International Journal of Numerical Modelling-Electronic Networks Devices and Fields最新文献

{"title":"New Approach to Design Resistorless Electronically Tunable Grounded Capacitance Multipliers Using CMOS VDIBAs","authors":"Ajishek Raj,&nbsp; Suryakant,&nbsp;K. L. Pushkar,&nbsp;Manoj Kumar","doi":"10.1002/jnm.70120","DOIUrl":"https://doi.org/10.1002/jnm.70120","url":null,"abstract":"<div>\u0000 \u0000 <p>Capacitance multipliers are essential in applications requiring large capacitance but constrained by size, cost, or integration feasibility. Their ability to simulate high-value capacitors using active components makes them crucial in modern ICs, power electronics, biomedical devices, wireless communication, and sensor interfaces. This paper presents a novel approach for designing resistorless grounded capacitance multiplier (GCM) circuits. The proposed design employs the voltage differencing inverting buffered amplifier (VDIBA) as the active block, leading to the introduction of 18 new GCM circuits. These circuits utilize two VDIBAs and a single capacitor, enabling both positive and negative capacitance multiplication factors (MFs). The MF of all the presented circuits can be electronically tuned using bias voltages and also have independent control. The design eliminates stringent matching constraints, enhancing practical feasibility. Furthermore, the impact of nonideal VDIBA parasitics on circuit performance is thoroughly analyzed and compared with ideal values. To validate the proposed approach, the circuits are applied in the design of a first-order low-pass filter (LPF). Their functionality is further confirmed through a CMOS-based VDIBA implementation using 0.18 μm TSMC technology parameters in PSPICE simulations. Comprehensive analyses, including frequency and transient response, Monte Carlo analysis, process corner evaluation, and temperature variation, demonstrate the robustness of the circuits. The proposed GCM circuits operate over a wide frequency range from 1 mHz to 0.1 GHz, making them suitable for applications such as signal processing, impedance matching, and noise filtering. The capacitance can be enhanced up to 20 times its original value, while the circuit consumes approximately 1.5 mW of power. Experimental frequency response of an application example of a LPF using a VDIBA, implemented with commercially available ICs CA3080 and AD830, is also provided.</p>\u0000 </div>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":"38 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Surrogate-Based Adaptive Sampling Approach for Electromagnetic Problems","authors":"Emmanouil Karantoumanis,&nbsp;Theodoros Zygiridis,&nbsp;Nikolaos Ploskas","doi":"10.1002/jnm.70121","DOIUrl":"https://doi.org/10.1002/jnm.70121","url":null,"abstract":"<p>Black-box optimization problems arise in many real-world applications, where the objective function is unknown or computationally expensive to evaluate. In electromagnetic engineering, optimization tasks often involve complex structures and materials, making direct analytical solutions infeasible. These problems are further complicated by high-dimensional search spaces, the need for numerous simulations, and the absence of explicit derivative information. Gradient-based optimization methods are often impractical due to the lack of gradients and high evaluation costs. Even derivative-free optimization (DFO) techniques may struggle with efficiency in high dimensions. To address these challenges, we implement a surrogate-based adaptive sampling DFO approach that refines a surrogate model while optimizing black-box electromagnetic problems. We focus on deterministic black-box functions with noise-free evaluations. Our methodology is demonstrated in two case studies: optimizing the reflection coefficient in a partially filled waveguide and the transmission properties of a multilayered dielectric filter. We compare our method against Monte Carlo, Polynomial Chaos, Genetic Algorithms, and Particle Swarm Optimization. We confirm that our approach achieves a better solution while maintaining high accuracy in the surrogate model, with significantly fewer simulations. For the waveguide problem, our method achieved a best value of 0.1325 using only 168 simulations, compared to 0.1374 with 100 million Monte Carlo samples and 0.1469 with 9180 Polynomial Chaos evaluations. In the filter case, we obtained 1.7113 GHz using 240 simulations, outperforming the 1.7682 GHz result from 5370 Polynomial Chaos samples. These results demonstrate a simulation cost reduction of over 95%–98%, while achieving improved optimization performance.