Search Results (55)

To meet the increasingly strict requirements of modern communication, radar detection and electronic measurement systems for wide-bandwidth, low-insertion-loss and high-isolation signal routing, this paper presents a 16 × 16 programmable switch matrix that simultaneously achieves wideband operation (DC-40 GHz), low insertion loss (≤0.9 dB maximum), high isolation (>50 dB typical), and systematic modular scalability, a combination not found in existing implementations. The matrix, constructed with high-quality coaxial switches and optimized RF circuitry and electromagnetic structures, provides flexible and stable single-pole multi-throw (SPMT) signal routing across an ultra-wide frequency range from DC to 40 GHz. The switch matrix features a modular architecture, integrating multiple RF switching units, drive control circuits, and communication interface modules. This architecture achieves minimal signal path depth while maintaining full connectivity between any input and output port, directly minimizing cumulative insertion loss. Through precise impedance matching design and isolation structure optimization, the system still exhibits outstanding transmission characteristics at the 40 GHz high-frequency end: typical insertion loss does not exceed 0.9 dB, and the isolation between channels is better than 50 dB, effectively ensuring the integrity of signals in complex multi-channel environments. To meet the requirements of automated testing and remote control, the equipment integrates dual communication interfaces (serial port/network port), supports the SCPI command set and TCP/IP protocol, and can be conveniently embedded in various test platforms to achieve instrument interconnection and test process automation. Experimental verification shows that this matrix exhibits excellent switching stability and signal consistency across the entire 40 GHz, with a switching action time of less than 10 ms. Furthermore, it is capable of real-time topology reconfiguration via a microcontroller or FPGA. These innovations collectively deliver a switch matrix that meets the demanding requirements of 5G communication, millimeter-wave radar, and aerospace defense systems—applications where bandwidth, signal integrity, and system flexibility are paramount. Full article

Wireless power transfer (WPT) systems have garnered significant market attention owing to their broad applicability in portable electronic devices, electric vehicles, unmanned aerial vehicles, biomedical implants, and related fields. In these systems, operating frequency and efficiency are critical factors affecting both transmission efficiency and transmission distance, making high-frequency operation an important trend for improving overall WPT performance. However, elevating the switching frequency also introduces notable challenges, including increased switching losses in power devices, limited load adaptability, and poor anti-misalignment capability, which in practice often lead to degraded system efficiency and unsatisfactory waveform quality. Accordingly, this paper proposes a high-frequency inverter power supply system capable of operating at a maximum output voltage frequency of 25 KHz. Under conditions of a 10 KHz output frequency and a 20 KΩ load, the system achieves a peak efficiency of 94.01%. A prototype was implemented through the integration of a software algorithm based on ARM Cortex-M3 core control with a hardware architecture consisting of a driving circuit, a full-bridge inverter, and a switchable filtering module. This work offers practical design insights for the development of future high-frequency, high-voltage inverter systems, while also providing valuable experimental data to support further research in this area. Full article

This paper presents a high-efficiency wireless power transfer (WPT) architecture employing a resonant inductive coupling to power smart sensor nodes in remote or sealed environments, where conventional power delivery is unfeasible. The system integrates a photovoltaic (PV) energy source with a step-down DC-DC converter based on the LM2596 buck regulator to adjust the voltage from the PV. The proposed conditioned power system supplies the entire electronic circuit consisting of a PWM modulator based on an NE555, which drives an IR2110 gate driver connected to a Class D power amplifier. The amplifier excites a pair of high-Q resonant coils designed for mid-range inductive coupling. On the receiver side, the inductively coupled AC signal is rectified and regulated through an AC-DC conversion stage to charge a secondary energy storage unit. The design eliminates the need for physical electrical connections, ensuring efficient, contactless energy transfer. The proposed system operates at a resonant frequency of 24.46 kHz and achieves up to 80% transmission efficiency at a distance of 113 mm. The receiver provides a regulated DC output between 4.80 V and 4.97 V, sufficient to power low-consumption smart sensors. Full article

