the resonating band

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

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

A pocket-integrated miniature, dual-band, and high gain textile MIMO antenna for 5G and WiFi wearable applications

This paper reports a miniature low-profile denim textile 2-port MIMO (multiple-input-multiple-output) antenna for dual-bands: 5G sub-6 3.5 GHz and Wi-Fi 5.2 GHz wearable applications. This MIMO antenna has impedance bandwidths and peak gain of 310 MHz and 8.3 dBi and 950 MHz 13.0 dBi at 3.5 and 5.2 GHz, respectively. This MIMO antenna has a compact area of 0.078 λ02, with both antenna elements of the MIMO being a modified elliptical patch, L-shaped stubs for impedance matching, and a circular decoupling ring to achieve > 25 dB port isolation. The designed antenna is very tiny and integrated into the shirt's pocket. It is tested in two positions, i.e., hidden (integrated inside the pocket, for example, military applications) and visible (when integrated on the pocket surface for conventional communication). Moreover, the antenna's working is analyzed in these positions (hidden and visible), and it was found that it functions well in both 5G sub-6 GHz and Wi-Fi frequency bands with nearly close gain values and communication range. This MIMO antenna has a very small ECC (envelope correlation coefficient) of 0.006/0.002 in both frequency bands, which shows high channel isolation. The 1 gm/10 gm SAR (specific absorption rate) values at 3.5 and 5.2 GHz are 0.034/0.057 and 0.026/0.0132 W/Kg, respectively, substantially lesser than the recommended values of FCC/ICNIRP

Recent Advances in Antenna Design for 5G Heterogeneous Networks

The aim of this book is to highlight up to date exploited technologies and approaches in terms of antenna designs and requirements. In this regard, this book targets a broad range of subjects, including the microstrip antenna and the dipole and printed monopole antenna. The varieties of antenna designs, along with several different approaches to improve their overall performance, have given this book a great value, in which makes this book is deemed as a good reference for practicing engineers and under/postgraduate students working in this field. The key technology trends in antenna design as part of the mobile communication evolution have mainly focused on multiband, wideband, and MIMO antennas, and all have been clearly presented, studied and implemented within this book. The forthcoming 5G systems consider a truly mobile multimedia platform that constitutes a converged networking arena that not only includes legacy heterogeneous mobile networks but advanced radio interfaces and the possibility to operate at mm wave frequencies to capitalize on the large swathes of available bandwidth. This provides the impetus for a new breed of antenna design that, in principle, should be multimode in nature, energy efficient, and, above all, able to operate at the mm wave band, placing new design drivers on the antenna design. Thus, this book proposes to investigate advanced 5G antennas for heterogeneous applications that can operate in the range of 5G spectrums and to meet the essential requirements of 5G systems such as low latency, large bandwidth, and high gains and efficiencies