Transmission Line Configuration Research Articles

Vulnerability to Parameter Spread in Josephson Traveling-Wave Parametric Amplifiers

We analyze the effect of circuit parameter variation on the performance of Josephson traveling-wave parametric amplifiers (JTWPAs). Specifically, the JTWPA concept we investigate is using flux-biased nonhysteretic rf-SQUIDs in a transmission line configuration, which harnesses the three-wave mixing (3WM) regime. Dispersion engineering enables phase-matching to achieve power gain of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\sim$</tex-math></inline-formula> 20 dB, while suppressing the generation of unwanted mixing processes. Two dispersion engineering concepts using a 3WM-JTWPA circuit model, i.e., resonant phase-matching (RPM) and periodic capacitance modulation (PCM), are discussed, with results potentially also applicable to four-wave-mixing (4WM) JTWPAs. We propose suitable circuit parameter sets and evaluate amplifier performance with and without circuit parameter variance using transient circuit simulations. This approach inherently takes into account microwave reflections, unwanted mixing products, imperfect phase-matching, pump depletion, etc. In the case of RPM the resonance frequency spread is critical, while PCM is much less sensitive to parameter spread. We discuss degrees of freedom to make the JTWPA circuits more tolerant to parameter spread. Finally, our analysis shows that the flux-bias point where rf-SQUIDs exhibit Kerr-free nonlinearity is close to the sweet spot regarding critical current spread.

A Millimeter-Wave GaN MMIC Front End Module with 5G NR Performance Verification

This paper proposes a millimeter-wave (mmWave) 5G front end module (FEM) based on multiple gallium nitride (GaN) monolithic microwave integrated circuits (MMICs) with 5G new radio (NR) performance verification. The proposed structure is configured by a wide band GaN single-pole double-throw (SPDT) switch MMIC, a GaN low-noise amplifier (LNA) MMIC, and a GaN power amplifier (PA) MMIC with the target operation band from 26.5 GHz to 29.5 GHz. The LNA and PA MMICs are designed with 150 nm GaN/SiC technology, and the SPDT MMIC is designed with 100 nm GaN/Si. The LNA MMIC shows the measured noise figure less than or equal to 2.52 dB within the operation band. The PA MMIC is based on a two-stage configuration and shows about 35 dBm measured saturated power with power-added efficiency better than 34% within the operation band. Also, the SPDT MMIC is based on an artificial transmission line configuration for wideband performance and shows that the measured insertion loss is less than 1.6 dB, and the measured isolation is higher than 25 dB within the operation band. Furthermore, all MMICs are integrated within a single carrier as an FEM and successfully verified by 5G NR test signals.

Fault Identification on Electrical Transmission Lines Using Artificial Neural Networks

Transmission lines are built to span over long distances, to which they are frequently exposed to many different situations that can cause abnormal conditions known as electrical faults. Electrical faults, when isolated, can cripple the transmission system as power flows are directed around these faults therefore leading to other numerous potential issues such as thermal and voltage violations, customer interruptions, or cascading events. Accurate fault classification and location is essential in reducing outage times and enhancing system reliability. Diverse methods exist and have different strengths and weaknesses. This paper aims to investigate the use of an intelligent technique based on artificial neural networks. The neural networks will attempt to determine the fault classification and precise fault location. Different fault cases are analyzed on multiple transmission line configurations using various phasor measurement arrangements from the two substations connecting the transmission line. The results can provide guidance on choosing the most efficient neural network structure and input measurements for transmission line fault classification and location.

Novel Method for Magnetic Flux Density Estimation in the Vicinity of Multi-Circuit Overhead Transmission Lines

In this paper, a novel method for the magnetic flux density estimation in the vicinity of multi-circuit overhead transmission lines is proposed. The proposed method is based on a fully connected feed-forward artificial neural network model that is trained to estimate the magnetic flux density vector components for a range of single-circuit overhead transmission lines. The proposed algorithm is able to simplify estimation process in instances when there are two or more geometrically identical circuits present in the multi-circuit overhead transmission line. In such instances, artificial neural network model is employed to estimate the magnetic flux density distribution over a considered lateral profile for only one of such circuits. The magnetic flux density estimates of the other geometrically identical circuits are derived from these results. The proposed methodology defines the resultant magnetic flux density for the multi-circuit overhead transmission line in terms of the contributions made by individual circuits. The application of the proposed magnetic flux density estimation method is demonstrated on several multi-circuit configurations of overhead transmission lines. The performance of the proposed method is compared with the Biot-Savart law based method calculation results as well as with field measurement results.