Gynecological cancers remain a major global health burden due to their high incidence, molecular heterogeneity, and frequent resistance to conventional therapies. Beyond well-established genetic alterations and targeted treatments, growing attention has been directed toward the role of cancer stem cells (CSCs), a rare tumor subpopulation with self-renewal, differentiation, and tumor-initiating capacities. CSCs are sustained by a specialized microenvironment, the cancer stem cell niche, where growth factors, cytokines, hypoxia, and stromal interactions converge to promote stemness, chemoresistance, and metastatic potential. In breast cancer, signaling axes such as EGFR, IGF, TGFβ, and HGF/c-Met critically regulate CSC expansion, particularly in aggressive subtypes like triple-negative tumors. In ovarian cancer, factors including HGF, VEGFA, IGF, and stromal-derived BMPs drive CSC plasticity and contribute to relapse after platinum therapy. Endometrial CSCs are supported by pathways involving TGFβ, BMP2, and Netrin-4/c-Myc signaling, while in cervical cancer, VEGF, IGF-1, Gremlin-1, and TGFβ-mediated circuits enhance stem-like phenotypes and drug resistance. Cytokine-driven inflammation, especially via IL-3, IL-6, IL-8, IL-10, and CCL5, further fosters CSC survival and immune evasion across gynecologic malignancies. Preclinical studies demonstrate that targeting growth factors and cytokine signaling, through monoclonal antibodies, receptor inhibitors, small molecules, or cytokine modulation, can reduce CSC frequency, restore chemosensitivity, and enhance immunotherapy efficacy. This review highlights the interplay between CSCs, growth factors, and cytokines as central to tumor progression and relapses, emphasizing their translational potential as therapeutic targets in precision oncology for gynecological cancers. Full article

This paper presents a comprehensive comparative analysis of high-voltage, high-frequency pulse generation techniques for Pockels cell drivers. These drivers are critical in electro-optic systems for laser modulation, where nanosecond-scale voltage pulses with amplitudes of several kilovolts are required. The study reviews key design challenges, with particular emphasis on thermal management strategies, including air, liquid, solid-state, and phase-change cooling methods. Different high-voltage, high-frequency pulse generation architectures including vacuum tubes, voltage multipliers, Marx generators, Blumlein structures, pulse-forming networks, Tesla transformers, switching-mode power supplies, solid-state switches, and high-voltage operational amplifiers are systematically evaluated with respect to cost, complexity, stability, and their suitability for driving capacitive loads. The analysis highlights hybrid approaches that integrate solid-state switching with modular multipliers or pulse-forming circuits as offering the best balance of efficiency, compactness, and reliability. The findings provide practical guidelines for developing next-generation high-performance Pockels cell drivers optimized for advanced optical and laser applications. Full article

Accurate prediction and efficient suppression of conducted electromagnetic interference(EMI) in electric drive systems(EDS) are achieved through an innovative technique proposed in this paper, leveraging a key path impedance characteristic model. The influence of critical components—namely; three-phase alternating current modules; motors; and insulated gate bipolar transistor drive parameters—on EMI is meticulously analyzed by establishing a current spectrum characteristic analysis model of the critical path impedance. This study calculates current characteristic curves under varying filter parameters for interference suppression, while voltage characteristic curves are computed based on a comprehensive electric drive system model. The mapping relationship between current and voltage spectrum characteristics is scrutinized, revealing a high consistency between the model’s current spectrum curves and the conducted interference voltage spectrum. This alignment enables precise prediction of risk frequency points. Moreover, the critical path impedance model remarkably enhances computational efficiency by 87.5%, thereby facilitating an efficient evaluation and design of EMI suppression in electric drive systems. The proposed technique effectively reconciles the incompatibility between accurate EMI prediction and efficient filter circuit design. Experimental results corroborate the technique’s accuracy and reliability. This method, validated through stringent testing, holds significant practical value and broad applicability, marking a substantial advancement in the field of electromagnetic compatibility for electric drive systems. Full article

