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 of a single device, an eight-way parallel device combination, and the entire PA layout are obtained by finite element simulation. The channel temperature characteristics of the single device, eight-way parallel device combination, and the entire PA are compared under pulse excitation. 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 2 and a power density between 1.84 W/mm and 2.42 W/mm. This design method can offer valuable insights for future development of high-power MMIC amplifiers.

Various test structures can be used to determine the specific contact resistivity of ohmic contacts. The transmission line model test structure and circular transmission line model test structure are the most commonly used. The analytical expressions of the former are straightforward and effectively describe the electrical behavior of a contact, while the concentric geometry of the latter eliminates complications during fabrication. In this paper, we present a hybrid test structure that combines the advantages of the transmission line and the circular transmission line models. The analytical expressions of the new structure are presented, and its finite-element modeling is undertaken. The effect of contact geometry on this test structure is also discussed. Using the presented test structure, determining contact parameters does not require any error corrections.

Recently, antiferroelectric and antiferroelectric-like materials have regained interest for electronic devices, such as field-effect transistors, memory, and transducers. Particularly, in micro/nano-electromechanical coupling systems, such as actuators, these innovative materials, with their peculiar phase transition between antiferroelectric and ferroelectric phases, show promise in offering large electro-strain, fast response, and low power consumption devices. However, compared to the numerous computational models of ferroelectric actuators, numerical modeling of antiferroelectric and antiferroelectric-like actuators remains relatively unexplored. In this paper, we propose a phenomenological model of a uni-axial antiferroelectric and antiferroelectric-like actuators based on their switching polarization behavior. Specifically, both the double hysteresis loop of antiferroelectric materials and the pinched hysteresis loop of antiferroelectric-like materials can be captured by two hyperbolic tangent functions. This allows us to cast a polarization-dependent strain and piezoelectric tensor into the constitutive laws. The proposed model is then implemented into a finite element framework, in which the voltage-induced deformation can be solved using the Newton-Raphson procedure. Numerical examples of both antiferroelectric and antiferroelectric-like actuators are illustrated and compared with experimental data, showing our proposed model can serve as a useful tool for the design and development of antiferroelectric and antiferroelectric-like actuators.

This paper proposes a new methodology for sensitivity analysis evaluation, fast and with high precision of the electric potential distribution near the transmission lines (TL’s). The TL is modeled by the finite element method and the sensitivity of the cable positions is obtained using the adjoint method. The sensitivity of the objective function during the optimization process by using methods based on gradient information is obtained by using the adjoint method. The exact sensitivity obtained by the adjoint method concerning the numeric model of the TL’s results in new geometries of the bundles conductors with high surge impedance loading. These geometries are not possible to get using analytic models. The sensitivities of a large number of conductors by phase are obtained with high precision and very low computational cost using adjoint sensitivities, which are independent of the number of design variables. The central finite difference (CFD) method is used to calculate the sensitivities and to validate the adjoint method. With this methodology, the FEM model of the TL can be used during the optimization process without compromising the required computational processing time.

This paper has designed a bandpass filter using a coplanar stripline stub (CPS) resonator consisting of open and short-ended strip lines connected to the PIN Diode switches. The use of spurline stub resonators inside CPS results in bandpass and bandstop filters, depending on the PIN diode switch configurations. The work presents a novel circuit architecture aimed at reducing parasitic resonance of the spurline resonators and acquire the necessary series stub characteristics. The proposed filter resonates at 6.9-9 GHz and 1.7-4.7 GHz, and 8.4 GHz when the PIN diodes are forward and reverse-biased, respectively. It also resonates at 1-2.1 GHz, 4.8-5.3 GHz, and 6.9-9 GHz when one diode is reverse-biased, and the other is connected in forward bias. An insertion loss below -0.55 dB and a return loss less than 10dB have been obtained during simulation and measurement. The designed filter can find different applications for the 1.8 GHz GSM band, 2.4/5.8GHz (WLAN), 3.6 GHz (WiMAX), Long Term Evolution (LTE), and WIFI. The filter can be used in various multi-frequency systems owing to its compact size. The measured and simulated findings of the proposed CPS spurline stub resonator wideband bandpass filters are substantially consistent.

A new temperature noise model, including the influence of gate-drain series resistance Rgd on the noise performance for an InP HEMT, is presented in this paper. An equivalent temperature Tgd of Rgd has been taken into account based on pospieszalski’s noise model. The corresponding extraction procedure of noise parameters is given. Good correlation between the simulated and measured noise parameters in the frequency range of 8GHz~50GHz for a wide range of bias points verify the validity of the improved noise model.

This paper presents a new approach to nanoparticle detection using an active micro-resonator operating in the transparency regime. Simulations demonstrate that when nanoparticles interact with the micro-resonator surface, they induce optical losses. To compensate for these losses, the optical gain is amplified to restore the transparency regime. Simulation results show a linear relationship between nanoparticle concentration and the pump power required to compensate for optical losses. By the use of micro-resonator with a very high quality factor, this approach offers an accurate and sensitive method for detecting nanoparticles, without the need for complex equipment.

In this work, the harmonic balance approach is applied to a 2D non linear finite-element magnetic model with motion, coupled to a non linear circuit. The case study comprises a six-pole three-phase surface-mounted permanent magnet generator connected to a six-pulse full-wave diode bridge rectifier. Simulations are performed at fixed generator speed in two operating cases: with a open-circuit DC bus and supplying a load resistance. Both time stepping and harmonic balance approaches are deeply discussed focusing on the model under study, along with relevant implementation details. Harmonic balance results are compared with benchmark time stepping simulations in terms of voltage and current waveforms, progressively expanding the harmonic spectrum. The computational cost of the two approaches is reported as well. Simulation accuracy is satisfying with regard to time stepping benchmark results: relative errors on total harmonic distortion and global root-mean-square values are lower than 3% and 1%, respectively. However, the time stepping approach outperforms the harmonic balance one, due to the relatively short initial transient of the chosen case study. Further improvements on practical implementation are needed to exploit the potentialities of harmonic balance technique.

