A generalized quantum resonant converter using a new quantumresonant module

For the generalization of quantum resonant converters, new quantum resonant modules, which are a quantum series resonant module (QSRM) and a quantum parallel resonant module (QPRM), are proposed. The QSRM and QPRM are modeled as an equivalent inductor and an equivalent capacitor, respectively. The models of the proposed modules are useful in deriving the practical family of quantum resonant converters corresponding to the conventional PWM converters. The AC/AC quantum resonant converters are useful in high-performance applications. The concept of modules and the validity of the modeling are confirmed by the experiment     

基于粒子群算法的LCLC谐振变换器优化设计

LCLC谐振变换器广泛应用在空间行波管放大器(TWTA)中,起到升压的作用。在LCLC谐振变换器中,具有多个谐振参数,即变压器漏感、串联谐振电容、励磁电感以及并联谐振电容。多个谐振参数增加了LCLC谐振变换器总损耗优化的难度。该文提出一种基于粒子群优化算法的LCLC谐振变换器优化设计方法,解决LCLC谐振变换器由于多个谐振参数造成的总损耗优化困难的问题。首先,推导了LCLC谐振变换器的总损耗公式;其次,采用粒子群优化算法,对LCLC谐振变换器的总损耗进行了优化,得到了总损耗最小时的谐振变换器参数;最后,基于优化的LCLC谐振变换器参数,搭建了LCLC谐振变换器,并进行了一系列实验。实验结果证明了该优化设计方法的有效性。     

W 波段回旋管谐振腔特性参数测量方法的研究*

W 波段回旋振荡管是一种重要的高功率毫米波源,它通常采用圆柱开放式谐振腔作为其高频结构。 谐振腔所具有的特性参数,如谐振频率和品质因数影响了整管的性能。在W 波段,特性参数对于尺寸的变化特别敏 感,因此,有必要对加工好的开放式谐振腔的特性参数进行测量。利用直接耦合法实现了对5 组开放式谐振腔谐振 频率和品质因数的无损检测,实验结果验证了该方法的可行性与有效性。同时,分析了加工误差对谐振腔性能造成 的影响,结果表明,当开放式谐振腔渐变角度的加工误差达到7%以上时,谐振频率将偏移0.2GHz。     

Design considerations for three element L-LC resonant inverters for induction heating

This article presents the up-to-date conclusions concerning the design of the three element L-LC resonant inverters for induction heating applications. The main properties of the L-LC resonant tank are presented. The advantages of the L-LC circuit over the series resonant inverter (SRI) are explained: namely, its current gain and short-circuit robustness. Finally, a transformation algorithm is proposed which allows substitution of the SRI by an equivalent L-LC circuit, that is to say, an LLC which achieves the same output power at the same resonant frequency with the same heating coil and piece.     

Ultrafast solid-state mode-locked lasers using resonantnonlinearities

The authors discuss recent experiments in which resonant nonlinearities are used in order to directly mode lock solid-state lasers or to initiate self-focusing mode locking. Three configurations using resonant nonlinearities are considered. They are coupled cavity mode locking using a semiconductor nonlinear mirror, a further extension of this including self-focusing mode locking, and the closely related case of an intracavity saturable absorber dye. In the last two cases, the resonant nonlinearity only starts the self-focusing mode locking. Passive mode-locking techniques using resonant nonlinearities have the advantage that they self-start mode locking. The focus is on the Ti:sapphire laser, for which the techniques were first demonstrated     

A new method to regulate resonant converters

A resonant frequency-modulation method is presented as an alternative to the switching frequency-modulation method to regulate resonant converters. A switch-controlled inductor and switch-controlled capacitor, in which switching losses are found to be very low due to zero-current or zero-voltage switching, are developed to do so. A new family of resonant converters that are regulated at a fixed switching frequency is proposed. A steady-state analysis of the Class E resonant converter regulated by a switch-controlled capacitor is presented. Theoretical and experimental results verify the validity of the proposed method. The efficiency measured from a breadboard of 1 MHz, 5 V, 25 W Class E regulated resonant DC-DC converter is up to 83%     

Self-sustained oscillating resonant converters operating above theresonant frequency

This paper presents a new control technique for resonant converters. Unlike conventional variable frequency control which externally imposes the switching frequency, the proposed scheme is based on controlling the displacement angle between one of the resonant circuit variables, typically the current through the resonant inductor, and the voltage at the output of the inverter. As a result, zero-voltage switching (ZVS) can be ensured over a wide operating range. The proposed control technique cam be applied for series, parallel, and series-parallel resonant converters. As an example, the static characteristics and dynamic model of a series-parallel resonant converter with the proposed controller are derived and the system behaviour is investigated in detail. Experimental results are given to demonstrate the operation of resonant converters with the proposed controller and to validate the analysis     

Freestanding GaN Resonant Gratings at Telecommunication Range

We theoretically and experimentally demonstrate a freestanding gallium nitride (GaN) resonant grating at telecommunication range. The optical responses of the freestanding GaN resonant gratings are analyzed by the rigorous coupled-wave analysis method. The freestanding GaN resonant gratings are validated on 850-nm freestanding membrane by a combination of electron beam lithography, fast atom beam, etching, and deep reactive ion etching. The polarization properties of such freestanding GaN resonant gratings are demonstrated in reflectance measurements, and the experimental results correspond well to the theoretical model. The strong resonant peaks show a clear dependence on the duty ratio under transverse magnetic polarization, and a promising resonant peak of the fabricated freestanding GaN resonant grating, in which the grating period $P$ is 1500 nm, the grating height $h$ is 230 nm, and the grating width is 280 nm, is observed at 1516.4 nm with a full-width at half-maximum of 4 nm.      

