Type Of Antenna Research Articles

English

Cell phones and mobile devices have been an integral part of life over the past 30 years. In parallel with the intensity of use of mobile phones, the number of base stations has also increased. The increasing number of base stations has caused an intensity of electromagnetic pollution in the GSM band. The issue of electromagnetic pollution has become increasingly remarkable due to the claims that it can cause diseases and scientific studies carried out in this field. The number and variety of studies carried out in the last 30 years in this regard has also increased. Base stations are established with various features. While some kinds of base stations use radial antenna type, some of them use directional antennas. Depending on the region where it is established, the cell types it uses may also differ. Therefore, multiple measurements are required to analyse the impact of a base station. However, it is practically not possible to make an infinite number of measurements. Within the scope of this study, it is aimed to refine and clarify the electromagnetic pollution maps by using artificial intelligence methods. As a result of the studies carried out in this area, electromagnetic pollution maps have become much more detailed. Key words: Electromagnetic pollution, GSM, base station.

Clogging evaluation of porous asphalt pavement using ground-penetrating radar

Clogging reduces the porosity of porous asphalt (PA) pavement, which would jeopardize its permeability, noise absorption, and skid resistance. Existing evaluating methods use in-situ cores that damage the pavement with limited coverage. This study explored the feasibility of evaluating PA pavement clogging using ground-penetrating radar (GPR). Laboratory tests were performed on porous asphalt (PA) slabs under various clogging degrees. The effect of antenna type and moisture on clogging evaluation were investigated. The performances of two clogging indicators were examined, including the bulk dielectric constant obtained using the time-of-flight method and time–frequency spectrograms using the short-time Fourier transform (STFT). Effectiveness of GPR-based clogging evaluation was validated by permeability tests. Results show that both indicators could effectively evaluate clogging in PA pavement. The effectivenesses of proposed indicators were verified through permeability tests. GPR surveys are suggested 72 h after rainfall in sunny days using 2 GHz air-coupled antennas.

Analysis of Characteristics for Inter-System Bias on Multi-GNSS Undifferenced and Uncombined Precise Point Positioning

Multi Global Navigation Satellite System (GNSS) Precise Point Positioning (PPP) has become the mainstream of PPP technology. Due to the differences in the coordinates and time references of each GNSS, multi-GNSS PPP must include additional Inter-System Bias (ISB) parameters to ensure compatibility between different GNSSs. Therefore, research on the characteristics of ISB is also essential. To analyze the short- and long-term time characteristics of multi-GNSS ISBs, as well as their relationship with receiver type and receiver antenna type, the Undifferenced and Uncombined (UDUC) PPP model of Global Positioning System (GPS), BeiDou navigation satellite system (BDS), and Galileo satellite navigation system (Galileo) was rigorously derived, and the physical of ISBs was elaborated in depth. ISB parameters were estimated and analyzed using 31 days of data from the 31 Multi-GNSS Experimental stations (MGEX). The results indicate that: (1) the ISB value is dependent on the station receiver type, receiver antenna type, analysis center product utilized, and GNSS system. (2) The short-term time characteristics of ISB-COM, ISB-WUM, and ISB-GBM are similar for the same station but not for the long term. In addition, ISBs are more stable in the short term. (3) There is little correlation between the ISB time characteristics, the receiver type, and the receiver antenna type, and the day-boundary discontinuity(DBD) on the ISB can be ignored for the concussive days’ process.

On Modeling Antennas Using MoM-Based Algorithms: Wire-Grid versus Surface Triangulation

This paper focuses on antenna modeling using wire-grid and surface triangulation as two of the most commonly used MoM-based approaches in this field. A comprehensive overview is provided for each of them, including their history, applications, and limitations. The mathematical background of these approaches is briefly presented. Two working algorithms were developed and described in detail, along with their implementations using acceleration techniques. The wire-grid-based algorithm enables modeling of arbitrary antenna solid structures using their equivalent grid of wires according to a specific modeling recommendation proposed in earlier work. On the other hand, the surface triangulation-based algorithm enables calculation of antenna characteristics using a novel excitation source model. Additionally, a new mesh generator based on the combined use of the considered algorithms is developed. These algorithms were used to estimate the characteristics of several antenna types with different levels of complexity. The algorithms computational complexities were also obtained. The results obtained using these algorithms were compared with those obtained using the finite difference time domain numerical method, as well as those calculated analytically and measured. The analysis and comparisons were performed on the example of a rectangle spiral, a spiral, rounded bow-tie planar antennas, biconical, and horn antennas. Furthermore, the validity of the proposed algorithms is verified using the Monte Carlo methodology.