This work explores the principle of utilizing gallium nitride devices as a gate driver for silicon carbide power devices. As silicon has long reached its performance limits, Wide Bandgap semiconductors such as gallium nitride and silicon carbide have emerged as promising alternatives due to their superior characteristics. However, few publications suggest using a gallium nitride-based gate driver for silicon carbide, high-voltage power devices. Unlike standard voltage source gate drivers, this paper proposes a novel bi-polar current source resonant gate driver topology using gallium nitride transistors as a gate drive circuit for silicon carbide power switching. The driver receives a single input supply and pulsed width modulation signal, producing a high current bi-polar gate driving signal. The gate driver is validated by employing the proposed gate driver to a high-power silicon carbide transistor in a resonant boost converter. The experimental results show that the new gate driver recovers the gate charge wasted energy and provides high performances in varying high voltage loads at a 2.5 MHz switching frequency while reducing the gate losses by 26%. Full article

Permanent magnet synchronous motors (PMSMs) are widely used in a variety of fields such as aviation, aerospace, marine, and industry due to their high angular position accuracy, energy conversion efficiency, and fast response. However, driving errors caused by the non-ideal characteristics of the driver negatively affect motor control accuracy. Compensating for the errors arising from the non-ideal characteristics of the driver demonstrates substantial practical value in enhancing control accuracy, improving dynamic performance, minimizing vibration and noise, optimizing energy efficiency, and bolstering system robustness. To address this, the mechanism behind these non-ideal characteristics is analyzed based on the principles of space vector pulse width modulation (SVPWM) and its circuit structure. Tests are then conducted to examine the actual driver characteristics and verify the analysis. Building on this, a real-time compensation method is proposed, physically matched to the driver. Using the volt–second equivalence principle, an input–output voltage model of the driver is derived, with model parameters estimated from test data. The driving error is then compensated with a voltage method based on the model. The results of simulations and experiments show that the proposed method effectively mitigates the influence of the driver’s non-ideal characteristics, improving the driving and speed control accuracies by 88.07% (reducing the voltage error from 0.7345 V to 0.0879 V for a drastic command voltage with a sinusoidal amplitude of 10 V and a frequency of 50 Hz) and 53.08% (reducing the speed error from 0.0130°/s to 0.0061°/s for a lower command speed with a sinusoidal amplitude of 20° and a frequency of 0.1 Hz), respectively, in terms of the root mean square errors. This method is cost-effective, practical, and significantly enhances the control performance of PMSMs. Full article

Silicon carbide (SiC) metal-oxide semiconductor field-effect transistors (MOSFETs), as a new material, have the advantages of low drain-source resistance, high thermal conductivity, low leakage current, and high switching frequency compared with silicon (Si)-based MOSFETs. Therefore, in many industrial applications, Si MOSFETs have been replaced by SiC MOSFETs. However, as the switching speed increases exponentially, some problems are amplified, the most serious of which is the overshoot of current and voltage. The increase in voltage and current slope caused by high switching speeds inevitably leads to overshoot, oscillations, and additional losses in the circuit. This paper focusses on the actual performance of the optimised switching strategy (OSS) in circuit testing and combines the existing simulation results to verify the practicability of OSS. In this paper, the optimised switching strategy is introduced first, and then, the LTspice model of SiC MOSFET is established in detail and verifies the feasibility of the OSS through half-bridge circuit simulation. Finally, the test platform is built using a programmable gate drive module (2ASC-12A1HP). Through a 400 V/30 A double-pulse test, the practicality of the OSS is verified. The experiments show that the OSS can greatly improve the switching performance of SiC MOSFETs. Full article

