With the rapid development of 5G technology, key components like Surface Acoustic Wave Filters (SAWF) face challenges in bandwidth, spurious, and leakage. This paper optimizes the materials, thickness, and metallization ratio (MR) of IDT to propose a high-frequency, low-spurious, wide-bandwidth filter for the N78 band. Firstly, simulations show Au outperforms Al and Cu in reducing spurious and leakage. Secondly, by analyzing impact of MR, the optimal MR for series and parallel resonant units is 0.4 and 0.6, respectively. Eventually, A filter with 642 MHz bandwidth, 3.52 GHz center frequency, and 1.22 dB in-band spurious was obtained for N78 band.

This study proposes an automated fault diagnosis method for switch faults in three-phase inverters, based on current waveform feature extraction. The research focuses on analyzing three-phase output current waveforms under different fault conditions, including open-circuit fault (OCF), short-circuit fault (SCF), gate driver fault (GDF), and aging (AGN). Multiple key indicators such as average current, root mean square (RMS) current, peak-to-peak value, and Park’s current are extracted, and two normalized current indices are proposed as the basis for fault identification. The proposed approach can be seamlessly integrated into existing current sensors and control algorithms, requiring only minimal software adjustments. Moreover, the method is robust and applicable under varying conditions consistently achieving high diagnostic accuracy.

A terahertz-wave subharmonic mixer receiving RF input and local oscillator (LO) signals from the opposite side of a planar antenna was developed based on epi-layer-transferred Fermi-level managed barrier diodes on a SiC substrate. The developed mixer mounted on a Si hyper-hemispherical lens with a transimpedance amplifier exhibited a minimum noise-equivalent power as low as 6 × 10^-19 W/Hz at RF and LO frequencies of 306 and 151 GHz, respectively. Comparison of signal-introduction configurations revealed that a single planar antenna simultaneously acted as an antenna for RF and LO signals as well as a signal combiner for mixing detection.

Lateral overflow integration capacitor (LOFIC) CMOS image sensors (CISs) can realize high-dynamic-range (HDR) imaging by combining high-conversion-gain (HCG) signal with low-conversion-gain (LCG) signal. However, LOFIC CISs require an analog-to-digital converter (ADC) and SRAM for both HCG and LCG signals, leading to higher power consumption and a larger circuit area compared to standard-dynamic-range (SDR) CISs. To address this issue, we propose a single-channel readout circuit for the LOFIC pixel with selector for HCG and LCG signals. When the HCG signal is selected, the A/D conversion of the LCG signal is halted, reducing the power consumption by 11.3% on average. Furthermore, SRAM stores only the selected signal, reducing the readout circuit area by 7.9%. A test chip of the readout circuit was fabricated with a 0.18 μm CMOS process. The dark noise of the HCG signal and the maximum charge of the LCG signal were respectively estimated to be 4.0 e^-_rms and 130 ke^-, corresponding to a dynamic range of 90.2 dB.

In this letter, a wideband 180° hybrid coupler with unequal power division ratio and inputs absorptive behaviors is proposed, which consists of a slotline-based four-port network (FPN) and two absorptive cells. The slotline-based FPN is implemented by four transmission line sections, a slotline resonator, two microstrip/slotline transitions and a shunted open-circuit stub, which can achieve wideband isolation and unequal power division. Both absorptive cells are composed of a coupled line and a resistor-loaded shorted stub, which can not only enhance the bandwidth of the hybrid coupler, but also achieve inputs absorptive behaviors for both Port 1 and Port 4. Explicit design equations and detailed analysis are given and discussed. Meanwhile, a prototype with unequal power division ratio of 1:2 and absorptive bandwidth of 200% is selected for design, fabrication and measurement. Finally, the excellent agreement between the EM simulated results and the measured results verifies the effectiveness of the design.

In this letter, a novel load design space is proposed based on the resistance-resistance series of continuous modes (Res.-Res. SCMs) for designing high-efficiency power amplifiers (PAs) with multi-octave. By introducing a phase shift parameter into the voltage waveform expression of Res.-Res. SCMs, the load design space is expanded, enabling greater design flexibility and bandwidth enhancement. To validate the proposed approach, a multi-octave PA was designed and implemented using a GaN HEMT. Measurement results show that the PA achieves a drain efficiency (DE) of 55.3-73.9%, an output power of 38.7-41.2 dBm, and a gain of 9.7-12.2 dB across 0.5-3.9 GHz, corresponding to a relative bandwidth of 154.5%.

This paper proposes an improved high-order compensation bandgap reference (BGR) for high-precision applications, addressing the limitations of traditional linearized VBE in accurately modeling high-order temperature nonlinearity. The circuit consists of a bandgap circuit, a start-up circuit, and a trimming circuit. A zero temperature coefficient (TC) current flowing through the high-order compensation Bipolar Junction Transistor (BJT) is guaranteed by adding an operational amplifier (op-amp). Reasonable design and a trimming circuit make the high-order compensation branch current equal to the proportional-to-absolute-temperature (PTAT) current. The proposed BGR is fabricated with a 0.18-μm process, with a supply voltage of 1.8 V, and has the layout area of 220×123 μm². Measurement results show a TC of 5.19 ppm/°C over the -40°C to 125°C, a Line Regulation (LR) of 0.2632% for supply voltage from 1.55 V to 2 V, and a power consumption of 159.21 μW.

