Phase-shift Control Research Articles

Programmable beam steering and quasi-continuous phase shift on a 2-bit terahertz coding metasurface with HEMT-switched multimodal modulation.

Terahertz reconfigurable intelligent surfaces (RIS) stand out from conventional phased arrays thanks to their unique electromagnetic properties and intelligent interconnect paradigms. They are a vital technology for terahertz wireless communication and radar detection systems. Compared with 1-bit coding metasurfaces, 2-bit coding metasurfaces offer significant advantages such as single beam steering and reduced quantization errors. Electrically controlled switchable coding metasurfaces have been restricted by the switch performance and integration technology, limiting reported devices to 1-bit coding. Additionally, metasurfaces that offer quasi-continuous phase modulation across a 2π range have garnered extensive attention for their higher phase shift precision and regulation freedom. This paper proposes a 2-bit multimodal THz quasi-continuous phase shift coding metasurface based on asymmetrically configured high electron mobility transistor (HEMT)-dipoles. The meta-device consists of two asymmetrically combined HEMT-dipole resonant structures, wherein the versatile density variations of two-dimensional electron gas (2DEG) introduce subtly local-field modulation under different external voltage combinations, rendering the quasi-continuous phase shift of 0° to 350° at 0.376 THz with a minimum incremental step of 6°. Moreover, selecting optimal 2-bit coding states within the quasi-continuous phase shift loop constructed different array phase gradients based on Snell's law, enabling real-time beam steering from 21° to 48° within the 0.365-0.385 THz frequency range. The simulation results align closely with the experimental findings, marking the first achievement of real-time programmable phase shift control and 2-bit beam steering using electrically controlled switches in the terahertz domain. This research provides a practical approach for real-time quasi-optical continuous phase modulation control and programmable single-beam electronic steering, with promising applications in terahertz wireless communication, radar detecting, and computational imaging, among other fields.

Asymmetric Phase Shift Control in Multiphase Dual Active Bridge DC/DC Converters

Asymmetric Phase Shift Control in Multiphase Dual Active Bridge DC/DC Converters

A novel noncommunication‐based inductive power transfer control technique for battery charging application

AbstractIn order to realize the precise control of the output voltage and current of the inductive power transfer (IPT) battery charging system, wireless communication‐based control are generally employed in a lot of existing works. However, the stability of the IPT converter will be impaired if communication fails. This paper proposes a novel noncommunication‐based control strategy with a simple switched controlled capacitor design at the receiver side of the IPT system. A series‐inductor–capacitor–capacitor compensation network is selected to verify the proposed control strategy. Without feedback wireless communication, the proposed IPT system can realize reliable constant current and constant voltage output control over full load range at a fixed switching frequency. At the receiver side, switched controlled capacitor is introduced to control reactive current and convey the output‐side information to the transmitter side in the form of impedance angle. At the transmitter side, impedance angle is detected in real time, and phase shift control is introduced to regulate the output voltage or current of the system. Detailed analysis, implementation, hardware realization of the proposed noncommunication‐based control is presented in this paper. A 250 W experimental prototype is built in the laboratory to verify the proposed control strategy. Constant voltage and constant current for battery charging application are realized through noncommunication‐based control. Zero voltage switching over full range of load and minimized reactive current are achieved, which allows high efficiency operation. Compared with existing work in the literature, the proposed noncommunication‐based control provides the benefits of reduced hardware cost, higher system reliability and stability.

Design of a Magnetically Coupled Resonant Implantable Medical Device Wireless Power Transmission System

This paper systematically describes the design and optimisation strategy of wireless charging technology for implantable medical devices. Starting from the theoretical basis of magnetically coupled resonant wireless power transmission (MCR-WPT), an efficient transmission circuit is designed and the resonant circuit characteristics are analysed. Meanwhile, the effects of the outer diameter, the number of turns of the transmitting coil and the turns spacing on the magnetic flux density and the AC internal resistance are obtained through the principle analysis. The coil parameters are adjusted through simulation experiments to improve the transmission efficiency. Then, the safety and stability of the device are ensured by temperature-power double closed-loop control. Then the closed-loop phase-shift control strategy is introduced to ensure that the system can output power stably in complex environments. In this paper, a low-power, safe and high-efficiency wireless energy transmission system is built, which provides a comprehensive and in-depth technical reference for the development of wireless power supply technology for implantable medical devices.

