Transmission Line Technique Research Articles

THz biosensing for early detection of influenza and coronaviruses using dielectric metamaterials

Abstract The world has faced a significant challenge since December 2019, when coronavirus (COVID-19) was found. Viruses of this type are causing pandemics all over the world right now. For this purpose, a biosensor is designed to operate based on metamaterial (MM) incorporated and can detect different coronaviruses. The proposed metamaterial absorber (MMA) includes two bands with perfect absorption characteristics and a narrow absorption bandwidth: 4.093 THz and 3.647 THz. The circuit model’s transmission line technique is another approach to verifying the absorber’s functionality. The proposed design consists of a square-shaped graphene ring (SGR) and a silicon-based square ring resonator (SSRR) to provide unique and narrow band absorption characteristics. Changing the graphene’s chemical potential suggests MMA tuneability and control capability. The suggested MMA can detect several coronaviruses because of its extremely narrow absorption spectrum behavior. It has unique features such as ultra-narrow absorption bandwidth, polarization insensitivity, and simplicity. The MMA is designed with a compact structure, good sensitivity (s), exceptional figure of Merit (FOM), and superior Quality factor (Q) values.

Line to Ground Fault Detector in 400 KV Transmission Line by Using Intelligent System

The ability to locate and identify problems in power transmission lines is the most crucial component of power system engineering since it ensures the stable and efficient operation of electrical grids. to minimize downtime, prevent cascading failures, and maintain the power system's stability. problem localization helps identify the precise location of the problem and speeds up the process of restoring the power supply while minimizing the impact on consumers. This paper presents a measurement-based automatic fault localization and detection (ANFIS) technique for transmission lines. High-speed processing of real-time error localization and detection is made possible by the design and implementation of ANFIS. It is suggested that ANFIS for digital distance protection systems be able to discover issues in addition to detecting them. When a transmission experiences a three-phase malfunction Thus, the suggested method can precisely pinpoint the impacted stages. ANFIS has been trained and tested using many kinds of field data. The field data are collected by simulating faults in the Simulink Matlab model depicting the transmission line at various sites between Misan – Kut station 400 Kv along 200 Km using computer software based on Matlab. Phase current and voltage measurements are utilized as ANFIS inputs and are available at the busses. Regarding the kind and detection of defects, The output will demonstrate fault and location identification with an extremely low error percentage through simulated processes; the results also demonstrate that the approach's selectivity and speed are quite dependable and provide adequate performance for applications involving transmission and distribution monitoring; and security. The study emphasizes the criticality of promptly and precisely locating faults in power transmission lines to preserve the stability and security of the power system.

Literature Review on Simulation and Measuring Techniques for Transmission Lines and Antennas

Literature Review on Simulation and Measuring Techniques for Transmission Lines and Antennas

Advancements in Fault Detection Techniques for Transmission Lines: A Literature Review

Advancements in Fault Detection Techniques for Transmission Lines: A Literature Review

Estimation of reflection loss of lossy dielectric powders using coaxial line based guided wave technique for conventional cement based microwave absorber applications

Coaxial transmission line technique to determine Plane Wave Reflection Loss of dielectric powders is proposed. The technique provides rapid determination of suitability of powders as conductive filler for Microwave Absorbers, specifically cement based Absorber. Ash by-product from steel industry including Argon Oxygen Decarburization (AOD), Acid Recovery Station (ARS) and Electric Arc Furnace (EAF) are considered over frequency range 1–12 GHz. Scattering parameters (S-matrix) of ash filled coaxial lines are measured. Short-Open technique is adopted. Formulation to compute reflection loss from measured S11 is presented. Teflon, with known reflection loss, is considered for validation. A 10 % error in computed results is observed in range 1–4 GHz, and 10–15 % in range 4–12 GHz. Broadband MAM characterization employing Free Space Methods involve enormous material requirement, frequency dependent prototype dimensions and anechoic chambers. The error percentage notwithstanding, the technique provides rapid estimates, enabling smart selection of conductive fillers, providing cost and time reduction.

A Fault Location Algorithm for Multi-Section Combined Transmission Lines Considering Unsynchronized Sampling

This paper introduces a fault location technique for multi-section combined transmission lines, utilizing unsynchronized fault record data. The approach determines the intersection points of the voltage magnitudes computed using the fault current and voltage records of each terminal and the constant line parameters of each section. Finally, the real fault location is identified based on the calculated inverse angle of equivalent impedance. To evaluate the performance of the proposed algorithm, a three-section combined transmission line is constructed using the PSCAD/EMTDC software version 5.0.0, and various fault scenarios are simulated and tested employing the proposed algorithm. The results indicate that the proposed algorithm is applicable to various types of faults in a multi-section combined transmission line; the estimations are accurate.