The development of SAW transducers requires a series of steps ranging from material selection, geometry design, as well as, the selection of fabrication techniques for their characterization and validation process. Here, we use the finite element method in COMSOL Multiphysics to present a methodology and a detailed analysis of the design of a SAW transducer in a delay line configuration. First, we simulate single-finger and double-finger configurations of IDTs on LiNbO3 in 64°YX and LiNbO3 128°YX orientation, with the objective of 1) comparing the simulation results with the analytical delta model to validate the simulation process, presenting Pearson correlation values ranging from 0. 76 to 0.84. 2) calculate a maximum frequency value obtainable for those configurations from a resolution of 5 microns in the photolithography technique, used for the fabrication of SAW transducers. Next, we extended the analysis to study a specific transducer design made to operate at a resonant frequency of 97 MHz. In order to determine the influence of piezoelectric material and IDT configuration we compared identical designs on 128°YX and 64°YX orientations of LiNbO3 with single and double finger configurations and adding the SPUDT configuration. We observed the best results for the single-finger IDT configuration in 128°YX LiNbO3 orientation compared to the other variants through its insertion loss level of -7.29 dB, its average sidelobe level of 18.63 dB, and its average transition band slope for the main lobe of 119.59 dB/MHz. The results obtained can serve as a guide for new researchers or students to expand the use of numerical tools in the design of SAW transducers and SAW devices.

This paper aims to propose a novel method for designing an SRAM cell using an Etched Drain based Cyl. GAA TFET with a hetero-substrate material and an elevated density strip. The aim is to reduce power dissipation and improve stability, as demonstrated through analysis utilizing SNM as well as N-Curve methods. With respect to the 16nm MOSFET based SRAM cell, the proposed device-based SRAM cell shows significant improvements with a 68.305% reduction in leakage power, a 15.58% increase in SVNM, an 8.623% increase in SINM, an 8.152% increase in WTV, a 12.86% increase in WTI, a 27.62% increase in SPNM, and a 19.95% increase in WTP. The design is implemented and analyzed using Cadence Virtuoso software, and a novel approach of look up tables and Verilog A is utilized for the device to circuit application. These results indicate promising advancements in the design of SRAM cells, which could have significant implications for the development of advanced computer systems.

This work presents an investigation on the numerical simulation of a layered piezoelectric system using the complex finite element method (ZFEM). This approach allows the standard FEM solution to provide information about the design sensitivity of the mechanical displacement and voltage potential fields with respect to small variations in the material properties of the system. The layered body is formed by PZT-4 and PZT-5 stacked together. Results show that the design sensitivities of the soft grounded piezoelectric are larger compared to those of PZT-4 for the specific configuration analyzed. For solution verification purposes. The standard steady state solution was compared against a commercial FEM package and the error obtained was less than 4%.

In the upcoming epochs, conventional energy may deplete soon. Thus, the use of conventional energy in the power industries need to be supplemented by non-conventional energy resources. This would result in loss of synchronisms in the power grids owing to the fact that solar and wind alternate their attributes expeditiously with change in atmospheric phenomenon. To ameliorate frequency deviation within a specific range automatic generation control (AGC) implements forced allowance on system operation. A three area thermal with photovoltaic (PV), electric vehicle (EV), wind system is considered under deregulated environment to develop and to judge the efficacy of newly developed cascade fractional order hybrid controller combination of (FOTID & 3DOF-PID). Comparing the aforementioned controller to other controllers such as the three degree of freedom proportional-integral-derivative (3DOF-PID), the fractional order tilt-integral-derivative (FOTID), and the proportional-integral-derivative (PID) justifies the system’s effectiveness. This assessment has been accomplished by a trendy optimization technique such as hybrid whale optimization algorithm (HWOT). However, the main intent of this write-up is to fabricate a cascade fractional order (CC-FO) hybrid controller that would act as the new control mechanism for the proposed system under deregulated scenario. It has been found that the suggested CC-FO hybrid controller stabilises the system ( i.e., Under step load disruptions, frequency deviation and tie-line power become zero) in the shortest amount of time possible. Additionally, it is seen that the recommended controller can control a wide range of nominal loading circumstances and system characteristics, demonstrating its robustness.

In this article, the performance analysis of recessed gate and field-plated III-nitride Nano-HEMT (High Electron Mobility Transistor) developed on β-Ga 2O 3 substrate with and without AlN spacer layer is studied. The two-dimensional electron gas (2DEG) formed at the AlGaN/GaN interface is crucial in changing the characteristics of AlGaN/GaN HEMTs. The different transport, DC, and AC characteristics of the proposed III-nitride HEMT with spacer layer are numerically simulated and compared with the HEMT without spacer layer. The major findings of this research demonstrate that the AlN spacer layers large band off set, strong polarisation field, and high barrier allow the increased concentration of 2DEG, when it is introduced between AlGaN/GaN interface. Furthermore, the AlN layer moves the 2DEG distribution shifts from the surface, which diminishes interface scattering. Further, AlN thickness variation influences the polarisation field and conduction band offset, which impacts the concentration and mobility of 2DEG.