Previously, we described that Adenine, Thymine, Cytosine, and Guanine nucleobases were superconductors in a quantum superposition of phases on each side of the central hydrogen bond acting as a Josephson Junction. Genomic DNA has two strands wrapped helically around one another, but during transcription, they are separated by the RNA polymerase II to form a molecular condensate called the transcription bubble. Successive steps involve the bubble translocation along the gene body. This work aims to modulate DNA as a combination of n-nonperturbative circuits quantum electrodynamics with nine Radio-Frequency Superconducting Quantum Interference Devices (SQUIDs) inside. A bus can be coupled capacitively to a single-mode microwave resonator. The cavity mode and the bus can mediate long-range, fast interaction between neighboring and distant DNA SQUID qubits. RNA polymerase II produces decoherence during transcription. This enzyme is a multifunctional biomolecular machine working like an artificially engineered device. Phosphorylation catalyzed by protein kinases constitutes the driving force. The coupling between $n$-phosphorylation pulses and any particular SQUID qubit can be obtained selectively via frequency matching. Full article

The pulse laser emission circuit plays a crucial role as the emission unit of time-of-flight (TOF) LiDAR. This paper proposes a nanosecond-level pulse laser diode array drive circuit for LiDAR, primarily aimed at addressing the issue of high-speed scanning drive for the laser diode array at the emission end of solid-state LiDAR. Based on the single pulse laser diode drive circuit, this paper innovatively designs a circuit that includes modules such as a boost circuit, linear power supply, high-speed gate driver, GaN field-effect transistor, and pulse narrowing circuit, realizing an 8-channel laser diode array drive circuit. This circuit can achieve a pulse laser array drive with a single channel operating frequency of greater than 100 kHz, an output pulse width of less than 5 ns, a peak power greater than 75 W, and a channel switching time that does not exceed 1 μs. A field programmable gate array (FPGA) is used to control the operation of this circuit and perform a series of performance tests. Experimental results show that this circuit has a high repetition rate, large output power, a narrow pulse width, and fast switching speeds, making it highly suitable for use in the optical emission module of solid-state LiDAR. Full article

PWM (pulse width modulation) is the most widely applied current conversion technology, but the high-frequency harmonics it causes have a significant negative impact on inverter system performance. This paper focuses on the three-phase T-type three-level inverter as the research object and addresses existing PWM voltage noise and midpoint potential imbalance issues by proposing an improved random SVPWM strategy, named Neutral Point Potential Balance Random Space Vector PWM (NPB–RSVPWM). The NPB–RSVPWM strategy includes three main steps: (1) introducing a midpoint potential balancing control loop to adjust the synthesis timing of the effective vectors to generate pulse signals, optimizing midpoint potential balance; (2) employing a randomly varying carrier frequency in place of the carrier used in the SVPWM strategy to generate the driving signals for switching devices; and (3) controlling the inverter through the driving pulse signals. This strategy optimizes the synthesis sequence of traditional SVPWM strategy vectors and incorporates random frequency modulation techniques. The mathematical model analyzes PWM harmonic expressions corresponding to fixed switching frequencies, and a random frequency carrier is chosen to suppress these PWM harmonics. The effective vector’s equivalent circuit is analyzed, proposing a technique for optimized vector synthesis timing. The simulation and experimental results verify that the NPB–RSVPWM technique can disperse PWM harmonic energy, reduce voltage noise, and optimize midpoint potential balance. Under the NPB–RSVPWM strategy, the line voltage spectrum becomes uniform, the maximum harmonic content is greatly reduced, and the fluctuation in the DC side midpoint potential is significantly improved. Compared with the traditional SVPWM strategy and random PWM strategy, the NPB–RSVPWM strategy has a lower voltage noise, smaller total harmonic distortion, and a more stable midpoint potential. The effectiveness and feasibility of the NPB–RSVPWM strategy are verified by simulation and experimental results. Full article

