Circuit Approach Research Articles

Electromagnetic Compatibility Analysis of Quadcopter UAVs Using the Equivalent Circuit Approach

Studying the electromagnetic compatibility of an Unmanned Aerial Vehicle (UAV) using full-wave electromagnetic simulations is computationally challenging. A UAV can exhibit unintentional coupling from far-field sources as well as from sources in its close vicinity. For example, in many applications, the UAV carries a payload that consists of a transmitting antenna to communicate/characterize receivers on the ground. Therefore, there is a strong need for an accurate and rapid technique to quantify RF coupling to the UAV subcomponents due to a wide range of incident electromagnetic radiation. In this work, we study RF coupling to a quadcopter UAV in a computationally efficient manner using the Equivalent Circuit Approach (ECA). The ECA is based on modeling the direct coupling to the wiring system with a Thevenin equivalent circuit terminated with the load under test. We study different circuit representations for this Thevenin equivalent circuit and show the advantages of each representation. Moreover, the equivalent circuit of the UAV wires is used to study different linear/nonlinear loads in a fraction of the time required by full-wave simulations. In addition, we show how the ECA provides physical insight that can facilitate the prediction of RF coupling to a UAV and other complex systems.

Understanding Switched-Flux Machines: A MMF-Permeance Model and Magnetic Equivalent Circuit Approach

Due to their particular structure, switched-flux permanent magnet machines have become a very interesting alternative for many applications. This is why some recent studies have been focused in the understanding of the operating mechanism of these machines via the MMF-permeance modelling. However, the models that can be found in the literature make some simplifications that reduce their accuracy when predicting the performance of switched-flux machines. For example, the models that can be found in the literature are commonly not precise enough for machines with a wide slot, because the influence of the modulator of the primary side of the machine is neglected. In this article, a precise analytical model is developed for a 6/13 C-Core switched-flux machine via a combination of a magnetic equivalent circuit and a MMF-permeance model. The model is based on the magnetic field modulation principle. The analytical model is used to explain the flux focusing effect and the force generation mechanism of switched-flux machines. A new concept of PM field harmonic efficiency ratio is used to identify the most efficient PM field harmonics of 2 switched-flux machines. The precision of the model is validated via 2D and 3D Finite Element Method simulations, and experimental measurements that were obtained with a linear machine prototype. The results show that the model can predict the performance of switched-flux machines with a high accuracy level.

The relation between Keynesian monetary theory and demand-led growth: a Sraffian exploration

This article integrates the Sraffian approach to demand-led growth theory with insights from Keynes’s concept of finance and from the monetary circuit approach. The paper’s first contribution is the extension of Garegnani’s interpretation of Keynes’s General Theory’s originality and limitations to Keynes’s 1937–1938 papers on ‘finance.’ In both cases, it is a question of freeing Keynes from the ties of Marginalist theory. Second, the paper identifies a complementarity between the Keynesian concept of finance, some insights from the monetary circuit, and the role attributed by the Sraffian take of demand-led growth to the autonomous components of demand, which are also Kalecki’s external markets. Finally, the authors propose a subsidiary role for the liquidity-preference theory in the context of the determination of the structure of interest rates, given the short-term base rate set by monetary authorities.

Management de la qualité du circuit des produits de santé expérimentaux dans les pharmacies hospitalières : enquête nationale et développement d’outils standardisés

Carry out a national inventory of the current situation regarding the quality management of the investigational health products circuit, to develop adapted standardised tools.A survey of 76 questions, developed by a regional working group, was conducted among clinical research pharmacists in French facilities. Tools were developed to meet the identified needs and validated by participating pharmacists, using the Delphi method. The consensus was defined by achieving a score above 80% on relevance, clarity and evaluability.Among 94 pharmacists participating in the survey, 88 were interested in standardised tools. The score for the implementation of a quality approach depended on the type of health facility (P<0.0005) and increased with the number of active trials (P<0.0005). All nine proposed tools were useful for over two thirds of pharmacists, but the self-assessment and audit grids have been prioritised. Indeed, only 26% of pharmacies carried out a prior risk assessment and 14% carried out internal audits. The review of both grids led to a consensus on 89% and 97% of the criteria respectively. The validated grids include 62 and 72 criteria respectively.The quality approach of the investigational health products circuit is heterogeneous in the participating centres, with a strong need for standardised tools. The two grids are relevant tools developed by and for professionals.The tools developed will enable to optimise the quality approach by identifying the non-conformities of the investigational health products circuit.