Routing Technique for Microwave Transmission Lines to Ensure UWB Interference Immunity

This article presents a novel routing technique for designing microwave transmission lines (TLs) that provide improved functionality. Unlike traditional practices, we propose locating two independent traces close to each other, resulting in strong electromagnetic coupling and potential unwanted crosstalk between traces. However, we show that the suggested routing schemes can significantly increase the ultra-wideband interference immunity of electrical circuits by using modal distortions and reflections, as demonstrated in our study of four prototypes of TLs in the form of serpentine and spiral designs with strong and weak coupling between pairs. To better predict and analyze the microwave behavior in such TLs, we used new simulation techniques based on the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N$</tex-math> </inline-formula> -norms study. Our investigation of these TLs in a transverse electromagnetic cell in the frequency range from 10 MHz to 5.3 GHz showed a low level of radiated emissions. The results indicate that the serpentine scheme with strong coupling between pairs provides the best protection of two independent TLs against ultra-wideband interferences. Moreover, the used electrodynamic approach is in full agreement with the experimental study, further validating the effectiveness of the proposed routing technique.

Silicone rubber‐nanoceramic composites for 5G antenna substrates

AbstractHere, the eligibility of silicone rubber‐nanoceramic composites as flexible substrates for sub‐6 GHz 5G antennas is investigated. Two different composites are prepared using the solution mixing method, namely mono and hybrid composites. The reflection and transmission coefficient (S‐parameters) of composites are measured using a rectangular waveguide‐based transmission line technique in conjunction with a Vector Network Analyzer (VNA) at C‐band frequencies (4–8 GHz). The Nicolson–Ross–Weir (NRW) algorithm is adopted to extract the complex permittivity and loss tangent of the material under test. Due to the synergetic effect, the silicone rubber hybrid composite (0.12BiVO4+0.12LaNbO4) exhibits the advantage of a lowered loss tangent while retaining a good dielectric constant at 5.78 GHz. A rectangular microstrip patch antenna is designed and simulated with CST software using 0.12BVO/0.12LNO/0.76SR composite as a substrate. Moreover, based on the simulation, the antenna with the proposed substrate has acceptable performance at 5.78 GHz with the return loss, directivity, and gain of −25.05 dB, 5.46 dBi and 2.74 dBi, respectively. As a result, the composite material's ability to act as a suitable substrate for a 5 GHz Wi‐Fi antenna is confirmed.

Time derivatives via interconnected waveguides

Electromagnetic wave-based analogue computing has become an interesting computing paradigm demonstrating the potential for high-throughput, low power, and parallel operations. In this work, we propose a technique for the calculation of derivatives of temporal signals by exploiting transmission line techniques. We consider multiple interconnected waveguides (with some of them being closed-ended stubs) forming junctions. The transmission coefficient of the proposed structure is then tailored by controlling the length and number of stubs at the junction, such that the differentiation operation is applied directly onto the envelope of an incident signal sinusoidally modulated in the time domain. The physics behind the proposed structure is explained in detail and a full theoretical description of this operation is presented, demonstrating how this technique can be used to calculate higher order or even fractional temporal derivatives. We envision that these results may enable the development of further time domain wave-based analogue processors by exploiting waveguide junctions, opening new opportunities for wave-based single operators and systems.

Fault location in power grids using substation voltage magnitude differences: A comprehensive technique for transmission lines, distribution networks, and AC/DC microgrids

Power grids are highly susceptible to various types of faults and their associated consequences. In recent years, numerous fault location methods have been proposed for different types of power networks. Generally, these methods determine the location of a fault by measuring current and voltage data on one or both sides of the line. However, the use of current data can result in calculation errors due to the saturation state of the current transformer and the bidirectional fault current. Moreover, the use of measuring devices in different nodes can lead to increased costs and the need for advanced telecommunication systems and data synchronization. In this paper, we propose a comprehensive technique for fault location in power networks that incorporates the presence of D-STATCOM and considers the effect of line capacitors. Our method estimates the distance and faulty branch by measuring the difference in fault voltage magnitude at the substation and comparing it with simulated faults in other branches. Unlike other methods that rely on current data, our proposed technique is independent of current data, resulting in higher accuracy and faster fault detection. Furthermore, our method offers significant cost savings compared to other fault location methods. To evaluate the performance of our technique, we conducted simulations on a 32-node power network in MATLAB/SIMULINK and an 8-node network in a power system simulator. We tested the sensitivity of our method to various fault locations, resistances, and DG penetration levels. The results of our simulations demonstrate the high accuracy and speed of our proposed technique, making it a promising alternative to other fault location methods in the field.

