Antenna For Wireless Communications Research Articles

Multi-frequency composite wearable antenna for wireless communications

Abstract This paper proposes a multi-band composite wearable antenna for wireless communication, which uses a monopole structure as the radiating body and achieves multi-band characteristics through slit-loading and multi-branching methods. A polymer composite substrate with high dielectric constant and low dielectric loss was prepared using in situ polymerization, and the optimal dielectric constant and loss angle tangent were obtained by controlling the coating ratio of melamine formaldehyde resin (MF) to carbon nanotubes (MWCNTs) and the filler doping rate to achieve miniaturization of the antenna. Comparative experimental results show that the obtained composites have high flexibility and good dielectric properties. The antenna operates in the frequency bands of 2.21-2.52
GHz, 3.07-3.87 GHz, and 4.36-6.03 GHz, which cover the frequency bands of WLAN and WiMAX and 5G applications. The antenna was fabricated and tested, and its performance roughly matched the simulation results. Meanwhile, the antenna has passed the SAR safety test and maintained a stable performance under different curvatures, so it has potential applications in the wireless communication system.

Graphene based series feed linear array antenna for terahertz short range wireless communication

Graphene based series feed linear array antenna for terahertz short range wireless communication

Compact Tri-band Loaded Antenna for wireless Communication and Fifth generation Applications

The tri-band antenna proposed for wireless applications. The proposed antenna with a low profile and compact-T shaped. Two circular rings are connected with stub different pole sizes is shown in this article. The proposed work is carried out using CST Microwave Design Studio on FR-4 substrate with a thickness of 1.6 mm. The suggested antenna works cover all commercial and C band applications in the frequency range of 1 to 6 GHz. It gives triple band at 2.5 GHz for (EBS), 3.5 GHz for 5G band or C-band and 5.8 Ism band for wireless and Wifi Max ,5G applications. An impedance bandwidth of the 15%(2.45 to 2.6),17%(3.32 to 3.6GHz) and 25%(5.5 to 5.8 GHz is obtained. A good conjunction between the simulation and measured results is inferred from design analysis.

Fluorescent antenna based on Förster resonance energy transfer (FRET) for optical wireless communications

The use of fluorescent antennas in optical wireless communications (OWC) has been demonstrated previously, and it has been shown that it is an efficient method for enhancing receiver performance, providing both signal gain and a wide field of view (FoV). To achieve a high concentration gain at the receiver output, the selected fluorophores should have a high photoluminescence quantum yield (PLQY), limited overlap between their absorption and emission spectra, and emit light that can be efficiently detected. In addition, to support a high modulation bandwidth, the photoluminescence (PL) lifetime of the fluorophore needs to be short. In this paper, we propose a new fluorescent antenna architecture based on Förster resonance energy transfer (FRET). Our results show that, due to the photophysical interactions between the energy donor and energy acceptor, the use of FRET simultaneously increases PLQY and reduces PL lifetime. Additionally, employing FRET leads to an increased Stokes shift, ensuring that the emitted light has longer wavelengths, thus reducing self-absorption. This shift can also increase the efficiency with which the fluorescence is detected by a typical silicon (Si) photodetector. Consequently, our OWC results show that a new FRET-based antenna can achieve a significantly higher concentration gain and a wider transmission bandwidth than a conventional non-FRET antenna, leading to much higher data rates.

ICEAA International Conference On Electromagnetics in Advanced Applications IEEE APWC IEEE-APS Topical Conference on Antennas and Propagation in Wireless Communications

ICEAA International Conference On Electromagnetics in Advanced Applications IEEE APWC IEEE-APS Topical Conference on Antennas and Propagation in Wireless Communications

An ultra-compact mechanical antenna based on PTFE highly charged electret for extremely low frequency communications

—Extremely-Low Frequencies (ELF, 30∼300Hz) transmitting antennas in wireless communications are often limited by antenna size and complex impedance matching networks. In this paper, we propose an ultra-small Artificial Electret Type Mechanical Antenna (AETMA), which is composed of a single charge electret and a driving structure, with high radiation efficiency and small size. In order to improve the electric dipole moment of the mechanical antenna, we employ a pin-plate corona polarization technique and a unidirectional stretching treatment to obtain a porous thin-film electret that can stably store a large amount of charge. Its surface charge density can reach 5.355 mC/m2 and we analyze its surface potential stability. To assess the radiation capability of AETMA, the radiation field models of three kinds of mechanical antennas are established and verified by simulation. Additionally, we simulate and compare the planar electret and curved electret configurations to determine the optimal form of AETMA. The radiation intensity of the planar electret is found to be superior under the same moment of inertia. Finally, a 1m-scale artificial electret antenna is designed based on the optimal model. Comparative analysis with existing rotary mechanical antenna schemes confirms the great potential of the proposed AETMA for portable, miniaturized and high-performance wireless communication devices.