A capacitively loaded half-wavelength tapped-stub resonator

This paper examines a new resonator which is created by adding capacitive loading to a half-wavelength tapped-stub resonator. This capacitively loaded resonator has the property that both the Q and the resonant frequency can be set independently. This property is important because it allows this resonator to be used as either a tracking filter which maintains a constant bandwidth or as a filter which can vary its Q while maintaining a fixed resonant frequency. In this paper, equations are derived for choosing capacitance values that yield a desired resonant frequency and value of Q. Examples of using this resonator as both a fixed-frequency variable-Q filter and a constant-bandwidth tracking filter are provided. Theoretical results are verified by measurements     

Design and Application for PV Generation System Using a Soft-Switching Boost Converter With SARC

In order to improve the efficiency of energy conversion for a photovoltaic (PV) system, a soft-switching boost converter using a simple auxiliary resonant circuit, which is composed of an auxiliary switch, a diode, a resonant inductor, and a resonant capacitor, is adopted in this paper. The conventional boost converter decreases the efficiency because of hard switching, which generates losses when the switches are turned on/off. During this interval, all switches in the adopted circuit perform zero-current switching by the resonant inductor at turn-on, and zero-voltage switching by the resonant capacitor at turn-off. This switching pattern can reduce the switching losses, voltage and current stress of the switching device. Moreover, it is very easy to control. In this paper, we have analyzed the operational principles of the adopted soft-switching boost converter, and it is designed for PV generation system. Simulation and experimental results are presented to confirm the theoretical analysis.      

High-Frequency Resonant Transistor DC-DC Converters

Transistor dc-dc converters which employ a resonant circuit are described. A resonant circuit is driven with square waves of current or voltage, and by adjusting the frequency around the resonant point, the voltage on the resonant components can be adjusted to any practical voltage level. By rectifying the voltage across the resonant elements, a dc voltage is obtained which can be either higher or lower than the input dc voltage to the converter. Thus, the converter can operate in either the step-up or step-down mode. In addition, the switching losses in the inverter devices and rectifiers are extremely low due to the sine waves that occur from the use of a resonant circuit (as opposed to square waves in a conventional converter); also, easier EMI filtering should result. In the voltage input version, the converter is able to use the parasitic diode associated with an FET or monolithic Darlington, while in the current input version, the converter needs the inverse blocking capability which can be obtained with an IGT or GTO device. A low-power breadboard operating at 200-300 kHz has been built. Two typical application areas are switching power supplies and battery chargers. The converter circuits offer improvements over conventional circuits due to their high efficiency (low switching losses), small reactive components (high-frequency operation), and their step-up/stepdown ability.     

Optical-fiber resonant rings based on polarization-dependentcouplers

A theoretical and experimental analysis has been carried out on optical-fiber resonant rings based on polarization-dependent couplers. The analysis includes the use of optical-fiber polarization splitters and polarization-preserving fiber as particular cases. Two resonant configurations are presented and their sensor applications discussed. The changes of polarizations that take place in the ring are used as an effective distributed coupling which in one configuration feeds power into a resonance, and in the other introduces a variable attenuation, changing the effective losses of the resonant mode. The experimental characteristics of the system enable detection of small polarization changes. The experimental characteristics of a resonant ring about 2.5-m long and a polarization-selecting coupler are presented     

Hybrid resonant inverter-based induction heating converter with CFPDM

This article proposes a 50?kHz hybrid (series–parallel) resonant inverter-based induction heating (IH) converter which is controlled with commercial frequency pulse density modulation (CFPDM). Since the hybrid resonant inverter enhances the series resonant inverter performance due to short-circuit handling capability and current gain, it has been successfully employed in IH. High power conversion efficiency and wide output power range can be obtained using CFPDM. In addition, some harmonic current problems occurred in conventional pulse density modulation because of the resonant frequency of non-smoothing filter are eliminated via CFPDM. There is no need for the application of any additional switches or passive components in CFPDM. In this article, CFPDM hybrid resonant inverter-based IH converter is modelled and the analysis of the converter is presented in detail. The operation principle of CFPDM controller is shown. In addition, the advantages of hybrid resonant inverter and CFPDM are stated. The theoretical analysis is verified via simulation and experimental studies, which are in very good agreement.     

