一种双频多层微带天线的设计与分析

分析并设计了一种双频多层微带天线。该天线采用上下双层贴片、三层介质基板结构和背部探针馈电,并使用电磁仿真软件HFSS 10．0对所设计的天线进行了仿真。分析仿真结果表明,该天线的工作频段为1．31～1．39GHz和1．86—1．94GHz,具有较宽的相对带宽,该天线可作为双频天线工作,并能工作在射频频段。     

影响集成电感性能的关键因素

片上集成电感是单片集成射频电路、微波电路及光电集成电路中不可缺少的重要元件。高Q值的片上集成电感是IC工作者追求的目标。衬底损耗和金属损耗一直被认为是限制集成电感品质的主要因素,文中实例为证,在尽量消除衬底损耗和减小金属损耗条件下。得出它们并不是片上集成电感的决定性限制因素。本文从电感的定义出发,得出电感螺旋线之间磁通量的相互抵消是集成电感不能获得高Q值的决定因素。并通过螺旋电感的模拟计算和结合已有的实验,对此论点进行了论证。     

金属线宽与间距渐变的片上螺旋电感设计规则研究

在分析片上螺旋电感的磁场分布及射频损耗机制的基础上,研究了电感的金属线宽及线圈间距的变化对电感性能的影响,在大量数值分析基础上提出了金属线宽与间距之和不变,而金属线宽与间距之比从外圈到内圈逐渐减小的渐变型片上螺旋电感,并得到了实验验证,多组样品的测试结果与数值分析结果相吻合,以2.4 GHz频段处为例,在高阻硅衬底上制备的5 nH渐变结构电感的品质因子Q为11,比具有相同外径和电感值的固定金属线宽及间距的传统电感高19.6%.     

MMIC用多层磁膜电感研究

采用磁控溅射生长磁膜工艺,结合BCB(苯并环丁烯)平坦化技术,首次制作了"金属线圈/磁膜/金属线圈(M/F/M)"和"磁膜/金属线圈/磁膜/金属线圈(F/M/F/M)"两种结构的多层磁膜电感,整个工艺与标准MMIC工艺兼容.在2 GHz处,"金属线圈/磁膜/金属线圈"结构电感的电感量为7.5 nH,品质因数为7.17,...     

常用间隔层材料软X射线多层膜的设计

为了研究常用间隔层材料的软X射线多层膜的材料设计,利用Lawrence-Livermore国家实验室提供的软X射线多层膜设计程序进行模拟计算,得到了软X射线波段内的具有高反射率的膜系。结果表明,Mo在相当大的波段范围内具有良好的光学特性;除了在12.44nm是首选膜系外(除4.36nm外),其它波长都有较高的反射率;U作为吸收层材料,在相当大的波段范围内,与其它间隔层材料配对的多层膜也具有较高的反射率。这对多层膜膜系的材料选择有一定的指导意义。     

一种月牙形缝隙多频微带天线分析与设计

提出了一种微带馈电式圆形微带天线设计方案,通过在辐射贴片表面加载月牙型缝隙,改变电流有效路径,实现多频特性。通过HFSS仿真分析缝隙形状对天线性能的影响。结果表明,天线工作的三个频段相对带宽分别为4.1%(2.39~2.49 GHz),3.98%(3.92~4.08 GHz)和3.75%(5.51~5.72 GHz)。其中低频和中频段的最高增益达到6.58d B和5.01 d B。天线尺寸为35 mm×52 mm,具有小体积、高增益、全向性良好的特点,能够应用于无线通信系统中,并且这种结构简单、参数少、多频段的设计方法为天线设计提供了新的途径。     

AlN多层共烧陶瓷微波外壳的设计与制作

使用Ansoft HFSS软件设计了一种微波多芯片组件(MCM)用陶瓷外壳,并采用AlN多层共烧陶瓷工艺制作了样品。微波输入输出(I/O)端子采用微带线直接穿墙形式,并与陶瓷外壳一体设计、制作。试验结果表明,在2～12 GHz内驻波比(VSWR)<1.3,测量漏率R1≤1×10–3Pa.cm3/s(He)。     