Impact of Antenna Design, Electromagnetic Propagation, and RF Frequency on the Performance of Wireless Communication Systems in Urban Environments

The design and optimization of antennas, electromagnetic propagation, radio frequency (RF), and channel characterization are vital to the performance of the system in the rapidly developing area of wireless communication. Antennas are electronic components that transform electrical currents into electromagnetic waves and vice versa. They are critical to the operation of any wireless network and their design and optimization are therefore of paramount importance. The goal of this research was to find out how different factors, like antenna type, electromagnetic environment, RF, and channel characteristics, affect the efficiency of a wireless network. Multipath fading of 8 dB, shadow fading of 3 dB, and path loss of 100 dB were used in the study with a microstrip antenna in a suburban propagation scenario at an RF frequency of 5 GHz. Antenna design, electromagnetic propagation scenario, radio frequency (RF), and channel characteristics were all shown to have an impact on the wireless communication system performance. The performance metrics of the wireless sensor network were almost, but not quite, those that were hoped for in a real-world setting. Several avenues for future study are suggested, and the results have important implications for the design and optimization of wireless communication systems.

Design of UAV Antennas and Challenges: Review

In the last decade, researchers have been attracted by the drone and its antenna design. Few years back, drone was used only for surveillance but now drone is using in various filed i.e., weather forecasting, transportation, communication, search & rescue etc. Antennas are the most important part of drone or UAV. Designing of antennas for drone is the challenging task for the researchers without increasing the overall weight of drone. In this article, classification of drone as per their weight, altitude and applications, different types of antennas have been discussed with its challenge. Different antenna design has been discussed and compared with different parameters.

Snipped Triple Band Microstrip Antenna for ISM Band and Wi-MAX Applications

The work suggests a snipped shaped patch antenna design and its analysis which will work in the microwave frequency in the low spectrum. Here the patch is introduced which is made up of denim cotton material. This type of antenna is relatively new device used for medical applications. This antenna is light in weight, compact in size, and inexpensive. This antenna resonates at 1.18 GHz, 2.45 GHz, 3.1 GHz, and 7.9 GHz to 10.6 GHz. As a result, it is used in Industrial Scientific and Medical (ISM) band and Wi-MAX applications. There are different types of patch antenna here a microstrip is used as wearable antenna. As a result, the patient’s condition can be diagnosed by using this antenna after studying the radiation pattern, return loss. Ansoft HFSS can be used to emulate them.

Design a Dual Polarizations MIMO Antenna Based on Decoupling Elements for 5G Smart-Phones

This paper suggests a compact linear and circular polarization MIMO antenna for sub-6 GHz 5G smartphones. The proposed design can be divided into three parts: Firstly, a linear polarized dipole antenna is presented with dimensions of 1×33.7×32.5mm3 and exhibits an impedance bandwidth (IBW) of 3.24GHz ranging from 3.3GHz to 6.6GHz at S11˂-10dB. The second part includes a circular polarization CPW-Fed antenna with dimensions of 1×23.2×30mm3. The IBW of the CPW antenna is more than 4GHz, starting from 3.9GHz to more than 8GHz at an S11˂-10dB. The 3-dB axial ratio for the CP CPW antenna ranges from 4GHz to 7.38GHz. Finally, a combination of LP and CP antennas is presented to form a dual polarization MIMO system. A MIMO system consists of 5 elements; 4 elements are LP and 1 element is a CP antenna. The size of the MIMO system is 1×82.5×150mm3 printed on an FR-4 substrate. Two impedance bandwidths are found due to the use of two antenna types. The first one (S11, S22, S44, S55) equals 3.44GHz while the second (S33) equals 4.33GHz. HFSS is used for designing and simulating the proposed structures, while CST is used for verifying the results.

Metasurface cloaks for decoupling electromagnetic interference within highly dense areas

This paper presents the results of intensive investigations of electromagnetic interference caused primarily by closely arranged antennas within subwavelength distance; potential applications involve the principle of scattering cancellation. A cloaked planar monopole antenna (CPMA) is newly proposed in this work. The performance of the CPMA is compared with that of a bare planar monopole antenna. Numerical simulations with the two antenna types were conducted, and various configurations with the potential for practical applications in the industrial and defense sectors were tested.

