共查询到20条相似文献,搜索用时 156 毫秒
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展示了一种新型的基于硅IC工艺的叠层型螺旋薄膜变压器,通过分析铁氧体的特性和磁谱,设计了薄膜变压器结构和制造工艺。采用光刻技术制备形状相同且完全叠合的初级与次级线圈,提高线圈耦合效率。空心变压器两层线圈之间采用SiO2作为绝缘层;磁芯变压器的两层线圈之间采用射频磁控溅射NiZn铁氧体薄膜作为绝缘层。在10MHz~20GHz的频率范围内分别对空心和磁芯叠层型螺旋薄膜变压器进行了测试,测试结果表明:磁芯薄膜变压器的带宽和传输效率都大于空心薄膜变压器;铁氧体薄膜能大幅度提高薄膜变压器的传输效率;匝数比为10∶10的磁芯薄膜变压器传输效率在频率9.85GHz时达到78.0%的最大传输效率。 相似文献
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平面型印制电路变压器平面型印制电路变压器(Planar Printed Circuit Transformers)是种新颖的PCB产品与PCB应用的新领域。平面型印制电路变压器是种体积非常小、成本经济的高频开关变压器,由印制线路代替典型的绕制线圈,形态扁平。随着设计与加工技术的完善,电子设备小型化、轻量化需求增多,应用量会越来越多。 相似文献
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为增加PCB平面电感器单位面积上的电感值,提出一种采用磁性基板作为PCB叠层制作高感值PCB平面电感器的方法,并将磁性基板应用于两种典型的平面螺旋电感结构设计中。采用HFSS全波仿真方法对采用常规FR4基板和磁性基板的平面电感设计进行了比较,结果显示使用磁性基板能够在保持电感Q基本不变的情况下增大单位面积上的电感值,使用磁导率为2和1.5的磁性基板设计的电感器单位面积电感值能够达到13.1 n H/mm2和8.9 n H/mm2,与使用磁导率为1的FR4基板相比单位面积电感值的增大量与所使用磁性基板的磁导率基本成正比关系。 相似文献
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在室温环境下,实验采用Nd\:YAG光纤脉冲激光器辐照银(Ag)、铜(Cu)、铝(Al)三种光滑连续的金属薄膜,制备出了对应的三种金属纳米颗粒薄膜。通过调节激光扫描速率可以实现三种金属纳米颗粒薄膜的局域表面等离子体共振(LSPR)波长和强度的调谐。其中,Ag纳米颗粒薄膜在可见光波段的等离子体吸收峰的波长和强度均表现出较宽的调谐范围,Cu纳米颗粒薄膜在可见光波段的等离子体吸收峰的波长和强度均表现较小的调谐范围,Al纳米颗粒薄膜在紫外光波段的等离子体吸收峰窄而尖锐,且LSPR波长调谐范围也较小。与激光辐照前的三种金属薄膜相比,激光辐照后生成的三种金属纳米颗粒薄膜出现了更强的表面增强拉曼散射信号。有限差分时域仿真模拟出的样品的电场强度分布与实验得到的表面增强拉曼散射结果一致。 相似文献
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Very small manually wound transformers for sub-watt DC-DC converters are notorious for their relatively high cost and low reliability. In this paper, an isolated low-profile low-power 8 MHz soft-switching power converter using a coreless printed circuit board (PCB) transformer is described. Coreless PCB transformers eliminate several problems of their core-based counterparts in low-power applications. The diameter of the coreless PCB transformer is merely 0.46 cm. The converter's power output is about 0.5 W with a typical transformer efficiency of 63%. The high-frequency capability, high reliability and the low-profile structure make coreless PCB transformers a viable and attractive option for reliable mega-hertz switching converters and micro-circuits 相似文献
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The authors report the use of a coreless printed circuit board transformer for power conversion with very high power density and efficiency. A coreless PCB transformer with an outermost radius of /spl sim/1 cm and 19 turns for both the primary and secondary windings can transfer 19 W at an efficiency of 90%, resulting in a record power density of 24 W/cm/sup 2/. The power density and energy efficiency of a coreless PCB transformer are higher than those of core-based microtransformers. Coreless transformers are simpler in structure, easier to implement in silicon wafer and cheaper than core-based planar transformers. 相似文献
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Some electromagnetic aspects of coreless PCB transformers 总被引:2,自引:0,他引:2
In this paper, some EMI aspects of using coreless PCB transformers are addressed. Based on the antennas theory, the radiated power of a coreless PCB transformer is estimated and found to be negligible. The electromagnetic field plot of a power electronic circuit using a gate drive circuit isolated by a coreless PCB transformer has been recorded. The major radiated EMI source in the frequency range of 30 MHz to 300 MHz is found to be the copper tracks of the power circuit, where switching transients occur, rather than the coreless PCB transformer. Coreless PCB transformers essentially operate at relatively low frequency (8 MHz in this case) by near-field magnetic coupling. Experimental results have confirmed that the application of coreless PCB transformer in gate drive circuit will not impose any serious EMI problem on the power electronic circuit 相似文献
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Gate drive circuits for modern power electronic switches, such as MOSFET and insulated gate bipolar transistor (IGBT), often require electrical isolation. This paper describes the modeling and experimental results of some coreless printed circuit board (PCB)-based transformers that can be used for MOSFET and IGBT devices at high-frequency (500 kHz to 2 MHz) operation. PCB-based transformers do not require the manual winding procedure and thus simplify the manufacturing process of transformer-isolated gate drive circuits. With no core loss, coreless transformers are found to have favorable characteristics at high-frequency operations. This project demonstrates an important point that the size of the magnetic core can approach zero and become zero when the frequency is sufficiently high 相似文献