A compact tri-band bandpass filter based on spoof surface plasmon polaritons (SSPPs) is proposed. The design utilizes an SSPP unit cell that combines short-circuited and open-circuited stubs to support the fundamental mode and two high-order modes, enabling tri-band filtering. Independent bandwidth design is realized during the design stage by precisely adjusting specific geometric parameters. A prototype was fabricated and measured, with results showing excellent agreement with simulations, confirming the accuracy and effectiveness of the design. The filter exhibits low insertion loss, independently designed bandwidths, and a compact size, making it suitable for modern multi-band wireless communication systems.

This study provides a tracking and pre-sampling (TPS) technique which drives successive approximation register (SAR) analog-to-digital converters (ADC) with small input current. And the principle of TPS technique is demonstrated by means of complex frequency domain analysis. In contrast with two traditional SAR ADCs, the simulation results of matlab and cadence indicate the SAR ADC with TPS technique reduces both transient and average input current significantly, whether under DC or cosine wave input voltages.

Paralleling SiC MOSFETs has been demonstrated to enhance the rated current and power of an inverter; however, the phenomenon of unbalanced currents during conduction and shutdown imposes heightened demands on the safety of a parallel SiC MOSFET system. The utilization of SiC MOSFET gate driving strategies is of paramount importance for the efficient parallelization of SiC MOSFETs, with a significant impact on their drain-source current balance. In this paper, the effect of the symmetry of drive and power circuits on the generation of unbalanced currents between parallel SiC MOSFETs is theoretically analyzed. Then, double-pulse experiments of parallel SiC MOSFETs with one-to-many passive driver (O-T-M) and one-to-one isolated driver (O-T-O) strategies were conducted under different driving loop and power loop symmetric conditions. And the appropriate parallel working conditions for each driving strategy are obtained. A differential mode choke-based square is proposed as a solution to the unbalanced current problem of O-T-M. Under certain operating conditions, the method can achieve well-balanced flow, as verified by power and drive loop asymmetry experiments.

We propose a fast simulation method for calculating the electric field strength under reverse bias in junction termination extension (JTE), a termination structure used in vertical power devices. In the conventional simulation method, the electrostatic potential, electron density, and hole density are solved simultaneously using three coupled equations. In contrast, the proposed method expresses electron and hole densities as functions of the potential, allowing the electric field strength to be determined by solving only the potential equation. We evaluate the proposed method for the termination structure of GaN vertical power devices and demonstrate that it achieves faster calculations than the conventional method. Furthermore, we demonstrate that the proposed method achieves sufficient accuracy for practical applications in calculating the electric field distribution by neglecting the computation of minority carriers, whose impact on the electric field strength is negligible.

The conventional three closed-loop proportional-integral (PI) control system in permanent magnet synchronous motor (PMSM) servo control necessitates the precise determination of PI parameters for each loop, as these parameters critically influence control accuracy and system stability. Currently, the selection of PI parameters for the three closed loops often relies on human intervention or subjective expertise, which can lead to inefficiencies and inconsistencies. To overcome this limitation, this study proposes a fully autonomous PI parameter self-tuning method. The method employs a layered tuning approach: the current loop parameters are optimized using an internal model control strategy, prioritizing fast servo tracking response; the speed loop parameters are derived by establishing a relationship between servo tracking speed response frequency and system stability; and the position loop parameters are determined using the residue transformation method of the Z-inverse transform, aiming to minimize the tracking error for instantaneous ramp inputs. Due to the gradual variation of motor parameters caused by environmental temperature fluctuations, the parameters involved in this method can be sequentially identified using the recursive least squares (RLS) algorithm. Specifically, only one parameter is estimated at a time, while the remaining parameters are held constant. Once the motor parameters and speed requirements are specified, this method autonomously determines the PI control parameters for the PMSM servo system, enabling automatic optimization and tuning of control parameters. This approach facilitates intelligent and adaptive PMSM servo control. The effectiveness of the proposed method is validated through experimental results, demonstrating its practical applicability in engineering contexts.

Fault-tolerant and redundant power supplies are often used in systems that require high reliability, such as data servers, telecommunications, and power supplies for autonomous driving function. Using diode is a simple method to keep uninterrupted power supply that is, using diode in series with each power path to become “Diode ORing”. However, in high current application, the voltage drop of the diode will result huge power loss. Even if that a low voltage drop of Schottky diode is adopted. This article proposes a simple P MOSFET control circuit that can implement the function of P MOSFET as a diode, that is, to ensure unidirectional conduction of current and maintain a low conduction voltage drop, thereby reducing losses. The circuit has the advantages of low forward voltage drop, without IC control, no need for additional auxiliary power supply, and the ability to block current flow between different power supplies that is the reverse current blocking is achieved. A circuit for implementing ORing of two power supplies to increase system redundancy or power capacity is provided. Simulation results verify the feasibility of the proposed control circuit.