Revolutionizing healthcare with metamaterial-enhanced antennas: a comprehensive review and future directions

Abstract The state of the art for wearable antennas for wireless communication and biological applications is compiled in this article. It addresses a wide range of subjects, such as how to use novel materials like Artificial Magnetic Conductors (AMC) and Metamaterial (MTM) structures to enhance antenna performance. It also covers the design of dual-band and reconfigurable antennas and the use of machine learning to optimize aerial design. The main subject of this article is how wearable antennas could lead to advancements in wireless communication and healthcare in the future, perhaps improving lives worldwide. It includes implantable antennas, textile-based antennas, and various flexible graphene-based antenna varieties. The use of wearable antennas for brain stroke diagnostics, wireless body area networks, telemedicine, and breast imaging is covered in this study. Additionally covered are reconfigurable antennas based on Metamaterial (MTM)structures and Wideband on-body antennas inspired by Metamaterials (MTM), both of these applications are useful in the assembly of wearable antennas, which is the main goal of this work. The research also discusses how metamaterials (MTM) might raise the sensitivity of the bioelectric field, enabling precise bioelectric signal monitoring. Metamaterial (MTM) antennas function reliably in a range of biomedical applications and can adjust to the electromagnetic properties.

A Modified Ground for Bandwidth Enhancement of the Microstrip Patch Antenna for 5G Wireless Communications

A Modified Ground for Bandwidth Enhancement of the Microstrip Patch Antenna for 5G Wireless Communications

Design and Analysis of a Quad-Band Antenna for IoT and Wearable RFID Applications

The role of antennas in wireless communication is critical for enabling efficient signal transmission and reception across various frequency bands, including those associated with IoT (Internet of Things), X-band, S-band, and RFID (radio-frequency identification) systems. This paper presents a small quadruple-band antenna with 25 × 40 × 1.5 mm3 dimensions designed for diverse wireless applications. It is adept at operating in the S-band (2.2 GHz), wireless local area network (WLAN) (5.7 GHz), microwave RFID frequency band (5.8 GHz), and X-band (7.7 GHz and 8.3 GHz). While the majority of existing research focuses on antennas covering two or three bands, our work stands out by achieving quad-band operation in the proposed antenna design. This antenna is constructed on a semiflexible Rogers RT5880 substrate, making it well-suited for wearable applications. Computer Simulation Technology (CST) Microwave studio (2019) simulation package software is chosen for design and analysis. The antenna design features a comb-shaped radiating structure, where each “tooth” is responsible for resonating at a distinct frequency with an appropriate bandwidth. The antenna retains stability in both free space and on-body wearability scenarios. It achieves a low specific absorption rate (SAR), meeting wearable criteria with SAR values below 1.6 W/Kg for all resonating frequencies. The proposed antenna demonstrates suitable radiation efficiency, reaching a maximum of 82.6% and a peak gain of 6.3 dBi. It exhibits a bidirectional pattern in the elevation plane and omnidirectional behavior in the azimuth plane. The antenna finds applications across multiple frequencies and shows close agreement between simulated and measured results, validating its effectiveness.

Substrate integrated waveguide-based frequency-tunable self-octaplexing antenna

This communication presents the first-ever substrate integrated waveguide (SIW)-based frequency-tunable self-octaplexing antenna (SOA) for wireless communication. The structure is arranged by implementing eight distinct patches with planar 50-ohm feedlines at the top of the SIW cavity, which realize eight distinct resonant frequencies. Independent tuning of each resonant frequency is achieved by incorporating appropriately allocated pockets in the antenna substrate, which can be filled with solid dielectrics of different permittivity. The obtained tuning range is broad, from 4.76 GHz to 9.82 GHz, with the capability of tuning each port individually. Furthermore, the port isolation (for all ports) that is better than 20.5 dB. The proposed antenna has a realized gain of 3.91, 3.2, 4.05, 4.14, 3.8, 3.37, 3.55 and 3.28 dBi when using Rogers RT-6010 for pocket filling. Furthermore, the antenna provides stable radiation characteristics with precise tuning. The proposed device is suitable for various applications, including multi-standard wireless communications, due to its small size, wide tuning range, consistent radiation patterns, and comparable isolation levels.

