A new on-chip interconnect crosstalk model and experimentalverification for CMOS VLSI circuit design

A new, simple closed-form crosstalk model is proposed. The model is based on a lumped configuration but effectively includes the distributed properties of interconnect capacitance and resistance. CMOS device nonlinearity is simply approximated as a linear device. That is, the CMOS gate is modeled as a resistance at the driving port and a capacitance at a driven port. Interconnects are modeled as effective resistances and capacitances to match the distributed transmission behavior. The new model shows excellent agreement with SPICE simulations. Further, while existing models do not support the multiple line crosstalk behaviors, our model can be generalized to multiple lines. That is, unlike previously published work, even if the geometrical structures are not identical, it can accurately predict crosstalk. The model is experimentally verified with 0.35-μm CMOS process-based interconnect test structures. The new model can be readily implemented in CAD analysis tools. This model can be used to predict the signal integrity for high-speed and high-density VLSI circuit design     

Automated hierarchical CMOS analog circuit stack generation withintramodule connectivity and matching considerations

An efficient automated layout for CMOS transistors in analog circuits is described. The matching requirements are used as the primary constraint on the analog layout; however, parasitic capacitances and area considerations are also included. A designer-chosen arbitrary circuit partition from the schematic can be used to generate the corresponding layout as an optimum stack of transistors with complete intramodule connectivity. The transistor stack generation is performed by representing the circuit with a diffusion graph and recursively fragmenting the graph until the base constructs are reached. For each of the modules, the port structures are also created. These port structures are considered as part of the module area and parasitic optimization procedure. With aspect-ratio-related constraints, the procedure allows optimal floorplanning. The results are demonstrated through several examples     

Multifunctional microstrip transmission lines integrated with defected ground structure for RF front-end application

This paper presents multifunctional microstrip transmission lines for designing a high port-isolation dual-frequency orthogonally polarized rectangular patch antenna and the antenna-integrated power amplifier. The proposed lines were realized through the integration of defected ground structures (DGSs) with conventional microstrip lines. A spiral-shaped DGS-integrated microstrip line enhances the port isolation of the antenna, while feeding the 2.0-GHz excitation to the antenna and filtering out the 2.5-GHz receiving signal from the other port. High-order harmonic signal suppression of the power amplifier at the 2.5-GHz port was accomplished by the dumbbell-shaped DGS, thereby improving the efficiency of the amplifier. Measurements show an improvement of 20 dB in port isolation and 3% in power-added efficiency relative to an identical RF front-end, but integrated with a conventional patch antenna. An image impedance of the DGS-integrated microstrip lines can be controlled by the integrated DGS geometries. Relatively high-impedances lines, i.e., 150 and 100 /spl Omega/, are effectively implemented using microstrip lines with 75- and 50-/spl Omega/ linewidths by incorporating the spiral- and dumbbell-shaped DGSs, respectively.     

体声波传感器的系统级行为仿真

为证明六端口网络可用于体声波(BAW)传感器读出电路,对包含薄膜体声波谐振器(FBAR)和微带六端口网络的BAW传感器最小系统建立等效电路模型。在ADS软件中对FBAR建立Mason等效电路模型和对微带六端口网络建立等效电路模型。微带六端口网络的端口1连接射频源,端口2与FBAR相连,其他4个端口分别连接4个50Ω的电阻用于读取功率;在Matlab软件中分别使用根心解法和平均解法对FBAR的反射系数进行求解,解得两条反射系数与频率曲线,分析得到了两种反射系数近似计算方法的优劣,并分析了六端口网络工作频带的增宽方法。仿真结果表明,微带六端口网络能准确测量出FBAR的反射系数与频率曲线,证明六端口网络可用于BAW传感器读出电路。     

Generalized Kirchoff's current and Voltage law formulation for coupled circuit-electromagnetic Simulation with surface Integral equations

In this paper, a new formulation for coupled circuit-electromagnetic (EM) simulation is presented. The formulation employs full-wave integral equations to model the EM behavior of two- or three-dimensional structures while using modified nodal analysis to model circuit interactions. A coupling scheme based on charge and current continuity and potential matching, realized as a generalization of Kirchoff's voltage and current laws, ensures that the EM and circuit interactions can be formulated as a seamless system. While rigorous port models for EM structures can be obtained using the approach discussed herein, it is shown that the coupling paradigm can reveal additional details of the EM-circuit interactions and can provide a path to analysis-based design iteration.     