W-Band MMIC Chip Assembly Using Laser-Enhanced Direct Print Additive Manufacturing

In this article, the first W-band laser-enhanced direct print additive manufacturing (LE-DPAM) monolithic microwave integrated circuit (MMIC) chip-carrier assembly is demonstrated. Acrylonitrile butadiene styrene (ABS) is 3-D printed using fused deposition modeling to form substrate layers, and DuPont CB028 conductive paste is microdispensed to form transmission lines and on-chip interconnects. These processes are combined with picosecond-pulsed laser micromachining using two wavelengths in the infrared (IR) (1064 nm) and ultraviolet (UV) (355 nm) regions to create features as small as 5 μm for printed layers with a high 6:1 aspect ratio and to improve the effective conductivity of the printed traces. The laser machining process is also adopted to fabricate vertical interconnections (vias) over multilayer substrates while also suppressing higher order modes. Four different dc-to-110-GHz transmission-line configurations have been investigated, including a coplanar waveguide (CPW), a grounded CPW (GCPW), a novel multilayer CPW-microstrip transition, and a GCPW-microstrip transition with attenuation 10 dB. This process is extended to embed a W-band MMIC low-noise amplifier (LNA) die inside a laser-machined cavity with a carrier-chip gap less than 5 μm. Also, RF/dc interconnects were microdispensed to connect the transmission lines on the substrate and MMIC die. Chip-to-board transition loss as low as 0.03 dB per interconnect with return loss >7.5 dB was achieved with performance that is comparable to that of the probed MMIC die. The MMIC chip-carrier assembly provides a low-cost, versatile yet simple on-demand laser-enhanced additive manufacturing process to package a wideband MMIC die using a single automated LE-DPAM platform.

A quad-band miniaturised compact Π-shaped CSRR-based metamaterial-inspired DG resonator antenna

ABSTRACT Proposed in this paper is a new configuration for a quad-band antenna based on using a metamaterial-inspired defected ground structure. The presented structure is introduced as a new modified metamaterial Complementary Split Ring Resonator (CSRR) with a compact electrical size. The new modified CSRR has been employed in Composite Right/Left-Handed (CRLH) transmission line configuration for ultra-size reduction. Validation for the particle small size is introduced and the detailed analysis for the NRI characteristics has been discussed by extracting the cell constitutive parameters. Hence, a multi-band antenna is designed based on using only one cell of the proposed NRI-TL. Subsequently, a small multi-band antenna is presented for different multi-band functionalities and different radiation properties. The antenna displays quad-resonances at 1.78 GHz, with the typical omnidirectional radiation pattern, 3.28 GHz, 4 GHz, and 4.3 GHz, with the directive broadside radiation properties. The proposed antenna footprint is 10 × 10 cm2, which exhibits a size reduction of up to 80% in comparison with a rectangular patch antenna operating at the lowest frequency band.

Wave Propagation on High Voltage Power Lines.(Dept.E)

Travelling waves in power systems is of importance in solving problems relating to power-line carrier communication, protection of very long lines, energiestion of unloaded lines and calculation of recovery voltages on cir-cuit breakers under fault conditions. This paper presents comprehensive analyses for wave propagation on single-phase and on three-phase overhead power transmission lines. Using modal quantities, the wave equation are solved. Natural modes are illustrated to clarify the propagation of carrier signals on single circuit lines as well as on double circuit lines. Different transmission line configurations are considered. The effect of power line transposition on carrier modes is also included.

Tapered transmission lines for terahertz systems.

Complex terahertz (THz) System-on-Chip (TSoC) circuits require ultra-wideband low-loss low-dispersion interconnections between building-block components of various dimensions and characteristics. Tapered transmission lines, which enable the gradual transformation of both physical dimensions and characteristic impedance, are a convenient basis for these interconnections. In this paper, we quantify both experimentally and through simulation, the efficacy of transmission-line tapers connecting two different coplanar-strip transmission-line configurations, for frequencies up to 2.0 THz and with 25 GHz spectral resolution. We demonstrate tapers that enable transitioning from a small device-constrained transmission-line dimension (10 μm line width) to a lower-loss (20-40 μm line width) dimension, as a method to reduce the overall attenuation, and outline design constraints for tapered sections that have minimal detrimental impact on THz pulse propagation.