Accurate semi-numerical approach for multilayer metasurfaces with near-field coupling

Multilayer metasurfaces have attracted much attention for broad bandwidth and high transmission efficiency. However, the electromagnetic (EM) coupling will be significant and greatly affect the transmission performance when the inter-layer distance is in subwavelength scale. Here, we present a generally equivalent circuit approach (ECA) that can be used to investigate the transmission performance and the near-field coupling mechanism in multilayer metasurfaces. Based on the proposed ECA, the analytical expression of transmission coefficient is obtained. The accuracy of the circuit model is further verified by several typical multilayer metasurfaces in ultrawideband from 0 to 30 GHz. The proposed method is valid for an arbitrary multilayer metasurface system, regardless of the layer number and the metallic elements.

Design and Multi-Objective Optimization of a 12-Slot/10-Pole Integrated OBC Using Magnetic Equivalent Circuit Approach

Permanent magnet machines (PMs) equipped with fractional slot concentrated windings (FSCWs) have been preferably proposed for electric vehicle (EV) applications. Moreover, integrated on-board battery chargers (OBCs), which employ the powertrain elements in the charging process, promote the zero-emission future envisaged for transportation through the transition to EVs. Based on the available literature, the employed machine, as well as the adopted winding configuration, highly affects the performance of the integrated OBC. However, the optimal design of the FSCW-based PM machine in the charging mode of operation has not been conceived thus far. In this paper, the design and multi-objective optimization of an asymmetrical 12-slot/10-pole integrated OBC based on the efficient magnetic equivalent circuit (MEC) approach are presented, shedding light on machine performance during charging mode. An ‘initial’ surface-mounted PM (SPM) machine is first designed based on the magnetic equivalent circuit (MEC) model. Afterwards, a multi-objective genetic algorithm is utilized to define the optimal machine parameters. Finally, the optimal machine is compared to the ‘initial’ design using finite element (FE) simulations in order to validate the proposed optimization approach and to highlight the performance superiority of the optimal machine over its initial counterpart.

Systematic Design and Circuit Analysis of Lightning Impulse Voltage Generation on Low-Inductance Loads

The well-known circuit for the generation of lightning impulse voltage (LIV) on low-inductance loads was introduced by Glaninger in 1975, and the circuit component selection was proposed by Feser. However, the circuit and the approach for the component selection have some difficulties for which further adjustment is required for obtaining the waveform parameters according to the standard requirement. In this paper, an extended Glaninger’s circuit with an additional series resistor is proposed. Furthermore, a systematic design and circuit analysis of LIV generation for low-inductance loads are developed. With the help of a circuit simulator, the circuit analysis for the component selection is described. The validity of the proposed circuit was confirmed by some experimental results in comparison with the simulated ones. The proposed circuit and component selection provide not only the generation waveform according to the standard requirement but also other promising performances in terms of the wide inductance load range from 400 μH to 4 mH, a voltage efficiency of over 80%, an overshoot voltage of below 5%, an undershoot voltage of below 40%, and a maximum charging capacitance of 10 μF. From the simulated and experimental results, the proposed circuit and component selection approach is very useful for the LIV tests on low-inductance loads instead of using the conventional approach based on trial and error.

Intelligent Fault Detection and Identification Approach for Analog Electronic Circuits Based on Fuzzy Logic Classifier

Analog electronic circuits play an essential role in many industrial applications and control systems. The traditional way of diagnosing failures in such circuits can be an inaccurate and time-consuming process; therefore, it can affect the industrial outcome negatively. In this paper, an intelligent fault diagnosis and identification approach for analog electronic circuits is proposed and investigated. The proposed method relies on a simple statistical analysis approach of the frequency response of the analog circuit and a simple rule-based fuzzy logic classification model to detect and identify the faulty component in the circuit. The proposed approach is tested and evaluated using a commonly used low-pass filter circuit. The test result of the presented approach shows that it can identify the fault and detect the faulty component in the circuit with an average of 98% F-score accuracy. The proposed approach shows comparable performance to more intricate related works.

