Wireless Applications Research Articles

Design and Performance Analysis of Multiband Patch Antenna with Metamaterial for Wireless Applications

Design and Performance Analysis of Multiband Patch Antenna with Metamaterial for Wireless Applications

A CPW THz-MIMO antenna with reduced mutual coupling using Frequency Selective Surface for future wireless applications

In this article, we propose a novel THz-MIMO antenna system for future wireless applications. The performance of THz systems is prominently influenced by the MIMO configuration of the antenna. Increased signal attenuation and bit error rate (BER) are major hurdles to system performance at THz frequencies. MIMO antenna diversity techniques at the RF front end can significantly improve system performance. Toward this aim, this work attempts to develop a new THz-MIMO antenna system for future wireless applications. The proposed antenna uses a modified version of a traditional rectangular patch as the radiating element. The combination of a co-planar waveguide (CPW) feed structure and a modified stair-case radiator with an inverted L-shaped arch achieves excellent impedance matching between the feed line and the radiator, resulting in a broad bandwidth in the THz range. To evaluate the diversity performance of the antenna, both spatial and orthogonal 2-port antenna systems are designed and analyzed. Furthermore, isolation is enhanced by placing a frequency-selective surface (FSS) between the radiators of the proposed 4-port antenna. This design offers dual bandwidth, covering the ranges of 2.3–2.7 THz and 5.5–8.9 THz. The proposed antenna achieves very low mutual coupling (less than −30 dB), an extremely low envelope correlation coefficient (ECC) of 0.00001, and a low channel capacity loss (CCL) of 0.1 bps/Hz.

CMOS Voltage-Controlled Oscillator with Complementary and Adaptive Overdrive Voltage Control Structures

This paper displays a voltage-controlled oscillator (VCO) with high performance implemented in 0.18 µm CMOS. The proposed CMOS VCO adopts a current-reused method, analog coarse and fine tuning mechanisms, and an adaptive overdrive voltage control structure to increase the overall performance, such as the power dissipation, phase noise, and tuning range, and has a robust start-up condition. The current-reused complementary structure with higher transistor transconductances is to save power consumption; the analog coarse and fine tuning mechanisms are to effectively widen the tuning range; and the adaptive overdrive voltage control technique is to change the transconductances of the transistors to improve power consumption by reasonably biasing the gate and body terminals in a class-AB mode to adjust the threshold voltage of the NMOS transistors. The proposed CMOS VCO adopts the class-AB mode to improve the overall performance and the start-up condition. The figure-of-merit (FOM) and FOM with tuning range (FOMT) are used in evaluating the CMOS VCO performance. The measured phase noise at 1 MHz and 10 MHz offsets is –130.34 dBc/Hz and –150.96 dBc/Hz at the 3.38 GHz operating frequency, respectively. The proposed CMOS VCO has a tuning range between 2.85 and 3.62 GHz corresponding to 23.8% for the fifth-generation (5G) wireless communication applications. The proposed CMOS VCO core using a 1.4-V supply consumes 7.5 mW DC power. The FOMs and FOMTs at 1- and 10-MHz offsets are −192.2, −192.8, −199.7, and −200.3 dBc/Hz, respectively, from the 3.38 GHz output frequency.

Triboelectric Nanogenerator‐Enabled 3D Microporous Polydimethylsiloxane–Graphene Oxide Nanocomposite for Flexible Self‐Powered Humidity Sensing Applications

The imperative to meet the energy needs of contemporary electronic devices has spurred extensive exploration into self‐powered systems. Given the anticipated ubiquity of sensor networks in future cities, a novel battery‐free sensing paradigm, rooted in triboelectric nanogenerators (TENG), has gained prominence. Utilizing mechanical energy otherwise wasted daily for electricity generation presents a promising alternative to conventional sensors. Embedding the sensing electrode within the TENG structure enables the creation of gas sensors suitable for portable and wireless applications. This study focuses on fabricating a 3D microporous sponge of polydimethylsiloxane (PDMS) using sugar cubes and graphene oxide (GO) nanosheets. Leveraging the hydrophilic properties of the GO enhances moisture absorption, elevating the humidity sensor's responsivity. In addition, the porous structure not only improves sensitivity to high humidity but also mitigates surface saturation issues prevalent in nonporous sensors. The porous self‐powered sensor, composed of PDMS with 0.5 wt% of GO, exhibits a response of up to 2500%, quantified as ((ΔV/V) × 100%), to relative humidity changes from 20% to 99%. Furthermore, the response and recovery times stand at 1.2 and 2.3 s, respectively. These findings underscore the feasibility of integrating TENG electrodes, utilizing a porous PDMS–GO nanocomposite, to create various types of integrated gas sensors.