</p>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":"38 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jnm.70121","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis, Simulation and Design of Ternary Logic Circuits Based on CNTFETs in Verilog-A","authors":"Roberto Marani,&nbsp;Anna Gina Perri","doi":"10.1002/jnm.70122","DOIUrl":"https://doi.org/10.1002/jnm.70122","url":null,"abstract":"<div>\u0000 \u0000 <p>The field of portable electronics and smart devices has seen a significant shift toward multi-valued logic (MVL), especially ternary logic, due to its potential to reduce circuit complexity and power consumption. This paper shows how Carbon Nanotubes FETs (CNTFETs) can be used in the design of ternary logic gates, which is a promising alternative to the conventional binary logic design. In particular, we propose a procedure to design CNTFET-based NOR/NAND gates and a Decoder, all in ternary logic, and the proposed method allows us to evaluate the propagation delay. Comparing the proposed design with the existing design, the delay times are reduced by approximately 80%. Moreover, the main novelty is that in this paper all simulations are performed in Verilog-A, thus avoiding the problems presented in SPICE. The obtained results are encouraging and demonstrate that CNTFET-based ternary logic gates can be a viable approach for the design of low-power, high-speed circuits.</p>\u0000 </div>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":"38 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solving Nonlinear Volterra Integro-Differential Equations in the Mechanical Model of Inelastic Cables Under the Influence of Loads","authors":"Yaser Rostami,&nbsp;Khosrow Maleknejad","doi":"10.1002/jnm.70115","DOIUrl":"https://doi.org/10.1002/jnm.70115","url":null,"abstract":"<div>\u0000 \u0000 <p>In this work, two approximation techniques are presented for solving nonlinear Volterra integro-differential equations with boundary conditions, arising in the modeling of inelastic cables subjected to external loads. The foundation of the required numerical computation is established through the operational matrices of interpolating basis functions and the Gegenbauer wavelet technique, which transform the original problem into a system of algebraic equations. To construct the interpolation basis functions, orthonormal Lagrangian basis functions are employed. Subsequently, the resulting algebraic system is solved using Newton–Cotes nodes to obtain the desired numerical solution. The use of operational matrices simplifies the problem and significantly reduces the computational complexity of solving integro-differential equations. Moreover, error bounds are established, and a comprehensive convergence analysis of the proposed methods is carried out. Finally, numerical experiments supported by graphical illustrations clearly demonstrate the reliability and computational efficiency of the developed techniques.</p>\u0000 </div>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":"38 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145146386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effectiveness of the Thermal via in GaN HEMT Studied by a Co-Simulation Approach","authors":"Amir Murtadha Mohamad Yussof,&nbsp;Mohd Faizol Abdullah,&nbsp;Norazreen Abd Aziz","doi":"10.1002/jnm.70118","DOIUrl":"https://doi.org/10.1002/jnm.70118","url":null,"abstract":"<div>\u0000 \u0000 <p>This article evaluates the effectiveness of polycrystalline diamond (PCD) thermal vias in mitigating self-heating issues in the two-dimensional electron gas (2DEG) layer of GaN high-electron mobility transistors (HEMTs). Thermal simulations conducted using Silvaco Victory Device identified and characterized hotspots within the 2DEG layer, which were further analyzed using Ansys Icepak. For GaN-on-sapphire HEMTs, the integration of PCD thermal vias resulted in a significant reduction of up to 23.5% in hotspot temperatures, with optimal performance observed when the thermal via protruded into the GaN layer. Even when the thermal via terminated at the GaN/sapphire interface, it still demonstrated substantial thermal management benefits. In contrast, for GaN-on-Si and GaN-on-SiC HEMTs, the effectiveness of PCD thermal vias was notably diminished. This is attributed to the higher thermal conductivities of Si (148 Wm⁻¹ K⁻¹) and SiC (490 Wm⁻¹ K⁻¹) compared to sapphire (23 Wm⁻¹ K⁻¹), limiting the potential for hotspot temperature reduction despite using high-quality PCD (1000 Wm⁻¹ K⁻¹). These results significantly extend existing thermal management studies by uniquely addressing the thermal challenges posed by GaN-on-sapphire substrates through the introduction of PCD thermal vias, a substrate-material combination that has not been comprehensively explored in prior research. The findings highlight that while PCD thermal vias offer substantial improvements in thermal management for GaN-on-sapphire HEMTs, their impact is less pronounced for GaN-on-Si and GaN-on-SiC HEMTs. A preliminary cost–benefit analysis suggests that while PCD thermal vias have a higher initial cost, their long-term reliability and reduction in thermal-induced failures make them a cost-effective solution. Future work will focus on experimental validation and exploring alternative thermal management strategies such as microchannel cooling and advanced thermal interface materials.