FLT3 OR CD33 NOT EMCN Logic Gated CAR-NK Cell Therapy (SENTI-202) for Precise Targeting of AML

Background: While chimeric antigen receptor (CAR) cell therapies have provided extraordinary clinical responses in some hematological malignancies, developing effective CAR cell therapies for acute myeloid leukemia (AML) has been challenging due to: (a) the lack of a single target antigen robustly expressed across both AML leukemic stem cell (LSC) and immature leukemic blast cell subpopulations, and (b) the lack of truly AML-specific target antigens, since current targets are also expressed on healthy tissues and may result in off-tumor toxicity. Using logic gated gene circuits, we are engineering our SENTI-202 CAR-NK cell therapy to overcome these long-standing challenges to treating AML patients.Methods: To maximize clearance of AML tumor subpopulations and minimize off-tissue toxicities, we used a proprietary bioinformatics paired antigen discovery platform to identify the optimal combinations of AML tumor-associated and healthy tissue antigens to target using an OR and NOT logic gated CAR gene circuit approach. The SENTI-202 therapeutic candidate is a FLT3 OR CD33 NOT Endomucin (EMCN) gene circuit-enabled allogeneic CAR-NK cell, designed to broadly target FLT3 and/or CD33-expressing AML tumor cells (including both LSCs and blasts) but not healthy hematopoietic stem cells (HSCs).Results: First, for the OR GATE portion of the logic circuit we demonstrated that engineered primary human NK cells expressing activating CARs (aCARs) that recognize both FLT3 and CD33 outperformed more traditional single target CAR approaches with FLT3 (p<0.05) or CD33 (p<0.01), and exhibited >80% cytotoxicity and significant cytokine secretion (GrB, IFN-g, and TNF-a) against multiple leukemia cell lines in vitro, including MOLM13, THP1, and SEM. We successfully engineered FLT3 OR CD33 CAR-NK cells using both bicistronic and bivalent CAR configurations, where bicistronic CARs possess separate FLT3 and CD33 CARs linked via a 2A peptide, and bivalent CARs use a loop structure to connect FLT3 and CD33 scFvs within the same CAR. While both approaches demonstrated robust efficacy against AML cells, the bivalent approach enabled greater CAR expression and cytotoxicity (p<0.05). Importantly, our FLT3 OR CD33 CAR-NK cells demonstrated significant cytotoxicity against primary AML patient samples (p<0.01-0.001) and significantly reduced tumor burden and improved mouse survival in MOLM13 (p<0.05) and MV4-11 (p<0.01) xenograft AML models. We believe that our strategy of concurrently targeting FLT3 and CD33 will result in a more robust synergistic anti-tumor effect, leading to a more durable remission with decreased risk of relapse due to single antigen escape.Second, for the NOT GATE portion of the logic circuit to protect healthy HSCs, we developed NK and T cell inhibitory CARs (iCARs) consisting of an scFv against a healthy cell antigen, hinge and transmembrane domains, and functional intracellular domains derived from inhibitory co-receptors containing immunoreceptor tyrosine-based inhibitory motifs. In the case of SENTI-202, the iCAR scFv recognizes EMCN, a surface antigen expressed on up to 76% of healthy HSCs but not on AML cells. Using two different iCAR configurations, we demonstrated that FLT3 (CD28z) aCAR-NK cells engineered with an EMCN-specific iCAR protected up to 67% (iCAR#1, p<0.01) or 50% (iCAR#2, p<0.01) of FLT3+ EMCN+ cells from FLT3 aCAR-mediated cytotoxicity. Next, to replicate a clinical context more closely, we mixed FLT3+ EMCN- (AML-like) and FLT3+ EMCN+ (HSC-like) target cells and demonstrated that FLT3 NOT EMCN CAR-NK cells exhibit preferential killing of FLT3+ EMCN- target cells (p<0.0001), demonstrating that our NOT GATED gene circuit controls NK-mediated responses on a cell-by-cell basis.Conclusion: SENTI-202 is a novel NK cell product candidate to be engineered with both OR and NOT logic gated CAR gene circuits, wherein the OR gate is designed to increase AML LSC/blast tumor clearance (to prevent relapse), and the NOT gate is designed to protect healthy HSCs from off-tumor toxicity, enabling regeneration of a healthy hematopoietic system and mitigating the need for a bone marrow transplant. Beyond AML, OR and NOT logic gated CAR-NK cell therapy has applicability to other cancer-associated antigen targets that are potentially limited by antigen escape and/or off-tumor toxicity, increasing the potential for enhanced efficacy and reduced risk of undesirable side effects. DisclosuresNo relevant conflicts of interest to declare.