Electrical conductivity and morphological observation of hybrid filler: Silver-graphene oxide nanocomposites for wearable antenna

Copper was formerly used for the antenna conductive patch, which was expensive, subject to multipath fading, bulky, ecologically sensitive, and difficult to manufacture. The miraculous nanotechnology of graphene has made it a feasible contender to replace copper due to its extraordinary electrical conductivity and greater strength compared to metal, all while being adaptable and flexible. As a consequence, graphene is utilized in this study to create conductive silver nanocomposites. The electrical conductivity of pressed pellets of the silver-graphene (Ag/GO) sample is measured using the four-point probe method, resulting in an electrical conductivity value of approximately 21.386 S/cm. The proposed wearable antenna is designed, measured, and fabricated, consisting of a circular patch embedded with four slots to enhance the impedance bandwidth, resonating at 2.45 GHz. Besides, the wearable antenna has achieved a high gain of 11.78 dBi and a return loss of more than −20 dB. In consideration of health and safety concerns in wearable devices, the specific absorption rate (SAR) is evaluated. The SAR is determined to be 0.9 W/kg per 10 g of tissue for an input power of 0.5 W, confirming the safety of the proposed graphene wearable antenna for use in wearable devices. These findings suggest promising prospects for the utilization of Ag/GO nanocomposites as a conductive patch for wearable antennas in wireless communication.

Notice of Removal: Design, fabrication and measurements of structurally integrated active antenna for airborne wireless communications

Notice of Removal: Design, fabrication and measurements of structurally integrated active antenna for airborne wireless communications

A 4-port Broadband High-isolated MIMO Antenna for Wireless Communication

A 4-port Broadband High-isolated MIMO Antenna for Wireless Communication

Movable Antennas for Wireless Communication: Opportunities and Challenges

Movable Antennas for Wireless Communication: Opportunities and Challenges

Modelling the elevation power angle spectrum of a MIMO channel

<p>Multiple-Input Multiple-Output (MIMO) channel modelling is constantly researched, and the innovation of its three-dimensional (3D) models is the introduction of the elevation domain parameters, in particular the elevation angle of arrival (EOA) and elevation angle of departure (EOD) where their power angle spectrum (PAS) and their angular spread (AS) greatly impact the 3D MIMO performance. PAS is the basic characteristic used to estimate and model angular dispersion in wireless channels. Propagating signal waves are constrained into a path having an angle within which the power is contained. One of the scenes that will have a significant effect on these parameters is the relative height between the BS and the building. They will also depend on the distance between the base station (BS) and the user equipment (UE). In this work, we investigate the effect of distance and height on the power angle spectrum of a street canyon and a high-rise scenario in the urban environment. The wireless Insite X3D ray tracing engine and a 3D digital map of the environment were used for the simulation. It is seen that the elevation power spectrum (EPS) in the elevation domain decreases with distance and height in both scenarios for the arrival and departure. The appearance of multiple peaks leads to a double-normal distribution in the arrival of the high-rise as height increases, which is a result of reflections from multiple clusters. The azimuth power spectrum (APS) in the azimuth domain also decreases with distance and height at the arrival but increases with distance and height at the departure. The result of the power angle spectrum in this work can be used for modelling angular dispersion as well as designing adaptive antennas for wireless communication.</p>

SIW-based frequency-adjustable antenna for IoT-based duplex wireless devices

This paper proposes a compact and frequency-adjustable/reconfigurable dielectric (DR)-loaded eighth-mode substrate integrated waveguide (EMSIW) antenna for duplex wireless communications. The miniaturization of the resonators is realized using a rectangular slot and high isolation is achieved by keeping a reasonable space between them. The proposed design is simulated using a three-dimensional (3D) full-wave simulator, then analysed with a circuit model and finally validated experimentally. Frequency-reconfigurability in the suggested antenna is achieved by placing DRs with different permittivities in the designated holes that are realized in the open-ended portion of each resonator. Consequently, the lower- and high-resonant bands can be reconfigured from 4.70 to 5.23 GHz and from 5.55 to 6.34 GHz, respectively. It is worth mentioning that both resonant band can be independently reconfigured. Moreover, the inter-resonator coupling is always lower than −23.5 dB in the bands of interest. Furthermore, the peak realized gains are always greater than 4.7 dBi in the lower frequency band and 5.5 dBi in the higher one. The suggested antenna has stable radiation properties in both bands in all frequency ranges. Hence, this design is suitable for compact reconfigurable devices due to its compactness, large frequency ranges, stable radiation patterns, and high isolation.