A kind of magnetron cavity used in rubidium atomic frequency standards

Research on the magnetron cavity used in the rubidium atomic frequency standards is developed, through which the main characteristic parameters of the magnetron cavity are studied,mainly including the resonant frequency,quality factor and oscillation mode.The resonant frequency and quality factor of the magnetron cavity were calculated,and the test results of the resonant frequency agreed well with the calculation theory.The test results also show that the resonant frequency of the magnetron cavity can be attenuated to 6.835 GHz,which is the resonant frequency of the rubidium atoms,and the Q-factor can be attenuated to 500-1000.The oscillation mode is a typical TE₀₁₁ mode and is the correct mode needed for the rubidium atomic frequency standard.Therefore these derivative magnetron cavities meet the requirements of the rubidium atomic frequency standards well.     

共振隧穿电路中翻转-传输代数系统的建立

在传统数字电路天关一信号理论的基础上.提出了一个全新的基于共振隧穿RT(Resonant Tunneling)电路的翻转-传输理论,建立了适用于共振隧穿电路的翻转-传输代数系统,确定了两种联结运算,并用共振隧穿器件实现了该两种联结运算的基本电路结构.为设计共振隧穿电路特别是基本逻辑电路提供了一个全新的理论基础和系统的设计方法.     

A nonlinear resonant switch

A resonant switch is introduced that uses linear tank elements. Zero-current switching is obtained even through the peak transistor voltage and current stresses can approach those of an equivalent ideal pulsewidth-modulated converter. Reduced switching loss without a substantial increase in conduction loss is therefore possible. An approximate analysis is outlined, and transistor peak-voltage and current stresses are shown to be much lower than those of linear resonant switch technologies. Single-transistor implementations of the buck, boost, and buck-boost nonlinear resonant switch converters are given. Results are presented which experimentally prove the validity of the nonlinear resonant switch concept, as well as that of the approximate analysis     

Dielectric slab-loaded resonant cavity for applications requiringenhanced field uniformity

This paper introduces and analyzes a rectangular resonant structure that provides an alternative to the multimode resonant cavity in applications requiring enhanced field uniformity. The resonant cavity contains four dielectric loading slabs placed along the cavity walls. Its first resonant mode is related to the uniform field distribution supported in a rectangular TEM waveguide. The electromagnetic fields within the cavity are described using a closed-form approach, with approximations taken to account for the presence of two of the loading slabs. Application of the boundary conditions leads to an eigenvalue formulation, which is used to determine resonant frequencies and electromagnetic field distributions within the cavity. Measurements of both resonant frequencies and electric field magnitudes confirm the analysis. This work provides the basis for future analyses and implementation of slab-loaded cavities in both scientific and industrial settings     

A discussion on the properties of electrically small self-resonant wire antennas

The performance properties of several electrically small, self-resonant wire antennas are compared as a function of their total wire length, geometry, and effective volume. The radiation properties considered include resonant frequency, radiation resistance, and quality factor (Q). It is shown that the resonant properties of these antennas are directly a function of the antenna's effective height and effective volume, which are established by both total wire length and geometry. When the total wire length and geometry of these antennas are configured such that the antennas exhibit the same effective height and volume, their resonant properties are essentially identical, independent of any differences in their total wire length and geometry. Both computed and measured data are presented to support the comparison of the antennas' resonant properties.     

A new phase-controlled parallel resonant converter

A phase-controlled resonant converter was obtained by connecting in parallel the AC loads of two identical parallel resonant inverters. A phase shift between the drive signals of the two inverters controls the amplitude of the output voltage of the new inverter. A voltage-driven rectifier is used as an AC load of the inverter, which results in a phase-controlled parallel resonant DC-DC converter. A frequency-domain analysis is performed for the steady-state operation of the inverter, and two types of voltage-driven rectifiers and design equations are derived. The converter can be operated at a constant switching frequency, which reduces EMI problems. It is found that for switching frequencies higher than the resonant frequency by a factor of 1.07, the load of each switching leg is inductive. The converter is capable of regulating the output voltage in the range of load resistance from full-load to no-load. Experimental results are presented for a prototype of the phase-controlled parallel resonant converter with a center-taped rectifier tested at an output power of 50 W and a switching frequency of 116 kHz     

单个长周期光纤光栅实现横向负载和温度的同时测量

发现高频CO2 激光脉冲写入的长周期光纤光栅 (LPFG)的谐振波长的横向负载灵敏度具有很强的方向相关性 ,且在两个特定的负载方向上谐振波长对横向负载不敏感 ,而谐振峰幅值与不同方向的横向负载都有很好的线性关系。这种LPFG的谐振波长随温度变化而线性漂移 ,使谐振峰幅值对温度变化不敏感 ,由此提出了用单个LPFG的谐振波长和谐振峰幅值两个参量分别实现对温度和横向负载进行同时独立绝对测量的传感器设计方案 ,可望从根本上解决LPFG在测量中存在的温度和横向负载之间的交叉敏感问题