Interconnection of state space structures and wave digital filters

State space structures (SSSs) and wave digital filters (WDFs) are two major paradigms for the realization of digital filters. Both approaches are well established, but there are no proven methods for a mixed design of digital filters consisting of parts which are realized as SSSs and parts realized as WDFs. This contribution shows how to add a wave port to the conventional SS representation. This wave port allows to interconnect SSSs and WDFs without creating delay-free loops. Such interconnections allow to build discrete-time structures by reusing existing designs from both classes of digital filters.     

高隔离度宽带双极化微带天线设计

双极化天线由于具有极化分离的优异性能,在无线通信系统中引起了广泛关注,因此本文设计了一个高隔离度宽带双极化微带缝隙天线.为了获得高隔离度特性,该天线采用两个不同结构的微带线馈电,分别激励起垂直极化和水平极化模式.同时在地板上开缝隙来展宽天线带宽和实现天线的小型化.仿真优化结果表明,该天线端口1和端口2的阻抗带宽分别为51%和62%,在1.71GHz~2.69GHz整个工作频带范围内两端口之间的隔离度高于40dB,且结构简单,适用于移动通信的实际应用中.     

Analysis of microstrip discontinuities by FDTD method combined with SOC technique

In this paper, the application of the finite-difference time-domain (FDTD) algorithm combined with the short-open calibration SOC technique to three-dimensional microstrip discontinuity is presented. This SOC technique is directly accommodated in the FDTD algorithm. It is used to remove the unwanted parasitic errors brought by the approximation of the impressed voltage sources and the feed lines. The FDTD is formulated in such a way that the port voltages and currents are explicitly represented through relevant network matrices. This new method is also used to analyze finite periodic structures. The scattering parameters of the whole periodic structure can be approximately obtained through analyzing only one cell of it. The results for microstrip discontinuities and finite periodic structures are compared with the conventional FDTD method.     

A Simple Method for Millimeter-Wave Finline Balanced Mixer Design Using Three-Dimensional Field Simulation Software

In this paper, a simple method for millimeter-wave finline balanced mixer design using three-dimensional field simulation software has been proposed. The method can be widely used to design the diode-based circuits, especially for the circuit structures with orthogonal field in some specific hybrid integrated circuits which are unavailable to be designed using the circuit simulator. In these circuits, the power directly at diodes is correlated to the input reflection coefficient. The diodes mounted on the finline circuits are defined as impedance boundary in the commercial computer-aided design (CAD) tool High Frequency Structure Simulator (HFSS) model, and hence simulation with the use of HFSS can be implemented to optimize the input matching network of the finline circuits for transferring maximum power to the diodes. Two finline balanced mixers at U-band using commercial GaAs Schottky diodes have been designed and fabricated to validate this method. Matching structures at the radio frequency (RF) port have been employed for a better return loss and a lower conversion loss. Experiment results are presented and show good agreement with simulation data. The proposed method has proven to be useful for the design of millimeter-wave mixers in finline technique.     

Reactively controlled directive arrays

The radiation characteristics of anN-port antenna system can be controlled by impedance loading the ports and feeding only one or several of the ports. Reactive loads can be used to resonate a real port current to give a radiation pattern of high directivity. The theory of resonance is extended to include complex port currents and impedance loads. The initial design of an array is obtained by resonating a desired port current vector, which is then improved by an optimum seeking univariate search method. The direction of maximum gain can be controlled by varying the load reactances. Several numerical examples are given for a circular array of seven dipole elements.     

Slit coupled E-plane rectangular T-junctions using single port modematching technique

A new simple mode matching method, called single port mode matching technique (SPMMT) for modeling rectangular waveguide T-junctions is presented. The reflection coefficient at port 2 (side arm of the T-junction) is computed with both ports 1 and 3 shorted. The three-port scattering matrix of the T-junction is obtained from nine reflection coefficient computations using different short circuit lengths in ports 1 and 3. This method is rigorous, simple, reduces the computational effort significantly and can be applied to other structures. Comparison of S-parameters with classical equivalent circuit in Marcuvitz(1951) and new equivalent circuit given by Lampariello and Oliner(1993) is presented. Dependence of S-parameters on the slit thickness is also given. Open T-junctions are analyzed as a special case of the slit T-junction, and the results are in good agreement with experimental measurements     

一种端口速率可变的共享存储器交换

针对局域网和城域网中的多种数据传输速率结构,该文提出了一种共享存储器交换结构,在普通共享存储器交换结构的基础上,对支持可变的端口速率,以及支持变长数据包交换进行了改进,所提出的交换结构还具有自同步特点,即各输入输出端口之间不需要全局同步;同时还考虑了对变长数据包的队列管理。     

在光缓存器中节省光延迟线的技术

使用光纤延迟线(FDL)是构造全光缓存器的基本手段.但在当前提出的全光缓存器设计中,FDL利用率即缓存容量与所使用的FDL总长度之比是相当低的(通常为2/N,其中N为输入端口数).为了解决这个问题,提出了两种新的FDL组织形式:线性结构和树状结构,用于代替传统设计方法中功能相同的FDL模块.这种方法可以应用在多种光缓存器设计中,将FDL利用率提升至一个与N无关的常量或是1/log2N,节省效果是十分显著的.     