The simulation of the steady state and the non-linear stability of a load modulated power amplifier (LMPA) driven by a random modulated generator, fully performed in the frequency domain by harmonic balance (HB) techniques, is presented. The non-linear microwave circuit and the driving pseudo-random modulated (PRM) generator are integrally defined in the frequency domain. The simulation is implemented and performed using commercially available circuit simulation software. The demodulation of the output signal of the LMPA is implemented with optimally matched filters as software-defined demodulation. The simulated dynamic results of a Quasi-MMIC GaN Doherty power amplifier (DPA) are shown and compared to the measured results with a 16-QAM driving signal at 10 MS/s. The time-domain measurement allows the validation of the new simulation technique through the comparison of both the measured and the simulated error vector magnitude (EVM), the left and right adjacent channel power ratios (ACPRs) versus the average output power. This new simulation is then called pseudo-random modulated harmonic balance (PRM-HB) simulation. The full PRM-HB simulation of an LMPA driven by a random modulated signal, performed in the frequency domain at the design circuit level, results in an advanced simulation tool in the frame of the design of RF circuits and subsystems for telecommunication applications. Full article

The silicon carbide (SiC) inverter brings great advantages to the motor drive systems of new energy vehicles; however, severe challenges to the bearings also happen. The high dc bus voltage and switching frequency of SiC inverter can increase the discharge frequency and energy when the bearing grease film collapses. As a result, the bearing suffers severe electric corrosion, and the service life of the motor drive system can be shortened. In this paper, the characteristics of common-mode voltage and bearing voltage are analyzed, firstly under space vector pulse width modulation (SVPWM). After that, the common-mode equivalent circuit model of the motor drive system is established. The frequency characteristics of bearing voltage are revealed, and the safe working area is determined. Then, the frequency characteristics of bearing voltage and current are verified based on IGBT and SiC inverters in experiments. After that, by designing a common-mode filter, the bearing voltage and current are significantly attenuated. Furthermore, the active zero state PWM (AZSPWM) is adopted to reduce the common-mode voltage from the inverter. At the same time, combined with the common-mode filter, the bearing voltage and current are further reduced. The experimental results show that the switching frequency has a decisive effect on the amplitude of bearing voltage and current. The bearing voltage can be attenuated to around half of the reference bearing voltage by using the common-mode filter and AZSPWM strategy, respectively. The combination of the common-mode filter and AZSPWM strategy can reduce the bearing voltage to around one-fourth of the reference bearing voltage, which can effectively reduce the breakdown time and discharge energy of the grease oil film. Full article

A fully integrated 24-GHz radar transceiver with one transmitter (TX) and two receivers (RXs) for compact frequency modulated continuous wave (FMCW) radar applications is here presented. The FMCW synthesizer was realized using a fractional-N phase-locked loop (PLL) and programmable chirp generator, which are completely integrated in the proposed transceiver. The measured output phase noise of the synthesizer is −80 dBc/Hz at 100 kHz offset. The TX consists of a three-bit bridged t-type attenuator for gain control, a two-stage drive amplifier (DA) and a one-stage power amplifier (PA). The TX chain provides an output power of 13 dBm while achieving <0.5 dB output power variation within the range of 24 to 24.25 GHz. The RX with a direct conversion I-Q structure is composed of a two-stage low noise amplifier (LNA), I-Q generator, mixer, transimpedance amplifier (TIA), a two-stage biquad band pass filter (BPF), and a differential-to-single (DTS) amplifier. The TIA and the BPF employ a DC offset cancellation (DCOC) circuit to suppress the strong reflection signal and TX-RX leakage. The RX chain exhibits an overall gain of 100 dB. The proposed radar transceiver is fabricated using a 65 nm CMOS technology. The transceiver consumes 220 mW from a 1 V supply voltage and has 4.84 mm² die size including all pads. The prototype FMCW radar is realized with the proposed transceiver and Yagi antenna to verify the radar functionality, such as the distance and angle of targets. Full article