共查询到18条相似文献,搜索用时 109 毫秒
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用ANSYS软件对暴露在空气中共面型GaAs光导开关进行了模拟仿真,根据其电场分布在X方向和Y方向的剖面图可以看出:在GaAs表面、电极、空气隙3种介质的交界面是极易发生击穿的区域,特别在电极的拐角部位。对用空气和Si3N4介质包覆开关表面时的电流分布进行了模拟比较,给出了X方向剖面图,结果表明:经Si3Ni4薄膜保护的GaAs光导开关的耐压能力可提高2个数量级。对设计制作的3mm间隙共面型GaAs光导开关进行了耐压试验研究,分别采用绝缘油、绝缘胶对光导开关进行了绝缘保护,并结合介质击穿理论对试验结果进行了分析。模拟和试验结果表明:适当的绝缘保护可以有效提高耐压特性,使绝缘强度达4kV/mm。 相似文献
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本文对光导开光的原理、特性进行了分析。利用高压电源对储能电容充电,激光器在接到触发脉冲指令时,发出脉宽为2ns的光脉冲信号驱动光导开关,储能电容内存储的能量通过光导开关释放到取样电阻上,输出高压脉冲信号。通过对电路基本参数的仿真,得到了光导开关在2ns激光脉冲控制下,输出高压脉冲与控制光脉冲响应良好,上升时间为169ps,脉宽为2ns。 相似文献
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高压LDMOS功率器件的研究 总被引:2,自引:0,他引:2
提出了一种适用于高低压电路集成的LDMOS器件结构,采用Double RESURF技术和场板技术,耐压可达700伏.本文借助二维器件模拟软件MEDICI,分析了器件的参数对击穿电压和导通电阻的影响,从而实现了器件的高耐压和低导通电阻的要求. 相似文献
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设计实现了一款高耐压单刀单掷天线调谐开关,用于Sub-6 GHz的天线孔径调谐、阻抗调谐以及宽带开关.设计采用串-并联和体区自适应偏置结构,兼顾插入损耗和隔离度;此外基于传统的堆叠结构进行改进,通过设计各级晶体管的尺寸不均匀,极大程度地提高了开关并联支路承受电压的能力;通过采用两级偏置网络,减小了栅端和体端的泄露从而削... 相似文献
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并联电感同步开关(P-SSHI)电路可以提高压电能量俘获能力,但其能量俘获效率受到开关控制精准性、整流电路导通压降等因素的影响。因此,本文提出了一种将超低压降有源整流与自适应P-SSHI结构相结合的高效压电能量俘获电路。其中,超低压降有源整流的上半桥采用交叉耦合被动开关的PMOS对管结构,下半桥则采用有源电路控制开关的NMOS对管结构,从而有效地降低了整流电路的导通压降。为进一步提高电路的压电俘获效率,本文采用自适应同步开关控制的P-SSHI结构以提高开关控制的精准性。该结构通过对整流电路中的电流进行过零检测确定同步开关的闭合时刻,对L-C振荡回路中的电流进行过零检测确定同步开关的断开时刻。实验结果表明,所提电路可以实现同步开关的自适应控制,并可有效提高压电能量俘获电路的整体效率。与全桥整流电路相比,本文所提电路可将输出功率提高到235%。 相似文献
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本文了光劝BMFET作为光控功率开关的工作原理,根据理论分析和计算机模拟讨论了器件结构参数和外加偏置电路与工作特性的关系,为器件优化设计提供依据。 相似文献
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低驱动电压k波段电容耦合式RFMEMS开关的设计 总被引:3,自引:0,他引:3
设计了一种低驱动电压的电容耦合式射频微机械(RF MEMS)开关.RF MEMS开关采用共面波导传输线,双电极驱动,悬空金属膜采用弹性折叠梁支撑.使用MEMS CAD软件CoventorWare、微波CAD软件HFSS,分别仿真了开关的力学性能和电磁性能,仿真结果表明:开关的驱动电压为2.5V,满足低驱动电压的设计目标;开关开态的插入损耗约为0.23 dB@20 GHz,关态的隔离度约为18.1 dB@20 GHz.最后给出了这种RF MEMS开关的微制造工艺. 相似文献
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《Sensors and actuators. B, Chemical》2006,113(1):419-427
The potential of Pd/porous-GaAs Schottky contacts for hydrogen detection at room temperature is presented. The Pd/porous-GaAs contacts were developed using an electrochemical system in our laboratory. Using both forward- and reverse current–voltage (I–V) characteristics we have found that the Pd/porous-GaAs Schottky diode sensor exhibited very high sensitivity towards hydrogen gas. The Pd/porous-GaAs diode sensor submitted to 500 ppm hydrogen gas at room temperature revealed a considerable increase in sensitivity of more than three times higher than that of the Pd/GaAs sample. The significant changes observed here have been found to be due to the results of a decrease in effective barrier height of the Schottky contact. This is due to a lowering of metal work function and eventually the creation of a dipole layer on the semiconductor surface induced by dissociation of hydrogen atoms on the Pd contact, followed by diffusion to the Pd/porous-GaAs interface. A comparative study has been conducted to show the differences between Pd/GaAs and the Pd/porous-GaAs Schottky contacts fabricated at different conditions and subjected to hydrogen gas at various operating temperatures. Scanning electron microscopy (SEM) was used to examine the porosity of the GaAs surfaces. SEM pictures showed highly porous structures of the Pd/porous-GaAs Schottky contacts provided for penetration of hydrogen gas molecules. 相似文献