Transmission Line Protection Using Decaying DC Information in Fault Current

Today use of fast and reliable transmission line protection is of importance. This paper presents two protection techniques for transmission lines using information obtained from the decaying DC component of fault current and the pre-fault voltage signal. The fault direction is obtained using the polarities of pre-fault voltage and decaying DC of fault current. Internal faults in the transmission lines are detected with exchange of information on the decaying DC currents at both ends. The protection decisions are derived within a quarter cycle with a signal sampling rate of 4 kHz. Upon testing on a 400 kV simulated transmission system for different fault types, resistances, inception angles, and field data from a 400 kV line, the proposed techniques are found to be accurate.

Space charge dynamics of epoxy/micro-Al2O3 composites under multi-physical fields

The direct current gas insulated transmission line (DC GIL) technique has emerged as a promising solution to achieve carbon neutrality and enable efficient long-distance transmission of renewable energy. However, the stable and long-term operation of DC GIL insulators poses a significant challenge that requires insulating materials capable of overcoming charge accumulation issues against multi-fields, including electric, temperature, and force. Here, we investigate the space charge dynamics and electrical conductivity of epoxy (EP) resin and EP/micro-Al2O3 composites under various stimuli of electrical, thermal, and mechanical stresses, using two modified pulsed electro-acoustic and electrical conductivity measurement systems with mechanical pressure control. It is found that stronger electric fields and higher temperature conditions have a more significant impact on space charge accumulation, while higher mechanical stress results in more shallow traps in EP composites. Furthermore, the bipolar carrier transport modeling and numerical calculations are performed to rationalize the experimental observations and reveal the mechanistic impacts of multi-physical fields on the space charge behavior of EP composites for DC GIL insulator use.

Yttrium-substituted Co0.5Ni0.5YxFe2-xO4 ferrites as microwave absorbers by investigating structural, magnetic, dielectric, and absorption characteristics

The effect of Yttrium Substitution on Co0.5Ni0.5YxFe2- xO4 (0.0 ≤ x ≤ 1.0) Ferrites as Microwave Absorbers was investigated to include structural, magnetic, dielectric and X-band absorption properties. The main objective of this work is to enhance microwave absorption properties of materials with interesting dielectric/magnetic behaviors by doping rare earth element of Yttrium based on transition metals. The hydrothermal method was used to create Yttrium (Y) substituted nanoparticles, and the effects of Y-ion substitution on the characteristics, structural, magnetic features were examined by XRD, FT-IR, SEM-EDS, TEM-SAED, and VSM, respectively. Electromagnetic properties were obtained from microwave scattering parameters measured via a metal-backed transmission line and Nicholson-Ross Weir techniques using a vector network analyzer (VNA) in conjunction with an X-band waveguide set. Return loss (RL) values of the samples were obtained from the electromagnetic constitutive parameters (permittivity and permeability). According to the XRD measurements, hexagonal crystal structure of ferrite and YFeO3 as secondary phase nanocrystal sizes are between 11 and 67 nm. Refined structural parameters using Rietveld analysis are carried out using the TOPAS refinement program. A good match was observed between the diffraction patterns obtained and calculated by Rietveld analysis. Moreover, the morphological analyses indicate that the relatively small spherical structures of Ni-Co ferrites particles can be seen to change from spherical to hexagonal-shaped with increasing yttrium concentration. The results of the FT-IR study show that the spinel structure has formed as predicted because the expected range of absorption bands is present. According to magnetic measurements, the coercivity (Hc) results show a modest increase in porosity as the Y-content rises. The results revealed that the minimum RL value and bandwidth vary significantly with the amount of Yttrium in the mixture, indicating that the obtained structures will be useful for broadband microwave applications.