</p>\u0000 </div>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":"38 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145101783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Electromagnetic Property Variations in Breast Tissue Liquid Phantoms and Models on the Performance of UWB Radiofrequency Tumor Detection Systems","authors":"Marwa Slimi,&nbsp;Bassem Jmai,&nbsp;Paulo Mateus Mendes,&nbsp;Ali Gharsallah","doi":"10.1002/jnm.70119","DOIUrl":"https://doi.org/10.1002/jnm.70119","url":null,"abstract":"<div>\u0000 \u0000 <p>As in many medical device systems development, the design of radiofrequency breast tumor detection systems undergoes a test phase based on the use of liquid phantoms. It is well known the difficulty in obtaining phantoms that precisely model each tissue for each frequency of interest while keeping such properties for a long time. Despite the many available studies using such phantoms, limited information is available on a systematic analysis of the effect that the use of an imprecise phantom may have on the characterization of radiofrequency systems. This work presents the design and fabrication of ultra-wideband liquid breast and tumor phantoms. The main issue with this approach is that incorrect phantom properties, as well as an incorrect frequency response, lead to assessment errors. The current research focus is mainly focused on the model of the phantom, rather than its electromagnetic properties. Typically, the EM properties of breast phantoms are accurate only in a small frequency range, and these properties are frequency dependent. To address this issue, we validated a homogeneous breast phantom with good results in terms of dielectric permittivity (1.613% &lt; error &lt; 3.22%) and loss tangent (error &lt; 33%) in the wide frequency range of [1–6] GHz. The proposed phantom retains its properties for a significant period of time, degrading only 6.78% in 2 h after fabrication while exposed to the environment. When it is stored in a container, only a small variation of ±1.7% was registered after 9 months.</p>\u0000 </div>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":"38 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145101580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling of Wireless Temperature Sensors Based on Coded SAW Delay Lines for RF Identification","authors":"Rafik Serhane,&nbsp;Nabila Belkhelfa,&nbsp;Nadir Maghlaoui,&nbsp;Fahima Arab,&nbsp;Abdenacer Assali","doi":"10.1002/jnm.70117","DOIUrl":"https://doi.org/10.1002/jnm.70117","url":null,"abstract":"<div>\u0000 \u0000 <p>Wireless identified Surface acoustic waves (SAWs) sensors operating in the real-time offer a wide range of applications. The novelty of this paper is the use of two-dimensional (2D) COMSOL FEM modelling of two types of one-port reflective SAW delay lines (DL): a simple reflective one designed with conventional Bragg reflectors and a coded reflective one that employs a specific spatial distribution of Bragg mirrors to encode the SAW electrical response for radio frequency identification (RFID). The SAW structures are made of Al/AlN/Si stratified layers, forming respectively the IDT electrodes, the piezoelectric layer, and the substrate. The geometry and materials are selected to achieve a SAW device operating frequency around 441.2 MHz. The reflection scattering parameters of all the studied structures are calculated in the frequency domain <i>S</i>₁₁(<i>f</i>) and transformed to the time domain <i>S</i>₁₁(<i>t</i>) by performing an inverse Fourier transform (IFFT). In the coded reflective delay line structure, eight Bragg systems containing eight reflectors each are employed to generate the 10010110 code. This structure is tested as a temperature sensor; its normalized sensitivity in the temperature range of −25°C to 200°C is evaluated at −25.39 ppm/°C. The tag sensor's identification procedure is performed by using the cross-correlation technique on two RFID temperature sensors interrogated simultaneously: namely, one coded 10010110 and another one coded 11010111.