Diversity Glass Antennas for Tri-Band WiFi Applications

This paper investigates two novel polarization- and pattern-diversity glass dielectric resonator antennas (DRAs), both of which are for tri-band (2.4, 5.2, and 5.8 GHz) wireless fidelity (WiFi) applications. It also investigates what type of diversity antenna is most suitable for WiFi router applications by comparing the two DRAs, along with a new space-diversity glass DRA. These three diversity glass DRAs are also compared with a commercial space-diversity monopole pair to benchmark the performance of the glass DRA in WiFi router applications. In our polarization-diversity antenna, a double-port feeding scheme is developed to excite different DRA modes. The frequencies of the DRA modes are tuned by using a stepped DRA. For the pattern-diversity design, a stacked DRA is introduced to broaden the bandwidth for both the conical and broadside radiation modes. All three of the new diversity antennas were fabricated and measured to verify the simulations. In our experiment, the bit error rate (BER) of the three diversity glass antennas and the reference space-diversity monopole antenna was also measured, and the results are compared and discussed. It is found that the polarization-diversity omnidirectional DRA has the most stable BER among the three.

Rekabentuk dan Prestasi Antena MEMS Penuai Tenaga Mikro Frekuensi Radio Bagi Peranti Elektronik Berkuasa Rendah

Radio Frequency (RF) ambient energy has become the choice as a source of green energy for energy harvesting systems due to the existence of electromagnetic wave signals that are always present in the environment without incurring cost. This RF energy is very low usually less than 190 µW. However, the antenna needs to supply sufficient power to the RF energy harvesting system to power low-power electronic devices. Therefore, the antenna needs to be designed to capture and transfer energy to the RF micro energy harvesting circuit to supply optimal power to the electronic device. The micro-strip antenna design using Micro Electro Mechanical (MEMS) fabrication technology process is the most suitable choice because of its small size, light weight and high performance. This MEMS antenna design uses Computer Simulation TechnologyMicrowave-Studio software(CST-MWS). Comparisons were made for four types of antennas namely silicon surface micromachine, silicon bulk micro-machine with air cavity, glass surface micro-machine and RT/Duroid 5880 as reference. The simulation results show that the glass surface micro-machine antenna is the smallest in size compared to the other three antennas. The return loss of this antenna is also better which is increased by 55.1% and 5.6% compared to silicon surface micro-machine antennas and conventional RT/Duroid antennas respectively. The antenna also has a large bandwidth of 117 MHz, a gain of more than 5 dB and a direction of more than 5 dBi. The glass surface micro-machine antenna has been successfully fabricated using MEMS technology which produces a transparent antenna measuring (L/W) 19 mm x 19 mm. This small sized MEMS antenna is highly sensitive and highly effective for capturing ambient RF signals and is capable of supplying sufficient power to the RF energy harvester system.

Parachute shape ultra‐wideband wearable antenna for remote health care monitoring

SummaryWireless body area networks (WBAN) is used to measure patients' health conditions continuously. Different kinds of sensors are required to measure health conditions. When such types of antennas are used on the human body, they are flexible with the movements. The usage of wearable devices is currently increasing in the biomedical field. The presented wearable antenna is suitable for biomedical applications. The presented ultra‐wideband (UWB) flexible parachute shape wearable antenna is fabricated on a jeans textile substrate. The prototype antenna has a −10 dB measured impedance bandwidth of 5800 MHz (7 to 12.8 GHz) with average radiation efficiency of 75.28%. The prototype antenna's size is 40 × 40 mm2 (1.32 × 1.32 at centre frequency 9.9 GHz) and a peak gain of 4.5 dB at 12.33 GHz. The fabricated antenna is suitable for biomedical applications in X‐band frequencies and can be implemented with a low‐cost manufacturing process. The radiating element is made by conductive copper tape. Muscle‐equivalent phantoms are used to analyze the body effect on antenna performance. The radiation effect emitted by the presented antenna on the human body is calculated by the specific absorption rate (SAR) value. The maximum SAR value of the proposed antenna is 1.84 W/kg at 12.33 GHz. This leads to promising results for wearable applications related to remote health care monitoring, such as biotelemetry and mobile health with a sensor‐driven approach.