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A micro coplanar Wilkinson power divider at X-band on GaAs substrate is presented in this paper. The proposed power divider introduces a size reduction method, and the length of the transmission line is reduced to λ/8 (at 10 GHz). Since the two segments of the two edge coupled quarter-wave asymmetric coplanar striplines (ACPSs) with finite-width ground plane are closed to each other, their characteristic parameters, such as characteristic impedance and attenuation coefficient, are obtained using the quasi-static conformal mapping technique (CMT) of coupled coplanar waveguide (CCPW) with finite-width ground plane. S-parameters for the power divider are deduced in the case of quasi-static TEM even–odd mode. The fabrication process is compatible with the GaAs MMIC process. The measured S-parameters are compared with the simulated results of HFSS v.11 and the calculated results of TEM even–odd analysis. Simulated results show that it has reflection loss less of 16.5 dB and insertion loss less of 3.6 dB. Measured results show that the divider has reflection loss less of 15.0 dB and insertion loss less of 3.5 dB. Compared with conventional Wilkinson power divider, the length of the power divider is shortened from 2,620 to 1,570 μm. 相似文献
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The ability to achieve fast fluid flow yet maintain a relatively low temperature rise is important for AC electrothermal (ACET)
micropumping, especially in applications such as bioMEMS and lab-on-a-chip systems. In this paper, we propose a two-phase
ACET fluidic micropump using a coplanar asymmetric electrode array. The proposed structure applies a two-phase AC voltage,
i.e., voltage of phase 0°/180°, to the narrow electrodes while the wide electrodes are at ground potential. Numerical simulation
demonstrates that this simple coplanar electrode configuration can achieve at least 25% faster fluid flow rates than using
a single AC signal. By selecting certain design parameters, a two-phase ACET structure can achieve up to 50% faster fluid
flow rates than a corresponding single-phase structure. The simple two-phase AC signal sources are easily produced by using
inverter buffers, which is a considerable improvement compared to the multi-phase AC signals required by other electrokinetic
micropumping methods, such as traveling wave structures. 相似文献
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A square indicator using multilayer coplanar waveguide transmission lines on a GaAs fabricated by using monolithic microwave integrated circuits (MMIC) technology is presented. The polyimide layer formation, curing and dry etching processes are used in an attempt to obtain high quality dielectric layers suitable for MMIC applications. The experimental fabrication progress provides two metal layers with two polyimide spacer dielectric layers. A brief overview of the electromagnetic design process is included. The performance of the proposed spiral inductor is investigated experimentally and with electromagnetic simulations (Sonnet em) up to 20 GHz using RF‐on‐water measurements. A very good agreement is achieved, despite the highly three‐dimensional nature of the structure. ©1999 John Wiley & Sons, Inc. Int J RF and Microwave CAE 9: 86–92, 1999 相似文献
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《Sensors and actuators. A, Physical》2000,79(1):71-75
This work fabricates a novel type of micromachined microwave switch on a semi-insulating GaAs substrate using a microactuator and a coplanar waveguide (CPW) using electrostatic actuation as the switching mechanism. The microactuator uses several continuously-bent cantilevers connected in series. A cantilever with two sections, a straight-beam section and a curved-beam section, forms the basic unit of the microactuator. The straight-beam section is made of an aluminum (Al) layer, 0.5 μm thick. The curved-beam section is made of an Al layer of the same thickness, combined with a 0.1-μm layer of chromium (Cr) film. This section is initially curled due to the different residual stress of Al and Cr. The low temperature (250°C) process ensures that the switch is capable of monolithic integration with microwave and millimeter wave integrated circuits (MMIC). When no dc potential is applied, the actuator is curled far from the signal line of the CPW, and therefore the insertion loss at this `on' state is only 0.2 dB at 10 GHz. Because the metal microactuator is far from the signal line of the CPW at this `on' state, the microwave propagation is hardly disturbed by the microactuator. When an applied electrostatic force pulls the actuator tip down into contact with the signal line of the CPW, it creates a large capacitance between the actuator and the CPW. The isolation at this `off' state is −17 dB at 10 GHz. Maintaining the actuator in the `off' state requires only a very low actuation voltage of 26 V. Once the dc potential is removed, the residual stress of the actuator structure pulls it to the up position. The microactuator moving back and forth between these two switching states, acts like the movement of a frog's tongue. This switch has excellent performance at the wide-band RF frequencies used in transmit/receive modules of wireless communication. This study measured the critical corrupt (activating) voltage and recovery voltage of the microactuator. The 10-ms switching time of this switch is slower than the switching time of solid-state switches. 相似文献
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Farahiyah Mustafa Norfarariyanti Parimon Abdul Manaf Hashim Shaharin Fadzli Abd Rahman Abdul Rahim Abdul Rahman Mohd Nizam Osman 《Microsystem Technologies》2010,16(10):1713-1717
The Schottky diodes enjoined with coplanar waveguides are investigated for applications in on-chip rectenna device applications
without insertion of a matching circuit. The design, fabrication, DC characteristics and RF-to-DC conversion of the AlGaAs/GaAs
HEMT Schottky diode is presented. The RF signals are well converted by the fabricated Schottky diodes with cut-off frequency
up to 25 GHz estimated in direct injection experiments. The outcomes of these results provide conduit for breakthrough designs
for ultra-low power on-chip rectenna device technology to be integrated in nanosystems. 相似文献
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The average power‐handling capability (APHC) of the signal line in finite‐ground coplanar waveguides (FGCPWs) on polyimide and GaAs substrates is evaluated in this paper. In our approach, the ohmic loss of metal lines is characterized in different ways, and the effects of an irregular edge shape are also considered. The rise in temperature of the signal line is determined by single‐ and double‐layer thermal models, with the temperature‐dependent properties of the thermal conductivity of GaAs material treated appropriately. Parametric studies are carried out to investigate the overall effects of signal‐line width, thickness, conductivity, edge‐shape angle, and polyimide thickness on APHC. Some possible ways to enhance the APHC of these FGCPWs are also proposed. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005. 相似文献
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Abstract— The equations for the transfer characteristics, subthreshold swing, and saturation voltage of double‐gate (DG) a‐IGZO TFTs, when the top‐ and bottom‐gate electrodes are connected together (synchronized), were developed. From these equations, it is found thatsynchronized DG a‐IGZO TFTs can be considered as conventional TFTs with a modified gate capacitance and threshold voltage. The developed models were compared with the top or bottom gate only bias conditions. The validity of the models is discussed by using the extracted TFT parameters for DG coplanar homojunction TFTs. Lastly, the new pixel circuit and layout based on a synchronized DG a‐IGZO TFT is introduced. 相似文献