Design method of Dual-Band Wilkinson power divider with designable length and high design freedom

A new theory of designing dual-band power divider (PD) based on Wilkinson structure is presented in this paper. Because of the utilization of coupled lines, the proposed PD is with a high design freedom that many transmission line (TL) combinations can be used for a fixed frequency ratio k (ƒ2/ƒ1). Meanwhile, since the lengths of the conventional coupled lines used are extremely long, the slow-wave structure is introduced, which configuration results in a property of designable length and compact size because of the improved space efficiency. After analysing the even- and odd-mode circuits, precise design formulas are derived and further verified for the frequency ratio from 1.5 to 6.0 using NI AWR simulator under the consideration of the largest realizable TL impedance as 128 Ω. For verification, two PDs with the same centre frequency of 1.0 GHz and 4.0 GHz but different TL configurations are designed based on the proposed design theory. According to the experimental results, both fabricated PDs have good performances as expected, such as low in-band insertion loss (S21), wide isolation, and relatively better out-of-band rejection than majority of previous studies that the maximum S21 between the two passbands is larger than 6 dB, while previous studies are around 4 dB.

Aging Characteristics and Influencing Factors of the Sheds of Composite Insulators in Karst Regions of China

In recent years, more and more high-voltage overhead transmission lines were built passing through the karst regions in southwestern China. This type of special landform seems to have an adverse effect on the aging of the sheds of the line suspension composite insulators, which may lead to unexpected flashover and line tripping. In order to find out the particularity of the aging characteristics of insulators operating in the karst regions, samples in operation were selected from both the karst regions and the flatlands. Hydrophobicity, amount of surface contamination, and contaminant composition of the sheds were studied, then a comparison of performance between the two was made, and the possible influencing factors that cause such differences were discussed. The results show that the overall aging of the sheds of the composite insulators operating at the karst regions is more aggravated, which is caused by the combined influence of factors including the special topography, climate, and pollution in the area. The strong wind crossing the col will bring about the mutual scraping on the edges and stress concentration at the root of the sheds, leaving scratches and root cracks; the infiltration from these rupture of acid liquid, if any, will accelerate the aging and corroding of the internal silicone rubber material; moreover, the carbonates enriched on the surface of the sheds will gradually transform into more corrosive sulfates in an acidic environment, leading to further deterioration and chalking of the sheds of the insulators. The research work in this paper can provide guidance for the current operation and maintenance of composite insulators in the karst areas, as well as having important reference values for the layout design and insulation configuration of transmission lines to be built across karst landforms in the future.

Electric and Magnetic Field Estimation Under Overhead Transmission Lines Using Artificial Neural Networks

In this paper, a novel method for electric field intensity and magnetic flux density estimation in the vicinity of the high voltage overhead transmission lines is proposed. The proposed method is based on two fully connected feed-forward neural networks to independently estimate electric field intensity and magnetic flux density. The artificial neural networks are trained using the scaled conjugate gradient algorithm. Training datasets corresponds to different overhead transmission line configurations that are generated using an algorithm that is especially developed for this purpose. The target values for the electric field intensity and magnetic flux density datasets are calculated using the charge simulation method and Biot-Savart law based method, respectively. This data is generated for fixed applied voltage and current intensity values. In instances when the applied voltage and current intensity values differ from those used in the artificial neural network training, the electric field intensity and magnetic flux density results are appropriately scaled. In order to verify the validity of the proposed method, a comparative analysis of the proposed method with the charge simulation method for electric field intensity calculation and Biot-Savart law-based method for magnetic flux density calculation is presented. Furthermore, the results of the proposed method are compared to measurement results obtained in the vicinity of two 400 kV transmission lines. The performance analysis results showed that proposed method can produce accurate electric field intensity and magnetic flux density estimation results for different overhead transmission line configurations.

Methodology to calculate the density of the magnetic field generated in overhead transmission lines in HVDC applying a two-dimensional analysis of parallel poles above ground level

The growth in the demand for electricity has led to the development and application of technologies that make its means of transport more efficient. Thus, one of these options is the implementation of transmission lines in HVDC. One of important design parameters of these lines is to know their magnetic field distribution, when it is required to calculate it, there is no methodology that can be applied to HVDC transmission lines. The following article presents a methodology that allows obtaining the density of the magnetic field on the corridor of an overhead transmission line. A case study of a 500 kV bipolar line in HVDC is presented, the results obtained are compared using the commercial software Field and corona Effects (FACE), the results obtained are consistent with those obtained from the presented methodology. An analysis of the impact of the transmission line configuration on the magnetic field density is developed, defining the most efficient configuration.