Levitation Performances Analysis of a Novel Bearingless Switched Reluctance Motor

To deal with the coupling between the levitation force and torque, a new bearingless switched reluctance motor (BSRM) is presented in the paper, in which the torque flux is separated with the levitation flux. In addition, due to the low cost and power of the three-phase power converter, the radial levitation of the proposed BSRM is driven by a three-phase power converter. The structure of the proposed BSRM is first introduced. The mathematical models of radial levitation force are second established by employing equivalent magnetic circuit approach. Finally, the electromagnetic characteristics of the BSRM, such as flux field distribution, transient levitation force and force-current relationship are investigated through the MagNet 3D. The research results indicate that the novel structure has good performances.

Synthesizing Electrically Equivalent Circuits for Use in Electrochemical Impedance Spectroscopy through Grammatical Evolution

Electrochemical impedance spectroscopy (EIS) is an important electrochemical technique that is used to detect changes and ongoing processes in a given material. The main challenge of EIS is interpreting the collected measurements, which can be performed in several ways. This article focuses on the electrical equivalent circuit (EEC) approach and uses grammatical evolution to automatically construct an EEC that produces an AC response that corresponds to one obtained by the measured electrochemical process(es). For fitting purposes, synthetic measurements and data from measurements in a realistic environment were used. In order to be able to faithfully fit realistic data from measurements, a new circuit element (ZARC) had to be implemented and integrated into the SPICE simulator, which was used for evaluating EECs. Not only is the presented approach able to automatically (i.e., with almost no user input) produce a more than satisfactory EEC for each of the datasets, but it also can also generate completely new EEC configurations. These new configurations may help researchers to find some new, previously overlooked ongoing electrochemical processes.

(Invited) Through-Silicon Via Copper Plating and Endpoint Detection

Heterogenous, 2.5D, and 3D integration provide solutions for making microelectronics systems more compact and improving their performance. Cu-filled through-silicon vias (TSVs) are an important interconnect technology for these advanced integration techniques. TSV design and geometry (overall size, aspect ratio, and pitch) depend on the intended microelectronics application. Standard integrated circuit (IC) approaches often utilize high density vias that are achieved through substrate thinning; however, some applications need large-scale vias (≥ 600 µm deep). For example, some microelectromechanical systems (MEMS) applications need full wafer thickness vias due to die thickness specifications, and high-power devices can either employ large-scale vias or via arrays for current requirements and thermal management constraints. Cu deposition fill profile is sensitive to applied voltage or current, electrolyte composition and concentrations, and feature geometry; therefore, deposition processes must be tuned specifically for each via geometry. This work outlines Cu deposition process development and filling results for full wafer thickness TSV geometries in a suppressor-based electrolyte consisting of copper sulfate, sulfuric acid, potassium chloride, and Tetronic 701 suppressor, [i] according to the S-shaped Negative Differential Resistance (S-NDR) mechanism. [ii],[iii] During these TSV filling experiments, unique features in the electrical data were observed that signify completion of Cu plating in the vias. A novel endpoint detection method was derived from these data to determine when vias are filled. [i] Analogous endpoint detection through electrical signals has been previously observed for bottom-up Au filling of high aspect ratio trenches. [iv] During voltage-controlled via filling, as the Cu electrodeposit approaches the top of the TSVs, current can be monitored for a slight rise (due to increased metal ion transport and plating rate high up in the features), followed by a current local minimum (caused by adsorbed suppressor molecules that impede Cu deposition at the top of the vias). These characteristic features in the electrical data can be used to determine via filling completion. A similar technique can be used during current-controlled filling, where voltage data are monitored for a voltage maximum, which indicates that the Cu electrodeposit has reached the top of the features. Current work involves development of an automated method to recognize these electrical endpoint signals and terminate deposition when the vias are filled. This endpoint detection method has potential to greatly enhance microelectronics manufacturing by providing geometry-independent process control, improving manufacturing repeatability, decreasing sensitivity to changes in electrolyte over time, and reducing the time involved in subsequent processing steps through minimizing Cu overburden formation.Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA-0003525. SAND2021-5013 A [i] R. P. Schmitt et al 2020 J. Electrochem. Soc. 167 162517. [ii] D. Josell and T. P. Moffat 2016 ECS Trans. 75 15. [iii] D. Josell and T. P. Moffat 2018 J. Electrochem. Soc. 165 D23. [iv] S. Ambrozik et al 2019 J. Electrochem. Soc. 166 D443.