Flexible and stretchable polyester@reduced graphene oxide composite fabric for tunable electromagnetic absorption

The widespread application of 5 G wireless communication and flexible electronic devices has put forward new demands for electromagnetic (EM) absorbing materials. In this work, a flexible composite fabric was successfully prepared by using polyester (PET) knitted fabric as an elastic scaffold and subsequently anchoring reduced graphene oxide (rGO) through a simple impregnation-drying coating method. Regulating the concentration of graphene oxide (GO) impregnation solution can effectively control the rGO loading content for adjusting the EM parameters of PET@rGO composite fabric. When the concentration is 2.0 mg/mL, the as-prepared PET@rGO exhibits the optimum reflection loss (RL) value of −24.53 dB at 12.4 GHz and a corresponding effective absorption bandwidth (EAB, RL≤−10 dB) of 3.20 GHz (9.20–12.40 GHz). The impressive absorption property attributed to the synergistic effect of impedance matching and dielectric loss originated from the three-dimensional (3D) conductive network on fabric interlaced structures. More importantly, stretching PET@rGO composite fabrics to different deformations can dynamically adjust the EM absorption properties while maintaining the knitted structure. This work demonstrates an efficient avenue for the rational design of next-generation EM absorbing fabric, showing latent applications in flexible functional electronics.

Software Platform for the Comprehensive Testing of Transmission Protocols Developed in GNU Radio

With the constant growth of software-defined radio (SDR) technologies in fields related to wireless communications, the need for efficient ways of testing and evaluating the physical-layer (PHY) protocols developed for these technologies in real-life traffic scenarios has become more critical. This paper proposes a software testbed that enhances the creation of network environments that allow GNU radio applications to be fed with test traffic in a simple way and through an interoperable interface. This makes the use of any traffic generator possible—existing ones or one that is custom-built—to evaluate a GNU radio application. In addition, this paper proposes an efficient way to collect PHY-specific monitoring data to improve the performance of the critical components of the message delivery path by employing the protocol buffers library. This study considers the entire testing and evaluation ecosystem and demonstrates how PHY-specific monitoring information is collected, handled, stored, and processed as time series to allow complex visualization and real-time monitoring.

Switchable and multifunctional terahertz photonic devices based on VO2-assisted phase encoded metasurfaces

Metasurfaces, especially coded ones, have gained significant attention for their excellent ability to control electromagnetic (EM) waves, opening up possibilities for a new generation of miniaturized devices. However, integrating multiple functionalities into a single metasurface while endowing tunable performance remains a challenge. In this study, we propose a strategy to design switchable and multifunctional terahertz (THz) photonic devices using complementary Gold-VO2 split resonant ring (GV-SRR) and complementary Gold-VO2 split resonant oblong (GV-SRO) structures. The designed devices can convert right-handed circularly polarized (RCP) light into left-handed circularly polarized (LCP) light in three frequency bands, corresponding to center frequencies fre.1 = 0.34 THz (narrowband), fre.2 = 0.50 THz (narrowband), and fre.3 = 0.80 THz (broadband). The phases of the reflected LCP wave can be independently modulated across different frequency bands by rotating the in-plane orientation of GV-SRR and GV-SRO separately. In addition, the overall phase reconstruction can be achieved through the state change of VO2. By arranging GV-SRR and GV-SRO in a defined encoding form, the engineered photonic devices can exhibit distinct and switchable capabilities in modulating EM wavefronts across various frequency ranges. As proof-of-concept examples, we have designed three encoded photonic devices, namely, a dynamic beam splitter (DBS), an achromatic and zoom metalens (AZM), and a switchable device between metalens and focusing orbital angular momentum (OAM) generator (MFOAM). These devices have potential applications in wireless communication, AR holographic displays, and information processing.