基于HFSS的多频微带天线分析与设计

设计了一种缝隙多频微带天线。通过在微带天线贴片上加载缝隙改变电流分布,从而实现微带天线的多频谐振。用HFSS软件对其进行仿真分析实现参数的优化设计,在1~6 GHz内得到了3个谐振频率:2.43,4.40和5.27 GHz,其回波损耗分别为:–31.84,–32.82,–29.62 d B。当回波损耗小于–10 d B时,相对带宽分别为:3.29%,1.41%,2.05%。该多频微带天线具有体积小、回波损耗低等优点,可用于无线通讯系统。     

多层陶瓷封装外壳的微波设计

随着微电子器件的发展，集成度越来越高，不断向高频、高功率应用迈进，对其封装技术的发展也提出了更高要求。本文以一个场效应管封装外壳的微波设计为例，探讨了微波三维结构仿真技术在封装外壳设计上的应用，证明对封装外壳进行合理的微波设计，可以有效地提高器件的微波性能。     

金属线宽及线间距渐变的射频螺旋电感

为减少射频螺旋电感的金属导体损耗,提出了一种电感金属线宽及金属间距从外到内逐渐变小的新颖结构.与传统的固定金属线宽和间距的电感相比,该渐变结构电感涡流效应的影响较小,金属导体损耗减小,从而降低其串联电阻,品质因子Q值提高.实验结果确证了所提方法的正确性.对一个高阻硅衬底上6nH电感,优化设计的渐变结构电感Q值在2.46GHz处可达到14.25,比版图面积相同、固定线宽及间距的传统电感高11.3%.因此,在无线通信系统的射频前端,采用这种电感与射频集成电路结合,能获得更好的射频电路性能.     

高Q值平面螺旋电感的多电流路径结构设计

通过将平面螺旋电感器中的单股宽导线分成并联的多条细导线而在电感中形成多电流路径结构,可以降低电感的高频损耗并提高其品质因数(Q值)。利用HFSS电磁仿真软件对具有多电流路径结构的螺旋电感进行了设计与优化。结果表明,在尺寸不变的情况下,采用了多电流路径结构的平面螺旋电感的Q值提高了80%以上,这为高Q值小型平面螺旋电感的研制提供了思路。     

A low power tunable inductor based on active capacitor with negative resistance

A method to provide a low power tunable inductor is presented in which the inductance and its equivalent series resistance can be independently tuned. This equivalent series resistance can be also set to negative or zero value that is corresponding to inductor with ideal quality factor. In this method, a varactor is placed in parallel with a passive inductor and then, an active capacitor is placed in series with them. To this end, a low power Tunable Active Capacitor (TAC) is proposed which is capable of generating tunable capacitor and large negative resistance to compensate the loss of tunable inductor circuit. Also, the power consumption is low because of using a diode-connected transistor. A prototype of the proposed circuit is designed and simulated at 4 GHz. The electromagnetic simulation results show the inductance tuning range of 0.48–2.3nH with zero or even negative equivalent series resistance is obtained while the power dissipation is less than 3 mW. Moreover, noise analysis shows that higher inductance translates to lower noise while there is a weak correlation between noise and quality factor of the obtained inductances.     

Design and testing of a power electronic synthetic inductor

In many applications inductors are often replaced with circuits, typically based upon operational amplifiers, which emulate an inductance for reasons of package size or to closer approximate the desired ideal behaviour. A power electronic synthetic inductor offers an alternative circuit which can emulate an inductor with relatively low power consumption, as well as provide a flexible circuit topology that is not limited to inductive behaviour. In this article, a power electronic synthetic inductor topology and control system is developed. A prototype synthetic inductor was built and tested, and its operation was explored and compared with an operational-amplifier-based synthetic inductor. A minor modification of the circuit allows the emulation of a negative resistance in parallel with the synthesised inductor, which can increase the quality factor of the system beyond that associated with an ideal inductor. Experimental results reveal that the power electronic synthetic inductor has significantly lower power consumption than an operational-amplifier-based synthetic inductor.     