Wide-range ZVS control technology of bidirectional dual-bridge series resonant DC/DC converters based on phase-shift frequency modulation control

Abstract Increasing the switching frequency helps optimize the performance of resonant DC-DC converters and reduces the size of resonant components, but it also increases the switching losses. To address the challenge of achieving soft switching in the medium to low power range, this paper proposes a new control strategy. In this paper, it achieves a wide range of Zero Voltage Switching (ZVS). It combines Variable Frequency Modulation (VFM) and Phase Shift Modulation (PSM), utilizing Minimum Current Trajectory (MCT) control to reduce the system’s conduction losses. Besides, VFM is used to extend the ZVS range and reduce switching losses.

A New Proposed Triple Active Bridge Converter for Fuel Cell Applications

This paper deals with a new proposed three port converter structure dedicated for two-input source hybrid systems especially for fuel cell applications. This converter is made up of three-phase triple active bridges which are galvanically isolated by means of three single phase high frequency transformers. The present converter integrates a fuel cell as the primary power source with a battery that stores energy, harnessing the unique benefits of both sources to deliver reliable power to a DC load through a single power conversion stage. In order to control the power flow between the ports, a phase shift control technique has been carried out to generate the control signals of the load and battery side bridges in reference with those of the fuel cell bridge. A detailed analysis of the proposed converter has been presented in this paper. A novel proposed energy management algorithm has been developed. This algorithm provides a robust solution for managing and distributing power flow between the converter's ports, ensuring an optimal balance of power delivery. The algorithm has been rigorously validated through simulations and experimental test, using Dspace 1104 board.

Implementation of Single-Phase Shift (SPS) and Extended Phase Shift (EPS) for Dual Active Bridge (DAB)

Objectives: To improve power transfer and efficiency in Dual Active Bridge (DAB) converters, this study compares and assesses the Single-Phase Shift (SPS) and Extended Phase Shift (EPS) control techniques. Methods: Using the Dual Active Bridge (DAB) arrangement, the research focuses on implementing SPS and EPS control methods to an Isolated Bidirectional Full-Bridge DC-DC Converter (IBDC). A comprehensive review of the IBDC's operating modes and the EPS's control concept is included in this study. Findings: In comparison with EPS, SPS control is limited by a smaller operating range, higher power loss, and higher circulating current. Conversely, EPS exhibits benefits such as decreased back power flow, increased Zero Voltage Switching (ZVS) range, and decreased current stress. These conclusions are supported by the simulation results, which show that EPS control outperforms SPS in terms of operational stability, harmonics, and efficiency. Under the SPS control at different phase shift minimums, THD is 15.06%; whereas, for EPS it is 12.90%. Novelty: This study demonstrates how EPS outperforms SPS in DAB converters, providing better operational range, THD, and efficiency. Keywords: Isolated Bidirectional Full-Bridge DC–DC Converters (IBDCs), Dual Active bridge (DAB), Single Phase Shift (SPS), Extended Phase Shift (EPS), Current Stress, Power Transmission

Hybrid Control Strategy for LLC Converter Based on Improved Fruit Fly Optimization Algorithm

This paper presents a hybrid control strategy for the LLC resonant converter in X-ray machines, addressing the limitations of voltage gain range under Pulse Frequency Modulation (PFM) and dynamic response under Phase Shift Modulation (PSM). The strategy employs an improved fruit fly optimization algorithm (IFOA) to optimize PI control and integrate Hybrid Phase-Shifted and Frequency-Modulated control. It dynamically adjusts the switching frequency and phase shift angle to maintain output stability and efficiency, ensuring optimal operation under rated conditions. A Matlab-based system simulation model confirmed the stability and accuracy of the IFOA in controlling the converter. Subsequent prototype testing validated the strategy’s effectiveness in reducing conduction losses, enhancing overall efficiency, and demonstrating practical feasibility and superiority.

