LC阶梯网络的分析与设计

对阶梯网络进行了综合分析，给出了用传输参数表示的LC阶梯网络传递函数的一般形式．同时，介绍了根据给定LC阶梯网络的传递函数，设计网络中元件的参数，以满足阶梯网络传递函数的要求．     

Ladder‐lattice bulk acoustic wave filters: Concepts,design, and implementation

This article presents a study of ladder‐lattice bulk acoustic wave (BAW) filters. First, a review of BAW technology and filters topologies is addressed. Next, a mixed ladder‐lattice BAW filter for application on W‐CDMA reception front‐ends (2.11–2.17 GHz) is presented. An improved solidly mounted resonators (SMR) technology was used for the filter implementation. The filter synthesis methodology is briefly described. Layout guidelines are discussed enabling an optimized filter design. The filter on‐wafer measurement results are as follows: ?3.55 dB of insertion loss, ?8.7 dB of return loss, an isolation higher than ?47 dB at the transmission band (1.92–1.98 GHz) and an improved selectivity (?30 dB at 2.14 GHz ± 60 MHz). Therefore, we can observe that the mixed topology combines the advantages of ladder and lattice networks, having very steep responses and an improved isolation at undesired bands. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008.     

关节r－p_n×p_2的K－优美性结论

本文证明了当ｒ＝１，２时，梯ｒ－ｐ_ｎ×ｐ_２为Ｋ－优美图，其中Ｋ为任意非负整数①。     

三逆变桥的组合逆变/充电器主电路设计

在单个逆变桥的基础上,为了获得输出波形接近正弦波的阶梯波,设计了一个新颖的逆变/充电器,其最大特点是3个逆变电路的输出各通过一个变压器进行升压,且3个变压器串联输出.通过控制MOSFET的通断,输出是一个接近正弦的阶梯波.再通过简单的滤波,最后得到非常好的正弦波.     

PLC在高性能压力机中的应用

本文以JB21-250型压力机电气系统为例叙述PLC在高性能压力机中的应用。     

Generalized analytical formulae to compute electrical characteristics of a homogenous ladder network of the transformer winding

Many electrical systems are expressed as a complex ladder network consisting of combinations of resistances, inductances, and capacitances. Computation of electrical characteristics, such as voltages, currents, and equivalent impedances of these ladder networks require the solution of complicated differential‐algebraic equations that are quite tedious and cumbersome. The earlier works have given particular attention to purely resistive ladder networks ignoring the inductance and capacitance parameters. Moreover, there are no direct expressions available to quickly compute these characteristics. This paper derives generalized analytical expressions that can be directly used to obtain the electrical characteristics of a finite as well as semi‐infinite homogenous ladder network by simply plugging the values of its constituent parameters. Expressions are deduced for excitation source applied to the input terminal and across 2 arbitrary nodes, respectively. Kirchhoff mesh and node laws along with ordinary algebra and trigonometric theorems are applied to derive these expressions. Boundary‐value technique is used to circuit equations to determine unknown coefficients of the expressions. The derivation given in these paper would surely help the readers to quickly compute the electrical characteristics without solving recursive circuit equations and avoiding complex state‐space matrices.     

S波段低插损FBAR陷波器的研制

该文介绍了一种单端口、端口阻抗50Ω的S波段薄膜体声波谐振器(FBAR)陷波器,其采用了梯形拓扑结构与外围匹配电路相结合的方式.对FBAR陷波器芯片的设计过程、工艺实现进行了说明.测试制备的FBAR陷波器,其陷波频段为2399～2412 MHz,陷波抑制达35 dBc;通带频率分别为1800～2300 MHz和2500...     

仪表气源干燥控制系统

以可编程序控制器（ＰＣ）为核心部件，对火电厂仪表气源干燥控制系统进行了设计。简述了仪表气源干燥控制系统的组成、工作原理及所实现的功能。给出了按步进式控制原理构成的系统的梯形图和程序表。实际运行表明：该系统具有安全、可靠、控制功能完善、容易维护、操作方便、易于推广等特点。     

多维滑动和（MA）模型参数的自适应估计

本文利用AR模型LS梯格滤波的有关公式给出了实时辨识多维MA模型参数的递推算法,该算法建立在对模型噪声和观测的自协方差阵和互协方差阵的矩估计基础上,由一个N阶反馈形式的梯格滤波器构成,可关于时间和阶次双重递推,该算法计算量为O(N)的量级,并具备梯格滤波固有的良好数值及结构特性。     

一种射频体声波滤波器的版图设计与仿真

射频体声波滤波器品质因子高,尺寸小,其性能已超过声表面波滤波器,将其替代传统的射频滤波器极具性能和价格优势。本文建立了适用于体声波滤波器性能分析的巴特沃斯—范戴克（MBVD）模型,采用梯形级联方式设计了一种射频体声波滤波器的版图。在此基础上以中心频率为1.99GHz,带宽56MHz的体声波滤波器为例,对不同连接级数梯形滤波器的插入损耗、阻带抑制进行了仿真与分析讨论,在4阶滤波器中其带外衰减达到了-29.708dB。采用微机电机械系统工艺制备的2阶和3阶滤波器传输特性的测试曲线与仿真结果基本吻合,表明射频体声波滤波器具有广泛的应用前景。该模拟结果可作为射频体声波滤波器设计的一个重要参考。