Two Terminal Instantaneous Power-Based Fault Classification and Location Techniques for Transmission Lines

Transmission lines are an important part of the power system, as they are the carriers of power from one end to another. In the event of a fault, the power transferring process is disturbed and can even damage the equipment, which is attached to the generation end as well as the user end. Most of the power systems are connected to the transmission lines, so it is very important to make the transmission lines secure. For protection purposes, relays are used, but relays only trip in the event of a fault and do not tell us about the location of the fault. The power system requires a speedy protection system. For a speedy protection system, quick and fast fault analysis and classification are required. An effective approach for the analysis of the transmission line with three sources is proposed. This method is quite effective and accurate for locating the fault and classifying its types. This technique needs power measurement from both ends simultaneously for fault diagnosis. Instantaneous power and sign power values are used for fault detection and classification. A voltage profile is used to identify the fault location. For three-phase transmission lines, voltage profiles are built up at different segment points to locate the fault. The IEEE-9 bus system is simulated for this technique. MATLAB is employed for simulation purposes. The test system is simulated with different types of faults at different locations. Relay operation has not affected the accuracy of the system. This technique has an accuracy of more than 97%. This method is quite effective for the analysis of power transmission lines. It can discriminate the fault type, identify the faulty phase of the line, and locate the point of the fault. Faults are located with errors not more than 0.45%. Moreover, the time difference between the actual fault and the calculated fault obtained from the estimated location is not more than 0.004 s. Simulations are claimed to be executed in less computational time, ensuring effective and rapid protection against faults.

The electromagnetic wave absorption properties of woven glass fiber composites filled with Sb2O3 and SnO2 nanoparticles doped mica pigments

AbstractIn this study, the electromagnetic wave absorption properties of woven glass fiber reinforced epoxy composites with Sb2O3 and SnO2 nanoparticles doped mica pigments were investigated. Herein, we synthesized SnO2/mica, Sb2O3/mica, and Sb2O3:SnO2/mica pigments using the sol–gel method. Subsequently, mica pigments filled glass fiber/epoxy composite panels were fabricated with a vacuum assisted resin mold. The phase, crystal, and morphological examinations of particles confirm the deposition of SnO2 and Sb2O3 nanoparticles on the mica surfaces. The electromagnetic wave absorption properties of samples were measured using the S parameters and obtained dielectric data. Sb2O3:SnO2/mica particles display higher complex permittivity and dielectric loss values due to the strong interfacial polarization between conductive nano metal‐oxide shells and mica surfaces. According to the calculated reflection loss values, Sb2O3:SnO2/mica particles exhibit superior electromagnetic wave absorption performance with a minimum reflection loss of −25.62 dB for 2.4 mm thicknesses with effective bandwidth between 9.3 and 12.4 GHz. The S parameters of the prepared structural composites with the size of 30 cm × 30 cm × 3 mm was determined by the free‐space technique using the transmission line technique. According to the S12 parameters, filled glass fiber/epoxy composite containing 25 wt% Sb2O3:SnO2/mica show a minimum reflection loss of −20.426 dB at 8.2 GHz with effective bandwidth between 8.2 and 9.67 GHz. These results indicate that Sb2O3:SnO2/mica‐filled fiber/epoxy composite is an excellent candidate for the practical application of electromagnetic wave absorbers.

Time-Domain Techniques for Line Protection Using Three-Dimensional Cartesian Coordinates

Today high speed protection of power system elements is necessary and realizable. This paper introduces time-domain protection techniques for transmission lines using voltage and current signals in Cartesian coordinates. Three techniques are proposed using this approach for line protection. Direction of fault is obtained using change in angle between Cartesian planes of voltage and current. In the second application on unit protection scheme, internal and external faults in transmission lines are discriminated using dot product of the normals to both end current planes. Fault type identification is obtained using the angle between incremental changes in currents in Cartesian coordinates. The output of each protection function using the new concept is derived in a quarter-cycle. The performance of each of the proposed techniques is tested for load variation, high resistance fault, different fault types, power swing, fault inception angles and signal with noise. Further, the proposed techniques are evaluated using field data from a 400 kV double circuit line.

Influence of woven fabric construction parameters on electromagnetic shielding effectiveness: Part I – weave influence

The development of textiles with the ability to shield an electromagnetic field is still of great interest, and the influences of the construction parameters of woven fabric (weave, input fibrous material composition, three-dimensional (3D) construction) on the resulting electromagnetic shielding efficiency have still not been sufficiently investigated. The main goal of this study is therefore to analyze the weaves of special electrically conductive woven fabrics and evaluate their impact on electromagnetic shielding effectiveness (SE) using statistical methods. Here, the interlacing structure cells of woven fabric are newly used to describe the weave. The results confirmed that the proposed theory of the interlacing of woven fabric is satisfactory for evaluating and, especially, for prediction of the SE of electromagnetic shielding woven fabrics. For this study, the input yarn (made from a mixture of traditional and extremely thin discrete stainless steel fibers) is used for the production of 21 types of dobby woven fabrics with different weaves and its SE was analyzed using the coaxial transmission-line technique. This contribution can be used as theoretical guidance for the construction, design, and production of special woven fabrics (dobby and jacquard pattern) with controlled SE.