13.56MHz RFID读写器天线的设计与仿真

为提高13.56 MHz RFID读写器天线的发射效率,并使其天线在实验室易于研发和试制,对13.56 MHz RFID天线系统的工作原理进行了简要介绍,在此基础上,把13.56 MHz RFID读写器天线线圈等效为PCB平面螺旋电感,利用HFSS软件建立模型并仿真得出电感值L、品质因子Q值等参数。其仿真结果得到的电感值与理论计算值相差0.03μH,在可接受的范围内。考虑到实际天线产生的寄生电容,提出了在天线末端加开路补偿线圈的方法,避免因寄生电容产生地电流而使天线线圈的磁场强度降低,仿真结果证实了该方法的可行性。     

基于闭合磁路的框式薄膜电感的研究

通过磁控溅射工艺制备出三种框式薄膜电感,其中特殊磁芯电感、全磁膜电感为设计制作的具有闭合磁性回路的特殊薄膜电感,而三文治结构电感是目前流行的薄膜电感,这些电感均由下层磁芯层、下层绝缘层(聚偏二氯乙烯,厚度约为40μm)、线圈和线圈中心的磁膜、上层绝缘层和上层磁芯层组成,其差别在于磁芯结构不同。在1~3 MHz频率范围内,比较了三种电感的等效电感、寄生电容和损耗因子。结果表明:与三文治结构电感和全磁膜电感相比,特殊磁芯电感有较高的等效电感量和较小的寄生电容,但损耗较后两者高。     

一种电感电流同步控制和采样DC转换器设计

双向DC控制器的控制指标衡量主要包括采样和控制两个方面,本系统从电流采样角度出发,设计一种电感电流同步控制和采样转换器,在控制周期的固定位置采集数据,从而达到稳定采样的目的,且控制方式采用集中式管理分布式控制方案,可以实现多模块的并联,为后期扩展留下基础.尤其适用于DC转换器中需要对电感电流进行采样的装置,该转换器主要用来实现采样和控制同步.     

Fabrication and performance of a micromachined 3-D solenoid inductor

A high-Q and f_res (self-resonant frequency)solenoid inductor was fabricated by using the microelectromechanical systems(MEMS) technology with air-core structure. This inductor has an air core and an electroplated copper coil to reduce the series resistance, and the solenoid structure with laterally laid out structure saves the chip area significantly. The measurement results show that this inductor has high Q-factor and stable inductance over wide range of operating frequency. The maximum Q-factor of this inductor is 38 and the inductance is 1.78 nH at 5 GHz with an air core of 45 μm. Moreover, the Q-factor and the inductance grow with the increasing of the air core.     

双轴同轴型微波介质滤波器的仿真与设计

在介绍双轴同轴型谐振微波介质滤波器结构及工作原理基础上,利用理论公式计算与HFSS10.0三维有限元仿真的混合设计方法,设计了满足性能要求(插入损耗为–3dB以上;–3dB带宽为18MHz以上)的微波介质滤波器。滤波器试样实际测试结果表明,该设计方法正确可行,测试结果与仿真结果有很好的一致性,最终设计出的滤波器插入损耗为–2.83dB,–3dB带宽为35MHz。     

多层介质天线罩的数值分析

针对含有多层薄层介质的电大尺寸多尺度问题计算的难点,提出了多层薄层介质的等效阻抗边界条件,该边界条件计入了薄层介质引起的电磁场幅度和相位的变化,可简化含多层薄层介质电磁结构的计算,解决多层天线罩薄层介质引起的剖分奇异化问题,实现多层天线罩对于天线性能影响的数值研究。     

Low-loss active inductor with independently adjustable self-resonance frequency and quality factor parameters

This work presents a new low-loss active inductor whose self-resonance frequency and quality factor parameters can be adjusted independently from each other. In order to achieve this property, a new input topology has been employed which consists of cascode structure with a diode connected transistor. Furthermore, the proposed input topology makes the device robust in terms of its performance over variation in process, voltage and temperature. Additionally, RC feedback is used to cancel series-loss resistance of the active inductor, which allows self-resonant enhancement as well. Schematic and post-layout simulation results show the theoretical validity of the design. To validate the design feasibility for process, voltage and temperature changes, Monte Carlo and temperature analysis are done. Suggested structure shows inductor behavior in the frequency range of 0.3–11.3 GHz. Maximum quality factor is obtained as high as 2.1k at 5.9 GHz. Total power consumption is as low as 1 mW with 1.8 V power supply.