Investigation effect of Lu-substitution on structural, morphological, magnetic, and dielectric properties of BaM hexaferrite synthesized using a co-precipitation method

In this paper, we synthesized Lu-substituted M-type barium ferrites (BaLuxFe12-xO19, x = 0, 0.2, 0.4, 0.6, 0.8) by chemical co-precipitation using a non-stoichiometric ratio of raw materials. We investigated their structure, XPS, and EDX spectra, morphology, and magnetic and dielectric properties. The XRD patterns showed that the diffraction peaks shifted toward a lower angle and the lattice constant ratio (c/a) was less than 3.98, which was within the allowable range of magneto-plumbite structure. XPS and EDX spectra confirmed the presence of O, Fe, Ba, and Lu elements in the samples. SEM images revealed that the ceramic samples sintered at 1330 °C had a regular and obvious hexagonal structure. Lu substitution promoted grain growth, with an average grain size increase of 163% and a maximum grain size of 21.77 µm. Hysteresis loops indicated the formation of a multi-domain structure in the samples. The coercivity decreased from 2035.82 Oe to 574.84 Oe and the saturation magnetization decreased as well but still exceeded 58 emu/g. The dielectric constants of all the samples were in the order of 103 to 104 and the substitution of Lu significantly increased it to about 16k. The tangent loss could be maintained below 0.5, with a minimum of approximately 0.1. The Lu-substitution barium ferrites with high saturation magnetization, low coercivity, high dielectric constant, and low tangent loss coexistence may be a potential candidate for application in low-frequency wireless communication with miniaturization and multifunction.

New Stable Gallium(III) and Indium(III) Complexes with Thiosemicarbazone Ligands: A Biological Evaluation.

The aim of this work is to explore a new library of coordination compounds for medicinal applications. Gallium is known for its various applications in this field. Presently, indium is not particularly important in medicine, but it shares a lot of chemical traits with its above-mentioned lighter companion, gallium, and is also used in radio imaging. These metals are combined with thiosemicarbazones, ligating compounds increasingly known for their biological and pharmaceutical applications. In particular, the few ligands chosen to interact with these hard metal ions share the ideal affinity for a high charge density. Therefore, in this work we describe the synthesis and the characterization of the resulting coordination compounds. The yields of the reactions vary from a minimum of 21% to a maximum of 82%, using a fast and easy procedure. Nuclear Magnetic Resonance (NMR) and Infra Red (IR) spectroscopy, mass spectrometry, elemental analysis, and X-ray Diffraction (XRD) confirm the formation of stable compounds in all cases and a ligand-to-metal 2:1 stoichiometry with both cations. In addition, we further investigated their chemical and biological characteristics, via UV-visible titrations, stability tests, and cytotoxicity and antibiotic assays. The results confirm a strong stability in all explored conditions, which suggests that these compounds are more suitable for radio imaging applications rather than for antitumoral or antimicrobic ones.

Shared-radiator design of broadband and dual-mode antenna for personal role radio applications

Abstract Shared-radiator design of a broadband and dual-mode antenna that simultaneously covers the VHF/UHF band and satellite navigation band is presented for personal role radio (PRR) applications. Quadrifilar helix antenna (QHA) is devised to be a circularly polarized radiator which as well acts as a part of the upper half radiation arm of the dipole antenna and be equivalent to a linearly polarized radiation current carrier at VHF/UHF band, forming a symmetrical dipole antenna with a sinusoidal current distribution. A 5th-order balanced matching network comprised of five cascade L-sections is adopted to obtain the maximum possible working band-width and a 3.76:1 band-width (116 %) at VHF/UHF band is achieved. Strong mutual coupling effect of the two operating modes is observed near 1.5 GHz originated from QHA shared-radiator design, and a new balun structure is applied to achieve high isolation and self-decoupling, subsequently |S21| of the two operating modes is significantly reduced from about −18 dB to below −32 dB at satellite navigation band without affecting the reflection coefficient and radiation efficiency. The measured results show that radiation patterns of the manufactured prototype is basically consistent with corresponding simulation counterparts.

