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硅基铝T形梁MEMS可变电容的设计与模拟 总被引:1,自引:0,他引:1
提出了一种新颖的运用于射频通信系统VCO中的RFMEMS可变电容。该电容使用平行板和T形梁结构,使用硅衬底,整个结构由铝材料组成,结构简单,与集成电路工艺兼容,从而能够实现片上可变电容。通过静电力驱动上极板向下运动,电容值相应地发生改变,当上极板加电压从2.4V变化到4.3V时,电容值从0.25pF变化到0.33pF,变化率为中心电容的27%。使用Coventor软件对该器件进行了模拟,给出的模拟结果包括容量、调节范围、瞬时响应、Pullin电压和运用该可变电容的VCO的电路模拟。 相似文献
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本文提出了一种增强型品质因素(Q)可变电容的LC压控振荡器,用于高灵敏度GNSS接收机。提出的增强的累积型MOS(A-MOS)可变电容由两个A-MOS可变电容和两个直流偏置组成,具有改善Q值和线性化电容-电压曲线的优点。数字切换的可变电容阵列(DSVA)对所有的VCO子波段进行VCO增益补偿,基于A-MOS可变电容的特性,DSVA中的可变电容关断时,其作为高Q值的固定电容,而当可变电容接入时,其作为Q值适中的调谐电容,这样保证了整个LC谐振腔的Q值最大化。提出的电路已经在0.18 1P6M的CMOS工艺上制造。测量的相位噪声低于-122dBc/Hz当偏移频率为1MHz, 通过调节子波段和控制电压,测得的调节范围为58.2%,而VCO增益变化小于?21%。当采用1.8V电源电压时,提出的压控振荡器在整个工作范围内功耗小于5.4mW. 相似文献
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射频MEMS压控电容器 总被引:1,自引:0,他引:1
研究了射频 MEMS压控电容器的设计和制造工艺。压控电容器的制作采用了 MEMS制造技术 ,其主要结构为硅衬底上制作金属传输线电极和介质层 ,然后制作金属膜桥作为电容器的另一个电极。通过改变加在金属膜桥与传输线间的电压达到改变电容值的目的。这种压控电容器可以工作于射频和微波波段 ,具有很高的Q值。测试结果如下 :在 1 GHz、0 V时 Q值达到 3 0 0 ,0偏压电容值为 0 .2 1 p F,当加上驱动电压后 Cmax/ Cmin的变比约为 4∶ 1 相似文献
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在微机械开关与硅IC工艺设计和兼容方面进行了改进,获得了一种可与IC工艺兼容的RF MEMS微机械开关.采用介质隔离工艺技术把这种RF MEMS微机械开关制作在绝缘的多晶硅衬底上,实现了与IC工艺兼容;采用在金属膜桥的端点附近刻蚀一些孔的优化方法,降低了RF MEMS微机械开关的下拉电压.用TE2819电容测试设备测试开关的电容,测得开关的开态电容、关态电容和致动电压分别为0.32pF、6pF和25V.用HP8753C网络分析仪对RF MEMS微机械开关进行了RF特性测试,得出RF MEMS微机械开关在频率1.5GHz下关态的隔离度为35dB,开态的插入损耗为2dB,用示波器测得该开关的开关速度为3μs. 相似文献
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Hung-Der Su Shou-Zen Chang Si-Chen Lee Tai-Ping Sun 《Electronics letters》1995,31(11):918-920
The Au/Cr/a-SiNx:H/(n)InAs/GaAs metal-insulator-semiconductor (MIS) capacitor was fabricated as a basic element of charge injection devices using plasma enhanced chemical vapour deposition. The electrical properties of the capacitor were analysed as a function of temperature using high frequency (1 MHz) capacitance-voltage measurements. It was demonstrated that the capacitor can still be biased into deep depletion at 180 K. When this capacitor is used as an integrated infrared detector in a charge injection device, it exhibits the capacity to detect infrared signals at a temperature of 180 K, higher than that of an InSb infrared detector (77 K), and the device can be cooled thermoelectrically 相似文献
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The AC driving scheme for OLEDs,which uses the pixel circuit with two transistors and one capacitor(2T1C),can extend the lifetime of the active matrix organic light-emitting diode(AMOLED) on silicon,but there are switching effects during the switch of AC signals,which result in the voltage variation on the storage capacitor and cause the current glitch in OLED.That would decrease the gray scale of the OLED.This paper proposes a novel pixel circuit consisting of three transistors and one capacitor to realize... 相似文献
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《Solid-State Circuits, IEEE Journal of》1979,14(6):1034-1041
Techniques are presented for the design of a second-order switched capacitor filter which has its frequency response parameters programmed by the application of digital control signals. Two different types of weighted capacitor arrays are used to achieve programmability in the center frequency, peak gain, and selectivity. Experimental results are given for an integrated NMOS version with eight logarithmically-spaced center frequencies programmed by a 3 bit digital word, and 64 Q and gain values programmed by two 6 bit words. The filter is designed so that binary changes in the sampling frequency provide new sets of center frequencies which smoothly continue the logarithmic progression. Since the response depends on monolithic MOS capacitor ratios, the accuracy and reproducibility inherent in the switched capacitor approach are retained. 相似文献
