Topology bandpass filters in coplanar strip lines

We report a new bandpass filter on coplanar strip (CPS) lines for RF and microwave applications. The filter is implemented as electrode topology on the CPS electrodes. The topology consists of basic electrode patterns that emulate inductors and capacitors in a two‐port filter section. In the design process, equivalent circuit model is used to identify the initial topology, which is then fine tuned using full wave analysis. The bandpass filter is very compact in size and planar in structure. It does not use quarter‐wavelength sections, vias, or bonding wires. It can be fabricated without incurring additional cost. Bandpass filters for the 2.4 GHz ISM (Industrial, Scientific, and Medical) band were designed, fabricated, and measured. The measurement responses agree well with the full‐wave simulation results. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008.     

一种通用双模双2阶模拟滤波器的设计

针对目前模拟滤波器存在的一些不足,提出了一种通用双模(电压模式和电流模式)双2阶的模拟滤波器设计。它基于双输出第二代电流控制传输器,电路结构简单,仅由2个DO-CCCⅡ和2个电容器构成,电路能够提供电压模式或电流模式滤波器而不改变电路的拓扑结构,带宽和固有频率可以通过输入偏置电子调谐,每个功能响应可以通过采用数字方法适当地选择输入信号来进行选择,从而实现完全标准的低通(Low-Pass,LP)、高通(High-Pass,HP)、带通(Band-Pass, BP)、带阻(Band-Reject, BR)和全通(All-Pass, AP)功能。对所设计的滤波器采用PSPICE仿真程序得到的仿真结果与理论预期值吻合得非常好,而且最大功耗在±1.5 V电源电压时约为1.76 mW。     

Inline and canonical stripline filters with ridge coupling sections for LTCC applications

Inline and canonical filters employing stripline resonators coupled by evanescent‐mode ridge waveguide sections are presented. The proposed configurations are suitable choices for broadband chip filters integrated in printed circuit boards, especially for those with constraints on size and loss. Low temperature co‐fired ceramic (LTCC) technology can be used to manufacture such filters. To validate the idea, prototypes of Chebyshev and elliptic function filters are designed following a systematic procedure. Stepped impedance stripline resonators are used in the Chebyshev filter to improve the spurious response. A novel canonical structure is presented for achieving high selectivity elliptic function filter responses. Rigorous mode matching method is applied to analyze and optimize all the filters, whose results are validated by commercial software. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009.     

EXSHOF: An artificial intelligence approach to high-order filter synthesis

A two-tier expert-system-based synthesis of high-order filters is developed. Expert-system techniques have been used for choosing a particular biquad structure and for selection of the high-order filter structure as well. The data inputs will be either filter specifications or transfer functions and the output will be a detailed filter circuit with all its element values. EXSHOF ( pert System based ynthesis of igh rder ilter) is totally menu-driven and highly interactive. It assumes little knowledge of computers or filters from the user. The complete package is implemented in Turbo PASCAL and Turbo PROLOG languages.     

一种用于数字下变频的高阶分布式FIR滤波器及FPGA实现

设计了一种用于数字下变频的256阶分布式FIR滤波器.通过分析分布式FIR滤器结构给实现电路所需资源和运算速度带来的影响,确定了适用于Cyclone Ⅲ系列FPGA的实现结构.在Cyclone Ⅲ系列EP3C40F484C6N芯片上实现该算法并分析了资源消耗与电路速度.     

Computer‐aided design of planar bandpass filters

This article presents a simple computer‐aided design method for planar bandpass filters. The filter is sequentially designed, based on the equivalent circuit of subfilters. A filter with optimal responses may be obtained. If it needs the second design iteration, the designed filter is very adequate to serve as an initial guess for optimally adjusting. Three filters were designed and tested. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008.     