Backscatter Communications

This paper addresses backscatter communications as a new paradigm for Internet of Things (IoT) sensor wireless solutions. The paper clearly presents the history background of the technology and then makes a summary of the more recent developments form several groups around the world, with emphasis in US and Europe groups. The analysis done in this paper will address circuit and physical layer approaches for such a solution and its real implementations, having in mind IoT sensors for long range high speed communications.

Automatically differentiable quantum circuit for many-qubit state preparation

Constructing quantum circuits for efficient state preparation belongs to the central topics in the field of quantum information and computation. As the number of qubits grows fast, methods to derive large-scale quantum circuits are strongly desired. In this work, we propose the automatically differentiable quantum circuit (ADQC) approach to efficiently prepare arbitrary quantum many-qubit states. A key ingredient is to introduce the latent gates whose decompositions give the unitary gates that form the quantum circuit. The circuit is optimized by updating the latent gates using back propagation to minimize the distance between the evolved and target states. Taking the ground states of quantum lattice models and random matrix product states as examples, with the number of qubits where processing the full coefficients is unlikely, ADQC obtains high fidelities with small numbers of layers $N_L \sim O(1)$. Superior accuracy is reached compared with the existing state-preparation approach based on the matrix product disentangler. The parameter complexity of MPS can be significantly reduced by ADQC with the compression ratio $r \sim O(10^{-3})$. Our work sheds light on the "intelligent construction" of quantum circuits for many-qubit systems by combining with the machine learning methods.

The effects of geometrical parameters on resonance frequency of Inverted Split Ring Resonators (ISRRs)

In this study, an inverted split ring resonator (ISRR) was designed and the effects of the design geometrical parameters on the resonance frequency presented by using an equivalent circuit approach. The width of the rings, w, the width of ring split, s, and the outer length of the resonator, lres were chosen as geometrical parameters. The determined designs were implemented by making simulations with electromagnetic design software, and the numerically obtained results were compared with theoretically obtained results. A good agreement of simulation and theoretical results was achieved and presented.

Low power ASK modulator based on direct injection‐locked current reuse VCO in 130‐nm CMOS technology for high data rate RFID applications

AbstractA low power consumption Amplitude Shift Keying (ASK) modulator employing current reuse cross‐coupled (CRC) LC‐VCO topology and direct injection locking (IL) technique at 10.5‐GHz frequency is presented in this paper. The modulator consumes 864 μW with a DC supply of 1.2 V drawing an average current of 720 μA. The differential VCO is composed of a PMOS‐NMOS pair in stacked series cross‐coupled connection enabling current reuse which results in reduction of the average current drawn from the power source. For comparison, the ASK modulator is also realized with conventional cross‐coupled (CC) topology using NMOS pair. Both circuit approaches are carried out in GF 130‐nm CMOS technology and the post‐layout simulation results of 0.5 × 0.5 mm2 integrated circuits (ICs) show that the CRC topology consumes less power and half of the average current compared to CC topology. Owing to low power requirements, the CRC ASK modulator can be used in self‐powered active Radio Frequency Identification (RFID) tag transmitters for higher data rates.