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An on-chip capacitor is formed under the bond pad to block the DC level of input signals. Capacitively coupled signals suffer the “zero wander” effect which causes the local DC level on the second plate of the capacitor to be dependent on the bit activity rate. A quantized feedback technique using a self-triggered decision circuit is used to reestablish local DC voltage levels in the receiver and eliminates the “zero wander” effect. The input signals can be detected over a large common mode range independent of the bit activity rate and over a large frequency range. Silicon area and power dissipation are reduced since encoding and decoding of the bit stream is not required. The circuit has been implemented in silicon using a conventional digital 0.5 μm CMOS technology. This receiver can detect a 231-1 pseudorandom pattern at 800 Mb/s with no errors and can operate down to a data rate of 2 kHz 相似文献
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This paper describes a delay-and-addition cell that enables direct signal processing of pulse with modulation (PWM) encoded signals. The cell can be considered functionally equivalent to a switched capacitor integrator. However, both its input and output are synchronous PWM signals. As a difference to a switched capacitor integrator, the circuit does not require operational amplifiers and is composed of passive RC circuits, switches, comparators and digital logic. Circuit implementation non idealities such as offset and propagation delays have also been analyzed. The main advantage of this circuit is the possibility to operate at a low voltage. The paper shows measurements of a demonstration circuit implementing a first order filter. As an application example, the filter is used to attenuate the quantization noise of a sigma-delta signal, delivering a continuously varying PWM waveform from a synchronous bitstream. 相似文献
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介绍了一种应用于DRAM芯片内部供电的新型低压差线性稳压器(LDO)。在传统LDO电路PMOS输出驱动管的栅端增加了一个开关电容电路,根据负载电流使能信号控制耦合电容的接入,使驱动管的栅端耦合到一个正向或者负向的电压脉冲,在负载电流急剧变化时能快速调整过驱动电压,以适应负载电流的变化。仿真结果显示,该电路有利于输出电压的快速稳定,恢复时间缩短了38%以上。采用45 nm DRAM 掩埋字线工艺进行流片。实测结果显示,该LDO输出电压恢复时间在10 ns以内。在DDR3-1600的数据传输速度下,DRAM芯片的数据输出眼图为280 ps,符合JEDEC标准。 相似文献
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半导体技术快速发展,双倍数据速率同步动态随机存取存储器(Double Data Rata Synchronous Dynamic
Random Access Memory, DDR SDRAM)的信号完整性问题已成为设计难点。文中提出了一种基于ANSYS 软
件和IBIS 5. 0 模型的DDR4 SDRAM 信号完整性仿真方法。利用IBIS 5. 0 模型中增加的复合电流(Composite Current)
、同步开关输出电流等数据,对DDR4 SDRAM 高速电路板的信号完整性进行更准确的仿真分析。仿真结果
表明:高速信号在经过印制板走线和器件封装后,信号摆幅和眼图都有明显恶化;在仿真电路的电源上增加去耦
电容后,信号抖动和收发端同步开关噪声(Synchronous Switching Noise, SSN)都得到明显改善;在不加去耦电容的
情况下,将输入信号由PRBS 码换成DBI 信号,接收端的同步开关噪声有所改善,器件功耗可以降为原来的一半。 相似文献
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针对窄脉冲激光时域/频域特性,对窄脉冲激光电路设计进行了详细的分析,包括探测器光敏面面元尺寸分析,以及取样电阻、反馈电容对信号带宽和信号完整性的影响等。为了提高探测系统的信噪比、稳定性等要素,对两种典型的光电接口电路进行了理论分析和软件仿真,得到不同的探测器结电容、取样电阻、反馈电容等参数对窄脉冲激光探测电路光电接口带宽、输出信号幅值、脉宽等响应特性的影响。根据不同种类的探测器及脉冲激光探测信号的频率特性,选取不同的偏置与放大电路,可以使前置光电接口电路的性能达到最佳。 相似文献
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文中提出了一种能在两个工作频段对高功率微波进行自适应防护的双频能量选择表面,它由两个分
别加载了二极管和集总电容的开口谐振环构成,在C 波段(5. 4~6. 0 GHz)和S 波段(2. 6~2. 8 GHz)各产生一个信号
通带。当入射波的场强超过设定阈值时,二极管被谐振环上的感应电压导通,使得谐振环的谐振状态发生变化,两
个信号通带自动关闭,从而屏蔽高功率微波。通过表面电流和电场分布阐述了设计思路和工作原理。采用PCB 工
艺制作了样件并分别在弱场和高功率辐照下进行了传输系数的测量实验。仿真和实验结果具有良好的一致性,表
明双频能量选择表面在两个信号通带的插入损耗均小于1 dB,防护效果大于15 dB(其中C 波段的信号通带内防护
效果大于25 dB),能对高功率微波进行有效防护。 相似文献