静电悬浮转子微陀螺信号发生电路有源带通滤波器设计

信号发生电路是静电悬浮转子微陀螺系统的重要组成部分。介绍了DDS信号发生电路的原理及基本构成和微陀螺信号电容检测的要求、特点以及主要技术指标,并根据具体带宽、中心频率的要求,设计了具有不同参数的有源滤波电路。通过电路模拟仿真实验表明了该电路的可行性之后,在具体实验的操作过程中,成功滤去了DDS信号发生电路所产生的低频直流偏置和高频噪声,从而提高了电路的整体信噪比和控制精度,并为后续静电悬浮转子微陀螺检测控制电路提供了较为理想的信号源。     

并联有源电力滤波器控制方式研究

针对无损耗电阻器的并联有源电力滤波器，采用一种控制算法，可实时计算出开关阵列的导通时间，实现更精确的控制。仿真结果表明，该滤波器及控制算法具有良好的谐波补偿效果。     

一种基于DO-OTA和CCⅡ-实现的n阶多功能滤波器

提出了用信号流图法设计n阶基于运算跨导放大器(OTA)和第二代电流传输器(CCⅡ)电流模式多功能滤波器的方法。该滤波器由具有双输出端的DO-OTA和第二代电流传输器(CCⅡ-)及接地电容构成。适当选定输出电流信号可同时实现低通、高通、带通、带阻以及全通5种滤波功能,而电路内部结构及器件数目无需改变。与同类电路比较,设计更简便、结构更简单、无源元件全部接地、易于集成。该滤波器可用于通信、电子测量与仪器仪表的信号处理。给出了滤波器的设计实例,PSPICE仿真结果与理论分析相吻合,验证了该方法的可行性。     

压电式双振子微型发电机功率调节电路设计

为克服压电式单振子微型发电机通过一般整流、滤波和储能控制电路不能连续为瞬时发射功率较大的无线传感器网络发射模块供电的问题,提出了一种双振子振动发电的结构思想,介绍了双振子振动发电原理;提出了一种双振子微型发电机输出功率调节控制电路技术方案,它由主一辅整流电路、主储能器、滤波器、辅助补充能量控制电路、稳压电路、滞回比较器、开关控制电路和电子开关等组成.经实验证明:封装了该功率调节电路的压电式双振子微型发电机平均输出功率为250～950 μw,瞬时输出功率可以达到680 mw,而自身的功耗只有40微瓦以下,能满足连续振动环境中微功耗电子器件、传感器或间歇式较大功耗遥测电路供电的要求.     

高阶∑△ADC中的抽取滤波器的设计

从电路实现和降低功耗的角度出发,优化并改进了梳状滤波器结构,同时设计了 FIR 补偿滤波器对其通带衰减进行补偿,通过合理的硬件电路安排来节省面积、提高速度,最终完成了高阶∑△ADC 中的抽取滤波器的设计。经过 Matlab 仿真,该滤波器阻带衰减为-65dB,通带纹波为±0.05dB,过渡带为0.454fs～0.583fs,经过 VerilogXL 和系统验证,该滤波器完全满足∑△ADC 的系统要求。     

LFM脉冲压缩的FPGA时域实现

为解决频域法实现线性调频(LFM)脉冲压缩时硬件开销较大的问题,采用时域法实现。针对间距为20m的两目标LFM信号,设计了一款64阶分布式FIR时域匹配滤波器;采用全流水线并行处理结构实现,并利用FPGA的ROM宏模块构建查找表代替乘法运算,既提高了运算速度又减小了硬件开销。基于FPGA器件EP2C35F672C8完成了LFM信号时域脉冲压缩的逻辑设计与集成。仿真结果显示,系统占用2268个逻辑单元、1573个寄存器、27K字节存储器资源。     

IIR滤波器的测试及可测性设计

基于加法器测试生成,提出了无限脉冲响应(IIR)滤波器的一种通用可测性设计、测试方案.在测试模式下,通过切断IIR滤波器中的反馈回路提高了该设计的可测性.通过复用原电路中的部分寄存器和加法器来提高其可测性,降低了额外的测试硬件面积开销.该方法能在真速下高效地侦测到IIR滤波器基本组成单元内的任意固定型组合失效,没有降低电路性能.     

