A Multi-Band Transformer for Two Arbitrary Complex Frequency-Dependent Impedances

A multi-frequencies transformer for two arbitrary complex frequency-dependent impedances is presented. Design equations of the proposed transformer are derived, and particle swarm algorithm can be used to solve the resulting nonlinear equations. Some numerical examples for two-, three-, and four-section transmission line transformer were presented to verify the validity of the proposed design.     

A Dual-Frequency Transformer for Complex Impedances With Two Unequal Sections

In this letter, a small dual-frequency transformer with two unequal sections for complex impedances is proposed. To design this transformer, two different groups of nonlinear equations and the corresponding solutions processes are obtained. The results of numerical examples show that two complex impedances can be matched at two different frequencies simultaneously. This proposed transformer can be regarded as the extension of small dual-frequency transformer in two sections for two resistances.      

A Three-Section Dual-Band Transformer for Frequency-Dependent Complex Load Impedance

In this letter, we propose a practical three-section dual-band transformer, which can terminate frequency-dependent complex load impedance at two arbitrary bands simultaneously. Analytical equations are derived to achieve the exact closed-form solutions. Numerical examples are examined to verify the validity. This three-section transformer can be utilized to match the complex load impedance with unequal values at two different frequencies, such as microwave amplifiers based on transistors, mixers, various kinds of antennas, and so forth.     

任意频率比双频率阻抗变换器

讨论了双频阻抗变换器的设计方法 ,该阻抗变换器能在两个任意的频率点对任意电阻性负载实现理想的阻抗匹配 ,通过对两节传输线匹配方程的严格解 ,得到了双频阻抗变换器的精确设计公式 ,对用该方法设计的阻抗变换器性能进行了仿真分析 ,仿真结果显示了该方法的有效性 ,其结果可用于实际的设计问题。     

A Technique for Determination of Filter Insertion Loss as a Function of Arbitrary Generator and Load Impedances

Insertion loss is derived in terms of generator impedance, load impedance, and filter open-circuit and short-circuit impedances. This expression contains a difference term which places great weight on the accuracy with which filter impedances are measured. It is shown that the use of this difference term can be avoided by introducing the filter insertion loss in a circuit with known generator and load impedances. The resulting exact expression contains terms which are easily measurable with sufficient accuracy to provide reliable insertionloss values for the filter for any combination of generator and load impedances. Also shown is a simplified approximate expression for insertion loss which is applicable in a filter attenuation band. A discussion of experimental verification of the expressions is followed by curves showing application of the approximate insertion-loss expression to a particular filter.     

Generalized Reliability Function for Systems of Arbitrary Configurations

In this note we consider a special system that always requires more than one elementary path between its input and output terminals to perform its job. Since the special system may consist of components that are not series-parallel connected, the generalized reliability function for systems of parallel components introduced by Chan is insufficient for studying the reliability of this class of systems. However, an even more generalized reliability function for the special system can be obtained by generalizing the path enumeration approach (path-tracing method). The conventional reliability function and the generalized reliability function of Chan are special cases of the one derived in this note.     

一种MIMO系统中的快速广义复球形解码算法

该文提出了一种广义复球形解码算法。它能处理多输入多输出系统(MIMO)中发送天线多于接收天线的情形,并能同时检测具有格型结构和不具有格型结构的二维空间星座信号。该算法对信号矢量的超定部分进行优化搜索,从而避免了穷尽搜索的高复杂度。仿真结果表明该广义复球形解码算法的复杂度明显低于采用穷尽搜索策略的复杂度。     

三维口面衍射场的复射线展开

本文利用Ｇａｂｏｒ原理把三维任意口面场表示成离散结构－波数相位空间中三维高斯函数的叠加将二维高斯基函数与相位空间谱双重正交的函数推广到三维，从而得到口有开函数。     

一种新型低功率双频微波整流电路

提出一种应用于低功率的双频输入微波整流电路,采用双频匹配网络和直通滤波器分别实现二极管的输入匹配和抑制双频的基频与高次谐波,当输入为1 mW 时,实测结果显示,该整流电路在850 MHz 和1.9 GHz 频率处分别获得了47%和81.4%的整流效率,输出电压分别为0.53 V 和0.70 V,在输入双频信号时输出电压为0.85V,转换效率为60.8%,其低功率输入性能在国内具有先进性,并对RFID、嵌入式传感器电子设备无线输能等领域的应用具有实际参考价值。     