ELECTROMAGNETIC INTERFERENCE (EMI) PRODUCED BY HIGH VOLTAGE TRANSMISSION LINES

Electromagnetic interference in high voltage transmission lines has been an interest topic due to its effect on human health, plants, electrical and telecommunication equipment. Extremely high voltages (EHV) in transmission lines are reasons of electrostatic effects, while short circuit currents and line loading currents are responsible for electromagnetic effects. The aim of this research is to analyze electromagnetic fields in high voltage transmission lines in theoretical study and calculating its level in overhead T. L and therefore estimated the EMI produced, by employing a mathematical model of 230 KV tower double circuit configurations of high voltage transmission lines. The calculation is based on computer aided analysis (CAA) by using fields and corona effects software (FACE). It's found that the overhead power lines of general frequency (50 Hz) generates a highly intense magnetic field, the electromagnetic fields depends on the distance from sources and the type of line configuration. They decrease as the distance increase from the tower and conductors and increase with a high current. The strength of an electric field is proportional to the voltage of the line and the magnetic field strength is proportional to the current in the high voltage transmission lines. Distribution line with a high current load may produce a magnetic field that is as high as those produced by some high voltage transmission lines. Some techniques of reduction of the effects of electromagnetic interference have suggested such as rearrangement conductors of transmission line, and distance from phase conductor and grounding system. The study recommended to keep safety distance operation in high voltage transmission lines with the necessity for engineer to take into account the effect of electromagnetic interference in the design stage of high voltage transmission power system, and to avoid any addition cost may be occur due to neglected effects of electromagnetic interference that produces by high voltage transmission lines

Multi-Stage Transmission Network Planning Considering Transmission Congestion in the Power Market

The uncertainty of generation and load increases in the transmission network in the power market. Considering the transmission congestion risk caused by various uncertainties of the transmission network, the optimal operation strategies of the transmission network under various operational scenarios are decided, aiming for the maximum of social benefit for the evaluation of the degree of scenario congestion. Then, a screening method for major congestion scenario is proposed based on the shadow price theory. With the goal of maximizing the difference between the social benefits and the investment and maintenance costs of transmission lines under major congestion scenarios, a multi-stage transmission network planning model based on major congestion scenarios is proposed to determine the configuration of transmission lines in each planning stage. In this paper, the multi-stage transmission network planning is a mixed integer linear programming problem. The DC power flow model and the commercial optimization software CPLEX are applied to solve the problem to obtain the planning scheme. The improved six-node Garver power system and the simplified 25-node power system of Zhejiang Province, China are used to verify the effectiveness of the proposed multi-stage planning model.

A Simplified Method for Quick Calculation of Corona I–V Characteristics of Unipolar Transmission-Line Configurations

This article is concerned with the calculation of the corona current-voltage characteristics of a unipolar high-voltage direct current (HVDC) transmission line with a single conductor stretched above the ground plane. In light of justified assumptions, the corona charge density around the conductor surface is obtained using an iterative procedure. This makes it possible to calculate the corona current for a given applied voltage. It is interesting to note that the per-unit charge density around the conductor surface with reference to its value at the gap axis has the same distribution irrespective of the conductor radius and height above the ground plane as well as of the applied voltage. Along this axis, Deutsch's assumption is waived and the charge density is calculated as being dependent on the conductor radius, conductor height, onset voltage, and applied voltage. A curve-fitting polynomial is made for the per-unit distribution of charge density around the conductor surface. Determination of the surface charge density at the gap axis and the polynomial describing the per-unit charge density distribution represent the basis of a proposed simplified method for quick calculation of the I-V characteristics, irrespective of the conductor radius and height above the ground plane. The corona current-voltage characteristics, as calculated by the proposed simplified approach, are compared with those calculated before and with those measured in different laboratories. The computation time is drastically reduced when using the proposed simplified method.