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Magnetic cores have been used in transformers for over a century. In this paper, the authors present a fundamental concept of using “coreless” printed-circuit-board (PCB) transformers. With the aid of a high-frequency equivalent circuit, the use and basic characteristics of coreless PCB transformers are described. Optimal operating conditions for minimum input power requirement and maximum efficiency operations are identified. Coreless PCB transformers have the advantages of low costs, very high power density, no limitation due to magnetic cores, no magnetic loss and ease of manufacturing. They have the potential to be developed in microcircuits. A printed planar PCB transformer with a diameter of about 1.0 cm and power capability of 19 W has been successfully tested. The power density of the PCB transformer demonstrated in this paper is 24 W/cm2. The maximum efficiency can be greater than 90%. The analysis has been confirmed with experiments. Coreless printed transformers have great potential in applications in which stringent height and space requirements have to be met 相似文献
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Gate drive circuits for power MOSFETs and insulated gate bipolar transistors (IGBTs) often require electrical isolation. Coreless printed circuit board (PCB) transformers have been shown to have desirable characteristics from a few hundreds of hertz to a few megahertz and can be used for both power and signal transfer at low-power level. At low operating frequency, the magnetizing inductance has such low impedance that the driving power requirement could become excessive. This paper describes the use of a coreless PCB transformer for isolated gate drive circuits over a wide-frequency range. Based on a resonance concept, the optimal operating condition that minimizes the power consumption of the gate drive circuits is developed and verified with experiments. The coreless PCB transformer demonstrated here confirms a fundamental concept that the size and volume of a magnetic core could approach zero and become zero if the operating frequency is sufficiently high. Coreless PCB transformers do not require the manual winding procedure and thus simplify the manufacturing process of transformer-isolated gate drive circuits and low-power converters. Their sizes can be much smaller than those of typical core-based pulse transformers. The electrical isolation of a PCB is much higher than that of an optocoupler 相似文献
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This paper describes the modeling and implementation of a coreless printed circuit board (PCB)-based transformer with “multiple” secondary outputs. This new PCB transformer has been successfully applied in complementary gate drive circuits in a novel low-profile power converter with high-power density and a converter bridge. The PCB-based transformers do not require the manual winding procedure and thus simplify the manufacturing process of transformer-isolated gate drive circuits. The use of the multiple secondary outputs can in principle simplify the complementary gate drive circuits that are often required in many power electronics applications 相似文献
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Galvanic isolations are essential in many electrical patient-monitoring devices and industrial applications. In this paper, a low-profile wideband three-port isolation amplifier using coreless printed-circuit-board (PCB) transformers for isolation is studied. The PCB thickness used in the isolation amplifier is 0.4 mm. The diameters of the two coreless PCB transformers are 9.75 and 5.856 mm, respectively. Operating conditions of the transformers and a design guideline of the isolation amplifier are detailed in this paper. Experimental results show that the isolation amplifier under investigation can transmit an analog signal from 20 mHz to 1.1 MHz with good linearity. Comparison of the prototype with an industrial isolation amplifier is also included 相似文献