一种新的广义阻抗变换器模型及应用

本文在微波网络综合理论中，提出一种新的广义阻抗变换器模型，它是Ｋ，Ｊ变换器的最一般推广，可应用于带任意复杂不连续性的微波滤波器，阻抗变换器和耦合器的设计，并能解决对称和反对称网络两种情况，文中给出了设计实例。     

A Generalized Surface Integral Equation Formulation for Analysis of Complex Electromagnetic Systems

A novel method is presented to analyze the electromagnetic characteristics of systems consisting of a large number of scatterers with different shapes and materials. In the method, nearly located scatterers are grouped together, while large bulk materials are divided into subblocks with adequate sizes. A scatterer group or a subblock forms a basic block of the system, and each block is contained with a virtual reference surface. A generalized transition matrix defined on the reference surface is used to characterize the electromagnetic characteristics of the block. The generalized transition matrix relates the rotated tangential components of the scattered fields or the equivalence sources to the rotated tangential components of the incident fields directly. The generalized transition matrix can be calculated for each block independently using proper methods according to its structure and material. Surface integral equations are established on all the virtual reference surfaces, which can be solved by moment method to get the electromagnetic characteristics of the whole system. Characteristic basis functions and synthetic basis functions can be applied to further reduce the unknown number, while fast multipole method can be used to accelerate the evaluation of interactions. Two-dimensional examples are provided to verify the method.     

A Method for Calculating the Frequency-Dependent Properties of Microstrip Discontinuities

A method is described for calculating the dynamical (frequency-dependent) properties of various microstrip discontinuities such as unsymmetrical crossings, T junctions, right-angle bends, impedance steps, and filter elements. The method is applied to an unsymmetrical T junction with three different linewidths. Using a waveguide model with frequency-dependent parameters, a field matching method proposed by Kuhn is employed to compute the scattering matrix of the structures. The elements of the scattering matrix calculated in this way differ from those derived from static methods by a higher frequency dependence, especially for frequencies near the cutoff frequencies of the higher order modes on the microstrip lines. The theoretical results are compared with measurements, and theory and experiment are found to correspond closely.     

一种任意窗函数的复数调制重叠变换的快速算法

该文提出了一种任意窗函数的复数调制重叠变换(MCLT)的快速计算方法。针对输入信号长度为2M 的MCLT,该算法将其转化为长度为2M的II型离散 Hartley 变换,然后对后者运用快速算法。与现有算法相比,该方法能够达到最少的算术运算量。     

A Graphical Method for Transforming Impedances and Reflectances Through a Lossy Twoport

In this paper a simple projective geometric construction is applied to the problem of finding the input impedance of a linear lossy twoport junction for a given output port termination. The method, an extension of Bracewell's transducer diagram, is presented in both the impedance and reflectance planes.     

一种可适应复杂互连电容结构的边界元形体处理方法

针对当前集成电路中日益复杂的互连结构,提出了一种边界元电容提取中的形体处理方法,可适用于填充气隙、保形介质、多平面介质,以及任意复杂的寄生电容结构.在该处理方法中采用多叉树组织三维形体对象,并有效地生成区域边界表面的信息.数值实验表明,该方法拓宽了边界元电容提取处理复杂结构的能力,且具有较高效率.     

一种可适应复杂互连电容结构的边界元形体处理方法

针对当前集成电路中日益复杂的互连结构,提出了一种边界元电容提取中的形体处理方法,可适用于填充气隙、保形介质、多平面介质,以及任意复杂的寄生电容结构.在该处理方法中采用多叉树组织三维形体对象,并有效地生成区域边界表面的信息.数值实验表明,该方法拓宽了边界元电容提取处理复杂结构的能力,且具有较高效率.     

Two Effective Strategies for Complex Domain Compressive Sensing

In this paper, we propose two novel recovery schemes for complex domain compressive sensing. Firstly, we present a new strategy to separate the real and imaginary parts of a complex signal for \(\ell _{1}\) minimization. While the method is simple, simulation results show that it is quite efficient because it reduces the sampling rate. Secondly, the least squares (LS) sub-problem is a key part of the orthogonal matching pursuit (OMP) algorithm and accounts for a large part of the computational load. We employ the Landweber algorithm to efficiently solve the LS problem. Furthermore, we propose four new parameter options to accelerate the convergence. Our numerical experiments show that our method is competitive with the pseudo-inverse.