AN ORGANISED AND FOCUSED REVIEW OF A MICROSTRIP PATCH ANTENNA FOR ITS DEPLOYMENT IN BIOMEDICAL APPLICATIONS

Reviewing microstrip antennas for diverse applications is the goal of this paper. The designing of microstrip patch antennae is a new study subject established for utilise in 5th generation communications applications. An antenna is a group of interconnected devices that work together to transmit and receive radio waves as a single antenna. Antennas come in many sizes and shapes. An antenna design that is low profile, lightweight, and results-oriented is the microstrip patch. In the future, microstrip patch antenna may be used for various 6G communication systems applications. Furthermore, 6G communication applications can be developed for additional devices, such as autonomous cars, machine learning, artificial neural network algorithms, radar, internet of things (IoT), biomedical, and vehicle-to-vehicle (V2V) communication. In the past, 4G wireless applications employed the multiple input, numerous output (MIMO) pattern as a standard geometry. This study covers several types of antennas, their geometric structures, different methods for analyzing their features, and their dimensions. The component of the substrate substances, loss tangent, the thickness, return loss, bandwidth, voltage-standing-wave ratio (VSWR), gain, and orientation from the earlier publications will also be covered. Keywords – microstrip, patch, antenna, IoT, biomedical, V2V, MIMO, VSWR

Radio resource management Satellite Communication Networks MCDM Method

A communications satellite would be an artificial satellite that creates a channel here for the transmission of a communication through a transponder between a sender and a recipient located at various locations on Earth. Communications via satellite are used in telecommunications, radio, broadcast, computer, and military applications. Satellites offer three different kinds of communication services: data communication, broadcasting, and telephone. Lower Geostationary satellite, Networks for Low-Earth-orbiting (LEO) and Medium Eccentricity Orbit (MEO) are the three different types of satellite networks. A satellite system or a portion of a satellite system with only one satellite in it and a working ground station is known as a satellite network. Models 1, 2, and 3. A satellite network is a system that uses satellite technology to transmit media services to recipients. The two main components of communication systems are the ground component, which consists of stationary or mobility transmissions, receptions, and ancillary equipment, and indeed the space component, which primarily consists of the satellite. In addition to offering in-flight communications, satellites are frequently the primary voice communication method in rural areas and places where telephone connections have been disrupted during a catastrophe. Satellites are also a major source of time for cell phones and pagers. With nine operating communications satellites in geo-stationary orbit, one of the largest domestic satellite communications networks in the Asia-Pacific region is the Indian National Television (INSAT) system. Radio and cable television are provided to us. They allow us to use our mobile phones to make long distance calls. So that we can find ourselves and get directions, they offer us the Global Positioning System (GPS) our destinations. Satellites offer data on Earth's atmosphere, seas, land, and clouds. They can also see smoke, volcanoes, and forest fires. All of this data aids in weather and climate prediction. Farmers benefit from knowing what crops to plant. PROMETHEE (Priority Ranking System Method for Enrichment Assessments) About PROMETHEE methods and usage to uncover current research to classify and explain A classification scheme and a comprehensive literature review is presented. Alternative is Laser communication, optical networks, satellite optical communication, vibrations and satellite network. Evaluation parameters are Solar Radiation Pressure, Thermal Bending, Micro Meteorite impacts, Solar and Lunar Gravity and Earth oblations effects. Vibrations are got the first rank whereas is the Optical networks are having the Lowest rank. Satellite Communication Networks for using the analysis of PROMETHEE Method. Vibrations is got the first rank whereas is the Optical networks is having the Lowest rank.

A compact dual-feed wide-band slotted antenna for future wireless applications

A compact dual-feed wide-band slotted antenna for future wireless applications

Semi-Supervised Learning-Enhanced Fingerprint Indoor Positioning by Exploiting an Adapted Mean Teacher Model

Location awareness is crucial for numerous emerging wireless indoor applications. Deep learning algorithms have demonstrated the potential for achieving the required level of positioning accuracy in indoor environments. However, obtaining abundant labels for data-driven machine learning is costly in practical situations. As an effective solution to alleviating the insufficiency of labeled data for deep learning-based indoor positioning, deep semi-supervised learning (DSSL) can be employed to lessen the dependency on labeled data by exploiting potential patterns in unlabeled samples. In this paper, we propose an Adapted Mean Teacher (AMT) model within the DSSL paradigm for indoor fingerprint positioning by using a channel impulse response. To enhance the generalization of the trained model, we design an efficient implicit augmentation scheme for the training process in the AMT model. Furthermore, we develop a tailored residual network to efficiently extract location characteristics in the AMT framework. We conduct extensive simulation experiments for indoor scenarios with heavy non-line-of-sight conditions based on open datasets to demonstrate the effectiveness of our proposed AMT model. Numerical results indicate that the AMT model outperforms several consistency regularization methods and the pseudo-label method in terms of positioning accuracy and lower positioning latency, achieving a mean error of 90cm when using a small number of labels.