Millimeter-Wave and Short-Range Wireless Communication Antenna Based on High-Conductivity Graphene-Assembled Film.

Millimeter-wave and short-range wireless communication is an important part of the Internet of Things due to its advantages of high transmission speed and large data capacity. In this paper, two antenna arrays operating at typical millimeter-wave bands (45 and 60 GHz) based on graphene-assembled films (GAF) are proposed for short-range wireless communication application. The 45 GHz graphene-assembled film antenna array is in the form of a magnetoelectric dipole antenna with a strip slot coupling to achieve bidirectional radiation, which offers an operating bandwidth of 40-49.5 GHz with a realized gain of 11.8 dBi. The 60 GHz graphene-assembled film antenna utilizes a microstrip discontinuous radiation array to achieve radiation with an operating bandwidth of 59-64 GHz, reaching the peak realized gain of 14.92 dBi over the working frequency. Finally, we proposed an experimental validation to verify the transmission performance of both antenna arrays in an actual conference room. The results show that the signal drops slowly in the room with drop rates of 0.064 dB/cm (at 45 GHz) and 0.071 dB/cm (at 60 GHz), while it steeply dropped through the wall with the drop rates of 2.3 and 3.13 dB/cm, more than 35-fold difference in signal drop rates in the room and through the wall. It has been confirmed that the proposed antenna arrays can successfully realize fast indoor short-range wireless communication while also preventing signal leakage through walls, thereby enhancing the security of information. In summary, this is the first time that we have applied graphene-based materials to millimeter-wave and short-range wireless communications, revealing the significant potential of carbon-based materials in high-frequency communication systems.

Reconfigurable Antenna for Wireless Communication: Recent Developments, Challenges and Future

Reconfigurable Antenna for Wireless Communication: Recent Developments, Challenges and Future

Broadband large-angle beam scanning with dynamic spin energy distribution based on liquid crystal cascaded bilayer metasurface

Abstract Dynamic manipulation of terahertz (THz) beams plays an important role in THz application systems. The PB metasurface provides an effective scheme for space separation and deflection of the spin beam. However, mirror symmetry locking of the conjugated spin states severely limits the versatility of the device. In this work, we demonstrate a liquid crystal (LC) cascaded bilayer metasurface that includes an LC layer, anisotropic metasurface, and PB metasurface. By controlling anisotropy and polarization conversion effects, dynamic spin asymmetric transmission is realized. Meanwhile, two different dynamic energy distribution processes are realized between the L and R state with the corresponding deflection side. The results show that the device achieves a large angular spatial dispersion within the frequency-angle scanning range of ±35° to ±75° corresponding to the broadband range of 0.6–1.1 THz. Moreover, it achieves a spin beam spatial separation with a maximum proportion of energy distribution greater than 26 dB, and the active modulation rate in the energy distribution process reaches 98 %. This work provides a dynamic THz spin conversion and efficient large-angle beam scanning, with important potentials in wavelength/polarization division multiplexing and frequency-scanning antenna for large-capacity THz wireless communication, radar, and imaging systems.

A Conformal Tri-Band Antenna for Flexible Devices and Body-Centric Wireless Communications.

A conformal tri-band antenna tailored for flexible devices and body-centric wireless communications operating at the key frequency bands is proposed. The antenna is printed on a thin Rogers RT 5880 substrate, merely 0.254 mm thick, with an overall geometrical dimension of 15 × 20 × 0.254 mm3. This inventive design features a truncated corner monopole accompanied by branched stubs fed by a coplanar waveguide. The stubs, varying in length, serve as quarter-wavelength monopoles, facilitating multi-band functionality at 2.45, 3.5, and 5.8 GHz. Given the antenna's intended applications in flexible devices and body-centric networks, the conformability of the proposed design is investigated. Furthermore, an in-depth analysis of the Specific Absorption Rate (SAR) is conducted using a four-layered human tissue model. Notably, the SAR values for the proposed geometry at 2.45, 3.5, and 5.8 GHz stand at 1.48, 1.26, and 1.1 W/kg for 1 g of tissue, and 1.52, 1.41, and 0.62 W/kg for 10 g of tissue, respectively. Remarkably, these values comfortably adhere to both FCC and European Union standards, as they remain substantially beneath the threshold values of 1.6 W/kg and 2 W/kg for 1 g and 10 g tissues, respectively. The radiation characteristics and performance of the antenna in flat and different bending configurations validate the suitability of the antenna for flexible devices and body-centric wireless communications.