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A novel hybrid bandpass filter (BPF) with wideband and high selectivity is proposed in this paper. The hybrid BPF is composed of two film bulk acoustic resonator (FBAR) cells and three lumped component resonators realized by the integrated passive device (IPD) technology. The ABCD matrix to S-parameters matrix method is used to calculate the frequency response of the BPF. Moreover, the expressions of transmission zeros (TZs) have been extracted. In the design process, an iterative design approach is proposed to improve the circuit and layout of the hybrid filter based on the packaged acoustic-electric hybrid simulation effect. Finally, two parts of the filter are packaged based on the flip-chip method, and two prototypes for the BPF are measured. The measured results of two chips with 3 dB fractional bandwidth of 13.7% and 15.8% are designed and fabricated, which verifies the validity of the proposed design principle. [ABSTRACT FROM AUTHOR]

With the fast growth of electronic technology today, the hybrid circuit of analog and digital circuits has become a trend in the growth of electronic technology. To address fault diagnosis in analog circuits, Haar wavelet is applied for fault feature extraction. The K-means clustering method and pseudoinverse algorithm were used to optimize the center value and weight value of the radial basis function neural network, respectively. The adaptive step size was improved in the wolf pack algorithm, the parameters of the radial basis function neural network were optimized based on the wolf pack algorithm, and a wolf pack algorithm optimized radial basis function neural network model was constructed. The test results show that this model converges after 40 times of training, with an error value of 10−3 and an average value of the mean squared error of 0.45. Comparing the fault diagnosis rates of the original model, genetic algorithm optimized radial basis function neural network model, and wolf colony algorithm optimized radial basis function neural network model, the last model has the best fault diagnosis rate, reaching 95.52%. The wolf colony algorithm is utilized to optimize the radial basis function neural network model to diagnose the faults in the standard filter circuit, and the fault diagnosis rate reaches 96.17%. The findings express that the radial basis function neural network model optimized by the wolf colony algorithm has a good diagnosis effect for different faults in the analog circuit. [ABSTRACT FROM AUTHOR]

In recent years, low-voltage direct current (LVDC) microgrids are becoming more attractive because they represent a solution to integrate renewable sources, storage, and electronic loads bringing some advantages in comparison with traditional AC grids. However, the protection of such a network involves many challenges, especially in the case of LVDC microgrids with more than one feeder and multiple energy sources. Indeed, the traditional protection breakers used for an AC grid cannot isolate the faults and protect the components of a DC grid, while the use of solid-state circuit breakers increases energy losses. This paper deals with the analysis and design of the protection schemes for LVDC microgrids through the combination of mechanical circuit breakers and hybrid circuit breakers. This solution has the advantage of energy loss reduction but introduces further issues due to the slow transition times of the mechanical circuit breakers. Thus, a completely decentralized control system capable of overcoming the fast fault-clearing time, cost-effectiveness, and selectivity issues is designed to protect from pole-to-pole faults. The proposed control strategy is compared with a centralized protection scheme available in the literature through numerical simulation. The two algorithms show similar performances, with a mean voltage dip duration of less than 30 ms and a maximum voltage dip duration of about 100 ms in the most severe fault condition, but the proposed solution is more reliable and flexible since it does not depend on the communication system. [ABSTRACT FROM AUTHOR]

This article shows the complete analysis and design for a Q/V (46‐52 GHz) band wideband analog predistorter (APD). First, the reflection coefficient for hybrid coupler's through port with complex impedance is corrected. Second, the acceptable error region is introduced to analyze the influence of different nonlinear loads. Levenberg‐Marquardt algorithm is then used to solve the circuit parameters of the hybrid T matching network. Finally, a Q/V band (46‐52 GHz) wideband APD is fabricated and measured. The measurement results are in good agreement with the analysis results. Furthermore, the linearized traveling‐wave tube amplifiers (TWTA) gain compression is less than 0.5 dB, and the phase change of TWTA after linearization is less than 4°. The C/IM3 shows more than 10 dB improvement. [ABSTRACT FROM AUTHOR]

Background: The use of extracorporeal circulation (ECC) for intraoperative cardiopulmonary support during lung transplantation has been increasing in the recent years. Our group previously described a novel hybrid extracorporeal membrane oxygenation (ECMO) circuit for use in lung transplantation. Technique: Our approach for intraoperative management of our novel hybrid ECMO circuit for lung transplantation is driven by two main goals: The first is to deliver management that ensures an appropriate balance between the native and ECMO cardiac outputs in order to provide a stable environment that promotes attenuation of ischemic‐reperfusion injury during implantation. The second is to provide a stable hemodynamic environment that results in an appropriate global perfusion guided by multiple monitors and an organ systems‐based approach during implantation. Comments: Our novel technique for intraoperative management of this circuit during lung transplantation is described. [ABSTRACT FROM AUTHOR]

