{"title":"A High Power Density Ku-Band GaN Power Amplifier Based on Device-Level Thermal Analysis","authors":"Jiuding Zhou, Chupeng Yi, Wenliang Liu, Yang Lu, Xiaohua Ma, Yuanfu Zhao, Yue Hao","doi":"10.1002/jnm.3311","DOIUrl":"https://doi.org/10.1002/jnm.3311","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper introduces a new design method for a high-power density GaN MMIC amplifier operating in the Ku-band. A thermal model to investigate the thermal distribution of power amplifiers is proposed to achieve optimal performance in terms of power density, chip size, and channel temperature. The thermal distribution and channel temperature of a single device, an eight-way parallel device combination, and the entire PA layout are obtained by finite element simulation. The thermal coupling effects of high-power MMICs are analyzed in detail. The thermal resistances are extracted from the simulation to design a Ku-band amplifier. Measurement results demonstrate that the designed amplifier achieves 43.0–44.2 dBm output power and 22.7%–34.5% PAE at 28 V drain voltage with a 100 μs pulse width and 10% duty cycle within 12–18 GHz. The proposed design method enables the amplifier to have a compact layout of 10.88 mm<sup>2</sup> and a power density between 1.84 and 2.42 W/mm. This design method can offer valuable insights for future development of high-power MMIC amplifiers.</p>\u0000 </div>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":"37 6","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664798","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":"One-Step Leapfrog 3D Split-Field FDTD Method for Periodic Structures at Oblique Incidence","authors":"Lingpu Zhang, Juan Chen, Chunhui Mou, Ao Peng","doi":"10.1002/jnm.3315","DOIUrl":"https://doi.org/10.1002/jnm.3315","url":null,"abstract":"<div>\u0000 \u0000 <p>This article introduces a one-step leapfrog three-dimensional (3D) split-field finite-difference time-domain (SF-FDTD) method designed for analyzing periodic structures under oblique incidence, aiming to improve computational efficiency. Initially, it introduces new variables to substitute the field components postsplitting. After that, it applies time-centered approximate difference method to precisely adjust the time step for each iteration. It eliminates the need for empirical coefficients when performing calculations with lossy materials. Finally, it derives the implementation of the convolutional perfectly matched layer (CPML) for the proposed method. The proposed method is both easier to implement and more resource-efficient, significantly cutting down CPU usage and memory consumption. Numerical results confirm its improved efficiency.</p>\u0000 </div>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":"37 6","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664802","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":"Static Approximate Modified Mirror—Full Adder for High Speed and Low Power Operations Using 32 nm CNTFET Technology","authors":"Sagar Juneja, M. Elangovan, Kulbhushan Sharma","doi":"10.1002/jnm.3320","DOIUrl":"https://doi.org/10.1002/jnm.3320","url":null,"abstract":"<div>\u0000 \u0000 <p>The error tolerance nature of the digital multimedia applications enables the implementation of approximate digital circuits to achieve the benefits of high speed of operation and low power consumption. This paper proposes a static approximate modified mirror full adder (SAMM-FA) circuit designed using logic level approximation to reduce the number of transistors in the circuit. Owing to the balanced electrical characteristics, better stability and higher on-current to off-current ratio (<i>I</i><sub>on</sub>/<i>I</i><sub>off</sub>), 32 nm carbon nanotube field effect transistor (CNTFET) technology has been used for implementing the proposed circuit in the Cadence Virtuoso tool. Featuring only 10 transistors and operating at a supply voltage of 0.5 V, the proposed SAMM-FA has a low power dissipation of just 4.14 nW, and propagation delay of just 3.82 ps. The power delay product and energy delay product figure of merits of the proposed circuit are found to be excellent when compared with the contemporary designs.</p>\u0000 </div>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":"37 6","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664930","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}
Salisu Ibrahim, Salah Boulaaras, Abedallah Rababah, Mujahid Iqbal
{"title":"Explicit Commutativity for Lamé Linear Time-Varying Differential Systems","authors":"Salisu Ibrahim, Salah Boulaaras, Abedallah Rababah, Mujahid Iqbal","doi":"10.1002/jnm.3309","DOIUrl":"https://doi.org/10.1002/jnm.3309","url":null,"abstract":"<div>\u0000 \u0000 <p>This article studies the commutativity and sensitivity of the Lamé linear time-varying systems (LTVSs), and investigates the effects of disturbances on such systems. The commutative pair for the Lamé LTVS <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>A</mi>\u0000 </mrow>\u0000 <annotation>$$ A $$</annotation>\u0000 </semantics></math> of order <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 <annotation>$$ 2 $$</annotation>\u0000 </semantics></math> is found, that is, a new Lamé LTVS <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>B</mi>\u0000 </mrow>\u0000 <annotation>$$ B $$</annotation>\u0000 </semantics></math> of order <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>m</mi>\u0000 <mo>≤</mo>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 <annotation>$$ mle 2 $$</annotation>\u0000 </semantics></math> is derived using the explicit commutative theories for zero initial conditions (ICs). For the case of nonzero ICs, the commutativity between the connected input–output of Lamé systems <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>AB</mi>\u0000 </mrow>\u0000 <annotation>$$ AB $$</annotation>\u0000 </semantics></math> and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>BA</mi>\u0000 </mrow>\u0000 <annotation>$$ BA $$</annotation>\u0000 </semantics></math> is studied. New and simple explicit commutative theories and conditions for second-order LTVSs are derived, simplifying the use of commutativity for practical and industrial scenarios. These findings enable us to analyse the commutativity, sensitivity, robustness and stability of Lamé systems, and to determine the effects of disturbances. The explicit results presented in this article are supported by simulations and verified by examples and constitute a significant contribution to science and engineering applications.</p>\u0000 </div>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":"37 6","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664943","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":"Numerical Technique Based on Operational Matrices of Fractional Integration Using \u0000 \u0000 \u0000 ψ\u0000 \u0000 $$ psi $$\u0000 -Shifted Chebyshev Polynomials","authors":"Shazia Sadiq, Mujeeb ur Rehman","doi":"10.1002/jnm.3314","DOIUrl":"https://doi.org/10.1002/jnm.3314","url":null,"abstract":"<div>\u0000 \u0000 <p>In this paper, we present a numerical scheme based on a modified form of shifted Chebyshev polynomials to find the numerical solution of a class of fractional differential equations. For this purpose, we work out operational matrices of fractional integration of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>ψ</mi>\u0000 </mrow>\u0000 <annotation>$$ psi $$</annotation>\u0000 </semantics></math>-shifted Chebyshev polynomials obtained from shifted Chebyshev polynomials. Finally, the solution to the problem under consideration is obtained by solving a system of algebraic equations that results from the use of operational matrices of integration. The analysis of integer and non-integer order differential equations is presented to show the convergence of the solution of fractional order differential equation to the corresponding solution of the integer order differential equation. At the end, we present some linear and non-linear examples to validate the theoretical analysis. Non-linear examples are solved using Quasilinearization and proposed numerical technique.</p>\u0000 </div>","PeriodicalId":50300,"journal":{"name":"International Journal of Numerical Modelling-Electronic Networks Devices and Fields","volume":"37 6","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664945","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}