A Band Pass Coupled Line Filter with DGS for Ultra-Wide Band Application

Abstract Systems with ultra-band width make use in wireless scenario which enables information transmission over long range of frequency of small distances with a minimum power and high information rates. An ultra-wide band filter is an important requirement for high-quality signal transmission and reception. Designing a compact UWB filter insertion loss much lower is a very difficult task. A structure with ground defected is defined to be etched periodically or non-periodically, cascaded configuration of a planar transmission line whose ground is defected disturbs the current distributed in the ground. A microstrip ultra-wideband filter is introduced in this paper. The filter includes interdigital feed lines on the upper face of substrate and rectangular-shaped structure defected ground at the bottom. The filter is 26.5 x 7.546 x 1.6 mm3 of dimension. The filter provides excellent passband (from 2.4-14.3 GHz) with a reduced return loss of -21.24 dB and insertion loss of -0.7dB at 6.9 GHz. Simulations are carried using ANSYS HFSS Electromagnetic Solver version 16.2.

Quantitative effect of dust on photovoltaic supply of transmission line monitoring device and configuration correction

Aiming at the problems that the photovoltaic power supplies of transmission lines monitoring devices are liable to be discontinuous and damaged, it is found that the power loss caused by surface dust deposition cannot be ignored. Improper configuration via empirical formula may result in power shortage and long-term undercharging of the battery, finally shorten the equipment's life. What is more, artificial and field experiments were carried out to find the qualitative impact, and the attenuation coefficient related to dust deposition may ensure a more appropriate configuration. This research provides a reference for power supply design and helps to save the replacement.

Power System Design for a Large, Dynamic Natural Gas Field: Improving the Field Production Profile

In this article, we detail the upgrading of a large natural GAS field to improve the field production profile of the nonassociated gas recovery rate of the existing wells. Several gas compression plants (GCPs) with nearly 20 large, high-voltage (HV) motors will be optimally located based on thermohydraulic modeling results. This requires a power system network that provides a reliable and stable power supply to critical operations, delivering over 3 billion standard cubic feet per day of compressed gas. These GCPs are located in remote areas with severe Middle East weather conditions. The technical challenges for designing and ensuring power delivery to these locations without sacrificing quality, reliability, and safety are reviewed. Analyzing the design, planning, installation options, construction techniques, safety requirements, and logistical methods used in the design are discussed. It also addresses the interface with the utility, HV transmission line configuration, selection of substation equipment, and motorstarting methods to distribute power from the bulk supply point (BSP) to the GCPs.

Selectivity-Enhancement Technique for Stepped-Impedance-Resonator Dual-Passband Filters

A class of stepped-impedance resonator (SIR) dual-band bandpass filter (BPF) with selectivity-enhancement cells is reported. These dual-band filtering cells, which are composed of two open-ended transmission-line segments interconnected at the input, are added at one node of the input and output coupled-line stages. Thus, with regard to the SIR dual-band BPF without cells, they increase the order of each passband by two and simultaneously generate transmission zeros (TZs) at both sides of the two transmission bands. The operating principles of the proposed dual-band BPF are detailed at the coupling–routing-diagram level and design guidelines for its transmission-line configuration are provided. Moreover, for experimental-validation purposes, a 1.57-GHz/2.38-GHz dual-band BPF microstrip prototype with symmetrical absolute bandwidths is manufactured and characterized.

A Millimeter-Wave Miniature Branch-Line Coupler in 22-nm CMOS Technology

A 60-GHz innovative quadrature branch-line coupler is proposed in this letter. The device was implemented in a 22-nm CMOS process, from global foundries. The proposed design merges two miniaturization techniques. On the one hand, slow-wave microstrip (SW-MS) lines based on bed of nails are demonstrated in CMOS technology for the first time. On the other hand, the two quarter-wavelength MS line sections required for the branch-line coupler implementation are realized using the SW-MS transmission line configurations with different form factors. As a result, the achieved miniaturization versus electrical performance is very good as compared to the state-of-the-art. Design insights addressing the coupler dimensions and losses are discussed. The experimental assessment shows an adequate frequency response with amplitude and phase imbalance of 0.8 dB and 1.8° at 60 GHz, respectively. The measured insertion loss is 2.35 dB at 60 GHz and the return loss is better than 15 dB at any port (from 54 to 66 GHz). The isolation is better than 15 dB (from 51 to 68 GHz). The overall size of the coupler is 0.3 mm $\times $ 0.22 mm, which is equivalent to $0.06 \cdot \lambda _{0} \times 0.044 \cdot {\lambda }_{0}$ , at 60 GHz.