Fast, accurate and simple approximate analytic formulas forcalculating the parameters of supported coplanar waveguides for (M)MIC's

Fast, accurate, and simple approximate analytic formulas are presented for calculating the quasi-static-TEM parameters of supported coplanar waveguide (SCPW) structures. These include the open, covered as well as dielectric over-layed SCPWs. These formulas have been designed for use in (M)MICs CAD programs and are only valid whenever the supporting material is of lower permittivity. Comprehensive comparisons have been made by using a rigorous spectral-domain hybrid mode analysis. Accuracy is found to be better than 1% for most of the operating range of physical dimensions and available dielectric materials (∈_r =1 to 20). Numerical results are also presented in order to investigate the properties of different SCPW structures     

A compact coupler design using meandered line compact microstrip resonant cell (MLCMRC) and bended lines

Wireless Networks - In this paper, a novel branch-line coupler using meandered line compact microstrip resonant cell (MLCMRC) and bended lines is proposed. The presented coupler works at...     

Design technique and performance assessment of new multiportmultihole power divider suitable for M(H)MICs

Novel power-dividing structures are studied for application in solid-state power amplifiers and array-antenna related beam-forming networks. This paper is directed to the design and study of a class of compact sinusoidally tapered power dividers suitable for use in monolithic and hybrid microwave integrated circuits at microwave and millimeter-wave frequencies. An efficient computer-aided design (CAD) technique is used in the accurate design of such planar circuits generally having irregular topologies and contours. A so-called multiport and multihole power divider is developed and modeled and a 1-9 power divider is designed through a cascading of four sets of 1-3 simple multihole dividers. Compared to conventional structures, advantageous features of the new power divider are demonstrated such as small size, short linearly aligned ports, potential high-power handling capability, potential large bandwidth, and easy post-fabrication tuning. Capacity of the proposed CAD technique is shown in the design of an electrically large multiport power dividing circuit for which only limited computer resource and time are required. Electrical performance and design effectiveness of the new multiport and multihole divider are assessed with design prediction and experimental results for Ku-band prototypes     

Characterization of finite-ground CPW reactive series-connectedelements for innovative design of uniplanar M(H)MICs

A variety of finite-ground coplanar waveguide (FGCPW) reactive series-connected capacitive and inductive elements are extensively studied and characterized as equivalent-circuit models that include complex parasitic effects caused by finite-ground widths. These models are developed by implementing a numerical calibration procedure called short-open calibration, which is used to extract characteristic parameters of the circuit model from full-wave method-of-moments calculations. The proposed model is generally described as an equivalent series admittance (Y_g) or impedance (Z_g) together with a pair of shunt admittances (Y_p) for FGCPW series-connected structures. With the new scheme, the FGCPW elements of interest behave like lossless lumped elements at low-frequency range, consisting of a series capacitance or inductance, as well as two shunt capacitances. As frequency increases, however, Y_g and Z_g exhibit a frequency-related dispersion and also a lossy resonance behavior, which stand for some added inductive or capacitive coupling effect caused by the extent of finite-ground width. On the other hand, unbounded radiation effect, considered in this model, appears too strong to be ignored around resonance. Theoretical and experimental results that compare very well with each other are shown for interesting electrical behaviors of finite-ground structures. An innovative uniplanar three-stage bandstop filter is designed and measured on the basis of its simplified equivalent-circuit model     

New technique for 2-port measurement using an 8-port directional coupler

It is shown that the complex scattering parameters of an arbitrary 2-port can be determined using an 8-port microwave network of suitable design and five power sensors.     