基于DSP的雷达信号自适应滤波器

针对调频连续波(FMCW)汽车防撞雷达实际信号的特点,设计了一种数字信号处理器(DSP)程控自适应滤波器,介绍了其原理与具体实现方法,并结合防撞雷达有用双频信号提取的实例,分析了,该滤波器的硬件结构和软件流程,试验数据表明,该自适应滤波器可以有效地去除干扰并实现有用信号的精确提取。     

CZT像素核辐射探测器读出电路的设计

CZT作为一种新型室温核辐射探测器材料,适用范围广泛,设计一种有效的CZT读出电路意义重大。采用CMOS技术设计了一种高分辨率、低功耗的CZT像素核辐射探测器读出电路。该读出电路包括电荷敏感型前置运放、整形滤波网络、放大级。运放采用PMOS输入折叠共源共栅结构,滤波网络采用简单的RC—CR结构。在GPDK 0.18μm CMOS工艺下进行的仿真,表明该读出电路的灵敏度为0.3mV/keV,探测能量范围为20～200 keV,单信道功耗为1 mW。     

Design automation of a lossless multiport network and its application to image filtering

The paper presents expert tools which are elaborated on the basis of synthesis method of lossless nonreciprocal multiport circuits, composed of gyrators and capacitors. The algorithms are written in C++ and the tools compose a user friendly environment for design automation of filters, filter pairs and filter banks. It is possible to design in this environment not only classical structures like Butterworth, Chebyshev, and Cauer (elliptic) filters. The lossless nonreciprocal prototype circuit allows to design more complex filters, including allpass sections necessary to improve filter phase characteristics. However, the most important possibility is to design multiport circuits, especially in the case of not fully determined filter specifications. On each stage of the design process VHDL-AMS is used to describe the circuits. The obtained prototype gyrator-capacitor circuit can be implemented in OTA-C, SC (switched-capacitor) or SI (switched-current) techniques to realize the filter in CMOS technology. In the paper SI technique is used for layout generation of an image filter in order to illustrate the elaborated synthesis algorithms and tools.     

An efficient dual‐band filter‐antenna design based on simplified integration methodology

In this article, a newly developed filter‐antenna synthesis and realization methodology is applied to design a planar dual‐band filtering antenna. The synthesis method is derived based on the filter synthesis theory. As a result, a coupling coefficient expression is formulized more precisely specially for the antenna matched to the filter, which is essentially different from that in filter coupling. The synthesized circuit is realized by an efficient parameters extraction process. A third‐order dual‐band filtering antenna integrated with two dual‐mode 8‐shaped resonators and a dual‐inverted‐L antenna is then implemented for example to illustrate the design procedure. The integration method facilitates an efficient and practical filter‐antenna design without complicated parameters evaluation process. Finally, the proposed filtering antenna with simple structure and controllable frequencies is developed with the use of the investigated formulations and extraction curves. The circuit is realized for 2.5/3.45‐GHz WiMAX‐band applications. The tested results agree well with the simulations, showing good passbands selectivity and out‐of‐band rejection are attained.     

滤波器的研究与仿真

主要介绍了工程上常用来作信号处理、数据传送和抑制干扰的滤波器装置.通过电路构造以及传递函数的分析研究了一阶、二阶有源滤波器.另外,还利用MATLAB语言编程对滤波器进行了简单的仿真.     

Improvement of jitter transfer characteristics of a 9.95328 Gb/s data recovery DLL using saw filter

This paper presents a design of a high-speed data recovery circuit for non return zero (NRZ) data transmission using delay-locked loop (DLL) with SAW filter. The jitter generation of the circuit is decreased by adjusting the loop gain in DLL whereas surface acoustic wave (SAW) filter with low centered frequency (f_c) improves the jitter transfer function of DLL. It is seen that the circuit using SAW filter of f_c = 1.24416 GHz and Q = 1000 provides the cut off frequency of about 600 kHz which is ∼10 times lower than that of conventional DLL circuit.     

空调EMI电源滤波电路设计与仿真

为提高空调产品的电磁兼容特性,针对典型空调EMI电源滤波电路,提出基于ANSYS仿真软件的EMI滤波PCB设计与仿真方法。分别对滤波电路中的X电容、Y电容、共模电感、差模电感等进行单独建模,搭建完整滤波电路,通过Designer对其进行S参数仿真,利用Q3D准确提取PCB的寄生参数,通过网络分析仪测试相应的滤波PCB,验证该仿真方法的正确性与有效性。