Shuffled frog Leaping algorithm based circular patterns loaded ring shaped fractal antenna for multistandard wireless applications

This paper describes the design and experimental behavior of a 2nd iterated modified Square Ring Shaped Fractal Antenna (SRSFA). The radiator geometry consists of three symmetrical square-shaped rings loaded with circular patterns at the corners. The designed fractal patch is placed on a slot loaded ground structure. The electrical dimensions possessed by the realized structure are 0.15λ0 x 0.15λ0 x 0.080 λ0, and the whole antenna is implemented using FR4 substrate. In this design, transmission line width ‘WF’ and position ‘FP’ are optimized using Shuffled Frog Leaping Algorithm (SFLA) and Artificial Bee Colony (ABC) strategies. It has been examined that the optimized values of ‘WF’ and ‘FP’ using SFLA and ABC are 2.6 and 12.4 mm, and 3.2 and 15.9 mm, respectively. Results reveal that SFLA offers better solution quality and convergence speed than ABC. Further, experimental analysis has been demonstrated to effectively illustrate the recommended fractal approach. The equivalent circuit of the designed structure is implemented successfully. The conducted measurements show that for VSWR ≤ 2, the fabricated structure produces six resonance points with adorable S11 values. The resonances appear at 1.53 GHz (1.35–1.67 GHz), 4.30 GHz (4.20–4.40 GHz), 7.58 GHz (7.43–7.70 GHz), 11.35 GHz (10.37–11.58 GHz), 14.03 GHz (13.85–14.35 GHz), and 15.93 GHz (15.43–16.25 GHz). The examined −10 dB impedance bandwidth at the respective resonance points is 20.9 %, 4.6 %, 3.5 %, 11.3 %, 2.9 %, and 5.23 %. Healthy concordance is noticed among the experimental measurements and electromagnetic simulations. The demonstrated radiation patterns are arbitrary bidirectional/omnidirectional at the respective resonances with good stability. Additionally, the offered gain is within the range of 4.91–7.00 dB. Hence, by utilizing the above-mentioned approaches, miniaturization of 65 % has been achieved. Practical outcomes suggest that the introduced prototype exhibiting multiband behavior, can be effectively applied in Radio location, Radio astronomy, Long-range tracking, Weather location Broadcasting, Search for extra-terrestrial intelligence, Radar altimeters, High resolution mapping, Aeronavigation, and Miscellaneous Radars.

Optimization Techniques in Cooperative and Distributed MAC Protocols

The tremendous increase in wireless network application finds distributed allocation of resources allocation very useful in the network. Packet delivery ratio and delay can be improved by concentrating on payload size, mobility, and density of nodes in the network. In this article, a survey is carried out on different cooperative and distributed MAC protocols for communication and optimization algorithms for various applications and the mathematical issues related to game theory optimizations in MAC protocol. Spatial reuse of channel improved by (3-29) % and multi-channel improves throughput by 8% using distributed MAC protocol. The energy utility of individual players can be focused to get better network performance with NASH equilibrium. Fuzzy logic improves channel selection by 17% and secondary users' involvement by 8%. Jamming, interference problems can be addressed using cross layer approach in the MAC and simultaneous data, voice transmissions in IoT; WSN applications can be attained using hybrid distributed MAC protocol.