Optimizing resource allocation for enhanced urban connectivity in LEO-UAV-RIS networks

Sixth-generation (6G) communication advancements target massive connectivity, ultra-reliable low-latency communication (URLLC), and high data rates, essential for IoT applications. Yet, in natural disasters, particularly in dense urban areas, 6G quality of service (QoS) can falter when terrestrial networks—such as base stations—become unavailable, unstable, or strained by high user density and dynamic environments. Additionally, high-rise buildings in smart cities contribute to signal blockages. To ensure reliable, high-quality connectivity, integrating low-Earth Orbit (LEO) satellites, unmanned aerial vehicles (UAVs), and reconfigurable intelligent surfaces (RIS) into a multilayer (ML) network offers a solution: LEO satellites provide broad coverage, UAVs reduce congestion with flexible positioning, and RIS enhances signal quality. Despite these benefits, this integration brings challenges in resource allocation, requiring path loss models that account for both line-of-sight (LOS) and non-line-of-sight (NLOS) links. To address these, a joint optimization problem is formulated focusing on resource distribution fairness. Given its complexity, a framework is proposed to decouple the problem into subproblems using the block coordinate descent (BCD) method. These subproblems include UAV placement optimization, user association, subcarrier allocation via orthogonal frequency division multiple access (OFDMA), power allocation, and RIS phase shift control. OFDMA efficiently manages shared resources and mitigates interference. This iterative approach optimizes each subproblem, ensuring convergence to a locally optimal solution. Additionally, we propose a low-complexity solution for RIS phase shift control, proving its feasibility and efficiency mathematically. The numerical results demonstrate that the proposed scheme achieves up to 43.5% higher sum rates and 80% lower outage probabilities compared to the schemes without RIS. The low complexity solution for RIS optimization achieves performance within 1.8% of the SDP approach in terms of the sum rate. This model significantly improves network performance and reliability, achieving a 16.3% higher sum rate and a 44.4% reduction in outage probability compared to joint optimization of SAT-UAV resources. These findings highlight the robustness and efficiency of the ML network model, making it ideal for next-generation communication systems in high-density urban environments.

Algorithm for receiving signal source tracking using signal phase perturbations in symmetrical antenna arrays

Formulation of the problem. In radio engineering systems, search and tracking the angular position of the source of the received signal in the most known cases are carried out using the monopulse antenna devices. However, such devices require the usage of a several directional antennas and a complex sum-difference devices to combine the output signals of these antennas. If an Antenna Array (AA) is used as a directional antenna, then the AA calibration algorithms can be also used for this tracking. However, such the algorithms are slow, because they require a large number of the array output power measurements, which are proportional to the number of its antennas. Target. To present a simple algorithm for searching the angular position of a signal source using the rectangular arrays. Results. The operation of the proposed algorithm is based on the symmetrical perturbations (changes) of all the signal phases in the AA channels by the fixed values relative to their current values and is based on the estimations the values of the signals at the AR output after these perturbations. In a two-dimensional AA it is necessary to perform four such the perturbations, and in a linear AR it is necessary to perform the two ones. To increase the accuracy of the algorithm, it is proposed to use a correlator or a matched filter to estimate the output signals of the AA if these signals are the pseudorandom sequences. The paper presents the mathematical details of the proposed algorithm and the simulation results which demonstrate its efficiency. Practical significance. The presented algorithm can be used to track the changes in the position of a signal source caused by the movement of this source or the movement of the AA itself. The algorithm can be implemented in the analog phased arrays containing controlled phase shifters in their channels or in the arrays with the digital beamforming, in which the phase perturbations can be implemented by the changing of the complex-valued weights. The usage of a correlator or a matched filter at the AP output allows the proposed algorithm to be used when receiving the signals under the conditions of the low signal-to-noise ratio.

An integrated hybrid dual-frequency wireless charging system with anti-offset performance via phase-shift control for consumer electronics

Abstract Wireless charging systems for consumer electronics suffer from the offset issue, which leads to drastic changes in the mutual inductance and thus produces unstable outputs. To solve the issue, this paper proposes an integrated hybrid dual-frequency wireless charging system with an anti-offset performance. The proposed topology can be equivalent to the CLC-S and S-S topologies at fundamental and third harmonic frequencies, respectively. Combining the opposite trends of the output voltages in the CLC-S and S-S topologies, the anti-offset performance can be realized. To further enhance the anti-offset performance, the phase-shift control is adopted to adjust the ratio of fundamental and third harmonic, thus extending the anti-offset range. The mathematical and experimental models are established. The experimental results are well aligned with the calculated ones, confirming that the proposed system can maintain stable output and high efficiency under different offsets.