Analysis of a Low-Earth Orbit Satellite Downlink Considering Antenna Radiation Patterns and Space Environment in Interference Situations

This paper investigates a low-Earth orbit (LEO) satellite downlink for high-speed data communication in interference situations. A choke ring horn type antenna is used as the data transmitting antenna with an isoflux pattern in the LEO satellite, which has a beam coverage of ±51.6° and a bore-sight gain of 4.4 dBi at 8 GHz. The receiving antenna on the ground station is a parabolic type antenna with a diameter of 11.3 m, and it has a half-power beam width (HPBW) of 0.2° with a maximum gain of 59 dBi at 8 GHz. The jamming-to-signal ratio (J/S) is calculated assuming that the LEO satellite transmits signals to the ground station, and an elevation angle of the interference source varies from 0° to 90° at an altitude of 10 km. Applying antenna characteristics, such as HPBWs and side lobes, to the calculated space wave path loss makes it possible to predict the J/S results according to the location of the interference source and the satellite. The results show that it is necessary to consider the space environment to accurately analyze the LEO satellite downlink, especially at the low elevation angle of the satellite.

The Residual Stress Relief and Deformation Control of Al Alloy Thin-Walled Antenna Components by Ultrasonic Regulation

The residual stress fields of the initial billet and subsequent machining in the material bring great challenges to the precision machining and geometrical stability of aluminum alloy thin-walled components. To ensure that a certain type of large-sized aluminum alloy thin-walled antenna has a small flatness deformation during forming, this paper firstly employed the ultrasonic critical refraction longitudinal wave (LCR wave) detection method to measure the different depth ranges’ residual stress distribution of 5A06/6061/7075 aluminum alloy plate, both as blanks and after multiple milling. Additionally, the effects of inherent residual stress (IRS) and machining-induced residual stress (MIRS) on the subsequent milling deformation were analyzed. After that, combined with the self-developed ultrasonic stress relief (USR) system, the deformation control effect of a thin-walled plate after eliminating residual stress in each stage was tested. The results show that the ultrasonic stress relief treatment can quickly and efficiently eliminate the IRS and MIRS with small flatness deformation. By introducing the URS treatment in the blank, rough machining, and semi-finishing stages, the components before each subsequent machining are in a low-stress state, and the component deformation can be gradually controlled so that the final thin-walled antenna has a smaller flatness.

Guard band protection for coexistence of 5G base stations and satellite earth stations

In this paper, the coexistence between fifth generation (5G) network and fixed satellite service (FSS) is investigated. To reduce the interference between 5G base stations (BSs) and FSS earth station (ES), a guard band protection method is proposed. Additionally, the distance and angular protection methods are amalgamated. The performances are evaluated by simulation in realistic 3GPP. Also, the impacts of four antenna types are analysed for a 5G BS. The numerical results show that the guard band protection can solve the interference for the 5G/FSS coexistence, when the distance protection is combined. In addition, when the hybrid protection method is employed, the coexistence between 5G BS and FSS ES is guaranteed.

A Novel Dual-Permanent-Magnet Mechanical Antenna for Pipeline Robot Localization and Communication

The demand for pipeline inspection has promoted the development of pipeline robots and associated localization and communication technologies. Among these technologies, ultra-low-frequency (30-300 Hz) electromagnetic waves have a significant advantage because of their strong penetration, which can penetrate metal pipe walls. Traditional low-frequency transmitting systems are limited by the size and power consumption of the antennas. In this work, a new type of mechanical antenna based on dual permanent magnets was designed to solve the above problems. An innovative amplitude modulation scheme that involves changing the magnetization angle of dual permanent magnets is proposed. The ultra-low-frequency electromagnetic wave emitted by the mechanical antenna inside the pipeline can be easily received by the antenna outside to localize and communicate with the robots inside. The experimental results showed that when two N38M-type Nd-Fe-B permanent magnets with a volume of 3.93 cm3 each were used, the magnetic flux density reached 2.35 nT at 10 m in the air and the amplitude modulation performance was satisfactory. Additionally, the electromagnetic wave was effectively received at 3 m from the 20# steel pipeline, which preliminarily verified the feasibility of using the dual-permanent-magnet mechanical antenna to achieve localization of and communication with pipeline robots.