Implementation of highly isolation OLR: based microstrip full-duplex Tx/Rx antenna systems with low insertion loss for contemporary wireless system applications

This paper presents a Highly Isolation open-loop resonators (OLR)—based microstrip full-duplex Tx/Rx antenna systems with low insertion loss for contemporary wireless system applications. Through a T-junction combiner, the proposed diplexer is accomplished by combining two OLR—based band-pass filters tuned at two distinct frequencies. The system is implemented on a Rogers TMM4 substrate with a loss tangent of 0.002, a dielectric constant of 4.7, and a thickness of 1.52 mm. The suggested full duplex has dimensions of (90 × 70) mm2. It achieves a modest frequency space ratio of R = 0.1646 in both transmit and receive modes by having two resonance frequencies of {f}_{t} = 2.191 GHz and {f}_{r} = 2.584 GHz, respectively. The simulated structure displays good insertion losses (IL) of approximately 1.2 dB and 1.79 dB for the two channels, respectively, at fractional bandwidths of 1.24% at 2.191 GHz and 0.636% at 2.584 GHz. The simulated isolation values for 2.191 GHz and 2.584 GHz are 53.3 dB and 66.5 dB, respectively.

Design and implementation of hybrid fed array antennae for Sub-6 GHz and 5G mm-wave communication and wireless applications

Abstract This paper proposes fractal-inspired array antennae for wideband applications. The proposed antennae have a resonance frequency range of 20–40 GHz. The modified fractal antennae are fabricated with a height of 1.6 mm, substrate width, and length of 100, 50, 25, and 18.75 mm2, and a simulated result shows that the gain is increased to 11.04, 11.9, 8.4, and 6 dBi, and the designed antennae radiate power with directivity of 11.3, 13.4, 9.29, and 7.17 dBi concerning proposed designs A, B, C, and D, respectively. The proposed antennae with 5G New Radio (NR) bands have more radiation concerning resonate frequencies in the 20–40 GHz range with Φ = 0°, Φ = 90°, and θ = 90°. Moreover, the bandwidths for applications covered in the 5G NR and sub-6G are 1.92, 0.73, 0.7, 2.4, 1.3, 5.3, and 1.26 GHz, and 3.4, 3.7, 2.67, and 4.65 GHz, and 2, 3.5, and 1.57 GHz, and 2.5, 1.5, and 1.0 GHz with the maximum return loss of 37 dB, 32.8 dB, 31.2 dB, and 23 dB with corresponding resonate frequencies as 21.5, 27.6, 33, and 27.6 GHz concerning designs A, B, C, and D, respectively. The proposed antennae have been implemented and validated using Computer Simulation Technology (CST), Vector Network Analyzer (VNA), spectrum analyzer, and power sensor.

A miniaturized dual L shaped with truncated ground rectangular monopole antenna for 5G and wireless communications

This paper presents the design and analysis of a miniaturized dual L-shaped inverted to each other dual-band monopole antenna intended for 5G and wireless communication applications. The proposed antenna, with compact dimensions of 20×20×1.6 mm³, operates in two frequency bands (3.2-3.6 GHz)/3.5GHz and (6.0-6.6 GHz)/6.5GHz. These frequency bands are critical for 5G technology, ensuring high-speed data transfer and improved network efficiency. The antenna achieves bandwidths of 11.7% and 9.3% for the lower and upper bands, respectively, offering robust performance and adaptability in diverse wireless communication scenarios. The design employs a dual L shape inverted to each other configuration with truncated L shaped ground plane to achieve the desired miniaturization and dual-band functionality. The antenna's performance metrics, including return loss, gain, and radiation patterns, demonstrate its suitability for integration into compact wireless devices, thereby advancing the development of efficient and space-saving 5G communication systems.

A centre C-shaped dual band rectangular monopole antenna for Wi-Fi and wireless communication

This paper presents the design and analysis of a center C-shaped dual-band rectangular monopole antenna optimized for Wi-Fi and wireless communication applications. The proposed antenna operates efficiently within the frequency ranges of 1.4-1.8 GHz and 5.2-5.8 GHz, targeting dual-band functionality. The proposed antenna has achieved dual band because it has a rectangular ring with C-shaped cutting on the patch antenna. The compact dimensions of 39 × 50 × 1.6 mm³ designed on FR4 electrodes having a dielectric constant of 4.4 make it suitable for integration into modern wireless devices. The antenna achieves a bandwidth of 10.9% and 25% in the respective frequency bands as a result of the C-shaped resonating cavity. Simulated results demonstrate the antenna's capability to maintain stable gain and omnidirectional radiation patterns across the desired frequencies. The versatility and compactness of this monopole antenna make it an ideal candidate for next-generation Wi-Fi and wireless communication systems.