X波段上变频器设计研究

针对微波上变频器进行研究与设计。主要采用微带电路的形式完成电路的设计。采用HMC412MS8G微波单片集成电路完成微波上变频器研究,重点是利用ADS软件完成了中心频率为11.5 GHz的平行耦合线微带带通滤波器设计和测试。完成了上变频电路板的设计、安装与测试。     

一种基于ADS优化的微带带通滤波器设计及实现

介绍微带带通滤波器ADS全局优化设计方法及其设计流程,重点阐述ADS设计流程中的参数优化、器件仿真、矩量法分析等相关内容.微带带通滤波器实物的性能测试表明:通带传输衰减小于2.5dB,端121反射系数小于-15dB,阻带衰减接近40dB,其物理尺寸约8×2.5×1.5cm,基于ADS优化的微带带通滤波器设计优于传统设计.     

具有寄生通带抑制的微带带通滤波器的设计

寄生通带的抑制程度是微带滤波器的关键性能参数之一.介绍了1种能够在较宽频带内有效抑制寄生通带的设计方法,通过将带通滤波器和低通滤波器级联、联合仿真优化,最终得到在通带的二倍频与三倍频区域都具有足够抑制的微带带通滤波器原型.给出了具体的设计原理,以及使用ADS和Ansoft Designer的设计步骤与流程.最后的实测结...     

应用于SAW RFID中带通滤波器的设计与仿真

本文借助于平行耦合单元,使用ADS（Advanced Design System）仿真软件,设计出一种高性能的带通滤波器,介绍了其设计仿真的全过程,给出了电路仿真结果,并对仿真结果进行了分析。设计出的带通滤波器可用于2.45GHz声表面波射频识别读卡器,其优点在于制作过程简单,性能指标高,能满足预期期望值。     

用于微波集成电路的有限极频小型YIG带通滤波器

描述了一种微小型窄带二级YIG带通滤波器,它可编入微带线路中,其选择性由于引进了有限极频而得以增大。由于连接到YIG耦合区的输入输出线之间的附加的耦合,这是可实现的。     

采用双开口方谐振环对的紧凑微带双频带通滤波器

提出了一种零度馈电、具有开口谐振环对的紧凑微带双频带通滤波器,适用于短距离无线通信2.4GHz频段和3.5GHz固定无线接入(FWA)的频段。此滤波器使用开口谐振环作为基本谐振器单元,通过电耦合实现了第一带通特性,通过调谐内外环的间距产生第二通带。为了提高带外衰减,通过设计零度馈电结构来引入四个传输零点,从而获得了高选择性特性,该滤波器设计简单、结构紧凑。最后,仿真设计和制作了滤波器样品,仿真与实测吻合较好,满足了设计要求。     

新型吸收式微带线带通滤波器的仿真设计

基于传统的梳妆线谐振式滤波器设计原理及微带线定向耦合器理论,提出了一种新型的吸收式带通滤波器,其特点是滤波器的电压驻波比不仅在通带内很好,通带外很大频率范围内驻波也小于3.5,这也是该滤波器与常用的反射式滤波器的区别。首先,该滤波器采用微带线结构实现,与传统LC结构滤波器相比,可应用于更高的频段;其次,该滤波器具有较宽的带宽;再者,该滤波器设计灵活简单、成本低、易于集成。通过MWO软件仿真优化,实现了通带中心频率为3500MHz、3d B带宽为479MHz、通带内插入损耗小于3d B、通带内电压驻波比小于2、带外驻波比在很大频率范围内小于3.5的新型微带吸收式带通滤波器的设计。     

C波段高阻带抑制的微带带通滤波器设计

在二三次谐波处是否具有比较高的衰减是衡量低通和带通滤波器性能的重要指标之一.为了实现带通滤波器在二三次谐波处能有比较高的衰减,利用将发夹形带通滤波器与椭圆微带线低通滤波器串联的形式来实现此目标,其中串联椭圆微带线低通滤波器是为了更好的衰减二三次谐波.给出了利用ADS和Ansoft Designer的具体设计过程.最后测试结果表明:该滤波器通带内插入损耗小于4 dB,二三次谐波处具有50 dB衰减,整个阻带内衰减大于50 dB,满足了实际应用需求.     

基于并联负载发夹型谐振器的四阶带通滤波器

针对现代无线通信系统中平坦带通滤波器的需求,提出了一种并联负载的发夹型谐振器,并利用提出的谐振器构建了四阶平坦带通滤波器。首先,通过在发夹型谐振器磁场最强的位置（中心位置）设置电阻,设计了一种新的并联型谐振器,从而可以通过改变电阻值来灵活地调整固有品质因数;其次,采用具有高、低固有品质因数的耦合拓扑来构建四阶平坦带通滤波器。最后,在印刷电路板上制备了一个具有传输零点和平坦带通的四阶带通滤波器。实验结果表明,该四阶带通滤波器的实测结果与仿真结果吻合较好,与其他多阶带通滤波器相比,该四阶带通滤波器具有可灵活控制的固有品质因数和小于0.2dB通带平坦度。     

一种新型微带开环滤波器的设计

对于现代移动通信设备对微波滤波器的小型化、高带外抑制的要求,提出1种基于开环谐振子的微带带通滤波器.通过一定数目的开环谐振子,产生1对传输极点,提高滤波器的带外抑制,讨论了这种滤波器的设计流程,包含了相应的公式以及精确的计算.实际设计了1个八阶开环滤波器,中心频率为1 123 MHz,相对带宽为9.534%,带外50 ...     