</p>\u0000 </div>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":"38 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145101559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Graphite-Inspired Dumbbell-Shaped Single Radiator MIMO Antenna for THz Regime: A Frequency Switchable/Reconfigurable Approach","authors":"Mayuri Kulshreshtha,&nbsp;Rajarshi Bhattacharya","doi":"10.1002/jnm.70101","DOIUrl":"https://doi.org/10.1002/jnm.70101","url":null,"abstract":"<div>\u0000 \u0000 <p>A graphite-inspired frequency switchable/reconfigurable MIMO (Multiple-input multiple-output) antenna is implemented for THz applications. Reconfigurability in the frequency response is achieved by layering the graphite in the slot of Antenna-2. The proposed antenna provides isolation better than 30 dB, high efficiency, and reasonable gain in the resonating band. An impedance bandwidth of 11.5% (2.04–2.29 THz) &amp; 15.6% (4.06–4.74 THz) for Antenna-2 and 12.5% (3.53–3.99 THz) for Antenna-3 is achieved. Both the presented antennas demonstrate excellent diversity performance like Envelope Correlation Coefficient (ECC) &lt; 0.03, Directive Gain (DG) &gt; 9.95 dB; Total Active Reflection Coefficient (TARC) &lt; −10 dB, and Channel Capacity Loss (CCL) &lt; 0.35 bits/s/Hz, that can be incorporated into biomedical applications, high-frequency telecommunications, sensing applications, biological and astrophysical insights.</p>\u0000 </div>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":"38 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145101860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Nature, Root-Cause, and Elimination of Ground Resonances in a Transmission-Line Based Connector With Guard Traces","authors":"Navid Elahi,&nbsp;Jian-Ming Jin","doi":"10.1002/jnm.70116","DOIUrl":"https://doi.org/10.1002/jnm.70116","url":null,"abstract":"<p>In this paper, we investigate the important phenomenon of “ground resonance” in a transmission-line based connector with guard traces added for crosstalk reduction. Through a modal analysis, we analyze the phase differences between the differential signal mode on the transmission line and differential ground mode introduced with the addition of guard traces that are also known as ground lines. We show that the so-called “ground resonance” is due to the phase difference between the two modes, which causes the reflection of the combined field, instead of the ground mode alone, at the ends of the connector. With this revelation, we propose three methods based on two approaches to eliminating ground resonances to reduce the insertion loss and crosstalk in a connector with multiple transmission lines. One approach is to modify the configuration of the two ends of the guard traces to reduce the phase difference between the signal and ground modes, and the other approach is to compensate for the phase difference by changing the propagation velocity of the signal mode. We demonstrate the effectiveness of these approaches through numerical simulation of two connectors: one based on the microstrip structure and the other based on the coplanar structure, with both a single differential pair and two adjacent differential pairs considered.</p>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":"38 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jnm.70116","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145058017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Impact of Pore Diameters, Pore Randomness, and Void Fraction on the EMI Shielding of Polyurethane Foams","authors":"Ahmad Mamoun Khamis,&nbsp;Isabelle Huynen","doi":"10.1002/jnm.70111","DOIUrl":"https://doi.org/10.1002/jnm.70111","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents a novel approach to analyze the electromagnetic interference (EMI) shielding effectiveness (SE) of polyurethane (PU) foam geometries, which are built in Blender software and simulated using CST Studio software. Three different batches of geometries were built to investigate the impact of pore diameters, pore randomness, and void fraction of PU foam on the SE, reflection coefficient (<i>S</i>₁₁), and electromagnetic absorption in the 26.5–40 GHz frequency range. The observed resonance frequency decreased with decreasing pore diameters and void fraction. Decreasing the pore diameter, increasing the pore randomness, and decreasing the void fraction enhanced the SE in the frequency range between the resonance frequency and 40 GHz. The EM absorption increased with increasing the pore diameter and randomness but decreased with increasing the void fraction. This study also presents simulations and measurements of Polytetrafluoroethylene (PTFE) and PU foam materials. The simulation results were compared with the measured ones obtained using vector network analyzer measurements to verify CST Studio's ability to accurately calculate the EM parameters. The measured and simulated results were in good agreement, confirming the accuracy of the results obtained using CST Studio. Our new parametric study fills a gap in existing literature since it combines for the first time an open-source 3D software for 3D rendering with an electromagnetic simulator to evaluate the impact of the pore topography (void fraction, diameter, randomness, etc.) on the EMI shielding performance of PU foams.</p>\u0000 </div>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":"38 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145012412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}