Performance Evaluation of Standard and Modified OLSR Protocols for Uncoordinated UAV Ad-Hoc Networks in Search and Rescue Environments

Widespread usage of unmanned aerial vehicles (UAVs) in new and emerging applications needs dynamic and adaptive networking. The development of routing protocols for UAV ad hoc networks faces numerous issues because of the unique characteristics of UAVs, such as rapid mobility, frequent changes in network topology, and limited energy consumption. The Optimized Link State Routing (OLSR) protocol seems to be a promising solution as it offers improved delay performance. It is expected that OLSR will satisfy the strict demands of real-time UAV applications such as “search and rescue” (SAR) missions as it involves the most recent update of routing information. The classical OLSR routing protocol and its enhanced versions, D-OLSR, ML-OLSR, and P-OLSR, use different techniques to make an appropriate decision for routing packets. These routing techniques consider the quality of a wireless link, type of antenna, load, and mobility-aware mechanism to select the best UAV to send the message to the destination. This study evaluates and examines the performance of the original and modified OLSR routing protocols in UAV ad hoc networks for three SAR scenarios: (1) increasing mobility, (2) increasing scalability, and (3) increasing the allowed space of UAVs. It analyzes and validates the performance of the four OLSR-based routing protocols. It determines the best OSLR routing protocol by taking into account the packet delivery ratio, latency, energy consumption, and throughput. The four routing protocols and the SAR scenarios were simulated using NS-3.32. Based on the simulation results, ML-OLSR outperforms OLSR, D-OLSR, and P-OLSR in the considered measures.

Microstrip patch antennas for various applications: a review

<span lang="EN-US">This paper aims to review microstrip antennas for various applications. The design of microstrip patch antennas is a new research field developed for use in 5th generation communication applications. An antenna is a collection of multiple devices connected together that function as a single antenna to send or receive radio waves. Antennas can be of different shapes and sizes. The microstrip patch is an antenna pattern that is light in weight, low profile, and focuses on producing results. In the future, microstrip patch antennas may be used for some 6G communication systems applications. In addition, 6G communication applications can be created on other devices, including biomedical, autonomous vehicles, vehicle-to-vehicle (V2V) communication, internet of things (IoT), machine learning, Artificial Neural Network Algorithms, radar, and wireless communication. In the past, the multiple input, multiple output (MIMO) pattern was a standard geometry used in 4G wireless applications. This paper discusses the geometric structures of antennas, various analysis methods for antenna characteristics, antenna dimensions, and many different types of antennas. Also, it will discuss the previous papers' substrate materials, loss tangent, thickness, return loss, bandwidth, voltage-standing-wave-ratio (VSWR), gain, and directivity.</span>

Decoupling of Antenna Pairs Based on Equal Modal Conductance by Antenna-Shape Modification

In this article, a fundamental method based on mutual conductance elimination is proposed for the ultimate decoupling of closely spaced antenna pairs. First, the mutual coupling between radiators is characterized by lossy J/K inverters, and the analysis with circuit models shows that the traditional lumped loading method can only suppress the mutual susceptance. Particularly, the decoupling will not be ultimate unless the mutual conductance is further eliminated, which requires equal modal conductance of the odd and even modes of the antenna pair. After that, a method based on antenna-shape modification is proposed, and three types of antennas are designed with characteristic mode analysis (CMA). As for the single-band and wideband patch antenna pairs, by changing the patch shape into a parallelogram and adjusting the patch angle, the modal conductance of the odd and even modes are regulated to be equal, and the isolation is thus significantly improved when compared with the traditional ones to be loaded with lumped elements. As for the inverted-F antenna (IFA) pair, enhanced isolation is achieved by changing the bending configuration, coupling gap, and ground length of the antenna. Good agreement between simulated and measured results shows that all these antennas have achieved isolation over 20 dB.

Characteristic-Mode-Analysis-Aided Design of Filtering Patch Antennas

A characteristic-mode-analysis (CMA)-aided design method for filtering patch antennas is proposed in this article. The method mainly includes three parts: first, use the theory of characteristic mode (TCM) to analyze the filtering antenna without feed structure (i.e., the radiator) to find the resonant modes in the passband and predict the positions of the inherent radiation nulls, which are then utilized to obtain the suitable size of the radiator and filtering elements; second, use modal analysis to find the best feed position to excite the resonant modes and simultaneously generate the inherent radiation nulls; and third, optimize the filtering antenna to obtain the optimal overall performance. For demonstration, two different types of filtering patch antennas are investigated using the proposed method. It has been shown that the method can truly realize the independent analysis and design of the radiator structure and the feed with the help of characteristic modal analysis, making the design process of both filtering antennas clearer and more efficient. In addition, the proposed method can find out and fully utilize the inherent radiation nulls, including the modal nulls and the nonmodal nulls of the radiator itself.