A square ring on square ring (SoS) ceramic strength testing technique for VLSI packaging

This paper describes a square ring on square ring (SoS) strength testing technique for reliability evaluation of ceramic pin grid array (PGA) packages. The unique features of this new technique are that the residual stresses are included in the strength results and that the package does not have to be cut, ground, or modified in any way to test the strength. The testing procedure is simple: after the fixture is calibrated for coplanarity, the package is placed in the SoS apparatus and force is applied until the ceramic fails. The ultimate force to failure is then converted into ceramic strength by using Finite Element Modeling (FEM). This paper also discusses failure analysis of ceramic packages that have been tested to failure with the SoS technique, ceramic strength and statistics, and verification of FEM models. The SoS apparatus consists of cantilevered beams and the free end of the beams come into contact with the edge of the package; therefore, the fixture conforms to the contour of the package during testing. This strength testing technique is currently being used to monitor the changes in strength and Weibull slope of PGAs. It is also being used for reliability evaluation of the heat sink side and cavity side of PGAs as received from suppliers and during the various stages of assembly/environmental processes.     

Simple technique for fabricating limited coupler gratings byholographic method using standard thick photoresist

The fabrication of photoresist gratings is considered. A solution to the problem of `transversal standing waves' is given and appears simple and versatile     

Experiment for bidirectional communication at same frequency using internally bypassed star coupler and coherent multichannel technique

The first realisation and operation of a representative part of a 72 subscriber star coupler designed for full duplex communications with doubled channel count is reported. Error free operation with coherent multichannel communications has been proved.<>     

具有方波输出谐振逆变桥的直流——直流变换器的分析和设计

本文从具有方波输出谐振逆变桥的直流—直流变换器的基本结构出发,通过对电路元件进行简化处理,详细分析了电路在不同工作时限的输出特性,获得了开关的最小关断时间,进而以上述结论为依据,提出了这种电路的一种简单的设计方案.     

Integrated optical inverter using light amplifying optical switch (LAOS)

An integrated optical inverter is demonstrated. Experimental results show good static input/output characteristics and an on/off ratio suitable for integrated optical logic. The simplicity of this circuit allows compact integration.<>     

Design and fabrication of 180/spl deg/ hybrid ring coupler for applications of MMICs using dielectric-supported air-gapped microstriplines

A 180/spl deg/ hybrid ring coupler has been designed and fabricated to prove the possibility of the fabrication for various passive components at high frequency using newly proposed transmission lines, i.e. dielectric-supported air-gapped microstripline structures.     

Modeling and design of a neutral-point voltage regulator for a three-level diode-clamped inverter using multiple-carrier modulation

The three-level diode-clamped multilevel converter commonly called the neutral-point-clamped converter has become established to be a preferred topology for high-power motor drive applications operating at several kilovolts. Although solutions to the problem of maintaining a stable neutral-point voltage in the converter continue to be the topic of research, a simple solution based on a design-oriented dynamic model of the system is not widely known. This paper presents the design, analysis, and implementation of a simple neutral-point voltage regulator for a three-level diode-clamped multilevel inverter, which uses a multiple-carrier sine-triangle modulator in conjunction with a closed-loop controller for neutral-point regulation. Redundant state choices are controlled via a continuous offset voltage that regulates the dc injection into the midpoint of the dc bus. A small-signal transfer function is developed in closed form, for neutral-point regulation, with the voltage offset as the control variable. Besides maintaining dc-bus voltage balance, the use of the approach leads to a significant reduction in the voltage distortion at the neutral point, allowing a definitive reduction in the required dc bus capacitance. Analytical, computer simulation, and experimental results verifying the approach are presented in this paper.     

Analysis and design of a DC/DC converter using square-wave outputresonant inverter

The operating modes of a square-wave output resonant inverter when used in a high-frequency link DC/DC converter are presented and analyzed. The condition of minimum turn-off time for the switches in the discontinuous current mode is obtained. A simple design procedure for the DC/DC converter is presented and illustrated by an example. Experimental results obtained from a prototype converter are presented to verify the theory     

Si-nanowire CMOS inverter logic fabricated using gate-all-around (GAA) devices and top-down approach