Analysis of Phase-Shift Control Method for Efficiency Optimization of Multi-Coil Wireless Power Transfer

Analysis of Phase-Shift Control Method for Efficiency Optimization of Multi-Coil Wireless Power Transfer

Enhanced Hybrid Power Grid System Using Adaptive Fuzzy Logic Controller by Supraharmonics Reduction

Hybrid Systems meet the growing needs of electrical energy in the countries. The mismatching of hybrid systems leads to the phase shift in the three-phase signals, producing more harmonics in the band of 2 to 150kHz.However, due to various factors, harmonics have arisen from the RITHAPF and TCR which act as the phase shift controller in hybrid systems. Therefore, the Adaptive Fuzzy controller is employed with RITHAPF and TCR to maintain the phase shift and attenuate the harmonics produced. which outperforms the Hysteresis controller by 17.5% approx. in harmonic suppression and the simulation carried out for various phase angles.

Extended Phase Shift Control of a Novel Bidirectional DC–DC Converter With Direct Power Transfer

Extended Phase Shift Control of a Novel Bidirectional DC–DC Converter With Direct Power Transfer

Optically Controlled Fine-Tuning Phase Shift Cell Based on Thin-Film Ge2Sb2Te5 for Light Beam Phase Modulation

We present the experimental study of free-space optical control of the optical beam phase shift caused by the formation of a layered structure in an elementary controllable cell made of phase-change material Ge2Sb2Te5 subjected to the controlling effect of pulsed laser radiation. The phase change of the signal optical beam passing through the controlled cell from phase-change material relative to the control beam in the Jamin interferometer is demonstrated.

A composite control method of PWM and phase shift for a three-level DC-DC converter

Abstract This research introduces a control strategy for the Three Level Active Half Bridge (TL-DAHB) DC-DC converter that integrates PWM combined with phase-shift control. This composite control method precisely regulates the output voltage by adjusting the phase-shift duty cycle between the input and output sides. Additionally, the application of the PWM control loop optimizes the duty cycle of the switches, effectively reducing the current stress on the converter during operation, improving transmission efficiency, and decreasing conduction losses of the switches. These enhancements boost the overall performance and the reliability of the converter. With its excellent voltage regulation capabilities and safety features, this converter is an ideal choice in the field of power conversion, especially in applications that demand high levels of stability and safety.

Transformer-Based RIS Phase Shift Control for Ultra-Low Latency V2X Systems

Transformer-Based RIS Phase Shift Control for Ultra-Low Latency V2X Systems

Fractional order PID controlled phase shift modulated interleaved Watkins–Johnson converter-based LED driver with reduced current ripple

Fractional order PID controlled phase shift modulated interleaved Watkins–Johnson converter-based LED driver with reduced current ripple

Load voltage study of LCC-S type wireless energy transmission system based on phase shift control

Abstract When the light load is applied in an LCC-S type wireless power transmission (WPT) system, the system does not have constant voltage characteristics, which affects the normal use of power equipment. If a DC/DC converter is used to regulate the voltage at both ends of the load to keep it constant, it will increase the size and cost of the system, and the efficiency is also reduced. For this reason, in this paper, phase-shift control is carried out based on the LCC-S type WPT system, and the LCC-S resonant compensation network is first modeled and analyzed in terms of its working principle. Then, the principle of phase-shift control is analyzed, the relationship between the drive signal phase-shift angle and the load voltage in the phase-shift control is deduced, and finally, a simulation model is built in Matlab/Simulink to verify the correctness of the control strategy.

Modified EPS Control and Topology Modification for Two-Stage Bidirectional AC-DC Converter for V2G Applications

Abstract For the two-stage bidirectional AC-DC converter applied to vehicle-to-grid (V2G), this paper studies the modulation strategy and the topology of the dual active bridge (DAB) converter in the DC-DC stage. Aiming at the problem of large circulating current due to the fixed internal phase shift under the traditional extended phase shift (EPS) control, this paper modified the EPS modulation strategy by deciding whether the internal phase shift is generated by the primary or secondary side based on the voltage gain, which realizes the high-efficiency power transfer under wide voltage gain. To realize the full load range zero voltage switching (ZVS) with junction capacitors taken into account, it is proposed to parallel an additional auxiliary inductor between the bridge arms of the DAB converter, and the operating mechanism and the improved effect are analyzed in detail. Finally, a simulation circuit was built using PSIM software to verify the correctness.