Summary: The key obstacle in the realization of multiterminal high‐voltage direct current (MTDC) grids is the lack of existing commercial protection that a device can withstand the DC fault. Although different HVDC circuit breaker technologies have been investigated and demonstrators tested by manufacturers, the innovation of such devices to ensure a reliable protection system has not been proven yet due to the maximum breaking capability limitation especially in MTDC grids. To this, a combination of superconducting fault current limiter (SFCL) technology with a fast DC circuit breaker could bring a solution to this bottleneck. In this work, a new application of an accurate model of resistive‐type SFCL (rSFCL) considering both the electrical and thermal behaviors is proposed to work together with a proactive hybrid DC circuit breaker (PHCB) to fulfill the whole system protection. The viability of the proposed approach is verified under a worst DC fault case‐scenario that imposed in a five‐terminal MTDC meshed grid. The numerical analysis and simulations are carried out using (EMTP‐rv) software, while the obtained results show how significantly the proposed rSFCL can reduce the fault current and enhance the breaking capability. Also, a positive interaction has been observed between the rSFCL and PHCB in terms of design sizing and operation performance. [ABSTRACT FROM AUTHOR]

This paper presents, for the first time, the hybrid use of loading techniques (which involve terminating the spiral arms with different structures to give a resistive or capacitive effect) and a novel technique of cavity groove in order to enhance the performance of two-arm, cavity-backed, 2–18 GHz spiral antenna. The antenna is made on Duroid 5880 and has the smallest form factor (50 mm diameter), meeting all the performance metrics, which are targeted for efficient performance of a spiral antenna for ultra-wideband (UWB) applications. Measured results match the simulated results and show that by the utilization of hybrid loading and cavity groove, the gain is increased by a factor of 3.65 dBi and the axial ratio is improved by 2.73 dB at (2 GHz) as compared to a simple Archimedean antenna made on Duroid 5880, without increasing the size. The proposed antenna shows 2.25 dB more gain and improved axial ratio performance as compared to a simple Archimedean spiral antenna made on Tmm4, without the utilization of the hybrid techniques proposed earlier in the literature. [ABSTRACT FROM AUTHOR]

This paper examines the interval forecasting of carbon futures prices in one of the most important carbon futures market. Specifically, the purpose of this study is to present a novel hybrid approach, which is composed of multioutput support vector regression (MSVR) and particle swarm optimization (PSO), in the task of forecasting the highest and lowest prices of carbon futures on the next trading day. Furthermore, we set out to investigate if considering some potential predictors, which have strong influence on carbon futures prices, in modeling process is useful for achieving better prediction performance. Aiming at testing its effectiveness, we benchmark the forecasting performance of our approach against four competitors. The daily interval prices of carbon futures contracts traded in the Intercontinental Futures Exchange from August 12, 2010, to November 13, 2014, are used as the experiment dataset. The statistical significance of the interval forecasts is examined. The proposed hybrid approach is found to demonstrate the higher forecasting performance relative to all other competitors. Our application offers practitioners a promising set of results with interval forecasting in carbon futures market. [ABSTRACT FROM AUTHOR]

In this article, a crossed dipole antenna with compact size (43 × 43 mm2) and high isolation (42 dB) is proposed using a hybrid balun circuit. The hybrid balun consists of a tapered balun and a Marchand balun. The tapered balun transforms the microstrip line into the parallel feeding lines for one pair of dipoles, and the Marchand balun transforms the stripline transmission line into a couple of out‐of‐phase feeding lines for the crossed pair of dipoles. Due to the low coupling between two different baluns, a high isolation of the antenna can be achieved when the crossed dipole antenna is cascaded with the hybrid balun. Moreover, these two baluns can improve impedance matching and therefore further miniaturize the size of the crossed dipole antenna. The impedance matching of two baluns can be controlled and adjusted independently. As a result, the proposed dual‐polarized antenna has the bandwidth of 1.7 to 2.8 GHz for S11 < −15 dB with compact size and high isolation. The proposed antenna with the hybrid balun circuit are fabricated, and the simulated and measured results meet well. [ABSTRACT FROM AUTHOR]