Probes in transmission with material variable thicknesses to extract the material complex relative permittivity in 1.7–3 GHz

A significant investigation on the use of two probes in the transmission is presented in this paper. As a transmission-line technique, those two probes separated with a variable thickness of the sample under test to determine the material dielectric constant from the transmission phase constant constitute the basis of the proposed technique novelty. This new approach replaces each configuration's measured electric length to widen the covered frequency range through the new phase definition or model. Using the material thickness and the probe inner conductor dimension through a mathematic function model to get to the material's complex relative permittivity (dielectric constant and loss tangent) is the best way to include discontinuity impacts in this concept to reach the goal. The approach has been tested on the standard materials: FR4, Alumina 99.6%, and Roger RO4003C with thicknesses between 0.79 mm and 2.0 mm. In addition, the Anritsu MS4642B 20 GHz Vector Network Analyzer (VNA) has been used to scan the frequency range 1.7–3 GHz and validates the approach. Metal in contact with both probes is placed under the controlled space representing the material thickness to improve the loss tangent extraction. One test cell is fixed, while the second is movable.

Material Relative Permittivity Determination From the Inhomogeneous Transmission-Line Secondary Parameters

After further transmission line technique investigation, we propose a new approach to material characterization based on the combination of the propagation constant and the characteristic impedance of the transmission-line. Three main elements constitute the approach novelty’s root: the determination of the propagation constant without using the eigenvalue principle, the improved mathematical expression of the characteristic impedance, and the automatically corrected coefficient. The two-line technique is based on three required measures, where the most extended fixture is partially filled with the specimen to be tested. As a result, the discontinuities caused by the geometric change of access interfaces and the waveguide dimensions have been solved. The characteristic impedance is determined straight and amended by a third polynomial function degree. The polynomial function and the amended correction coefficient determination are the facilitation parameters of the new approach technique. This new method allows the extraction of the material’s complex relative permittivity. The procedure has been validated with the Rogers RO4003C, Alumina 99.6%, and Vinifera (based on the dielectric materials available in our laboratory) through the microstrip fixture in the scanned frequency (0.08 – 8) GHz by extracting its electric intrinsic parameters. The dielectric constants range from 1.1–10.4, where the thicknesses are 1.54 mm, 2.067 mm, and 1.078 mm have been used. Two identical microstrip test cells with the same geometric dimensions but various lengths have been manufactured. That promotes the feasibility of two measures simultaneously.

A Nonlinear Transmission Line Technique for Generating Efficient and Low-Ringing Picosecond Pulses for Ultrabroadband and Ultrafast Systems

This paper presents a nonlinear transmission line (NLTL)-based scheme to develop an efficient and low-ringing picosecond pulse generator for ultrabroadband and ultrafast system applications. The proposed NLTL scheme stems from a unique combination of single varactor diode and stacked varactor diode per NLTL cell, which is designed to exploit a significant effect of non-linearity in connection with the varactor diode. This technique generates a higher compression factor in both rise and fall time of NLTL circuits in comparison to single varactor diodes per NLTL section. This scheme is validated to work well in a triple-stacked NLTL topology by maximizing the compression factor. Two pulse generators are then developed based on the proposed concept, where a mixed SRD topology is used for gaussian pulse generation and integrated with a triple-stacked NLTL. This achieves shorter pulse durations and a higher compression capability. The use of NLTLs with triple-stacked varactor diodes in a cell is also explored theoretically and is shown to maximize the compression capability by effectively increasing the punch through, turn-on, and break down voltages. Theoretical development and simulation of two triple-stacked NLTLs based on the rise and fall time-compression are provided, and final experimental prototypes for pulse generators are fabricated and measured. It is found from measurements that the full-width half maximum (FWHM) of the rise time-compression-based pulse generator is almost 15.78ps with a ringing level of -11.29dB, while the FWHM of the fall time-compression-based pulse generator is almost 17ps with a ringing level of -8.43dB. Finally, these pulse generators are compared with the current states of the art in terms of the implemented scheme, pulse duration, FWHM, pulse shapes, and detailed ringing level. The reconfigurable capability of the pulse generators is also briefly explored, and it is shown that the proposed pulse generators can easily be reconfigured between gaussian and monocycle pulse shapes. The power spectrum of the proposed pulse generators is also presented. It is found that they are well suitable for ultra-broadband and ultrafast systems, such as Impulse Radar Ultrawideband (IR-UWB) applications, due to higher pulse compression capability, ease of integration, flexible pulse tunability, and modification to higher order gaussian waveforms.