Compact third-order microstrip bandpass filter designed by the distributed- to lumped-element equivalence

In reality, it is not easy to design microstrip filters for the sake of distributed-element effect. It is an effective approach to approximate distributed-element structures through appropriate lumped-element circuits. In this paper, some basic microstrip structures are discussed, whose equivalent lumped-element circuits are derived. Then, a novel microstrip filter is obtained by connecting these microstrip structures, according to the similar topology of the third-order lumped-element bandpass filter. The equivalent lumped-element counterpart of the proposed microstrip filter clearly reveals its physical mechanism, ie, how the resonances are created and coupled and how the transmission zeros are created. Furthermore, a set of the design formulas are presented, which can be used to calculate initial structure parameters and then facilitate design process. The proposed microstrip bandpass filter can realize a third-order elliptic bandpass response with one transmission zero at each side of the passband. In addition, two short-circuited stubs are added to input/output ports to create the third transmission zero. The filter is featured by good frequency selectivity and out-of-band suppression. For demonstration, an actual example was designed, fabricated, and measured.     

Modeling of bandpass filter using defected ground structure and defected microstrip structure

In this present work a novel concept for designing of tunable bandpass filter has been introduced with the help of end coupled microstrip transmission line, defected ground structure (DGS) and defected microstrip structure (DMS). Utilizing this concept, one bandpass filter of 8 GHz center frequency with 30 % fractional bandwidth (FBW) at ?3 dB has been implemented for the applications of X-band communication systems. The structure has been simulated with Method of Moment (MoM) based IE3D EM simulator and Measured with Agilent make vector network analyzer of model N5230A. Finally, the simulated result and measurement result provides good agreement between them.     

Optimal design of third‐order microstrip bandpass filters by direct synthesis technique (DST)

To design microstrip filters is not easy for the sake of their distributed‐element effect. Undoubtedly, to understand their physical mechanism is very important to their design. In this paper, one effective approach to design some third‐order microstrip bandpass filters with each of 2 transmission zeros at each side of the passband is discussed. Lumped‐element equivalent circuits are used to represent these microstrip filters. Then, these lumped‐element equivalent circuits can be synthesized by direct synthesis technique we recently proposed, so that it is likely to calculate initial structural parameters of these microstrip filters and then facilitate their design. Verified by the measured results of the filter designed through the approach in this paper, the performance of the filters is close to ideal frequency responses. Furthermore, another third‐order microstrip bandpass filter is presented, in which open‐circuited stubs at input/output ports are introduced to suppress one specified harmonic to improve out‐of‐band attenuation.     

一种用于GIS超高频检测的滤波器

为提高使用外置天线的GIS超高频检测系统的信噪比,设计了一种工作频带300~1000MHz的微带线带通滤波器。根据微带线滤波器设计原理,确定滤波器类型、结构和级数,利用先进的EDA仿真工具进行结构仿真和优化并提出了一种减小滤波器尺寸的方法。特性曲线和实测性能表明,该滤波放大器能抑制低频干扰信号,放大局放信号,提高信噪比,从而满足了UHF微弱信号滤波预处理要求。     

耦合微带线参差谐振带通滤波电路

对于微波集成振荡器或放大器输出端的滤波器,要求具有较好的抑制谐波性能,本文提出耦合微带线参差谐振带通滤波电路,它由半波长谐振器式平行耦合微带线单元电路与传输线段联构成,其特点是有利于对谐波输出的抑制。     

新型开环耦合谐振滤波器的设计与应用

为了满足日新月异的无线通信对小型化带通滤波器的要求,针对传统类型滤波器存在线性度、矩形系数、插入损耗、体积等方面的问题,笔者介绍了一种通过在微带开环谐振滤波器中引入交叉耦合,产生一对传输极点,从而提高滤波器选择性的滤波器设计方法,并讨论了这种滤波器的综合方法和实现流程。实际设计了一个六阶开环谐振滤波器,并给出了全波仿真结果。分析和仿真都表明这种滤波器具有体积紧凑、选择性高的优点。     

Combining Coarse and Fine Models for Optimal Design

In this article we reviewed the implicit space mapping concept. We illustrated it using a simple tapped-line microstrip filter example. We demonstrated the robustness of our approach by performing an accurate design of a microstrip hairpin filter. A detailed and easy-to-follow design optimization procedure was provided and the Agilent ADS implementation of the algorithm was described. A good electromagnetically validated design in Sonnet em was obtained in a few fine model simulations. Implicit space mapping is a simple approach to combine a circuit-theory based CAD model and an EM simulator model to achieve fast and accurate optimal design and modeling.     

Multiple-resonator-based bandpass filters

This article describes a class of recently developed multiple-mode-resonator-based bandpass filters for ultra-wide-band (UWB) transmission systems. These filters have many attractive features, including a simple design, compact size, low loss and good linearity in the UWB, enhanced out-of-band rejection, and easy integration with other circuits/antennas. In this article, we present a variety of multiple-mode resonators with stepped-impedance or stub-loaded nonuniform configurations and analyze their properties based on the transmission line theory. Along with the frequency dispersion of parallel-coupled transmission lines, we design and implement various filter structures on planar, uniplanar, and hybrid transmission line geometries.