We present the monolithic integration of gate-all-around (GAA) Si-nanowire FETs into CMOS logic using top-down approach. Inverters are chosen as the test vehicles for demonstration. Empirically optimized designs show sharp ON–OFF transitions with high voltage-gains (e.g., ΔV_OUT/ΔV_IN up to ～45) and symmetric pull-up and pull-down characteristics. The matching of the drive currents of n- and p-MOSFETs is achieved using different number of nanowire channels for N- and P-MOS transistors. The inverter maintains its good transfer characteristics and noise margins for wide range of V_DD tested down to 0.2 V. The detailed experimental characterization is discussed along with the electrical characteristics of the individual transistors comprising the inverter. The performances of the inverters are discussed vis-à-vis those reported in the literature using advanced non-classical device architectures such as FinFETs. The integration potential of GAA Si-nanowire transistors to realize CMOS circuit functionality using top-down approach is thus demonstrated.     

Linearity of bulk-controlled inverter ring VCO in weak and strong inversion

In this paper linearity of frequency modulation in voltage controlled inverter ring oscillators for non feedback sigma delta converter applications is studied. The linearity is studied through theoretical models of the oscillator operating at supply voltages above and below the threshold voltage of a transistor, bringing the transistors in respectively strong and weak inversion. The theoretical results are tested with more advanced models through spectreRF simulations. A soft rail approach implemented to improve linearity in weak inversion is proposed and demonstrated. The influence from voltage noise, process variations and temperature variations have also been simulated to indicate the advantages of having the soft rail bias transistor in the VCO.     

M2M业务和H2H业务共存策略研究

随着M2M业务发展扩张,网络在H2H业务原本的矛盾上又增加了一系列新问题,研究怎样在解决新问题的同时满足M2M业务需求是一个迫切的工作。文章在对M2M业务充分分析的基础上,重点讨论M2M和H2H业务的共存策略,并针对共存策略中的过载技术进行详细论述,最后对M2M业务的市场发展进行了初步分析,并为移动运营商在M2M领域的发展提出建议。     

用于HCN激光器耦合输出的F-P腔的优化设计

本文介绍一种由双面金属栅网构成的F-P腔式激光耦合输出端,改变其间距,透过率可连续变化。将栅网等效为一导纳,利用等效电路方法,进行模拟计算。经优化计算得到一组最佳栅网参数。     

A single-mode optical fiber ring resonator using a planar 3×3fiber coupler and a Sagnac loop

We present the first theoretical analysis of an optical fiber ring resonator using a planar 3×3 fiber directional coupler and a fiber Sagnac loop. In the planar 3×3 fiber directional coupler, the three fibers inside the coupler lie in the same plane. Expressions for the circulating (resonant) and the output fields of the fiber ring resonator are obtained. It is found that this fiber ring resonator has a special property where there are two or more main resonance peaks or dips inside a period 2π of the phase change of the fiber ring resonator. This ring resonator may have applications as a sensor with high-phase sensitivity and a densely spaced two-channel wavelength division multi/demultiplexer     

Phase local approximation (PhaseLa) technique for phase unwrap from noisy data.

The local polynomial approximation (LPA) is a nonparametric regression technique with pointwise estimation in a sliding window. We apply the LPA of the argument of cos and sin in order to estimate the absolute phase from noisy wrapped phase data. Using the intersection of confidence interval (HCI) algorithm, the window size is selected as adaptive pointwise varying. This adaptation gives the phase estimate with the accuracy close to optimal in the mean squared sense. For calculations, we use a Gauss-Newton recursive procedure initiated by the phase estimates obtained for the neighboring points. It enables tracking properties of the algorithm and its ability to go beyond the principal interval [-pi, pi] and to reconstruct the absolute phase from wrapped phase observations even when the magnitude of the phase difference takes quite large values. The algorithm demonstrates a very good accuracy of the phase reconstruction which on many occasion overcomes the accuracy of the state-of-the-art algorithms developed for noisy phase unwrap. The theoretical analysis produced for the accuracy of the pointwise estimates is used for justification of the HCI adaptation algorithm.