Characterization of Electromagnetic Device by Means of Spice Models

— In this paper, the lumped parameter circuital approach devoted to the simulation of massive, conductive, and ferromagnetic cores including eddy currents and nonlinearity is presented. In the first part of the paper, the circuit analogies devoted to the simulation of magnetic structure coupled with external electrical and eventually mechanical equations are summarised. The two techniques are known in the literature as reluctance-resistance and permeancecapacitance analogies. In particular, it is put in evidence the exploitation of the gyrator component in the modelling of the coupling among magnetic and electrical quantities. The originality of this paper consists in demonstrating for the first time that the rotator-capacitor approach is very suitable for simulations in spice environment and the solution is validated on real applications. Following the circuital approach, the effect of the conductivity and nonlinear magnetic behaviour of the magnetic branches is formalized and introduced in the model. The simulation of the conductivity behaviour, which introduces in massive cores significant eddy current effects, is modelled according to the two possible analogies: the reluctance and the permeance-capacitor model. Under sinusoidal steady-state behaviour, energy aspects related to the two models are then presented and discussed. The nonlinearity is taken into account through the fixed-point technique which is suitable for a lumped circuit representation. The full circuital approach is then adopted for the simulation of the real electromechanical actuator under transient and sinusoidal steady-state behaviour conditions. The simulated result is then compared with numerical finite element and experimental result

LOW POWER VERY LARGE SCALE INTEGRATION (VLSI) DESIGN OF FINITE IMPULSE RESPONSE (FIR) FILTER FOR BIOMEDICAL IMAGING APPLICATION

Nowadays, the medical image processing techniques are using Very Large Scale Integrated (VLSI) designs for improving the availability and applicability. The digital filters are important module of Digital Signal Processing (DSP) based systems. Existing Finite Impulse Response (FIR) design approach performed with Partial Full Adder (PFA) based Carry Lookahead Adder (CLA) and parallel prefix adder logic in Vedic multiplier. Objective of this approach is to improve the performance of VLSI circuit by obtaining the result of area, power and delay, also, effective incorporation between VLSI circuit and image processing approach makes improved application availability. The design of high speed digital FIR filter is designed with various adders and multipliers. The incorporation of VLSI design and image processing techniques are used on biomedical imaging applications. The Enhanced FIR filter design utilized the hybrid adder and adaptive Vedic multiplier approaches for increasing the performance of VLSI part and the image processing results are taken from Matrix Laboratory tool. This proposed FIR filter design helps to perform the biomedical imaging techniques. The simulation result obtains the performance of enhanced FIR with area, delay and power; for biomedical imaging, Mean Square Error (MSE) and Peak Signal to Noise Ratio (PSNR) is obtained. Comparing with existing and proposed method, the proposed FIR filter for biomedical imaging application obtains the better result. Thus the design model states with various application availability of VLSI image processing approaches and it obtains the better performance results of both VLSI and image processing applications. Overall, the proposed system is designed by Xilinx ISE 14.5 and the synthesized result is done with ModelSim. Here the biomedical image performance is done by using MATLAB with the adaptation of 2018a. Keywords- Enhanced FIR filter; Adaptive vedic multiplier; Hybrid adder; Biomedical imaging; power delay product;

Equivalent Circuit Approach for Beam–Wave Interaction Analysis of MILO

The beam–wave interaction analysis in the RF interaction structure of magnetically insulated line oscillator (MILO) is presented. The analysis is carried out using the linearized Vlasov equation by considering the equivalent circuit approach. Taking into account, the beam present dispersion relation is derived to obtain the temporal growth rate and oscillation frequency. In addition, the RF energy stored and power transfer through the slow wave structure during beam–wave interaction process are calculated. Considering the imaginary part of admittance and coupling coefficient of the cavity, the expression for energy stored and power transfer to the load is also derived. The dispersion relation for electron beam interaction with the phase velocity of the oscillating mode, through the slow wave structure, is explained. Furthermore, the derived analytical results temporal growth rate, RF energy, and output power are validated through reported methods (field analysis and particle-in-cell (PIC) simulation). The results are in agreement with the reported results using the field analysis case.

Equivalent Circuit Approach for Output Characteristic Design of Capacitive Power Transfer

A simple equivalent circuit of the capacitive coupler and the compensator topology is presented to provide a design procedure for a capacitive power transfer (CPT) system. After that, the voltage gain curve is plotted to analyze the output characteristic of the CPT. This approach is needed in the frequency-controlled CPT stage without any post-regulator, since the output has to be operated in some charging characteristics, such as the load-independent constant current (CC) and constant voltage (CV) outputs that strongly rely on the gain curve design. Therefore, the circuit derivation and the gain curve plot is presented in this brief. Finally, the four-plate compact CPT design with LCL-compensated topology with 100 V output voltage and 450 W output power is experimentally tested to verify the design approach. The plate air-gap distance is 50 mm, and the maximum efficiency of the proposed system is 72%.