中西文终端辅口与常用外设的连接

中西文终端辅口（COM2）与外部设备连接，运用面广泛，涉及问题也较多。特别是不同型号之间的设备连接，经常会遇到不能正常使用的现象，要解决好这个问题，可以归结为两个方面；首先，要分析和完善终端、外部设备的端口信号的基本定义，两个端口之间的对应引脚信号的硬件连接，其次，要熟悉和掌握所使用的中西文终端对辅口操作的控制命令序列，并将此灵活的运用在设计的程序中。最终实现对终端辅口和外部设备的控制与操作。     

用于HDTV视频解码器的高性能SDRAM控制器

该文提出了一种适用于HDTV视频解码器的高性能SDRAM控制器。通过为SDRAM控制器设置多个端口并集成仲裁功能,该SDRAM控制器可以取代传统的总线＋DMA结构,为解码器中的功能单元有效地分配存储器的带宽资源。该文提出的SDRAM控制器内建流水线式的地址和数据路径,配合SDRAM本身流水处理指令的特性,能够无延时地处理各个端口上的存储器访问请求,从而降低了对片上缓存的需求。仿真综合结果表明,该文设计的SDRAM控制器满足HDTV解码的性能要求,且与总线＋DMA结构相比,片上缓存容量减少了约70%。     

含受控源单口网络的等效电阻的一种求解法

介绍了含受控源单口网络的等效电阻的一种求法。该方法尤其适用于受控源的控制量能方便地表示成端口电流或端口电压的等效电阻的求解。     

一种网络化虚拟仪器实验教学的管理模式

本文主要基于LabVIEW的DataSocket远程通信技术,设计了两种服务测控端—主(教师)客户端—次(学生)客户端之间的数据传输与控制系统。它们都能在实验教学中实现远程测控及师生之间的随时互动,从而建构了一种有效地管理网络化虚拟仪器实验教学的模式。     

New Concepts in Traveling-Wave Amplifiers (Short Paper)

Two new networks with the potential for good port VSWR over very broad bandwidths are proposed for use in both low-power balanced amplifiers, and high-power combining systems. These new structures which are called Low-Sidelobe and Squintless Traveling-Wave Amplifiers (LSTWA and SQTWA, respectively) have been derived from conventional Traveling-Wave Amplifiers (TWA) by utilizing Phased Array Antenna concepts and design techniques. Using Monte-Carlo simulations the relative performance of the three structures is compared. Finite loss and mismatch effects are also considered.     

A Novel Circuit Architecture for High Performance of High-order Subharmonic Mixers

A novel circuit architecture for high performance of high-order subharmonic (SH) mixers is proposed in this paper. According to the specified harmonic mixing order, one or more mixer diodes sub-arrays and corresponding power divider as well as phase shift network for RF and LO signals are arranged in the circuit. This proposed SH mixer circuit has improved conversion loss, wide dynamic range and high port isolation for high-order SH mixers. By phase cancellation of idle frequencies, the proposed SH mixer circuit can eliminate complicated design procedure of idle frequency circuits; by phase cancellation of leakage LO power to RF and IF port, and leakage RF power to LO port, the mixer circuit can get high port isolation in LO-IF/RF and RF-LO. The increased antiparallel diode pairs in each sub-array will also lead to well performance by lowering effective series resistance. The proposed SH mixer circuit can be easily realized with power divider and phase shift network for RF and LO signals.     

Two port frequency reconfigurable antenna for cognitive radios

A two port frequency reconfigurable antenna for cognitive radios is presented. It is composed of a disc monopole with two ports that excite at opposite sides; one port is very wideband and consists of a coplanar feed line and the other port is tunable narrowband and consists of a microstrip feed line with defect slots in its ground plane. The slots act as a filter that suppresses frequencies outside the desired band, its operating frequency band can be tuned by varying the length of the slots. The two ports are decoupled by at least 10 dB through the considered frequency range. It is believed that the proposed antenna can be a good candidate for cognitive radios in generic small base stations where the narrowband port is used for operation and the wideband one is used for sensing the spectrum. For accuracy, it is important that the sensing (measurement of the interference noise) is made with the same polarisation as the operation and the proposed antenna achieves this by having the two collinear ports. To examine the presented approach, simulated and measured results are presented and good agreement is reported.